Flash type evaporator for pulping lignite through hydrothermal treatment and defoaming method

Abstract

The invention relates to a flash type evaporator for pulping lignite through hydrothermal treatment. The flash type evaporator comprises a tubular body, a secondary vapor discharging pipe arranged atthe top of the tubular body and a discharging pipe arranged at the bottom of the tubular body, wherein two charging pipes, which are of eccentric opposite distribution and are used for conveying a coal pulp material to the tubular body, are arranged at the middle part of the tubular body, a rotatable rotating shaft is vertically mounted in the center of the tubular body, a disc turbine which cannot rotate relative to the rotating shaft is mounted at the middle part of the rotating shaft corresponding to the charging pipes, thus, the coal pulp material impacts and rotates the disc turbine, a baffling demister is mounted on the rotating shaft in a manner of being incapable of rotating relative to the rotating shaft above the disc turbine, and a stirrer is mounted on the rotating shaft in a manner of being incapable of rotating relative to the rotating shaft below the disc turbine. According to the flash type evaporator for pulping the lignite through hydrothermal treatment and the defoaming method, by adopting middle opposite charging, the wear to the bottom of the tubular body is avoided; meanwhile, the rotating shaft is driven to rotate through the rotation of the disc turbine, thus, the stirrer at the lower part of the rotating shaft can rotate to play a role in preventing solid-liquid materials in the tubular body from settling blockage; and the baffling demister can rotate along with the rotating shaft to form a dynamic-uniform-distributed demister, thus, defoaming is more effective, and the integration of defoaming and stirring is achieved.

Description

technical field [0001] The invention relates to the technical field of self-evaporators, in particular to a self-evaporator and a defoaming method for lignite hydrothermal treatment pulping. Background technique [0002] In lignite hydrothermal treatment pulping technology, the coal slurry after hydrothermal treatment needs to be flashed through a multi-stage self-evaporator, and the secondary steam is recovered by reducing the pressure and used for preheating the raw coal slurry. However, the existing self-evaporator is directly used It is not ideal enough in lignite hydrothermal treatment pulping process. [0003] Self-evaporator technology is widely used in both the chemical industry and the alumina industry. In the chemical industry, self-evaporators for liquids are more common, while self-evaporators for solid-liquid mixtures are rare. In the alumina industry, the material used in the self-evaporator of the Bayer method dissolution section is a solid-liquid mixture, bu...

AI Technical Summary

Problems solved by technology

In the alumina industry, the material used in the self-evaporator of the Bayer method dissolution section is a solid-liquid mixture, but there are many problems in actual use: 1. There is no stirring inside the self-evaporator, which leads to the settlement of the internal solid-liquid material, resulting in easy blockage of the discharge pipe , so as to stop the treatment; 2. The existing self-evaporators are all medium and high pressure equipment. Due to the difficulty of processing, there are few internal defoaming sieve plates, which leads to poor defoaming effect and frequent occurrence of steam carrying material, which leads to the current There is a demister installed on the upper part of the self-evaporator, but the installation of the demister not only increases the installation space and floor area, but also increases the equipment investment; 3. Most of the existing self-evaporators are fed vertically from the top, and the material The impact on the bottom of the self-evaporator is relatively large, resulting in wear-through of the bottom, etc., and it is necessary to install anti-wear liners, etc., which increases investment and processing difficulty

The umbrella-shaped baffle installed at the bottom is more reasonable than the original liner, but it still does not fundamentally solve the problem of material wear on the bottom of the tank

[0006] Patent CN101579579B discloses a method for multi-stage defoaming of an evaporator. In this patent, a multi-stage demister is installed on the top of the self-evaporator, which effectively solves the problem of material entrainment. However, the length of the multi-stage demister is relatively large, which will Occupies a large installation space, but also increases equipment investment

[0007] The above three patents are all types of self-evaporators currently used in the alumina industry. Although they have alleviated some of the problems in the application of the above-mentioned self-evaporators to a certain extent, they have not completely solved the above problems, and there is no stirring device inside, so There are still many problems when it is applied to lignite hydrothermal treatment pulping process

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