A slurry pretreatment recovery device

Abstract

The application discloses a slurry pretreatment recovery device, which comprises a cooling assembly, an initial filtration treatment assembly and a later filtration treatment assembly; the water inlet and outlet of the cooling assembly are connected with an initial slurry collecting tank; the initial filtration treatment assembly is used for filtering and separating the supernatant of the initial slurry collecting tank, wherein the filtrate is collected in a filtrate collecting tank, and the residue is collected in a later slurry collecting tank; the initial filtration treatment assembly is used for filtering and separating the slurry of the initial slurry collecting tank, wherein the filtrate is collected in the initial slurry collecting tank, and the residue is collected in the later slurry collecting tank; the later filtration treatment assembly is used for filtering and separating the liquid of the later slurry collecting tank, wherein the filtrate is collected in the initial slurry collecting tank, and the residue is collected in a slurry preparation tank. The electromagnetic valve and the flowmeter are used to replace the original manual valve, the on-off of the electromagnetic valve is controlled according to the liquid demand of the reaction kettle, and the safety and accuracy of the control are improved.

Description

Technical Field

[0001] This invention relates to the field of slurry treatment technology, and more specifically to a slurry pretreatment and recovery device. Background Technology

[0002] During the ADC production process, wastewater is generated, which is a suspended slurry containing COD and ammonia nitrogen. Existing slurry pretreatment systems are mostly divided into a pre-slurry filtration treatment section and a post-slurry filtration treatment section. The filtrate discharged from the reactor first enters the pre-slurry collection tank after being filtered in the post-slurry filtration treatment section. The filtrate in the pre-slurry collection tank is cooled by circulating evaporation through a cooling tower, and gradually cools and crystallizes at the bottom of the pre-slurry collection tank to form the pre-slurry. The pre-slurry is then filtered in the pre-slurry filtration treatment section and enters the filtrate collection tank to complete the slurry pretreatment and recovery.

[0003] like Figure 1 The diagram shows an existing slurry pretreatment and recovery device. The mixture of filtrate and filter residue from the reactor is separated into filtrate by a vacuum belt filter. The filtrate enters the initial slurry collection tank. A cooling tower draws filtrate from the initial slurry collection tank for cooling. The filtrate crystallizes in the initial slurry collection tank after being cooled by the cooling tower. A slurry pump draws the filtrate from the initial slurry collection tank to the initial slurry filtration tank. Since the initial slurry collection tank contains a mixture of filtrate and crystals, the filtrate drawn to the initial slurry filtration tank needs to be washed again. The filtrate is washed and filtered in the initial slurry filtration tank with hot water heated by steam. The washed filtrate enters the filtrate collection tank, and the filter residue is washed with hot water and enters the later slurry collection tank, completing the slurry pretreatment and recovery process.

[0004] The existing equipment has the following drawbacks: 1. Washing the filtrate requires a large amount of hot water, resulting in high water and steam consumption; 2. The addition of hot water significantly increases the total amount of filtrate produced, leading to a substantial increase in the water consumption and treatment costs required to treat the waste filtrate to meet discharge standards; 3. The filtrate filtered through the initial slurry filtration tank has a high residue content, and direct entry into the filtrate collection tank will cause the loss of effective components, resulting in high COD and ammonia nitrogen content; 4. There is a risk of tank overflow; 5. Pipelines are prone to blockage; 6. The large number of pipeline valves leads to high labor intensity for operators. Summary of the Invention

[0005] This invention provides a slurry pretreatment and recovery device to solve the technical problems in the prior art, such as high steam and water consumption, increased total filtrate volume, high waste filtrate treatment costs, easy loss of effective components, risk of storage tank overflow, easy pipe blockage, and numerous pipe valves.

[0006] This invention provides a slurry pretreatment and recovery device, comprising: a cooling component, an initial filtration component, and a subsequent filtration component; the inlet and outlet of the cooling component are both connected to an initial slurry collection tank; the initial filtration component filters and separates the upper clear liquid in the initial slurry collection tank, wherein the filtrate is recovered to the filtrate collection tank and the filter residue is recovered to the subsequent slurry collection tank; the initial filtration component filters and separates the lower slurry in the initial slurry collection tank, wherein the filtrate is recovered to the initial slurry collection tank and the filter residue is recovered to the subsequent slurry collection tank; the subsequent filtration component filters and separates the liquid in the subsequent slurry collection tank, wherein the filtrate is recovered to the initial slurry collection tank and the filter residue is recovered to the slurry preparation tank.

[0007] Furthermore, the initial filtration treatment component includes an impurity filter and an initial slurry filter tank; the inlet of the impurity filter is connected to the initial slurry collection tank, the slag discharge port is connected to the later slurry collection tank, and the liquid outlet is connected to the filtrate collection tank; the inlet of the initial slurry filter tank is connected to the initial slurry collection tank, the liquid outlet is connected to the initial slurry collection tank, and the slag discharge port is connected to the later slurry collection tank.

[0008] Furthermore, the inlet of the impurity filter is connected to the upper clear liquid layer of the initial slurry collection tank; the inlet of the initial slurry filter tank is connected to the lower slurry layer of the initial slurry collection tank.

[0009] Furthermore, the post-filtration treatment components include a reactor, a slurry separator, a slurry preparation tank, a solenoid valve, a flow meter, and a controller. The slurry inlet of the reactor is connected to the post-slurry collection tank, and the filtrate outlet is connected to the inlet of the slurry separator. The filtrate outlet of the slurry separator is connected to the initial slurry collection tank, and the slag outlet is connected to the slurry preparation tank. The solenoid valve and the flow meter are installed in the pipeline connecting the post-slurry collection tank to the slurry inlet of the reactor. The solenoid valve and the flow meter are connected to the controller, and the controller controls the on / off state of the solenoid valve based on the slurry demand of the reactor and the metering of the flow meter.

[0010] Furthermore, compressed air is introduced at the bend of the pipe connecting the later slurry collection tank to the slurry inlet of the reactor, and a solenoid valve is installed in the compressed air inlet pipe; the solenoid valve is connected to the controller, and the compressed air blowing state is controlled based on the controller's control signal.

[0011] Furthermore, the impurity filter is a microporous PE filter.

[0012] Furthermore, the sludge-liquid separator is a vacuum belt filter.

[0013] The beneficial effects of this invention are:

[0014] This invention addresses the filtration of wastewater generated during the production of ADC foaming agents. Compared with existing technologies, it can effectively improve the recovery rate of COD and ammonia nitrogen in wastewater, reduce environmental pollution, and has certain economic benefits.

[0015] This invention uses an impurity filter to replace the original steam and water to filter the filtrate in the initial slurry collection tank, avoiding the consumption of steam and water and the increase in filtrate volume; the impurity filter extracts the clear liquid from the upper layer of the initial slurry collection tank for filtration, which can reduce the use of the impurity filter and improve the filtration quality; connecting the later slurry collection tank directly to the reactor can improve the filtration quality.

[0016] This invention allows the later-stage slurry to be directly fed into the reactor, effectively improving the utilization rate of the active ingredients. Solenoid valves and flow meters replace the original manual valves, controlling the on / off state of the solenoid valves according to the reactor's liquid demand. Compressed air is added to the pipe bends to purge the pipes after each liquid supply, preventing blockage by high-salt slurry precipitates. Attached Figure Description

[0017] The features and advantages of the invention will be more clearly understood by referring to the accompanying drawings, which are schematic and should not be construed as limiting the invention in any way. In the drawings:

[0018] Figure 1 This is a schematic diagram of the structure of an existing slurry pretreatment and recovery device;

[0019] Figure 2 This is a schematic diagram of the slurry pretreatment and recovery device of the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] This invention provides a slurry pretreatment and recovery device, comprising: a cooling assembly, an initial filtration assembly, and a final filtration assembly; as shown below. Figure 2 As shown, the cooling components include: a slurry circulation pump 11 and a cooling tower 12; the initial filtration components include: a clear liquid pump 21, a microporous PE filter 22, a slurry pump 23, and an initial slurry filtration tank 24; the subsequent filtration components include: a slurry transfer pump 31, a reaction vessel 32, a vacuum filter 33, a slurry preparation tank 34, a slurry solenoid valve 35, a flow meter 36, a compressed air inlet 37, a compressed air solenoid valve 38, and a controller;

[0022] The filtrate is discharged from the filtrate outlet of the reactor 32. At this time, the filtrate contains filter residue. The filtrate first passes through the vacuum belt filter 33 to filter out part of the filter residue. The filter residue enters the slurry preparation tank 34 through the slag discharge port. The filtrate is discharged into the initial slurry collection tank through the filtrate outlet. The filtrate in the initial slurry collection tank has a higher temperature. The slurry circulation pump 11 draws the filtrate from the initial slurry collection tank into the cooling tower 12. The cooling tower 12 cools the filtrate and then sprays it back into the initial slurry collection tank. At this time, the filtrate partially crystallizes due to cooling. The crystals precipitate in the initial slurry collection tank, and the filtrate in the initial slurry collection tank is divided into upper and lower layers. The upper layer is a relatively clear upper clear liquid layer, and the lower layer is a lower slurry layer mixed with crystals. The upper clear liquid layer contains fewer impurities. It is drawn into the microporous PE filter 22 by the clear liquid pump 21. The relatively clear upper clear liquid can effectively reduce the filtration load of the microporous PE filter 22, thus reducing the use of the microporous PE filter 22. The number of samples is small, and the upper clear liquid contains less effective ingredients. After being filtered by the microporous PE filter 22, the filtrate discharged into the filtrate collection tank will also effectively reduce the loss of effective ingredients and reduce the COD and ammonia nitrogen content. The slurry pump 23 draws the lower slurry layer in the initial slurry collection tank to the initial slurry filter tank 24 for filtration. The filtrate filtered by the initial slurry filter tank 24 is discharged into the initial slurry collection tank, and the filter residue is discharged into the later slurry collection tank. When the reactor 32 needs to be replenished with slurry, the controller controls the slurry conduction solenoid valve 35 to open, and the slurry delivery pump 31 then draws the filtrate in the later slurry collection tank into the reactor 32 for reuse. The flow meter 36 obtains the amount of slurry injected in real time. When the required amount of the reactor 32 is reached, the controller controls the slurry conduction solenoid valve 35 to close, and the slurry delivery pump 31 stops. At this time, the air compressor conduction solenoid valve 38 is opened to blow air into the pipeline to clean the precipitates in the pipeline. Although the filtrate in the later slurry collection tank may have a high salt content at this stage, it can be repeatedly washed by a vacuum filter after passing through the reactor, which can improve the utilization rate of the effective components in the filtrate.

[0023] Taking the filtration of biuret in the ADC production process as an example, biuret is a suspension containing COD and ammonia nitrogen.

[0024] The following is a data comparison between the present invention and the prior art in actual production process:

[0025] Table 1 below shows the daily filtrate requirements:

[0026]

[0027] Table 1

[0028] The effectiveness of existing methods in filtration and recovery of the above filtrate is shown in Tables 2 and 3 below:

[0029]

[0030] Table 2

[0031]

[0032] Table 3

[0033] As shown in Tables 2 and 3, processing 820 tons of filtrate requires 3 tons of steam and 28 tons of tap water to obtain 5 tons of filter residue, which is the product to be recovered. This consumption is relatively large. The filtered filtrate still contains high levels of ammonia nitrogen and COD, and since the products to be recovered include ammonia nitrogen and COD, a significant amount of ammonia nitrogen and COD are wasted, resulting in low overall recovery efficiency. Furthermore, the addition of large amounts of water and steam during the filter residue acquisition process actually increases the amount of waste filtrate after filtration, significantly raising the cost of waste filtrate treatment.

[0034] The effects of this invention on the filtration and recovery of the above-mentioned filtrate are shown in Tables 4 and 5 below:

[0035]

[0036] Table 4

[0037]

[0038] Table 5

[0039] As shown in Tables 4 and 5, 820 tons of filtrate requires no steam consumption and only 0.5 tons of tap water to obtain 7.5 tons of filter cake, the product to be recovered, increasing the recovery rate by 0.3%. This significantly reduces consumption while improving the recovery rate. Simultaneously, the filtrate is recycled, primarily from the supernatant, further increasing its utilization rate and the recovery rate of filter cake, thus avoiding waste. Due to the increased recovery of the product, the ammonia nitrogen and COD levels in the filtered filtrate are significantly reduced. Since no large amounts of water or steam are added during the filter cake acquisition process, and some filtrate is recycled, the amount of waste filtrate is significantly reduced, lowering the cost of waste filtrate treatment.

[0040] Comparative data shows that, compared with existing methods, the present invention significantly improves the filter residue recovery rate; greatly reduces the amount of steam and tap water required for filtration; and significantly reduces the ammonia nitrogen and COD content in the waste filtrate, thereby lowering the treatment cost.

[0041] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A slurry pretreatment and recovery device for treating slurry during the production of ADC foaming agent, characterized in that, include: The system comprises a cooling assembly, a primary filtration assembly, and a secondary filtration assembly. The inlet and outlet of the cooling assembly are both connected to the primary slurry collection tank. The primary filtration assembly filters and separates the upper clear liquid from the primary slurry collection tank, with the filtrate recycled to the filtrate collection tank and the filter residue recycled to the secondary slurry collection tank. The primary filtration assembly also filters and separates the lower slurry from the primary slurry collection tank, with the filtrate recycled to the primary slurry collection tank and the filter residue recycled to the secondary slurry collection tank. The secondary filtration assembly includes a reaction vessel, a slurry separator, a slurry preparation tank, and a solenoid valve. The system includes a flow meter and a controller. The slurry inlet of the reactor is connected to the later slurry collection tank, and the filtrate outlet is connected to the inlet of the sludge-liquid separator. The filtrate outlet of the sludge-liquid separator is connected to the initial slurry collection tank, and the sludge outlet is connected to the slurry preparation tank. The later filtration treatment group filters and separates the liquid in the later slurry collection tank. The solenoid valve and flow meter are installed in the pipeline connecting the later slurry collection tank to the slurry inlet of the reactor. The solenoid valve and flow meter are connected to the controller. The controller controls the opening and closing of the solenoid valve based on the slurry demand of the reactor and the metering of the flow meter.

2. The slurry pretreatment and recovery device as described in claim 1, characterized in that, The initial filtration treatment assembly includes an impurity filter and an initial slurry filter tank; the inlet of the impurity filter is connected to the initial slurry collection tank, the slag discharge port is connected to the later slurry collection tank, and the liquid outlet is connected to the filtrate collection tank; the inlet of the initial slurry filter tank is connected to the initial slurry collection tank, the liquid outlet is connected to the initial slurry collection tank, and the slag discharge port is connected to the later slurry collection tank.

3. The slurry pretreatment and recovery device as described in claim 2, characterized in that, The inlet of the impurity filter is connected to the upper clear liquid layer of the initial slurry collection tank; the inlet of the initial slurry filter is connected to the lower slurry layer of the initial slurry collection tank.

4. The slurry pretreatment and recovery device as described in claim 1, characterized in that, Compressed air is introduced at the bend of the pipe from the later slurry collection tank to the slurry inlet of the reactor, and a solenoid valve is installed in the compressed air inlet pipe. The solenoid valve is connected to the controller, and controls the air compressor injection state based on the controller's control signal.

5. The slurry pretreatment and recovery device as described in claim 3, characterized in that, The impurity filter is a microporous PE filter.

6. The slurry pretreatment and recovery device as described in claim 1, characterized in that, The sludge-liquid separator is a vacuum belt filter.

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