A drum filter

Abstract

This utility model relates to an expansion drum filter comprising a cylindrical shell, a support cage, a bag-shaped filter membrane, and tangential nozzles. The liquid to be filtered enters the filtration zone through the inlet pipe. The fluid force of the filtrate compresses the bag-shaped filter membrane towards the arc-shaped section, trapping the filter residue on the surface of the bag-shaped filter membrane. After filtration stops, the bag-shaped filter membrane is backwashed, expanding into a drum shape. The filter residue detaches from the bag-shaped filter membrane and settles into a conical hopper. Multiple downward-sloping tangential nozzles with pipelines connected to the clear liquid zone are arranged circumferentially on the inner wall of the conical hopper. The ejected fluid forms a tangential vortex, which washes the inner wall of the conical hopper, effectively peeling off and preventing the accumulation and adhesion of solid residue on the inner wall of the conical hopper. It also guides the settled residue to vortex and gather towards the slag discharge pipe, improving slag discharge efficiency and reliability, ensuring continuous and stable operation of the filtration process, reducing the frequency of equipment downtime maintenance, and lowering operating and maintenance costs.

Description

Technical Field

[0001] This utility model relates to the field of solid-liquid separation technology, and in particular to an expansion drum filter. Background Technology

[0002] In the existing technology of drum filters, the principle is to use a tube sheet inside a cylindrical shell to separate the clear liquid zone and the filtration zone. The liquid enters through the inlet pipe on the side of the filtration zone, and after being filtered by the bag filter membrane, the clear liquid rises to the clear liquid zone and is discharged from the overflow pipe, while the solid residue is trapped on the surface of the filter membrane. During the backwashing process, the bag filter membrane expands into a drum shape due to the potential energy of the filtrate level difference. Under the action of the backwashing potential energy, the filter residue attached to the filter membrane settles to the bottom conical hopper and is finally discharged through the slag discharge pipe. The inner wall of the conical hopper lacks a cleaning mechanism during the slag discharge process, and the residue is easy to accumulate and stick to the hopper wall, resulting in poor slag discharge and blockage, which affects the filtration efficiency and continuous operation of the equipment.

[0003] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Utility Model Content

[0004] To address the shortcomings of existing technologies, this utility model discloses an expansion drum filter to solve the problem that the inner wall of the conical bucket lacks a cleaning mechanism during the slag discharge process, causing residues to easily accumulate and adhere to the bucket wall, resulting in poor slag discharge and blockage, which affects filtration efficiency and continuous operation of the equipment.

[0005] The technical solution adopted in this utility model is as follows:

[0006] An expansion drum filter, characterized in that it comprises:

[0007] A cylindrical shell is provided inside the cylindrical shell, and a tube sheet is provided inside the cylindrical shell. The tube sheet separates the interior of the cylindrical shell into a clear liquid zone and a filtration zone. Several mounting holes are provided on the tube sheet. A liquid inlet pipe is provided on the side of the filtration zone. A conical hopper is provided at the bottom of the filtration zone. A slag discharge pipe is provided at the bottom of the conical hopper. An overflow pipe is provided at the top of the clear liquid zone.

[0008] A support cage is provided within the filtration zone, with the top end of the support cage located in the mounting hole;

[0009] A bag-shaped filter membrane is fitted onto the outside of the support cage, and the top end of the bag-shaped filter membrane is detachably connected to the top end of the support cage.

[0010] A tangential nozzle, having at least two, wherein the at least two tangential nozzles are circumferentially disposed on the inner wall of the conical bucket, the tangential nozzles are inclined downward and toward the inner wall of the conical bucket, and the tangential nozzles communicate with the clear liquid zone.

[0011] A further technical solution is that a diversion pipe is provided on the outside of the cylindrical shell. The diversion pipe includes a main pipe and at least two secondary pipes. The top end of the main pipe is connected to the clear liquid zone, the bottom end of the main pipe is connected to the top ends of at least two of the secondary pipes, and the bottom end of the secondary pipes is connected to the tangential nozzle.

[0012] A further technical solution is that the diversion pipeline also includes a diversion valve, the bottom end of the main pipeline is connected to the input end of the diversion valve, and the top end of the secondary pipeline is connected to the output end of the diversion valve.

[0013] A further technical solution is that a binding groove is provided on the outer side of the top of the support cage, and the top of the bag-shaped filter membrane is bound and fixed in the binding groove.

[0014] A further technical solution is that the support cage includes several support sections connected vertically. Each support section includes two connecting rings arranged coaxially vertically and several arc-shaped sections connecting the connecting rings. The arc-shaped sections are arranged circumferentially along the connecting rings, and the openings of the arc-shaped sections are located away from the axis of the support section.

[0015] A further technical solution is that the support cage also includes several fixing grooves, the fixing grooves are located between two adjacent connecting rings, and the bag-shaped filter membrane is fixed in sections within the fixing grooves.

[0016] A further technical solution is that a compressed air inlet pipe is provided on the side of the filtration zone, and a backwash water inlet pipe is provided at the top of the clear liquid zone.

[0017] A further technical solution is that the bag-shaped filter membrane is made of porous polytetrafluoroethylene film.

[0018] The beneficial effects of this utility model embodiment are as follows:

[0019] (i) An expansion drum filter includes a cylindrical shell, a support cage, a bag-shaped filter membrane, and tangential nozzles. The liquid to be filtered enters the filtration zone through the inlet pipe. The fluid force of the filtrate compresses the bag-shaped filter membrane into the arc section, and the filter residue is trapped on the surface of the bag-shaped filter membrane. After filtration stops, the bag-shaped filter membrane is backwashed, and the bag-shaped filter membrane expands into a drum shape. The filter residue detaches from the bag-shaped filter membrane and settles into a conical hopper. Multiple downward-sloping tangential nozzles with pipelines connected to the clear liquid zone are arranged circumferentially on the inner wall of the conical hopper. The ejected fluid forms a tangential vortex. The vortex washes the inner wall of the conical hopper, effectively peeling off and preventing the accumulation and adhesion of solid residue on the inner wall of the conical hopper. It also guides the settled residue to vortex and gather towards the slag discharge pipe, improving the slag discharge efficiency and reliability, ensuring the continuous and stable operation of the filtration process, reducing the frequency of equipment downtime maintenance, and lowering the operation and maintenance costs.

[0020] (ii) Furthermore, the diversion pipeline also includes a diversion valve. The bottom end of the main pipeline is connected to the input end of the diversion valve, and the top end of the secondary pipeline is connected to the output end of the diversion valve. The diversion valve precisely adjusts the flow rate and pressure of the clean liquid distributed to each tangential nozzle, ensuring that the tangential swirling intensity generated by multiple nozzles is uniform and consistent, avoiding incomplete removal of residue from the inner wall of the conical bucket or the formation of flow dead zones due to insufficient local flushing force. At the same time, the flushing intensity can be flexibly adjusted according to the actual slag discharge requirements.

[0021] (iii) Furthermore, a compressed air inlet pipe is provided on the side of the filtration zone, and a backwash water inlet pipe is provided at the top of the clear liquid zone. During the backwashing stage, the compressed air inlet pipe injects high-pressure gas into the filtration zone, increasing the pressure difference between the inside and outside of the bag filter membrane. The backwash water inlet pipe injects backwash water from the top of the clear liquid zone. Due to the potential energy of the filtrate level difference, the bag filter membrane expands into a multi-section drum shape. Under the action of pore expansion and backwash potential energy, the bag filter membrane fully expands, peeling off the filter residue deeply embedded in the bag filter membrane, improving the regeneration efficiency of the bag filter membrane, and shortening the downtime.

[0022] (iv) Furthermore, the bag filter membrane is made of porous polytetrafluoroethylene (PTFE) membrane. The porous PTFE membrane can withstand the corrosion of strong acids, strong alkalis and organic solvents, ensuring long-term stable operation in harsh filtration environments. In addition, its inherent strong hydrophobicity reduces the adhesion of the filter cake and the liquid permeation resistance, thereby increasing the filtration flux of the filter membrane. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the internal structure of an expansion drum filter according to the present invention.

[0024] Figure 2 for Figure 1 Enlarged view at point A.

[0025] Figure 3 This is a rear view structural diagram of an expansion drum filter according to the present invention.

[0026] In the picture:

[0027] 100. Cylindrical shell; 110. Tube sheet; 111. Mounting hole; 120. Clear liquid zone; 121. Overflow pipe; 122. Backwash water inlet pipe; 130. Filtration zone; 131. Liquid inlet pipe; 132. Compressed air inlet pipe; 140. Conical hopper; 141. Slag discharge pipe; 200. Support cage; 210. Support section; 211. Connecting ring; 212. Arc-shaped section; 220. Bundling groove; 230. Fixing groove; 300. Bag filter membrane; 400. Tangential nozzle; 500. Diversion pipe; 510. Main pipe; 520. Secondary pipe; 530. Diversion valve. Detailed Implementation

[0028] To further illustrate the technical means and effects adopted by this utility model in order to achieve the intended utility model purpose, the following detailed description of the specific implementation methods, structure, features and effects of this utility model is provided in conjunction with the accompanying drawings and preferred embodiments.

[0029] First embodiment:

[0030] An expansion drum filter includes a cylindrical housing 100, a support cage 200, a bag-shaped filter membrane 300, and a tangential nozzle 400.

[0031] like Figure 1 As shown, a tube sheet 110 is provided inside the cylindrical shell 100. The tube sheet 110 divides the interior of the cylindrical shell 100 into a clear liquid zone 120 and a filtration zone 130. Several mounting holes 111 are provided on the tube sheet 110. A liquid inlet pipe 131 is provided on the side of the filtration zone 130, a conical hopper 140 is provided at the bottom of the filtration zone 130, a slag discharge pipe 141 is provided at the bottom of the conical hopper 140, and an overflow pipe 121 is provided at the top of the clear liquid zone 120.

[0032] like Figures 1-2 As shown, the support cage 200 is disposed within the filter zone 130, and the top end of the support cage 200 is disposed in the mounting hole 111. Exemplarily, the support cage 200 includes a plurality of vertically connected support sections 210. Each support section 210 includes two vertically coaxially arranged connecting rings 211 and a plurality of arc-shaped sections 212 connecting the connecting rings 211. The plurality of arc-shaped sections 212 are arranged circumferentially along the connecting rings 211, and the openings of the arc-shaped sections 212 are disposed away from the axis of the support section 210.

[0033] like Figures 1-2 As shown, the bag-shaped filter membrane 300 is sleeved on the outside of the support cage 200, and the top end of the bag-shaped filter membrane 300 is detachably connected to the top end of the support cage 200. For example, a binding groove 220 is provided on the outer side of the top end of the support cage 200, and the top end of the bag-shaped filter membrane 300 is bound and fixed within the binding groove 220. The support cage 200 also includes several fixing grooves 230, which are located between two adjacent connecting rings 211, and the bag-shaped filter membrane 300 is fixed in sections within the fixing grooves 230.

[0034] like Figure 1 and Figure 3As shown, there are at least two tangential nozzles 400, which are circumferentially disposed on the inner wall of the conical bucket 140. The tangential nozzles 400 are inclined downward and face the inner wall of the conical bucket 140, and are connected to the clear liquid zone 120. For example, a diversion pipe 500 is provided on the outer side of the cylindrical shell 100. The diversion pipe 500 includes a main pipe 510 and at least two secondary pipes 520. The top end of the main pipe 510 is connected to the clear liquid zone 120, the bottom end of the main pipe 510 is connected to the top end of the at least two secondary pipes 520, and the bottom end of the secondary pipes 520 is connected to the tangential nozzles 400.

[0035] like Figure 3 As shown, the diversion pipe 500 further includes a diversion valve 530. The bottom end of the main pipe 510 is connected to the input end of the diversion valve 530, and the top end of the secondary pipe 520 is connected to the output end of the diversion valve 530. The diversion valve 530 precisely adjusts the flow rate and pressure of the clean liquid distributed to each tangential nozzle 400, ensuring that the tangential swirling intensity generated by multiple nozzles is uniform and consistent, avoiding incomplete removal of residue from the inner wall of the conical bucket 140 or the formation of flow dead zones due to insufficient local flushing force. At the same time, the flushing intensity can be flexibly adjusted according to the actual slag discharge requirements.

[0036] like Figure 1 As shown, the side of the filtration zone 130 is further provided with a compressed air inlet pipe 132, and the top of the clear liquid zone 120 is provided with a backwash water inlet pipe 122. During the backwashing stage, the compressed air inlet pipe 132 injects high-pressure gas into the filtration zone 130, increasing the pressure difference between the inside and outside of the bag filter membrane 300. The backwash water inlet pipe 122 injects backwash water from the top of the clear liquid zone 120. Due to the potential energy of the filtrate level difference, the bag filter membrane 300 expands into a multi-section drum shape. Under the action of pore expansion and backwash potential energy, the bag filter membrane 300 fully expands, peeling off the filter residue deeply embedded in the bag filter membrane 300, improving the regeneration efficiency of the bag filter membrane 300, and shortening the downtime.

[0037] Furthermore, the bag filter membrane 300 is made of porous polytetrafluoroethylene (PTFE) membrane. The porous PTFE membrane can withstand the corrosion of strong acids, strong alkalis and organic solvents, ensuring long-term stable operation in harsh filtration environments. Its inherent strong hydrophobicity reduces filter cake adhesion and liquid permeation resistance, thereby increasing the filtration flux of the membrane.

[0038] In operation, this embodiment is as follows:

[0039] The liquid to be filtered first enters the cylindrical shell 100 through the inlet pipe 131 on the side of the filtration zone 130. After passing through the bag-shaped filter membrane 300 in the filtration zone 130, the filtrate rises to the clear liquid zone 120 and is discharged through the overflow pipe 121 at the top. The fluid force of the filtrate compresses the bag-shaped filter membrane 300 towards the arc-shaped section 212, and the filter residue is trapped on the surface of the bag-shaped filter membrane 300. When the filtration pressure difference increases or the set cycle is reached, filtration stops, and backwash water is injected through the backwash water inlet pipe 122 at the top of the clear liquid zone 120. Simultaneously, compressed air is injected through the compressed air inlet pipe 1... 32 enters the filtration zone 130. Under the action of air pressure and water pressure, the bag filter membrane 300 expands into a drum shape, causing the attached filter residue to loosen, fall off, and settle into the conical hopper 140. During the slag discharge stage, the slag discharge pipe 141 is opened. The backwash water in the clear liquid zone 120 is driven by the diversion valve 530 and transported through the outer diversion pipe 500 to the tangential nozzle 400 that is circumferentially set on the inner wall of the conical hopper 140 and tilted downwards. This forms a high-speed swirling flow that adheres to the wall, powerfully flushes the hopper wall, removes residual residue, and guides the residue to swirl and gather. Finally, it is completely discharged through the slag discharge pipe 141, completing the filtration cycle.

[0040] In this embodiment, multiple downward-sloping tangential nozzles 400 are arranged circumferentially on the inner wall of the conical hopper 140 and connected to the clear liquid zone 120. The ejected fluid forms a tangential vortex, which washes over the inner wall of the conical hopper 140, effectively peeling off and preventing the accumulation and adhesion of solid residue on the inner wall of the conical hopper 140. It also guides the settled residue to vortex and gather at the slag discharge pipe 141, improving slag discharge efficiency and reliability, ensuring continuous and stable operation of the filtration process, reducing the frequency of equipment downtime maintenance, and lowering operation and maintenance costs.

[0041] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present utility model. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the present utility model shall still fall within the scope of the present utility model.

Claims

1. A bellows filter characterized by, include: A cylindrical shell is provided inside the cylindrical shell, and a tube sheet is provided inside the cylindrical shell. The tube sheet separates the interior of the cylindrical shell into a clear liquid zone and a filtration zone. Several mounting holes are provided on the tube sheet. A liquid inlet pipe is provided on the side of the filtration zone. A conical hopper is provided at the bottom of the filtration zone. A slag discharge pipe is provided at the bottom of the conical hopper. An overflow pipe is provided at the top of the clear liquid zone. A support cage is provided within the filtration zone, with the top end of the support cage located in the mounting hole; A bag-shaped filter membrane is fitted onto the outside of the support cage, and the top end of the bag-shaped filter membrane is detachably connected to the top end of the support cage. A tangential nozzle, having at least two, wherein the at least two tangential nozzles are circumferentially disposed on the inner wall of the conical bucket, the tangential nozzles are inclined downward and toward the inner wall of the conical bucket, and the tangential nozzles communicate with the clear liquid zone.

2. The bellows filter of claim 1, wherein: The cylindrical shell is provided with a diversion pipe on its outer side. The diversion pipe includes a main pipe and at least two secondary pipes. The top end of the main pipe is connected to the clear liquid zone, and the bottom end of the main pipe is connected to the top ends of at least two of the secondary pipes. The bottom end of the secondary pipes is connected to the tangential nozzle.

3. The bellows filter of claim 2, wherein: The diversion pipeline also includes a diversion valve, with the bottom end of the main pipeline connected to the input end of the diversion valve and the top end of the secondary pipeline connected to the output end of the diversion valve.

4. The bellows filter of claim 1, wherein: The top outer side of the support cage is provided with a binding groove, and the top of the bag-shaped filter membrane is bound and fixed in the binding groove.

5. The bellows filter of claim 1, wherein: The support cage includes several support sections connected vertically. Each support section includes two connecting rings arranged coaxially vertically and several arc-shaped sections connecting the connecting rings. The arc-shaped sections are arranged circumferentially along the connecting rings, and the openings of the arc-shaped sections are located away from the axis of the support section.

6. The bellows filter of claim 5, wherein: The support cage also includes several fixing grooves, which are located between two adjacent connecting rings, and the bag-shaped filter membrane is fixed in sections within the fixing grooves.

7. The bellows filter of claim 1, wherein: The side of the filtration zone is also provided with a compressed air inlet pipe, and the top of the clear liquid zone is also provided with a backwash water inlet pipe.

8. The bellows filter of claim 1, wherein: The bag filter membrane is made of porous polytetrafluoroethylene film.

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