Loop reactor for emulsion polymerization

Abstract

A polymerization reactor comprising one or more circulation loops with one or more inlets for raw material, one or more outlets, and a circulation pump for circulating a reactor charge within the circulation loop. A by-pass line for by-passing the circulation pump connects a point of the loop upstream of the pump with a point downstream of the pump.

1 . A system for cleaning a tubular loop reactor and circulation pump, the tubular reactor having at least one circulation loop, the circulation loop having a first end in fluid communication with an inlet side of the circulation pump and a second end in fluid communication with an outlet side of the circulation pump, the system comprising:
 (a) a pigging system comprising at least one pig for cleaning the inside of the tubular reactor, the pigging system configured to allow the at least one pig to by-pass the circulation pump;   (b) a first by-pass line by-passing the circulation pump, said first by-pass line connecting a first point of the tubular loop reactor upstream with a second point of the tubular loop reactor downstream, said first by-pass line configured to form a short loop comprising the pump and a cleaning solvent inlet and a cleaning solvent discharge,   wherein the circulation pump is cleaned by introducing a cleaning solvent into the cleaning solvent inlet and circulating the cleaning solvent around said short loop.   
     
     
         2 . The system of  claim 1 , wherein said pigging system further comprises a second by-pass line having a pig station for storing the at least one pig. 
     
     
         3 . The system of  claim 2 , wherein said at least one pig has a diameter that is about the inner diameter of the tubular loop reactor. 
     
     
         4 . The system of  claim 3 , wherein the tubular loop reactor forms a polymer emulsion which is used to propel said at least one pig through the tubular loop reactor. 
     
     
         5 . The system of  claim 4 , wherein said second by-pass line by-passes the at least one pig around the circulation pump. 
     
     
         6 . The system of  claim 5 , wherein at least a portion of the short loop and/or the by-pass line is provided with jackets connected to a heating medium source. 
     
     
         7 . The system of  claim 1 , wherein at least a portion of the short loop and/or the by-pass line is provided with jackets connected to a heating medium source. 
     
     
         8 . The system of  claim 7 , wherein the heating medium source is heated water. 
     
     
         9 . The system of  claim 8 , wherein said first point of the tubular loop reactor and said second point of the tubular loop reactor are provided with valves to isolate said short loop from the remainder of the tubular loop reactor. 
     
     
         10 . The system of  claim 1 , wherein said first point of the tubular loop reactor and said second point of the tubular loop reactor are provided with valves to isolate said short loop from the remainder of the tubular loop reactor. 
     
     
         11 . A tubular loop reactor comprising:
 (a) at least one circulation loop, the circulation loop having a first end in fluid communication with an inlet side of a circulation pump and a second end in fluid communication with an outlet side of the circulation pump;   (b) a pigging system comprising at least one pig for cleaning the inside of the tubular reactor, the pigging system configured to allow the at least one pig to by-pass the circulation pump;   (c) a first by-pass line by-passing the circulation pump, said first by-pass line connecting a first point of the tubular loop reactor upstream with a second point of the tubular loop reactor downstream, said first by-pass line configured to form a short loop comprising the pump and a cleaning solvent inlet and a cleaning solvent discharge,   wherein the circulation pump is cleaned by introducing a cleaning solvent into the cleaning solvent inlet and circulating the cleaning solvent around said short loop.   
     
     
         12 . The tubular loop reactor of  claim 11 , wherein said pigging system further comprises a second by-pass line having a pig station for storing the at least one pig. 
     
     
         13 . The tubular loop reactor of  claim 12 , wherein said at least one pig has a diameter that is about the inner diameter of the tubular loop reactor. 
     
     
         14 . The tubular loop reactor of  claim 13 , wherein the tubular loop reactor forms a polymer emulsion which is used to propel said at least one pig through the tubular loop reactor. 
     
     
         15 . The tubular loop reactor of  claim 14 , wherein said second by-pass line by-passes the at least one pig around the circulation pump. 
     
     
         16 . The tubular loop reactor of  claim 15 , wherein at least a portion of the short loop and/or the by-pass line is provided with jackets connected to a heating medium source. 
     
     
         17 . The tubular loop reactor of  claim 11 , wherein at least a portion of the short loop and/or the by-pass line is provided with jackets connected to a heating medium source. 
     
     
         18 . The tubular loop reactor of  claim 17 , wherein the heating medium source is heated water. 
     
     
         19 . The tubular loop reactor of  claim 18 , wherein said first point of the tubular loop reactor and said second point of the tubular loop reactor are provided with valves to isolate said short loop from the remainder of the tubular loop reactor. 
     
     
         20 . The tubular loop reactor of  claim 11 , wherein said first point of the tubular loop reactor and said second point of the tubular loop reactor are provided with valves to isolate said short loop from the remainder of the tubular loop reactor. 
     
     
         21 . A method for cleaning a tubular loop reactor and circulation pump, the tubular loop reactor having at least one circulation loop, the circulation loop having a first end in fluid communication with an inlet side of the circulation pump and a second end in fluid communication with an outlet side of the circulation pump, the method comprising:
 (a) using a pigging system having at least one pig to clean a first portion of the tubular loop reactor, the first portion of the tubular loop reactor bypassing the circulation pump so that the at least one pig does not pass through the circulation pump; and   (b) solvent cleaning a second portion of the tubular loop reactor, the second portion forming a short loop including the circulation pump, a first by-pass line connecting a first point of the tubular loop reactor upstream with a second point of the tubular loop reactor downstream, a cleaning solvent inlet and a cleaning solvent discharge,   wherein the second portion of the tubular loop reactor is cleaned by introducing a cleaning solvent into the cleaning solvent inlet and circulating the cleaning solvent around the short loop.   
     
     
         22 . The method of  claim 21 , wherein said pigging system further includes a second by-pass line having a pig station for storing the at least one pig. 
     
     
         23 . The method of  claim 22 , wherein said at least one pig has a diameter that is about the inner diameter of the tubular loop reactor. 
     
     
         24 . The method of  claim 23 , wherein the tubular loop reactor forms a polymer emulsion for propelling the at least one pig through the tubular loop reactor. 
     
     
         25 . The method of  claim 24 , wherein the second by-pass line by-passes the at least one pig around the circulation pump. 
     
     
         26 . The method of  claim 25 , further comprising heating at least a portion of the short loop and/or the by-pass line using jackets connected to a heating medium source. 
     
     
         27 . The method of  claim 26 , further comprising heating at least a portion of the short loop and/or the by-pass line using jackets connected to a heating medium source. 
     
     
         28 . The method of  claim 27 , wherein the heating medium source is heated water. 
     
     
         29 . The method of  claim 28 , wherein the first point of the tubular loop reactor and the second point of the tubular loop reactor are provided with valves to isolate the short loop from the remainder of the tubular loop reactor. 
     
     
         30 . The method of  claim 21 , wherein the first point of the tubular loop reactor and the second point of the tubular loop reactor are provided with valves to isolate the short loop from the remainder of the tubular loop reactor.