Fluid-handling apparatus with corrosion-erosion coating and method of making same

Abstract

Inlet surfaces of a fluid-handling apparatus, such as a heat exchanger, are often prone to corrosion and erosion due to the high velocities of incoming fluid. The present disclosure includes a fluid-handling apparatus with a plurality of wetted surfaces of which a first portion is corrosion-erosion prone and a second portion is non-corrosion-erosion prone. The first portion is coated with a corrosion-erosion coating that is harder than the first portion. Less than all of the wetted surfaces are coated.

1 . A fluid-handling apparatus comprising: 
 an apparatus body including a plurality of wetted surfaces characterized in that a first portion of the wetted surfaces is corrosion-erosion prone and a second portion of the wetted surfaces is non-corrosion-erosion prone;    a corrosion-erosion resistant coating coated on the first portion of the wetted surfaces, wherein the coating is harder than the apparatus body; and    wherein less than all of the wetted surfaces are coated.    
   
   
       2 . The fluid-handling apparatus of  claim 1  wherein the coating includes a metal alloy with a coefficient of thermal expansion sufficiently similar to a coefficient of thermal expansion of the first portion of the wetted surface so that the coating remains attached over a pre-determined temperature range.  
   
   
       3 . The fluid-handling apparatus of  claim 1  wherein the coating includes a metal alloy being galvanic compatible with the first portion of the wetted surfaces.  
   
   
       4 . The fluid handling apparatus of  claim 1  wherein the coating includes a copper-based alloy.  
   
   
       5 . The fluid-handling apparatus of  claim 4  wherein the coating includes copper-nickel alloys including a nickel concentration less than or equal to 40% and greater than or equal to 9%.  
   
   
       6 . The fluid-handling apparatus of  claim 5  wherein the coating includes a nickel concentration of 9-11%.  
   
   
       7 . The fluid-handling apparatus of  claim 4  wherein the coating includes an aluminum bronze alloy including an aluminum concentration equal to or less than 14%, a manganese concentration equal to or less than 2%, a nickel composition equal to or less than 6%, and an iron concentration equal to or less than 5%.  
   
   
       8 . The fluid handling apparatus of  claim 1  wherein the first portion of the wetted surfaces includes at least one liquid inlet surface.  
   
   
       9 . The fluid-handling apparatus of  claim 1  wherein the apparatus includes a heat exchanger.  
   
   
       10 . The fluid-handling apparatus of  claim 9  wherein the heat exchanger includes an air-sea water heat exchanger.  
   
   
       11 . The fluid-handling apparatus of  claim 10  wherein the apparatus body defines a plurality of sea water passages separated from one another by at least one sea water fin and a plurality of air passages separated from one another by at least one air fin oriented substantially perpendicular to the sea water fin, and the sea water passages being separated from the air passages by a plurality of separator plates; and 
 the sea water passages and air passages being fluidly connected to a sea water inlet manifold and a air inlet manifold, respectively.    
   
   
       12 . The fluid-handling apparatus of  claim 11  wherein the first portion of the wetted surfaces includes at least one sea water inlet surface within at least the sea water inlet manifold, and the second portion of the wetted surfaces includes a inner surface of the sea water passages; and 
 the coating includes a metal alloy being galvanic compatible with the first portion of the wetted surfaces and including a coefficient of thermal expansion sufficiently similar to a coefficient of thermal expansion of the first portion of the wetted surface so that the coating remains attached over a pre-determined temperature range, and the coating including either a copper-nickel alloy with 9-40% nickel and an aluminum bronze alloy.    
   
   
       13 . An engine system using sea water as a coolant comprising: 
 an engine; and    a heat exchanger being in fluid communication with the engine, and defining a sea water inlet fluidly connected with a plurality of wetted surfaces, and a first portion of the wetted surfaces being corrosion-erosion prone and a second portion of the wetted surfaces being non-corrosion-erosion prone; a corrosion-erosion resistant coating being coated on the first portion of the wetted surfaces, and wherein the coating is harder than the first portion; and less than all the wetted surfaces are coated.    
   
   
       14 . The engine system of  claim 13  wherein the first portion includes at least one sea water inlet surface of the heat-exchanger.  
   
   
       15 . The engine system of  claim 14  wherein the coating includes a metal alloy being galvanic compatible with the first portion of the wetted surfaces and including a coefficient of thermal expansion sufficiently similar to a coefficient of thermal expansion of the first portion of the wetted surface so that the coating remains attached over a pre-determined temperature range.  
   
   
       16 . The engine system of  claim 15  wherein the coating includes a copper-based alloy.  
   
   
       17 . The engine system of  claim 16  wherein the coating includes a copper-nickel alloy including 9-40% nickel.  
   
   
       18 . A method of making a heat exchanger, comprising the steps of: 
 assembling a plurality of components to include a plurality of wetted surfaces;    distinguishing between corrosion-erosion prone wetted surfaces and non-corrosion-erosion prone wetted surfaces; and    coating the corrosion-erosion prone wetted surfaces with a corrosion-erosion resistant coating being harder than the corrosion-erosion prone wetted surfaces.    
   
   
       19 . The method of  claim 18  wherein the step of coating includes the step of thermal spraying the coating onto the corrosion-erosion prone portion of the wetted surfaces.  
   
   
       20 . The method of  18  wherein the step of coating being performed after the step of assembling.