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CN-224220764-U - Thermal coupling energy-saving tower of NMP four-tower rectifying system

CN224220764UCN 224220764 UCN224220764 UCN 224220764UCN-224220764-U

Abstract

The utility model discloses a thermal coupling energy-saving tower of an NMP four-tower rectifying system, which relates to the technical field of four-tower rectification and comprises a first rectifying tower, a second rectifying tower, a third rectifying tower and a fourth rectifying tower which are sequentially connected in series, wherein the top of the first rectifying tower is provided with a first condenser, the bottom of the first rectifying tower is in thermal coupling connection with the middle part of the second rectifying tower through a first reboiler, the top of the second rectifying tower is provided with a second condenser, the bottom of the second rectifying tower is in thermal coupling connection with the middle part of the third rectifying tower through a second reboiler, the top of the third rectifying tower is provided with a third condenser, and the bottom of the third rectifying tower is in thermal coupling connection with the middle part of the fourth rectifying tower through a third reboiler. According to the thermal coupling energy-saving tower of the NMP four-tower rectifying system, energy cascade utilization is realized through the four-tower thermal coupling design, the separation efficiency is improved by the ceramic filler, the heat transfer is optimized by the plate heat exchanger, the energy consumption is reduced by the waste heat recovery system, the whole structure is compact and stable, and the energy utilization efficiency in the NMP rectifying process is remarkably improved.

Inventors

  • LIANG BIN
  • TAN XUEJUN
  • ZHOU JUNBO

Assignees

  • 新迈奇材料股份有限公司

Dates

Publication Date
20260512
Application Date
20250528

Claims (6)

  1. 1. The heat coupling energy-saving tower of the NMP four-tower rectifying system comprises a first rectifying tower (1), a second rectifying tower (3), a third rectifying tower (5) and a fourth rectifying tower (7) which are sequentially connected in series, and is characterized in that a first condenser (2) is arranged at the top of the first rectifying tower (1), the bottom of the first rectifying tower is connected with the middle part of the second rectifying tower (3) through a first reboiler (9) in a heat coupling mode, a second condenser (4) is arranged at the top of the second rectifying tower (3), the bottom of the second rectifying tower is connected with the middle part of the third rectifying tower (5) through a second reboiler (10) in a heat coupling mode, a third condenser (6) is arranged at the top of the third rectifying tower (5), the bottom of the third rectifying tower is connected with the middle part of the fourth rectifying tower (7) through a third reboiler (11), a fourth condenser (8) is arranged at the top of the fourth rectifying tower (7), and a product outlet (13) is connected at the bottom of the fourth rectifying tower.
  2. 2. The thermally coupled energy-saving tower of the NMP four-tower rectifying system according to claim 1, wherein the first rectifying tower (1), the second rectifying tower (3), the third rectifying tower (5) and the fourth rectifying tower (7) are internally provided with high-efficiency structured packing (14).
  3. 3. The thermally coupled energy-saving tower of the NMP four-tower rectification system according to claim 1, wherein the outer sides of the first reboiler (9), the second reboiler (10) and the third reboiler (11) are respectively provided with a plate heat exchanger (17), and the plate heat exchanger (17) is composed of a plurality of heat exchange plates which are arranged in parallel.
  4. 4. The thermally coupled energy-saving tower of the NMP four-tower rectification system according to claim 1, wherein an energy economizer (12) is arranged at the bottom of the fourth rectification tower (7), and the energy economizer (12) is used for recovering waste heat in the rectification process.
  5. 5. The thermally coupled energy-saving tower of the NMP four-tower rectifying system according to claim 1, wherein the outer walls of the first rectifying tower (1), the second rectifying tower (3), the third rectifying tower (5) and the fourth rectifying tower (7) are respectively coated with an insulating layer (15), and the insulating layers (15) are made of high-temperature-resistant heat insulation materials.
  6. 6. The thermally coupled energy-saving tower of the NMP four-tower rectifying system according to claim 1, wherein the top of the first rectifying tower (1) is fixedly connected with a heat medium circulating system (16), and the first condenser (2), the second condenser (4), the third condenser (6) and the fourth condenser (8) are all communicated with the heat medium circulating system (16).

Description

Thermal coupling energy-saving tower of NMP four-tower rectifying system Technical Field The utility model relates to the technical field of four-tower rectification, in particular to a thermal coupling energy-saving tower of an NMP four-tower rectification system. Background N-methylpyrrolidone (NMP) is widely used in the fields of lithium batteries, electronic chemicals, medicines, paints and the like as an important polar aprotic solvent due to its excellent solubility and chemical stability. In the NMP production process, rectification and purification are key process links. At present, the NMP is mainly separated and purified by adopting a multi-tower continuous rectification process in industry, but the traditional rectification process has the technical problems of high energy consumption, low separation efficiency and the like because the NMP has the characteristics of high boiling point, poor thermal stability and the like. The existing NMP four-tower rectifying system has the problems that the heat energy utilization rate is low, the independent operation of each rectifying tower is mainly realized, the waste heat of a high-temperature tower cannot be effectively recycled, a condenser and a reboiler adopt a traditional shell-and-tube heat exchanger, the heat transfer efficiency is low, random packing or common tower plates are adopted for tower internals, the pressure drop is large, the mass transfer effect is not ideal, and aiming at the problems, the heat coupling energy-saving tower of the NMP four-tower rectifying system is provided. Disclosure of utility model The utility model discloses a thermal coupling energy-saving tower of an NMP four-tower rectifying system, which aims to solve the technical problems that waste heat of a high-temperature tower cannot be effectively recycled, a condenser and a reboiler adopt a traditional shell-and-tube heat exchanger, the heat transfer efficiency is low, tower internals adopt random packing or common tower plates, the pressure drop is large, and the mass transfer effect is not ideal. In order to achieve the above purpose, the present utility model adopts the following technical scheme: the utility model provides a thermal coupling economizer tower of four rectifying system of NMP, includes first rectifying column, second rectifying column, third rectifying column and fourth rectifying column that establish ties in proper order, the top of first rectifying column is equipped with first condenser, and its bottom is through the middle part thermal coupling connection of first reboiler and second rectifying column, the top of second rectifying column is equipped with the second condenser, and its bottom is through the middle part thermal coupling connection of second reboiler and third rectifying column, the top of third rectifying column is equipped with the third condenser, and its bottom is through the middle part thermal coupling connection of third reboiler and fourth rectifying column, the top of fourth rectifying column is equipped with the fourth condenser, and its bottom is connected with the product export. The energy cascade utilization is realized through the design of four-tower thermal coupling, the ceramic filler improves the separation efficiency, the plate heat exchanger optimizes heat transfer, the waste heat recovery system reduces energy consumption, the whole structure is compact and stable, and the energy utilization efficiency of the NMP rectification process is obviously improved. In a preferred scheme, the first rectifying tower, the second rectifying tower, the third rectifying tower and the fourth rectifying tower are internally provided with efficient structured packing, and the efficient structured packing is made of ceramic materials with specific geometric structures. The efficient structured packing made of the ceramic material has larger specific surface area and better corrosion resistance, can obviously improve the gas-liquid mass transfer efficiency, reduces the pressure drop in the tower, and is particularly suitable for the high-boiling-point rectification process of NMP. In a preferred scheme, the outer sides of the first reboiler, the second reboiler and the third reboiler are respectively provided with a plate heat exchanger, and the plate heat exchanger is composed of a plurality of heat exchange plates which are arranged in parallel. Through a plurality of heat exchange plate structures which are arranged in parallel, the heat exchange area is greatly increased, the heat transfer efficiency is improved, and the heat transfer between towers is more sufficient and uniform. In a preferred scheme, an economizer is arranged at the bottom of the fourth rectifying tower, and the economizer is used for recovering waste heat in the rectifying process. The energy economizer arranged at the bottom of the fourth rectifying tower can effectively recycle waste heat in the rectifying process, is used for preheating raw material