STUDY ON PNEUMATICS RESPONSES OF RC CIRCUITS ON VACUUM CONDITION

Abstract

Vacuum is frequently utilized for handling systems in factory automation. Because of the negative pressure, the state change of air is different from that of positive pressure systems during charge or discharge. However, pressure and temperature responses in the vacuum condition have not been examined up to now. Therefore, in this study the pressure and temperature responses of RC circuit in the vacuum condition is investigated.
As a result, the research can be summarized as follows:
1) When the positive and negative pressure are compared in the same pressure ratio, it is found that the heat transfer rate is larger in the positive pressure case, because of the larger mixing effect.
2) The temperature responses are determined by the thermal-time constants. Since the negative pressure gets smaller thermal-time constants which concerned the air density, the temperature responses show a smaller variation than those of positive pressure. Therefore, the pressure response is slower in the case of negative pressure.