Patent Description:
Whether it is the offshore, refinery, power, petrochemical, or paper and food industries, heat exchangers are often the core of the above-enumerated objectives. Numerous configurations of heat exchangers are known and used for a variety of applications. One of the widely used configurations of heat exchangers is a shell and tube heat exchanger, as shown in <FIG> by way of example. The shell and tube heat exchanger of <FIG> includes a cylindrical shell <NUM> that houses a bundle of parallel tubes <NUM>, which extend between two end plates <NUM>. A first fluid <NUM> flows in and through the space between the two end plates so as to come into contact with the bundle of parallel tubes <NUM>, through which a second fluid <NUM> passes through. To provide an improved heat exchange between the two fluids, the flow of the first fluid <NUM> is defined by intermediate baffles <NUM> forming respective compartments, which are arranged so that the flow of the first fluid <NUM> changes its direction in passing from one compartment to the next. The baffles <NUM>, configured as circular segments, are installed perpendicular to a longitudinal axis <NUM> of the shell <NUM> to provide a zigzag flow <NUM> of the first fluid <NUM>.

Disadvantageous, in shell and tube heat exchangers, such as the heat exchanger shown in <FIG>, the second fluid has to sharply change the direction of its flow several times along the length of the shell. These sharp changes in flow direction cause a reduction in the dynamic pressure of the second fluid and non-uniform flow velocity thereof, which, in combination, adversely affect the performance of the heat exchanger. Further, cleaning of shell and tube heat exchangers requires that the bundle of parallel tubes <NUM> be removed from the shell <NUM> or else only clean fluids can be used as the first fluid <NUM> that is flowed within the shell <NUM> of the shell and tube heat exchanger. Making the bundle of parallel tubes <NUM> removable requires sufficient clearance between the bundle of parallel tubes <NUM> and the shell <NUM> to allow for non- damaging removal. Typically the gap between the bundle of parallel tubes <NUM> and the shell <NUM> is large enough that a significant amount of the first fluid <NUM> to be heated or cooled will bypass the bundle of parallel tubes <NUM> and mix with the first fluid <NUM> that has been heated or cooled at the outlet of the shell and tube heat exchanger.

Referring still to shell and tube heat exchangers ( e. g the heat exchanger shown in <FIG>), it is well known that a perpendicular position of baffles relative to the longitudinal axis of the shell results in a relatively inefficient heat transfer rate/pressure drop ratio, because the baffles produce a large form drag. Adjacent baffles extending parallel to one another and at a right angle with respect to the longitudinal axis of the shell define a cross flow path characterized by numerous sharp turns between adjacent channels. The efficiency of heat transfer can be improved by reducing the spacing between the baffles. However, decreasing the spacing results in large recirculation zones and forces a larger fraction of the flow to leak between the tubes and the baffle and along the outer edges of the baffles. The non-uniformity of flow distribution within each segment defined between the adjacent baffles causes numerous eddies, stagnation regions, and expansion/contraction, which decreases a local temperature difference. A further factor contributing to a decreased heat transfer rate is attributed to the fact that the tubes traversed by the first fluid have to be positioned at a certain radial distance from the shell. Accordingly, the cross flow around the peripherally located tubes is faster than around centrally mounted tubes.

Thus, conventional baffle arrangement as described above results in flow bypass through baffle-to-shell clearances and flow leakage through tube-to-baffles clearances. Bypass and leakage flow reduces the cross-flow heat transfer while the flow maldistribution caused by significant velocity variations increases back-flow and eddies in the dead zones, which in turn leads to the disposition of fouling materials on the outside of the tubes of the bundle of tubes. If the heat exchanger is left to continue operating after disposition of fouling materials within the shell, then a significant loss in performance will be experienced overtime, which will translate into an increase in operating cost and consumption of energy. If the heat exchanger is removed from service to be cleaned due to the buildup of fouling materials, there will be a loss or reduction in production, which translates into an operating cost similar to or higher than the value of the heat exchanger. Further, heat exchangers that are left in a fouled state for too long will develop hardened deposits, which will be difficult to remove and can cause corrosion in local regions with higher temperatures. The bundle of tubes on which the hardened deposits develop and on which corrosion occurs may deteriorate to a point where the bundle of tubes must be removed from service and the damaged tubes are plugged.

Furthermore, conventional arrangement may experience flow-induced vibration of the tubes since long tubes reaching often <NUM>-feet long are supported by a succession of baffles which, in order to solve the problem associated with the non- uniform velocity, are spaced apart at a substantial distance.

Helically baffled heat exchangers have been used to overcome the problem of non-uniform flow in shell and tube heat exchangers. A helical pattern of the first fluid flow may allow for a particularly effective conversion of available pressure drop to heat transfer and may reduce the risk of vibration of the bundle of parallel pipes. However, the helical baffles may have large gaps which allow the first fluid flow to leak around the baffles and may result in both a reduced velocity across the bundle of tubes and a lower thermal efficiency due to the loss of a temperature driving force. These problems may particularly occur when a removable bundle of tubes with a large tube to shell clearance is desired. Further, bypassing of the bundle of tubes may also be particularly severe when cooling a viscous liquid whereby the viscosity of a liquid after it has been cooled is significantly higher than the viscosity of the liquid when it enters the heat exchanger. In other words, a warmer, less viscous liquid can easily flow around and bypass the bundle of tubes compared to a cooled, more viscous liquid.

<CIT>, for instance, relates to an early helical heat exchanger. <CIT> discloses a baffle arrangement form of the shell-and-tube heat exchanger, particularly for petroleum chemical industry use. The heat exchanger mainly is made of a housing, a heat-exchanging tube bundle and deflection plates, each deflection plate being a helical baffle. The helical baffles each have pitch made of four elliptic sector flat boards.

<CIT> relates to a heater assembly including a continuous series of perforated helical members and a plurality of heating elements. The perforated helical members cooperate to define a geometric helicoid disposed about a longitudinal axis of the heater assembly. Each perforated helical member defines opposed edges and a predetermined pattern of perforations. The perforations extend through each perforated helical member parallel to the longitudinal axis. The heating elements extend through the perforations. <CIT> discloses a heat exchanger according to the preamble of claim <NUM> and relates to a heat exchanger including: a shell configured to have an inlet and an outlet for a first fluid; baffles disposed in the shell, wherein the baffles are configured to guide the first fluid into a helical flow pattern, and at least some of the baffles are disposed in a helical pattern with a helix angle; a tube disposed in the shell, wherein the tube extends along a longitudinal axis of the shell, the tube passes through the baffles, and the tube is configured to facilitate an exchange of thermal energy between a second fluid within the tube and the first fluid; and fins fixedly attached to an outer surface of the tube, wherein at least some of the fins are angled to match the helix angle of the at least some of the baffles.

In order to help prevent bypass of the baffles of a helically baffled heat exchanger, sealing devices have been used. The sealing devices for such helically baffled heat exchangers have been of substantially the same type as the sealing devices used for the conventional baffles and have been relatively ineffective in preventing bypass in the helically baffled heat exchangers. In addition, since the helically baffled heat exchangers have a generally lower pressure drop than a segmentally baffled heat exchanger, the penalty associated with the pressure drop induced by the sealing devices relative to the improvement in heat transfer is relatively high. The sealing devices used in conventional baffled heat exchangers may provide, at best, a minor improvement in heat transfer, and may, at worst, interfere with the helical flow path in the bundle, thereby causing a significant reduction in heat transfer.

It is desirable to configure a baffle assembly that can attain uniformity of fluid flow without recirculation, dead zones, or leakage/bypassing of the heat transfer surfaces. Further, it is desirable to configure a baffle assembly with positioning of multiple baffles and sealing devices to maintain a higher heat transfer rate within acceptable pressure drop and vibration limits. Additionally, a baffle assembly that allows for facilitated maintenance of the bundle of tubes by providing a larger tube to shell clearance to allow rapid removal and replacement for cleaning and repair is desirable. Embodiments disclosed herein address one or more of these.

In a first aspect the objects of the present invention are solved by the features of the independent apparatus claim <NUM>. Preferred embodiments of the apparatus are given in the dependent claims <NUM>-<NUM>.

In some embodiments, the seal strips, in part, may be configured to direct a flow of fluid helically toward the outlet. The first plurality of seal strips may be disposed from a distal side of a first baffle from adjacent to a proximal radial edge of the first baffle to a proximal side of a second baffle adjacent to a distal radial edge of the second baffle, wherein the first and second baffles are located in a same sector or quadrant. Alternatively, the first plurality of seal strips may be disposed from a distal side of a first baffle from intermediate the proximal radial edge and distal radial edge of the first baffle to a proximal side of a second baffle intermediate a proximal radial edge and a distal radial edge of the second baffle, wherein the second baffle is located in a different sector or quadrant than the first baffle.

The first end of each of the first plurality of seal strips may, in some embodiments, be coupled to the distal side of a first of the plurality of baffles, and the second end of each of the first plurality of seal strips may be coupled to the proximal side of a second of the plurality of baffles.

The first plurality of seal strips may each have an inner surface and an outer surface. The first plurality of seal strips may be angled from the outer surface to the inner surface by an angle from orthogonal to the shell in the direction defined from a proximal radial edge to a distal radial edge of the one of the plurality of baffles.

An outer surface of each of the first plurality of seal strips may be disposed substantially proximate to an inner surface of the shell. An inner surface of each of the first plurality of seal strips, in some embodiments, may be spaced from an outer diameter of a closest tube of the plurality of axially extending tubes by a distance that is equal to a distance between outer diameters of two adjacent tubes of the plurality of axially extending tubes.

Each of the plurality of baffles may include at least one of the first plurality of seal strips coupled to the proximal side and at least one of the first plurality of seal strips coupled to the distal side of the baffle. In some embodiments, each of the first plurality of seal strips coupled to the distal side of each of the plurality of baffles may be offset rotationally about the longitudinal axis from each of the plurality of seal strips.

In another aspect the objects of the present invention are solved by the features of the independent method claim <NUM>. Preferred embodiments of the method are given in the dependent claims <NUM>-<NUM>.

The coupled first plurality of seal strips may each have an inner diameter and an outer diameter. In some embodiments, coupling the first plurality of seal strips may further include: angling the coupled first plurality of seal strips from the outer diameter to the inner diameter by an angle from orthogonal to the shell in the direction defined from the proximal radial edge to the distal radial edge of the one of the plurality of baffles. In some embodiments, coupling the first plurality of seal strips may further include: spacing an inner diameter of each of the first plurality of seal strips from an outer diameter of a closest tube of the plurality of axially extending tubes by a distance that is equal to a distance between outer diameters of two adjacent tubes of the plurality of axially extending tubes. And, in some embodiments, coupling the first plurality of seal strips may further include rotationally offsetting each of the first plurality of seal strips coupled to the distal side of each of the plurality of baffles from each of the plurality of seal strips coupled to the proximal side of each of the plurality of baffles.

The method of assembly may further include coupling a second plurality of seal strips having a first end and a second end radially between the shell and the plurality of axially extending tubes. Coupling the second plurality of seal strips may include: coupling the first end of each of the second plurality of seal strips to the proximal radial edge of the distal side of one of the plurality of baffles; and coupling the second end of each of the second plurality of seal strips to the distal radial edge of the proximate side of another of the plurality of baffles, wherein each of the second plurality of seal strips extends parallel to the longitudinal axis of the shell. may be parallel to a longitudinal axis of the heat exchanger in some embodiments.

Other aspects and advantages of the invention will be apparent from the following description and the appended claims.

Embodiments of the present disclosure are described below in detail with reference to the accompanying figures. Like elements in the various figures may be denoted by like reference numerals for consistency. Further, in the following detailed description, numerous specific details are set forth in order to provide a more thorough understanding of the claimed subject matter. However, it will be apparent to one having ordinary skill in the art that the embodiments described may be practiced without these specific details.

Referring to <FIG>, in one or more embodiments, a helically-baffled heat exchanger <NUM> according to one or more embodiments of the present disclosure is shown. The heat exchanger <NUM> may include a shell <NUM> through which a first fluid is passed, a plurality of axially extending tubes <NUM> through which a second fluid is passed, and a plurality of elliptical sector-shaped baffles <NUM>. By "elliptical sector-shaped," it should be understood that the baffles take the general form of an elliptical sector, which geometrically includes a region bounded by an arc and line segments connecting the center of the ellipse (the origin) and the endpoints of the arc, but may not be inclusive of the entire sector so as to account for other components of the heat exchanger (tubes, etc.) and the manner of installation of the baffle (e.g., encompassing or abutting a central tube, or accommodating tubes along the periphery of the elliptical sector, as illustrated in <FIG> and <FIG>, for example).

The shell <NUM> may include an inlet <NUM> and an outlet <NUM> between which the first fluid may pass within the shell <NUM>. Each of the baffles <NUM> may be positioned at an angle λ relative to a line (N-N) that is normal to a longitudinal axis <NUM> of the shell <NUM> in order to guide a first fluid flow <NUM> into a helical pattern <NUM> across the shell <NUM> from the inlet <NUM> to the outlet <NUM>. The helical pattern <NUM> of the first fluid flow <NUM> may allow for an effective conversion of available pressure drop to heat transfer and reduced risk of vibration due to the fact that the unsupported tube length is minimized. In one or more embodiments, there may be no dead spots for fouling along the first fluid flow <NUM>, and the amount of heat transfer may be increased due to elimination of eddies or back mixing. Further, in one or more embodiments, a direction of the first fluid flow <NUM> may be opposite to a direction of a second fluid flow <NUM> within the tubes <NUM>. In other words, in one or more embodiments, the second fluid may flow in a direction that is substantially from the outlet <NUM> to the inlet <NUM>. Additionally, although the baffles <NUM>, as shown in <FIG>, are flat, in one or more embodiments, opposite sides of each baffle may be curved to guide the first fluid flow <NUM> along the helical pattern.

Referring now to <FIG>, a baffle cage <NUM> according to one or more embodiments of the present disclosure is shown. The baffle cage <NUM> may include successive baffles <NUM> positioned at an angle from normal to a longitudinal axis (not shown) of the baffle cage <NUM>, and the successive baffles <NUM> may be rotationally and longitudinally offset from each other such that a helical pattern is formed. The rotational offset between successive baffles <NUM> may be such that at least a proximal radial edge <NUM> of one baffle <NUM> overlaps or abuts a distal radial edge <NUM> of an adjacent baffle <NUM> in a longitudinal direction. For example, <FIG> illustrates an embodiment in which a proximal radial edge <NUM> of each baffle <NUM> overlaps a distal edge <NUM> of the successive baffle <NUM>. In one or more embodiments, a proximal radial edge <NUM> of each baffle <NUM> may be the radial edge of the baffle <NUM> that is axially closest to an inlet (not shown) of a shell (not shown) of a heat exchanger, and a distal radial edge <NUM> of each baffle <NUM> may be the radial edge of the baffle <NUM> that is axially farthest from the inlet of the shell of the heat exchanger. Further, in one or more embodiments, there may be an equal number of baffles <NUM> per <NUM>° rotation about the longitudinal axis about which the baffles <NUM> are disposed. Furthermore, the baffles <NUM> may support multiple tubes <NUM> and may guide a first fluid flow (not shown) in a helical path. Additionally, in one or more embodiments, the baffles <NUM> may be interconnected by a plurality of rods <NUM>. A spacer <NUM> may optionally be used during construction to ensure baffle spacing. As illustrated, spacer <NUM> is rectangular, although other shapes may be used. Still referring to <FIG>, in one or more embodiments, each of the baffles <NUM> may have an outer circumferential edge <NUM>, and each outer circumferential edge <NUM> may be spaced apart from the outer circumferential edge <NUM> of an adjacent baffle <NUM>. Each of the baffles may also include a proximal radial edge <NUM> at one end of the outer circumferential edge <NUM> and a distal radial edge <NUM> at the other end of the outer circumferential edge <NUM> such that the elliptical sector-shaped baffles <NUM> are defined by the outer circumferential edge <NUM>, the proximal radial edge <NUM>, and the distal radial edge <NUM>. Furthermore, each of the baffles may have a proximal side <NUM> and a distal side <NUM> that are opposite of each other as well as a plurality of spaced apart holes <NUM> that extend through the baffles <NUM> from the proximal side <NUM> to the distal side <NUM>. In one or more embodiments, a proximal side <NUM> of each baffle <NUM> may be the side of the baffle <NUM> that is axially closest to the inlet of the shell of the heat exchanger, and a distal side <NUM> may be the side of each baffle <NUM> that is axially farthest from the inlet of the shell of the heat exchanger. One tube <NUM> of the plurality of axially extending tubes <NUM> may pass through each of the holes <NUM> in the baffles <NUM>. In one or more embodiments, the holes <NUM> of one baffle <NUM> may align with holes on another baffle <NUM> such that the axially extending tubes <NUM> may fit through holes <NUM> and may be supported by multiple baffles <NUM>. It is noted that, while not illustrated on all baffles <NUM>, each of the baffles <NUM> may contain through holes <NUM>.

As illustrated in <FIG>, the tubes <NUM> and through holes <NUM> do not extend all the way to circumferential edge <NUM>. Thus, when installed within a shell (not shown), a gap would be present between the shell and the outermost tubes <NUM>. A tube cage <NUM>, according to embodiments herein, may include a plurality of seal rods or seal strips <NUM> disposed at an angle such that the fluid flowing through the shell is, at least in part, directed back towards the tubes <NUM>. Strips <NUM> may thus provide a dual function of enhanced sealing and structural support, decreasing the amount of fluid that may bypass the plurality of tubes as well as supporting the structure of the cage <NUM>.

In addition to the sealing and structural support function of the strips <NUM>, which may be referred to herein as seal strips, the strips <NUM> may be positioned in a manner so as to provide the sealing function with a low pressure drop, providing a flow barrier to prevent fluid flowing in the gap between the tubes <NUM> and the baffle edge <NUM> through the entirety of the helical flow path. The flow barrier function could alternatively be obtained by use of other structures, such as longitudinal strips having a substantially rectangular shape disposed such that the space between the tube bundle and the shell is effectively blocked; however such a flow barrier would come at the at the expense of a significant pressure drop. In contrast to longitudinal strips, embodiments herein are directed toward strips that are designed and oriented to provide enhanced sealing, structural support, and a relatively low pressure drop, as will be described more fully below.

Rods <NUM>, as described above, are optional and may be used to additionally serve the purpose of supporting baffles during tube insertion. Thus, although rods are shown to interconnect the baffles in <FIG>, in one or more embodiments of the present disclosure, rods are not necessary to support and interconnect the baffles <NUM>. Instead, as shown and described in further detail below, in one or more embodiments, strips may be used to support and interconnect the baffles about a center rod.

Referring now to <FIG>, baffles <NUM> according to one or more embodiments of the present disclosure are shown. In one or more embodiments, a plurality of baffles <NUM> may be coupled to a center rod <NUM> within a shell (not shown) of a heat exchanger (not shown). Successive baffles <NUM> may be positioned at an angle from normal to a longitudinal axis <NUM> of the center rod <NUM>, and the successive baffles <NUM> may be rotationally and longitudinally offset from each other such that a helical pattern is formed. The rotational offset between successive baffles <NUM> may be such that at least a proximal radial edge <NUM> of one baffle <NUM> overlaps a distal radial edge <NUM> of an adjacent baffle <NUM> in a longitudinal direction. In one or more embodiments, a proximal radial edge <NUM> of each baffle <NUM> may be the radial edge of the baffle <NUM> that is axially closest to an inlet (not shown) of a shell (not shown) of a heat exchanger, and a distal radial edge <NUM> of each baffle <NUM> may be the radial edge of the baffle <NUM> that is axially farthest from the inlet of the shell of the heat exchanger.

Still referring to <FIG>, in one or more embodiments, the baffles <NUM> may be elliptical sector-shaped. Each of the baffles <NUM> may have an outer circumferential edge <NUM>, and each outer circumferential edge <NUM> may be spaced apart from the outer circumferential edge <NUM> of an adjacent baffle <NUM>. Each of the baffles may also include a proximal radial edge <NUM> at one end of the outer circumferential edge <NUM> and a distal radial edge <NUM> at the other end of the outer circumferential edge <NUM> such that the elliptical sector-shaped baffles <NUM> are defined by the outer circumferential edge <NUM>, the proximal radial edge <NUM>, and the distal radial edge <NUM>. Furthermore, each of the baffles may have a proximal side <NUM> and a distal side <NUM> that are opposite of each other as well as a plurality of spaced apart holes <NUM> that extend through the baffles <NUM> from the first side <NUM> to the second side <NUM>. In one or more embodiments, a proximal side <NUM> of each baffle <NUM> may be the side of the baffle <NUM> that is closest to the inlet of the shell of the heat exchanger, and a distal side <NUM> may be the side of each baffle <NUM> that is farthest from the inlet of the shell of the heat exchanger. One tube of a plurality of axially extending tubes (not shown) may pass through hole <NUM> in the baffles <NUM>. In one or more embodiments, the holes <NUM> of one baffle <NUM> may align with holes on another baffle (not shown) such that the axially extending tubes may be supported by multiple baffles. Additionally, in one or more embodiments, each of the baffles <NUM> may include a center hole <NUM> at an intersection between the proximal radial edge <NUM> and the distal radial edge <NUM> through which the center rod <NUM> may pass in order to couple each of the baffles <NUM> to the center rod <NUM>. While only a few holes <NUM> are illustrated in <FIG>/B, one skilled in the art will understand that each baffle includes multiple holes, similar to those illustrated in <FIG> or <FIG>, for example.

The center hole <NUM> of each baffle <NUM> may be uniquely angled such that the baffles <NUM> are positioned at an angle from normal to a longitudinal axis <NUM> of the center rod <NUM>. Further, in some embodiments the baffle angle may vary along the length of the heat exchanger, such as where proximal baffles are disposed at a first angle to the longitudinal axis and more distal baffles are disposed at a different angle to the longitudinal axis. As another example, proximal baffles may be disposed at a first angle to the longitudinal axis and more distal baffles may be successively disposed at increasing or decreasing angles to the longitudinal axis.

Referring now to <FIG>, multiple views of a heat exchanger <NUM> according to one or more embodiments of the present disclosure are shown. In one or more embodiments, a heat exchanger <NUM> may include a shell <NUM> (<FIG>) through which a first fluid is passed, a plurality of axially extending tubes <NUM> through which a second fluid is passed, a plurality of elliptical sector-shaped baffles <NUM>, and a first plurality of seal strips <NUM> disposed between the baffles <NUM>. The shell <NUM> may include an inlet (not shown) and an outlet (not shown) between which the first fluid may pass within the shell <NUM>. Further, the plurality of tubes <NUM>, the plurality of baffles <NUM>, and the first plurality of seal strips <NUM> may be disposed within the shell <NUM>.

Referring to <FIG> and <FIG>, in one or more embodiments, the plurality of baffles <NUM> may be disposed such that successive baffles <NUM> are positioned at an angle from a line that is normal to a longitudinal axis <NUM> of the shell <NUM>. In one or more embodiments, the baffles <NUM> may be coupled to and disposed around a center rod <NUM>, and the successive baffles <NUM> may be rotationally and longitudinally offset from each other such that a helical pattern is formed. The rotational offset between successive baffles <NUM> may be such that at least a proximal radial edge <NUM> of one baffle <NUM> abuts or overlaps a distal radial edge <NUM> of an adjacent baffle <NUM> in a longitudinal direction. In one or more embodiments, a proximal radial edge <NUM> of each baffle <NUM> may be the radial edge of the baffle <NUM> that is axially closest to the inlet of the shell <NUM> of the heat exchanger <NUM>, and a distal radial edge <NUM> of each baffle <NUM> may be the radial edge of the baffle <NUM> that is axially farthest from the inlet of the shell <NUM> of the heat exchanger <NUM>. Further, in one or more embodiments, there may be an equal number of baffles <NUM> per <NUM>° rotation about the longitudinal axis <NUM> about which the baffles <NUM> are disposed. For example, in one or more embodiments, there may be four baffles <NUM> per <NUM>° rotation about the longitudinal axis <NUM> of the shell <NUM>. While four elliptical sector-shaped baffles per <NUM>° rotation about the longitudinal axis of the shell are shown, in one or more embodiments, any number of baffles of varying shapes per <NUM>° rotation about the longitudinal axis of the shell may be utilized as long as the baffles are longitudinally and rotationally offset such that a helical flow path is formed.

Still referring to <FIG> and <FIG>, in one or more embodiments, the baffles <NUM> may be elliptical sector-shaped. Each of the baffles <NUM> may have an outer circumferential edge <NUM>, and each outer circumferential edge <NUM> may be spaced apart from the outer circumferential edge <NUM> of an adjacent baffle <NUM>. Each of the baffles <NUM> may also include a proximal radial edge <NUM> at one end of the outer circumferential edge <NUM> and a distal radial edge <NUM> at the other end of the outer circumferential edge <NUM> such that the elliptical sector-shaped baffles <NUM> are defined by the outer circumferential edge <NUM>, the proximal radial edge <NUM>, and the distal radial edge <NUM>. Furthermore, each of the baffles <NUM> may have a proximal side <NUM> and a distal side <NUM> that are opposite of each other as well as a plurality of spaced apart holes <NUM> that extend through the baffles <NUM> from the proximal side <NUM> to the distal side <NUM>. In one or more embodiments, a proximal side <NUM> of each baffle <NUM> may be the side of the baffle <NUM> that is axially closest to the inlet of the shell <NUM> of the heat exchanger <NUM>, and a distal side <NUM> may be the side of each baffle <NUM> that is axially farthest from the inlet of the shell <NUM> of the heat exchanger <NUM>.

In one or more embodiments, one tube <NUM> of the plurality of axially extending tubes <NUM> may pass through holes <NUM> in the baffles <NUM>, and a direction of a second fluid flow within the tubes <NUM> may be opposite to a direction of a first fluid flow from the inlet of the shell to the outlet of the shell. Further, in one or more embodiments, the holes <NUM> of one baffle <NUM> may align with holes on another baffle <NUM> such that the tubes <NUM> may extend axially along an entire length of a heat exchanger <NUM> and such that each of the tubes <NUM> be supported by multiple baffles <NUM>. Furthermore, a distance <NUM> between outer diameters <NUM> of each of the tubes <NUM> that are disposed in each of the holes <NUM> may be consistent across the entirety of the plurality of tubes <NUM>. Additionally, as discussed above, in one or more embodiments, each of the baffles <NUM> may include a center hole <NUM> at an intersection between the first radial edge <NUM> and the second radial edge <NUM> through which the center rod <NUM> may pass in order to couple each of the baffles <NUM> to the center rod <NUM>. The center hole <NUM> of each baffle <NUM> may be uniquely angled such that the baffles <NUM> are positioned at an angle from the line normal to the longitudinal axis <NUM> of the shell <NUM>.

Further, referring to <FIG>, in one or more embodiments, a first plurality of seal strips <NUM> may each be disposed between a first baffle <NUM> and a corresponding, successive baffle <NUM> that is at least a full <NUM>° rotation from the first baffle <NUM>. Further, each of the first plurality of seal strips <NUM> may be disposed radially between the plurality of tubes <NUM> and an inner surface <NUM> of the shell <NUM>. In one or more embodiments, the inner surface <NUM> may have a diameter <NUM>. Further, in one or more embodiments, each of the first plurality of seal strips <NUM> may be coupled to each of the first baffle <NUM> and the corresponding, successive baffle <NUM>. In one or more embodiments, the first plurality of seal strips <NUM> may be disposed such that each of the first plurality of seal strips <NUM> are substantially orthogonal to the helical path defined by the baffles within the shell <NUM> of the heat exchanger <NUM>. Referring to <FIG>, <FIG>, in one or more embodiments, a first end <NUM> of each of the first plurality of seal strips <NUM> may be coupled to the distal side <NUM> of one of the plurality of baffles <NUM> between the proximal radial edge <NUM> and the distal radial edge <NUM>, and a second end <NUM> of each of the first plurality of seal strips <NUM> may be coupled to the proximal side <NUM> of another of the plurality of baffles <NUM> between the proximal radial edge <NUM> and the distal radial edge <NUM>.

As shown in <FIG> and <FIG>, in one or more embodiments, each of the first plurality of seal strips <NUM> may be disposed orthogonal to both the distal side <NUM> of one baffle <NUM> and the proximal side <NUM> of another baffle <NUM>. As shown in <FIG>, in other embodiments, each of the plurality of seal strips <NUM> may be connected between two baffles <NUM>. As illustrated in <FIG>, the seal strip <NUM> may be disposed such that an angle <NUM> is formed between the seal strip <NUM> and a line orthogonal to the proximal side <NUM> of one baffle <NUM> and the distal side of the other baffle <NUM>. In some embodiments, the angle <NUM> may be from greater than <NUM>° up to <NUM>°. In further embodiments, the angle <NUM> may be one of from greater than <NUM>° up to <NUM>°, from <NUM>° up to <NUM>°, from <NUM>° up to <NUM>°, or from <NUM>° up to <NUM>°. Due to the possible leakage of a first fluid between consecutive baffles of the plurality of baffles <NUM>, the direction <NUM> of the first fluid flow may vary slightly from the helical path formed by the plurality of baffles <NUM>. Further, due to this possible variance in the first fluid flow direction, the angle <NUM> of the seal strips <NUM> may vary such that each of the first plurality of seal strips <NUM> may be orthogonal to the helical first fluid flow direction <NUM>.

As shown in <FIG> and <FIG>, the baffles <NUM> may be disposed in four quadrants. In some embodiments, a seal strip <NUM> may connect a first baffle <NUM> to a second baffle <NUM> in the same quadrant (or the same sector where other than four baffles are used per <NUM>° rotation). The seal strip may be connected from the distal side <NUM> of the first baffle <NUM> to a proximal side <NUM> of the second baffle <NUM>, at a point adjacent to the distal edge <NUM> of the second baffle <NUM>, as described above. For example, the seal strip may connect the distal side <NUM> of a first baffle <NUM> from adjacent to the proximal edge <NUM> of the first baffle to the proximal side <NUM> of a second baffle adjacent to the distal edge <NUM> of the second baffle. As another example, the seal strip may connect the distal side <NUM> of a first baffle <NUM> from adjacent to the proximal edge <NUM> of the first baffle to the proximal side <NUM> of a second baffle adjacent to the proximal edge <NUM> of the second baffle.

In some embodiments, a seal strip <NUM> may connect a first baffle <NUM> to a second baffle <NUM> in an adjacent quadrant (sector). The seal strip may be connected from the distal side <NUM> of the first baffle <NUM> to a proximal side <NUM> of the second baffle <NUM>, as described above. For example, in some embodiments, the seal strip may connect the distal side <NUM> of a first baffle <NUM> from intermediate the proximal edge <NUM> and distal edge <NUM> of the first baffle to the proximal side <NUM> of a second baffle intermediate the proximal edge <NUM> and distal edge <NUM> of the second baffle.

In other embodiments, a heat exchanger may include some seal strips <NUM> that connect between baffles <NUM> in the same quadrant, while other seal strips <NUM> may connect between baffles <NUM> in adjacent quadrants.

In some embodiments, as shown in <FIG>, improved heat exchange and reduced pressure drop may be realized where the seal strips may, in part, direct flow helically toward the outlet. In other words, the seal strips <NUM> may be disposed at a helix angle Hs less than a helix angle HB of the baffles <NUM>, where the helix angle is defined as the angle of the baffle or seal strip relative to the longitudinal axis of the heat exchanger. In some embodiments, seal strip helix angle Hs may be in the range from greater than <NUM>° to <NUM>°, such as from a lower limit of <NUM>°, <NUM>°, <NUM>°, <NUM>°, <NUM>°, <NUM>°, <NUM>°, <NUM>°, or <NUM>° to an upper limit of <NUM>°, <NUM>°, <NUM>°, <NUM>°, <NUM>°, <NUM>°, <NUM>°, <NUM>°, or <NUM>°, where any lower limit may be combined with any greater upper limit according to embodiments herein. It has been found that in some embodiments, strips that have a helix angle Hs greater than a helix angle HB of the baffle, while providing better sealing, may disrupt the helical flow path of the fluid (i.e., trying to drive flow back toward the inlet). In contrast, where the seal strips encourage the helical flow, adequate sealing is provided while both reducing pressure drop (relative to a conventional seal) and improving heat transfer results. In various embodiments the baffle angle HB may be consistent or may vary along the length of the heat exchanger. When varying baffle angles are used, for example, proximal baffles may be disposed at a first angle (HB1, not shown) to the longitudinal axis and more distal baffles may be disposed at a second different angle (HB2, not shown) to the longitudinal axis. As another example, proximal baffles may be disposed at a first angle to the longitudinal axis and more distal baffles may be successively disposed at increasing or decreasing angles to the longitudinal axis (HB1 < HB2 < HB3 etc.).

As described above, in one or more embodiments, the first plurality of seal strips <NUM> may be disposed such that each of the first plurality of seal strips <NUM> are orthogonal or substantially orthogonal to the helical path defined by the baffles within the shell <NUM> of the heat exchanger <NUM>. In other embodiments, due to leakage and the possible variance in the first fluid flow direction, the angle <NUM> of the seal strips <NUM> may vary such that each of the first plurality of seal strips <NUM> may be orthogonal to the helical first fluid flow direction. While it is desirable for the fluid to flow as close to the geometric lead as possible, it is recognized herein that this is not always the case. Hence the fluid flow path may not be orthogonal to the seal strip <NUM> as shown. Leakage and the amount of change in the first fluid flow direction may also vary depending upon the properties of the fluid being conveyed and the shell and baffle dimensions. Embodiments herein may thus include estimating a first fluid flow direction, such as by computational fluid dynamics or other simulations or experimental investigations, such that the angle of the strip <NUM> may be installed accounting for the expected difference between the geometric helical lead and the actual fluid path such that the strip is orthogonal to the flow.

While embodiments shown in <FIG> may include a plurality of seal strips that are all disposed at the same angle between one baffle and another baffle, in one or more embodiments, the seal strips may be disposed at different angles within the heat exchanger. In other words, in one or more embodiments, one seal strip of the plurality of seal strips may be disposed orthogonal to both the distal side of one baffle and the proximal side of another baffle, and another seal strip of the plurality of seal strips may be disposed at an angle from orthogonal to the proximal side of one baffle and the distal side of the other baffle, in which the angle may be from greater than <NUM>° up to <NUM>°. Thus, while in one or more embodiments all of the seal strips may be disposed with the same angular disposition between baffles, in other embodiments, a combination of seal strips of different angular dispositions may be used. Further, while in one or more embodiments seal strips of a first angular disposition may be used between the baffles of the first several rotations about the longitudinal axis and seal strips of a second angular disposition may be used between the baffles of the remaining rotations about the longitudinal axis, in other embodiments, different patterns of seal strips of a first angular disposition and seal strips of a second angular disposition may be used. Furthermore, in one or more embodiments, seal strips of more than two angular dispositions may be used throughout the heat exchanger in different patterns.

Further, referring to <FIG>, in one or more embodiments, each of the first plurality of seal strips may have a curved inner surface <NUM> and a curved outer surface <NUM>. In one or more embodiments, the curved outer surface <NUM> of each seal strip <NUM> may be disposed substantially proximate the inner surface <NUM> of the shell <NUM>. Further, in one or more embodiments, the curved outer surface <NUM> of one or more of the seal strips <NUM> may have a clearance of <NUM>-<NUM> from the inner surface <NUM> of the shell <NUM>. For example, the curved outer surface <NUM> of one or more of the seal strips <NUM> may have a clearance of <NUM> from the inner surface <NUM> of the shell <NUM>. Additionally, a curvature of the curved outer surface <NUM> of the seal strips <NUM> may be elliptical in shape and may match a curvature of the inner surface <NUM> of the shell <NUM>. While noting that the seal strips may be elliptical, the appearance of the seal strips may vary with angle. For example, where Hs is small, the strips may be nearly straight. In contrast, where Hs is large, the strips will be elliptical. The elliptical shape ensures that each of the space between the shell and the strip and the space between the tube bundle and the strip may be the same along the length of the strip. Further, as the strips are elliptical, the strips may be represented by a minor diameter and a major diameter (not shown), where the shell diameter, spacing from the shell diameter, and the strip angle Hs may define the elliptical nature of the strip.

Furthermore, in one or more embodiments, a curvature of the curved inner surface <NUM> of each of the first plurality of seal strips <NUM> may be elliptical in shape and the curvature of the inner surface <NUM> may be different than the curvature of the outer surface <NUM> of each of the first plurality of seal strips <NUM>. In other words, in one or more embodiments, the curvature of the inner surface <NUM> of each seal strip <NUM> may match a curvature of an imaginary cylinder with a diameter equal to the diameter <NUM> of the inner surface <NUM> of the shell <NUM> minus a radial width of the seal strip <NUM>. Further, the inner surface <NUM> of each of the first plurality of seal strips <NUM> may be spaced from the outer diameter <NUM> of a closest tube <NUM> of the plurality of axially extending tubes <NUM> by a distance <NUM>. The distance <NUM> between the inner surface <NUM> of the seal strips <NUM> and the outer diameter <NUM> of the closest tube <NUM> may be equal to the distance <NUM> between the outer diameters <NUM> of two adjacent tubes <NUM>. Furthermore, the first plurality of seal strips <NUM> may be angled from the outer surface <NUM> to the inner surface <NUM> by an angle <NUM> from a line <NUM> orthogonal to the shell <NUM> in a direction of the first fluid flow <NUM>. For example, in one or more embodiments, each of the first plurality of seal strips <NUM>, which are disposed perpendicularly to the angled baffles <NUM>, may be angled by <NUM>°-<NUM>° from a line <NUM> that is orthogonal to the shell <NUM> such that the first fluid flow <NUM> contacts the seal strip at a <NUM>°-<NUM>° angle and deflects back towards the plurality of tubes <NUM>. Further, the first plurality of seal strips <NUM> may have a thickness <NUM>, and a larger thickness <NUM> may be used for a heat exchanger <NUM> with a larger diameter <NUM> of the inner surface <NUM> of the shell <NUM>.

Each of the first plurality of seal strips <NUM>, as described for some embodiments herein, may have a curved outer diameter with a curvature that is elliptical and/or wherein each of the first plurality of seal strips have a curved inner diameter with a curvature that is elliptical. In other embodiments, the seal strips <NUM> may be wider in regions where the bundle-to-shell gap is larger. As the grid layout of the holes through the baffles may not result in a circular pattern for the outermost holes, a seal strip that may vary in width may provide better sealing. In some embodiments, the width may be achieved by varying an elliptical curvature of each of the inner and outer diameters of the seal strips. In other embodiments, the width may be varied systematically, such as to match a profile gap or provide a consistent profile gap between the inner diameter of the seal strips to each of the respective tubes. Similarly, a depth of the seal strips may be varied. Thus, in various embodiments, each of the first plurality of seal strips may have a width, outer diameter minus inner diameter, that varies along a length, first end to second end, of the seal strip, and/or each of the first plurality of seal strips may have a depth, proximal side to distal side, that varies along the width or the length of the seal strip.

Additionally, in one or more embodiments, a number of the first plurality of seal strips <NUM> per <NUM>° rotation about the longitudinal axis <NUM> may be a multiple of a number of baffles per <NUM>° rotation about the longitudinal axis <NUM>. Further, a number of the first plurality of seal strips <NUM> disposed between a baffle <NUM> and a corresponding, successive baffle <NUM> that is a full <NUM>° rotation from the baffle <NUM> may be equal for all baffles <NUM> in the plurality of baffles <NUM>. For example, in one or more embodiments, there may be four baffles <NUM> per <NUM>° rotation about the longitudinal axis <NUM>, and there may be four of the first plurality of seal strips <NUM> per <NUM>° rotation about the longitudinal axis <NUM> such that there is one of the first plurality of seal strips <NUM> per baffle <NUM> per <NUM>° rotation about the longitudinal axis <NUM>. In other embodiments, there may be four baffles <NUM> per <NUM>° rotation about the longitudinal axis <NUM>, and there may be eight of the first plurality of seal strips <NUM> per <NUM>° rotation about the longitudinal axis <NUM> such that there are two of the first plurality of seal strips <NUM> per baffle <NUM> per <NUM>° rotation about the longitudinal axis <NUM>. The number of the first plurality of seal strips <NUM> per <NUM>° rotation about the longitudinal axis <NUM> may be dependent on the size of the inner surface <NUM> of the shell <NUM>, the number of the plurality of tubes <NUM> disposed within the heat exchanger, and the distance <NUM> between the outer diameters <NUM> of the plurality of tubes <NUM>. In one or more embodiments, there may be one of the first plurality of seal strips <NUM> disposed within the shell <NUM> for every eight to ten rows of the plurality of tubes <NUM> disposed within the heat exchanger <NUM>.

Furthermore, referring to <FIG>, in one or more embodiments, at least one of the first plurality of seal strips <NUM> may be coupled to a proximal side <NUM> of the baffle <NUM> and at least one of the first plurality of seal strips <NUM> may be coupled to a distal side <NUM> of the baffle <NUM>. Additionally, in one or more embodiments, each of the first plurality of seal strips <NUM> that is coupled to the distal side <NUM> of each of the plurality of baffles <NUM> may be offset rotationally about the longitudinal axis <NUM> of the shell <NUM> from each of the first plurality of seal strips <NUM> that is coupled to the proximal side <NUM> of each of the plurality of baffles <NUM>. In one or more embodiments, the rotationally offset seal strips <NUM> may follow a predetermined pattern along an entire length of the heat exchanger <NUM>. Further, while rotationally offset adjacent seal strips <NUM> are shown in <FIG>, in one or more embodiments, the adjacent seal strips <NUM> may be longitudinally aligned along an entire length of the heat exchanger. Additionally, in one or more embodiments, the first plurality of seal strips <NUM> may be formed of steel.

In yet other embodiments, the first plurality of seal strips <NUM> may be disposed such that each of the first plurality of seal strips <NUM> are substantially parallel (substantially parallel being +/- <NUM>° or another small manufacturing tolerance) to a longitudinal axis of the heat exchanger. When parallel to the longitudinal axis, each seal strip should be connected to a proximal baffle <NUM> and a longitudinally adjacent distal baffle <NUM>. As compared to the prior practice of including a hole for the seal strip in each baffle plate and using a single, long seal strip from one end of the exchanger to the other, it has been found that individual seal strips between longitudinally adjacent baffles provides for both better sealing and a reduced pressure drop. In some embodiments, the seal strips connected to longitudinally adjacent baffles may be circumferentially offset. For example, each of the plurality of baffles may be connected to at least two seal strips <NUM>, including a distal seal strip <NUM> connected to a distal side of a baffle, and a proximal seal strip <NUM> connected to a proximal side of the same baffle, where the proximal seal strip is circumferentially offset from the distal seal strip. In some embodiments, the circumferential offset may be at least <NUM>°, at least <NUM>°, or at least <NUM>°, but necessarily offset by less than the total number of degrees of the respective elliptical sector of the sector shaped baffle. The rotationally or circumferentially offset seal strips may thus include one, two or more seal strips connected to a proximal side of a baffle as well as one, two or more seal strips connected to a distal side of a baffle, where the number of seal strips connected to the distal and proximal sides may be equal in some sectors and unequal in others. In some embodiments, an equal number of seal strips may be coupled to each baffle of the plurality of baffles. In other embodiments, a seal strip may not be coupled to every baffle of the plurality of baffles. For instance, where four baffles are used per <NUM>° rotation, including quadrants A, B, C, and D, seal strips may only be used in quadrants A and C or B and D, for example; in other embodiments, seal strips may be used, for instance, every three quadrants (successively A, D, C, B, A. The number and placement of seal strips may depend upon the sealing and structural requirements of a particular heat exchanger.

Referring now to <FIG>, portions of heat exchangers <NUM> according to several embodiments of the present disclosure are shown. As discussed above with regard to <FIG>, in one or more embodiments, a heat exchanger <NUM> may include a plurality of elliptical sector-shaped baffles <NUM> and a first plurality of seal strips <NUM> disposed between the baffles <NUM>. The first plurality of seal strips <NUM> may each be disposed between a first baffle <NUM> and a corresponding, successive baffle <NUM> that is a full <NUM>° rotation from the first baffle <NUM>. Further, a first end <NUM> of each of the first plurality of seal strips <NUM> may be coupled to a distal side <NUM> of one of the plurality of baffles <NUM> between a proximal radial edge <NUM> and a distal radial edge <NUM>, and a second end <NUM> of each of the first plurality of seal strips <NUM> may be coupled to a proximal side <NUM> of another of the plurality of baffles <NUM> between the proximal radial edge <NUM> and the distal radial edge <NUM>. In one or more embodiments, the proximal radial edge <NUM> of each baffle <NUM> may be the radial edge of the baffle <NUM> that is closest to an inlet of a shell of the heat exchanger <NUM>, and the distal radial edge <NUM> of each baffle <NUM> may be the radial edge of the baffle <NUM> that is farthest from the inlet of the shell of the heat exchanger <NUM>. Similarly, in one or more embodiments, the proximal side <NUM> of each baffle <NUM> may be the side of the baffle <NUM> that is closest to the inlet of the shell of the heat exchanger <NUM>, and the distal side <NUM> may be the side of each baffle <NUM> that is farthest from the inlet of the shell of the heat exchanger <NUM>.

Referring to <FIG>, in one or more embodiments, each of the first plurality of seal strips <NUM> may be disposed orthogonal to both the distal side <NUM> of one baffle <NUM> and the proximal side <NUM> of another baffle <NUM>. In other embodiments, each of the plurality of seal strips <NUM> may be disposed at an angle (not shown) from orthogonal to the proximal side <NUM> of one baffle <NUM> and the distal side <NUM> of the other baffle <NUM>, and the angle may be from greater than <NUM>° up to <NUM>°.

Referring to <FIG> by way of example only, seal strips <NUM> may be connected between a first baffle <NUM> and a second baffle <NUM> in the same quadrant. Each of the plurality of seal strips may be disposed at an angle from orthogonal to the proximal side <NUM> of the first baffle <NUM>, and the angle may be from greater than <NUM>° up to <NUM>° in a direction defined from the distal radial edge <NUM> to the proximal radial edge <NUM> of the second baffle <NUM>. Further, as discussed above, in other embodiments, the angle may be one of from greater than <NUM>° up to <NUM>°, from <NUM>° up to <NUM>°, or from <NUM>° up to <NUM>°. Due to the possible leakage of a first fluid between consecutive baffles of the plurality of baffles <NUM>, the direction of the first fluid flow may vary slightly from the helical path formed by the plurality of baffles <NUM>. Further, due to this possible variance in the first fluid flow direction, the angle of the seal strips <NUM> may vary such that each of the first plurality of seal strips <NUM> may be orthogonal to the helical first fluid flow direction.

Referring to <FIG> by way of example only, seal strips <NUM> may be connected between a first baffle <NUM> in a first quadrant and a second baffle <NUM> in an adjacent quadrant. Each of the plurality of seal strips may be disposed at an angle from orthogonal to the proximal side <NUM> of the first baffle <NUM>, and the angle may be from greater than <NUM>° up to <NUM>° in a direction defined from the distal radial edge <NUM> to the proximal radial edge <NUM> of the second baffle <NUM>. Further, as discussed above, in other embodiments, the angle may be one of from greater than <NUM>° up to <NUM>°, from <NUM>° up to <NUM>°, or from <NUM>° up to <NUM>° in a direction defined from the distal radial edge <NUM> to the proximal radial edge <NUM> of the second baffle <NUM>. Due to the possible leakage of a first fluid between consecutive baffles of the plurality of baffles <NUM>, the direction of the first fluid flow may vary slightly from the helical path formed by the plurality of baffles <NUM>. Further, due to this possible variance in the first fluid flow direction, the angle of the seal strips <NUM> may vary such that each of the first plurality of seal strips <NUM> may be orthogonal to the helical first fluid flow direction.

In some embodiments, some seal strips <NUM> may be connected between baffles <NUM> in the same quadrant, as illustrated in <FIG>, while other seal strips <NUM> may be connected between baffles <NUM> in adjacent quadrants, as illustrated in <FIG>.

While embodiments shown in <FIG> may include a plurality of seal strips <NUM> that are all disposed at the same angle between one baffle <NUM> and another baffle <NUM>, referring to <FIG>, in one or more embodiments, the seal strips <NUM> may be disposed at different angles (not shown) within the heat exchanger. In other words, referring to <FIG>, in one or more embodiments, one seal strip 650a of the plurality of seal strips <NUM> may be disposed orthogonal to both the distal side <NUM> of one baffle <NUM> and the proximal side <NUM> of another baffle <NUM>, and another seal strip 650b of the plurality of seal strips <NUM> may be disposed at an angle from orthogonal to the proximal side <NUM> of one baffle <NUM> and the distal side <NUM> of the other baffle <NUM> in which the angle may be from greater than <NUM>° up to <NUM>°. Thus, while in one or more embodiments, all of the seal strips <NUM> may be disposed between baffles with the same angular disposition, in other embodiments, a combination of seal strips <NUM> of different angular dispositions may be used. Further, while in one or more embodiments, seal strips 650a of a first angular disposition may be used between the baffles <NUM> of the first several rotations about the longitudinal axis and seal strips 650b of a second angular disposition may be used between the baffles <NUM> of the remaining rotations about the longitudinal axis, in other embodiments, different patterns of seal strips 650a of a first angular disposition and seal strips 650b of a second angular disposition may be used. Furthermore, in one or more embodiments, seal strips of more than two angular dispositions may be used throughout the heat exchanger in different patterns. In some embodiments, both the angular dispositions of the seal strips and the quadrants between which the seal strips are arranged may vary within a heat exchanger.

Referring now to <FIG>, a portion of a heat exchanger <NUM> according to one or more embodiments of the present disclosure is shown. In one or more embodiments, a heat exchanger <NUM> may include a shell (not shown) through which a first fluid is passed, a plurality of axially extending tubes <NUM> through which a second fluid is passed, a plurality of elliptical sector-shaped baffles <NUM>, and a first plurality of seal strips <NUM> disposed between the baffles <NUM>. The shell may include an inlet (not shown) and an outlet (not shown) between which the first fluid may pass within the shell. Further, the plurality of tubes <NUM>, the plurality of baffles <NUM>, and the first plurality of seal strips <NUM> may be disposed within the shell.

Referring to <FIG>, similar to heat exchangers discussed above, in one or more embodiments, the plurality of baffles <NUM> may be disposed such that successive baffles <NUM> are positioned at an angle from a line that is normal to a longitudinal axis (not shown) of the shell. In one or more embodiments, the baffles <NUM> may be coupled about the longitudinal axis, and the successive baffles <NUM> may be rotationally and longitudinally offset from each other such that a helical pattern is formed. The rotational offset between successive baffles <NUM> may be such that at least a proximal radial edge <NUM> of one baffle <NUM> overlaps a distal radial edge <NUM> of an adjacent baffle <NUM> in a longitudinal direction. In one or more embodiments, the proximal radial edge <NUM> of each baffle <NUM> may be the radial edge of the baffle <NUM> that is closest to the inlet of the shell of the heat exchanger <NUM>, and the distal radial edge <NUM> of each baffle <NUM> may be the radial edge of the baffle <NUM> that is farthest from the inlet of the shell of the heat exchanger <NUM>. Further, as discussed above, in one or more embodiments, there may be an equal number of baffles <NUM> per <NUM>° rotation about the longitudinal axis about which the baffles <NUM> are disposed.

Still referring to <FIG>, in one or more embodiments, the baffles <NUM> may be elliptical sector-shaped. Each of the baffles <NUM> may have an outer circumferential edge <NUM>, and each outer circumferential edge <NUM> may be spaced apart from the outer circumferential edge <NUM> of an adjacent baffle <NUM>. Each of the baffles <NUM> may also include the proximal radial edge <NUM> at one end of the outer circumferential edge <NUM> and the distal radial edge <NUM> at the other end of the outer circumferential edge <NUM> such that the elliptical sector-shaped baffles <NUM> are defined by the outer circumferential edge <NUM>, the proximal radial edge <NUM>, and the distal radial edge <NUM>. Furthermore, each of the baffles <NUM> may have a proximal side <NUM> and a distal side <NUM> that are opposite of each other as well as a plurality of spaced apart holes (not shown) that extend through the baffles <NUM> from the proximal side <NUM> to the distal side <NUM>. In one or more embodiments, the proximal side <NUM> of each baffle <NUM> may be the side of the baffle <NUM> that is closest to the inlet of the shell of the heat exchanger <NUM>, and the distal side <NUM> may be the side of each baffle <NUM> that is farthest from the inlet of the shell of the heat exchanger <NUM>. Further, in one or more embodiments, one tube <NUM> of the plurality of axially extending tubes <NUM> may pass through holes in the baffles <NUM>. Therefore, as discussed above, the plurality of tubes <NUM> may extend axially along an entire length of a heat exchanger <NUM>, and each of the tubes <NUM> may be supported by multiple baffles <NUM> spaced equally along a length of the tube <NUM>. Furthermore, a distance between outer diameters of each of the tubes <NUM> that are disposed in each of the holes may be consistent across the entirety of the plurality of tubes <NUM>.

Further, referring to <FIG>, in one or more embodiments, a first plurality of seal strips <NUM> may each be disposed between a first baffle <NUM> and a corresponding, successive baffle <NUM> that is a full <NUM>° rotation from the first baffle <NUM>. Furthermore, each of the first plurality of seal strips <NUM> may be disposed radially between the plurality of tubes <NUM> and a diameter of an inner surface of the shell. As discussed above, in one or more embodiments, each of the first plurality of seal strips <NUM> may be coupled to each of the first baffle <NUM> and the corresponding, successive baffle <NUM>. In one or more embodiments, the first plurality of seal strips <NUM> may be disposed such that each of the first plurality of seal strips <NUM> are orthogonal to the helical first fluid flow direction within the shell of the heat exchanger <NUM>. Further, in one or more embodiments, a first end <NUM> of each of the first plurality of seal strips <NUM> may be coupled to the distal side <NUM> of one of the plurality of baffles <NUM> between the proximal radial edge <NUM> and the distal radial edge <NUM>, and a second end <NUM> of each of the first plurality of seal strips <NUM> may be coupled to the proximal side <NUM> of another of the plurality of baffles <NUM> between the proximal radial edge <NUM> and the distal radial edge <NUM>.

As discussed above, in one or more embodiments, each of the first plurality of seal strips <NUM> may be disposed orthogonal to both the distal side <NUM> of one baffle <NUM> and the proximal side <NUM> of another baffle <NUM>. Further, in other embodiments, each of the plurality of seal strips <NUM> may be disposed at an angle (not shown) from orthogonal to the proximal side <NUM> of one baffle <NUM> and the distal side <NUM> of the other baffle <NUM>; the angle may be from greater than <NUM>° up to <NUM>°. In further embodiments, the angle may be one of from greater than <NUM>° up to <NUM>°, from <NUM>° up to <NUM>°, from <NUM>° up to <NUM>°, or from <NUM>° up to <NUM>°. Due to the possible leakage of a first fluid between consecutive baffles of the plurality of baffles <NUM>, the direction of the first fluid flow may vary slightly from the helical path formed by the plurality of baffles <NUM>. Further, due to this possible variance in the first fluid flow direction, the angle of the seal strips <NUM> may vary such that each of the first plurality of seal strips <NUM> may be orthogonal to the helical first fluid flow direction. The baffles <NUM> may be arranged in quadrants. In some embodiments, seal strips <NUM> may be connected between baffles <NUM> located in the same quadrant. In some embodiments, seal strips <NUM> may be connected between baffles <NUM> located in adjacent quadrants. In some embodiments, seal strips <NUM> may be connected between both baffles <NUM> located in the same quadrant and baffles <NUM> located in adjacent quadrants.

Furthermore, referring to <FIG>, in one or more embodiments, each of the first plurality of seal strips <NUM> may have a substantially similar structure to the first plurality of seal strips as described above with regard to <FIG> and <FIG>. Therefore, the first plurality of seal strips <NUM> may have a curved inner surface and a curved outer surface. In one or more embodiments, the curved outer surface of each seal strip <NUM> may be disposed substantially proximate the inner surface of the shell. Further, in one or more embodiments, the curved outer surface of one or more of the seal strips <NUM> may contact the inner surface of the shell. Additionally, a curvature of the curved outer surface of the seal strips <NUM> may be elliptical in shape and may match a curvature of the inner surface of the shell.

Furthermore, in one or more embodiments, a curvature of the curved inner surface of each of the first plurality of seal strips <NUM> may be elliptical in shape and the curvature of the inner surface may be different than the curvature of the outer surface of each of the first plurality of seal strips <NUM>. In other words, in one or more embodiments, the curvature of the inner surface of each seal strip <NUM> may match a curvature of an imaginary cylinder with a diameter equal to the diameter of the inner surface of the shell minus a radial width of the seal strip <NUM>. Further, the inner surface of each of the first plurality of seal strips <NUM> may be spaced from the outer diameter of a closest tube <NUM> of the plurality of axially extending tubes <NUM> by a distance. The distance between the inner surface of the seal strips <NUM> and the outer diameter of the closest tube <NUM> may be equal to the distance between the outer diameters of two adjacent tubes <NUM>. Furthermore, in one or more embodiments, the first plurality of seal strips <NUM> may be angled from the outer surface to the inner surface by an angle from a line orthogonal to the shell in a direction of the first fluid flow. Further, the first plurality of seal strips <NUM> may have a thickness that varies depending on the diameter of the inner surface of the shell.

Still referring to <FIG>, in one or more embodiments, at least one of the first plurality of seal strips <NUM> may be coupled to a proximal side <NUM> of the baffle <NUM> and at least one of the first plurality of seal strips <NUM> may be coupled to a distal side <NUM> of the baffle <NUM>. Additionally, in one or more embodiments, each of the first plurality of seal strips <NUM> that is coupled to the distal side <NUM> of each of the plurality of baffles <NUM> may be longitudinally aligned with each of the first plurality of seal strips <NUM> that is coupled to the proximal side <NUM> of each of the plurality of baffles <NUM> in a direction that is parallel to the longitudinal axis of the shell of the heat exchanger <NUM>. As discussed above, in one or more embodiments, a number of the first plurality of seal strips <NUM> disposed between a baffle <NUM> and a corresponding, successive baffle <NUM> that is a full <NUM>° rotation from the baffle <NUM> may be equal for all baffles <NUM> in the plurality of baffles <NUM>, and thus, a number of the first plurality of seal strips <NUM> per <NUM>° rotation about the longitudinal axis may be a multiple of the number of baffles <NUM> per <NUM>° rotation about the longitudinal axis.

Referring now to <FIG>, a portion of a heat exchanger <NUM> according to one or more embodiments of the present disclosure is shown. In one or more embodiments, a heat exchanger <NUM> may include a shell (not shown) through which a first fluid is passed, a plurality of axially extending tubes <NUM> through which a second fluid is passed, a plurality of elliptical sector-shaped baffles <NUM>, a first plurality of seal strips <NUM> disposed between the baffles <NUM>, and a second plurality of seal strips <NUM> disposed between the baffles <NUM>. The shell may include an inlet (not shown) and an outlet (not shown) between which the first fluid may pass within the shell. Further, the plurality of tubes <NUM>, the plurality of baffles <NUM>, the first plurality of seal strips <NUM>, and the second plurality of seal strips <NUM> may be disposed within the shell.

Still referring to <FIG>, similar to heat exchangers discussed above, in one or more embodiments, the plurality of baffles <NUM> may be disposed such that successive baffles <NUM> are positioned at an angle from a line that is normal to a longitudinal axis (not shown) of the shell. In one or more embodiments, the baffles <NUM> may be coupled about the longitudinal axis, and the successive baffles <NUM> may be rotationally and longitudinally offset from each other such that a helical pattern is formed. The rotational offset between successive baffles <NUM> may be such that at least a proximal radial edge <NUM> of one baffle <NUM> overlaps a distal radial edge <NUM> of an adjacent baffle <NUM> in a longitudinal direction. Further, the longitudinal offset of the overlapping proximal radial edge <NUM> and distal radial edge <NUM> between successive baffles <NUM> may create a gap <NUM> between the proximal radial edge <NUM> and the distal radial edge <NUM> through which a first fluid flow may be able to travel. In one or more embodiments, the proximal radial edge <NUM> of each baffle <NUM> may be the radial edge of the baffle <NUM> that is closest to the inlet of the shell of the heat exchanger <NUM>, and the distal radial edge <NUM> of each baffle <NUM> may be the radial edge of the baffle <NUM> that is farthest from the inlet of the shell of the heat exchanger <NUM>. Further, as discussed above, in one or more embodiments, there may be an equal number of baffles <NUM> per <NUM>° rotation about the longitudinal axis about which the baffles <NUM> are disposed.

Further, referring to <FIG>, in one or more embodiments, the baffles <NUM> may be elliptical sector-shaped. Each of the baffles <NUM> may have an outer circumferential edge <NUM>, and each outer circumferential edge <NUM> may be spaced apart from the outer circumferential edge <NUM> of an adjacent baffle <NUM>. Each of the baffles <NUM> may also include the proximal radial edge <NUM> at one end of the outer circumferential edge <NUM> and the distal radial edge <NUM> at the other end of the outer circumferential edge <NUM> such that the elliptical sector-shaped baffles <NUM> are defined by the outer circumferential edge <NUM>, the proximal radial edge <NUM>, and the distal radial edge <NUM>. Furthermore, each of the baffles <NUM> may have a proximal side <NUM> and a distal side <NUM> that are opposite of each other as well as a plurality of spaced apart holes (not shown) that extend through the baffles <NUM> from the proximal side <NUM> to the distal side <NUM>. In one or more embodiments, the proximal side <NUM> of each baffle <NUM> may be the side of the baffle <NUM> that is closest to the inlet of the shell of the heat exchanger <NUM>, and the distal side <NUM> may be the side of each baffle <NUM> that is farthest from the inlet of the shell of the heat exchanger <NUM>. Further, in one or more embodiments, one tube <NUM> of the plurality of axially extending tubes <NUM> may pass through each of the holes in the baffles <NUM>. Therefore, as discussed above, the plurality of tubes <NUM> may extend axially along an entire length of a heat exchanger <NUM>, and each of the tubes <NUM> may be supported by multiple baffles <NUM> spaced equally along a length of the tube <NUM>. Furthermore, a distance between outer diameters of each of the tubes <NUM> that are disposed in each of the holes may be consistent across the entirety of the plurality of tubes <NUM>.

Furthermore, referring to <FIG>, in one or more embodiments, a first plurality of seal strips <NUM> may each be disposed between a first baffle <NUM> and a corresponding, successive baffle <NUM> that is a full <NUM>° rotation from the first baffle <NUM>. Furthermore, each of the first plurality of seal strips <NUM> may be disposed radially between the plurality of tubes <NUM> and a diameter of an inner surface of the shell. As discussed above, in one or more embodiments, each of the first plurality of seal strips <NUM> may be coupled to each of the first baffle <NUM> and the corresponding, successive baffle <NUM>. In one or more embodiments, the first plurality of seal strips <NUM> may be disposed such that each of the first plurality of seal strips <NUM> is orthogonal to the helical first fluid flow direction within the shell of the heat exchanger <NUM>. Further, in one or more embodiments, a first end <NUM> of each of the first plurality of seal strips <NUM> is coupled to the distal side <NUM> of one of the plurality of baffles <NUM> between the proximal radial edge <NUM> and the distal radial edge <NUM>, and a second end <NUM> of each of the first plurality of seal strips <NUM> is coupled to the proximal side <NUM> of another of the plurality of baffles <NUM> between the proximal radial edge <NUM> and the distal radial edge <NUM>.

As discussed above, in one or more embodiments, each of the first plurality of seal strips <NUM> may be disposed orthogonal to both the distal side <NUM> of one baffle <NUM> and the proximal side <NUM> of another baffle <NUM>. Further, in other embodiments, each of the plurality of seal strips <NUM> may be disposed at an angle (not shown) from orthogonal to the proximal side <NUM> of one baffle <NUM> and the distal side <NUM> of another baffle <NUM>; the angle may be from greater than <NUM>° up to <NUM>°. In further embodiments, the angle may be one of from greater than <NUM>° up to <NUM>°, from <NUM>° up to <NUM>°, from <NUM>° up to <NUM>°, or from <NUM>° up to <NUM>°. Due to the possible leakage of a first fluid between consecutive baffles of the plurality of baffles <NUM>, the direction of the first fluid flow may vary slightly from the helical path formed by the plurality of baffles <NUM>. Further, due to this possible variance in the first fluid flow direction, the angle of the seal strips <NUM> may vary such that each of the first plurality of seal strips <NUM> may be orthogonal to the helical first fluid flow direction.

The baffles <NUM> may be arranged in quadrants. In some embodiments, seal strips <NUM> may be connected between baffles <NUM> located in the same quadrant. In some embodiments, seal strips <NUM> may be connected between baffles <NUM> located in adjacent quadrants. In some embodiments, seal strips <NUM> may be connected between both baffles <NUM> located in the same quadrant and baffles <NUM> located in adjacent quadrants.

Additionally, referring to <FIG>, in one or more embodiments, each of the first plurality of seal strips <NUM> may have a substantially similar structure to the first plurality of seal strips as described above with regard to <FIG>. Therefore, the first plurality of seal strips <NUM> may have a curved inner surface and a curved outer surface. Further, in one or more embodiments, at least one of the first plurality of seal strips <NUM> may be coupled to a proximal side <NUM> of the baffle <NUM> and at least one of the first plurality of seal strips <NUM> may be coupled to a distal side <NUM> of the baffle <NUM>. Additionally, in one or more embodiments, each of the first plurality of seal strips <NUM> that is coupled to the distal side <NUM> of each of the plurality of baffles <NUM> may be longitudinally aligned with each of the first plurality of seal strips <NUM> that is coupled to the proximal side <NUM> of each of the plurality of baffles <NUM> in a direction that is parallel to the longitudinal axis of the shell of the heat exchanger <NUM>. Further, as discussed above, in one or more embodiments, a number of the first plurality of seal strips <NUM> disposed between a baffle <NUM> and a corresponding, successive baffle <NUM> that is a full <NUM>° rotation from the baffle <NUM> may be equal for all baffles <NUM> in the plurality of baffles <NUM>, and thus, a number of the first plurality of seal strips <NUM> per <NUM>° rotation about the longitudinal axis may be a multiple of the number of baffles per <NUM>° rotation about the longitudinal axis.

Still referring to <FIG>, each of a second plurality of seal strips <NUM> may be disposed between one of the baffles <NUM> and a successive baffle <NUM> within the gap <NUM> formed between the proximal side <NUM> of the one of the baffles <NUM> and the distal side <NUM> of the successive baffle <NUM> in a region in which the distal radial edge <NUM> of the one of the baffles <NUM> overlaps with the proximal radial edge <NUM> of the successive baffle <NUM>. Further, each of the second plurality of seal strips <NUM> may be coupled to the baffles <NUM> in a direction that is parallel to the longitudinal axis of the shell of the heat exchanger <NUM>, and the second plurality of seal strips <NUM> may be disposed radially between the shell and the plurality of tubes <NUM>. Furthermore, each of the second plurality of seal strips <NUM> may have a first end <NUM> that may be coupled proximate to the proximal radial edge <NUM> of the distal side <NUM> of one of the plurality of baffles <NUM> and a second end <NUM> that may be coupled proximate to the distal radial edge <NUM> of the proximal side <NUM> of another of the plurality of baffles. Additionally, in one or more embodiments, each of the second plurality of seal strips <NUM> may be trapezoidal-shaped with an inner surface <NUM> and an outer surface <NUM>. The inner surface <NUM> of each of the second plurality of seal strips <NUM> may be spaced from an outer diameter of a closest tube <NUM> of the plurality of axially extending tubes <NUM> by a distance that may be equal to the distance between outer diameters of two adjacent tubes <NUM> of the plurality of axially extending tubes <NUM>. Further, in one or more embodiments, a number of the second plurality of seal strips <NUM> disposed between a baffle <NUM> and a successive baffle <NUM> in the gap <NUM> formed by the region of overlap between the baffles <NUM> may be equal to the number of baffles per <NUM>° rotation about the longitudinal axis.

Referring now to <FIG>, a heat exchanger <NUM> according to one or more embodiments of the present disclosure is shown. <FIG> illustrates a heat exchanger having a double helix flow pattern, which may include strips as described above between the helices. While the strips are not illustrated for ease of understanding the flow pattern, the description below is inclusive of the strips and illustrative of how the strips may be incorporated into a heat exchanger having multiple helical flow paths.

In one or more embodiments, a heat exchanger <NUM> may include a shell <NUM> through which a first fluid is passed, a plurality of axially extending tubes (not shown) through which a second fluid is passed, a first plurality of elliptical sector-shaped baffles <NUM>, a second plurality of elliptical sector-shaped baffles <NUM> longitudinally offset from the first plurality of baffles <NUM>, a first plurality of seal strips (not shown) each disposed between a first baffle <NUM> and a second baffle <NUM>, and a second plurality of seal strips <NUM> disposed between the baffles <NUM>. The shell may include an inlet <NUM> and an outlet (not shown) between which the first fluid may pass within the shell. Further, the plurality of tubes, the first plurality of baffles <NUM>, the second plurality of baffles <NUM>, the first plurality of seal strips, and the second plurality of seal strips may be disposed within the shell <NUM>.

Still referring to <FIG>, similar to heat exchangers discussed above, in one or more embodiments, the first plurality of baffles <NUM> may be disposed such that successive first baffles <NUM> are positioned at an angle from a line that is normal to a longitudinal axis <NUM> of the shell <NUM>. In one or more embodiments, the first plurality of baffles <NUM> may be coupled about the longitudinal axis <NUM>, and the successive first baffles <NUM> may be rotationally and longitudinally offset from each other such that a helical pattern is formed. The rotational offset between successive first baffles <NUM> may be such that at least a first radial edge (not shown) of one first baffle <NUM> overlaps a second radial edge (not shown) of an adjacent first baffle <NUM> in a longitudinal direction. Further, the longitudinal offset of the overlapping first radial edge and second radial edge between successive first baffles <NUM> may create a gap between the first radial edge and the second radial edge through which a first fluid flow may be able to travel. Further, as discussed above, in one or more embodiments, there may be an equal number of the first plurality of baffles <NUM> per <NUM>° rotation about the longitudinal axis <NUM> about which the first plurality of baffles <NUM> are disposed.

Similarly, the second plurality of baffles <NUM> may be disposed such that successive second baffles <NUM> are positioned at an angle from a line that is normal to the longitudinal axis <NUM> of the shell <NUM>. In one or more embodiments, the second plurality of baffles <NUM> may be coupled about the longitudinal axis <NUM>, and the successive second baffles <NUM> may be rotationally and longitudinally offset from each other such that a helical pattern substantially identical to the helical pattern of the first plurality of baffles <NUM> is formed. The rotational offset between successive second baffles <NUM> may be such that at least a first radial edge (not shown) of one second baffle <NUM> overlaps a second radial edge (not shown) of an adjacent second baffle <NUM> in a longitudinal direction. Further, the longitudinal offset of the overlapping first radial edge and second radial edge between successive second baffles <NUM> may be the same as the longitudinal offset of the first baffles <NUM> and may create the same gap between the first radial edge and the second radial edge through which a first fluid flow may be able to travel. Further, as discussed above, in one or more embodiments, there may be an equal number of the second plurality of baffles <NUM> per <NUM>° rotation about the longitudinal axis <NUM> about which the second plurality of baffles <NUM> are disposed. Additionally, the second plurality of baffles <NUM> may be longitudinally offset from the first plurality of baffles <NUM> such that the flow path between successive rotations of first baffles <NUM> is separated into two separate flow paths. In one or more embodiments, the second plurality of baffles may be longitudinally offset from the first plurality of baffles by half of a distance between first baffles <NUM> that are a <NUM>° rotation from each other.

Further, in one or more embodiments, each of the first plurality of baffles <NUM> and the second plurality of baffles <NUM> may be elliptical sector-shaped. Each of the baffles <NUM>, <NUM> may have an outer circumferential edge (not shown), and each outer circumferential edge may be spaced apart from the outer circumferential edge of an adjacent baffle <NUM>, <NUM>. Each of the baffles <NUM>, <NUM> may also include the first radial edge at one end of the outer circumferential edge and the second radial edge at the other end of the outer circumferential edge such that the elliptical sector-shaped baffles <NUM>, <NUM> are defined by the outer circumferential edge, the first radial edge, and the second radial edge. Furthermore, each of the baffles <NUM>, <NUM> may have a first side (not shown) and a second side (not shown) that are opposite of each other as well as a plurality of spaced apart holes (not shown) that extend through the baffles <NUM>, <NUM> from the first side to the second side. In one or more embodiments, each first baffle <NUM> may be aligned with an adjacent second baffle <NUM> such that the holes of each first baffle <NUM> aligns with the holes of the adjacent second baffle <NUM> and one tube of the plurality of axially extending tubes may pass through each of the holes in the baffles <NUM>, <NUM>. Therefore, as discussed above, the plurality of tubes may extend axially along an entire length of a heat exchanger <NUM>, and each of the tubes may be supported by multiple baffles of each of the first plurality of baffles <NUM> and the second plurality of baffles <NUM>. Furthermore, a distance between outer diameters of each of the tubes that are disposed in each of the holes may be consistent across the entirety of the plurality of tubes.

Furthermore, in one or more embodiments, a first plurality of seal strips may each be disposed between a first baffle of the first plurality of baffles <NUM> and a corresponding, adjacent baffle of the second plurality of baffles <NUM> that is aligned with the first baffle of the first plurality of baffles <NUM>. In other words, each of the first plurality of seal strips may be coupled between one of the first side and the second side of one of the first plurality of baffles <NUM> and the corresponding first side or second side of one of the second plurality of baffles <NUM>. Additionally, each of the first plurality of seal strips may be disposed within the shell <NUM> of the heat exchanger <NUM> as described above with regard to other embodiments, and each of the first plurality of seal strips may have a substantially similar structure to the first plurality of seal strips as described above with regard to other embodiments. Further, each of a second plurality of seal strips may be disposed between one of the first plurality of baffles <NUM> and a successive baffle of the first plurality of baffles <NUM> and between one of the second plurality of baffles <NUM> and a successive baffle of the second plurality of baffles <NUM> within the gaps formed between the first side of the one of the baffles <NUM>, <NUM> and the second side of the successive baffle <NUM>, <NUM> in a region in which the first radial edge of the one of the baffles <NUM>, <NUM> overlaps with the second radial edge of the successive baffle <NUM>, <NUM>. Further, each of the second plurality of seal strips may be disposed within the shell <NUM> of the heat exchanger <NUM> as described above with regard to other embodiments, and each of the second plurality of seal strips may have a substantially similar structure to the second plurality of seal strips as described above with regard to other embodiments.

Embodiments disclosed herein are also directed toward methods of assembling of a heat exchanger. The method may include providing a center rod having a longitudinal axis and mounting a plurality of elliptical sector-shaped baffles to the center rod at an angle to the longitudinal axis of the center rod such that a helical pattern is formed by the plurality of baffles. Each of the plurality of baffles may include: an outer circumferential edge longitudinally spaced apart from the outer circumferential edge positions of the rest of the plurality of baffles; a proximal radial edge spaced from a distal radial edge; a proximal side opposite from a distal side; and a plurality of spaced apart holes. A plurality of axially extending tubes may be disposed into the plurality of spaced apart holes of each of the plurality of baffles, wherein the plurality of axially extending tubes are configured to carry a second fluid.

The method may further include coupling a first plurality of seal strips having a first end and a second end radially between the shell and the plurality of axially extending tubes. Coupling of the first plurality of seal strips may include: coupling the first end of each of the first plurality of seal strips to the distal side of one of the plurality of baffles; and coupling the second end of each of the first plurality of seal strips to the proximal side of another of the plurality of baffles. Each of the first plurality of seal strips is disposed either: orthogonal to both the distal side of the one of the plurality of baffles and the proximal side of the other of the plurality of baffles; or at an angle from orthogonal to the proximal side of one of the plurality of baffles and the distal side of another of the plurality of baffles, wherein the angle is from greater than <NUM>° up to <NUM>°. The assembled center rod, plurality of baffles, plurality of axially extending tubes, and first plurality of seal strips may then be disposed within a shell that is configured to receive a first fluid.

The coupled first plurality of seal strips have an inner diameter and an outer diameter. Coupling the first plurality of seal strips may include angling the coupled first plurality of seal strips from the outer diameter to the inner diameter by an angle from orthogonal to the shell in the direction defined from the proximal radial edge to the distal radial edge of the one of the plurality of baffles.

Coupling the first plurality of seal strips may further include spacing an inner diameter of each of the first plurality of seal strips from an outer diameter of a closest tube of the plurality of axially extending tubes by a distance that is equal to a distance between outer diameters of two adjacent tubes of the plurality of axially extending tubes. Coupling the first plurality of seal strips may also include rotationally offsetting each of the first plurality of seal strips coupled to the distal side of each of the plurality of baffles from each of the plurality of seal strips coupled to the proximal side of each of the plurality of baffles.

The method of assembly may also include in some embodiments coupling a second plurality of seal strips having a first end and a second end radially between the shell and the plurality of axially extending tubes. Coupling the second plurality of seal strips may include: coupling the first end of each of the second plurality of seal strips to the distal radial edge of the distal side of one of the plurality of baffles; and coupling the second end of each of the second plurality of seal strips to the proximal radial edge of the proximate side of another of the plurality of baffles, wherein each of the second plurality of seal strips extends parallel to the longitudinal axis of the shell.

The heat exchanger according to one or more embodiments of the present disclosure that has seal strips disposed orthogonal to each of a plurality of baffles such that the seal strips are orthogonal to a direction of flow of a first fluid provides many benefits over conventional heat exchangers and other helically-baffled heat exchangers. For example, seal strips disposed orthogonal to each of the baffles may allow for a lower pressure drop over the entire length of the heat exchanger than heat exchangers that include seal strips that are disposed parallel to a longitudinal axis of the heat exchanger. Further, by way of example, seal strips disposed orthogonal to a direction of the first fluid flow and at an angle such that the first fluid flow is directed back towards a plurality of tubes carrying a second fluid may allow for less of the first fluid to bypass the plurality of tubes than seal strips that are disposed parallel to a longitudinal axis of the heat exchanger. Furthermore, by way of example, in one or more embodiments, radially offsetting the plurality of seal strips along a length of the heat exchanger may allow for providing local heat transfer enhancement to a greater number of the plurality of tubes. Additionally, by way of example, a second plurality of seal strips disposed adjacent to first and second radial edges of the baffles may allow for less of the first fluid to leave the helical flow path by leaking around the overlapping baffles. Therefore, the heat exchanger according to one or more embodiments may allow for an enhanced efficiency of heat transfer in addition to a lower cost of manufacturing and a lower cost of maintenance compared to that of conventional heat exchangers and other helically-baffled heat exchangers.

Several surprising results are noted with respect to embodiments of the present disclosure. First, experiments have shown that conventional seal strips, not arranged as disclosed herein, have little direct effect on heat transfer. In this way, they do not significantly improve the efficiency of heat exchangers to which they are added. In fact, these experiments have shown that conventional seal strips can cause significant pressure drops within heat exchangers, when compared to the same heat exchangers with no seal strips. The pressure drop may reduce the efficiency of heat transfer in the heat exchanger. This result is unexpected because prior art teaches that any seal strip improves the performance of a heat exchanger by preventing fluid from bypassing the tube bundle. Current findings show however that the seal strips arranged according to embodiments herein may improve the performance of a heat exchanger.

Referring now to <FIG>, heat exchanger performance of three heat exchangers is compared: (<NUM>) a heat exchanger with no seal strips (triangles), (<NUM>) a heat exchanger including four longitudinal seal strips extending the length of the exchanger disposed through respective through-holes in each baffle (squares), and (<NUM>) a heat exchanger including angled seal strips, where the seal strips direct flow in a manner to encourage helical flow of fluid through the heat exchanger (circles). The experimental data is shown including the Reynolds number on the bottom axis, a pressure-drop conversion ratio on the left axis, and a Peclet number on the right axis. As shown, for the given Reynolds number of the fluid flow, the pressure-drop conversion ratio and Peclet numbers improve for the seal strips arranged according to embodiments herein, indicating a higher efficiency of conversion of pressure drop to heat transfer.

Second, experiments have shown that seal strips connected such that they oppose fluid flow, i.e. connected in reverse from what is taught herein, can significantly reduce heat transfer. In some experiments, these seal strips reduced heat transfer as much as <NUM>% relative to heat exchangers with no seal strips. This is surprising because sealing of any type is expected to prevent bypassing and thereby improve heat transfer. These results demonstrate however, that not only must bypassing be prevented, but significant pressure drops also must be avoided, in order to improve the heat transfer in a heat exchanger. Accordingly, the specific arrangement and orientation of seal strips taught herein is important in achieving improved heat transfer.

Third, experiments have shown that seal strips connected as disclosed herein can increase heat transfer without causing significant pressure drops. These seal strips are connected to encourage helical flow of fluid through the heat exchanger. This is unexpected because prior art teaches that any sealing causes a pressure drop penalty of approximately <NUM>%-<NUM>%. Therefore, the results of the present disclosure are more significantly positive than would have been expected based on the prior art, because they provide improved heat transfer without a corresponding increased pressure drop.

Claim 1:
A heat exchanger (<NUM>) comprising:
a shell (<NUM>) having a longitudinal axis (<NUM>) and configured to receive a first fluid (<NUM>);
a plurality of baffles (<NUM>) each mounted in the shell (<NUM>) at a helix angle HB to guide a first fluid flow (<NUM>) into a helical pattern (<NUM>) through the shell (<NUM>), wherein each of the plurality of baffles (<NUM>) comprises:
an outer circumferential edge (<NUM>) longitudinally spaced apart from the outer circumferential edge (<NUM>) positions of the rest of the plurality of baffles (<NUM>);
a proximal radial edge (<NUM>) spaced from a distal radial edge (<NUM>);
a proximal side (<NUM>) opposite from a distal side (<NUM>); and
a plurality of spaced apart holes (<NUM>) configured to be traversed by a plurality of axially extending tubes (<NUM>) configured to carry a second fluid (<NUM>); and
characterized by a first plurality of seal strips (<NUM>), each having a first end (<NUM>) and a second end (<NUM>), radially disposed between the shell (<NUM>) and the plurality of axially extending tubes (<NUM>) and each respectively positioned between any two adjacent baffles (<NUM>),
wherein each of the first plurality of seal strips (<NUM>) is disposed to have the first end (<NUM>) of each seal strip (<NUM>) proximate to the distal side (<NUM>) of a respective baffle (<NUM>) and the second end (<NUM>) of each seal strip (<NUM>) proximate to the proximal side (<NUM>) of a respective baffle (<NUM>) at a helix angle Hs that is greater than <NUM>° and less than the baffle helix angle HB,
where the helix angles HB and Hs are defined as the angle of the respective baffle (<NUM>) or seal strip (<NUM>) relative to the longitudinal axis (<NUM>) of the shell (<NUM>), and
wherein each of the first plurality of seal strips (<NUM>) have an angle (<NUM>) greater than <NUM>° up to <NUM>° formed between each of the first plurality of seal strips (<NUM>) and a line orthogonal to the proximal side (<NUM>) of the respective baffle (<NUM>) and the distal side (<NUM>) of the respective baffle (<NUM>).