| 摘要 |
PURPOSE:To remove unreacted monomer remaining in PVC efficiently, by counter-currently contacting a PVC suspension or emulsion after polymerization with steam in a packed tower. CONSTITUTION:A PVC slurry 1 after a polymerization reaction is led from the bottom 3 of a storage tank 2 through a pump 4 to the lower temperature side inlet 6 of a heat exchanger 5 and heated to 70-100 deg.C by heat exchange with the treated slurry fed from the bottom 14 of a packed tower 7 to the inlet of 16 of a higher temperature feed of a heat exchanger 5. Then, the heated slurry is fed to a nozzle 9 at the upper part of the packed tower 7 operated at a pressure of 300-760mm.Hg, sparged and counter-currently contacted in a packing section with steam fed from a conduit 10 to remove unreacted monomer. Then, the treated slurry combines on the bottom 12 with a portion of the treated slurry fed from an inlet 13 to cool the PVC to 100 deg.C or below and then passes through the bottom 14, a pump 16 and the heat exchanger 5 where it is cooled. On the other hand, the steam containing the unreacted monomer is cooled in a condenser 19 to be condensed and the condensed water is recycled to the top 11 of the tower.
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