Method of making a condensing heat exchanger by direct extrusion coating of afilm

Abstract

A thermoplastic polymer film is directly extruded onto the heated surface of a metal condensing heat exchanger. Any thermoplastic polymer capable of being adhered to the metal surface of the condensing heat exchanger can be utilized. Preferably, the thermoplastic polymer is a polyester, a polyolefin with an added maleate or tackifier to ensure adhesion, polyetherimide, polyethersulfone, polysufone or polyimide. The thermoplastic film must be resistant to the conditions of the condensing heat exchanger, such as the high temperature flue vent gases and the acidic condensate formed from condensation.

1 - 26 . (cancelled)  
   
   
       27 . A heat exchanger component comprising: 
 a plurality of metal condensing flow passages each having a surface; and    a film formed from a melted polyester applied directly to the surface of the plurality of metal condensing flow passages.    
   
   
       28 . The heat exchanger component as recited in  claim 27  wherein the melted polyester is one of polybutylene terephthalate and polyethylene terephthalate.  
   
   
       29 . The heat exchanger component as recited in  claim 27  wherein the surface of the plurality of metal condensing flow passages are heated by a heat exchanger heater when the melted polyester is applied directly to the surface.  
   
   
       30 . The heat exchanger component as recited in  claim 27  further including a roller assembly that adheres the film to the surface of the plurality of metal condensing flow passages.  
   
   
       31 . The heat exchanger component as recited in  claim 27  further including a polymer heater, wherein a plurality of polyester pellets are melted by the polymer heater to form the melted polyester.  
   
   
       32 . The heat exchanger component as recited in  claim 27  wherein the surface of the plurality of metal condensing flow passages is substantially flat.  
   
   
       33 . The heat exchanger component as recited in  claim 27  wherein the film has a thickness between approximately 0.2 and 10 mils.  
   
   
       34 . The heat exchanger component as recited in  claim 27  wherein the heat exchanger component is a condensing heat exchanger.  
   
   
       35 . The heat exchanger component as recited in  claim 27  wherein the heat exchanger component exchanges heat between a flue gas and air.  
   
   
       36 . A heat exchanger component comprising: 
 a plurality of metal condensing flow passages having a surface; and    a film formed from a melted polymer applied directly to the surface of the plurality of metal condensing flow passages, wherein the melted polymer is one of polyetherimide, polyethersulfone, polysufone and polyimide.    
   
   
       37 . The heat exchanger component as recited in  claim 36  wherein the surface of the plurality of metal condensing flow passages are heated by a heat exchanger heater when the melted polymer is applied directly to the surface.  
   
   
       38 . The heat exchanger component as recited in  claim 36  further including a roller assembly that adheres the film to the surface of the plurality of metal condensing flow passages.  
   
   
       39 . The heat exchanger component as recited in  claim 36  further including a polymer heater, wherein a plurality of polymer pellets are melted by the polymer heater to form the melted polymer.  
   
   
       40 . The heat exchanger component as recited in  claim 36  wherein the surface of the plurality of metal condensing flow passages is substantially flat.  
   
   
       41 . The heat exchanger component as recited in  claim 36  wherein the film has a thickness between approximately 0.2 and 10 mils.  
   
   
       42 . The heat exchanger component as recited in  claim 36  wherein the heat exchanger component is a condensing heat exchanger.  
   
   
       43 . The heat exchanger component as recited in  claim 36  wherein the heat exchanger component exchanges heat between a flue gas and air.  
   
   
       44 . An apparatus for applying a film to a heat exchanger component comprising: 
 a heat exchanger heater to heat a surface of a heat exchanger component;    a polymer heater to heat a plurality of polymer pellets to form a melted polymer, wherein the melted polymer is applied directly to the surface of the heat exchanger component that is heated by the heat exchanger heater; and    a roller assembly to press the melted polymer onto the surface of the heat exchanger component to form a film.    
   
   
       45 . The apparatus as recited in  claim 44  wherein the melted polymer is polyester.  
   
   
       46 . The apparatus as recited in  claim 44  wherein the melted polymer is one of polyetherimide, polyethersulfone, polysufone and polyimide.