Process to reduce the temperature of a hydrogen and carbon monoxide containing gas and heat exchanger for use in said process

Abstract

Process to reduce the temperature of a hydrogen and carbon monoxide containing gas by contacting the gas with a metal alloy surface having a lower temperature than the temperature of the gas, wherein the metal alloy surface comprises between 0 and 20 wt % iron, between 0 and 5 wt % aluminium, between 0 and 5 wt % silicon, between 20 and 50 wt % chromium and at least 35 wt % nickel, wherein the metal alloy surface maintains it lower temperature than the temperature of the gas by making use of coolant water.

1 . A heat exchanger apparatus suited for lowering the temperature of a hot gas, comprising a vessel having a compartment for cooling water, an inlet for the gas to be cooled, an outlet for cooled gas, an outlet for heated steam and a collecting space for maintaining generated steam and at least one primary evaporator tube positioned in the compartment for cooling water and fluidly connected to the inlet for the gas to be cooled, and at least one steam tube for withdrawal of generated steam from the collecting space for maintaining generated steam and an inlet for fresh water, wherein the interior of the primary evaporator tube material has a metal alloy surface comprising between 0 and 20 wt % iron, between 0 and 5 wt % aluminium, between 0 and 5 wt % silicon, between 20 and 50 wt % chromium and at least 35 wt % nickel, which surface layer is supported by a metal alloy support layer having better mechanical properties than said surface layer. 
   
   
       2 . A heat exchanger according to  claim 1 , wherein the content of chromium in the metal alloy surface is more than 25 wt %. 
   
   
       3 . A heat exchanger according to  claim 2 , wherein the metal alloy surface comprises between 1 and 5 wt % aluminium. 
   
   
       4 . A heat exchanger according to  claim 3 , wherein the metal alloy surface comprises between 1 and 5 wt % silicon. 
   
   
       5 . A heat exchanger according to  claim 4 , wherein the metal alloy surface comprises between 0 and 2 wt % titanium. 
   
   
       6 . A heat exchanger according to  claim 5 , wherein the metal alloy surface layer is applied to the metal alloy support layer by means of a building-up welding method.