Diethyltoluenediamine combined continuous decompression distillation and purification device

Abstract

The invention relates to a diethyltoluenediamine combined continuous decompression distillation and purification device. The diethyltoluenediamine combined continuous decompression distillation and purification device comprises a distillation kettle and a scraper-type decompression film evaporator, an upper outlet of the distillation kettle is sequentially connected with a condenser and a fine product tank through pipelines, and the condenser or the high-quality product tank is connected with a vacuum pump; a lower outlet of the distillation kettle is connected with a feeding inlet of the scraper-type decompression film evaporator through a pipeline, an upper outlet of the scraper-type decompression film evaporator is connected with the upper part of the distillation kettle through a pipeline, and a lower outlet of the scraper-type decompression film evaporator is connected with a slag tank through a pipeline; the condenser is divided into two stages, and comprises a first condenser and a second condenser, a cold medium inlet of the first condenser is connected with a crude product tank through a pipeline, and a cold medium outlet of the first condenser is connected with a feedinginlet of the distillation kettle; and a cold medium inlet of the second condenser is connected with an outlet of a cooling tower through a pipeline, and a cold medium outlet of the second condenser isconnected with an inlet of the cooling tower. Through the distillation kettle and scraper-type decompression film evaporator combined distillation device, the distillation efficiency and the productpurity can be improved.

Description

technical field [0001] The invention relates to a diethyltoluenediamine combined continuous vacuum distillation purification device, which belongs to the technical field of fine chemicals. Background technique [0002] Diethyltoluenediamine (English name Diethyltoluenediamine) refers to a mixture of two isomers of diethyltoluenediamine, that is, a commercial mixture of two isomers: 3,5-diethyl-2,4-di Aminotoluene (3,5-Diethyl-toluene-2,4-diamine) 76% and 3,5-Diethyl-2,6-diaminotoluene (3,5-Diethyl-toluene-2,6-diamine) 24%, referred to as DETDA. Diethyltoluene diamine is used as chain extender for reaction injection molding polyurethane, curing agent for polyurethane coating, epoxy resin and alkyd resin. Pesticides, dye intermediates, plastics, rubber, oil antioxidants. Diethyltoluene diamine is an aromatic diamine curing agent for polyurethane elastomers and epoxy resins, used for casting, coatings, adhesives, and chain extenders for polyurethane and polyurea elastomers. ...

AI Technical Summary

Problems solved by technology

Refining is all realized by distillation operation at present, in order to obtain diethyltoluenediamine with higher purity and lighter color, it usually needs to be realized through multi-step distillation in the distillation still. This operation has the following defects: 1. Multiple distillation operations have cumbersome steps and low efficiency. 2. Multiple distillations in the still still lead to darkening of the product color. 2. Since the synthesis reaction of diethyltoluenediamine is a polymerization reaction, there are many residues after distillation, which accumulate at the bottom of the still , difficult to clean

[0004] Existing condensers are usually conventional shell-and-tube heat exchangers, which usually include a shell and a number of heat exchange tubes arranged at intervals in it. The inner cavity of the heat exchange tubes is used as the tube side. Between the shell and the shell as the shell side, the hot and cold fluids flow in the tube side and the shell side respectively to realize heat exchange, and the heat medium is condensed; but in actual use, there is a short circuit of the heat exchange medium, that is, some heat exchange medium does not After heat exchange, it flows directly out of the heat exchanger. For example, when the heat exchanger is placed horizontally, the hot steam is mainly distributed in the upper space of the heat exchanger when it goes to the shell side, and the heat exchange area in the lower part is not fully utilized, resulting in insufficient heat exchange. , leading to poor condensation effect; and when the cold medium such as cooling water goes to the shell side, when the flow rate is insufficient, the cooling water only deposits in the lower space of the heat exchanger, and the upper heat exchange area is not fully utilized resulting in insufficient heat exchange , will also lead to poor condensation effect

The main reason for the above defects is that some heat exchange areas are not fully utilized, that is, the effective heat exchange area is low, or the utilization rate of the heat exchange area is low.

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