Heat exchanger for dryer and condensing type dryer using the same

Abstract

A heat exchanger for a dryer includes a plurality of tubes for circulating wet air and a plurality of fin structures for circulating external air which are alternately laminated together to form the heat exchanger. The fin structure includes a plurality of air passages formed by repeatedly bending a flat-type metal plate in a zigzag form. A plurality of fins are formed on side surfaces of the air passages. The fins protrude from the side surfaces of the air passages at an inclination angle. The fins are formed by partially cutting the plate forming the side surfaces of the air passages, and by the bending the cut portions of the plate into the air passages to from the fins. A heat transfer area and a heat transfer efficiency are increased, thereby enhancing a drying efficiency of a dryer having the heat exchanger.

1 . A heat exchanger, comprising: 
 a plurality of first ducts for conveying a first fluid flow; and    a plurality of second ducts for conveying a second fluid flow, wherein the plurality of first ducts and the plurality of second ducts are stacked upon one another in an alternating fashion, and wherein each of the plurality of second ducts comprises: 
 a plurality of air passages formed by repeatedly bending a flat plate in a zig-zag fashion such that the plate forms opposing sidewalls; and  
 a plurality of fins that protrude from the opposing sidewalls of the air passages, wherein the fins comprise portions of the plate that are bent so that they extend into the air passages.  
   
   
   
       2 . The heat exchanger of  claim 1 , wherein the fins are formed by selectively cutting portions of the plate that forms the plurality of air passages, and then bending the cut portions so that they form fins that extend into the air passages at an inclination angle relative to the sidewalls.  
   
   
       3 . The heat exchanger of  claim 2 , wherein the fins on each sidewall are divided into two groups, wherein the fins in the first group extend into the corresponding air passage at a first inclination angle, and wherein the fins in the second group extend into the corresponding air passage at a second inclination angle.  
   
   
       4 . The heat exchanger of  claim 3 , wherein the first group of fins are grouped together along a first portion of the air passage, and the second group of fins are grouped together along a second portion of the air passage.  
   
   
       5 . The heat exchanger of  claim 4 , wherein the first group of fins and the second group of fins extend towards one another.  
   
   
       6 . The heat exchanger of  claim 2 , wherein fins are formed on both sides of the majority of the sidewalls of the air passages.  
   
   
       7 . The heat exchanger of  claim 1 , wherein the plurality of first air ducts extend in a first direction, and wherein the plurality of second air ducts extend in a second direction that is oriented approximately perpendicular to the first direction.  
   
   
       8 . The heat exchanger of  claim 1 , wherein the heat exchanger is configured to be used in a clothing dryer, wherein the plurality of first air ducts are configured to convey a flow of heated air that is recirculated through a drum of the dryer, and wherein the plurality of second air ducts are configured to convey a flow of air from outside the dryer.  
   
   
       9 . The heat exchanger of  claim 8 , wherein the heat exchanger is configured to cool the flow of heated air in the plurality of first air ducts to condense fluid in the heated air.  
   
   
       10 . The heat exchanger of  claim 1 , wherein the plurality of fins have a height of approximately 8-10 mm.  
   
   
       11 . The heat exchanger of  claim 1 , wherein a pitch between the air passages in each of the second air ducts is approximately 3-6 mm.  
   
   
       12 . The heat exchanger of  claim 1 , wherein the fins protrude into the air passages approximately 0.4-0.7 mm.  
   
   
       13 . The heat exchanger of  claim 1 , wherein a gap between fins on opposing sidewalls of the air passages is approximately 1-3 mm.  
   
   
       14 . The heat exchanger of  claim 1 , wherein the plurality of first ducts have a rectangular cross-sectional shape.  
   
   
       15 . A clothing dryer comprising the heat exchanger of  claim 1 .  
   
   
       16 . A heat exchanger, comprising: 
 a first duct for conveying a first fluid flow; and    a second duct for conveying a second fluid flow, wherein the first duct and the second duct are stacked upon one another, and wherein the second duct comprises: 
 a plurality of separate air passages having opposing sidewalls; and  
 a plurality of fins that protrude from the opposing sidewalls of the air passages, wherein the fins comprise portions of the sidewalls that are bent so that they extend into the air passages.  
   
   
   
       17 . The heat exchanger of  claim 16 , wherein the fins are formed by selectively cutting portions of the sidewalls of the air passages, and then bending the cut portions so that they form fins that extend into the air passages at an inclination angle relative to the sidewalls.  
   
   
       18 . The heat exchanger of  claim 17 , wherein a plurality of first air ducts and a plurality of second air ducts are stacked upon one another in an alternating fashion to form the heat exchanger.  
   
   
       19 . The heat exchanger of  claim 17 , wherein the fins on each sidewall are divided into two groups, wherein the fins in the first group extend into the corresponding air passage at a first inclination angle, and wherein the fins in the second group extend into the corresponding air passage at a second inclination angle.  
   
   
       20 . The heat exchanger of  claim 19 , wherein the first group of fins are grouped together along a first portion of the air passage, and the second group of fins are grouped together along a second portion of the air passage.