Heat exchange unit

Abstract

A heat exchange unit includes first and second plates, which are identical in configuration in a central irregularity pattern section, but different in configuration in a peripheral area. The first plate has first terraced sections projecting outward relative to a remaining part having a first flat section. The second plate has a second terraced section projecting outward relative to a remaining part having a second flat section. The first and second plates are placed alternately one upon another so that surfaces of said irregularity pattern sections face a same direction. The first terraced sections of the first plates come into contact with the second flat sections of the second plates and the first flat sections of the first plates come into contact with the second terraced sections of the second plates. The first and second plates are welded to each other at contact areas.

1 . A heat exchange unit, comprising a plurality of heat exchange plates having a predetermined pattern of irregularity, which are formed of a metallic thin sheet and combined in parallel and integrally with each other so that first spaces through which a first heat exchange fluid is to pass and second spaces through which a second heat exchange fluid is to pass are provided alternately between respective heat exchange plates, 
 wherein:    said heat exchange plates comprises first plates and second plates having a rectangular or square shape, said first and second plates being identical to each other in configuration in a central irregularity pattern section, but different from each other in configuration in a peripheral area thereof,    each of said first plates is provided, on at least a pair of parallel opposite sides of the peripheral area, with first terraced sections, each of said first terraced sections being formed by deforming parts of the first plate including predetermined areas along the pair of parallel opposite sides to project outward relative to a remaining part, said remaining part having a first flat section that is placed at a lower position than said first terraced sections;    each of said second plates is provided, on a predetermined area of the peripheral area corresponding to said first flat section of the first plate, with a second terraced section, said second terraced section being formed by deforming a part of the second plate to project outward relative to a remaining part, said remaining part of the peripheral area corresponding to said first terraced section of the first plate having a second flat section that is placed at a lower position than said second terraced section; and    said first plates and said second plates are placed alternately one upon another so that surfaces of said irregularity pattern sections face a same direction, the first terraced sections of the first plates are brought into contact with the second flat sections of the second plates and the first flat sections of the first plates are brought into contact with the second terraced sections of the second plates, and the first and second plates are welded to each other at contact areas.    
   
   
       2 . The heat exchange unit as claimed in  claim 1 , wherein: 
 the irregularity pattern section of each of the heat exchange plates has projections and recesses that are aligned respectively at predetermined intervals, said recesses being placed so as to deviate from the projections by a half of a distance between two adjacent projections, said projections and recesses being rotationally symmetric with respect to a center of the plate;    each of the plates has a symmetrical shape so as to provide a same configuration even when the plate turns on a plane thereof around the center thereof by an angle of 180 degrees;    the plates are placed one upon another so that the first plate turns on the plane thereof around the center thereof by an angle of 180 degrees upside down relative to the second plate, the projections of the first plate come into contact with backsides of the recesses of the second plate and the projections of the second plate come into contact with backsides of the recesses of the first plate, while the first terraced sections and the second flat sections come into contact with the first flat sections and the second terraced sections, respectively.    
   
   
       3 . The heat exchange unit as claimed in  claim 2 , wherein: 
 the irregularity pattern section of each of the heat exchange plates has said projections that project outward from one surface of the heat exchange plate in a form of a truncated cone or a truncated pyramid, and a plurality of intermediate protrusions each of which is placed between two projections that are adjacent to each other at a shortest distance, each of the intermediate protrusions being defined by one or more flat or curved portions that extend to opposing surfaces of the two projection, and each of the intermediate protrusions having one or more peak portions that are placed in a lower position than a top of the projection;    there is made arrangement providing simultaneously a plurality of combinations of the projection and another projection adjacent thereto at the shortest distance between which the intermediate protrusion is placed; and    a plurality of non-protruded portions each of which is placed between adjacent intermediate protrusions, each of the non-protruded portions being placed in a lowest position relative to a projecting direction of the projections, the non-protruded portions providing said recesses surrounded by the projections and the intermediate protrusions.