Air-lift DTB evaporative crystallizer

Abstract

The invention relates to the technical field of industrial crystallization, and discloses an air-lift DTB evaporative crystallizer. The air-lift DTB evaporative crystallizer comprises a crystallizer,a guide cylinder, a supersaturated feed liquid inlet, a solution outlet, a solution outlet, a steam outlet and an elutriation column, and the guide cylinder extends into the crystallizer. Compared tothe prior art, gases are introduced into the crystallizer through an inflation stirring device to drive feed liquid to rotate and rise, the stirring of the feed liquid can be increased by increasing the circulation rate of the gases, the flow rate of the feed liquid is increased, solute nucleation and crystal growth efficiency are improved, the mechanical collision of crystals is effectively reduced, crystal damaging is reduced, and the crystal quality is improved; and moreover, due to the gases flow out from the interior of the inflation stirring device, so that the contact point and time ofthe feed liquid and the inner wall of the inflation stirring device can be reduced, the formation rate of crystal scales on the inner wall of the inflation stirring device can be effectively reduced,the maintenance frequency of an instrument is reduced, and the maintenance cost is reduced.

Description

technical field [0001] The invention relates to the technical field of industrial crystallization, in particular to an air-lift DTB evaporation crystallizer. Background technique [0002] DTB evaporative crystallizer 1 is a fine slurry circulating crystallizer 1, as attached figure 1 , the supersaturated feed liquid flows into the crystallizer 1 from the supersaturated feed liquid inlet 5, and is sent to the liquid surface by the slowly rotating stirring device 4 along the cylindrical baffle 3, and the supersaturated feed liquid evaporates and cools on the liquid surface to reach the supersaturated state , in which part of the solute is deposited on the surface of the suspended particles to make the crystal grow, and at the same time a settlement zone is formed between the crystallizer 1 and the draft tube 2, and the large particles settle in the settlement zone, while the small particles follow the mother liquor from the solution outlet 6 Discharge into the circulation pip...

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Problems solved by technology

[0003] When the stirring device 4 stirs the feed liquid, when the rotation rate is slow, the stirring effect on the feed liquid is not good, and the feed liquid cannot be raised and the flow rate of the feed liquid cannot be accelerated. When the stirring device 4 rotates at a faster speed, its rotation The blades cause shear collision to the crystals in the feed liquid, causing the crystals in the feed liquid to break, which reduces the quality of the crystals. At the same time, during the stirring process, the feed liquid collides with the inner wall of the cylindrical baffle 3, increasing the contact between the feed liquid and the cylinder. The contact area of ​​the cylindrical baffle 3 makes the inner wall of the cylindrical baffle 3 very easy to form crystal scale, resulting in the reduction of the internal space of the cylindrical baffle 3, which greatly reduces the flow of the material liquid.

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