In order to prevent the backward flow of piezoelectric pumps, this paper presents\na single-active-chamber piezoelectric membrane pump with multiple passive check valves. Under the\ncondition of a fixed total number of passive check valves, by means of changing the inlet valves and\noutlet valves� configuration, the pumping characteristics in terms of flow rate and backpressure are\nexperimentally investigated. Like the maximum flow rate and backpressure, the testing results show\nthat the optimal frequencies are significantly affected by changes in the number inlet valves and\noutlet valves. The variation ratios of the maximum flow rate and the maximum backpressure are up\nto 66% and less than 20%, respectively. Furthermore, the piezoelectric pump generally demonstrates\nvery similar flow rate and backpressure characteristics when the number of inlet valves in one kind of\nconfiguration is the same as that of outlet valves in another configuration. The comparison indicates\nthat the backflow from the pumping chamber to inlet is basically the same as the backflow from the\noutlet to the pumping chamber. No matter whether the number of inlet valves or the number of outlet\nvalves is increased, the backflow can be effectively reduced. In addition, the back pressure fluctuation\ncan be significantly suppressed with an increase of either inlet valves or outlet valves. It also means\nthat the pump can prevent the backflow more effectively at the cost of power consumption. The pump\nis very suitable for conditions where more accurate flow rates are needed and wear and fatigue of\ncheck valves often occur.
Loading....