Water degassing device for gas-based shaft furnace

Abstract

The present application relates to a kind of water degassing device for gas-based shaft furnace, belong to hydrogen metallurgy technical field in metallurgical industry.Have the following technical solutions: the bottom of degassing cylinder (1) is connected with lower cone (12) and is integrated structure, degassing cylinder (1) is equipped with exhaust port (6) and water inlet (9), the top of degassing cylinder (1) is equipped with diffusion pipe (2), diffusion pipe (2) is equipped with sampling port (3) and nitrogen purging port (4);The bottom of lower cone (12) is connected with three-way valve (13), one outlet of three-way valve (13) is connected with blowdown valve (14), another outlet of three-way valve (13) is connected with water outlet pipe (19), and the water outlet of water outlet pipe (19) is located below normal working liquid level in degassing cylinder (1).The beneficial effects of the present application are: after using this degassing device, the content of waste gas at the backwater outlet reaches the safety standard, and the backwater is further treated, realizing the safe circulation of water, saving water resources and protecting the environment.

Description

TECHNICAL FIELD

[0001] The application relates to a water degassing device for a gas-based shaft furnace, and belongs to the field of hydrogen metallurgy in the metallurgical industry. BACKGROUND

[0002] Direct reduction ironmaking technology is a leading technology in the development of the steel industry. Its final product is iron and water, which reduces CO2 emissions. It is an important direction to reduce energy consumption, improve the structure of steel products, and improve the quality of steel products. It is also an important part of innovation and guidance in achieving the carbon peak target.

[0003] A large number of theories and practices have proved that in the gas-based shaft furnace direct reduction ironmaking technology, hydrogen metallurgy, which uses hydrogen as a reducing agent instead of carbon reducing agent, is an important development direction to ensure the high-quality, green and sustainable development of the steel industry, and adapts to the development of China's steel industry and manufacturing industry.

[0004] The reducing gas of the gas-based shaft furnace is recycled in the production process. The top gas discharged from the top of the shaft furnace after participating in the reduction reaction needs to be washed and purified for several times. A large amount of water is used for purifying gas. The backwater has a high pressure and a high content of waste gas in the water, including more than 60% of hydrogen and about 5% of carbon monoxide. If not treated, the backwater cannot be recycled. SUMMARY

[0005] The purpose of the present application is to provide a water degassing device for a gas-based shaft furnace, so that the content of waste gas at the backwater outlet reaches the safety standard, and the backwater is further treated to realize safe recycling of water and solve the problems in the background art.

[0006] The technical solution of the present application is:

[0007] A water degassing device for a gas-based shaft furnace comprises a degassing cylinder, a diffuser pipe, an exhaust port, a water inlet, a lower cone, a three-way valve, a blowdown valve and an outlet pipe. The bottom of the degassing cylinder is connected to the lower cone in an integrated structure. The degassing cylinder is provided with an exhaust port and a water inlet. The top of the degassing cylinder is provided with a diffuser pipe. The diffuser pipe is provided with a sampling port and a nitrogen purging port. The bottom of the lower cone is connected to the three-way valve. One outlet of the three-way valve is connected to the blowdown valve. The other outlet of the three-way valve is connected to the outlet pipe. The outlet of the outlet pipe is located below the normal working liquid level in the degassing cylinder.

[0008] A water baffle is arranged at a position inside the degassing cylinder opposite to the water inlet.

[0009] The water baffle is a right-angled shape.

[0010] The outlet pipe is connected to a backflushing pump through a branch pipe.

[0011] A gate valve C is arranged on the branch pipe of the outlet pipe. Gate valves A and B are respectively arranged on the outlet pipes on both sides of the branch pipe.

[0012] The upper end of the diffuser pipe extends to outside of the degassing cylinder, and the lower end of the diffuser pipe extends below the lowest liquid level in the degassing cylinder.

[0013] The sampling port on the diffuser pipe is located above the nitrogen purging port.

[0014] The degassing cylinder is provided with an infrared liquid level detector.

[0015] The exhaust port is located above the water inlet port, and a check valve is arranged behind the exhaust port.

[0016] In the direct reduction ironmaking in a gas-based shaft furnace, the process gas loop, the cooling gas loop, the coke oven gas loop and the used cooling and washing water are introduced into the degassing device through the water inlet port. In the degassing device, the water inlet pressure is converted from high pressure to normal pressure. The pressure change releases the waste gas dissolved in the water. The released waste gas is discharged upward through the exhaust port. The water from which the waste gas is removed flows downward and is discharged through the water outlet pipe to be treated in the next step.

[0017] The beneficial effects of the present application are that the water used for treating the reducing gas in the gas-based shaft furnace can be recycled after using the degassing device. 85,000 tons of waste water can be treated per year. According to the calculation of 2.45 yuan per ton of water, 20.8 million yuan can be saved per year, which saves water resources and protects the environment. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a sectional view of the present application;

[0019] In the figure: degassing cylinder 1, diffuser pipe 2, sampling port 3, nitrogen purging port 4, infrared liquid level detector 5, exhaust port 6, check valve 7, water baffle 8, water inlet port 9, gas detection alarm 10, manhole 11, lower cone 12, three-way valve 13, blowdown valve 14, gate valve A 15, gate valve B 16, gate valve C 17, backwash pump 18, water outlet pipe 19. DETAILED DESCRIPTION

[0020] The present application will be further described by examples in conjunction with the accompanying drawings.

[0021] Referring to the accompanying Figure 1The utility model relates to a water degassing device for gas-based shaft furnace, which comprises a degassing cylinder 1, a diffusion pipe 2, an exhaust port 6, a water inlet 9, a lower cone 12, a three-way valve 13, a blowdown valve 14 and a water outlet pipe 19, the bottom of the degassing cylinder 1 is connected with the lower cone 12 as an integral structure, the degassing cylinder 1 is provided with the exhaust port 6 and the water inlet 9, the top of the degassing cylinder 1 is provided with the diffusion pipe 2, the diffusion pipe 2 is provided with a sampling port 3 and a nitrogen purging port 4, the bottom of the lower cone 12 is connected with the three-way valve 13, one outlet of the three-way valve 13 is connected with the blowdown valve 14, the other outlet of the three-way valve 13 is connected with the water outlet pipe 19, and the water outlet of the water outlet pipe 19 is located below the normal working liquid level in the degassing cylinder 1.

[0022] In the embodiment, reference is made to the accompanying drawings Figure 1 (1) the degassing cylinder 1 is a cylindrical cylinder made of a 15mm thick steel plate, and the diameter can be appropriately adjusted according to the amount of waste gas generated in the water treatment process in the production process, and in this example, the diameter of the degassing cylinder 1 is 1.5m.

[0023] (2) the process gas loop of the gas-based shaft furnace, the cooling gas loop, the coke oven gas loop and the used water are introduced into the degassing cylinder 1 through the water inlet 9, the water inlet 9 is provided with two, which are controlled by two pressure regulating valves, so that the water flow pressure and flow size when entering the degassing cylinder 1 can be controlled. The water flow enters from high pressure, usually above 1.5Mpa, and changes into normal pressure in the degassing cylinder 1. It is just by using this high normal pressure replacement that the waste gas dissolved in the water is released.

[0024] (3) a right-angled water baffle 8 is welded by a steel plate at the position opposite to the water inlet 9 in the degassing cylinder 1, and the water baffle 8 plays a role of water blocking and flow guiding in the specific work, so that the water flows into the lower part of the degassing cylinder 1 along the water baffle 8.

[0025] (4) the released waste gas is discharged upward through the exhaust port 6, the exhaust port 6 is arranged at the position 1.5-2.0m away from the upper part of the degassing cylinder 1, and is used for discharging the generated waste gas, a check valve 7 is arranged behind the exhaust port 6, which prevents the waste gas from flowing back, the check valve 7 is connected with the fire ring through a subsequent pipeline, and two sets of the exhaust port 6 and the check valve 7 are arranged for safety consideration, so as to prevent accidents caused by failure of one set and untimely treatment.

[0026] (5) under abnormal working conditions, due to blockage of the exhaust pipeline or abnormal increase of the released gas, the waste gas will continuously gather and cause serious danger if it cannot be discharged in time, so the diffusion pipe 2 is arranged in the degassing device. The diffusion pipe 2 is arranged in the degassing cylinder 1, the pipe diameter is 20cm, the lower end is located below the operating liquid level, and the upper part extends out of the top of the degassing cylinder 1, which is used as an emergency diffusion when the working liquid level is lower than the C position. Two diffusion pipes 2 are arranged for safety consideration.

[0027] (6) Especially as the emergency release of waste gas, the release pipe 2 on the upper outlet position set height should not be less than 45 m, to ensure the safety of the surrounding environment and personnel.

[0028] (7) The water after releasing waste gas downward through the degassing cylinder 1 lower part of the lower cone 12, the lower cone 12 set angle of repose 70 ~ 80º, facilitate the sludge and other impurities generated in the process of water treatment can be along the lower cone 12 inner wall down without gathering in the cone wall.

[0029] (8) In the degassing cylinder 1 lower part position open 1 m long square manhole 11, for maintenance inside the degassing device inspection and dredging work, before entering the water discharge clean, the internal nitrogen purge the whole exhaust device, gas safety detection, detection gas meet the requirements can enter.

[0030] (9) In the manhole 11 and tee valve 13 near the setting of two wall mounted single point toxic gas detection alarm 10, type VTD110, used in the two places maintenance operation and personnel point inspection process safety protection.

[0031] (10) Nitrogen purge port 4 near the sampling port 3 lower part of the setting, for maintenance inside the degassing device harmful gas purge replacement, in actual operation, can take a replacement port replacement, in order to speed up the replacement progress, can also be two purge port blowing replacement operation.

[0032] (11) Sampling port 3 set in the release pipe 2 upper position, set the stop valve reliable control, as maintenance or temporary sampling analysis, only from the sampling port 3 gas sample qualified, maintenance personnel can carry out various maintenance work.

[0033] (12) The operating range of the liquid level h1 is determined by the amount of waste gas released in the water system during production, the pressure at the top of the degassing device, and the water flow pressure of the outlet pipe. The operating range is normally controlled between 1.5 and 2.0 m, and can be adjusted appropriately according to the specific production process to ensure appropriate water flow pressure and meet the normal water system circulation treatment. The control of the liquid level is realized by controlling the pressure regulating valve at the front end of the inlet.

[0034] (13) The lower part of the lower cone 12 is connected to the tee valve 13 through a short channel, and the tee valve 13 is connected to the blowdown valve 14 at the lower part. The sludge and other impurities generated during the high pressure conversion process in the degassing device are discharged through the blowdown valve 14. The blowdown valve 14 is set as close as possible to the tee valve 13 to facilitate the discharge of sludge and impurities. The discharge period is determined according to the amount of sludge and impurities generated in the specific production process.

[0035] (14) The other outlet of the three-way valve 13 is used for water outlet, and the water outlet end of the three-way valve 13 is connected with the water outlet pipe 19. The water from the water outlet pipe 19 will enter the subsequent treatment process for next step treatment. The water outlet pipe 19 is connected through two right-angle elbows, and the upward turning height is not less than 3m, so as to ensure the safe and reliable water seal function of the lower cone, pipe and valve.

[0036] (15) The backwashing pump 18 is located near the horizontal section of the water outlet pipe 19, and is connected with the water outlet pipe 19 through a valve and a water pipe. The backwashing pump 18 is used for backwashing the three-way valve 13 and the water outlet pipe 19 regularly, and can also be used for treating the blockage accident caused by the increase of sludge under abnormal conditions, so as to ensure the smoothness of the pipeline.

[0037] (16) In the specific operation, if the three-way valve 13, the lower cone 12 and other parts need to be flushed, first, close the valve at the water inlet 9, then close the gate valve B16, open the blowdown valve 14 for temporary drainage, open the gate valve C17, and start the backwashing pump 18 for flushing operation. After the water is clean, close the backwashing pump and the corresponding gate valve to end the flushing. If the water outlet pipe 19 and the two connecting elbows need to be flushed, first, close the gate valve A15, open the gate valve B16, and start the backwashing pump 18 for flushing operation. After the water is clean, close the backwashing pump and the corresponding gate valve to end the flushing.

[0038] (17) Two infrared liquid level detectors 5 are installed at the top of the degassing cylinder 1, which are used for detecting the working liquid level during production. When the liquid level exceeds the A position or is lower than the B position, an alarm is set in the operation room host, and the working personnel adjusts the water inlet pressure according to the situation. When the liquid level is lower than the C position, an alarm is given to indicate that the exhaust gas exceeds the specified pressure, and the relief is opened for work. The working personnel needs to confirm and troubleshoot.

[0039] 6、Implementation effect

[0040] After using the degassing device, the water used for treating the gas-based shaft furnace reducing gas can be recycled, and 85,000 tons of waste water can be treated per year. According to the calculation of 2.45 yuan per ton of water, the annual cost saving is 20.8 million yuan, which saves water resources and protects the environment.

Claims

1. A water degassing device for a gas-based vertical shaft furnace, characterized in that: It includes a degassing cylinder (1), a vent pipe (2), an exhaust port (6), a water inlet (9), a lower cone (12), a three-way valve (13), a drain valve (14), and a water outlet pipe (19). The bottom of the degassing cylinder (1) is connected to the lower cone (12) as an integral structure. The degassing cylinder (1) is provided with an exhaust port (6) and a water inlet (9). The top of the degassing cylinder (1) is provided with a vent pipe (2). The vent pipe (2) is provided with a sampling port (3) and a nitrogen purging port (4). A baffle plate (8) is provided inside the degassing cylinder (1) directly opposite the water inlet (9). (8) is a right angle; the bottom of the lower cone (12) is connected to a three-way valve (13), one outlet of the three-way valve (13) is connected to a drain valve (14), and the other outlet of the three-way valve (13) is connected to a water outlet pipe (19). The outlet of the water outlet pipe (19) is located below the working liquid level in the degassing cylinder (1). The water outlet pipe (19) is connected to the backwash pump (18) through a branch pipe. A gate valve C (17) is provided on the branch pipe of the water outlet pipe (19). Gate valves A (15) and B (16) are provided on the water outlet pipes (19) on both sides of the branch pipe, respectively. The upper end of the venting pipe (2) extends outside the degassing cylinder (1), and the lower end of the venting pipe (2) extends below the liquid level inside the degassing cylinder (1).

2. The water degassing device for a gas-based vertical shaft furnace according to claim 1, characterized in that: The sampling port (3) on the venting tube (2) is located above the nitrogen purging port (4).

3. The water degassing device for a gas-based vertical shaft furnace according to claim 1, characterized in that: The degassing cylinder (1) is equipped with an infrared liquid level detector (5).

4. The water degassing device for a gas-based vertical shaft furnace according to claim 1, characterized in that: The vent (6) is located above the inlet (9), and a check valve (7) is provided behind the vent (6).

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