Tar residue treatment device of pre-separator of tar and ammonia water separation system

Abstract

The invention discloses a tar residue treatment device for a pre-separator of a tar and ammonia water separation system, which comprises the pre-separator connected with a tar and ammonia water mixture pipeline, and further comprises a primary particle size optimization device, a pre-treater, a secondary particle size optimization device and a dehydration device, the primary particle size optimization device is communicated with the preseparator through an inlet pipeline of the primary particle size optimization device, the preprocessor is connected with the primary particle size optimization device through a conveying pipeline, the secondary particle size optimization device is connected below the preprocessor and connected with the dehydration device, the bottom of the dehydration device is connected with the tar residue box, and the tar residue box is connected with the preprocessor. The outlet end of the ammonia water tank is connected with the pre-separator through an ammonia water return pipeline, and an ammonia water injection port is formed in the top of the secondary particle size optimization device. The tar residue treatment device of the pre-separator of the tar and ammonia water separation system can realize harmless continuous treatment of the source and the tail end of the tar residue, and reduces safety and environmental protection hidden dangers of the tar residue in a series of cleaning and treatment processes.

Description

Technical Field

[0001] The present invention relates to the technical field of coke oven gas purification, and specifically to a device for disposing tar residue in a pre-separator of a tar-ammonia water separation system. Background Art

[0002] In a coke oven gas purification system, a tar-ammonia water separation process is usually set at the source, equipped with a tar-ammonia water pre-separation system. That is, in the pre-separation system, automatic sedimentation separation of tar, ammonia water, and tar residue is achieved by using the different densities of the tar-ammonia water mixture. Currently, the general method for disposing of tar residue in the pre-separator system is to break it with a squeezing pump and then recycle it until the particle size of the tar residue drops below 8 mm; another method is to manually discharge it into the underground tank. The tar residue generated by the system belongs to hazardous solid waste, with poor fluidity and is prone to causing corrosion and adhesion of subsequent equipment and facilities.

[0003] Both of the above-mentioned methods for discharging and disposing of tar residue have certain problems. Although the particle size of the tar residue broken by the squeezing pump is small enough, it is easy to cause blockage at the bottom of the tar-ammonia water separation tank during the system circulation process, resulting in passive production of the system. The manual slag discharge method also has the problem that blockage at the bottom of the tar-ammonia water separation tank occurs due to untimely discharge. The tar residue finally deposited in the underground tank needs to be regularly cleaned manually, which involves limited space operations and poses safety hazards. At the same time, a large amount of VOCs gas generated during the operation also has a certain impact on the surrounding environment and personnel. The tar residue with a large water content is also prone to causing various pollutions and even affecting the normal operation of the belt system during the coal blending process.

[0004] Such as Figure 1 、 Figure 2 shown, the old system is a tar-ammonia water separation system supporting the 7# and 8# coke ovens in the northern area of Magang, and the new system is a tar-ammonia water separation system supporting the 9# and 10# coke ovens in the northern area of Magang; to alleviate the problem of blockage of large tar lumps in the system, the tar residue at the bottom of the pre-separator of the old system needs to be manually discharged to the sump in the tar-ammonia water tank area regularly; the original design of the pre-separator of the new system is equipped with a squeezing pump, which breaks the large tar lumps and recycles them into the pre-separator until the particle size of the large tar lumps meets the subsequent production requirements. However, in the actual production process, due to the continuous circulation and accumulation of tar residue in the tar-ammonia water system, the system is also blocked. As a result, two additional manual slag discharge pipelines are added, and the slag is manually discharged to the tar-ammonia water sump regularly.

[0005] The wet tar residue in the above-mentioned tar-ammonia water sump needs to be manually cleaned regularly, which poses a series of safety and environmental protection hazards.

[0006] By using the method of the present invention, the source and end disposal of tar residue in the tar-ammonia separation system can be realized, effectively alleviating the blockage at the bottom of the tar-ammonia separation tank, reducing the manual discharge of tar residue, manual cleaning of the tar residue pit and manual mixing of tar residue with coal for coal blending. The harmless and short and flat treatment of tar residue in the tar-ammonia separation system is realized. At the same time, the wet tar in the tar residue is recovered to increase the product benefit. In addition, the dehydrated tar residue is more suitable for coal blending and coking. Compared with coal blending and coking with wet tar residue, the heat consumption for coking can be reduced and the energy consumption can be saved. Summary of the Invention

[0007] The purpose of the present invention is to provide a device for disposing of tar residue in a pre-separator of a tar-ammonia separation system to solve the problems raised in the above-mentioned background technology.

[0008] To achieve the above purpose, the present invention provides the following technical solution: A device for disposing of tar residue in a pre-separator of a tar-ammonia separation system includes a pre-separator, which is connected to a tar-ammonia mixture pipeline. It also includes a primary particle size optimization device, a pre-processor, a secondary particle size optimization device, and a dehydration device. The primary particle size optimization device and the pre-separator are connected through a primary particle size optimization device inlet pipeline. The pre-processor and the primary particle size optimization device are connected through a conveying pipeline. The pre-processor is connected to the secondary particle size optimization device below. The secondary particle size optimization device is connected to the dehydration device. The bottom of the dehydration device is connected to a tar residue tank, and the side is connected to an ammonia water tank. The outlet end of the ammonia water tank is connected to the pre-separator through a return ammonia water pipeline. An ammonia water injection port is provided at the top of the secondary particle size optimization device for injecting ammonia water to clean the pipeline. The pre-processor and the dehydration device are jointly connected to an exhaust gas pipeline.

[0009] Preferably, a booster pump is installed on the conveying pipeline, a tar residue conveying pump is installed on the pipeline connecting the secondary particle size optimization device and the dehydration device, and an ammonia water conveying pump is installed on the return ammonia water pipeline.

[0010] Preferably, a temperature measuring instrument, an interface measuring instrument and a liquid level regulating valve are provided on the pre-processor. The liquid level regulating valve is used to control the ammonia water feeding amount from the ammonia water tank to the pre-processor. The liquid level regulating valve is connected to a return ammonia water pipeline, and the other end of the return ammonia water pipeline is connected to the pre-separator.

[0011] Preferably, a steam pipeline is provided outside the pre-processor for heating the medium inside the pre-processor, and the end of the steam pipeline is connected to a water treatment system.

[0012] Preferably, a crushing module and a screening module are provided in the primary particle size optimization device and the secondary particle size optimization device. The crushing module is used to crush large tar residues, and the screening module is used to screen tar residue particles with a particle size smaller than the standard.

[0013] Preferably, a stirring module is provided inside the pre-processor to prevent the tar residue from caking due to high viscosity.

[0014] Preferably, a filtering module and a pressure filtration module are arranged in the residue dehydration device. The pressure filtration module is used to dehydrate the tar residue, the filtering module filters out the tar residue, and an openable and closable channel is arranged between the dehydration device and the tar residue tank.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0016] The large tar residues deposited at the bottom of the pre-separator system become small tar residues with a diameter not exceeding 10 mm after passing through the first-stage particle size optimization device for tar residues, and are sent to the subsequent pre-processor by a pump. There is a tar-ammonia water mixture stored inside, and steam insulation is configured outside to ensure a constant temperature inside the device. A stirring device is arranged inside the device to ensure good fluidity of the tar-ammonia water mixture inside the device. The outlet of the pre-processor is connected to the second-stage particle size optimization device for tar residues. The tar residues after two-stage particle size optimization are sent to the tar residue dehydration device. The separated tar-ammonia water is sent back to the tar recovery system, and the tar residues with less water content after dehydration are sent to the coking coal blending. The off-gas generated by the system is collected uniformly and treated centrally. This method can achieve harmless and continuous disposal of tar residues at the source and the end, and reduce the safety and environmental protection hazards existing in a series of cleaning and treatment processes of tar residues. Description of the Drawings

[0017] Figure 1 It is a schematic flow chart of the present invention;

[0018] Figure 2 It is a schematic flow chart of the treatment process of tar residues in the old system without a squeezing pump;

[0019] Figure 3 It is a schematic flow chart of the treatment process of tar residues in the new system with a squeezing pump.

[0020] In the figure: 1. Tar-ammonia water mixture pipeline; 2. Pre-separator; 3. Inlet pipeline of the first-stage particle size optimization device; 4. First-stage particle size optimization device; 5. Boosting pump; 6. Conveying pipeline; 7. Pre-processor; 8. Second-stage particle size optimization device; 9. Tar residue conveying pump; 10. Dehydration device; 11. Tar residue tank; 12. Ammonia water tank; 13. Ammonia water conveying pump; 14. Return ammonia water pipeline; 15. Steam pipeline; 16. Water treatment system; 17. Exhaust gas pipeline; 18. Return ammonia water pipeline; 19. Liquid level regulating valve; 20. Temperature measuring instrument; 21. Interface measuring instrument; 22. Ammonia water injection port. Detailed Embodiments

[0021] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0022] See Figure 1 , which is a schematic process flow diagram of a method for disposing tar residue in a pre-separator of a tar-ammonia separation system of the present invention. It mainly includes a primary particle size optimization device 4, a booster pump 5, a pre-processor 7, a secondary particle size optimization device 8, a transfer pump 9, a dehydration device 10, and a tar residue tank 11. The upper inlet pipe of the primary particle size optimization device 4 is connected to the outlet of the pre-separator 2, the bottom outlet pipe of the primary particle size optimization device 4 is connected to the inlet of the booster pump 5, the outlet of the booster pump 5 is connected to the inlet pipe of the pre-processor 7. A tar residue stirring device is configured in the pre-processor 7 and is driven by a motor to prevent the internal tar residue from caking. The bottom of the pre-processor 7 is of a conical structure. A liquid level regulating valve 19 is provided at the upper part of the pre-processor 7 to keep the liquid level in the pre-processor 7 constant. When the liquid level exceeds the liquid level regulating valve 19, it flows into the pre-separator 2 through the reflux ammonia pipe 14. A temperature measuring instrument 20 is provided at the bottom of the pre-processor 7 to keep the temperature in the pre-processor 7 up to standard. An interface measuring instrument 21 is provided at the bottom of the pre-processor 7 to be used for real-time detection of the stratification interface positions of tar, ammonia water, and tar residue, ensuring the efficient separation of the three and assisting in automatic slag discharge. The bottom outlet pipe of the pre-processor 7 is connected to the inlet of the secondary particle size optimization device 8. An ammonia water injection port 22 is also provided at the inlet of the secondary particle size optimization device 8 to prevent pipeline blockage and can also be cleaned with steam, preferably with ammonia water. The ammonia water injection port 22 is connected to an external ammonia water flushing valve. A crushing module and a screening module are arranged in the two particle size optimization devices. The crushing module is used for crushing large pieces of tar residue, and the screening module is used for screening tar residue particles with a particle size smaller than the standard. After the particle size of the tar residue is optimized in two stages, it is sent to the dehydration device 10 by the tar residue transfer pump 9. An exhaust port is provided at the top of the dehydration device 10 for exhausting waste gas, a drain port is provided in the middle for discharging the ammonia water removed from the tar residue, and a slag discharge port is provided at the bottom and is connected to the inlet of the tar residue tank 11. The tar residue in the tar residue tank 11 is sent out regularly.

[0023] Description of the working principle of the present invention: The tar-ammonia water mixture generated from the coke oven flows into the pre-separator 2 automatically from the tar-ammonia water mixture pipeline 1. Due to different densities, it settles and separates automatically. The tar residue that settles into the inlet pipeline 3 of the first-stage particle size optimization device 4 is optimized into small-particle-size tar residue after passing through the first-stage particle size optimization device 4. After passing through the booster pump 5 and the conveying pipeline 6, it is sent to the pre-processor 7. A tar residue stirring device is configured in the pre-processor 7 to ensure the fluidity of the tar residue inside. After the liquid level of the tar residue in the pre-processor 7 reaches a certain height, the particle size of the tar residue is further reduced by the second-stage particle size optimization device 8 and then sent to the dehydration device 10 by the tar residue conveying pump 9. The dehydrated tar residue slides down to the tar residue box 11 and is regularly mixed with coal. The waste gas in the dehydration device 10 is collected and treated uniformly through the waste gas pipeline 17. The ammonia water generated by the tar residue dehydration device 10 flows into the ammonia water tank 12 automatically and is sent back to the pre-separator 2 by the ammonia water conveying pump 13 through the return ammonia water pipeline 18 to complete the closed-loop circulation. A steam pipeline 15 is provided outside the pre-processor 7 to ensure that the medium temperature in the pre-processor 7 meets the standard. The steam condensate generated due to steam condensation is sent to the water treatment system 16 uniformly.

[0024] Description of the operation process of the method of the present invention: When the tar and tar residue deposited at the bottom of the pre-processor 7 reach a certain liquid level, the following operations are automatically carried out in sequence:

[0025] (1) Start the ammonia water conveying pump 13;

[0026] (2) Start the dehydration device 10 after the ammonia water conveying pump 13 is started and runs for 10 seconds;

[0027] (3) Start the second-stage particle size optimization device 8 and the tar residue conveying pump 9 after the tar residue dehydration device 10 is started and runs for 30 seconds;

[0028] (4) Open the ammonia water flushing valve to flush the pipeline and equipment for 300 seconds, and then close the valve after flushing;

[0029] (5) Open the bottom valve of the tar residue pre-processor 7 for discharging slag. The specific opening amplitude of the bottom valve of the tar residue pre-processor 7 is: 30% → 50% → 80%, with an interval of 10 seconds each time;

[0030] (6) Close the bottom valve of the pre-processor 7 when the liquid level of the pre-processor 7 drops to about 100 mm;

[0031] (7) Keep the dehydration device 10 running until no dry slag falls into the tar residue box 11;

[0032] (8) Open the ammonia water flushing valve to an opening of 35% to flush the pipeline and equipment for 500 seconds, and then close the ammonia water flushing valve after flushing;

[0033] (9) After the ammonia water flushing valve is closed for 30 seconds, stop the tar residue transfer pump 9 and the tar residue secondary particle size optimization device 8.

[0034] (10) After the tar residue transfer pump 9 and the tar residue secondary particle size optimization device 8 are stopped for 30 seconds, stop the tar residue dehydration device 10, and stop the ammonia water transfer pump 13 after 60 seconds.

[0035] Among them, the tar residue deposited at the bottom of the pre-processor in step (5) may form lumps due to incomplete stirring or local caking. If the valve is suddenly fully opened, large pieces of slag are likely to get stuck at the pipe inlet or block downstream equipment (such as the secondary particle size optimization device and the transfer pump). Open in stages: first discharge small particle slag and better-flowing mixtures at 30% opening, gradually break or soften large pieces of slag, and then increase the opening to discharge the remaining materials to avoid sudden blockage.

[0036] Step (8) is to remove the residual materials in the pipeline, prevent blockage, ensure the cleanliness of the equipment, and extend the service life. The flushing parameters are: opening 35% (to avoid excessive flow impact on the equipment), duration 500 seconds (to ensure sufficient flushing), and optimize the flushing intensity according to the viscosity of the tar residue and the system scale.

[0037] The delayed shutdown in step (9) is to allow the flushing liquid in the pipeline and equipment to be completely discharged, avoiding the deposition of residual ammonia water or materials after shutdown. If directly shut down, it may cause the flushing liquid to stay, mix with the residual tar residue to form a gel, and instead increase the risk of blockage. The 30-second delay provides a buffer time for the system to ensure the stability of the feedback signals from sensors (such as level gauges and pressure gauges), and avoid control logic confusion caused by unsynchronized equipment states.

[0038] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A device for disposing of tar residue in a pre-separator of a tar-ammonia water separation system, comprising a pre-separator (2), the pre-separator (2) being connected to a tar-ammonia water mixture pipeline (1), characterized in that: It also includes a primary particle size optimization device (4), a pre-processor (7), a secondary particle size optimization device (8), and a dehydration device (10). The primary particle size optimization device (4) and the pre-separator (2) are connected through a primary particle size optimization device inlet pipe (3). The pre-processor (7) and the primary particle size optimization device (4) are connected through a conveying pipe (6). The secondary particle size optimization device (8) is connected below the pre-processor (7). The secondary particle size optimization device (8) and the dehydration device (10) are connected. The bottom of the dehydration device (10) is connected to a tar residue tank (11), and the side is connected to an ammonia water tank (12). The outlet end of the ammonia water tank (12) is connected to the pre-separator (2) respectively through a recycled ammonia water pipe (18). An ammonia water injection port (22) is provided at the top of the secondary particle size optimization device (8) for injecting ammonia water to clean the pipeline. The pre-processor (7) and the dehydration device (10) are jointly connected to an exhaust gas pipe (17).

2. The tar residue disposal device of the pre-separator in the tar and ammonia separation system according to claim 1, wherein: A booster pump (5) is installed on the conveying pipe (6), and a tar residue transfer pump (9) is installed on the pipeline connecting the secondary particle size optimization device (8) and the dehydration device (10). An ammonia water transfer pump (13) is installed on the recycled ammonia water pipe (18).

3. The pre-separator tar residue disposal device of the tar and ammonia water separation system according to claim 2, characterized in that: A temperature measuring instrument (20), an interface measuring instrument (21), and a liquid level regulating valve (19) are provided on the pre-processor (7). The liquid level regulating valve (19) is used to control the ammonia water feed amount from the ammonia water tank (12) to the pre-processor (7). The liquid level regulating valve (19) is connected to a recycled ammonia water pipe (14), and the other end of the recycled ammonia water pipe (14) is connected to the pre-separator (2).

4. The pre-separator tar residue disposal device of the tar and ammonia separation system according to claim 3, characterized in that: A steam pipe (15) is provided outside the pre-processor (7) for heating the medium inside the pre-processor (7). The end of the steam pipe (15) is connected to a water treatment system (16).

5. The pre-separator tar residue disposal device of the tar and ammonia water separation system according to claim 4, characterized in that: A crushing module and a screening module are provided inside the primary particle size optimization device (4) and the secondary particle size optimization device (8). The crushing module is used to crush large tar residues, and the screening module is used to screen tar residue particles with a particle size smaller than the standard.

6. The tar residue disposal device of the pre-separator in the tar and ammonia separation system according to claim 5, characterized in that: A stirring module is provided inside the pre-processor (7) to prevent the tar residues from caking due to high viscosity.

7. The pre-separator tar residue disposal device of the tar and ammonia water separation system according to claim 6, characterized in that: A filtering module and a pressure filtering module are provided inside the slag dehydration device (10). The pressure filtering module is used to dehydrate the tar residues, and the filtering module filters the tar residues. An openable channel is provided between the dehydration device (10) and the tar residue tank (11).

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