摘要 |
<p>The present invention relates to an improvement in a process for polymerization of polyvinyl chloride, particularly in a suspension polymerization process which provides for removal of residual vinyl chloride monomer, such as by employing a step in which the PVC suspension resin slurry is passed through a column in which it is subjected to a combination of stream and pressure/vacuum conditions. In the improved process of the present invention, the PVC suspension resin slurry feed to the stripping column is first passed through the cold feed side of a spiral hat exchanger, and the PVC suspension slurry outflow from the stripping column is passed through the hot feed side of the heat exchanger, whereby the feed stream to the stripping column acts as a cooling medium for the outlet stream from the stripping column, and the outlet stream from the stripping column serves as a preheating medium for the feed stream.</p> |