Fill fluid thermal management

Abstract

A remote seal assembly for a process transmitter includes a seal body containing a cavity sealed by a diaphragm. The seal body configured to be mounted to a process element containing a process fluid such that a first side of the diaphragm is exposed to the process fluid. A capillary contains a fill fluid that is in fluid communication with the cavity and a second side of the diaphragm. A coupling has a capillary recess and two cavities separated by a second diaphragm. The capillary extends through the capillary recess and connects to the coupling such that the fill fluid in the capillary is in fluid communication with one of the two cavities and the second diaphragm. A thermally conductive element preferably extends continuously along the capillary from the seal body toward the coupling and into the capillary recess without contacting the coupling.

1 - 11 . (canceled) 
     
     
         12 . A remote seal assembly comprising:
 a seal body containing a cavity sealed by a diaphragm, the seal body configured to be mounted to a process element containing a process fluid such that a first side of the diaphragm is exposed to the process fluid; and   a capillary containing a fill fluid is in fluid communication with the cavity and a second side of the diaphragm, the fill fluid comprising one of a low melting temperature fusible metal alloy and a non-mercury based liquid metal.   
     
     
         13 . The remote seal assembly of  claim 12  wherein the fill fluid has a thermal expansion coefficient that is similar to a thermal expansion coefficient of the capillary. 
     
     
         14 . The remote seal assembly of  claim 12  further comprising:
 a transfer body attached to the capillary and having two cavities separated by a second diaphragm, the fill fluid in the capillary being in fluid communication with one of the two cavities and the diaphragm, the second of the two cavities configured to receive a second fill fluid. 
 
     
     
         15 . The remote seal assembly of  claim 14  wherein the capillary has a length that maintains the fill fluid in a liquid state along the entire length of the capillary using heat from the process fluid. 
     
     
         16 . The remote seal assembly of  claim 15  wherein when the temperature of the process fluid is greater than 425 degrees Celsius and less than 800 degrees Celsius, the fill fluid does not vaporize. 
     
     
         17 . The remote seal assembly of  claim 16  wherein when the pressure of the process fluid is between 10 −3  Torr and 10 −8  Torr, the fill fluid does not vaporize. 
     
     
         18 . A remote seal assembly for a process transmitter, the remote seal system comprising:
 a seal body containing a cavity sealed by a diaphragm, the seal body configured to be mounted to a process element containing a process fluid such that a first side of the diaphragm is exposed to the process fluid;   a capillary containing a fill fluid is in fluid communication with the cavity and a second side of the diaphragm;   a housing around the capillary, the housing having a first end made of metal that is fixed to the seal body, a second end made of metal, and an inner section comprising a ceramic that separates the first end from the second end.   
     
     
         19 . The remote seal assembly of  claim 18  wherein the inner section is made of one of Zirconia and Silicon Nitride. 
     
     
         20 . The remote seal assembly of  claim 18  wherein the inner section further comprises a first weld adapter connected to a first end of the ceramic and welded to the first metal end, and a second weld adapter connected to a second end of the ceramic and welded to the second metal end.