Absorption tower slurry emergency storage and cyclic utilization system

Abstract

The invention relates to an emergency storage and cyclic utilization system for slurry of an absorption tower. The system comprises a first accident slurry storage device, a second accident slurry storage device, a first drainage pit group, a second drainage pit group, an absorption tower group, a middle storage area gypsum slurry group and a wastewater recycling device, liquid inlets of the first accident slurry storage device and the second accident slurry storage device are respectively communicated with the absorption tower group; a liquid outlet of the first accident slurry storage device is respectively communicated with the second drainage pit group, the absorption tower group, the middle storage area gypsum slurry group and the wastewater recycling device; and a liquid outlet of the second accident slurry storage device is communicated with the absorption tower group, the middle storage area gypsum slurry group and the wastewater recycling device. Compared with the prior art, the method has the advantages of improving the overall operation efficiency and environmental protection performance of the system and the like.

Description

Technical Field

[0001] The present invention relates to the field of chemical production, and in particular to an absorption tower slurry emergency storage and recycling system. Background Art

[0002] The existing absorption tower slurry storage and recycling system often has insufficient slurry processing capacity when responding to emergencies, resulting in limited slurry discharge from the absorption tower. The slurry may flow into the rainwater well and pollute the environment, or settle and accumulate in the absorption tower, causing the accident to escalate.

[0003] Although the systems disclosed in reference patents CN210584457U and CN109224827A perform well in reducing pollutants emitted during the electrolytic aluminum production process, their system flexibility and emergency handling capabilities still need to be improved in terms of emergency storage and recycling of absorption tower slurry, especially when responding to emergencies such as absorption tower wall damage and complete mixer shutdown.

[0004] Although these two patents can effectively reduce pollutant emissions, there is still a lack of effective solutions in emergency situations, such as the rapid and safe treatment of slurry in the absorption tower, which limits their application in environmental emergency treatment, resulting in low overall operating efficiency and less than ideal environmental performance. Summary of the Invention

[0005] The purpose of the present invention is to provide an emergency slurry tank system in order to overcome the defects of the above-mentioned prior art.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] According to one aspect of the present invention, an absorption tower slurry emergency storage and recycling system is provided, which includes a first emergency slurry storage device 1, a second emergency slurry storage device 2, a first drainage pit group 3, a second drainage pit group 4, an absorption tower group, a gypsum slurry group in the intermediate storage area, and a wastewater reuse device 5;

[0008] The liquid inlets of the first accident slurry storage device 1 and the second accident slurry storage device 2 are respectively connected to the absorption tower group; the liquid outlet of the first accident slurry storage device 1 is respectively connected to the second drainage pit group 4, the absorption tower group, the middle storage area gypsum slurry group and the wastewater reuse device 5; the liquid outlet of the second accident slurry storage device 2 is connected to the absorption tower group, the middle storage area gypsum slurry group and the wastewater reuse device 5.

[0009] As a preferred technical solution, the second emergency slurry storage device 2 includes a second emergency slurry tank 22 , a stirring mechanism 21 and a return pump group 23 .

[0010] As a preferred technical solution, the second emergency slurry tank 22 adopts carbon steel structure, glass flake anti-corrosion, with specifications of Φ13m×15.5m and effective volume of 2000m 3 .

[0011] As a preferred technical solution, a manhole door is provided on the top of the second emergency slurry tank 22.

[0012] As a preferred technical solution, the stirring mechanism 21 is 4 side-entry stirrers, and the 4 side-entry stirrers are opened from the side of the second emergency slurry tank 22 and are evenly arranged in the second emergency slurry tank 22 at equal intervals.

[0013] As a preferred technical solution, the return pump group 23 is arranged on the output path of the second accident slurry tank 22, and a ditch is also connected between the return pump group 23 and the second accident slurry tank 22; the return pump group 23 includes at least a first accident slurry return pump and a second accident slurry return pump, wherein the second accident slurry return pump serves as a backup.

[0014] As a preferred technical solution, the input of the first drainage pit group 3 includes the pH tank sampling tube, chimney condensate, absorption tower overflow and absorption tower area drainage, and the input end of each drainage pit in the first drainage pit group 3 is connected to the process water pump through the drainage pit pump; the output end is connected to the absorption tower group through the drainage pit pump;

[0015] The input of the second drainage pit includes drainage from the area of ​​the first accident slurry storage device 1, and the input end of the first drainage pit is connected to the process water pump through the drainage pit pump; the output end is connected to the absorption tower group through the drainage pit pump.

[0016] As a preferred technical solution, the second drainage pit is equipped with a stirring mechanism 21 and a pit pump. The stirring mechanism 21 is a top-entry stirrer 41 and the pit pump is a vertical submersible pump 42.

[0017] As an optimal technical solution, a number of emergency slurry pumps and electric valves are provided between the second emergency slurry storage device 2 and the gypsum slurry group in the middle storage area and the first emergency slurry storage device 1, so as to realize the slurry transportation of the second emergency slurry storage device 2 to the gypsum slurry tank in the middle storage area and the first emergency slurry storage device 1, and the slurry transportation direction of the slurry of the second emergency slurry storage device 2 is switched by the electric valve.

[0018] As a preferred technical solution, the wastewater reuse device 5 includes a wastewater reuse tank; the wastewater reuse tank is provided with a wastewater utilization tank level selector, and its input end is connected to the first accident slurry storage device 1 and the second accident slurry storage device 2 through the wastewater buffer tank; its output end is connected to the wastewater reuse point through the wastewater reuse pump; the output point is also provided with a wastewater reuse pump outlet pressure gauge and a wastewater reuse pump return gate.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. In the present invention, dual emergency slurry storage devices (a first emergency slurry storage device and a second emergency slurry storage device) are connected to multiple circuits to establish a primary and standby redundant system, enabling multi-directional flow of absorber slurry between emergency storage, recycling, and standard-compliant treatment. This avoids interruptions in slurry treatment caused by failure of a single storage device, significantly improving system reliability and emergency response capabilities. This increases the storage and recycling capacity of emergency slurry, ensuring that in the event of an absorber failure, the slurry can be quickly and safely transferred to the emergency slurry storage device, avoiding environmental contamination by the slurry while ensuring the recycling of the slurry, thereby improving the overall operating efficiency and environmental performance of the system.

[0021] 2. In the present invention, the second emergency slurry tank adopts carbon steel structure and glass flake anti-corrosion design, which can withstand the strong corrosiveness of desulfurization slurry and extend the life of the equipment; large capacity design (Φ13m×15.5m, 2000m 3 ) to meet the rapid slurry storage needs in case of sudden accidents of large units.

[0022] 3. In the present invention, the four side-entry agitators in the second emergency slurry storage device are arranged at equal intervals along the side of the box to form an all-round three-dimensional stirring flow field, eliminating the dead corner deposition of the stored slurry; the high stirring rate can effectively prevent the gypsum crystals from settling and hardening, providing stable conditions for subsequent pumping and reuse.

[0023] 4. In the present invention, by setting up a return pump group with one in use and one in backup, it automatically switches when the main pump fails, ensuring uninterrupted slurry transportation and improving the system's ability to resist equipment failure; through the trench between the pump group and the box body, the slurry leaked from the pump body seal is collected in real time to avoid contaminating the ground and corroding the equipment foundation, so that the system meets environmental protection and safe operation and maintenance requirements.

[0024] 5. In the present invention, the first drainage pit group centrally processes wastewater from multiple sources, such as residual liquid from pH tank sampling and chimney condensate. The drainage pit pump is connected to the process water pump, allowing qualified wastewater to be reused for absorption tower replenishment. The second drainage pit collects drainage from the first accident slurry storage device area, avoiding the increased processing complexity caused by the mixing of wastewater from different areas and achieving zoned collection and targeted treatment. In the second drainage pit, a top-entry agitator vertically stirs the slurry in the drainage pit to prevent sediment and gypsum particles from clogging the pump body and ensuring stable operation of the pit pump. The submerged installation design of the vertical submersible pump adapts to the deep liquid level conditions in the drainage pit, improving slurry suction efficiency and reducing the risk of pump idling.

[0025] 6. The wastewater reuse device of the present invention is provided with a liquid level selector to monitor the liquid level of the wastewater reuse tank in real time, and to start and stop the wastewater reuse pump in conjunction to avoid overflow or idling, thereby realizing automatic control; a pressure gauge and a return gate are provided, and output end pressure monitoring and overpressure backflow protection are provided to prevent the wastewater delivery pipeline from rupture due to sudden pressure changes, thereby ensuring the safety of the reuse process. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic structural diagram of an absorption tower slurry emergency storage and recycling system in the present invention;

[0027] Figure 2 This is a schematic structural diagram of the second emergency slurry storage device and the second drainage pit group in the present invention;

[0028] In the figure, 1 is the first emergency slurry storage device; 2 is the second emergency slurry storage device; 21 is the stirring mechanism; 22 is the second emergency slurry tank; 23 is the return pump group; 3 is the first drainage pit group; 4 is the second drainage pit group; 41 is the top-entry stirrer; 42 is the vertical submersible pump; 5 is the wastewater reuse device; DETAILED DESCRIPTION

[0029] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0030] Example

[0031] In this embodiment, an absorption tower slurry emergency storage and recycling system is used. Figure 1 As shown, it includes a first accident slurry storage device 1, a second accident slurry storage device 2, a first drainage pit group 3, a second drainage pit group 4, an absorption tower group, a middle storage area gypsum slurry group and a wastewater recycling device 5;

[0032] The liquid inlets of the first accident slurry storage device 1 and the second accident slurry storage device 2 are respectively connected to the absorption tower group; the liquid outlet of the first accident slurry storage device 1 is respectively connected to the second drainage pit group 4, the absorption tower group, the middle storage area gypsum slurry group and the wastewater reuse device 5; the liquid outlet of the second accident slurry storage device 2 is connected to the absorption tower group, the middle storage area gypsum slurry group and the wastewater reuse device 5.

[0033] The structure of the second emergency slurry storage device 2 is as follows Figure 2 As shown, it includes a second emergency slurry tank 22, a stirring mechanism 21 and a return pump group 23.

[0034] The second emergency slurry tank 22 is made of carbon steel structure and glass flake for corrosion protection. Its specifications are Φ13m×15.5m and its effective volume is 2000m 3 .

[0035] A manhole door is provided on the top of the second emergency slurry tank 22.

[0036] The stirring mechanism 21 is composed of four side-entry stirrers. The four side-entry stirrers are opened from the side of the second emergency slurry tank 22 and are evenly arranged in the second emergency slurry tank 22 at equal intervals.

[0037] The return pump group 23 is arranged on the output passage of the second accident slurry tank 22, and a ditch is also connected between the return pump group 23 and the second accident slurry tank 22; the return pump group 23 includes at least a first accident slurry return pump and a second accident slurry return pump, wherein the second accident slurry return pump serves as a backup.

[0038] The input of the first drainage pit group 3 includes the pH tank sampling tube, chimney condensate, absorption tower overflow and absorption tower area drainage, and the input end of each drainage pit in the first drainage pit group 3 is connected to the process water pump through the drainage pit pump; the output end is connected to the absorption tower group through the drainage pit pump;

[0039] The second drainage pit structure is as follows Figure 2 As shown, its input includes drainage from the first accident slurry storage device 1 area, and the input end of the first drainage pit is connected to the process water pump through the drainage pit pump; the output end is connected to the absorption tower group through the drainage pit pump.

[0040] The second drainage pit is equipped with a stirring mechanism 21 and a pit pump. The stirring mechanism 21 is a top-entry stirrer 41 and the pit pump is a vertical submersible pump 42.

[0041] Several emergency slurry pumps and electric valves are provided between the second emergency slurry storage device 2 and the gypsum slurry group in the middle storage area and the first emergency slurry storage device 1, so as to realize the transportation of the slurry of the second emergency slurry storage device 2 to the gypsum slurry tank in the middle storage area and the first emergency slurry storage device 1. The slurry transportation direction of the slurry of the second emergency slurry storage device 2 is switched by the electric valve.

[0042] The wastewater reuse device 5 includes a wastewater reuse tank; the wastewater reuse tank is provided with a wastewater utilization tank level selector, and its input end is connected to the first accident slurry storage device 1 and the second accident slurry storage device 2 through the wastewater buffer tank; its output end is connected to the wastewater reuse point through the wastewater reuse pump; the output point is also provided with a wastewater reuse pump outlet pressure gauge and a wastewater reuse pump return gate.

[0043] This example uses a 300MW coal-fired unit wet desulfurization system as an application scenario. An absorber slurry emergency storage and recycling system is configured to solve the problem of efficient management of desulfurization slurry during emergency response, maintenance, and resource recovery. The specific composition and operation process of the system are as follows:

[0044] 1. System core components and parameters

[0045] Main structure

[0046] The system includes the first accident slurry storage device 1 (the original system, as a backup), the second accident slurry storage device 2 (a newly added core device), an absorption tower group (4 desulfurization absorption towers), a middle storage area gypsum slurry group (2 gypsum slurry tanks), a first drainage pit group 3 (3), a second drainage pit (1) and a wastewater reuse device 5.

[0047] Second emergency slurry storage device 2 (newly added key equipment)

[0048] Box design: Carbon steel structure, inner wall coated with glass flake anti-corrosion layer, specification is Φ13m×15.5m, effective volume is 2000m 3 , which can accommodate 80% of the slurry volume of a single absorption tower; there are two manhole doors (800mm in diameter) on the top for internal inspection and anti-corrosion layer maintenance.

[0049] Mixing mechanism 21: equipped with 4 side-entry agitators, extending from the side opening of the box, arranged at equal intervals along the circumference (90° spacing), with a rotation speed of 30r / min, to ensure uniform mixing of the slurry and prevent gypsum crystals from settling and hardening.

[0050] Return pump group 23: The output channel is equipped with two horizontal centrifugal pumps (the first and second emergency slurry return pumps), with a flow rate of 200m 3 / h, lift 30m; the second emergency slurry return pump is a backup pump, connected in parallel with the main pump through a check valve; a trench is set between the pump group and the box body to collect slurry leaked from the pump body to avoid pollution.

[0051] 2. Drainage pit group function and linkage

[0052] First drainage pit group 3

[0053] Receiving scope: pH tank sampling residual liquid, chimney condensate, absorption tower overflow slurry and absorption tower area ground flushing water.

[0054] Operation logic: Each drainage pit is connected to the process water pump through a horizontal drainage pit pump to replenish process water; at the same time, the collected qualified slurry is returned to the absorption tower group through the same water pump to realize water resource circulation.

[0055] Second drainage pit

[0056] Exclusive function: only collects ground drainage and equipment leakage slurry in the first accident slurry storage device 1 area.

[0057] Ancillary equipment: a top-entry agitator 41 is provided to prevent the slurry from settling; a vertical submersible pump 42 is provided to return the treated slurry to the absorption tower, or to temporarily store the slurry for further treatment when the slurry exceeds the standard.

[0058] 3. Slurry transportation and switching control

[0059] Multi-directional conveying path: The second emergency slurry storage device 2 is connected to the gypsum slurry group in the middle storage area and the first emergency slurry storage device 1 through three emergency slurry pumps (two in use and one in reserve) and ten sets of electric valves. The conveying direction can be switched through PLC control:

[0060] Normal working condition: The qualified slurry (solid content 15-20%) from the second emergency slurry storage device 2 is transported to the gypsum slurry tank in the intermediate storage area for processing by the gypsum dehydration system;

[0061] Emergency working condition: By switching the electric valve, the slurry is transported in reverse to the first emergency slurry storage device 1.

[0062] 4. Wastewater reuse device 5

[0063] Composition: includes wastewater reuse tank, wastewater buffer tank, wastewater reuse pump and supporting instruments; the wastewater reuse tank is equipped with a liquid level selector to monitor the liquid level in real time and start and stop the pump group in conjunction.

[0064] Operation process: The supernatant discharged from the first and second accident slurry storage devices 2 first enters the wastewater buffer tank and then is transported to the wastewater reuse tank; it is pumped to the limestone slurry preparation link of the desulfurization system through the wastewater reuse pump, and a pressure gauge and a return gate are installed at the output end to prevent slurry backflow in case of overpressure.

[0065] 5. Typical operating conditions example

[0066] Scenario: The absorption tower needs urgent repair due to a stirrer failure

[0067] Emergency storage: Open the electric valve from the absorption tower to the second emergency slurry storage device 2 through PLC control, start the absorption tower slurry pump, and drain 1500m3 of slurry from the tower. 3 The slurry was transferred to the second emergency slurry storage device 2 within 2 hours; during this period, the four side-entry agitators continued to operate to ensure that the slurry was uniform and did not settle.

[0068] Drainage treatment: During the maintenance period, the flushing water in the second accident slurry storage device 2 area flows into the second drainage pit through the ditch. The top-entry agitator 41 stirs to prevent sedimentation, and the vertical submersible pump 42 returns the qualified wastewater to the absorption tower group for reuse.

[0069] Recovery after maintenance: After the maintenance of the absorption tower is completed, start the second accident slurry return pump and pump the stored slurry at 50m 3 / h flow rate is returned to the absorption tower; at the same time, the excess slurry is switched to the gypsum slurry tank in the intermediate storage area through the emergency slurry pump and processed into gypsum products through the dehydration system.

[0070] Wastewater reuse: After the slurry is returned, the supernatant at the bottom of the second accident slurry storage device 2 is pre-treated in the wastewater buffer tank and then pumped to the limestone slurry making system by the wastewater reuse pump. The reuse rate reaches 85%, reducing fresh water consumption.

[0071] VI. Implementation Effect

[0072] This system achieves the following effects through "double emergency slurry storage device redundancy design", "multi-path slurry switching", and "full-process reuse of drainage and wastewater":

[0073] In the event of an accident, the slurry transfer time is shortened to 1 / 3 of that of the traditional system, avoiding slurry leakage and pollution in the absorption tower;

[0074] The anti-corrosion and stirring design of the second emergency slurry storage device 2 extends the slurry storage period to 72 hours without caking;

[0075] The drainage and wastewater reuse rate has increased to 90%, reducing industrial water consumption by approximately 12,000 tons annually and increasing the gypsum recovery rate by 5%.

[0076] This example fully demonstrates the advantages of the system in emergency response, resource circulation, and stability, and is suitable for refined slurry management in desulfurization systems of large thermal power plants.

[0077] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and such modifications or substitutions are intended to be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. An absorption tower slurry emergency storage and recycling system, characterized in that: The system comprises a first accident slurry storage device (1), a second accident slurry storage device (2), a first drainage pit group (3), a second drainage pit group (4), an absorption tower group, a middle storage area gypsum slurry group and a wastewater recycling device (5); The liquid inlets of the first accident slurry storage device (1) and the second accident slurry storage device (2) are respectively connected to the absorption tower group; the liquid outlet of the first accident slurry storage device (1) is respectively connected to the second drainage pit group (4), the absorption tower group, the middle storage area gypsum slurry group and the wastewater reuse device (5); the liquid outlet of the second accident slurry storage device (2) is connected to the absorption tower group, the middle storage area gypsum slurry group and the wastewater reuse device (5).

2. The absorption tower slurry emergency storage and recycling system according to claim 1, characterized in that: The second emergency slurry storage device (2) comprises a second emergency slurry tank (22), a stirring mechanism (21) and a return pump group (23).

3. The absorption tower slurry emergency storage and recycling system according to claim 2, characterized in that: The second emergency slurry tank (22) is made of carbon steel structure and glass flake anti-corrosion, with a specification of Φ13m×15.5m and an effective volume of 2000m 3 .

4. The absorption tower slurry emergency storage and recycling system according to claim 3, characterized in that: The top of the second emergency slurry tank (22) is provided with a manhole door.

5. The absorption tower slurry emergency storage and recycling system according to claim 2, characterized in that: The stirring mechanism (21) is composed of four side-entry stirrers, which are opened from the side of the second emergency slurry tank (22) and are evenly arranged in the second emergency slurry tank (22) at equal intervals.

6. The absorption tower slurry emergency storage and recycling system according to claim 2, characterized in that: The return pump group (23) is arranged on the output path of the second accident slurry tank (22), and a ditch is also connected between the return pump group (23) and the second accident slurry tank (22); the return pump group (23) includes at least a first accident slurry return pump and a second accident slurry return pump, wherein the second accident slurry return pump serves as a backup.

7. The absorption tower slurry emergency storage and recycling system according to claim 1, characterized in that: The input of the first drainage pit group (3) includes pH tank sampling tube, chimney condensate, absorption tower overflow and absorption tower area drainage, and the input end of each drainage pit in the first drainage pit group (3) is connected to the process water pump through the drainage pit pump; the output end is connected to the absorption tower group through the drainage pit pump; The second drainage pit input includes drainage from the first accident slurry storage device (1), and the input end of the first drainage pit is connected to the process water pump via a drainage pit pump; the output end is connected to the absorption tower group via the drainage pit pump.

8. The absorption tower slurry emergency storage and recycling system according to claim 7, characterized in that: The second drainage pit is equipped with a stirring mechanism (21) and a pit pump, wherein the stirring mechanism (21) is a top-entry stirrer (41) and the pit pump is a vertical submersible pump (42).

9. The absorption tower slurry emergency storage and recycling system according to claim 1, characterized in that: A plurality of emergency slurry pumps and electric valves are provided between the second emergency slurry storage device (2), the middle storage area gypsum slurry group and the first emergency slurry storage device (1), so as to realize the slurry of the second emergency slurry storage device (2) being transported to the middle storage area gypsum slurry tank and the first emergency slurry storage device (1), and the slurry transport direction of the slurry of the second emergency slurry storage device (2) is switched by the electric valve.

10. The absorption tower slurry emergency storage and recycling system according to claim 1, characterized in that: The wastewater recycling device (5) includes a wastewater recycling tank; the wastewater recycling tank is provided with a wastewater utilization tank level selector, the input end of which is connected to the first accident slurry storage device (1) and the second accident slurry storage device (2) via the wastewater buffer tank; the output end of which is connected to the wastewater recycling point via the wastewater recycling pump; the output point is also provided with a wastewater recycling pump outlet pressure gauge and a wastewater recycling pump return gate.

Images