Desulfurization and decarbonization device for coal gas countercurrent flow heat exchange

Abstract

The utility model discloses a coal gas countercurrent flow heat exchange desulfurization and decarbonization device, which relates to the technical field of desulfurization and decarbonization, and comprises a heat exchanger, a grating and a condenser pipe, the heat exchanger consists of an end socket, a barrel and a barrel cover, the barrel is provided with a coal gas outlet, a nitrogen outlet and a liquid nitrogen inlet, the barrel cover is provided with a coal gas inlet, and the end socket is provided with a coal gas outlet. Liquid nitrogen enters the condensation pipe from the liquid nitrogen inlet, pollutants in the coal gas are cooled to a condensation point through countercurrent flow heat exchange with the coal gas, the removal efficiency is high, the environment-friendly requirement is better met, the structure is simple, operation is convenient, the liquid nitrogen can be conveyed out of an air separation device of an oxygen station attached to an iron and steel plant, vaporized nitrogen can be continuously supplied to other users of the iron and steel plant, and the energy-saving and environment-friendly effects are achieved. The coal gas heat and the liquid nitrogen cold can be recovered simultaneously, and the energy-saving requirement is met.

Description

Technical Field

[0001] The utility model relates to the technical field of desulfurization and decarbonization, in particular to a desulfurization and decarbonization device for coal gas countercurrent heat exchange. Background Art

[0002] The statements herein merely provide background art related to the present invention and do not necessarily constitute prior art.

[0003] The steel industry is a pillar industry in my country. As the country's requirements for energy and environmental protection industries increase, the existing coal gas needs to be desulfurized, dechlorinated, and dehydrated to meet environmental protection requirements. At the same time, in order to improve user production efficiency, the calorific value of coal gas needs to be increased and the carbon dioxide in the coal gas needs to be removed.

[0004] The carbon dioxide content in the existing blast furnace gas is about 14.5%, and removing it can greatly increase the calorific value of the gas. Sulfides such as hydrogen sulfide, carbonyl sulfide, and carbon disulfide are pollutants that are difficult to remove. The existing desulfurization equipment is generally large and the process is complicated. Among them, hydrogen chloride will corrode subsequent pipelines and equipment after dissolving in water, and it also needs to be removed. In the existing blast furnace gas purification process, the above impurities need to be removed separately, using a lot of equipment, occupying a large area, and the removal efficiency is not high. Utility Model Content

[0005] In view of the shortcomings of the prior art, the purpose of the utility model is to provide a coal gas countercurrent heat exchange desulfurization and decarbonization device, which condenses hydrogen sulfide and carbon dioxide in the coal gas through liquid nitrogen, and removes impurities such as water and hydrogen chloride at the same time, thereby solving the problem of blast furnace gas desulfurization and decarbonization.

[0006] In order to achieve the above-mentioned purpose, the present invention is implemented through the following technical solutions:

[0007] The utility model provides a desulfurization and decarbonization device for coal gas countercurrent heat exchange, comprising: a heat exchanger, wherein the heat exchanger comprises a cylinder cover, a cylinder and a sealing head; the cylinder cover is arranged on the top of the cylinder, and the sealing head is arranged on the lower part of the cylinder; the sealing head is provided with a carbon dioxide outlet, the cylinder cover is provided with a coal gas inlet, and the outer surface of the cylinder is provided with a coal gas outlet, a nitrogen outlet, and a liquid nitrogen inlet; a grid and a condenser are arranged in the cylinder; the cylinder cover, the cylinder and the sealing head are connected by welding.

[0008] Furthermore, the cylinder cover is a hemispherical dome, and the gas inlet is arranged at the top center of the sphere; the head is an inverted cone, and the carbon dioxide outlet is arranged at the top of the cone; and the cylinder is a hollow cylindrical tubular structure.

[0009] Furthermore, the gas outlet and the liquid nitrogen inlet are relatively arranged on a side close to the sealing head.

[0010] Furthermore, the liquid nitrogen inlet is higher than the coal gas outlet in the horizontal direction.

[0011] Furthermore, the nitrogen outlet is arranged on a side close to the cylinder cover and in the same direction as the horizontal direction of the gas outlet.

[0012] Furthermore, the grid is arranged below the connection position between the cylinder cover and the cylinder and above the nitrogen outlet.

[0013] Furthermore, the grilles are evenly arranged in a tic-tac-toe pattern within the cylinder.

[0014] Furthermore, the condenser is arranged in a serpentine shape below the grille in the cylinder.

[0015] Furthermore, one end of the condenser is connected to a liquid nitrogen inlet, and the other end is connected to a nitrogen outlet.

[0016] Furthermore, the serpentine turning point of the condenser tube is a right-angle connection structure with an arc.

[0017] The beneficial effects of the embodiments of the present utility model are as follows:

[0018] 1. In the coal gas cooling desulfurization and decarbonization device of the utility model, the coal gas enters the heat exchanger through the coal gas inlet arranged on the cylinder cover, and is evenly distributed in the heat exchanger cylinder through the grille. By exchanging heat with the liquid nitrogen in the condenser, the pollutants with high boiling points that are difficult to remove during the coal gas treatment process are condensed into a liquid state, and the pollutants with low boiling points that are easy to treat (low boiling point pollutants and combustibles) are kept in a gaseous state. The generated liquid pollutants are treated separately, and the gaseous pollutants (pollutants and combustibles) are directly discharged and used as fuel gas. Compared with other decontamination devices, the device has a simple structure, is easy to operate, and reduces the difficulty of operation. It can remove impurities in one set of equipment, reduces the number of equipment used, and is more economical.

[0019] 2. The coal gas cooling desulfurization and carbon removal device of the utility model has high removal efficiency by cooling down to the condensation point, and better meets environmental protection requirements.

[0020] 3. In the utility model of coal gas cooling desulfurization and decarbonization device, liquid nitrogen can be transported out from the air separation device of the oxygen station attached to the steel plant, and the vaporized nitrogen can continue to be supplied to other users of the steel plant, so that the heat of coal gas and the cooling capacity of liquid nitrogen can be recovered at the same time, meeting the energy-saving requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention.

[0022] Figure 1 It is a structural schematic diagram of the coal gas cooling, desulfurization and decarbonization device of the utility model.

[0023] Figure 2 It is a structural schematic diagram of the grille of the utility model.

[0024] Figure 3 This is an enlarged view A of the turning position structure of the condenser tube of the utility model;

[0025] In the figure: 1. Cylinder; 2. Gas inlet; 3. Gas outlet; 4. Nitrogen outlet; 5. Liquid nitrogen inlet; 6. Carbon dioxide outlet; 7. Grille; 8. Condenser; 9. Cylinder cover; 10. End cap.

[0026] In order to show the positions of various parts, the distances or sizes between them are exaggerated and the schematic diagram is for reference only. DETAILED DESCRIPTION

[0027] As described in the background technology, the existing desulfurization equipment is generally large and the process is complicated. When hydrogen chloride dissolves in water, it will corrode subsequent pipelines and equipment and also needs to be removed. In the existing blast furnace gas purification process, the above impurities need to be removed separately, using many equipment, occupying a large area, and the removal efficiency is not high.

[0028] In order to solve the above technical problems, the utility model provides a coal gas countercurrent heat exchange desulfurization and decarbonization device, which condenses hydrogen sulfide and carbon dioxide in the coal gas through liquid nitrogen, and removes impurities such as water and hydrogen chloride at the same time, thereby solving the problem of large footprint and low efficiency of blast furnace gas desulfurization and decarbonization equipment.

[0029] like Figure 1-Figure 3 As shown, the utility model embodiment records a coal gas countercurrent heat exchange desulfurization and decarbonization device, including a heat exchanger, which is composed of a head 10, a cylinder 1 and a cylinder cover 9. The cylinder cover 9 is a hemispherical dome, the head 10 is an inverted cone structure, and the cylinder 1 is a hollow cylindrical tubular structure. The spherical bottom of the cylinder cover 9 and the conical bottom of the head 10 are the same size as the cylindrical surface of the cylinder 1, so that the cylinder cover 9 is welded to the upper part of the cylinder 1, and the head 10 is welded to the lower part of the cylinder 1 to ensure the sealing of the heat exchanger itself.

[0030] Specific as Figure 1 As shown, a gas inlet 2 is provided at the top spherical center of the cylinder cover 9; a carbon dioxide outlet 6 is provided at the conical top of the end cap 10; a gas outlet 3, a nitrogen outlet 4, and a liquid nitrogen inlet 5 are provided on the outer surface of the cylinder 1, wherein the gas outlet 3 and the liquid nitrogen inlet 5 are arranged opposite to each other and on the side close to the end cap 10, the liquid nitrogen inlet 5 is higher than the gas outlet 3 in the horizontal direction; and the nitrogen outlet 4 is arranged on the side close to the cylinder cover 9, and is arranged in the same direction as the gas outlet 3 in the horizontal direction.

[0031] The heat exchanger body 1 is also provided with grids 7 evenly arranged in a tic-tac-toe pattern and condensing tubes 8 arranged in a serpentine pattern. The serpentine pattern can realize countercurrent heat exchange and increase heat exchange efficiency.

[0032] The grid 7 is arranged below the connection position between the cylinder cover 9 and the cylinder 1 , specifically at the welding position between the cylinder cover 9 and the cylinder 1 , and is located above the nitrogen outlet 4 , so that the gas entering the heat exchanger is evenly distributed in the cylinder 1 .

[0033] The condenser 8 is arranged below the grid 7, one end of which is connected to the nitrogen outlet 4, and the other end is connected to the liquid nitrogen inlet 5. The structure of the condenser 8 at the serpentine turn in the cylinder 1 is a right-angle connection structure with an arc, which helps to reduce flow resistance and solve the problem of uneven heat exchange.

[0034] How it works

[0035] During operation, the coal gas to be processed is introduced into the heat exchanger from the coal gas inlet 2, and then the coal gas is evenly distributed in the cylinder 1 through the grid 7. At the same time, liquid nitrogen is introduced into the condenser 8 from the liquid nitrogen inlet 5. The coal gas in the cylinder 1 is condensed and countercurrently heat-exchanged through the condenser 8, so that the water vapor, carbon disulfide, carbonyl sulfide, hydrogen sulfide, carbon dioxide, hydrogen chloride, etc. in the cylinder 1 are condensed into liquid, and carbon monoxide, nitrogen, hydrogen, etc. are always kept in a gaseous state. Relying on the density difference between gas and liquid, the liquid formed by the condensation of the coal gas is discharged from the carbon dioxide outlet 6 at the bottom. When the liquid nitrogen heats the coal gas, it is subjected to countercurrent heat exchange with the coal gas, gradually gasified, and flows out from the nitrogen outlet 4.

[0036] The above description is only the preferred embodiment of the utility model, and is not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A coal gas countercurrent heat exchange desulfurization and decarbonization device, characterized in that: include: A heat exchanger, comprising a cylinder cover, a cylinder and a head; the cylinder cover is arranged on the top of the cylinder, and the head is arranged on the lower part of the cylinder; the head is provided with a carbon dioxide outlet, the cylinder cover is provided with a gas inlet, and the outer surface of the cylinder is provided with a gas outlet, a nitrogen outlet, and a liquid nitrogen inlet; a grid and a condenser are provided in the cylinder; the cylinder cover, the cylinder and the head are connected by welding.

2. A coal gas countercurrent heat exchange desulfurization and decarbonization device as claimed in claim 1, characterized in that: The cylinder cover is a hemispherical dome, and the gas inlet is arranged at the top center of the sphere; the end cap is an inverted cone, and the carbon dioxide outlet is arranged at the top of the cone; the cylinder is a hollow cylindrical tubular structure.

3. The coal gas countercurrent heat exchange desulfurization and decarbonization device according to claim 1, characterized in that: The coal gas outlet and the liquid nitrogen inlet are relatively arranged on a side close to the sealing head.

4. A coal gas countercurrent heat exchange desulfurization and decarbonization device as claimed in claim 1, characterized in that: The liquid nitrogen inlet is higher than the coal gas outlet in the horizontal direction.

5. The coal gas countercurrent heat exchange desulfurization and decarbonization device according to claim 1, characterized in that: The nitrogen outlet is arranged on a side close to the cylinder cover and in the same direction as the horizontal direction of the gas outlet.

6. The coal gas countercurrent heat exchange desulfurization and decarbonization device according to claim 1, characterized in that: The grid is arranged below the connection position between the cylinder cover and the cylinder and above the nitrogen outlet.

7. The coal gas countercurrent heat exchange desulfurization and decarbonization device according to claim 1, characterized in that: The grids are evenly arranged in a well-shaped pattern inside the cylinder.

8. The coal gas countercurrent heat exchange desulfurization and decarbonization device according to claim 1, characterized in that: The condenser is arranged in a serpentine shape below the grid in the cylinder.

9. The coal gas countercurrent heat exchange desulfurization and decarbonization device according to claim 1, characterized in that: One end of the condenser is connected to a liquid nitrogen inlet, and the other end is connected to a nitrogen outlet.

10. The coal gas countercurrent heat exchange desulfurization and decarbonization device according to claim 1, characterized in that: The serpentine turning point of the condenser tube is a right-angle connection structure with an arc.

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