A dewaterer for a desulphurisation system

Abstract

The utility model relates to desulfurization technical field, concretely relates to a dewatering machine of desulfurization system, including belt type drive unit and sectional vacuum chamber, and belt drive unit includes transmission wheel and the belt that winds on transmission wheel, is equipped with filter cloth with the friction contact of belt on the belt, and the sectional vacuum chamber is arranged in the space surrounded by filter cloth, and sectional vacuum chamber is segmented along the direction of travel of filter cloth, the dewatering machine of desulfurization system of the utility model is improved to the vacuum chamber in the drive traditional vacuum dewatering machine, makes it have better stability, reduces the fluctuation range of vacuum degree, avoids too many calcium sulfate dihydrate fine particles in the dewatering process to be vacuumed away, reduces the adhesion of gypsum particle on filter cloth, and the quality of gypsum is more easily controlled, reduces operating cost.

Description

Technical Field

[0001] This utility model relates to the field of desulfurization technology, specifically to a dehydrator for a desulfurization system. Background Technology

[0002] Desulfurization systems are a crucial component of coal-fired power plants, and their effectiveness directly impacts whether flue gas emissions meet environmental standards. Currently, the most common desulfurization process is the gypsum-based process. Its working principle involves mixing limestone powder with water to create a slurry, which reacts with sulfur dioxide to produce calcium sulfate. Once the calcium sulfate reaches a certain saturation point, it crystallizes to form calcium sulfate dihydrate. This calcium sulfate dihydrate is then desulfurized using a vacuum belt dehydrator to produce calcium sulfate, or gypsum. Gypsum is a widely used industrial and building material that can generate economic benefits for power plants. Therefore, the quality of the gypsum is particularly important.

[0003] The gypsum slurry produced by existing wet desulfurization technology is all processed by a vacuum belt dewatering machine. The dewatering efficiency directly affects the quality of the gypsum and the operating cost of the system. However, the current traditional vacuum belt dewatering machine uses a single vacuum chamber. During the dewatering process, most of the free water in the gypsum slurry can be removed in the first part of the single vacuum chamber. However, in the subsequent air extraction process in the single vacuum chamber, the vacuum degree remains unchanged, which leads to the removal of too many fine calcium sulfate dihydrate particles. The gypsum formed subsequently is difficult to shape, and the quality of the gypsum is difficult to control. In addition, the high adhesion between the filter cloth and the formed gypsum makes it difficult for some gypsum to detach in time, making filter cloth cleaning more difficult and increasing operating costs.

[0004] Therefore, there is an urgent need for a dehydrator that improves the vacuum chamber of traditional vacuum dehydrators to make it more stable, reduce the fluctuation range of vacuum degree, prevent excessive calcium sulfate dihydrate fine particles from being drawn away by vacuum during the dehydration process, reduce the adhesion of gypsum particles on the filter cloth, make the quality of gypsum easier to control, and reduce operating costs. Utility Model Content

[0005] The present invention aims to provide a dehydrator that improves the vacuum chamber of a traditional vacuum dehydrator, making it more stable, reducing the fluctuation range of vacuum degree, preventing excessive calcium sulfate dihydrate particles from being drawn away by vacuum during the dehydration process, reducing the adhesion of gypsum particles to the filter cloth, making the quality of gypsum easier to control, and reducing operating costs.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: it includes a belt drive unit and a segmented vacuum chamber. The belt drive unit includes a drive wheel and a belt wound around the drive wheel. A filter cloth is provided on the belt and in frictional contact with the belt. A segmented vacuum chamber is set in the space enclosed by the filter cloth. The segmented vacuum chamber is segmented along the travel direction of the filter cloth.

[0007] The beneficial effects of this solution are as follows: The traditional single vacuum chamber is improved into a segmented structure along the filter cloth's travel direction. This allows the gypsum slurry to experience suction at different vacuum levels during dewatering. In the initial dewatering stage, a higher vacuum level can be used to quickly remove free water, while in subsequent stages, the segmented structure prevents excessive suction and loss of fine particles. The segmented design also reduces the vacuum adsorption force between the filter cloth and the gypsum, thereby reducing gypsum adhesion and improving filter cloth cleaning. This effectively controls the loss rate of gypsum particles, improves the molding quality of the finished gypsum product, and simultaneously reduces filter cloth maintenance frequency and system energy consumption.

[0008] Furthermore, it also includes three pumping pipes. The segmented vacuum chamber includes a high vacuum zone, a medium vacuum zone, and a low vacuum zone. Seal baffles are provided between adjacent vacuum zones. A vacuum pump is provided on one side of the segmented vacuum chamber. The vacuum pump is connected to the three vacuum zones respectively through the pumping pipes.

[0009] Furthermore, the connection between the segmented vacuum chamber and the pumping pipe is provided with pumping holes. The density of pumping holes in the medium vacuum region is less than that in the high vacuum region but greater than that in the low vacuum region.

[0010] Furthermore, a buffer chamber is provided between the vacuum pump and the evacuation pipe. The buffer chamber is connected to the evacuation ports on the three vacuum zones through three evacuation pipes, and the vacuum pump and the buffer chamber are connected through the main evacuation pipe.

[0011] Furthermore, the negative pressure generated in the high vacuum region is -95 kPa to -85 kPa, the negative pressure generated in the medium vacuum region is -75 kPa to -65 kPa, and the negative pressure generated in the low vacuum region is -55 kPa to -45 kPa.

[0012] Furthermore, a guide vane inclined towards the high vacuum region is provided in the medium vacuum region, and the inclination angle between the guide vane and the bottom of the segmented vacuum chamber is 15° to 30°.

[0013] Furthermore, the filter cloth includes a fine layer on the top surface and a flow guiding layer on the bottom surface. Both the fine layer and the flow guiding layer are mesh-like, with a mesh spacing of 2mm to 5mm for the fine layer and a mesh spacing of 10mm to 20mm for the flow guiding layer.

[0014] Furthermore, a hydrophobic coating is sprayed on top of the fine layer, with a coating thickness of less than or equal to 50µm. Attached Figure Description

[0015] Figure 1 This is a side view of the present invention; Figure 2 This is a top view of the present invention; Figure 3 This is a schematic diagram of the filter cloth structure of this utility model.

[0016] The following detailed description illustrates the specific implementation method: The reference numerals in the accompanying drawings include: 1. Drive wheel; 2. Belt; 3. Filter cloth; 4. Segmented vacuum chamber; 5. High vacuum zone; 6. Medium vacuum zone; 7. Low vacuum zone; 8. Sealing baffle; 9. Evacuation pipe; 10. Vacuum pump; 11. Buffer chamber; 12. Main evacuation pipe; 13. Guide plate; 14. Fine layer; 15. Guide layer; 16. Hydrophobic coating; 17. Evacuation port. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0018] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model 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. Therefore, they should not be construed as limitations on this utility model.

[0019] The basic implementation examples are as follows: Figure 1-3 As shown, Figure 1 The dewatering machine of the desulfurization system shown includes a belt drive unit and a segmented vacuum chamber 4. The belt drive unit includes a drive wheel 1 and a belt 2 wound around the drive wheel 1. A filter cloth 3 is provided on the belt 2 and in frictional contact with the belt 2. The segmented vacuum chamber 4 is arranged within the space enclosed by the filter cloth 3. The segmented vacuum chamber 4 is segmented along the travel direction of the filter cloth 3. The drive wheel 1 in the belt drive unit can be made of metal or high-strength composite material, and its surface can be provided with anti-slip texture to enhance the friction with the belt 2. The belt 2 is preferably made of corrosion-resistant rubber material, and its thickness can be adjusted according to the load requirements. The contact method between the filter cloth 3 and the belt 2 can be assisted by pressure rollers for fixation. The pressure of the pressure rollers can be adjusted to adapt to different working conditions. Pressure roller-assisted fixation is a publicly available prior art method and will not be described in detail here. The number of segments in the segmented vacuum chamber 4 can be set to 3 to 5 segments according to the dewatering requirements. Each segment is connected by a flexible seal to allow for slight deformation of the belt 2 during operation. The shell of the vacuum chamber can be made of stainless steel welded structure, and wear-resistant lining plates can be installed inside. As a preferred embodiment, the segmented vacuum chamber 4 is divided into 3 segments.

[0020] By modifying the traditional single vacuum chamber into a segmented structure along the travel direction of the filter cloth 3, the gypsum slurry can undergo suction at different vacuum levels during dewatering. In the initial dewatering stage, a higher vacuum level can be used to quickly remove free water, while in subsequent stages, the segmented structure prevents excessive suction and loss of fine particles. The segmented design also reduces the vacuum adsorption force between the filter cloth 3 and the gypsum, thereby reducing gypsum adhesion and improving the cleaning effect of the filter cloth 3. This effectively controls the loss rate of gypsum particles, improves the molding quality of the finished gypsum, and simultaneously reduces the maintenance frequency of the filter cloth 3 and system energy consumption.

[0021] In this embodiment, the segmented vacuum chamber 4 includes a high vacuum zone 5, a medium vacuum zone 6, and a low vacuum zone 7. A sealing baffle 8 is provided between adjacent vacuum zones. A vacuum pump 10 is provided on one side of the segmented vacuum chamber 4, and the vacuum pump 10 is connected to each of the three vacuum zones via a suction pipe 9. In a preferred embodiment, the sealing baffle 8 can be made of rubber or polyurethane material with a thickness of 5mm to 10mm. The sealing baffle 8 can be fixed to the inner wall of the vacuum chamber by bolts. The vacuum pump 10 can be an existing liquid ring vacuum pump, and the suction pipe 9 can be made of stainless steel with an inner diameter of 50mm to 80mm. In a preferred embodiment, the length ratio of the high vacuum zone 5, the medium vacuum zone 6, and the low vacuum zone 7 in the direction of travel of the filter cloth 3 is 1:1:1, where the high vacuum zone 5 is located at the front of the filter cloth 3 in the direction of travel, and the low vacuum zone 7 is located at the rear of the filter cloth 3 in the direction of travel. The suction pipe 9 can be connected to the three vacuum zones in parallel, and a regulating valve can be provided on each branch to assist in controlling the suction volume of each zone.

[0022] By setting three zones with different vacuum levels, gradient control of the gypsum slurry dewatering process can be achieved. In the high vacuum zone 5, most free water is rapidly removed; in the medium vacuum zone 6, bound water is moderately removed; and in the low vacuum zone 7, final dewatering and molding are completed. This segmented vacuum control method effectively avoids the loss of fine particles due to excessive suction, while also reducing the adhesion of gypsum to the filter cloth 3. Compared to a single vacuum chamber, this solution significantly improves the uniformity and quality stability of gypsum molding, while reducing the frequency of filter cloth 3 cleaning and lowering operating energy consumption.

[0023] In this embodiment, a suction port 17 is provided at the connection between the segmented vacuum chamber 4 and the suction pipe 9. The density of the suction ports 17 in the medium vacuum region 6 is less than that in the high vacuum region 5 but greater than that in the low vacuum region 7. The arrangement of the suction ports 17 at the connection between the vacuum chamber and the suction pipe 9 adopts a differentiated distribution design. For example, in the high vacuum region 5, the suction ports 17 are arranged at a higher density, with 80 to 100 suction ports 17 arranged per square meter; in the medium vacuum region 6, the density of the suction ports 17 is appropriately reduced, with 35 to 70 suction ports 17 arranged per square meter; in the low vacuum region 7, the density of the suction ports 17 is further reduced, with 10 to 20 suction ports 17 arranged per square meter. In a preferred embodiment, the high vacuum zone 5 has 96 extraction holes 17, the medium vacuum zone 6 has 48 extraction holes 17, and the low vacuum zone 7 has 18 extraction holes 17. The diameter of the extraction holes 17 can be controlled within the range of 5mm to 10mm, and the extraction holes 17 in each zone can be arranged with the same diameter but different spacing. In addition, the extraction holes 17 can take various shapes such as circular, elliptical, or elongated, wherein the length direction of the elongated extraction holes 17 should preferably be consistent with the travel direction of the filter cloth 3.

[0024] This technical solution achieves gradient control of vacuum level by adjusting the density of the extraction holes 17 in different vacuum zones. In the high vacuum zone 5, a higher density of extraction holes 17 is used to quickly extract a large amount of free water. In the medium vacuum zone 6, the density of the extraction holes 17 is appropriately reduced to avoid excessive extraction leading to the loss of fine calcium sulfate dihydrate particles. In the low vacuum zone 7, the density of the extraction holes 17 is further reduced, which helps control the vacuum level in the final dehydration stage. This design ensures that the gypsum slurry achieves a suitable vacuum level in different dehydration stages, guaranteeing dehydration efficiency, reducing the loss of fine particles, and decreasing the adhesion of gypsum to the filter cloth 3. Compared with existing technologies, this solution effectively solves the problem of difficult precise control of vacuum level during the dehydration process in traditional single-vacuum chamber dehydrators, improving the quality stability of gypsum molding.

[0025] In this embodiment, a buffer chamber 11 is provided between the vacuum pump 10 and the suction pipe 9. The buffer chamber 11 is connected to the suction holes 17 on the three vacuum zones through the three suction pipes 9 respectively. The vacuum pump 10 and the buffer chamber 11 are connected through the main suction pipe 12. During the operation of the vacuum pump 10, the buffer chamber 11 stabilizes the vacuum zone when the vacuum level fluctuates, ensuring the stable operation of the vacuum pump 10. The size of the buffer chamber 11 can be selected according to the power of the vacuum pump 10 and the actual required vacuum level, which will not be described in detail here.

[0026] In this embodiment, the negative pressure generated in the high vacuum zone 5 is -95 kPa to -85 kPa, the negative pressure generated in the medium vacuum zone 6 is -75 kPa to -65 kPa, and the negative pressure generated in the low vacuum zone 7 is -55 kPa to -45 kPa. The negative pressure range is achieved by matching the pumping capacity of the vacuum pump 10 with the diameter of the pumping pipe 9. The negative pressure in the high vacuum zone 5 is achieved by increasing the density of the pumping holes 17 or extending the pumping time. The negative pressure in the medium vacuum zone 6 is achieved by adjusting the spacing of the pumping holes 17 or by using a multi-stage vacuum pump 10. The negative pressure in the low vacuum zone 7 is achieved by reducing the number of pumping holes 17 or reducing the power of the vacuum pump 10. As a preferred embodiment, the negative pressure value of each vacuum zone can be monitored in real time by a pressure sensor, and the operating parameters of the vacuum pump 10 can be dynamically adjusted by an existing PLC control system to maintain a stable negative pressure. For example, the high vacuum zone 5 uses -90 kPa as the reference value, the medium vacuum zone 6 uses -70 kPa as the reference value, and the low vacuum zone 7 uses -50 kPa as the reference value. The negative pressure values ​​of the three zones are allowed to fluctuate by ±5 kPa.

[0027] By setting up graded negative pressure zones, progressive suction is achieved during the dehydration process. High vacuum zone 5 rapidly removes free water from the gypsum slurry, medium vacuum zone 6 gently separates bound water to prevent the loss of fine particles, and low vacuum zone 7 completes the final dehydration and shaping. This solution effectively solves the problem of excessive gypsum particle suction caused by traditional single vacuum chambers. By precisely controlling the negative pressure intensity at different dehydration stages, it ensures dehydration efficiency while reducing the loss of fine calcium sulfate dihydrate particles, and simultaneously lowers the adhesion strength of gypsum on the filter cloth 3.

[0028] In this embodiment, a guide plate 13 inclined towards the high vacuum zone 5 is provided in the medium vacuum zone 6. The inclination angle between the guide plate 13 and the bottom of the segmented vacuum chamber 4 is 15° to 30°. The guide plate 13 can be made of stainless steel or engineering plastic, and its surface can be polished to reduce flow resistance. The installation method of the guide plate 13 includes, but is not limited to: fixing it to the side wall of the vacuum chamber with bolts, welding it to the internal bracket of the vacuum chamber, or using an adjustable hinge mechanism. The choice can be made according to the actual situation and will not be elaborated here. As a preferred embodiment, both ends of the guide plate 13 are connected to the adjacent sealing baffles 8. The sealing baffle 8 near the low vacuum zone 7 is connected to one end of the guide plate 13 at the connection with the bottom of the medium vacuum zone 6, and the other end of the guide plate 13 is connected to the sealing baffle 8 near the high vacuum zone 5. A rubber sealing strip can be provided on the edge of the guide plate 13 to prevent airflow short circuit (abnormal airflow path).

[0029] This technical solution effectively guides the flow direction of gypsum slurry by setting a guide plate 13 at a specific angle in the medium vacuum zone 6. When the slurry moves from the medium vacuum zone 6 to the low vacuum zone 7, the inclined channel formed by the guide plate 13 accelerates the directional flow of the slurry while reducing turbulence. As a result, gypsum particles maintain a more stable deposition state during movement, preventing excessive suction of fine particles. The angle design of the guide plate 13 ensures flow efficiency while preventing slurry retention caused by excessive angle. This structure, combined with the pressure gradient of the segmented vacuum chamber 4, achieves improved solid-liquid separation efficiency and stable control of gypsum quality during the gypsum dehydration process.

[0030] In this embodiment, the filter cloth 3 includes a fine layer 14 on the top surface and a flow guiding layer 15 on the bottom surface. Both the fine layer 14 and the flow guiding layer 15 are mesh-like. The mesh spacing of the fine layer 14 is 2mm to 5mm, and the mesh spacing of the flow guiding layer 15 is 10mm to 20mm. The fine layer 14 is made using a high-density weaving process, and the mesh spacing is controlled within the range of 2mm to 5mm. This allows the airflow from the vacuum pump to pass through and can effectively intercept gypsum particles, preventing the gypsum particles from sinking and being vacuumed away. The flow-guiding layer 15 can be made of PVC material, using a low-density weaving process with a mesh spacing of 10mm to 20mm, facilitating rapid water passage. The flow-guiding layer 15 also supports the upper fine layer 14 to prevent sagging, maintaining the overall flatness of the filter cloth 3 and reducing the risk of misalignment. The fine layer 14 and the flow-guiding layer 15 are composited through a hot-pressing process to form a stable double-layer structure. The filter cloth 3 with the fine layer 14 and the flow-guiding layer 15 can be cleaned using existing pulse backflushing technology, improving the cleanliness of the filter cloth 3 during rinsing and reducing the difficulty of cleaning. By setting a double-layer filter cloth 3 structure with different mesh spacings, the fine layer 14 can effectively intercept gypsum particles, while the flow-guiding layer 15 ensures dewatering efficiency, making the molded gypsum easier to shape and achieving stable control of gypsum quality.

[0031] In this embodiment, a hydrophobic coating 16 is sprayed onto the top of the fine layer 14, with a coating thickness not exceeding 50µm. The hydrophobic coating 16 can be prepared using materials such as nano-silicon carbide, polytetrafluoroethylene, silicone resin, or fluorocarbon resin. The spraying process can be carried out by air spraying, electrostatic spraying, or dip coating. As a preferred embodiment, the coating thickness is controlled within the range of 20µm to 45µm to ensure the hydrophobic effect while avoiding affecting the air permeability of the filter cloth 3. The surface of the hydrophobic coating 16 can also be subjected to micron-level roughening treatment to enhance the hydrophobic performance.

[0032] By applying a hydrophobic coating 16 to the surface of the fine layer 14 of the filter cloth 3, the adhesion between gypsum particles and the surface of the filter cloth 3 can be effectively reduced. When the gypsum slurry undergoes dewatering, the hydrophobic coating 16 reduces the deposition of gypsum crystals on the surface of the filter cloth 3, making it easier to peel the molded gypsum from the filter cloth 3. Controlling the coating thickness to below 50µm can avoid clogging the pores of the filter cloth 3 and ensure dewatering efficiency. This technical solution solves the problem of gypsum easily adhering to the filter cloth 3 in traditional dewatering machines, leading to difficult cleaning, and improves the integrity of gypsum products and the stability of system operation.

[0033] The above descriptions are merely embodiments of the present invention, and common knowledge such as specific technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A dehydrator for a desulfurization system, characterized in that: It includes a belt drive unit and a segmented vacuum chamber. The belt drive unit includes a drive wheel and a belt wound around the drive wheel. A filter cloth is provided on the belt and comes into frictional contact with the belt. The segmented vacuum chamber is set in the space enclosed by the filter cloth and is segmented along the travel direction of the filter cloth.

2. The dehydrator of a desulfurization system according to claim 1, characterized in that: It also includes three pumping pipes. The segmented vacuum chamber includes a high vacuum zone, a medium vacuum zone, and a low vacuum zone. Seal baffles are installed between adjacent vacuum zones. A vacuum pump is installed on one side of the segmented vacuum chamber. The vacuum pump is connected to the three vacuum zones through three pumping pipes.

3. The dehydrator of a desulfurization system according to claim 2, characterized in that: The segmented vacuum chamber is equipped with evacuation ports at the connection between the evacuation pipe and the vacuum chamber. The density of evacuation ports in the medium vacuum region is less than that in the high vacuum region but greater than that in the low vacuum region.

4. The dehydrator of a desulfurization system according to claim 2, characterized in that: A buffer chamber is provided between the vacuum pump and the evacuation pipe. The buffer chamber is connected to the evacuation ports on the three vacuum zones through three evacuation pipes. The vacuum pump and the buffer chamber are connected through the main evacuation pipe.

5. The dehydrator of a desulfurization system according to claim 2, characterized in that: The negative pressure generated in the high vacuum region is -95 kPa to -85 kPa, the negative pressure generated in the medium vacuum region is -75 kPa to -65 kPa, and the negative pressure generated in the low vacuum region is -55 kPa to -45 kPa.

6. The dehydrator of a desulfurization system according to claim 2, characterized in that: The medium vacuum region is equipped with a guide plate that is inclined towards the high vacuum region. The inclination angle between the guide plate and the bottom of the segmented vacuum chamber is 15° to 30°.

7. The dehydrator of a desulfurization system according to claim 1, characterized in that: The filter cloth includes a fine layer on the top surface and a flow guiding layer on the bottom surface. Both the fine layer and the flow guiding layer are mesh-like. The mesh spacing of the fine layer is 2mm to 5mm, and the mesh spacing of the flow guiding layer is 10mm to 20mm.

8. The dehydrator of a desulfurization system according to claim 7, characterized in that: A hydrophobic coating is sprayed on top of the fine layer, and the thickness of the hydrophobic coating is less than or equal to 50µm.

Images