Drainage water recycling device of coke oven raw gas waste heat utilization system

Abstract

The invention discloses a blow-down water recycling device of a coke oven raw gas waste heat utilization system. The blow-down water recycling device comprises a steam pocket, a deaerator, a blow-down flash tank and a blow-down water tank, a drain outlet at the bottom of the steam drum is communicated with the blowdown flash tank, one end of the steam drum continuous blowdown pipeline extends into the steam drum and is higher than the drain outlet at the bottom of the steam drum, the steam drum is further communicated with the blowdown flash tank through a steam drum overflow pipeline, and one end of the steam drum overflow pipeline extends into the steam drum; a drain outlet in the bottom of the deaerator is communicated with a blowdown flash tank, and the inside of the steam pocket is communicated with the blowdown flash tank; sewage draining outlets in the bottoms of the sewage draining flash tanks are all higher than a water seal system of the coke oven ascending pipe; the blowdown flash tank is communicated with a blowdown water tank, and a blowdown outlet of the blowdown water tank is communicated with a water seal system of the coke oven riser. According to the invention, sewage enters the steam pocket and is introduced into the blowdown flash tank through the continuous blowdown pipeline and the periodic blowdown pipeline, and after the blowdown flash tank is expanded, high-concentration salt-containing water in the blowdown water is fed into the recovery system, so that the cyclic utilization of heat energy and demineralized water is realized.

Description

Technical Field

[0001] The present invention relates to the field of wastewater recycling of a coke oven raw gas waste heat utilization system. More specifically, the present invention relates to a wastewater recycling device of a coke oven raw gas waste heat utilization system. Background Art

[0002] At present, the technical transformation of waste heat recovery of coke oven raw gas riser in coking enterprises is an important topic for the country to implement energy conservation and emission reduction. The waste heat recovery and utilization system includes saturated steam heat exchanger group, superheated steam heat exchanger group, steam drum with steam-water separator and circulating water pump group and feed water pump group, condensing ammonia water heater, condensing rich oil heater, ammonia evaporation tower and debenzene tower.

[0003] The research on waste heat recovery and utilization system carried out by coking enterprises is not only environmentally friendly and energy-saving, but also has significant economic benefits. It can not only improve the waste heat utilization rate of the enterprise, but also reduce carbon emissions and waste gas emissions, and can also generate economic value by supplying steam to the outside.

[0004] In the actual production process of the coke oven waste gas riser waste heat utilization system, in order to maintain the system water quality, 2%~4% of the total water supply and a certain amount of fixed discharge are used for boiler water replacement, and the drum wastewater directly enters the ditch of the coking enterprise, and is all treated as sewage for external discharge. The sewage treatment volume is huge, which causes huge costs and burdens on production. The sewage discharged by the riser waste heat utilization system contains huge heat and the water temperature is relatively high. This large amount of heat cannot be used, which will cause great waste, especially in the water-scarce northern regions (Inner Mongolia, Xinjiang, Gansu, Hebei, etc.). Such high-quality sewage (desalted water) is directly discharged into the ditch, which will cause waste of high-quality water resources.

[0005] Chinese invention patent CN 118066525 A "A device and method for cascade utilization of waste heat and waste water from dry coke quenching boiler" filters the waste water discharged from the dry coke quenching boiler, heats it up through a heat pump system, and gradually utilizes the heat contained therein. After the heat is fully utilized, it is used as supplementary water for the coke oven riser water tank, the coke oven pusher tail coke cleaning machine water tank, the coke oven pusher dust removal water seal tank, and the coke quenching water pool, reducing the use of new water resources. The system is reasonably configured, but the system is complex and does not conform to the characteristics of the coke oven riser waste heat utilization system, and cannot solve the problem of low-cost recovery of waste water during waste heat utilization. Summary of the invention

[0006] In order to achieve these purposes and other advantages according to the present invention, a preferred embodiment of the present invention provides a wastewater recycling device for a coke oven raw gas waste heat utilization system, comprising a steam drum, a deaerator, a wastewater expansion container, and a wastewater tank; The steam drum is located above the deaerator and the blowdown expansion tank, the deaerator is located above the blowdown tank, the blowdown tank is located above the coke oven riser, the coke oven riser is connected to the top of the coke oven and communicates with the inside of the coke oven; The drain port at the bottom of the drum is connected to the drain expansion tank through a drum periodic drain pipe, and the inside of the drum is also connected to the drain expansion tank through a drum continuous drain pipe, one end of the drum continuous drain pipe extends into the drum and is higher than the drain port at the bottom of the drum, and the inside of the drum is also connected to the drain expansion tank through a drum overflow pipe, one end of the drum overflow pipe extends into the drum and is higher than one end of the drum continuous drain pipe extending into the drum; The sewage outlet at the bottom of the deaerator is connected to the sewage expansion tank through the sewage pipe of the deaerator, and the steam drum is also connected to the sewage expansion tank through the overflow pipe of the deaerator. One end of the sewage pipe of the deaerator extends into the deaerator and is higher than the sewage outlet at the bottom of the deaerator. The sewage outlet at the bottom of the steam drum and the sewage outlet at the bottom of the sewage expansion tank are both higher than the water seal system of the coke oven riser; The sewage expansion container is connected to a sewage tank, and the sewage outlet of the sewage tank is connected to the water seal system of the coke oven riser.

[0007] According to a preferred embodiment of the present invention, the steam outlet at the top of the blowdown expansion tank is connected to the desalted water tank through a steam pipe.

[0008] According to a preferred embodiment of the present invention, the sewage tank is first connected to the water seal system of the coke oven riser and then connected to the water treatment workshop.

[0009] According to a preferred embodiment of the present invention, a first liquid level meter is installed at one end of the drum overflow pipe located in the drum.

[0010] According to a preferred embodiment of the present invention, the drum periodic blowdown pipe, the drum continuous blowdown pipe, the drum overflow pipe, the deaerator blowdown pipe and the deaerator overflow pipe are all equipped with valves.

[0011] According to a preferred embodiment of the present invention, the steam drum is 15 to 35 meters higher than the coke oven riser.

[0012] According to a preferred embodiment of the present invention, a second liquid level meter is provided in the sewage expansion tank to monitor the liquid level in the sewage expansion tank in real time, and a solenoid valve is provided at the sewage outlet of the sewage expansion tank.

[0013] According to a preferred embodiment of the present invention, the solenoid valve is connected to a PLC controller for control. When the second liquid level meter detects that the water level in the sewage expansion tank reaches a preset value, the PLC controller controls the solenoid valve to open to discharge sewage.

[0014] The present invention includes at least the following beneficial effects: The present invention provides a wastewater recycling device for a waste heat utilization system of a coke oven gas, wherein the wastewater generated by the waste heat recovery system enters the drum through a continuous wastewater pipe and a periodic wastewater pipe, and is introduced into a wastewater expansion tank device, and after expansion through the wastewater expansion tank, the high-concentration salt water in the wastewater is sent to the recovery system, and the wastewater expansion steam is collected and recovered through an insulation pipe and returned to the desalted water tank in the waste heat recovery system, thereby realizing the recycling of heat energy and desalted water. The design of the device fully considers the actual coke oven production layout and daily operation, and the overall circulation system design is simple, energy-free, and green and environmentally friendly.

[0015] Compared with the prior art, the advantages of the present invention are: First, the present invention allows the sewage generated by the waste heat recovery system to enter the steam drum through the continuous sewage pipe and the periodic sewage pipe, and introduces the sewage into the sewage expansion tank equipment. After the sewage expansion tank is expanded, the high-concentration salt-containing sewage at the bottom is sent to the recovery system, and the sewage expansion steam is collected and recovered into the desalted water tank in the waste heat recovery system through the insulation pipe, so as to realize the recycling of heat energy and desalted water.

[0016] Second, the design of the present invention fully considers the coke oven production layout and daily operation reality, and the overall circulation system design is simple, energy-free, green and environmentally friendly, reducing the use of new water resources.

[0017] Third, in view of the actual situation of the coke oven, the present invention adopts an intermediate platform or end platform arrangement of a high-level steam drum and a blowdown expansion tank, that is, the blowdown outlet at the bottom of the steam drum and the blowdown expansion tank is arranged at a height higher than the coke oven riser operating platform, which provides favorable conditions for the waste heat utilization system of the raw gas riser to realize the natural circulation of steam and water under the condition of a coke oven power outage accident. At the same time, the sewage discharged from the sewage outlet of the blowdown expansion tank can be merged into the riser cover water seal system or the coke oven top smoke guide trough water seal system under the action of gravity. Compared with coking sewage, the sewage has better water quality and is a very ideal water for water seal. After the sewage flows through the water seal system, the sewage is finally merged into the sewage sedimentation tank to realize direct utilization of the water circulation system without the need to set a circulation pump. The system is energy-saving, green and environmentally friendly.

[0018] In summary, the present invention can realize the effective recovery of wastewater in the water circulation system of the coke oven riser waste heat utilization system, and has the characteristics of small investment, intelligence, energy saving and water saving, and good environmental protection.

[0019] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of the wastewater recovery and utilization device of the coke oven raw gas waste heat utilization system in the present invention. DETAILED DESCRIPTION

[0021] The present invention is further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0022] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art can think of other obvious variations. The basic principles of the present invention defined in the following description can be applied to other embodiments, variations, improvements, equivalents, and other technical solutions that do not deviate from the spirit and scope of the present invention.

[0023] Those skilled in the art should understand that, in the disclosure of the present invention, the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the above terms should not be understood as limiting the present invention.

[0024] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0025] like Figure 1 As shown, a preferred embodiment of the present invention provides a wastewater recycling device for a coke oven gas waste heat utilization system, comprising a steam drum 1, a deaerator 2, a wastewater expansion container 3, and a wastewater tank 4; The steam drum 1 is located above the deaerator 2 and the blowdown expansion tank 3, the deaerator 2 is located above the blowdown tank 4, the blowdown tank 4 is located above the coke oven riser 5, the coke oven riser 5 is connected to the top of the coke oven 6 and communicates with the inside of the coke oven 6; The drain port at the bottom of the drum 1 is connected to the drain expansion tank 3 through the drum periodic drain pipe 7. The drum 1 is also connected to the drain expansion tank 3 through the drum continuous drain pipe 8. One end of the drum continuous drain pipe 8 extends into the drum and is higher than the drain port at the bottom of the drum 1. The drum is also connected to the drain expansion tank through the drum overflow pipe 14. One end of the drum overflow pipe extends into the drum and is higher than one end of the drum continuous drain pipe extending into the drum. The sewage outlet and the drainage outlet at the bottom of the deaerator 2 are connected to the sewage expansion tank 3 through the deaerator drainage pipe 13 and the deaerator sewage pipe 9 respectively. The steam drum 1 is also connected to the sewage expansion tank 3 through the deaerator overflow pipe 10. One end of the deaerator sewage pipe extends into the deaerator and is higher than the sewage outlet at the bottom of the deaerator. The sewage outlet at the bottom of the steam drum 1 and the sewage outlet at the bottom of the sewage expansion tank 3 are both higher than the water seal system of the coke oven riser 5; The sewage expansion container 3 is connected to the sewage tank, and the sewage outlet of the sewage tank 4 is connected to the water seal system of the coke oven riser.

[0026] In the above technical scheme, the sewage generated by the waste heat recovery system enters the steam drum through the continuous sewage pipe and the periodic sewage pipe, and is introduced into the sewage expansion tank equipment. After the sewage expansion tank is expanded, the high-concentration salt-containing sewage at the bottom is sent to the recovery system, and the sewage expansion steam is collected and recovered into the desalted water tank in the waste heat recovery system through the insulated pipe, so as to realize the recycling of heat energy and desalted water.

[0027] A high-position steam drum and blowdown expansion tank is arranged between platforms or at end platforms, that is, the blowdown outlet at the bottom of the steam drum and blowdown expansion tank is arranged at a height higher than the coke oven riser, which provides favorable conditions for the waste heat utilization system of the raw gas riser to realize the natural circulation of steam and water under the condition of a coke oven power outage accident. Water circulation can be achieved by gravity without the need for external power. At the same time, the sewage discharged from the sewage outlet of the blowdown expansion tank can be merged into the riser cover water seal system or the coke oven top smoke guide trough water seal system under the action of gravity. Compared with coking sewage, the sewage has better water quality and is an ideal water for water seal. After the sewage flows through the water seal system, it finally merges into the sewage sedimentation tank to realize direct utilization of the water circulation system. There is no need to set up a circulation pump. The system is energy-saving, green and environmentally friendly.

[0028] The steam outlet of the drum, the overflow of the drum, the periodic outlet of the drum, the continuous outlet of the drum, the drain outlet of the drum liquid level gauge, the drain outlet of the deaerator, the overflow of the deaerator, the drain outlet of the deaerator and other sewage are connected to the inlet of the sewage expansion tank after being converged; the steam outlet at the top of the sewage expansion tank is connected to the desalted water tank through a steam pipe; the sewage outlet at the bottom of the sewage expansion tank is connected to the water seal water tank on the top of the coke oven through a sewage pipe; the drain outlet and the overflow outlet at the bottom of the water seal water tank are connected to the subsequent water use system, such as the water seal water system on the top of the coke oven riser heat exchanger and the water seal pipe system of the smoke guide trough on the top of the coke oven.

[0029] According to a preferred embodiment of the present invention, the steam outlet at the top of the blowdown expansion vessel is connected to the desalted water tank through a steam pipe, so that the high-concentration salt-containing blowdown water at the bottom can be sent to the desalted water tank.

[0030] According to a preferred embodiment of the present invention, the sewage tank 4 is first connected to the water seal system of the coke oven riser, and then connected to the water treatment workshop 11, so that the water in the sewage tank is discharged into the sewage tank. And the sewage from the sewage expansion tank can be discharged to the water treatment workshop of the coking enterprise through a gravity pipe nearby, so as to realize the recovery of high-quality water resources.

[0031] According to a preferred embodiment of the present invention, a first liquid level meter 12 is installed at one end of the drum overflow pipe located in the drum for real-time monitoring of the water level in the drum.

[0032] According to a preferred embodiment of the present invention, the steam drum periodic blowdown pipe, steam drum continuous blowdown pipe, steam drum overflow pipe, deaerator blowdown pipe and deaerator overflow pipe are all equipped with valves, and the valves here can be solenoid valves for easy control and adjustment.

[0033] According to a preferred embodiment of the present invention, the steam drum is 15 to 35 meters higher than the coke oven riser.

[0034] According to a preferred embodiment of the present invention, a second liquid level meter is provided in the sewage expansion tank to monitor the liquid level in the sewage expansion tank in real time, and a solenoid valve is provided at the sewage outlet of the sewage expansion tank, which can be opened and closed by a controller as needed, thereby achieving the purpose of automatically controlling the discharge of water.

[0035] According to a preferred embodiment of the present invention, the solenoid valve is connected to a PLC controller for control. When the second liquid level meter detects that the water level in the sewage expansion tank reaches a preset value, the PLC controller controls the solenoid valve to open to discharge sewage.

[0036] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes, and they can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A wastewater recycling device for a coke oven gas waste heat utilization system, characterized in that: Including steam drum, deaerator, blowdown expansion tank, and sewage tank; The steam drum is located above the deaerator and the blowdown expansion tank, the deaerator is located above the blowdown tank, the blowdown tank is located above the coke oven riser, the coke oven riser is connected to the top of the coke oven and communicates with the inside of the coke oven; The drain port at the bottom of the drum is connected to the drain expansion tank through a drum periodic drain pipe, and the inside of the drum is also connected to the drain expansion tank through a drum continuous drain pipe, one end of the drum continuous drain pipe extends into the drum and is higher than the drain port at the bottom of the drum, and the inside of the drum is also connected to the drain expansion tank through a drum overflow pipe, one end of the drum overflow pipe extends into the drum and is higher than one end of the drum continuous drain pipe extending into the drum; The sewage outlet at the bottom of the deaerator is connected to the sewage expansion tank through the sewage pipe of the deaerator, and the steam drum is also connected to the sewage expansion tank through the overflow pipe of the deaerator. One end of the sewage pipe of the deaerator extends into the deaerator and is higher than the sewage outlet at the bottom of the deaerator. The sewage outlet at the bottom of the steam drum and the sewage outlet at the bottom of the sewage expansion tank are both higher than the water seal system of the coke oven riser; The sewage expansion container is connected to a sewage tank, and the sewage outlet of the sewage tank is connected to the water seal system of the coke oven riser.

2. The wastewater recycling device of the coke oven gas waste heat utilization system according to claim 1 is characterized in that: The steam outlet at the top of the blowdown expansion container is connected to the desalted water tank through a steam pipeline.

3. The wastewater recycling device of the coke oven gas waste heat utilization system according to claim 1 is characterized in that: The sewage tank is first connected to the water seal system of the coke oven riser and then connected to the water treatment workshop.

4. The wastewater recycling device of the coke oven gas waste heat utilization system according to claim 1 is characterized in that: A first liquid level meter is installed at one end of the drum overflow pipe located in the drum.

5. The wastewater recycling device of the coke oven gas waste heat utilization system according to claim 1 is characterized in that: The steam drum periodic blowdown pipeline, the steam drum continuous blowdown pipeline, the steam drum overflow pipeline, the deaerator blowdown pipeline and the deaerator overflow pipeline are all equipped with valves.

6. The wastewater recycling device of the coke oven gas waste heat utilization system according to claim 1 is characterized in that: The steam drum is 15 to 35 meters higher than the coke oven riser.

7. The wastewater recycling device of the coke oven gas waste heat utilization system according to claim 1 is characterized in that: A second liquid level meter is arranged in the sewage expansion tank to monitor the liquid level in the sewage expansion tank in real time, and a solenoid valve is arranged at the sewage outlet of the sewage expansion tank.

8. The wastewater recycling device of the coke oven gas waste heat utilization system according to claim 7 is characterized in that: The solenoid valve is connected to the PLC controller for control. When the second liquid level meter detects that the water level in the sewage expansion tank reaches a preset value, the PLC controller controls the solenoid valve to open and discharge sewage.

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