Patent ID: 7678341

Claim:
A process for cooling a polypropylene polymerization reactor having four leg jackets comprising: a. pumping a first coolant through a first pair of leg jackets comprising a first leg jacket and a second leg jacket using a first pump; and b. pumping a second coolant through a different pair of leg jackets comprising a third leg jacket and a fourth leg jacket using a second pump, wherein the first pump and the second pump operate in parallel and, wherein the first coolant does not contact the second coolant while inside the leg jackets, wherein step a. comprises: i. pumping the first coolant from the first pump into the first leg jacket; ii. pumping the first coolant from the first leg jacket into the second leg jacket; iii. pumping the first coolant from the second leg jacket into a first heat exchanger, wherein the first heat exchanger comprises a first external loop conduit circulating a first cold external liquid and the first heat exchanger transfers heat from the first coolant to the first cold external cooling liquid; and iv. the first coolant is recirculated via the first pump; and wherein step b. comprises: i. pumping the second coolant from the second pump into the third leg jacket; ii. pumping the second coolant from the third leg jacket into the fourth leg jacket; iii. pumping the second coolant from the fourth leg jacket into a second heat exchanger, wherein the second heat exchanger comprises a second external loop conduit circulating a second cold external liquid and the second heat exchanger transfers heat from the second coolant to the second cold external cooling liquid; and iv. the second coolant is recirculated via the second pump.