Gas-supply apparatus and gas-supply method for realizing efficient transferring and storage and precise metering of gas in double-stage gas-storage cylinder

Abstract

The invention discloses a gas-supply apparatus and a gas-supply method for realizing efficient transferring and storage and precise metering of a gas in a double-stage gas-storage cylinder. The apparatus comprises a first gas-storage cylinder, a booster pump, a second gas-storage cylinder and a high-pressure plunger pump which are in successive connection; a pipeline for connected the first gas-storage cylinder and the booster pump is provided with an air valve and a pressure meter; a pipeline for connected the second gas-storage cylinder and the high-pressure plunger pump is also provided with an air valve and a pressure meter; and the outlet end of the high-pressure plunger pump is provided with a non-return valve. The method comprises: firstly transferring a gas in the first gas-storage cylinder to the second gas-storage cylinder via the booster pump; utilizing the booster pump to improve the gas utilization rate in the first gas-storage cylinder while keeping a constant pressure in the second gas-storage cylinder; and outputting the gas in the second gas-storage cylinder with a constant flow or a constant pressure by using the high-pressure plunger pump. The apparatus and the method help to effectively improve the gas utilization rate in the first gas-storage cylinder and also keep efficient stable transferring and conveying of the gas, are beneficial for stable molding of supercritical-fluid micropore plastic and realizing precise metering of the gas.

Description

technical field [0001] The invention relates to the technical field of continuous extrusion molding of microporous plastics, in particular to a high-efficiency transfer storage and precise metering gas supply device and method for a double-stage gas storage cylinder used in a supercritical fluid microporous plastic molding process. Background technique [0002] Microporous plastics generally refer to cells with a diameter of 0.1-10um and a cell density of 10 9 ~10 15 piece / cm 3 , The material density can be reduced by 5% to 95% compared with the new type of foam before foaming. In recent years, supercritical fluid has become an alternative to traditional chemical development due to its unique advantages such as good solubility for most organic substances, low viscosity, large diffusion coefficient, non-toxic, non-flammable, no solvent residue, cheap and easy to obtain, safe to use, and no pollution to the environment. Ideal physical blowing agent for foaming agents. [0...

AI Technical Summary

Problems solved by technology

[0004] In the current molding process, the supercritical fluid is usually injected by installing a pressure reducing valve at the gas outlet of the gas storage cylinder, and then supplying gas to the molding equipment through the pressure reducing valve, or directly connecting the gas outlet of the gas storage cylinder to the There are common defects in these two methods of gas supply for molding equipment: (1) With the consumption of gas in the gas storage cylinder, the air pressure in the gas storage cylinder will gradually decrease, so the gas delivery efficiency will gradually decrease , affecting the stability of production: (2) when the gas pressure in the gas storage cylinder was lower than the back pressure of the molding equipment, the gas in the gas storage cylinder could not continue to enter the molding equipment, and the gas storage cylinder must be replaced at this time, while There is still a large amount of residual gas in the gas cylinder that has not been fully utilized, which will inevitably cause unnecessary waste and increase production costs

Images