CN-224212437-U - Ammonium sulfate crystallization wastewater recycling device

Abstract

The utility model relates to the technical field of caprolactam production, and particularly provides an ammonium sulfate crystallization wastewater recycling device which comprises a stripping tower, wherein a wastewater inlet is formed in the upper part of the stripping tower, a steam inlet is formed in the lower part of the stripping tower, a gas phase outlet is formed in the top of the stripping tower, the gas phase outlet is connected to a cooler through a pipeline and then connected to a reflux tank, the gas phase outlet of the reflux tank is connected to an ammonia gas washing tower, a desalted water inlet is formed in the upper part of the ammonia gas washing tower, a discharge hole in the lower part of the ammonia gas washing tower is connected with ammonium sulfate crystallization equipment through a pipeline and a discharge pump, the discharge pump is also connected to the desalted water inlet through a pipeline to form a circulation loop, and the liquid phase discharge hole of the reflux tank is connected to the feed back at the upper part of the stripping tower through the pipeline and the circulation pump. The device can treat the wastewater, recycle ammonia nitrogen in the wastewater, and directly recycle the wastewater to an ammonium sulfate neutralization crystallization process of caprolactam.

Inventors

• YIN YINHUA
• JIN YANFENG
• LUO WEIJING
• WU LINTAO
• JIN YANLI

Assignees

• 湖北三宁化工股份有限公司

Dates

Publication Date

20260508

Application Date

20250430

Claims (8)

1. 1. The ammonium sulfate crystallization wastewater recycling device is characterized by comprising a stripping tower, wherein a wastewater inlet is formed in the upper portion of the stripping tower, a steam inlet is formed in the lower portion of the stripping tower, a gas phase outlet is formed in the top of the stripping tower, the gas phase outlet is connected to a cooler through a pipeline and then connected to a reflux tank, the gas phase outlet of the reflux tank is connected to an ammonia gas washing tower, a desalted water inlet is formed in the upper portion of the ammonia gas washing tower, a discharge hole in the lower portion of the ammonia gas washing tower is connected with ammonium sulfate crystallization equipment through a pipeline and a discharge pump, the discharge pump is connected to the desalted water inlet through a pipeline to form a circulation loop, and a liquid phase discharge hole of the reflux tank is connected to a feed back hole in the upper portion of the stripping tower through the pipeline and the circulation pump.
2. 2. The apparatus of claim 1, further comprising a wastewater preheater, wherein the wastewater feed line is connected to the stripper wastewater feed port after passing through the wastewater preheater.
3. 3. The apparatus according to claim 2, wherein the stripping column is further provided with a discharge port at the bottom, which is connected to the waste water preheater via a bottom pump, exchanges heat with the waste water to be treated and outputs the waste water to be treated.
4. 4. The apparatus of claim 3, wherein a branch pipe is connected to the feed back port of the stripping tower between the bottom pump and the waste water preheater.
5. 5. The apparatus according to claim 1 to 4, wherein a ceramic packing layer or a structured packing layer is provided in the stripping tower.
6. 6. The apparatus of claim 5, wherein the wastewater feed port is connected to a liquid distributor, and the liquid distributor is positioned above the packing layer.
7. 7. The apparatus according to any one of claims 1 to 4, wherein the ammonia gas scrubber is provided with a gas distributor, a filler layer, a liquid sprayer and a demister from bottom to top.
8. 8. The apparatus of claim 1, wherein the cooler is a tube heat exchanger, and the heat exchange medium channel is connected with the circulating water pipeline or the waste water pipeline.

Description

Ammonium sulfate crystallization wastewater recycling device Technical Field The utility model belongs to the technical field of caprolactam production, and relates to an ammonium sulfate crystallization wastewater recycling device. Background Caprolactam is a monomer for synthesizing nylon (nylon-6) fibers, and is widely applied in the field of polymeric materials. At present, the domestic caprolactam production process mainly comprises cyclohexanone ammoximation-Beckmann rearrangement production, the production flow is long, the production process is complex, meanwhile, the byproducts are more, the yield of ammonium sulfate is very high, and the raw material economy is poor. In the process, the crystallization neutralization reaction is an important process, and a large amount of wastewater produced by the neutralization reaction cannot be directly utilized because the ammonia nitrogen content is about 1600 mg/L. At present, the high ammonia nitrogen wastewater is treated mainly by a physicochemical and biochemical combined method, wherein the physicochemical method mainly adopts a physicochemical method to treat the high-concentration ammonia nitrogen wastewater, and the toxic effect of the wastewater on microorganisms is not required to be considered. Mainly comprises a stripping method, a membrane separation technology, a break point chlorination method, a chemical precipitation method, a sulfuric acid absorption method, chemical oxidation and the like. Most of the methods have the problems of large equipment investment, high energy consumption and high operation cost, and restrict the further development of the physicochemical method. CN 117263416A discloses a caprolactam wastewater treatment device and a caprolactam wastewater treatment method, which are characterized in that wastewater is sent into a wet oxidation reactor for pretreatment so as to remove most of COD in the wastewater, then membrane filtration is carried out, the wastewater enters the wet oxidation reactor, COD and ammonia nitrogen in the wastewater are removed under the actions of high temperature, high pressure, oxygen and a catalyst, finally ammonia nitrogen is removed by electrodialysis, the cost is high, and ammonia nitrogen in the wastewater cannot be recycled. Disclosure of Invention The utility model provides an ammonium sulfate crystallization wastewater recycling device which can treat the wastewater and recycle ammonia nitrogen in the wastewater, and the wastewater can be directly recycled to an ammonium sulfate neutralization crystallization process of caprolactam. The technical scheme includes that the recycling device for the ammonium sulfate crystallization wastewater comprises a stripping tower, wherein a wastewater inlet is formed in the upper portion of the stripping tower, a steam inlet is formed in the lower portion of the stripping tower, a gas phase outlet is formed in the top of the stripping tower, the gas phase outlet is connected to a cooler through a pipeline and then connected to a reflux tank, the gas phase outlet of the reflux tank is connected to an ammonia gas washing tower, a desalted water inlet is formed in the upper portion of the ammonia gas washing tower, a discharge hole in the lower portion of the ammonia gas washing tower is connected with ammonium sulfate crystallization equipment through a pipeline and a discharge pump, the discharge pump is connected to the desalted water inlet through a pipeline to form a circulation loop, and a liquid phase discharge hole of the reflux storage tank is connected to a feed back hole in the upper portion of the stripping tower through the pipeline and the circulation pump. Further, the device also comprises a waste water preheater, and the waste water feeding pipe is connected to the waste water feeding hole of the stripping tower after passing through the waste water preheater. Further, a discharge hole is also arranged at the bottom of the stripping tower, and is connected to the waste water preheater through a tower bottom pump, and the waste water is discharged from the device after heat exchange with the waste water to be treated. Further, a branch pipe is also arranged between the tower bottom pump and the wastewater preheater and connected to a feed back port of the stripping tower. Further, a ceramic packing layer or a regular packing layer is arranged in the stripping tower. Further, the waste water feed inlet is connected with a liquid distributor, and the liquid distributor is positioned above the packing layer. Further, the ammonia gas washing tower is provided with a gas distributor, a packing layer, a liquid sprayer and a foam remover from bottom to top. Further, the cooler is a tube type heat exchanger, and a heat exchange medium channel of the cooler is connected with a circulating water pipeline or a waste water pipeline. The utility model has the following beneficial effects: The temperature of the wastewater containing ammonia nitrogen wit