DMF (dimethyl formamide) recovery device and method in production of synthetic leather

Abstract

The invention discloses a DMF (dimethyl formamide) recovery device and method in production of synthetic leather. The device comprises a first-level concentration tower, a second-level concentration tower, a rectifying tower and a deacidification tower, wherein the four towers are all provided with a reboiler; a gas outlet at the top of the rectifying tower is connected with the reboiler of the second-level concentration tower through a pipeline; a gas outlet at the top of the second-level concentration tower is connected with the reboiler of the first-level concentration tower through a pipeline; the rectifying tower is connected with a feed device; the feed device comprises a gas-liquid separator arranged on the rectifying tower, a flash tank connected with the gas-liquid separator and a feed heater connected with the flash tank; and a discharge port of the second-level concentration tower is connected with the flash tank through a discharge pump. According to the invention, since the gas-liquid separator performs gas-liquid separation during the feed of the rectifying tower, the liquid droplets carried by the ascending gas and the gas carried by the descending liquid are greatly reduced, the recovery rate of DMF is improved, and the recovery is more thorough; and meanwhile, the production cost of the synthetic leather can be lowered, and more economic benefits are brought to enterprises.

Description

technical field [0001] The invention relates to the technical field of synthetic leather production, in particular to a DMF recovery device and a recovery method in the production of synthetic leather. Background technique [0002] At present, the DMF recovery device in the existing synthetic leather production generally includes a primary concentration tower, a secondary concentration tower, a rectification tower, and a deacidification tower. The four towers are all equipped with a reboiler. Connected to the reboiler of the secondary concentration tower by pipelines, the gas outlet of the secondary concentration tower is connected to the reboiler of the primary concentration tower by pipelines, and the discharge port of the primary concentration tower is connected to the The reboiler of the secondary concentration tower, the outlet of the secondary concentration tower is connected to the reboiler of the rectification tower by a pipeline, and the outlet of the rectification ...

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Problems solved by technology

[0002] At present, the DMF recovery device in the existing synthetic leather production generally includes a primary concentration tower, a secondary concentration tower, a rectification tower, and a deacidification tower. The four towers are all equipped with a reboiler. Connected to the reboiler of the secondary concentration tower by pipelines, the gas outlet of the secondary concentration tower is connected to the reboiler of the primary concentration tower by pipelines, and the discharge port of the primary concentration tower is connected to the The reboiler of the secondary concentration tower, the outlet of the secondary concentration tower is connected to the reboiler of the rectification tower by a pipeline, and the outlet of the rectification tower is connected to the reboiler of the deacidification tower by a pipeline When rectifying the recovery device with this structure, its feed is directly discharged into the reboiler without gas-liquid separation. The rising gas carries a large amount of liquid droplets, and the descending liquid also carries a large amount of gas. , the DMF recovery rate is low, the recovery is not complete, and the production cost of synthetic leather is also increased

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