Heat Transfer Effects on Dynamic Pressure Response of Pneumatic Vacuum Circuit

In the industrial conveying systems powered by pneumatic ejector, the dynamic pressure response of vacuum circuit is critical to systematic strategic planning. This paper analyzes heat transfer effects on dynamic pressure response. Experiments are carried out in temperature measurement with the stop method. The heat transfer ratio is obtained when the air is entrained from the acrylic chamber under the vacuum condition. The decreasing value of the air temperature inside the vacuum chamber is concerned with ejector flow rate characteristics, the material of the vacuum chamber and heat transfer area. The heat transfer area could be enlarged with copper wires stuffed in the chamber and the isothermal condition is realized. The suction process in such isothermal chamber is then compared with that in the acrylic chamber. The pressure response is faster in the acrylic chamber at the beginning of the suction process but a long time to reach final vacuum degree for temperature recovery.