Device and method for recycling waste water for washing plate frame for pentaerythritol

Abstract

The invention provides a device and a method for recycling waste water for washing a plate frame for pentaerythritol. The treatment method comprises the following steps that 1), the waste water for washing the filter plate frame is collected and then introduced into a dissolving kettle, the dissolving kettle is kept at 80-100 DEG C, liquid in the dissolving kettle enters the filter plate frame through a pump, the filter plate frame is washed repeatedly by the liquid, circulation is formed between the filter plate frame and the dissolving kettle, the concentration of pentaerythritol in the waste water is increased, and the concentration of pentaerythritol in the liquid in the dissolving kettle is detected; and 2), when the mass concentration of pentaerythritol reaches 5-20%, a liquid material is introduced into a hydrolysis kettle through a dissolving kettle pump, acid is added to the hydrolysis kettle, stirring is conducted, the temperature rises to 90-110 DEG C and is kept for 1-2h, methanol and methanal are discharged, and the rest of liquid is subjected to pentaerythritol separation and purification. According to the device and the method, the waste water for washing the plate frame in pentaerythritol production is collected, and then hydrolyzed and recycled after reaching a certain concentration, and no secondary pollution is generated.

Description

technical field [0001] The invention relates to a device and method for recycling waste water from pentaerythritol washing plate frames. Background technique [0002] An important step in the existing production of pentaerythritol is filtration, which includes primary mother liquor filtration, secondary mother liquor filtration, clear liquid filtration, etc. After filtration, the filtrate and filter cake are processed in the next process, but there are many solids on the filter cloth The material will affect the next filtration speed and accuracy. It is necessary to rinse the filter cloth with a large amount of hot water before using it again. Due to the low concentration of pentaerythritol and high impurities such as acetal and pentaerythritol methyl ether in the waste water after cleaning the filter cloth, the direct recovery often outweighs the gain and affects the production of pentaerythritol, resulting in a decline in the quality of pentaerythritol and an increase in t...

AI Technical Summary

Problems solved by technology

[0002] An important step in the existing production of pentaerythritol is filtration, which includes primary mother liquor filtration, secondary mother liquor filtration, clear liquid filtration, etc. After filtration, the filtrate and filter cake are processed in the next process, but there are many solids on the filter cloth materials, affecting the next filtration speed and accuracy, it is necessary to rinse the filter cloth with a large amount of hot water before using it again

Due to the low concentration of pentaerythritol and high impurities such as acetal and pentaerythritol methyl ether in the waste water after cleaning the filter cloth, the direct recovery often outweighs the gain and affects the production of pentaerythritol, resulting in a decline in the quality of pentaerythritol and an increase in the consumption of steam. Manufacturers directly discharge and treat it, which affects environmental protection on the one hand, and causes high production costs of pentaerythritol on the other hand. Therefore, how to effectively treat this wastewater can not only effectively reduce the pressure on environmental protection, but also generate certain economic benefits.

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