DCS system operation optimization method applied to suspension polyvinyl chloride production

Abstract

The invention provides a DCS system operation optimization method applied to suspension polyvinyl chloride production. The method comprises steps that for polymerization kettle program selection, whena polymerization kettle is subjected to a certain program, only the polymerization kettle satisfying the conditions is selected; a control valve for water injection in the polymerization kettle in the process, a control valve for stirring the mechanical seal water and a pressure sensor of the polymerization kettle are interlocked; before start of the initiator feeding program, the polymerizationkettle is determined and confirmed and then started. The method is advantaged in that after an operator clicks Start on a certain program, after the DCS passes automatic identification, only the polymerization kettle capable of performing the program pops on the page, for example, wall coating, material feeding and reaction kettles do not appear on a selection page of the discharge program, duringnormal production, the polymerization kettle that satisfies the conditions of any program is only one, that is, after Start of the certain program is clicked, only the one that satisfies the conditions pops up on the DCS page, and accidents caused by operator selection errors are avoided.

Description

technical field [0001] The invention belongs to the field of organic chemistry, and in particular relates to a production control method of polyvinyl chloride resin. Background technique [0002] In the current chemical industry, the production methods of polyvinyl chloride mainly include suspension polymerization, bulk polymerization, suspension polymerization, and solution polymerization. Among them, the suspension polymerization method is to add deionized water and dispersant to the polymerization kettle, then add the initiator, seal the polymerization kettle and seal the stirring device with water, add vinyl chloride monomer and start to heat up and stir. After the polymerization is completed, the unreacted monomer and slurry are extracted for stripping, and the vinyl chloride monomer is recovered. The slurry after the gas is extracted is centrifuged, dried, and sieved to obtain the product. For the suspension polymerization production process, the control system most u...

AI Technical Summary

Problems solved by technology

For a production line with multiple polymerization kettles in the existing DCS, if you click "Start", the page will pop up a selection button for multiple kettles, and the operator must select a certain kettle before starting the program, and there is a risk of human selection errors , likely to cause an accident

[0003] In addition, the existing DCS system still has insufficient control effects on improving safety and product quality

The opening pressure of the safety valve of the polymerization kettle is 1.95MPa, and the pressure of the sealing water of the stirring device is about 2.1MPa. During the operation of the polymerization kettle, it is very likely that the kettle will be full and safely vented due to continuous water injection.

In the process of controlling the polymerization, adding the initiator is an automatic operation, but if there is a quality problem with the raw material or a deviation in the input amount, the dispersion system is likely to be damaged or not perfect. If the operator does not find the abnormality in time, after the initiator is automatically added , the quality of the product produced by the still reaction will be affected to varying degrees

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