Composite ceramic device for measuring the temperature of liquids

Abstract

A method of manufacturing a shield assembly for protecting a thermocouple including assembling a first mold including a tubular shield having a cavity for receiving the thermocouple, assembling a second mold having a second tubular shield having a second elongated cavity with an open end, filling the first and second mold cavities with a liquid mix of refractory ceramic material and letting the liquid mix dry and thereafter disassembling the first and second molds to free the first and second tubular shields and curing the refractory ceramic material.

1 - 10 . (canceled) 
     
     
         11 . A method of assembling a thermocouple assembly, the method comprising the steps of:
 providing a first tube having a first elongated cavity and a closed end;   providing a second tube having a second elongated cavity and an open end in communication with the second elongated cavity, the second elongated cavity being sized such as to be able to loosely receive a first portion of the first tube;   inserting a thermocouple into the first elongated cavity such that the thermocouple is received at least in a second portion of the first tube; and   inserting the first tube into the second elongated cavity such that the first portion is retained therewithin and the second portion extends out of the second elongated cavity through the open end.   
     
     
         12 . A method of manufacturing a shield assembly for protecting a thermocouple, the method comprising the steps of:
 assembling a first mould having a first mould cavity forming a first tubular shield having an upper section, a smaller lower section and a first elongated cavity for receiving the thermocouple;   assembling a second mould having a second mould cavity forming a second tubular shield having a second elongated cavity with a first section larger than the upper section and a second section larger than the lower section and smaller than the upper section, the second elongated cavity having an open end in the second section;   filling the first and second mould cavities with a liquid mix of refractory castable ceramic material;   letting the liquid mix dry for an appropriate amount of time;   disassembling the first and second moulds to free the first and second tubular shields;   firing the first and second tubular shields to cure the refractory castable ceramic material; and   inserting the upper section into the first section such that the lower section extends out of the second section through the open end.   
     
     
         13 . The method according to  claim 12 , wherein the refractory castable ceramic material is a silicon carbide with a SiC content of at least 50 percent per weight and a grain size of at most 5 millimeters, and wherein the step of firing the first and second tubular shields is done at a maximal temperature of 1200 degrees Celsius. 
     
     
         14 . The method according to  claim 12  wherein the step of assembling the first mould includes:
 connecting an outer tube to a board such as to define the first mould cavity, the outer tube having a first portion joined to the board and forming the upper section and a second portion forming the lower section; and 
 connecting a rod to the board such that the rod extends along a center line of the outer tube to form the first elongated cavity. 
 
     
     
         15 . The method according to  claim 14 , wherein the rod is made of an upper part and a lower part joined at a connection located within the first mould cavity, the lower part being connected to the board, and the step of pouring the liquid mix into the first mould includes:
 pouring the liquid mix into the first mould until the liquid mix is at a level corresponding to the connection;   detaching the upper part from the lower part; and   filling the first mould with the liquid mix such as to form a closed end in the first elongated cavity.   
     
     
         16 . The method according to  claim 12 , wherein the step of assembling the second mould includes:
 connecting a second outer tube to a second board such as to define the second mould cavity; and   connecting a second outer tube to a second board such that the inner mould extends along a center line of the second outer tube to form the second elongated cavity, the inner mould having a third portion forming the first section and a fourth portion joined to the second board and forming the second section.   
     
     
         17 . The method according to  claim 16 , wherein the step of connecting the inner mould to the second board includes:
 snuggly inserting a first inner tube inside a second inner tube; and   connecting the first inner tube to the second board such that the second inner tub extends within the second mould cavity spaced apart from the board to form the third portion.   
     
     
         18 . The method according to  claim 17 , wherein the first and second inner tubes are made of plastic, and the step of connecting the inner mould to the second board further includes snuggly inserting a third inner tube made of metal inside the first inner tube such as to straighten the inner mould. 
     
     
         19 . The method according to  claim 18 , wherein the step of disassembling the second mould includes:
 removing the third inner tube, the second outer tube and the board;   heating the second tubular shield to at least partially melt the first and second inner tubes without significantly curing the refractory castable ceramic material; and   removing the first and second inner tubes.