A kind of nitrogen airtight cycle pva powder making method

Abstract

The invention relates to a nitrogen gas sealed circulating PVA powder processing method. The method comprises the following steps: (1) after a PVA polymer or resin passes through a rotary gas locking device I, the PVA polymer or resin is continuously and uniformly added into a crusher to obtain PVA particles; (2) nitrogen gas is conveyed into the crusher, the PVA particles are conveyed into a grading device to be graded to obtain large-particle PVA and nitrogen gas containing qualified PVA particles, and the large-particle PVA falls into the crusher to be crushed again; (3) the nitrogen gas containing the qualified PVA particles enters a cloth bag dust remover to be subjected to gas-solid separation to obtain fine powder and separated nitrogen gas, and the fine powder passes through a rotary gas locking device II to enter a stock bin; (4) the separated nitrogen gas enters a condenser to be subjected to indirect cooling with a cooling medium to obtain condensed nitrogen gas and condensate water; and (5) the condensed nitrogen gas is boosted by a circulating draught fan and then enters the crusher to be circularly utilized in a sealed manner. The nitrogen gas sealed circulating PVA powder processing method has the characteristics of safety and low energy consumption.

Description

technical field [0001] The invention relates to the technical field of safety, environmental protection and energy saving of PVA powder making, in particular to a method for making PVA powder with a nitrogen closed cycle. Background technique [0002] The traditional PVA powder making method means that PVA is continuously and evenly added into the crusher through the rotary air locker, and the coarse material is crushed and enters the air flow conveying system, and is conveyed to the dust collector for gas-solid separation, the air is vented, and the solid particles enter the silo. But the method exists: [0003] ① PVA is a combustible dust, and there is a potential safety hazard of dust explosion in air transportation. [0004] ②PVA is an organic polymer material. After being crushed, it contains a large amount of organic fine powder. When it is in contact with air during transportation, it is easy to burn and even cause a dust explosion. [0005] ③PVA is transported by a...

AI Technical Summary

Problems solved by technology

[0003] ①PVA is a combustible dust, and there is a potential safety hazard of dust explosion in air transportation

[0004] ②PVA is an organic polymer material. After being crushed, it contains a large amount of organic fine powder. When it is in contact with air during transportation, it is easy to burn and even cause dust explosion.

[0005] ③PVA is transported by air, which is greatly affected by temperature

For example, when running in summer, two crushers are needed, and the energy consumption is relatively high

[0006] ④PVA is transported in an open air circuit, and the exhaust gas is emptied after dust removal, which is easy to cause dust pollution

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