Control method of one-button discharge of sedimentation tank in polymerization production

Abstract

The invention discloses a control method for one-key discharging of precipitation grooves in polymerization production. According to the control method, particularly, the loop operation from flushingto discharging and the artificial judgement operation, both of which are conducted in the discharging process of the precipitation groove A / the precipitation groove B frequently, are changed to be completed under DCS automatic control; a discharging starting button, a discharging stopping button, a manual operation button, an automatic operation button, a pause button and other relative programsare preset at a central control operation station, the selection between a steam-lifting feeding pump and a backup pump is preset, a discharging check valve and a monomer recycling check valve of theprecipitation groove A / the precipitation groove B are additionally arranged, and the liquid level value, the pressure value and the cleaning time are preset; when the preset logic requirements of adischarging program and a flushing program are met, the next program is automatically initiated, and meanwhile, switching between a manual operation mode and an automatic operation mode can be achieved according to production demands; the program can be initiated or paused or stopped in real time by pushing one button, and after all the programs are completed, the positions of all internal switches and pump valves are reset to initial states; by adopting the control method, operation can reach an ideal control standard better, and meanwhile, the control method has the advantages that operation is convenient and fast, influences caused by human factors are overcome, and optimization and precision control of crucial processes during discharging of the precipitation grooves can be achieved.

Description

technical field [0001] The invention relates to a control method for the discharging operation of a sedimentation tank in the field of automatic control, in particular to a DCS control method for one-key discharging of the sedimentation tank. Background technique [0002] At present, the polyvinyl chloride discharge production process technology in the known polyvinyl chloride production is very mature. The main discharge process is as follows: the discharge of the polymerization kettle includes pumping PVC slurry from the discharge of the polymerization kettle to the precipitation tank A, and then pouring the material from the precipitation tank A to the precipitation tank B, washing the polymerization kettle to remove all resin particles, Recover the unreacted monomer in the polymerization tank and the precipitation tank A / B to the compression condensation process, and then send the slurry to the stripping process. When the sedimentation tank A is discharging to the sedim...

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Problems solved by technology

[0003] 1. At the beginning of pouring, the poured slurry in the sedimentation tank is relatively viscous and often blocked, and the opening time of the discharge valve is slow, and it takes 2 minutes to open, causing the discharge pump to run idly and easily damage the discharge pump;

[0004] 2. The operation of the original sedimentation tank A / B is manual operation, and the judgment of water flushing time, tank pressure and liquid level, and recovery pressure is available during the operation process, and the operation is frequent and the operation intensity is relatively high;

[0005] 3. Most of the sedimentation tanks at this stage have on-site liquid level gauges and remote liquid level gauges, and the remote pressure is displayed twice to the central control. In the process, there are errors in judging the liquid level and pressure, which lead to the flooding of the tank and the phenomenon of slurry exceeding the standard, which affects the qualified rate of indicators and affects production;

[0006] 4. Taking the operation curve or artificially recorded time as the basis for operation control, human control is difficult, there are many mistakes, it is difficult to achieve the purpose of reasonable operation, and there are potential safety hazards in process operation

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