Patent Description:
<FIG> shows a typical construction of a plate heat exchanger <NUM>'. The plate heat exchanger <NUM>' comprises a plurality of heat transfer plate <NUM>' stacked on top of each other. The heat transfer plates <NUM>' are formed with patterns such that flow paths are formed between each set of neighbouring heat transfer plates <NUM>'. Openings <NUM> and <NUM> are formed in the heat transfer plates <NUM>' to form inlets and outlets for fluids to these flow paths. Gaskets <NUM>' are positioned between the heat transfer plates <NUM>' in gasket grooves <NUM>' formed in the heat transfer plates. The gasket is arranged at an edge portion of the heat transfer plate to seal the flow paths and at an area around the openings to seal pairs of the openings, such that only two of them have flow access to the flow path formed at one side of the heat transfer plate, while the other two is sealed therefrom. <CIT> is considered to be the closest prior art to claim <NUM> and discloses a coupling structure of a heat transfer plate and a gasket for use in a plate type heat exchanger, wherein a gasket groove, formed along the outer circumference of respective fluid passage holes and the heat transfer plate, and the gasket to be inserted into the gasket groove have a toothed engagement coupling structure. <CIT> discloses a heat exchanger formed of plates in series with flow regions between adjacent plates. Each plate has a sealing groove and seal. The groove base is corrugated, forming a recess of greatest width smaller than the sealing groove width. A seal has a bottom with approximately the same shape as the sealing groove base and a sealing surface approximately the same shape as the base of the adjacent plate. <CIT> discloses a heat exchanger comprising a stack of heat exchanger plates (<NUM>, 1a, 1b, <NUM> c) formed of sheet metal having a three-dimensional structured pattern (<NUM>, <NUM>), each heat exchanger plate (<NUM>,<NUM> a, 1b, <NUM> c) having a groove (<NUM>), a gasket (<NUM>) being arranged in said groove (<NUM>) and resting against an adjacent heat exchanger plate (<NUM> a), said groove (<NUM>) having a bottom inner surface (<NUM>), said inner surface bottom (<NUM>) having at least a protrusion (<NUM>, <NUM>) directed to said adjacent heat exchanger plate (1a). It is intended to minimize the risk of a leakage. To this end in the region of said protrusion (<NUM>, <NUM>) said gasket (<NUM>) is compressed more than in a region out of said protrusion (<NUM>, <NUM>).

Especially in the opening areas the pressures are high, but the gasket is disposed at only one side of the heat transfer plate, while the other side is unsupported, thus forming a weak section.

As shown in <FIG>, these weak sections in the areas of the high pressures may be deformed.

The present disclosure provides a heat transfer plate for a plate heat exchanger and a plate heat exchanger that at least partly alleviate the deformation of the heat transfer plate at the gasket groove in use.

According to the present invention there is provided a plate heat exchanger according to claim <NUM>.

According to a non claimed arrangement, the recess is disposed on a middle portion of the at least one segment in a width direction of the at least one segment of the bottom wall body.

According to a non claimed arrangement, the recess comprises a first recess and a second recess, the at least one segment comprises a first segment and a second segment, the first recess and the second recess are formed on the first segment and the second segment, respectively, and the first recess is deeper than the second recess.

According to embodiments of the present disclosure, the heat transfer plate further comprises: an inlet opening formed in the plate body for forming an inlet port of the plate heat exchanger; and an outlet opening formed in the plate body for forming an outlet port of the plate heat exchanger. The first segment is in an area around the inlet opening and the outlet opening, and the second segment extends in a direction from the inlet opening to the outlet openings along an edge portion of the plate body.

According to embodiments of the present disclosure, the first segment comprises a circular portion and a connection portion connecting the circular portion to the second segment.

According to embodiments of the present disclosure, the bottom wall body comprises the at least one segment, and the other segment that is essentially flat.

According to embodiments of the present disclosure, each of gaskets has a gasket body with a top surface, and a protrusion protruding from a middle portion, in a width direction of the top surface, of the top surface, and extending along a length direction of the gasket body.

According to embodiments of the present disclosure, the recess comprises two recesses respectively disposed on two sides of the at least one segment in a width direction of the at least one segment, and spaced from each other in the width direction of the at least one segment by a predetermined distance, and a top of the protrusion of each of gaskets has a width less than the predetermine distance.

According to a non claimed arrangement, the recess is disposed on a middle portion of the at least one segment in a width direction of the at least one segment of the bottom wall body, and a top of the protrusion of each of gaskets has a less width than the recess.

These and other objects, features and advantages of the present disclosure will become apparent in light of the detailed description of embodiments thereof, as illustrated in the accompanying drawings.

Referring to <FIG>, a plate heat exchanger <NUM> according to embodiments of the present disclosure is shown. Referring to <FIG>, the plate heat exchanger <NUM> comprises: a plurality of heat transfer plates <NUM> which are stacked on top of each other; and gaskets <NUM> disposed in gasket grooves <NUM> of some of the plurality of heat transfer plates <NUM>.

Referring to <FIG> and <FIG>, each of gaskets <NUM> may have a gasket body <NUM> with a top surface <NUM>, and a protrusion <NUM>. The protrusion <NUM> protrudes from a middle portion, in a width direction of the top surface <NUM>, of the top surface <NUM>, and extends along a length direction of the gasket body <NUM>. The protrusion <NUM> may have a tapered section.

In an embodiment, referring to <FIG>, the heat transfer plate <NUM> comprises a plate body <NUM> having a first side <NUM> and a second side <NUM> opposite to the first side <NUM>. The heat transfer plate <NUM> further comprises a gasket groove <NUM>. The gasket groove <NUM> is formed on the plate body <NUM>, is depressed from the plate body <NUM> in a direction from the first side <NUM> towards the second side <NUM> and has a bottom wall <NUM> with a bottom wall body <NUM>. The heat transfer plate <NUM> further comprises a recess <NUM>. The recess <NUM> is formed on at least one first segment <NUM> (<FIG>) of the bottom wall body <NUM> in a length direction of the bottom wall body <NUM>, is depressed from the bottom wall body <NUM> in the direction from the first side <NUM> towards the second side <NUM> and extends along the first segment <NUM> of the bottom wall body <NUM> of the gasket groove <NUM>.

In <FIG>, the first segment <NUM> of the bottom wall body <NUM> where the recess <NUM> is formed is indicated by solid lines, while the other segment of the bottom wall body <NUM> where no recess <NUM> is formed is denoted by dashed lines. The other segment of the bottom wall body <NUM> may be essentially flat.

Referring to <FIG>, the recess <NUM> may comprise two recesses <NUM>. The two recesses <NUM> are respectively disposed on two sides <NUM>, <NUM> of the at least one first segment <NUM> in a width direction of the at least one first segment <NUM> and are spaced from each other in the width direction of the at least one first segment <NUM> by a predetermined distance. For example, a top of the protrusion <NUM> of each of gaskets <NUM> may have a width less than the predetermine distance so that the top of the protrusion <NUM> is fitted in a depression <NUM> formed on the bottom wall <NUM> by the two recesses <NUM>.

In one embodiment relating to any of the indicated embodiments in the figures, the gasket at its lower surface <NUM> is has a shape that does not reflect the recess(es) <NUM>, <NUM>'. In one embodiment the lower surface is essentially flat. When squeezed between two heat transfer plates <NUM> the lower surface <NUM> is deformed into the recess(es) <NUM>, <NUM>'.

In an arrangement not falling under the scope of the claims, referring to <FIG>, instead of the two recesses <NUM> shown in <FIG>, the recess <NUM>' is disposed on a middle portion <NUM> of the at least one segment <NUM> in a width direction of the at least one segment <NUM> of the bottom wall body <NUM>. For example, a top of the protrusion <NUM> of each of gaskets <NUM> may have a less width than the recess <NUM>'.

In the embodiments a second segment <NUM>' of the bottom wall body <NUM> if the bottom wall <NUM> is different from that the first second segment <NUM>. In one embodiment the second r segment <NUM>' bottom wall body <NUM> of the bottom wall <NUM> is essentially flat. In other more general embodiments, a section of the bottom wall body <NUM> of the bottom wall <NUM> where no recess is formed may be essentially flat.

In a further embodiment, referring to <FIG>, <FIG>, <FIG>, the recess <NUM> comprises a first recess <NUM> and a second recess <NUM>, the at least one segment <NUM>, <NUM>' comprises a first segment <NUM> as indicated by the solid lines shown in <FIG> and a second segment <NUM>' as indicated by the dashed lines shown in <FIG>, the first recess <NUM> and the second recess <NUM> are formed on the first segment <NUM> and the second segment <NUM>', respectively, and the first recess <NUM> is deeper than the second recess <NUM>. Alternatively, referring to <FIG>, <FIG>, <FIG>, the recess <NUM>' comprises a first recess <NUM>' and a second recess <NUM>', the at least one segment <NUM>, <NUM>' comprises a first segment <NUM> as indicated by the solid lines shown in <FIG> and a second segment <NUM>' as indicated by the dashed lines shown in <FIG>, the first recess <NUM>' and the second recess <NUM>' are formed on the first segment <NUM> and the second segment <NUM>', respectively, and the first recess <NUM>' is deeper than the second recess <NUM>'.

Referring to <FIG>, and <FIG>, the heat transfer plate <NUM> further comprises: an inlet opening <NUM> formed in the plate body <NUM> for forming an inlet port of the plate heat exchanger <NUM>; and an outlet opening <NUM> formed in the plate body <NUM> for forming an outlet port of the plate heat exchanger <NUM>. In an embodiment relevant to any of the previous embodiments, the first segment <NUM> is in an area around the inlet opening <NUM> and the outlet opening <NUM>, and the second segment <NUM>' extends in a direction from the inlet opening <NUM> to the outlet openings <NUM> along an edge portion of the plate body <NUM>. For example, the second segment <NUM>' extends in a length direction of the heat transfer plate <NUM>. The first segment <NUM> may comprise a sealing <NUM> and a first connection portion <NUM> connecting the sealing portion <NUM> to the second segment <NUM>'. The sealing portion <NUM> is positioned to seal an opening from the flow path formed at the respective side of the heat transfer plate <NUM>, and thus may be formed at the circumference of said opening, and possible being circular. The segment <NUM> of the bottom wall body <NUM> where the recess <NUM> is formed may be set according to a specific structure and an operational pressure of a plate heat exchanger and is not limited to the described embodiments.

In an embodiment relevant to any of the previous embodiments, the first segment <NUM> further comprises a semi-sealing portion <NUM> positioned in relation to an active opening inlet or outlet relative to the flow path formed at the respective side of the heat transfer plate <NUM>, and thus may be formed at a part of the circumference of said opening, and possible being semi-circular. A second connection portion <NUM> may connect the semi-sealing portion <NUM> to the second segment <NUM>'.

The first <NUM> and/or second <NUM> connection portions may be straight, curved, bend, meandering, and may reach into the part of the bottom wall <NUM> with a bottom wall body <NUM> extending at the long edge of the heat transfer plate <NUM> from an inlet to an outlet.

With the heat transfer plate <NUM> and the plate heat exchanger <NUM> according to the embodiments of the present disclosure, the portion of the heat transfer plate <NUM> where the gasket groove <NUM> is formed is reinforced by forming the recess <NUM> and <NUM>', thereby alleviating deformation of the portion of the heat transfer plate <NUM> and thus avoid possible fluid leakage.

Claim 1:
A plate heat exchanger (<NUM>), comprising:
a plurality of heat transfer plates (<NUM>) , which are stacked on top of each other; and
gaskets (<NUM>) disposed in the gasket grooves (<NUM>) of some of the plurality of heat transfer plates (<NUM>).
where the heat transfer plates (<NUM>) comprise:
a plate body (<NUM>) having a first side (<NUM>) and a second side (<NUM>) opposite to the first side (<NUM>);
a gasket groove (<NUM>) formed on the plate body (<NUM>), depressed from the plate body (<NUM>) in a direction from the first side (<NUM>) towards the second side (<NUM>), and having a bottom wall (<NUM>), the bottom wall (<NUM>) having a bottom wall body (<NUM>); and
an inlet opening (<NUM>) formed in the plate body (<NUM>) for forming an inlet port of the plate heat exchanger (<NUM>); and
an outlet opening (<NUM>) formed in the plate body (<NUM>) for forming an outlet port of the plate heat exchanger (<NUM>), and:
wherein the gasket groove (<NUM>) includes at least one first segment (<NUM>) and one second segment (<NUM>'), the first segment (<NUM>) being in an area around the inlet opening (<NUM>) and the outlet opening (<NUM>), and the second segment (<NUM>') extending in a direction from the inlet opening (<NUM>) to said outlet openings (<NUM>) along an edge portion of the plate body (<NUM>), where in the heat exchanger (<NUM>) a gasket is disposed at only one side of the heat transfer plate in the first segment (<NUM>), while the other side is unsupported,
where
two recesses (<NUM>) are formed on the first segment (<NUM>) of the bottom wall body (<NUM>) in a length direction of the bottom wall body (<NUM>) respectively disposed on two sides (<NUM>, <NUM>) of the first segment (<NUM>) in a width direction of the first segment (<NUM>), and spaced from each other in the width direction of the first segment (<NUM>) and
depressed from the bottom wall body (<NUM>) in the direction from the first side (<NUM>) towards the second side (<NUM>), and extending along the first segment (<NUM>) of the bottom wall body (<NUM>) of the gasket groove (<NUM>), the plate heat exchanger being characterized in that:
said second segment (<NUM>') of the bottom wall body (<NUM>) of the bottom wall (<NUM>) is different from that of the first segment (<NUM>), wherein no recess (<NUM>) is formed in the second segment (<NUM>') bottom wall body (<NUM>) of the bottom wall (<NUM>) which is essentially flat.