Patent Publication Number: US-9835356-B1

Title: Fluid heating apparatus utilizing at least two fluid paths

Description:
BACKGROUND 
     Field 
     The present disclosure relates to fluid heaters and more particularly pertains to a new fluid heating apparatus utilizing at least two fluid paths for facilitating heating of fluid at higher flow rates. 
     SUMMARY 
     In one aspect, the present disclosure relates to a fluid heater for a heating fluid and having a fluid inlet and a fluid outlet. The fluid heater may comprise a heater housing defining an interior with a combustion chamber being positioned in the interior of the housing, and fluid tubing in the interior of the housing and adjacent to the combustion chamber, with the fluid tubing defining a fluid path through the housing between the fluid inlet and the fluid outlet. The fluid heater may also comprise a burner configured to combust a fuel in the combustion chamber to heat the fluid tubing. At least a portion of the fluid path may comprise a bifurcated fluid path between the fluid inlet and the fluid outlet. 
     In another aspect, the disclosure relates to a fluid heating system comprising a reservoir having an interior configured to hold a fluid, and the reservoir having a reservoir inlet and a reservoir outlet. The system also comprising a fluid heater for a heating fluid and having a fluid inlet in fluid communication with the interior of the reservoir and a fluid outlet in communication with the interior of the reservoir. The fluid heater may comprise a heater housing defining an interior with a combustion chamber being positioned in the interior of the housing, and fluid tubing in the interior of the housing and adjacent to the combustion chamber, with the fluid tubing defining a fluid path through the housing between the fluid inlet and the fluid outlet. The fluid heater may also comprise a burner configured to combust a fuel in the combustion chamber to heat the fluid tubing. At least a portion of the fluid path may comprise a bifurcated fluid path between the fluid inlet and the fluid outlet. 
     There has thus been outlined, rather broadly, some of the more important elements of the disclosure in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional elements of the disclosure that will be described hereinafter and which will form the subject matter of the claims appended hereto. 
     In this respect, before explaining at least one embodiment or implementation in greater detail, it is to be understood that the scope of the disclosure is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The disclosure is capable of other embodiments and implementations and is thus capable of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting. 
     As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present disclosure. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present disclosure. 
     The advantages of the various embodiments of the present disclosure, along with the various features of novelty that characterize the disclosure, are disclosed in the following descriptive matter and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure will be better understood and when consideration is given to the drawings and the detailed description which follows. Such description makes reference to the annexed drawings wherein: 
         FIG. 1  is a schematic diagram of a system including a fluid heating apparatus utilizing at least two fluid paths according to the present disclosure. 
         FIG. 2  is a schematic diagram of the fluid heating apparatus, according to an illustrative embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     With reference now to the drawings, and in particular to  FIGS. 1 and 2  thereof, a new fluid heating apparatus utilizing at least two fluid paths embodying the principles and concepts of the disclosed subject matter will be described. 
     Applicants have recognized that a typical fluid heater may include a heat exchanger coil of tubing which defines a single flow or fluid path through the fluid heater such that fluid entering an inlet of the fluid heater has a single path to pass through to reach the fluid outlet of the fluid heater. Such a design may have problems handling relatively higher volumetric flow rates. The fluid flow rate handled by a fluid heater can be increased by speeding up the velocity of the fluid through the heat exchanger, but maximizing the fluid velocity through the heat exchanger can have at least two detrimental effects. The pressure drop through the coil would be substantially more (e.g., twice as much), and therefore require a larger (and thus more expensive) pump that would be able to produce the required pressure to overcome the greatly increased pressure drop. Another problem is if the fluid velocity is too high, the fluid will erode the wall of the tube and fail prematurely. 
     In recognition of these problems, applicants have developed a fluid heater in which a bifurcated fluid path extends through at least a portion of the heat exchanger which effectively allows for a higher flow rate through the heat exchanger without significantly increasing the velocity of the fluid, and thus can avoid significant extension of the length of the fluid path and avoid some of the tubing erosion caused by higher fluid velocities. 
     In one aspect, the disclosure is directed to a system  1  in which a reservoir  2  is employed to hold a relatively large amount of fluid in reserve for use in a short period of time. Such applications include, for example, reservoirs used for holding a large quantity of water for use in mixing batch of concrete at a ready mix plant, in which a large of amount of water needs to be added to the cement and aggregate mix in a relatively short time period as the concrete is produced. The fluid may be introduced into the reservoir  2  through a reservoir inlet  3  from a fluid source, and may be drawn from the reservoir through a reservoir outlet  4 . A fluid heater  10  may be utilized to heat and maintain the temperature level of the fluid in the reservoir  2  through interchange lines  5 ,  6  that permit the exchange of fluid from the reservoir to the fluid heater and from the fluid heater to the reservoir. 
     In another aspect, the disclosure is directed to the fluid heater  10  for heating fluid passing through the heater. The fluid heater  10  may have a fluid inlet  12  into which fluid to be heated is introduced into the apparatus, and a fluid outlet  14  from which heated fluid is dispensed from the apparatus. In a system  1 , the interchange line  5  may be connected to the fluid inlet  12  and the fluid outlet may be connected to the interchange line  6 . Generally, fluid to be heated flows into the inlet  12 , flows from the inlet  12  to the outlet  14 , and then flows out of the outlet  14 . The fluid inlet  12  is upstream of the fluid outlet  14 , and conversely the fluid outlet is downstream of the fluid inlet. 
     In some embodiments, the fluid heater  10  includes a heater housing  16  which may define an interior of the housing, and the interior may be surrounded by a perimeter wall  18  which may be generally cylindrical in shape. The heater housing may have an intake opening  17  for generally receiving air to be used in fuel combustion and an exhaust opening  19  through which exhaust gases from the fuel combustion is able to exit the interior of the heater housing  16 . A combustion chamber may be positioned in the interior of the housing, and in some embodiments the chamber is generally centrally located in the interior. 
     The fluid heater  10  may also include fluid tubing for defining a fluid path through the heater and the housing between the fluid inlet  12  and the fluid outlet  14 . Significantly, the fluid tubing of the fluid heater may be configured so that at least a portion of the fluid path comprises a bifurcated fluid path  20  between the fluid inlet  12  and the fluid outlet  14 . The bifurcated fluid path  20  may extend from an inlet juncture  22  to an outlet juncture  24 . The inlet juncture  22  may not correspond to the fluid inlet  12  of the heater, and an inlet tube  26  may extend from the fluid inlet  12  to the inlet juncture  22 . Similarly, the outlet juncture  24  may not correspond to the fluid outlet  14  of the heater  10 , and an outlet tube  28  may extend from the outlet juncture  24  to the fluid outlet  14 . A fluid inlet flow may be carried in the inlet tube  26  from the inlet  12  to the inlet juncture and may be divided at the inlet juncture  22 . A fluid outlet flow may be collected or combined at the outlet juncture  24  to be carried in the outlet tube  28  to the outlet  14 . The inlet fluid flow and the outlet fluid flow may be singular or unified fluid flows, and in many applications the outlet fluid flow will be substantially equal to the inlet fluid flow. 
     The bifurcated fluid path  20  may include at least two fluid subpaths and illustratively may include a first subpath  30  and a second subpath  32 . The first subpath  30  and the second subpath  32  may each extend from the inlet juncture  22  to the outlet juncture  24  in a parallel configuration. (It should be recognized that for the purposes of this description, the term “parallel” is not intended to mean or require a parallel quality in the geometric sense between paths or tubes, and instead is intended to generally mean that the paths or tubes have common beginning points and end points between which both extend.) A first fluid flow may move through the first subpath  30  and a second fluid flow may move through the second subpath  32 . The first fluid flow does not move through the second subpath and similarly the second fluid flow does not move through the first subpath. The first and second fluid flows are thus parallel to and separate of each other between the junctures. 
     The first subpath  30  may be defined by a first conduit  40  and a second subpath  32  may be defined by a second conduit  42 . The first conduit  40  may be formed into a first coil  44 , and the second conduit  42  may be formed into a second coil  46 . The fluid tubing of the first  40  and second  42  conduits may be positioned in or adjacent to the combustion chamber in the housing. In some embodiments, the second coil  46  may be nested inside the first coil  44  although other configurations of the first conduit  40  and second conduit  42  may be utilized. The first conduit  40  may have a first length between the inlet juncture  22  and the outlet juncture  24 , and similarly the second conduit  42  may have a second length measured between the inlet juncture and outlet juncture. In some embodiments, the second length of the second conduit may be substantially equal, and in some embodiments the second length may be less or shorter than the first length of the first conduit  40 . The first  44  and second  46  coils may extend about a central axis of the housing. In some embodiments, the coils  44 ,  46  are centered on at least a portion of the combustion chamber of the housing. During operation of the fluid heater  10 , the fluid inlet flow from the inlet tube  26  may be divided at the inlet juncture  22  into the first fluid flow which flows into the first subpath  30  and the second fluid flow which flows into the second subpath  32 . The first fluid flow from the first subpath  30  and the second fluid flow from the second subpath  32  may be combined together at the outlet juncture  24  into the fluid outlet flow in the outlet tube  28 . 
     The fluid heater  10  may also include a fluid pump  50  which is configured to move fluid along the fluid path through the heater ends and more specifically through the bifurcated fluid path  20 . In some embodiments, the fluid pump  50  may be in communication with the fluid path upstream of the bifurcated fluid path  20  and may be in communication with the fluid path at the inlet tube  26  in order to pump or push fluid through the fluid path prior to the fluid passing through the conduits  40 ,  42  adjacent or in the combustion chamber. 
     The fluid heater  10  may also include a burner  52  which is configured to combust a fuel to generate combustion exhaust gases to move along an exhaust gas movement path generally located between the intake opening and the exhaust opening of the housing. The burner  52  may generally be configured to direct combustion exhaust gases about the fluid tubing, and may be configured to direct the combustion exhaust gas through the center of the coils  44 ,  46  in order to heat the material forming the coils as well as the fluid contained within the coils. In some embodiments, a portion of the exhaust gas movement path extends through a center of the coils  42 ,  44 , and may also be directed to paths about the exterior or outside of the coils. 
     Other elements may be included in the heater  10 , including a temperature control device for at least one, and optionally both, of the fluid subpaths  30 ,  32 , and may be connected to the respective conduits  40 ,  42  for sensing the condition of the respective first and second fluid flows. A flow switch device may be provided for at least one, and optionally both, of the subpaths  30 ,  32 , and may also be connected to the respective conduits  40 ,  42  for sensing the condition of the respective first and second fluid flows. A temperature limiting device may be provided for the heater  10 , and may be in communication with the flow path such as at the outlet tube to sense the temperature of the fluid outlet flow. A relief valve device may be provided for the heater  10 , and may be in communication with the flow path at a location such as at the outlet tube to sense the pressure of the fluid outlet flow, and relieve a pressure condition that exceeds predetermined limits. 
     It should be appreciated that in the foregoing description and appended claims, that the terms “substantially” and “approximately,” when used to modify another term, mean “for the most part” or “being largely but not wholly or completely that which is specified” by the modified term. 
     It should also be appreciated from the foregoing description that, except when mutually exclusive, the features of the various embodiments described herein may be combined with features of other embodiments as desired while remaining within the intended scope of the disclosure. 
     With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the disclosed embodiments and implementations, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art in light of the foregoing disclosure, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present disclosure. 
     Therefore, the foregoing is considered as illustrative only of the principles of the disclosure. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the disclosed subject matter to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to that fall within the scope of the claims.