Ammonium sulfate neutralization reaction heat utilization device

Abstract

The utility model relates to the field of chemical industry, and particularly provides an ammonium sulfate neutralization reaction heat utilization device which comprises a neutralization mixer, a discharge port of the neutralization mixer is connected to a gas-liquid separator, a steam pipeline is arranged at the upper part of the gas-liquid separator and is connected to heat utilization equipment, and a liquid phase discharge pipe is arranged at the lower part of the gas-liquid separator and is connected to a crystallizer; a condenser is connected to the top of the crystallizer and further connected with a vacuum unit, a pipeline and a decanter feeding pump are arranged on the lower portion of the middle of the crystallizer, and a pipeline and a slurry extraction pump are arranged at the bottom of the crystallizer. The device not only effectively utilizes ammonium sulfate neutralization reaction heat, but also can reduce the consumption of circulating water of the device so as to achieve the purposes of energy conservation and consumption reduction.

Description

TECHNICAL FIELD

[0001] The utility model belongs to fine chemical technology field relates to a kind of ammonium sulfate neutralization reaction heat utilization device. BACKGROUND

[0002] Caprolactam production in ammonium sulfate process needs to separate caprolactam in rearrangement liquid and oleum, and neutralization reaction occurs between gaseous ammonia and rearrangement liquid containing H2SO4 and a small amount of SO3 in neutralization reactor, to generate ammonium sulfate and produce crystal nucleus, then in crystallizer, it is divided into upper caprolactam solution and lower ammonium sulfate solution, and the caprolactam organic layer floating on the upper part of mother liquor is extracted together with a certain amount of mother liquor, and sent to decanter for further processing.

[0003] In the industrial production process of caprolactam, a large amount of water needs to be evaporated in the crystallizer to make ammonium sulfate solution supersaturated and precipitate crystals, and the reaction temperature of ammonium sulfate crystallizer in industrial caprolactam device is about 62℃, and the pressure is about-85kPa, and the water vapor temperature evaporated from the crystallizer is about 58℃, which needs to be cooled by a large amount of circulating water, resulting in a large amount of waste of neutralization reaction heat.

[0004] CN 103012273 A discloses a kind of neutralization crystallization system and method for preparing caprolactam from caprolactam rearrangement liquid, wherein the neutralization crystallization reactor is operated at-0.095MPaG, and the 50℃ water vapor evaporated by neutralization reaction heat cannot be utilized again, but can only be condensed by condenser, and the obtained condensate is returned to the neutralization crystallization reactor for recycling, resulting in waste of neutralization reaction heat. SUMMARY

[0005] The ammonium sulfate neutralization reaction heat utilization device provided by the utility model not only effectively utilizes the neutralization reaction heat of ammonium sulfate, but also reduces the amount of circulating water used by the device, achieving the purpose of energy saving and consumption reduction.

[0006] The technical scheme of the utility model provides an ammonium sulfate neutralization reaction heat utilization device, which comprises a neutralization mixer, the discharge port of which is connected to a gas-liquid separator, the upper part of the gas-liquid separator is provided with a steam pipeline connected to a heat-using equipment, the lower part is provided with a liquid-phase discharge pipe connected to a crystallizer; the top of the crystallizer is connected to a condenser, the condenser is further connected to a vacuum unit, the middle lower part of the crystallizer is provided with a pipeline and a decanter inlet pump, and the bottom of the crystallizer is provided with a pipeline and a slurry extraction pump.

[0007] Optionally, the neutralization mixer is a Venturi type, wherein the ammonium sulfate mother liquor passes through the throat pipe, and the rearrangement ester passes through the openings around the throat pipe.

[0008] Optionally, the top of the gas-liquid separator is provided with a second pressure remote transmission, and a second pressure regulating valve is arranged on the steam pipeline; the second pressure remote transmission, the second pressure transmitter and the second pressure regulating valve form a control loop to adjust the pressure in the gas-liquid separator.

[0009] Optionally, the lower part of the gas-liquid separator is provided with a liquid level meter and a liquid level remote transmission.

[0010] Optionally, a first pressure regulating valve is further arranged on the pipeline between the gas-liquid separator and the crystallizer, a first pressure remote transmission is arranged on the crystallizer, and the first pressure remote transmission, the first pressure transmitter and the first pressure regulating valve form a control loop to adjust the pressure in the crystallizer.

[0011] Optionally, the bottom of the crystallizer is further provided with a stirring paddle.

[0012] Optionally, the lower part of the crystallizer is further provided with a draft tube.

[0013] Optionally, a baffle is arranged above the pipeline connecting the decanter feed pump in the middle of the crystallizer.

[0014] The utility model has the following beneficial effects:

[0015] In the device, ammonia gas, circulating ammonium sulfate mother liquor and transposition ester are reacted through a neutralizing mixer and release heat at the same time, enter a gas-liquid separator, the gas-liquid separator is provided with a liquid level meter and a liquid level remote transmission, the lower part liquid level is guaranteed, and pressure is avoided from being connected; the pressure control part of the top of the gas-liquid separator can control the pressure in the gas-liquid separator to be 0.1~0.5MPa, and the reaction heat gasifies most of the water in the ammonium sulfate aqueous solution into 100~150 DEG C high-temperature steam, which can be used for other heat-using equipment. The mixed solution of caprolactam and ammonium sulfate at the bottom of the gas-liquid separator enters a crystallizer through pressure difference, the pressure in the crystallizer is adjusted to be negative (-85kPa), and the temperature is about 60~70 DEG C, the bottom is provided with a stirring paddle, the top is connected with a condenser and a vacuum unit, the supersaturated ammonium sulfate solution flows downward, the ammonium sulfate crystal is well grown, the light phase in the upper part is a caprolactam organic layer, the part of the organic layer is extracted together with a certain amount of mother liquor, is sent to a decanter through a decanter feed pump for further treatment, and the ammonium sulfate crystal slurry extracted from the bottom of the crystallizer is sent to a centrifugal drying process through a slurry extraction pump.

[0016] The utility model can fully recycle the heat of ammonium sulfate neutralization reaction, convert low-grade reaction heat into low-pressure steam, is convenient to use, can greatly reduce the amount of circulating water, achieves the purpose of energy saving and consumption reduction, the whole device has reasonable process flow design, simple operation, low investment cost and remarkable economic benefits. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1The utility model discloses a structure schematic drawing. In the drawing, 1. neutralization mixer, 2. gas-liquid separator, 3. crystallizer, 4. slurry extraction pump, 5. stirring paddle, 6. decanter feed pump, 7. condenser, 8. vacuum unit, 9. first pressure remote, 10. first pressure transmitter, 11. first pressure regulating valve, 12. liquid level meter, 13. liquid level remote, 14. second pressure remote, 15. second pressure transmitter, 16. second pressure regulating valve. DETAILED DESCRIPTION

[0018] The embodiments of the utility model will be described in detail below in combination with examples and drawings, but the person skilled in the art will understand that the following examples are only for illustrating the utility model and should not be regarded as limiting the scope of the utility model.

[0019] As Figure 1 Indicated, the utility model provides a kind of ammonium sulfate neutralization reaction heat utilization device, including neutralization mixer 1, its discharge port is connected to gas-liquid separator 2, wherein gas-liquid separator 2 upper portion is equipped with steam pipeline, is connected to heat-using equipment, lower portion is equipped with liquid phase discharge pipe, is connected to crystallizer 3;Crystallizer top is connected with condenser 7, condenser is also connected with vacuum unit 8, and the middle lower portion of crystallizer is equipped with pipeline and decanter feed pump 6, and crystallizer bottom is equipped with pipeline and slurry extraction pump 4.

[0020] In some embodiments, the neutralization mixer is a venturi, wherein the ammonium sulfate mother liquor passes through the throat, and the ester passes through the holes around the throat. This can fully mix the materials and promote the reaction.

[0021] In some embodiments, the gas-liquid separator 2 is provided with a second pressure remote 14 at the top, and a second pressure regulating valve 16 is provided on the steam pipeline. The second pressure remote 14, the second pressure transmitter 15, and the second pressure regulating valve 16 form a control loop to adjust the pressure in the gas-liquid separator. In a preferred embodiment, the pressure in the gas-liquid separator is controlled to be 0.1-0.5 MPa. The reaction heat vaporizes most of the water in the ammonium sulfate aqueous solution into high-temperature steam at 100-150°C, which is discharged from the steam pipeline at the top of the gas-liquid separator to provide heat for other heat-using equipment.

[0022] In some embodiments, the gas-liquid separator 2 is provided with a liquid level meter 12 and a liquid level remote 13 at the lower portion to display the liquid level and ensure that the lower portion of the gas-liquid separator is not under pressure.

[0023] In some embodiments, a first pressure regulating valve 11 is further arranged on the pipeline between the gas-liquid separator 2 and the crystallizer, and a first pressure remote transmission 9 is arranged on the crystallizer, the first pressure remote transmission 9, the first pressure transmitter 10 and the first pressure regulating valve 11 form a control loop to adjust the pressure in the crystallizer. Especially when the vacuum degree in the crystallizer 3 rapidly decreases, the pressure can be avoided by closing the first pressure regulating valve.

[0024] In some embodiments, the bottom of the crystallizer is further provided with a stirring paddle 5 to stir the material in the bottom and promote the flow of the material.

[0025] In some embodiments, the lower part of the crystallizer is further provided with a draft tube, and in the lower area outside the draft tube, the flow rate is reduced due to the change of the shape of the crystallizer, a part of the suspension returns through the action of the stirrer, and another part flows upward to the baffle area, where ammonium sulfate is separated from the mother liquor, and the caprolactam organic layer floating on the upper part of the mother liquor is pumped to the decanter through the decanter feed pump for further treatment, and the ammonium sulfate crystal slurry extracted from the bottom of the crystallizer is pumped to the centrifugal drying process by the slurry extraction pump.

[0026] The above devices are connected through pipelines, and control valves are arranged on the pipelines.

[0027] The above embodiments describe the preferred embodiments of the present application, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solution of the present application, including the combination of various technical features in any other way. These simple modifications and combinations should also be considered as the disclosed content of the present application, and all belong to the protection scope of the present application. Therefore, the protection scope of the present application patent should be subject to the appended claims.

Claims

1. A device for utilizing the heat of ammonium sulfate neutralization reaction, characterized in that: It comprises a neutralization mixer (1), the outlet of which is connected to a gas-liquid separator (2), the upper part of which is provided with a steam pipeline connected to a heat-using device, and the lower part of which is provided with a liquid-phase outlet pipeline connected to a crystallizer (3); the top of the crystallizer is connected to a condenser (7), which is further connected to a vacuum unit (8), and the middle lower part of the crystallizer is provided with a pipeline and a decanter feed pump (6), and the bottom of the crystallizer is provided with a pipeline and a slurry extraction pump (4).

2. The apparatus of claim 1, wherein: The neutralization mixer is a Venturi type, in which the ammonium sulfate mother liquor passes through the throat pipe, and the transposition ester passes through the holes around the throat pipe.

3. The apparatus of claim 1, wherein: The top of the gas-liquid separator (2) is provided with a second pressure remote transmission (14), and the steam pipeline is provided with a second pressure regulating valve (16); the second pressure remote transmission (14), the second pressure transmitter (15) and the second pressure regulating valve (16) form a control loop to adjust the pressure in the gas-liquid separator.

4. The apparatus of claim 1, wherein: The lower part of the gas-liquid separator (2) is provided with a liquid level meter (12) and a liquid level remote transmission (13).

5. The apparatus of claim 1, wherein: The pipeline between the gas-liquid separator (2) and the crystallizer is further provided with a first pressure regulating valve (11), and the crystallizer is provided with a first pressure remote transmission (9); the first pressure remote transmission (9), the first pressure transmitter (10) and the first pressure regulating valve (11) form a control loop to adjust the pressure in the crystallizer.

6. The apparatus of any one of claims 1-5, wherein: The bottom of the crystallizer is further provided with a stirring paddle (5).

7. The apparatus of any one of claims 1-5, wherein: The lower part of the crystallizer is further provided with a draft tube.

8. The apparatus of any one of claims 1-5, wherein: The upper part of the pipeline connecting the decanter feed pump in the middle of the crystallizer is provided with a baffle.

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