Evaporator and process for fabricating same

Abstract

An evaporator 1 comprises a flat tube 2 bent zigzag, and a corrugated fin 3 disposed between each adjacent pair of straight tube portions 2 a of the flat tube 2 and brazed thereto by the flux brazing method. The flux remains on the surface of the portion of the corrugated fin 3 not brazed to the straight tube portions 2 a in an amount of 0.03 to 1 g/m 2. @ The evaporator 1 is fabricated by a process including applying the flux in an amount of 0.05 to 2.8 g/m 2 to the outer surface of a zigzag flat tube 2, disposing a corrugated fin 3 between each adjacent pair of straight tube portions 2 a of the flat tube 2 and brazing the fin 3 to the flat tube 2. The evaporator 1 can be effectively inhibited from emanating odor.

1 . An evaporator comprising a refrigerant passing hollow body, and a fin brazed to an outer surface of the hollow body by the flux brazing method, the portion of the fin not brazed to the hollow body having a flux remaining on a surface thereof in an amount of 0.03 to 1 g/m 2 .  
   
   
       2 . An evaporator according to  claim 1  wherein the flux remains on the surface of the portion of the fin not brazed to the hollow body in an amount of 0.05 to 0.5 g/m 2 .  
   
   
       3 . An evaporator according to  claim 1  wherein the flux is a noncorrosive fluoride flux.  
   
   
       4 . An evaporator according to  claim 1  wherein the refrigerant passing hollow body comprises a flat tube bent zigzag, and the fin comprises a corrugated fin made of a brazing sheet having a brazing material layer on opposite sides thereof, the corrugated fin being disposed between and brazed to each adjacent pair of straight tube portions of the zigzag flat tube.  
   
   
       5 . An evaporator according to  claim 1  which comprises a plurality of straight flat tubes each constituting the refrigerant passing hollow body and wherein the fin comprises a corrugated fin made of a brazing sheet having a brazing material layer on opposite sides thereof, the plurality of flat tubes being arranged in parallel as spaced from one another, the corrugated fin being disposed between and brazed to each adjacent pair of flat tubes.  
   
   
       6 . An evaporator according to  claim 1  which comprises a plurality of refrigerant passing hollow bodies each comprising two plates made of a brazing sheet having a brazing material layer on opposite sides thereof and brazed to each other at peripheral edge portions thereof, the two plates defining therebetween a bulging refrigerant channel and a bulging header-forming portion communicating with each of opposite ends of the refrigerant channel, the fin comprising a corrugated fin, the plurality of hollow bodies being stacked so that outer surfaces of the header-forming portions of each adjacent pair of hollow bodies are in contact with each other, the corrugated fin being arranged between the portions of each adjacent pair of hollow bodies corresponding to the respective refrigerant channels thereof and brazed to the hollow bodies.  
   
   
       7 . An evaporator according to  claim 1  which has been subjected to a treatment for imparting hydrophilic properties thereto.  
   
   
       8 . A refrigeration cycle which comprises a compressor, a condenser and an evaporator and wherein a chlorofluorocarbon refrigerant is used, the evaporatorbeing an evaporator according to any one of  claims 1  to  7 .  
   
   
       9 . A vehicle having installed therein a refrigeration cycle according to  claim 8  as a motor vehicle air conditioner.  
   
   
       10 . A process for fabricating an evaporator comprising preparing a flat tube bent zigzag and having a refrigerant passing channel inside thereof and a fin made of a brazing sheet having a brazing material layer on opposite sides thereof, applying a flux to an outer surface of the zigzag flat tube in an amount of 0.05 to 2.8 g/m 2 , disposing the fin between each adjacent pair of straight tube portions of the zigzag flat tube, and brazing the fin to the zigzag flat tube.  
   
   
       11 . A process for fabricating an evaporator according to  claim 10  wherein the flux is applied to the flat tube in an amount of 1 to 2 g/m 2 .  
   
   
       12 . A process for fabricating an evaporator comprising preparing a plurality of straight flat tubes each having a refrigerant passing channel inside thereof and a fin made of a brazing sheet having a brazing material layer on opposite sides thereof, applying a flux to an outer surface of each of the flat tubes in an amount of 0.05 to 2.8 g/m 2 , arranging the plurality of flat tubes in parallel as spaced from one another, disposing the fin between each adjacent pair of flat tubes, and brazing the fin to the flat tubes.  
   
   
       13 . A process for fabricating an evaporator according to  claim 12  wherein the flux is applied to the flat tube in an amount of 1 to 2 g/m 2 .  
   
   
       14 . A process for fabricating an evaporator comprising preparing plates each having a channel-forming bulging portion and a header-forming bulging portion bulging to a greater extent than the channel-forming portion and extending from each of opposite ends of the channel-forming portion and fins from a brazing sheet having a brazing material layer on opposite sides thereof; applying a flux is to opposite surfaces of each of the plates, with the amount of the flux applied to the outer surfaces of both the bulging portions of each plate adjusted to 0.05 to 2.8 g/m 2 ; arranging the plates in stacked pairs each comprising the combination of two plates with openings of the bulging portions of each type opposed to each other in corresponding relation so that the outer surfaces of bottom walls of the header-forming bulging portions of adjacent pairs of plates are in contact with each other, and arranging the fins between the portions of respective adjacent pairs of plates corresponding to the channel-forming bulging portions thereof; brazing the two plates in each pair to each other along peripheral edge portions thereof to form a refrigerant passing hollow body and brazing the fins to respective adjacent pairs of hollow bodies.  
   
   
       15 . A process for fabricating an evaporator according to  claim 14  wherein the flux is applied to the outer surfaces of both the bulging portions of each plate in an amount of 1 to 2 g/m 2 .  
   
   
       16 . A process for fabricating an evaporator according to any one of  claims 10  to  15  wherein the flux is applied as suspended in water containing a binder.  
   
   
       17 . A process for fabricating an evaporator according to any one of  claims 10  to  15  wherein a corrugated fin is used as the fin.  
   
   
       18 . A process for fabricating an evaporator according to any one of  claims 10  to  15  wherein the brazed assembly is finally subjected to a treatment for imparting hydrophilic properties thereto.