Device for producing polyvinyl chloride paste resin by micro emulsion suspension process and production method using device

Abstract

The invention relates to a device and method for producing polyvinyl chloride, particularly a device for producing a polyvinyl chloride paste resin by a micro emulsion suspension process and a production method using the device. A polymerization kettle is respectively connected with a discharge chute, a gas receiver and a wastewater collection tank; the wastewater collection tank is connected with a stripping tower; the stripping tower is connected with the polymerization kettle; the discharge chute is respectively connected with a removal tower, the wastewater collection tank and a defoaming mechanism; the removal tower is respectively connected with a latex receiving tank and the gas receiver; the latex receiving tank is connected with a drying tower; and the drying tower is connected with the wastewater collection tank. The production method is controlled by a DCS (distributed control system) and comprises the following steps: raw material preparation, dispersion and premixing, polymerization, discharged material recovery and defoaming, recovery and removal, pulverization, and wastewater continuous treatment. Compared with the prior art, the polymerization kettle has the advantages of large volume and automatic cleaning, does not need to add any chemical defoaming agent for recovery, can discharge the up-to-standard tail gas and implement continuous sewage treatment, greatly enhances the productivity, reduces the labor intensity and lowers the production cost.

Description

technical field [0001] The invention relates to a device and a production method for producing polyvinyl chloride, in particular to a device and a production method for producing polyvinyl chloride paste resin by a microsuspension emulsion method. Background technique [0002] Polyvinyl chloride (PVC) paste resin, as the name implies, is a resin that is mainly used in the form of a paste. People often use this paste as a plasticized paste, which is a unique liquid form of PVC plastic in its unprocessed state. . Paste resin is often prepared by emulsion and microsuspension method, and its reaction equation is: [0003] nCH2=CHCL——→(CH2-CHCL) n. [0004] Due to the fine particle size, the PVC paste resin has a texture like talcum powder and has no fluidity. The polyvinyl chloride paste resin is mixed with a plasticizer and stirred to form a stable suspension, which is made into a PVC paste, or called PVC plasticizer, PVC sol, and it is in this form that people are used to p...

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Problems solved by technology

[0014] 2) Polymerization: The size of the kettle is small, the maximum is 48m3; the stirring is oval and tubular, and the heat capacity of the removal reaction is poor

[0015] 3) Recycling and discharge: it is recycled in the kettle, and the recovery and discharge time is about 4-5 hours, and the production efficiency is low; the recycled monomer will bring out foam containing milk, and a chemical defoamer is required, so adding this defoamer , will affect the downstream processing of paste resin; after recycling and discharging, the manhole cover needs to be opened for each kettle to manually clean the polymerization kettle with high pressure. The cleaning quality is greatly affected by human factors, which is highly dangerous and labor-intensive

[0016] 4) Spray drying and crushing: it is conveyed under negative pressure, and the conveying distance is limited; the drying tower needs manual high-pressure cleaning, and the cleaning quality is greatly affected by human factors, which is highly dangerous and labor-intensive; the VC content in the exhaust gas is low Above 200ppm, does not meet environmental protection requirements

[0018] There are many deficiencies in the traditional process and equipment, which make the production cycle of the device long (1 pot / day), low production capacity (8-10 hours for recycling and discharging and manual cleaning of the pot), and poor product quality (small stirring tank, mechanical Incomplete emulsification, need to add chemical defoamer), high labor intensity (manual operation of cleaning equipment, manual removal of mud cake on filter cloth), and the small volume of key equipment polymerization kettle, resulting in high cost

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