The invention discloses a control method for the
reaction temperature of
polyvinyl chloride production by a small polymerizing pot DCS; the DCS controls the processes of the polymerizing pot such as temperature increasing, transition, temperature keeping and pot stopping; a steam shut-off value in front of the reaction pot is changed into an adjusting valve; during the
temperature increment stage, the DCS control comprises the sequences as follows: reaction time D value is prearranged, three auxiliary parameter values A, B and C are prearranged, sequential material pouring is carried out, then the steam adjusting valve is opened to specific valve
position control, and the judgment of A and B is carried out by program; the
transition stage is carried out if the B value is achieved; during the
transition stage, the programs closes the steam adjusting valve firstly, and starts a reaction pot jack circulation water valve single circuit, and the judgment of C and D value is carries out by the program; the reaction stage is carried out if the D value is achieved. The relationship of the values A, B, C and D is that A is less than B which is less than C which is less than D; the D value is 52-65 DEG C. Therefore, the
reaction temperature can achieve ideal control standard, thus leading the reaction to be stable and ensuring and optimizing the product quality; simultaneously, the control method has the advantages of convenient and quick operation, overcoming the effects of the artificial factors on the product quality, reducing the accident incidence rate, realizing the
automatic control of the key procedure of aggregated production, and improving the process parameter detection precision and control precision, etc.