Method for drying slurry by using bipolar film evaporator

Abstract

According to the technical scheme, the method for drying the slurry by using the bipolar film evaporator is characterized by comprising the following steps that S1, the SAF slurry is introduced into the vertical film evaporator, steam is introduced into the vertical film evaporator, the slurry is heated, a complex formed by methyl ether and SAF in the slurry is decomposed into light-component compounds such as methanol, ethane, methane and ethylene at high temperature, and when steam is used for heating outside the vertical film evaporator, the light-component compounds are discharged from the vertical film evaporator in a gaseous form along with evaporation of an organic solvent in the slurry; and S2, the slurry heated by the vertical film evaporator enters a horizontal film evaporator through an expansion joint, heat conduction oil is used for heating outside the horizontal film evaporator, and dried powder is sent out after heating. The method has the beneficial effects that the drying efficiency is high, the effect is good, and an organic solvent can be recycled.

Description

technical field [0001] The invention relates to the technical field of slurry drying, in particular to a method for drying slurry with a bipolar thin film evaporator. Background technique [0002] The existing slurry drying methods mainly include spray drying, drum drying, belt drying and thin film evaporator; It is suitable for bulk materials such as calcium carbonate. It needs to be crushed and classified during the process, but it is difficult to install and disassemble, the heat capacity is small, the thermal efficiency is low, and the residence time of materials in the drum varies greatly, which may easily cause partial overheating of materials and affect product quality; Belt type Poor drying airtightness, not suitable for drying organic solvent slurry. [0003] Thin-film evaporators on the market are generally single-stage. Thin-film evaporators, also known as rotary thin-film evaporators, are a new type of evaporator that uses a high-speed rotating scraper to disper...

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Problems solved by technology

[0002] The existing slurry drying methods mainly include spray drying, drum drying, belt drying and thin film evaporator; It is suitable for bulk materials such as calcium carbonate. It needs to be crushed and classified during the process, but it is difficult to install and disassemble, the heat capacity is small, the thermal efficiency is low, and the residence time of materials in the drum varies greatly, which may easily cause partial overheating of materials and affect product quality; Belt type Poor drying airtightness, not suitable for drying of organic solvent slurry

[0003] Thin-film evaporators on the market are generally single-stage. Thin-film evaporators, also known as rotary thin-film evaporators, are a new type of evaporator that uses a high-speed rotating scraper to disperse the material liquid into a uniform film for material concentration. ; At present, thin film evaporators are used to evaporate and dry the slurry in China, but the single-stage thin film evaporator is used because the residence time of the slurry is short, the degree of evaporation is not enough, and the drying effect is poor.

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