Variable heat flux heat exchangers

Abstract

A system for heat exchange is provided in which process material flows through a heat exchanger comprising multiple heat transfer stages and the heating and or cooling power applied to each stage can be modified independently. The system comprises a unitary heat exchanger comprising a heat transfer surface comprising a plurality of elements or zones over which a process material can flow wherein each element or zone has independent means to set or control the level of heating or cooling within that zone.

1 . A unitary heat exchanger comprising a heat transfer surface comprising a plurality of elements or zones over which a process material can flow wherein each element or zone has independent means to set or control the level of heating or cooling within that zone. 
   
   
       2 . A heat exchanger through which a process material is flowing and where the heat transfer surface is broken up into four or more zones. 
   
   
       3 . A heat exchanger through which a process material is flowing and where the heat transfer surface is broken up into ten or more zones. 
   
   
       4 . A heat exchanger according to any of preceding claims which is used to limit temperature shift of the process material at any point within the heat exchanger to within 10% of the temperature shift that would observed if no heating or cooling were applied and where said temperature shift is caused by heat liberated or absorbed within the process conduit of the heat exchanger. 
   
   
       5 . A heat exchanger according to  claim 1  which is constructed as a modular system and that the same size and design of heat transfer plates can be used for different process conduit areas. 
   
   
       6 . A heat exchanger according to  claim 1  where the process fluid flows in a uniform manner. 
   
   
       7 . A heat exchanger according to  claim 1  which has baffles for creating uniform flow. 
   
   
       8 . A heat exchanger according to  claim 1  which can be scaled up by a factor of 10 without substantially altering the uniform flow through the heat exchanger or changing the ratio of heat transfer perimeter to process conduit area. 
   
   
       9 . A heat exchanger according to  claim 1  wherein the volume of flow of the process material is varied through the heat exchanger. 
   
   
       10 . A heat exchanger according to  claim 1  which uses a non-intrusive heat transfer surface. 
   
   
       11 . A heat exchanger according to  claim 1  in which the heat transfer surface is profiled. 
   
   
       12 . A heat exchanger according to  claim 1  which has a process conduit capacity between heat transfer stages which is less than 10% of the process conduit at the heat transfer surface for a given stage. 
   
   
       13 . A heat exchanger according to  claim 1  where the length of the heat transfer conduit between the stages is not longer than the smallest dimension of the heat transfer surface. 
   
   
       14 . A heat exchanger according to  claim 1  where the heat transfer fluid travels in a uniform manner across the full face of the heat transfer surface. 
   
   
       15 . A heat exchanger according to  claim 1  comprising a plate heat exchanger with variable plates. 
   
   
       16 . The use of a heat exchanger according to  claim 1  for controlling the temperature of exothermic or endothermic processes. 
   
   
       17 . The use of a heat exchanger according to  claim 1  for controlling chemical reactions. 
   
   
       18 . The use of a heat exchanger according to  claim 1  for controlling food manufacturing processes. 
   
   
       19 . For the use according to  claim 17  wherein the reaction is a polymerisation reaction. 
   
   
       20 . The use of a heat exchanger according to  claim 1  for refrigeration systems. 
   
   
       21 . The use of a heat exchanger according to  claim 1  as a condenser. 
   
   
       22 . The use according to  claim 21  in batch reactions. 
   
   
       23 . The use of a heat exchanger according to  claim 1  for the condensation of pollutants such as volatile organic compounds from industrial processes. 
   
   
       24 . A process for controlling the temperature of a process material comprising passing the process material over a unitary heat exchanger comprising a heat transfer surface comprising a plurality of elements or zones wherein the level of heating or cooling within each element or zone is independently controlled. 
   
   
       25 . A process according to  claim 24  wherein the heat transfer surface is broken up into ten or more zones. 
   
   
       26 . A process according to  claim 24  wherein the temperature shift of the process material at any point within the heat exchanger is limited to within 10% of the temperature shift that would observed if no heating or cooling were applied and where said temperature shift is caused by heat liberated or absorbed within the process conduit of the heat exchanger. 
   
   
       27 . A process according to  claim 24  wherein the process fluid flows in a uniform manner. 
   
   
       28 . A process according to  claim 24  wherein the volume of flow of the process material is varied through the heat exchanger.