Device and method for producing alpha-semi-hydrated gypsum by utilizing industrial by-product gypsum by means of pneumatic autoclave

Abstract

The invention relates to a device and a method for producing alpha-semi-hydrated gypsum by utilizing industrial by-product gypsum by means of pneumatic autoclave. The device comprises a vertical type autoclaved kettle, a steam pumping system and a high pressure pneumatic system, wherein high-pressure hot air passes through an exhaustion device to blow materials in the vertical type autoclaved kettle upwards by utilizing the high pressure pneumatic system, so that the materials are in a loosening state and an exhaustion channel is supplied for water vapor of the materials; steam can be introduced intermittently into a pneumatic pipe in an autoclaving process so as to prevent the compaction of desulfurization gypsum inside the autoclaved kettle. Water vapor is pumped away by utilizing the steam pumping system so that the aim of drying the alpha-semi-hydrated gypsum produced by means of autoclaving is fulfilled. According to the device and the method, the advantages of a hydrothermal method and the vertical type autoclaved kettle are combined, the industrial by-product gypsum belonging to the industrial wastes can be comprehensively utilized, and the wastes are turned into treasures; a mechanical part of the device is eliminated, so that the power-saving property and mechanical loss are realized, and the investment of the whole production line is reduced.

Description

technical field [0001] The invention relates to the production of α-hemihydrate gypsum, in particular to a device and a method for producing α-hemihydrate gypsum directly by autoclaving the industrial by-product gypsum. Background technique [0002] At present, there are two production processes for α-hemihydrate gypsum: one is the hydrothermal method, which is characterized by using powdered dihydrate gypsum (industrial by-product gypsum also belongs to dihydrate gypsum) as raw material, using "reactor" As one of the production equipment, the water in the kettle is heated by the wall of the kettle, and then the heat energy is transferred to the gypsum material (powder) through the high-temperature water for reaction (decrystallization water becomes hemihydrate gypsum), of which the material accounts for 30% of the total volume, and other It is 70% water, and continuous stirring is required during the reaction process to make the temperature of the hot water in the react...

AI Technical Summary

Problems solved by technology

[0002] At present, there are two production processes for α-hemihydrate gypsum: one is the hydrothermal method, which is characterized by using powdered dihydrate gypsum (industrial by-product gypsum also belongs to dihydrate gypsum) as raw material, using "reactor" As one of the production equipment, the water in the kettle is heated by the wall of the kettle, and then the heat energy is transferred to the gypsum material (powder) through the high-temperature water for reaction (decrystallization water becomes hemihydrate gypsum), of which the material accounts for 30% of the total volume, and other It is 70% water, and continuous stirring is required during the reaction process to make the temperature of the hot water in the reactor uniform, quickly enter the water from the wall of the kettle, and make the material heated evenly; this process has the following disadvantages: (1) The product is dry In addition, additional equipment and processes are required, and the equipment used for drying is complex (requires double drying) and the investment is very large; (2) The reaction kettle needs a mechanical stirring device with a high-pressure dynamic seal, which is easily damaged, and the mechanical stirring device is also It is easy to be damaged; (3) It needs to heat more than 3 times the water of the material, which greatly increases the drying energy consumption; and the advantage of this process is that it uses powdered dihydrate gypsum as the raw material, and the product quality is better when water is used as the heat medium

[0003] The other is the autoclave method, and the total equipment investment is only one-tenth of that of the "hydrothermal method"; however, it is necessary to use block gypsum as the raw material and "autoclave" as the production equipment, which can make the gypsum react and dry. It is carried out in the same equipment; it directly feeds steam from the top to heat the gypsum raw material. The autoclave used is divided into two types: horizontal and vertical. It is very cumbersome and the drying efficiency is low: while the feeding port of the vertical autoclave is at the top and the discharge port is at the bottom, the loading and unloading of raw materials is simple and convenient, and it is integrated with autoclave drying, without mechanical parts, and the process operation and equipment are simple; But when adopting the industrial by-product gypsum as raw material to produce α-hemihydrate gypsum, because the industrial by-product gypsum is all powdery, if still adopt the production device and the processing method of the vertical autoclave, then the powdery industrial by-product When the gypsum is produced, it will accumulate densely, and the autoclaved and powdered α-hemihydrate gypsum cannot be completely dried, especially the autoclaved and powdered α-hemihydrate gypsum in the center cannot be dried

Therefore, the industrial by-product gypsum cannot be processed into α-hemihydrate gypsum by using the traditional vertical autoclave and the corresponding production process

Images