Carbon dioxide supply equipment for cyanamide hydrolysis

Abstract

The utility model relates to carbon dioxide supply equipment for cyanamide hydrolysis, which comprises a liquid carbon dioxide storage tank, a first constant-pressure pump, a gasification tank and a second constant-pressure pump, and a carbon dioxide outlet of the liquid carbon dioxide storage tank is communicated with an input end of the first constant-pressure pump through a first pipeline. The output end of the first constant pressure pump is communicated with the carbon dioxide inlet of the gasification tank through a second pipeline, the carbon dioxide outlet of the gasification tank is communicated with the input end of the second constant pressure pump through a third pipeline, and the output end of the second constant pressure pump is connected with a fourth pipeline used for conveying carbon dioxide into the cyanamide hydrolysis kettle; a pressure increasing valve, a first pressure sensor and a pressure release valve are sequentially installed on the fourth pipeline in the carbon dioxide output direction. According to the utility model, the stability and efficiency of carbon dioxide supply are improved, energy in the supply process is effectively utilized, and the utilization rate of energy resources is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of monomethylamine production, especially carbon dioxide supply technology, specifically refers to a kind of carbon dioxide supply equipment for monomethylamine hydrolysis. BACKGROUND

[0002] The scientific name of monomethylamine is cyanamide, which is also known as cyanamide. It is used in pesticides, pharmaceutical intermediates and cyanuric amide. Monomethylamine solution is used as a defoliant for fruit trees and a non-toxic insecticide abroad. The existing monomethylamine is usually produced by low-temperature hydrolysis. Lime nitrogen and water are added to the hydrolysis kettle for hydrolysis reaction, and carbon dioxide is introduced for calcification reaction, so that monomethylamine solution is obtained. The hydrolysis reactor for monomethylamine production disclosed in patent CN213286815U is a commonly used hydrolysis kettle. Carbon dioxide is introduced through the gas inlet pipe during production, and cooling water system is used for cooling.

[0003] The existing carbon dioxide supply method usually gasifies liquid carbon dioxide and then supplies it to the hydrolysis kettle for reaction. The stability of the supply needs to be ensured during the process. When liquid carbon dioxide is gasified, a large amount of heat is absorbed, and the existing equipment does not utilize the energy during the phase change process, resulting in waste of energy resources. UTILITY MODEL CONTENT

[0004] The utility model provides a kind of carbon dioxide supply equipment for monomethylamine hydrolysis to solve the problems of prior art, improve the stability, efficiency of carbon dioxide supply, effectively utilize energy during supply process, and improve energy resource utilization rate.

[0005] The utility model is realized by the following technical scheme, a kind of carbon dioxide supply equipment for monomethylamine hydrolysis, including liquid carbon dioxide storage tank, first constant pressure pump, gasification tank and second constant pressure pump, the carbon dioxide outlet of the liquid carbon dioxide storage tank is communicated with the input end of the first constant pressure pump by first pipeline, the output end of the first constant pressure pump is communicated with the carbon dioxide inlet of the gasification tank by second pipeline, the carbon dioxide outlet of the gasification tank is communicated with the input end of the second constant pressure pump by third pipeline, the output end of the second constant pressure pump is connected with the fourth pipeline for delivering carbon dioxide to monomethylamine hydrolysis kettle, the fourth pipeline is installed with pressure increasing valve, first pressure sensor and pressure relief valve in turn along carbon dioxide output direction.

[0006] The liquid carbon dioxide stored in the liquid carbon dioxide storage tank is pumped by the first constant pressure pump to be delivered to the gasification tank to be gasified into carbon dioxide gas at a constant pressure. The liquid carbon dioxide is discharged from the liquid carbon dioxide storage tank stably by the constant pressure supply of the first constant pressure pump, and the stability is higher. The carbon dioxide gas is pumped by the second constant pressure pump and discharged from the gasification tank stably and enters the fourth pipeline to further ensure the stability. The carbon dioxide gas in the fourth pipeline is pressurized by the pressure increasing valve to increase the gas pressure, so that the carbon dioxide gas can be quickly sprayed into the cyanamide hydrolysis kettle to fully contact with the reaction solution and participate in the reaction, thereby improving the reaction efficiency. The supply pressure of the carbon dioxide gas is monitored by the first pressure sensor.

[0007] The carbon dioxide gas is depressurized by the pressure relief valve to prevent overpressure and improve safety.

[0008] As an optimization, a second pressure sensor is installed on the first pipeline. The second pressure sensor monitors the supply pressure of the liquid carbon dioxide.

[0009] As an optimization, a gas check valve is installed on the second pipeline. The gas check valve prevents backflow of the carbon dioxide gas to affect the stability of the supply.

[0010] As an optimization, an electromagnetic flowmeter is installed on the third pipeline. The electromagnetic flowmeter facilitates calculation and control of the supply amount of the carbon dioxide gas.

[0011] As an optimization, the gasification tank includes an outer tank body and an inner tank body fixed inside the outer tank body, and an annular heat exchange cavity is formed between the outer tank body and the inner tank body. The inner tank body is provided with a carbon dioxide inlet and a carbon dioxide outlet, and the outer tank body is provided with a cooling medium inlet and a cooling medium outlet, which are in communication with the cooling coil of the cyanamide hydrolysis kettle. In this optimization, the inner cavity of the inner tank body serves as a carbon dioxide gasification cavity, and the liquid carbon dioxide supplied by the second pipeline is gasified in the inner tank body. After the cooling medium and the reaction solution in the cooling coil of the cyanamide hydrolysis kettle are heated and warmed, the cooling medium enters the heat exchange cavity of the gasification tank through the cooling medium inlet, and the liquid carbon dioxide absorbs the heat of the cooling medium to accelerate gasification, and at the same time exchanges heat with the cooling medium to cool the cooling medium, and then reenters the cooling coil of the cyanamide hydrolysis kettle through the cooling medium outlet to form a circulating cooling, effectively utilizing the energy generated by the phase change to improve the energy resource utilization rate.

[0012] The utility model discloses beneficial effect is: store in the liquid carbon dioxide storage tank in liquid carbon dioxide through the pumping of first constant pressure pump, with constant pressure delivery to the gasification tank in the carbon dioxide gas gasification, through the constant pressure supply of first constant pressure pump, make liquid carbon dioxide stable from liquid carbon dioxide storage tank discharge, and the stability is higher. Carbon dioxide gas is pumped through second constant pressure pump, and stable from the gasification tank discharge and enter the fourth pipeline, further guarantee stability. The fourth pipeline carbon dioxide gas is through pressure -increasing valve pressure -increasing gas pressure, thereby make carbon dioxide gas can be quickly spouted into cyanamide hydrolysis kettle, and contact with reaction solution and participate in the reaction fully, improve the reaction efficiency. Through first pressure sensor monitoring carbon dioxide gas's supply pressure. Through pressure relief valve to carbon dioxide gas pressure relief, prevent overpressure, improve security;

[0013] After cooling medium and reaction solution heat exchange and temperature rise in the cooling coil of cyanamide hydrolysis kettle, enter the heat exchange cavity of gasification tank through cooling medium import, and liquid carbon dioxide gasification absorbs heat, thereby absorbs the heat of cooling medium and quickens gasification, and exchanges heat with cooling medium, makes cooling medium temperature drop, and reenters the cooling coil of cyanamide hydrolysis kettle through cooling medium export and forms circulation cooling, effectively utilizes the energy produced by phase change, improves energy resource utilization rate. BRIEF DESCRIPTION OF DRAWINGS

[0014] Fig. 1 It is flow chart schematic diagram of the utility model;

[0015] Fig. 2 It is gasification tank sectional view;

[0016] The shown in the figure:

[0017] 1, liquid carbon dioxide storage tank, 2, first pipeline, 3, second pressure sensor, 4, first constant pressure pump, 5, second pipeline, 6, gas check valve, 7, gasification tank, 71, outer tank body, 72, inner tank body, 73, heat exchange cavity, 74, gasification cavity, 8, third pipeline, 9, electromagnetic flowmeter, 10, second constant pressure pump, 11, fourth pipeline, 12, pressure booster, 13, first pressure sensor, 14, pressure relief valve, 15, cyanamide hydrolysis kettle, 16, cooling medium import, 17, cooling medium export, 18, water pump. DETAILED DESCRIPTION

[0018] To be able to clearly illustrate the technical features of the scheme, below through specific implementation, the scheme is described.

[0019] The patent CN213286815U discloses a hydrolysis reactor for monocyamine production. During production, water is added to the monocyamine hydrolysis reactor through a water inlet pipe, lime nitrogen is added to the monocyamine hydrolysis reactor through a feeding mechanism, and carbon dioxide is introduced to participate in the reaction through an air inlet pipe, thereby obtaining a monocyamine liquid. During the reaction process, the reaction solution is cooled by a cooling water system. The cooling water system is connected to a cooling pool and a hot water pool at both ends of the cooling coil to realize circulating cooling.

[0020] The patent does not disclose the supply mode of carbon dioxide. In traditional monocyamine production, the supply mode of carbon dioxide is usually to gasify liquid carbon dioxide and then supply it to the hydrolysis reactor for reaction. The stability of the supply needs to be ensured during the process. When liquid carbon dioxide is gasified, a large amount of heat is absorbed. The patent does not utilize the energy generated during this phase change process, resulting in a waste of energy resources. Therefore, the present scheme provides a carbon dioxide supply equipment for monocyamine hydrolysis.

[0021] As shown in the accompanying drawings, Figs. 1-2 a carbon dioxide supply equipment for monocyamine hydrolysis includes a liquid carbon dioxide storage tank 1, a first constant pressure pump 4, a gasification tank 7, and a second constant pressure pump 10.

[0022] The carbon dioxide outlet of the liquid carbon dioxide storage tank 1 is communicated with the input end of the first constant pressure pump 4 through a first pipeline 2, and a second pressure sensor 3 is installed on the first pipeline 2. The output end of the first constant pressure pump 4 is communicated with the carbon dioxide inlet of the gasification tank 7 through a second pipeline 5, and a gas check valve 6 is installed on the second pipeline 5.

[0023] In use, the liquid carbon dioxide stored in the liquid carbon dioxide storage tank 1 is pumped by the first constant pressure pump 4 to be supplied to the gasification tank 7 at a constant pressure, so that the liquid carbon dioxide is stably discharged from the liquid carbon dioxide storage tank 1, and the stability is higher. The liquid carbon dioxide enters the gasification tank 7 and is gasified into carbon dioxide gas at normal temperature and pressure. The second pressure sensor 3 monitors the liquid carbon dioxide delivery pressure in real time during the supply process, and the gas check valve 6 prevents the backflow of carbon dioxide gas, which affects the stability of the supply.

[0024] Specifically, the gasification tank 7 includes an outer tank body 71 and an inner tank body 72 fixedly arranged in the inner tank body 71, and an annular heat exchange cavity 73 is formed between the outer tank body 71 and the inner tank body 72. The inner cavity of the inner tank body 72 is a gasification cavity 74.

[0025] The inner tank body 72 is provided with a carbon dioxide inlet and a carbon dioxide outlet, and the second pipeline 5 is connected with the carbon dioxide inlet on the inner tank body 72 after penetrating through the outer tank body 71, thereby realizing the delivery of liquid carbon dioxide to the gasification cavity 74 for gasification.

[0026] The outer tank body 71 is provided with a cooling medium inlet 16 and a cooling medium outlet 17, which are in communication with the cooling coil of the monocyanoamine hydrolysis kettle 15. The monocyanoamine hydrolysis kettle 15 of the present embodiment adopts the kettle body described in patent CN213286815U, and the kettle cover is vertically provided with a water feeding pipe, a gas feeding pipe and a stirring mechanism. The kettle body is provided with a feeding mechanism, and the side wall of the kettle body is provided with a cooling layer, and the cooling layer is provided with the cooling coil. The cooling medium inlet 16 and the cooling medium outlet 17 on the outer tank body 71 are respectively in communication with the two ends of the cooling coil, so that the heat exchange cavity 73 and the cooling coil form a circulating passage. In order to facilitate the transportation of the cooling medium, water pumps 18 can be installed at both ends of the cooling coil for pumping the cooling medium.

[0027] In use, the cooling medium in the cooling coil and the reaction solution are heated by heat exchange, and then enter the heat exchange cavity 73 of the gasification tank 7 through the cooling medium inlet 16. The liquid carbon dioxide gasifies and absorbs the heat of the cooling medium, thereby accelerating the gasification efficiency. At the same time, the cooling medium is cooled by heat exchange, and then reenters the cooling coil through the cooling medium outlet 17 to cool the reaction solution by heat exchange, thereby forming a circulating cooling, effectively utilizing the energy generated by the phase change, and improving the energy resource utilization rate.

[0028] The carbon dioxide outlet of the gasification tank 7 is in communication with the input end of the second constant pressure pump 10 through the third pipeline 8, and the electromagnetic flowmeter 9 is installed on the third pipeline 8. The output end of the second constant pressure pump 10 is connected with the fourth pipeline 11 for delivering carbon dioxide into the monocyanoamine hydrolysis kettle 15, and the fourth pipeline 11 is sequentially provided with a pressure increasing valve 12, a first pressure sensor 13 and a pressure relief valve 14 along the direction of carbon dioxide output.

[0029] Specifically, the third pipeline 8 is connected with the carbon dioxide outlet on the inner tank body 72 after penetrating through the outer tank body 71, so that the carbon dioxide gas enters the third pipeline for being pumped by the second constant pressure pump 10. The fourth pipeline 11 is connected with the gas feeding pipe of the monocyanoamine hydrolysis kettle 15, so that the pumped carbon dioxide gas is supplied into the monocyanoamine hydrolysis kettle 15 to participate in the reaction.

[0030] In use, the carbon dioxide gas is pumped by the second constant pressure pump 10, stably discharged from the gasification tank 7 and enters the fourth pipeline 11, further ensuring the stability. The carbon dioxide gas in the fourth pipeline 11 is pressurized to 2MPa by the pressure increasing valve 12, so as to increase the gas pressure, thereby enabling the carbon dioxide gas to be quickly injected into the monocyanoamine hydrolysis kettle 15 to fully contact with the reaction solution and participate in the reaction, thereby improving the reaction efficiency. The supply pressure of the carbon dioxide gas is monitored by the first pressure sensor 13. The pressure relief pressure of the pressure relief valve 14 is 2.5MPa, and when the pressure exceeds 2.5MPa, the pressure relief valve is opened to relieve the pressure of the carbon dioxide gas, thereby preventing the pressure from being too high and improving the safety.

[0031] Of course, the above description is not limited to the above examples, and the technical features not described in the utility model can be realized by or using the prior art, which will not be described here; the above embodiments and drawings are only used to illustrate the technical solutions of the utility model and are not a limitation on the utility model, and the preferred embodiments of the utility model have been described in detail, and those skilled in the art should understand that the changes, modifications, additions or replacements made by those skilled in the art within the essential scope of the utility model do not deviate from the purpose of the utility model, and should also belong to the protection scope of the claims of the utility model.

Claims

1. A carbon dioxide supply apparatus for hydrolysis of monomethylamine, characterized by: The device comprises a liquid carbon dioxide storage tank (1), a first constant pressure pump (4), a gasification tank (7) and a second constant pressure pump (10), the carbon dioxide outlet of the liquid carbon dioxide storage tank (1) is communicated with the input end of the first constant pressure pump (4) through a first pipeline (2), the output end of the first constant pressure pump (4) is communicated with the carbon dioxide inlet of the gasification tank (7) through a second pipeline (5), the carbon dioxide outlet of the gasification tank (7) is communicated with the input end of the second constant pressure pump (10) through a third pipeline (8), the output end of the second constant pressure pump (10) is connected with a fourth pipeline (11) for delivering carbon dioxide into a cyanamide hydrolysis kettle (15), and the fourth pipeline (11) is sequentially provided with a pressure boosting valve (12), a first pressure sensor (13) and a pressure relief valve (14) in the direction of carbon dioxide output.

2. The carbon dioxide supply apparatus for hydrolysis of monosodium cyanamide according to claim 1, characterized by: A second pressure sensor (3) is installed on the first pipeline (2).

3. The carbon dioxide supply apparatus for hydrolysis of monosodium cyanamide according to claim 1, characterized by: A gas check valve (6) is installed on the second pipeline (5).

4. The carbon dioxide supply apparatus for hydrolysis of monosodium cyanamide according to claim 1, characterized by: An electromagnetic flowmeter (9) is installed on the third pipeline (8).

5. The carbon dioxide supply apparatus for hydrolysis of monosodium cyanamide according to any one of claims 1 to 4, characterized by: The gasification tank (7) comprises an outer tank body (71) and an inner tank body (72) fixed in the inner part of the outer tank body, an annular heat exchange cavity (73) is formed between the outer tank body and the inner tank body, the inner tank body (72) is provided with a carbon dioxide inlet and a carbon dioxide outlet, the outer tank body (71) is provided with a cooling medium inlet (16) and a cooling medium outlet (17), and the cooling medium inlet and the cooling medium outlet are communicated with the cooling coil of the cyanamide hydrolysis kettle (15).

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