Supercritical fluid pressure boost metering device

Abstract

The invention discloses a gas pressure boost metering device and particularly relates to a supercritical fluid pressure-boost generating and accurate metering device. The device consists of a filter, four stop valves, three solenoid valves, a pressure regulating valve, three pressure gauges, a gas booster pump, an exhaust valve, a safety valve, three pressure sensors, two supercritical fluid storage tanks, a pilot valve, an electronic pressure controller, a pneumatic control pressure regulating valve, a proportional valve, a bypass valve, an overflow valve, a control unit, a touch screen operation interface, and a pressure pipeline and a communication electric wire or cable which are connected with the components. The device has the advantages that generation and metering are integrated, and the booster pump is driven by gas and is automatically controlled to be switched on and off in a proportion-integration-differentiation (PID) mode; a metering system operates in a bypass backflow mode, and backflow gas is pressurized and recycled; and the fluid in the metering system always flows in a circulating mode, so that pressure jump caused by passage blocking is eliminated.

Description

technical field [0001] The invention relates to a gas pressurization metering device, in particular to a device for supercritical fluid pressurization generation and precise metering delivery, which can be used for polymer microcellular foaming injection molding, etc., which have strict requirements on the injection pressure and flow rate of supercritical fluid. in the required system. Background technique [0002] Microcellular foamed plastics are defined as cells with a cell size below 10 μm and a cell density of 10 9 piece / cm 3 Above, a polymer material with a closed cell structure. The main design idea of ​​the material is: when the size of the cells in the plastic is smaller than the cracks inside the material, the existence of the cells will passivate the original crack tips of the material, which is beneficial to prevent the cracks from expanding under stress, so that the material The mechanical properties are improved. There are two types of blowing agents for mi...

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Problems solved by technology

[0005] According to the deficiencies of the above-mentioned prior art, the present invention proposes a device for supercritical fluid pressurization generation, accurate metering, and stable pressure and flow. A gas-driven booster pump is selected as the main device of the supercritical fluid generation system. The design scheme of the bypass-return high-pressure fluid delivery pipeline was designed to solve the pressure mutation problem of the cut-off delivery pipeline, and the PID closed-loop control strategy was adopted to ensure the constant and stable injection of foaming agent into the barrel in each plasticizing cycle. The stability of the process ensures the stability of the foaming process

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