Method and Device for Direct-Contact Heat Exchange between a Fouling Liquid and a Cooling Fluid

Abstract

A device and a method for conducting a heat exchange process is disclosed. A direct-contact heat exchanger is provided comprising a process inlet, a coolant inlet, and an interior surface. A process stream is provided to the process inlet to be cooled in the heat exchange process by direct contact with a coolant stream that is provided to the coolant inlet. The coolant stream comprises a liquid or a gas. The heat exchange process comprises a phase change from liquid to gas, a sensible heat transfer, or a combination thereof. The cooling process leads to chemical reactions, solids formation in the bulk phase, or a combination thereof. The use of the direct-contact heat exchanger minimizes such reactions on the interior surface. In this manner, the heat exchange process is conducted.

1 . A method for conducting a heat exchange process comprising:
 providing a direct-contact heat exchanger comprising a process inlet, a coolant inlet, and an interior surface; and,   providing a process stream to the process inlet to be cooled in the heat exchange process by direct contact with a coolant stream that is provided to the coolant inlet, the coolant stream comprising a liquid or a gas, wherein the heat exchange process comprises a phase change from liquid to gas, a sensible heat transfer, or a combination thereof, and the cooling process leads to chemical reactions, solids formation in a bulk phase, or a combination thereof, the use of the direct-contact heat exchanger minimizing such reactions on the interior surface;   
       whereby the heat exchange process is conducted. 
     
     
         2 . The method of  claim 1 , wherein the cooling stream comprises a liquid refrigerant that vaporizes by contact with the feed liquid, a gas refrigerant, or a combination thereof. 
     
     
         3 . The method of  claim 1 , wherein the coolant inlet comprises a pressure-drop device and the cooling stream, comprising a liquid refrigerant, is vaporized by passing through the pressure drop device into the direct-contact heat exchanger, and wherein the pressure-drop device comprises a valve, turbine, nozzle, orifice, or combinations thereof. 
     
     
         4 . The method of  claim 1 , wherein solids formation in the bulk phase produces solid carbon dioxide, solid nitrogen oxide, solid sulfur dioxide, solid nitrogen dioxide, solid sulfur trioxide, solid hydrogen sulfide, solid hydrogen cyanide, water ice, solid hydrocarbons, precipitated salts, or combinations thereof. 
     
     
         5 . The method of  claim 1 , wherein the process stream comprises soot, dust, minerals, microbes, wastewater, acids, bases, immiscible liquids, paper pulp, metal hydrides, solid carbon dioxide, solid nitrogen oxide, solid sulfur dioxide, solid nitrogen dioxide, solid sulfur trioxide, solid hydrogen sulfide, solid hydrogen cyanide, water ice, solid hydrocarbons, precipitated salts, other sulfides, other sulfates, chlorides, or combinations thereof. 
     
     
         6 . The method of  claim 1 , wherein the direct-contact heat exchanger comprises a spray tower, bubble contactor, mechanically agitated tower, or combinations thereof. 
     
     
         7 . The method of  claim 1 , wherein the coolant inlet comprises a gas distributor, bubble plate, sparger, nozzle, or combinations thereof. 
     
     
         8 . The method of  claim 1 , wherein the coolant stream is soluble in the process stream, the process stream is pre-cooled to produce a pre-chilled process stream, and the coolant stream is less soluble in the pre-chilled process stream. 
     
     
         9 . The method of  claim 8 , wherein a temperature of the pre-chilled process stream is near a freezing point of the pre-chilled process stream. 
     
     
         10 . The method of  claim 8 , wherein a portion of the coolant stream is dissolved into the product stream and the process stream is further cooled to near a freezing point of the process stream, causing the coolant stream to become insoluble in the process stream, whereby the process stream is removed. 
     
     
         11 . A direct-contact heat exchanger comprising:
 a process inlet, a coolant inlet, and an interior surface, wherein:
 a process stream is provided to the process inlet to be cooled and a coolant stream is provided to the coolant inlet to cool the process stream by direct contact, the coolant stream comprising a liquid or a gas; 
 the coolant stream cools the process stream by a cooling process comprising a phase change from liquid to gas, a sensible heat transfer, or a combination thereof; 
 the cooling process leads to chemical reactions, solids formation in a bulk phase, or a combination thereof, the use of the direct-contact heat exchanger minimizing such reactions on the interior surface. 
   
     
     
         12 . The device of  claim 11 , wherein the cooling stream comprises a liquid refrigerant that vaporizes by contact with the feed liquid, a gas refrigerant, or a combination thereof. 
     
     
         13 . The device of  claim 11 , wherein the coolant inlet comprises a pressure-drop device and the cooling stream, comprising a liquid refrigerant, is vaporized by passing through the pressure drop device into the direct-contact heat exchanger, and wherein the pressure-drop device comprises a valve, turbine, nozzle, orifice, or combinations thereof. 
     
     
         14 . The device of  claim 11 , wherein solids formation in the bulk phase produces solid carbon dioxide, solid nitrogen oxide, solid sulfur dioxide, solid nitrogen dioxide, solid sulfur trioxide, solid hydrogen sulfide, solid hydrogen cyanide, water ice, solid hydrocarbons, precipitated salts, or combinations thereof. 
     
     
         15 . The device of  claim 11 , wherein the process stream comprises soot, dust, minerals, microbes, solid carbon dioxide, solid nitrogen oxide, solid sulfur dioxide, solid nitrogen dioxide, solid sulfur trioxide, solid hydrogen sulfide, solid hydrogen cyanide, water ice, solid hydrocarbons, precipitated salts, or combinations thereof. 
     
     
         16 . The device of  claim 11 , wherein the direct-contact heat exchanger comprises a spray tower, bubble contactor, sieve tray column, bubble tray column, baffle tray column, mechanically agitated tower, perforated pipe, air-sparged hydrocyclone, nozzle-injected hydrocyclone, or combinations thereof. 
     
     
         17 . The device of  claim 11 , wherein the coolant inlet comprises a gas distributor, bubble plate, sparger, nozzle, or combinations thereof. 
     
     
         18 . The device of  claim 11 , wherein the coolant stream is soluble in the process stream, the process stream is pre-cooled to produce a pre-chilled process stream, and the coolant stream is less soluble in the pre-chilled process stream. 
     
     
         19 . The device of  claim 18 , wherein a temperature of the pre-chilled process stream is near a freezing point of the pre-chilled process stream. 
     
     
         20 . The device of  claim 18 , wherein a portion of the coolant stream is dissolved into the product stream and the process stream is further cooled to near a freezing point of the process stream, causing the coolant stream to become insoluble in the process stream, whereby the process stream is removed.