Reactor liquid cooldown method

Abstract

A reactor liquid cool down method is provided. The method includes obtaining a warm recycle stream ( 102 ) from a reactor ( 101 ) and compressing the warm recycle stream ( 102 ), thereby producing a compressed warm recycle stream ( 104 ); mixing a compressed warm recycle stream ( 104 ) with a controlled liquid cryogen stream ( 110 ) in a stainless steel mixing zone ( 107 ), thereby producing a cool recycle stream ( 112 ), wherein the cool recycle stream has a mean fluid temperature, monitoring the mean fluid temperature and comparing the mean fluid temperature to a predetermined control valve set point, thereby defining a temperature deviation; modulating a temperature control valve ( 109 ) to vary the controlled liquid cryogen stream ( 110 ) in order to produce a temperature deviation that is less than a predetermined value, and returning the cool recycle stream ( 112 ) to the reactor ( 101 ).

What is claimed is: 
     
         1 . A reactor liquid cool down method, comprising;
 obtaining a warm recycle stream from a reactor and compressing the warm recycle stream, thereby producing a compressed warm recycle stream,   mixing the compressed warm recycle stream with a controlled liquid cryogen stream in a mixing zone, thereby producing a cool recycle stream , wherein the cool recycle stream has a mean fluid temperature,   monitoring the mean fluid temperature and comparing the mean fluid temperature to a predetermined control valve set point, thereby defining a temperature deviation,   modulating a temperature control valve to vary the controlled liquid cryogen stream in order to produce a temperature deviation that is less than a predetermined value, and   returning the cool recycle stream to the reactor.   
     
     
         2 . The reactor liquid cool down method of  claim 1 , further comprising;
 monitoring a first mean fluid temperature of the warm recycle stream,   closing the temperature control valve, closing a first valve, a closing second valve, and opening a bypass valve if the first mean fluid temperature is less than a predetermined minimum temperature,   
       wherein the first valve and the second valve isolate the stainless steel mixing zone, and 
       wherein the bypass valve allows the warm recycle stream to return to the reactor. 
     
     
         3 . The reactor liquid cool down method of  claim 1 , wherein the mixing zone is stainless steel. 
     
     
         4 . The reactor liquid cool down method of  claim 1 , wherein the mean fluid temperature is monitored by temperature indicators. 
     
     
         5 . The reactor liquid cool down method of  claim 4 , further comprising at least three temperature indicators, wherein a two out of three voting protocol is utilized. 
     
     
         6 . The reactor liquid cool down method of  claim 1 , wherein the liquid cryogen is liquid nitrogen.