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AssigneesInstitut Francais du Petrole, Francois Couillard
InventorsFrancois Couillard, Daniel Durand
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Method and system intended for fine proportioning of fluids injected into a pumping installation, allowing to compensate for non-return valve errors. The system essentially comprises a fluid delivery system including vessels for constituents (A, B, X) that communicate with a pumping unit (1-11) by means of a one-way valve (8) that opens upon suction, and a control unit (PC) that adjusts the respective proportions of the various fluids sucked by acting on the opening time of solenoid valves (EV1 to EVn) associated with the various vessels. As the opening and closing times of the one-way valve are most often unequal in practice, control unit (PC) is suited to cyclically change the order of the control signals applied to the various solenoid valves during the various successive suction stages of each pumping unit so as to compensate on average for the proportioning inequalities due to each one-way valve. Applications: liquid chromatography installations for example.
1) A method for forming a precisely proportioned mixture from various fluid constituents (A, B, . . . , X) contained in vessels, by means of at least one reciprocating pumping unit with each a suction phase and a discharge phase, whose inlet is connected to the various vessels by means of a one-way valve (8) and of solenoid valves (EV1, EV2, . . . , EVn) whose respective opening time intervals (t1 to tn) during the suction phase are selected so as to obtain a mixture with given proportions, characterized in that the order of succession of the respective opening time intervals of the solenoid valves is cyclically changed from one suction phase to the next so as to compensate on average for the proportioning inequalities due to the opening (To) and closing (Tc) time inequalities of each one-way valve (8).
6) A system for forming a precisely proportioned mixture from various fluid constituents (A, B, . . . , X), comprising a fluid delivery system including vessels for constituents (A, B, X) which communicate with a pumping unit (1-11) by means of a one-way valve (8) that opens upon suction, and a control unit (PC) that adjusts the respective proportions of the various fluids sucked by acting on the opening times of solenoid valves associated with the various vessels, characterized in that control unit (PC) is suited to cyclically change, from one suction phase to the next, the order of the control signals applied to the various solenoid valves during the various successive suction phases of each pumping unit so as to compensate on average for the proportioning inequalities due to each one-way valve.
Dependencies are inferred from the claim text.