摘要 |
The invention provides a pulsation free pump which includes a plurality of hydraulic diaphragm pumps, a plurality of plungers corresponding to the hydraulic diaphragm pumps, each of the plungers performing a reciprocal movement which provides a pumping cycle operation of corresponding one of the plurality of hydraulic diaphragm pumps and an adjustable exhaust differential pressure regulating valve. Each of the pumping cycles includes a discharge process and a subsequent suction process. A controller is provided for controlling reciprocal movements of the plungers in association with each other at a predetermined difference in phase of the pumping cycle. The controller controls the reciprocal movement of each of the plungers so as to set a preliminary pressure-rising process just before the discharge process so that a discharge flow rate of each of the diaphragm pumps is initiated to increase without any time delay when the pumping cycle enters into the discharge process so that a total discharge flow rate defined by the sum of the discharge flow rates of all of the plungers is kept constant and free of any substantial pulsation.
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