Automatic control method for feeding interval time in polyvinyl chloride resin production

Abstract

The invention discloses an automatic control method for feeding interval time in polyvinyl chloride resin production, wherein the automatic control method is characterized by comprising the followingsteps: 1) presetting a highest liquid level set value a0 and a shortest feeding interval time set value t0 of a discharging tank in a DCS; 2) enabling the DCS to start timing when the raw materials ofthe polymerization kettle are prepared, automatically detecting the feeding interval time t1, and enabling the DCS to automatically detect the liquid level a1 of the discharging tank when dischargingis started after the polymerization reaction is completed; and 3) judging the values of a1 and a0 and t1 and t0, and if a1 is less than or equal to a0 and t1 is more than or equal to t0, sending an alarm prompt that the next kettle material configuration can be carried out by the DCS, simultaneously timing, resetting and re-timing, and starting the next kettle material configuration. According tothe technical scheme provided by the invention, the operation loads of the front procedure and the rear procedure of production are balanced, the product quality is ensured, the labor intensity is reduced, and the production automation level is improved.

Description

technical field [0001] The invention relates to the technical field of automatic control, in particular to an automatic control method for feeding interval time in polyvinyl chloride resin production. Background technique [0002] In the production of polyvinyl chloride resin, after the reaction of the materials in the polymerization tank in the previous process is completed, the latex in the tank is transferred to the discharge tank, and the latex in the discharge tank enters the subsequent process for further drying. It is adjusted according to changes in demand, so the feeding interval of the previous process is not fixed. In order to balance the production of the previous and subsequent processes and stabilize the production load, it is necessary to adjust the feeding interval of the previous process in time according to the amount of dry feed in the subsequent process. [0003] At present, in the production process of polyvinyl chloride resin in the industry, the DCS pr...

AI Technical Summary

Problems solved by technology

[0003] At present, in the production process of polyvinyl chloride resin in the industry, the DCS program control part does not have a program for automatically calculating the feeding interval. The feeding interval of the previous process needs to be calculated manually. Manual calculation is not only time-consuming, but also may be due to the adjustment of the feeding interval. However, there is a situation where the polymerization reactor is stockpiled or insufficient.

Long stacking time makes the latex easy to foam, which in turn causes foaming in the feeding tank and vibrating screen in the previous process, resulting in latex overflowing in the form of foam, resulting in product waste, and increasing the amount of filter press material. Too long stacking time affects the product The quality of the product will have a certain impact on the whiteness and standard paste viscosity of the product

Insufficient material leads to insufficient supply of material in the previous process to the post-drying process. In order to avoid drying shutdown due to lack of material and ensure continuous operation of the drying process, the drying process can only be operated with a small amount of feed, which will affect the overall output.