A demister flushing water graded recycling and reuse system

Abstract

This application discloses a graded recycling and reuse system for demister flushing water, relating to the field of wet desulfurization. The system includes an absorption tower, a secondary recovery system, and a primary recovery system. The absorption tower is equipped with multiple demister mechanisms. The secondary recovery system includes a clarifier connected to the upper demister for clarifying low-solids-content water. Two second branches are formed at the clarifier's outlet; one branch discharges gypsum sludge settled at the bottom of the clarifier, and the other branch connects to the upper demister. The primary recovery system includes a hydrocyclone connected to the outlet of the lower demister. Two first branches are formed at the hydrocyclone's outlet; one first branch connects to the absorption tower to transport high-solids-content water, and the other first branch connects to the clarifier and merges with the rear end of the secondary recovery system. This application grades the effluent slurry from the upper and lower demisters, effectively improving clarification efficiency.

Description

Technical Field

[0001] This utility model relates to the field of wet desulfurization, specifically to a demister flushing water graded recycling and reuse system. Background Technology

[0002] In multi-stage demister systems for wet desulfurization, the demisting efficiency of a single-stage demister is generally between 85% and 95%, meaning that the vast majority of slurry droplets are captured in the next-stage demister. Therefore, the surface of the next-stage demister has the most gypsum deposits, the highest flushing frequency, and the highest solids content in the flushing water. Current demister flushing water collection and recovery systems combine the high-solids-content next-stage flushing water with the low-solids-content upper-stage flushing water for treatment. This results in low processing efficiency, large equipment size, high investment, and low economic benefits. Utility Model Content

[0003] This application provides a graded recycling and reuse system for demister flushing water, which can solve the technical problem in the existing technology of multi-stage demister systems for wet desulfurization where the commonly used demister flushing water collection and recycling system combines the lower-stage flushing water with high solids content and the upper-stage flushing water with low solids content for recycling and treatment, resulting in low treatment efficiency and low economic benefits.

[0004] This application provides a demister flushing water graded recycling and reuse system, including:

[0005] An absorption tower is provided with a multi-layer demister mechanism, which includes at least an upper demister and a lower demister arranged vertically.

[0006] A secondary recovery system includes a clarifier for connecting to the outlet of the upper demister to clarify the low-solids water flowing out of the upper demister, and two second branches formed at the outlet of the clarifier, one of which is used to discharge the gypsum sludge settled in the clarifier, and the other second branch is connected to the upper demister to transport the clarified water in the clarifier to the upper demister.

[0007] The primary recovery system includes a hydrocyclone connected to the outlet of the lower demister, with two first branches formed at the outlet of the hydrocyclone. One first branch is connected to the absorption tower to transport high-solids-content water formed in the hydrocyclone, and the other first branch is connected to the clarifier to transport low-solids-content water formed in the hydrocyclone. The rear end of the primary recovery system is merged with the rear end of the secondary recovery system.

[0008] In one embodiment, both the upper and lower demisters include a demister mechanism and a water collection mechanism. The inlet of the primary recovery system is connected to the water collection mechanism of the lower demister, and the inlet of the secondary recovery system is connected to the water collection mechanism of the upper demister.

[0009] In one embodiment, control valves are provided between the primary recovery system and the lower demister, and between the secondary recovery system and the upper demister.

[0010] In one embodiment, the primary recovery system further includes a buffer tank located between the outlet of the lower demister and the cyclone separator.

[0011] In one embodiment, the buffer tank is equipped with a stirrer, and the stirring end of the stirrer is located inside the buffer tank.

[0012] In one embodiment, a buffer pump is also provided between the buffer tank and the cyclone separator.

[0013] In one embodiment, the secondary recovery system further includes a buffer structure located between the outlet of the upper demister and the clarifier.

[0014] In one embodiment, a sludge discharge pump is provided at the second branch outlet end for discharging the gypsum sludge that has settled at the bottom of the clarifier.

[0015] In one embodiment, the clarifier is provided with a sludge scraping mechanism at the bottom for conveying deposited gypsum to the sludge discharge pump.

[0016] In one embodiment, a clear water tank is provided on the second branch of the upper demister for conveying clarified water from the clarifier to the upper demister. A clear water pump is provided at the outlet of the clear water tank, and the outlet of the clear water pump is connected to the inlet of the upper demister.

[0017] The beneficial effects of the technical solutions provided in this application include:

[0018] This application, by setting up a primary and secondary recovery system that can operate independently, can classify and treat slurries with different solid contents flowing out of multi-level demisters. First, the solid content of the slurry from the lower-level demister is reduced, and then it is mixed with the slurry with a lower solid content from the upper-level demister. This can improve clarification efficiency, reduce the amount of water to be added to the wet desulfurization system, reduce the load on the clarifier, and lower the specifications of the clarification equipment, resulting in higher economic benefits. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1A schematic diagram of a demister flushing water graded recycling and reuse system provided in an embodiment of this application;

[0021] Figure 2 A schematic diagram of a primary recycling system in a graded recycling and reuse system for demister flushing water provided in this application embodiment;

[0022] Figure 3 This is a schematic diagram of a two-stage recycling system in a graded recycling and reuse system for demister flushing water provided in an embodiment of this application.

[0023] In the diagram: 1. Absorption tower; 2. Upper demister; 3. Lower demister; 4. Clarifier; 401. Second branch; 5. Cyclone separator; 501. First branch; 6. Buffer tank; 7. Agitator; 8. Buffer pump; 9. Sludge pump; 10. Clean water tank; 11. Clean water pump. Detailed Implementation

[0024] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0025] This application provides a demister flushing water graded recycling and reuse system, which can solve the technical problem in the prior art that the commonly used demister flushing water collection and recycling system in wet desulfurization multi-stage demister systems combines and recycles the lower-stage flushing water with high solids content and the upper-stage flushing water with low solids content for treatment, resulting in low treatment efficiency and low economic benefits.

[0026] The demister flushing water graded recycling and reuse system in this application includes an absorption tower 1 and a multi-layer demister mechanism located on the absorption tower 1. The multi-layer demister mechanism includes at least an upper demister 2 and a lower demister 3 arranged vertically, that is, the multi-layer demister mechanism includes multiple demister levels, but at least two levels, and any two of them are arranged vertically to connect to two recovery systems respectively. The upper demister 2 is connected to the secondary recovery system, and the lower demister 3 is connected to the primary recovery system. The slurry effluent from the upper demister 2 has a low solids content, so the secondary recovery system directly clarifies the slurry effluent from the upper demister 2. The slurry effluent from the lower demister 3 has a high solids content, so the front end of the primary recovery system performs initial solid-liquid separation on the slurry effluent from the lower demister 3 to reduce the solids content of the slurry. Then, the back end of the primary recovery system is merged with the secondary recovery system, and the slurry that has completed the initial solid-liquid separation can be transferred to the secondary recovery system for clarification treatment.

[0027] The upper demister 2 and the lower demister 3 both include a demister mechanism and a water collection mechanism. The demister mechanism is a commonly used demister in desulfurization systems. The water collection mechanism can be an independently added water collection device or a water collection structure built into the demister mechanism itself. This application does not impose any restrictions. The two water collection structures are additionally provided with inlet and outlet branches to connect to the primary recovery system and the secondary recovery system, respectively.

[0028] Further details can be found here. Figure 1 The secondary recovery system includes a clarifier 4 connected to the outlet of the upper demister 2 for clarifying the slurry flowing out of the upper demister 2. In one possible embodiment, the clarifier 4 preferably employs gravity clarification, separating the liquid and gypsum in the flowing slurry to form gypsum sludge and clear water. Two second branches 401 are formed at the outlet of the clarifier 4, one of which is used to discharge the gypsum sludge that has settled at the bottom of the clarifier 4, and the other second branch 401 is connected to the upper demister 2 to transport the clarified clear water from the clarifier 4 to the upper demister 2. Of course, the clarified clear water can also be disposed of in multiple ways as needed, such as for demister flushing, or connected to the outside for use as pulping water, slurry pipeline flushing water, or desulfurization wastewater, etc., and is not necessarily limited to being connected to the upper demister 2.

[0029] Further details can be found here. Figure 1 The primary recovery system includes a hydrocyclone 5 connected to the outlet of the lower demister 3. The hydrocyclone 5 is a device that uses centrifugal force to separate components of different densities in a mixture. Through the hydrocyclone 5, the slurry flowing out of the lower demister 3 can be divided into high solids content water and low solids content water. Two first branches 501 are formed at the outlet of the hydrocyclone 5. One of the first branches 501 is connected to the absorption tower 1 to transport the high solids content water formed in the hydrocyclone 5. Of course, the high solids content water here can also be sent to other places such as the pit as needed. The other first branch 501 is connected to the clarifier 4 and merged with the back end of the secondary recovery system to transport the low solids content water formed in the hydrocyclone 5 to the secondary recovery system. The low solids content water and the slurry flowing out of the upper demister 2 are clarified together by the processing mechanism of the secondary recovery system.

[0030] Furthermore, control valves are provided between the primary recovery system and the lower demister 3, and between the secondary recovery system and the upper demister 2. These control valves can operate independently and automatically switch to enable independent operation or shutdown of the two recovery systems.

[0031] Furthermore, Figure 2 This application provides a schematic diagram of a primary recycling system in a graded recycling and reuse system for demister flushing water, as shown in the embodiments of this application. Figure 2As shown, the primary recovery system also includes a buffer tank 6, located between the outlet of the lower demister 3 and the hydrocyclone 5. A buffer pump 8 is also installed between the buffer tank 6 and the hydrocyclone 5. The slurry exiting the lower demister 3 first enters the buffer tank 6 for buffering, and then is transported to the hydrocyclone 5 by the buffer pump 8 for preliminary separation to ensure the stable operation of the hydrocyclone 5. An agitator 7 is installed on the buffer tank 6, and the agitator blades of the agitator 7 are located inside the buffer tank 6. The agitator 7 can prevent gypsum deposition in the slurry inside the buffer tank 6.

[0032] Furthermore, Figure 3 This application provides a schematic diagram of a two-stage recycling system in a demister flushing water graded recycling and reuse system, as shown in the embodiments of this application. Figure 3 As shown, the secondary recovery system also includes a buffer structure, which is located between the outlet of the upper demister 2 and the clarifier 4. The buffer structure can be similar to the primary recovery system, with a buffer tank 6 and a buffer pump 8. The slurry from the upper demister 2 is smoothly transported to the clarifier 4 via the buffer pump 8 to reduce the impact of slurry impact on the clarification process and ensure the clarification effect of the clarifier 4.

[0033] Furthermore, a sludge discharge pump 9 is provided at the outlet end of the second branch 401 used to discharge the gypsum sludge settled at the bottom of the clarifier 4. A sludge scraping mechanism is provided at the bottom of the clarifier 4 to transport the deposited gypsum to the sludge discharge pump 9. In one possible embodiment, the sludge scraping mechanism is set on the inner wall of the bottom of the clarifier 4 in conjunction with a sensor. When the deposited gypsum in the clarifier 4 reaches a certain height / thickness, the sludge scraping mechanism automatically starts scraping to facilitate the transport of the deposited gypsum to the sludge discharge pump 9. As an optional embodiment, the sludge discharge pump 9 discharges to the outside desulfurized gypsum dewatering machine.

[0034] Furthermore, a clear water tank 10 is provided on the second branch 401 of the upper demister 2 for conveying the clarified water in the clarifier 4 to the upper demister 2. A clear water pump 11 is provided at the outlet end of the clear water tank 10. The clear water tank 10 is connected to the upper side wall of the clarifier 4. In one possible embodiment, the clear water pump 11 can also be used in conjunction with a sensor. When the sensor senses that the clear water level in the clear water tank 10 has reached a certain height, the clear water pump 11 is activated to extract the clear water from the clear water tank 10. In one possible embodiment, the outlet end of the second branch 401 can be connected to the inlet end of the upper demister 2, or it can be connected to the outside for use as pulping water, slurry pipeline flushing water, desulfurization wastewater discharge, etc.

[0035] The mechanism of the graded recycling and reuse system for demister flushing water in this application is as follows: The primary and secondary recycling systems can be operated simultaneously or separately, depending on the demand for the amount and quality of recycled water. Taking the simultaneous operation of the upper demister 2 and the lower demister 3 in a multi-layer demister mechanism as an example, the slurry effluent from the lower demister 3 in the primary recycling system undergoes preliminary treatment by the hydrocyclone 5 to form high-solids-content water and low-solids-content water. The high-solids-content water is sent back to the absorption tower 1 for absorption and reaction alone, while the low-solids-content water flows through the buffer tank 6 and the buffer pump 8 in sequence to the clarifier 4 for clarification, forming gypsum sludge and clear water. The gypsum sludge is discharged to the external desulfurization gypsum dewatering machine via the sludge discharge pump 9, and the clear water is discharged to the inlet of the upper demister 2 via the clear water pump 11. It can also be connected to the outside for use as pulping water, slurry pipeline flushing water, and desulfurization wastewater discharge. Since the slurry effluent from the upper demister 2 in the secondary recovery system has a low solids content, it can directly enter the clarifier 4. At this time, the low solids content water separated from the slurry effluent from the upper demister 2 and the slurry effluent from the lower demister 3 has the same solids content, and they can be clarified together in the clarifier 4. The clarification process is the same as the above process, and will not be described in detail here.

[0036] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0037] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0038] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A demister flushing water graded recycling and reuse system, characterized in that, include: An absorption tower (1) is provided with a multi-layer demister mechanism, which includes at least an upper demister (2) and a lower demister (3) arranged vertically. A secondary recovery system includes a clarifier (4) for connecting to the outlet of the upper demister (2) to clarify the low solid content water flowing out of the upper demister (2). Two second branches (401) are formed at the outlet of the clarifier (4), one of which is used to discharge the gypsum sludge settled in the clarifier (4), and the other second branch (401) is connected to the upper demister (2) to transport the clarified water in the clarifier (4) to the upper demister (2). The primary recovery system includes a hydrocyclone (5) connected to the outlet end of the lower demister (3), forming two first branches (501) at the outlet end of the hydrocyclone (5), one of which is connected to the absorption tower (1) to transport high solids content water formed in the hydrocyclone (5), and the other first branch (501) is connected to the clarifier (4) to transport low solids content water formed in the hydrocyclone (5), and the rear end of the primary recovery system is merged with the rear end of the secondary recovery system.

2. The demister flushing water graded recycling and reuse system as described in claim 1, characterized in that: The upper demister (2) and the lower demister (3) both include a demister mechanism and a water collection mechanism. The inlet of the primary recovery system is connected to the water collection mechanism of the lower demister (3), and the inlet of the secondary recovery system is connected to the water collection mechanism of the upper demister (2).

3. A demister flushing water graded recycling and reuse system as described in claim 2, characterized in that: Control valves are provided between the primary recovery system and the lower demister (3) and between the secondary recovery system and the upper demister (2).

4. A demister flushing water graded recycling and reuse system as described in claim 1, characterized in that: The primary recovery system also includes a buffer tank (6), which is located between the outlet of the lower demister (3) and the cyclone separator (5).

5. A demister flushing water graded recycling and reuse system as described in claim 4, characterized in that: The buffer tank (6) is equipped with a stirrer (7), and the stirring end of the stirrer (7) is located inside the buffer tank (6).

6. A demister flushing water graded recycling and reuse system as described in claim 5, characterized in that: A buffer pump (8) is also provided between the buffer tank (6) and the cyclone separator (5).

7. A demister flushing water graded recycling and reuse system as described in claim 1, characterized in that: The secondary recovery system also includes a buffer structure located between the outlet of the upper demister (2) and the clarifier (4).

8. A demister flushing water graded recycling and reuse system as described in claim 1, characterized in that: A sludge pump (9) is installed at the outlet end of the second branch (401) used to discharge the gypsum sludge that has settled in the clarifier (4).

9. A demister flushing water graded recycling and reuse system as described in claim 8, characterized in that: The bottom of the clarifier (4) is provided with a sludge scraping mechanism for conveying deposited gypsum to the sludge pump (9).

10. A demister flushing water graded recycling and reuse system as described in claim 9, characterized in that: A clear water tank (10) is provided on the second branch (401) of the upper demister (2) for conveying the clarified water in the clarifier (4). A clear water pump (11) is provided at the outlet end of the clear water tank (10), and the outlet end of the clear water pump (11) is connected to the inlet end of the upper demister (2).

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