Synthesis of the control system for the positioning pneumatic drive of shut-off fittings according to the criteria of technological efficiency

Abstract

This paper reports the new design of an experimental bench to study the effectiveness of the positional drive control system of shut-off fittings. For research, the operating modes of the disk flap and ball valve, based on proportional elements with feedback (4–20 mA), were programmatically formed and described. The mathematical model of control over shut-off devices has been analytically described on the example of a disk rotary valve with the possibility of further analysis of individual stages in accordance with the accepted assumptions. The operating control signal is justified with a serial asynchronous interface with an offset operating range of permissible values of –16.0 mA. Separate stages in the operation of the synthesized shut-off fittings based on accepted assumptions have been described. Measurements were performed for disc damper angles of 30°, 60°, 90° by variable value of the pressure control signal (1...4 bar) with sampling of measuring indicators for the control system in real time. The results obtained experimentally confirmed the adequacy of numerical modeling regarding the study of the disk rotary inter-flange valve, as well as preliminary assumptions in the mathematical model. Data were obtained to test the efficiency of controlled shut-off fittings (V-shaped ball valve, disc rotary inter-flange valve) at a sugar factory. The average angle of rotation for a ball is 17.61 degrees; the average value of the vapor temperature after cooling is 130.91 °C (subject to a given value of 130.0 °C). The deviation of the set value is 0.7 %. The average value for the angle of rotation of the disc damper at 43.0 degrees showed the largest deviation of technological parameters of 1.45 %.