CN-224207407-U - Polyamide 6 extraction water evaporation concentration device

CN224207407UCN 224207407 UCN224207407 UCN 224207407UCN-224207407-U

Abstract

The utility model relates to the technical field of nylon production, in particular to a polyamide 6 extraction water evaporation concentration device, wherein the tube passes of a first-effect heat exchanger, a second-effect heat exchanger and a third-effect heat exchanger of the device are respectively provided with a circulation loop, extraction water to be concentrated enters from the tube pass of the first-effect heat exchanger, enters the tube pass of the second-effect heat exchanger after circulation heat exchange concentration, enters the third-effect heat exchanger after further circulation heat exchange concentration, enters a fourth-effect heat exchanger and a third separator after recirculation heat exchange, steam generated by the tube pass of the first-effect heat exchanger enters a first separator for separation, a gas phase enters the shell pass of the second-effect heat exchanger for separation, and the separated gas phase and the gas phase separated by the third separator are connected together to a spray washing tower and a compressor, and the compressed steam provides steam for the shell pass of the first-effect heat exchanger and the shell pass of the third-effect heat exchanger. The device has reasonable structure, can fully utilize heat energy and save energy.

Inventors

YIN YINHUA
JIN YANFENG
XIAO YAO
LIU WENTAO
LIN JUN
XIAO YAO

Assignees

湖北三宁化工股份有限公司

Dates

Publication Date: 20260508
Application Date: 20250429

Claims (7)

1. A polyamide 6 extraction water evaporation concentration device is characterized by comprising a first effect heat exchanger, a first separator, a second effect heat exchanger, a third effect heat exchanger, a second separator, a fourth effect heat exchanger and a third separator, wherein the tube passes of the first effect heat exchanger, the second effect heat exchanger and the third effect heat exchanger are respectively provided with a circulation loop, extraction water to be concentrated enters from the tube pass of the first effect heat exchanger, enters the tube pass of the second effect heat exchanger after circulation heat exchange concentration, enters the third effect heat exchanger after further circulation heat exchange concentration, enters the fourth effect heat exchanger and the third separator after recirculation heat exchange, steam generated by the tube pass of the first effect heat exchanger enters the first separator for separation, gas phase enters the shell pass of the second effect heat exchanger for separation, the separated gas phase and the gas phase separated by the third separator are connected to a spray washing tower and a compressor together, the compressed steam is provided for the shell pass of the first effect heat exchanger and the shell pass of the third effect heat exchanger, the steam is provided for the fourth effect heat exchanger, the steam is provided for the third effect heat exchanger, and the third effect heat exchanger is provided with a liquid phase separator, and a liquid phase separator is further provided with a liquid phase outlet connected to a concentrated storage tank.
2. The apparatus of claim 1, wherein the first-effect heat exchanger, the second-effect heat exchanger and the third-effect heat exchanger are falling film heat exchangers.
3. The apparatus of claim 1, wherein the steam condensate of the shell side of the first-effect heat exchanger, the second-effect heat exchanger and the third-effect heat exchanger is connected to a condensate storage tank, and a water outlet of the condensate storage tank is connected to the preheating heat exchanger for preheating the extraction water before entering the tube side of the first-effect heat exchanger.
4. The apparatus of claim 1, wherein the extract water to be concentrated enters from the top of the tube side of the primary heat exchanger, and the bottom outlet is connected to the secondary heat exchanger through a pipeline and enters from the lower part of the tube side.
5. The apparatus of any one of claims 1 to 4, wherein the compressors are provided in plural groups.
6. The apparatus according to claim 1 to 4, wherein the lower part of the spray scrubber is a spray pipe, the upper packing layer is arranged at the middle part of the spray scrubber, and the gas phase is led out into the compressor after passing through the packing layer.
7. The apparatus of claim 1, wherein a concentrate transfer tank and a filter are further disposed between the four-way heat exchanger and the concentrate storage tank.

Description

Polyamide 6 extraction water evaporation concentration device Technical Field The utility model belongs to the technical field of nylon production, and relates to a polyamide 6 extraction water evaporation concentration device. Background Polyamide 6, which is an aliphatic polyamide, is widely used in various fields such as fibers, engineering plastics, and films due to its light weight, high strength, and abrasion resistance, and stability in weak acids, weak bases, and certain organic solvents. In the process of preparing polyamide-6 from caprolactam as a monomer, the polycondensation reaction of caprolactam forms a variety of polymer molecules including highly condensed polymers, low condensed dimers and oligomers, and the like. These low molecular weight compounds, while in chemical equilibrium, generally represent 8% to 13% of the total mass. In order to improve the product quality, it is often necessary to extract these oligomers and unreacted epsilon caprolactam with water. CN208465213U discloses a polyamide 6 extraction water evaporation system, which realizes the accurate regulation of a three-effect evaporation tower by arranging a plurality of control valves in the evaporation system, and is traditional three-effect evaporation, and the steam consumption is relatively large. Disclosure of Invention The utility model provides a polyamide 6 extraction water evaporation concentration device, which is characterized in that forward feed is realized through the adjustment of a device structure, and secondary steam evaporated at last effect is compressed and reused after being recycled, so that energy can be saved. The technical scheme includes that the polyamide 6 extraction water evaporation concentration device comprises an effective heat exchanger, a first separator, a second effect heat exchanger, a third effect heat exchanger, a second separator, a fourth-order heat exchanger and a third separator, wherein circulating loops are respectively arranged on tube passes of the effective heat exchanger, the second effect heat exchanger and the third effect heat exchanger, extraction water to be concentrated enters from the tube passes of the effective heat exchanger, enters the tube passes of the second effect heat exchanger after circulating heat exchange concentration, enters the third effect heat exchanger after further circulating heat exchange concentration, enters the fourth-order heat exchanger and the third separator after recycling heat exchange, steam generated by the tube passes of the effective heat exchanger enters the first separator for separation, gas phase enters the shell pass of the second effect heat exchanger for separation, the separated gas phase and the gas phase generated by the tube passes of the third effect heat exchanger are connected to a spray washing tower and a compressor together, the compressed steam is provided with the shell pass of the effective heat exchanger and the shell of the third effect heat exchanger, the steam enters the fourth-order heat exchanger and the third-order heat exchanger is provided with a steam outlet of the third heat exchanger to be connected to an external liquid phase concentration storage tank. Further, the first-effect heat exchanger, the second-effect heat exchanger and the third-effect heat exchanger are all falling film heat exchangers. Further, steam condensate water of the shell passes of the first-effect heat exchanger, the second-effect heat exchanger and the third-effect heat exchanger is connected to a condensate storage tank, and a water outlet of the condensate storage tank is connected to a preheating heat exchanger and is used for preheating extraction water before entering the tube pass of the first-effect heat exchanger. Further, the extraction water to be concentrated enters from the top of the tube side of the primary heat exchanger, and the bottom discharge port is connected to the secondary heat exchanger through a pipeline and enters from the lower part of the tube side of the secondary heat exchanger. Further, the compressors are multiple groups. Further, the middle and lower parts of the spray washing tower are provided with spray pipelines, the upper part of the spray washing tower is provided with a packing layer, and gas phase is led out to enter the compressor after passing through the packing layer. Further, a concentrated solution transfer tank and a filter are arranged between the four-effect heat exchanger and the concentrated solution storage tank. The utility model has the following beneficial effects: The device provided by the utility model utilizes the steam generated by the final effect of multi-effect evaporation, and compresses the steam after removing impurities through washing, so that the temperature, pressure and enthalpy values of the secondary steam are greatly improved, the steam can reenter the one-effect heat exchanger for heating and evaporating extraction water, latent heat is released, the