Abstract:
Provided are a heat exchanger, a food handler including the heat exchanger, and a manufacturing method of the heat exchanger. The heat exchanger comprises a main body wherein the plurality of flow channels passes through the inside of the heat exchanger in a first direction and a pair of cover members which is fastened to both ends of the main body in the first direction. The plurality of flow channels is composed of a first flow channel which functions as the path for a first flowing fluid which goes in and out through the cover members and a second flow channel which is connected to the side of the main body. Thermal exchange is performed between the first flowing fluid and the second flowing fluid in the direction wherein the first and second flowing fluids cross each other inside of the main body.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    Exemplary embodiments of the present invention relate to a heat exchanger, a food handler including the heat exchanger, and a method of manufacturing the heat exchanger; and, particularly, to a heat exchanger in which a plurality of flow channels are formed therein by an extruding and cutting process and heat transfer occurs between the flow channels to simplify a working process, and a food handler including the heat exchanger, and a method of manufacturing the heat exchanger. 
         [0003]    2. Description of the Related Art 
         [0004]    In general, a heat exchanger is used to transfer heat from a fluid having high temperature to a fluid having low temperature via a heat transfer wall. The most common structure of a heat exchanger includes a metal tube serving as the heat transfer wall. There are various types of heat exchangers such as a water injection type, a double-pipe type, a finned multi-tube type, and a shell and tube type. The double-pipe heat exchanger consists of an inner tube and an outer tube, in which heat transfer occurs between a fluid in the inner tube and a fluid existing in a U-shaped portion which is positioned between the inner tube and the outer tube. The double-pipe heat exchanger has a simple construction, but its ability to transfer heat is limited. 
         [0005]    As a high-performance heat exchanger, the shell and tube heat exchanger consists of a large shell with a bundle of tubes inside it. The design of the heat exchanger may include a parallel-flow arrangement in which hot and cold fluids move in the same direction, a counter-flow arrangement in which hot and cold fluids move in the opposite direction, and a cross-flow arrangement in which fluids move in cross flow. Heat transfer mediums widely used in the industries include water, vapor, air, combusted gas, oil, mercury, sodium, potassium, and Dowtherm which is a mixture of biphenyl and diphenyl oxide. 
         [0006]    The configuration of a plate fin heat exchanger is described with reference to  FIG. 1 . A plate fin heat exchanger  10  includes hollow circular tubes  12  and plate fins  14  in which the circular tubes  12  are inserted and fixed. A hot fluid flows in the circuit tubes  12  (see reference numeral  18 ), and the plate fins  14  closely fixed to the circuit tubes  12  are stacked at regular intervals along an axial direction of the circular tubes  12 . 
         [0007]    Explaining the operation of the plate fin heat exchanger  10 , the heat of high temperature in the circular tubes  12  is dispersed to the plate fins  14  through a thermal diffusion process. In this state, cooling air  16  having low temperature flowing to the plate fins  14  cools the plate fins  14 , thereby continuously performing the heat transfer function. 
         [0008]    Meanwhile, in the plate fin heat exchanger  10 , heat transfer efficiency is determined depending upon the fitting degree of the circular tube  12  to the plate fin  14 . The circular tubes may be deformed at the time of fitting or using according to the thickness of the plate fin  14 , thereby deteriorating the quality. In addition, since the cross area of a flow passage of the circular tube  12  is generally small, the pressure load of the hot fluid flowing in the circular tube is significant, so that a high-pressure pump or a high-pressure blower fan is required. In order to overcome the above-described problem, a method of a heat exchanger with increased number of circular tubes  12  in order to decrease a pressure load has been proposed. The method has a drawback of increasing processing costs and ultimately manufacturing costs. 
       SUMMARY OF THE INVENTION 
       [0009]    The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a heat exchanger in which a body including a plurality of flow channels which are formed therein by extruding and cutting a metal shaped member, and a cover member attached to the body, are combined, thereby simplifying the working process and lowering manufacturing costs, and a food handler including the heat exchanger, and a method of manufacturing the heat exchanger. 
         [0010]    Other objects and advantages of the present invention can he understood by the following description, and will become apparent with reference to the embodiments of the present invention. Also, it will be obvious to those skilled in the art to which the present invention pertains that the objects and advantages of the present invention can be realized by the means as claimed and combinations thereof. 
         [0011]    According to one aspect of the present invention, a heat exchanger is provided, in which a heat transfer between a plurality of flowing fluids occurs, including a plurality of flow channels extending in a different direction so that the plurality of flowing fluids flows in a different direction. 
         [0012]    The flow channel may have a first flow channel, serving as a passage for a first flowing fluid, and a second flow channel serving as a passage for a second flowing fluid, and the heat transfer may occur between the first flowing fluid and the second flowing fluid in the cross direction in the heat exchanger. 
         [0013]    The first flow channel and the second flow channel may be alternatively disposed in the body. 
         [0014]    The heat exchanger further includes a pair of cover members which is fastened to both ends of the body in the first direction. The first flow channel may serve as a passage of the first flowing fluid, which passes through the cover member, in the first direction. 
         [0015]    The first and second flow channels may be formed in the body in the first direction by an extruding process. 
         [0016]    The first or second flow channel may be provided with a heat exchange fin with a predetermined shape protruding from the flow channel. 
         [0017]    The heat exchange fin may be oppositely disposed in a staggered manner on an inner surface of either the first or second flow channel which is provided with the heat exchange fin. 
         [0018]    The second flow channel may be formed to communicate with a lateral surface of the body by a cutting process. 
         [0019]    The cover member can prevent the second flowing fluid, which flows through the second flow channel from the lateral surface of the body, from being discharged from the body in the first direction. 
         [0020]    According to another aspect of the present invention to achieve the above-described object, there is provided a method of manufacturing the heat exchanger set forth in the above-described invention, including: extruding a body so that some of the plurality of flow channels in any one direction are formed to have a different height; cutting a lateral surface of the body in a direction different from the direction of the flow channel by a depth until a distal end of the flow channel having the different height is exposed outward; and attaching a cover member to both ends of the flow channel having the exposed distal end. 
         [0021]    According to still another aspect of the present invention to achieve the above-described object, there is provided a food handler including the heat exchanger set forth in the above-described invention, wherein heat transfer occurs between exhaust gas generated from a drying oven of the food handler and cold air supplied from an exterior flow in the heat exchanger. 
         [0022]    According to still another aspect of the present invention to achieve the above-described object, there is provided a food handler including the heat exchanger manufactured by the method. 
         [0023]    With the configuration described above, the present invention is characterized in that as the flowing fluids having thermal energy of the different temperatures flow in the flow channels formed in the body in the cross or perpendicular direction, the heat transfer can occur effectively. Further, the heat exchanger can be rapidly manufactured with a simple method employing the above-described simultaneous extruding process, the process of cutting the upper and lower ends of the body, and the process of attaching the cover member to the front and rear surfaces of the body when the body is formed, thereby improving its productivity and thus reducing the cost of manufacturing. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]    The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this invention, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings: 
           [0025]      FIG. 1  is a perspective view illustrating a configuration of a heat exchanger of the related art. 
           [0026]      FIG. 2  is a perspective view illustrating a configuration of a heat exchanger according to one embodiment of the present invention. 
           [0027]      FIG. 3  is a perspective view illustrating a state in which a body, which is a constitutional element of the heat exchanger according to the present invention, is formed by an extruding process. 
           [0028]      FIG. 4  is a perspective view illustrating a state in which second flow channels formed in the body by a cutting process of a lateral surface of the body is exposed from the lateral surface of the body. 
           [0029]      FIG. 5  is an exploded perspective view illustrating a state in which a pair of cover members is engaged with front and rear surfaces of the body. 
           [0030]      FIG. 6  is a front view when seen from direction A in  FIG. 4 . 
           [0031]      FIG. 7  is a plan view when seen from direction B in  FIG. 4 . 
           [0032]      FIG. 8  is a cross-sectional view taken along the line C-C in  FIG. 4 . 
           [0033]      FIG. 9  is a cross-sectional view taken along the line D-D in  FIG. 4 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0034]    The above and other objects, and new features of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings. A heat exchanger, a food handler including the heat exchanger, and a method of manufacturing the heat exchanger will now be described in detail with reference to the accompanying drawings. 
         [0035]    The configuration of a heat exchanger  100  according to one embodiment of the present invention will be described with reference to  FIGS. 2 to 5 . The heat exchanger  100  includes a body  110  having a plurality of flow channels  120  formed therein, and a pair of cover members  130  fastened to both ends of the front and rear surfaces of the body  110 . Fastening grooves  112  formed in corner portions of the front and rear surfaces of the body  110  are provided to correspond to fastening holes  131  formed in corner portions of the cover member  130 , so that the fastening grooves  112  are engaged with the fastening holes  131  by separate fastening members (not illustrated). 
         [0036]    The body  110  is made of single piece which can be made by an extruding process, and has the same cross section at any point in a longitudinal direction thereof. The body is provided as a product of a desired shape by the extruding process within a short time. 
         [0037]    The plurality of flow channels  120  have first flow channels  122  serving as a passage for a first flowing fluid passing through the cover member  130 , and second flow channels  124  serving as a second flowing fluid and selectively communicating with a lateral surface of the body  110 . In  FIG. 2 , a moving direction of the first flowing fluid passing the front and rear surfaces of the body is referred to as a first direction  102 , and a moving direction of the second flowing fluid passing upper and lower ends of the lateral surface of the body is referred to as a second direction  104 . The first direction is set as an X-axis on a rectangular coordinate system, and the second direction is set as a Y-axis. The first and second directions are set to be perpendicular to each other for convenience, but the direction setting is not limited thereto. 
         [0038]    The first flowing fluid flows in the rear surface of the body  110  in the first direction  102 , and flows out from the front surface of the body  110  via the first flow channels  122 . The flow of the first flowing fluid is not interrupted by the cover member  130  in the above process. 
         [0039]    The second flowing fluid flows in the upper end of the lateral surface of the body  110  in the second direction  104 , and flows out from the lower end of the lateral surface of the body  110  via the second flow channels  124 . The communication of the upper and lower ends of the lateral side of the body  110  and the second flow channels  124  is achieved by a process of cutting the upper and lower ends of the lateral side of the body  110 . Referring to  FIG. 4 , the body  110  is provided on both sides thereof with a constant stepped portion which is formed by the above cutting process. The stepped portion means a height difference between a machined surface  116  which is subjected to the cutting process, and a non-machined reference surface  118 . The second flow channels  124  are exposed to both sides of the body  110  due to the stepped portion. 
         [0040]    The cover member  130  prevents the second flowing fluid from being discharged from the front surface of the body  110 . This is achieved by forming a configuration in which the cover member  130  closes the portion of the second flow channels  124  which communicate with the front and rear surfaces of the body  110 . 
         [0041]    The cover member  130  is provided with through-holes  134  through which the first flowing fluid entering the body  110  in the first direction  102  flows. These through-holes  134  are formed by a process of piercing a metal plate using a press machine. A shield portion  132  formed between the through-holes  134  prevents the second flowing fluid from being leaked from the front and rear surfaces of the body  110 . Since a sealing member (not illustrated) is attached to the inner surface of the cover member  130 , it is possible to prevent the flowing fluid from being leaked in the case in which the cover member  130  is brought in close contact with the body  110 . 
         [0042]    The first flow channels  122  and the second flow channels  124  are alternatively and continuously disposed in the body  110 , as illustrated in  FIG. 6 . That is, since the second flow channels  124  are disposed on both adjacent sides of the first flow channels  122 , the heat transfer can smoothly occur between the first flowing fluid flowing in the first flow channels  122  and the second flowing fluid flowing in the second flow channels  124 . A plurality of heat exchange fins  114  of a predetermined shape are formed between the flow channels  120  to enhance the heat exchange performance between the first and second flowing fluids. 
         [0043]    The heat exchanger  100  according to the present invention can be applied to all apparatuses in which the heat exchange or distribution should be performed, and more particularly, to a heat exchanger for a food handler. In the food handler, hot and humid exhaust gas generated from a drying oven in which food garbage is ground and dried, and cold air supplied from the exterior, flow in the flowing channels  120  of the heat exchanger  100  in a cross direction to exchange the heat. 
         [0044]    In particular, referring to  FIG. 9 , the second flowing fluid entering the second flow channels  124  in the second direction  104  flows in a streamlined way due to the presence of the heat exchange fins  114 , so that the second flowing fluid comes in contact with the surface of the second flow channels  124 . This increases mobility of the heat through heat conduction between the flowing channels  120 . In order to support the streamlined movement of the second flowing fluid, the heat exchanger fins  114  are formed in a staggered pattern on both sidewalls of the second flow channels  124  in the second direction  104 . 
         [0045]    The flow channels  120  formed in the body  110  by the extruding process have different length in the second direction  104 . That is, referring to  FIG. 8 , the second flow channels  124  are formed rather longer than the first flow channels  122  in the second direction  104 , so that the upper and lower ends of the second flow channels  124  are formed closer to the side of the body  110  than the first flow channels  122 .  FIG. 9  illustrates the cross section of the body  110  which is subjected to the cutting process. The cutting process is carried out until the upper and lower portions of the second flow channels  124  are exposed outward, and the upper and lower portions of the first flow channels  122  are not exposed. 
         [0046]    The second flowing fluid entered through the upper end of the body  110  is discharged from the lower end of the body  110  through the second flow channels  124 . In this process, the second flowing fluid flows in the second flow channels  124  in the streamlined way with a zigzag pattern due to the protruding shape of the heat exchange fins  114  (see reference numeral  125 ). 
         [0047]    The method of manufacturing the heat exchanger according to one embodiment of the present invention will now be described with reference to  FIGS. 2 to 9 . 
         [0048]    Firstly, the extruding process is carried out by extruding a molten shaping material into a mould having the shape corresponding to the body  110  of the present invention using a pump. The extruding process is classified into a positive extrusion method in which an extruding direction of the shaping material is the same as a direction of pressure applied from the exterior, and a negative extrusion method in which the extruding direction of the shaping material is opposite to the direction of pressure applied from the exterior. In the present invention, the plurality of flow channels  120  is evenly formed in the body  110  through the above-described simultaneous extruding process.  FIG. 3  illustrates the body  110  formed by the extruding process, in which the flow channels  120  are formed to have the uniform shape in the first direction  102  (X-axis). 
         [0049]    After the extruding process, the process of cutting the upper and lower ends of the body  110  is carried out. The upper and lower portions of the second flow channels  124  are exposed outward, while the upper and lower portions of the first flow channels  122  are not exposed.  FIG. 4  illustrates the state in which the upper and lower sides of the body  110  are subjected to the cutting process. Through the process, the second flowing fluid enters the second flow channels  124  via the upper surface of the body  110 . 
         [0050]    After the process of cutting the body  110  is carried out, the cover members  130  are attached to the front and rear surfaces of the body  110 . The cover member  130  prevents the second flowing fluid from being discharged from the body  110  in the first direction  102 . This is achieved by forming the configuration in which the cover member  130  closes the portion of the second flow channels  124  which communicate with the front and rear surfaces of the body  110 . 
         [0051]    As described above, the present invention is characterized in that as the flowing fluids having thermal energy of the different temperatures flow in the flow channels formed in the body in the cross or perpendicular direction, the heat transfer can occur effectively. Further, the heat exchanger can be easily and rapidly manufactured with a simple method employing the above-described simultaneous extruding process once, the process of cutting the upper and lower ends of the body, and the process of attaching the cover member to the front and rear surfaces of the body when the body is formed, thereby improving its productivity and thus reducing the cost of manufacturing. 
         [0052]    While the present invention has been described with respect to specific embodiments thereof, the present invention is not limited thereto. It will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims.