A kind of autoclave vacuum pumping process

Abstract

The invention discloses a still kettle vacuumizing technology. After a cement product is subjected to autoclaved curing, the still kettle vacuumizing technology sequentially comprises a step of emptying residual water vapor in a still kettle, including, keeping the still kettle in a sealed state, and emptying residual water vapor in the still kettle within 1-2 hours through vacuumizing; a step of discharging volatilizable moisture in the still kettle, including, volatilizing residual moisture on the surface of the cement product and in the still kettle through vacuumizing and discharging the moisture out of the still kettle; a step of opening a door of the still kettle, including, opening a blow-off valve of the still kettle, and releasing a negative pressure in the still kettle. With the adoption of the still kettle vacuumizing technology, occurrence of cracks of the cement product during the still kettle maintenance can be avoided, and production efficiency can be improved.

Description

technical field [0001] The invention relates to a vacuum-pumping process of an autoclave for cement products, in particular to a vacuum-pumping process of an autoclave for a fiber cement exterior wall board. Background technique [0002] At present, in the production process of cement products, autoclave curing will be carried out on cement products, that is, cement products with a certain initial strength will be put into an autoclave, and then high-temperature and high-pressure steam will be introduced, and the temperature and pressure will be increased according to the process requirements. , Constant pressure and decompression curves, high temperature and high pressure maintenance for products. [0003] The existing autoclaved curing process has the following defects or deficiencies: at the end of the autoclaved curing, the temperature in the kettle is about 100°C, and there is a large amount of water vapor. If the kettle door is opened immediately to quickly discharge t...

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Problems solved by technology

[0003] The existing autoclaved curing process has the following defects or deficiencies: at the end of the autoclaved curing, the temperature in the kettle is about 100°C, and there is a large amount of water vapor. If the kettle door is opened immediately to quickly discharge the heat in the kettle, the cement in the kettle will The temperature of the product will also drop sharply, and the temperature is very uneven

At the same time, it will cause the edge and surface moisture of cement products to volatilize rapidly. Under the joint action of temperature stress and dry shrinkage stress, cement products are prone to produce small cracks or cracks, which will affect the strength and performance of the products, and even cause a large amount of waste products; and if Taking the method of slowly opening the kettle door to gradually reduce the temperature in the kettle or closing the kettle door to cool down naturally will greatly prolong the operation cycle of the autoclave and reduce production efficiency. Moreover, if the temperature and humidity in the autoclave are not properly controlled, the cement Products still have the possibility of cracking

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