JP5374686B2 - Filtration type dehydrator - Google Patents

Description

  The present invention relates to a filtration dehydrator.

  Filter dehydrators are widely used as dehydrators for dewatering sludge generated from sewage treatment facilities. Since such a filtration type dehydrator is a method of dewatering sludge with a filter medium such as a filter cloth, the filtration surface of the filter medium is blocked by sludge particles or contaminants in the sludge, and the dewatering speed is reduced. Inconvenience occurs.

  As a technique for eliminating the problem of clogging of the filtration surface in such a filtration type dehydrator, for example, a screw is rotatably inserted and arranged inside a cylindrical screen, and back pressure is applied to the coagulated sludge by the rotation of this screw. In the screw press type sludge dewatering machine, which is transferred to the outside of the screen and discharges the filtrate to the outside of the screen, the cylindrical screen is formed into a coil shape by winding a wire material having a required elasticity. And a sludge dewatering machine (Japanese Patent Laid-Open No. 2000-288794).

  However, the sludge dehydrator requires a large amount of power to drive the screw, and the cleaning mechanism for eliminating or preventing the filtration surface blockage described above requires a large amount of power and water. Therefore, a high amount of energy is required.

  Also, in the sewage treatment facility, in addition to a dehydrator, in addition to a sufficient site area and building, a lot of ancillary equipment such as a conveyor system is required. There is a strong demand for a filtration dehydrator that is easy to maintain.

  That is, a filtration type dehydrator that satisfies all of the simple configuration, realization of energy saving, effective achievement of sludge dehydration, prevention of clogging of the filtration surface, and ease of maintenance has not yet been provided.

JP 2000-288794 A

  The present invention has been made in view of these inconveniences, and while achieving energy saving with a simple configuration, it is possible to achieve effective achievement of sludge dehydration and prevention of clogging of the filtration surface, and a filtration type that is easy to maintain and manage. The purpose is to provide a dehydrator.

The invention made to solve the above problems is
A sludge supply section for supplying sludge;
A filtration dewatering cylinder for filtering this sludge and separating it into dewatered sludge and desorbed liquid,
A casing for storing the filtration dewatering cylinder and the desorption liquid;
A vertical filtration dehydrator that is housed in the filtration dehydration cylinder and includes a screw having a central shaft and a wing portion;
The middle shaft is hollow and the upper end is sealed, and is not fixed to the casing,
A horizontal bearing portion for supporting the buoyancy caused by the sludge in the filtration dewatering cylinder and the screw that floats by the reaction reaction force of the sludge;
The inner surface of the filtration and dewatering cylinder is cleaned by a blade portion of a screw that is rotated by a reaction force of the sludge conveyance by the sludge supply section.

  In the filtration dehydrator, the middle shaft is hollow and sealed at the upper end, and is not fixed to the casing. Therefore, the sludge supplied from the sludge supply section is filled in the filtration dehydration cylinder. Can be lifted by sludge buoyancy and sludge transport reaction force. Further, by further providing a horizontal bearing portion for supporting the screw that floats by the buoyancy caused by sludge in the filtration dewatering cylinder and the reaction reaction force of the sludge, the screw that has floated due to the sludge filling in the filtration dehydration cylinder described above is provided. It is supported by a horizontal bearing portion, and the position of this screw can be maintained vertically. And, since the inner surface of the filtration dewatering cylinder is cleaned by the blades of the screw rotating by the reaction force of the sludge conveyance by the sludge supply unit, the filtration dehydrator is provided with a special drive mechanism for rotating the screw. In addition, the screw can be rotated efficiently and efficiently with only the reaction force of the sludge supply, and while achieving energy saving with a simple configuration, it is possible to effectively achieve sludge dewatering and prevent the clogging of the filtration surface. Easy management can be achieved at the same time.

  In the filtration dehydrator, the filtration dehydration cylinder and the casing include a low pressure filtration dehydration unit for maintaining a pressure loss through which the desorbed liquid passes through the filtration dehydration cylinder at a water column pressure of 10 m or less, and the filtration dehydration cylinder. The pressure drop through which the desorbed liquid passes is divided into a high pressure filtration dewatering section for maintaining the water column pressure at 10 m or more, and the differential pressure adjustment of the low pressure filtration dewatering section for adjusting the desorbed liquid discharge flow rate from the low pressure filtration dewatering section. It is preferable to further include a system and a high-pressure filtration dewatering unit internal pressure adjustment system that adjusts the amount of dewatered sludge discharged from the high-pressure filtration dewatering unit. The filtration dewatering cylinder and casing of the filtration dehydrator desorbs the low pressure filtration dehydration part for maintaining the pressure loss through which the desorbed liquid passes through the filtration dehydration cylinder at a water column pressure of 10 m or less, and the filtration dehydration cylinder. By separating the pressure loss through which the liquid passes into a high-pressure filtration dewatering unit for maintaining the water column pressure at 10 m or higher, the sludge is dewatered and effectively and reliably separated into the dewatered sludge and the desorbed liquid. Can do. Further, the filtration dehydrator includes a low pressure filtration dehydration unit differential pressure regulation system that regulates a desorbed liquid discharge flow rate from the low pressure filtration dehydration unit, and a high pressure filtration that regulates a dewatered sludge discharge amount from the high pressure filtration dehydration unit. By further including the dewatering part internal pressure adjusting system, it is possible to easily maintain effective and efficient sludge dewatering without reducing the sludge dewatering effect.

  In the filtration dehydrator, the filter medium constituting the filtration dewatering cylinder may be a wedge wire screen. In this way, the filtration material constituting the filtration dehydration cylinder is a wedge wire, so that the filtration dehydrator is effective for sludge dewatering while maintaining a simple configuration and reducing the size of the entire dehydrator. Achievement and prevention of clogging of the filtration surface can be further improved.

  As described above, the filtration type dehydrator of the present invention has a hollow screw shaft and a sealed upper end and is not fixed to the casing, and the sludge supplied from the sludge supply unit is removed from the filtration dehydration cylinder. The screw can be lifted by buoyancy by filling the inside. Further, by further providing a horizontal bearing portion for supporting the screw that floats by the buoyancy caused by sludge in the filtration dewatering cylinder and the reaction reaction force of the sludge, the screw that has floated due to the sludge filling in the filtration dehydration cylinder described above is provided. It is supported by a horizontal bearing portion, and the position of the screw can be maintained substantially vertical. Furthermore, since the inner surface of the filtration dewatering cylinder is cleaned by the blades of the screw rotating by the reaction force of the sludge conveyance by the sludge supply section, the filtration dehydrator of the present invention has a simple configuration and energy saving which are conventional problems. Realization, effective achievement of sludge dewatering, prevention of clogging of the filtration surface, and easy maintenance can be all solved.

It is a schematic structure figure showing a filtration type dehydrator concerning one embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. Note that the present invention is not limited to such an embodiment.

<Filtering dehydrator>
A filtration type dehydrator 1 shown in FIG. 1 is a vertical type dehydrator for dewatering sludge P and separating it into a desorbed liquid Q and dehydrated sludge R for processing. The filtration dehydrator 1 includes a sludge supply unit 2, a screw 3, a low pressure filtration dehydration unit 4, a high pressure filtration dehydration unit 5, a horizontal bearing unit 6, a low pressure filtration dehydration unit differential pressure adjustment system 7, and a high pressure filtration dehydration unit internal pressure regulation system. 8 is mainly provided. The type of sludge P is not particularly limited and includes, for example, primary sludge, excess sludge, digested sludge, septic tank sludge, coagulated sediment sludge, pressurized flotation sludge, organic sludge, etc. The sludge generated in the sludge treatment facility is preferable.

1. Sludge supply part The sludge supply part 2 is for supplying the sludge P to the inside of the filtration type dehydrator 1, and specifically, is a hole disposed at the lower end of the filtration type dehydrator 1. The shape and configuration of the sludge supply unit 2 are not particularly limited as long as the sludge P can be sufficiently supplied into the filtration dehydrator 1. Further, the means for supplying the sludge P is not particularly limited, and for example, a known technique such as a uniaxial screw pump or a centrifugal pump can be used.

2. Screw The screw 3 is accommodated in a low pressure filtration dehydration unit 4 and a high pressure filtration dehydration unit 5 which will be described later and is rotated by the supply reaction force of the sludge P supplied from the sludge supply unit 2 so that the sludge P is vertically oriented. It is a member for making it convey upward. Specifically, the screw 3 mainly includes a wing portion 9 and a middle shaft 10.

(Hanebe)
The wing portion 9 is a member disposed in a substantially spiral shape on the central shaft 10, and guides the sludge P from the lower side to the upper side of the filtration type dehydrator 1 along the filtration surface in the vertical direction, and the low pressure filtration dehydration described later. This is a member for preventing or reducing the blockage of the inner surface of the cylinder 11 and the inner surface of the high pressure filtration dehydration cylinder 12. About the raw material, shape, and structure of this wing part 9, it can fully implement | achieve the guidance to the vertical direction of the sludge P mentioned above, prevention or reduction of the obstruction | occlusion of the low pressure filtration dehydration cylinder 11 inner surface, and the high pressure filtration dehydration cylinder 12 inner surface. If there is, it will not specifically limit, A well-known technique can be used.

(Middle axis)
The middle shaft 10 is a member that forms the center line of the screw 3 and rotates the wing portion 9. The middle shaft 10 is hollow and sealed at the upper end, and has a structure in which air stays inside the hollow of the middle shaft 10. Further, the central shaft 10 is not fixed to a casing 13 and a casing 14 described later. The material of the middle shaft 10 is not particularly limited as long as the rotation of the wing portion 9 can be sufficiently realized, and a known technique can be used.

3. Low pressure filtration dewatering section The low pressure filtration dewatering section 4 is a flanged short tubular member for dewatering the sludge P guided in the vertical direction by the screw 3 by low pressure filtration. The low-pressure filtration / dehydration unit 4 mainly includes a low-pressure filtration / dehydration cylinder 11 and a casing 13. In this low pressure filtration and dehydration section 4, the pressure loss through which the desorbed liquid Q passes through the low pressure filtration and dehydration cylinder 11 is maintained at a water column pressure of 10 m or less.

(Low pressure filtration dehydration cylinder)
The low-pressure filtration dewatering cylinder 11 is a member for filtering the sludge P and separating it into the desorbed liquid Q and the dewatered sludge R. Specifically, the sludge P is at a low pressure due to a pressure loss with the casing 13. For filtration and dehydration. The structure of the low pressure filtration dehydration cylinder 11 is not particularly limited as long as it can filter the sludge P and sufficiently separate the desorbed liquid Q, but it is preferable to use a wedge wire screen described later.

(casing)
The casing 13 is a member for storing the low pressure filtration dehydration cylinder 11 and the desorption liquid Q, and specifically, for storing the desorption liquid Q separated from the low pressure filtration dehydration cylinder 11. . The casing 13 is provided with a desorbed liquid discharge unit 15, and the desorbed liquid Q is discharged from the desorbed liquid discharge unit 15 to the outside. The material of the casing 13 is not particularly limited as long as it can protect the low-pressure filtration dewatering cylinder 11 from the outside and can sufficiently store and discharge the desorbed liquid Q, and a known technique can be used.

4). High-pressure filtration dewatering section The high-pressure filtration dewatering section 5 is a flanged short tube member for further dewatering the dewatered sludge R dehydrated by the low-pressure filtration dewatering section 4 by high-pressure filtration. The high pressure filtration dewatering unit 5 mainly includes a high pressure filtration dehydration cylinder 12 and a casing 14. In the high pressure filtration dewatering unit 5, the pressure loss through which the desorbed liquid Q passes through the high pressure filtration dewatering cylinder 12 is maintained at a water column pressure of 10 m or more.

(High pressure filtration dehydration cylinder)
The high pressure filtration dewatering cylinder 12 is a member for further filtering the dewatered sludge R dehydrated by the low pressure filtration dewatering unit 4 to separate the desorbed liquid Q. Specifically, the dewatered sludge R is separated from the casing 14. It is for dehydrating by filtration at high pressure due to the pressure loss between them. The structure of the high pressure filtration dehydration cylinder 12 is not particularly limited as long as it can dehydrate the sludge R and sufficiently separate the desorbed liquid Q, but it is preferable to use a wedge wire screen described later.

(casing)
The casing 14 is a member for storing the high-pressure filtration dehydration cylinder 12 and the desorption liquid Q, and specifically, for storing the desorption liquid Q separated from the high-pressure filtration dehydration cylinder 12. . An opening 16 is disposed in the casing 14, and the desorbed liquid Q and air are discharged from the opening 16 to the outside. That is, the desorbed liquid Q discharged from the high pressure filtration dewatering unit 5 is discharged from the casing 14 in an air released state. The material of the casing 14 is not particularly limited as long as it can protect the high pressure filtration dehydration cylinder 12 from the outside, and can sufficiently store and discharge the desorbed liquid Q and discharge the air, and use a known technique. Can do.

5. Horizontal bearing portion The horizontal bearing portion 6 is a member for supporting the buoyancy caused by the sludge P inside the low-pressure filtration dehydration cylinder 11 and the high-pressure filtration dehydration cylinder 12 and the screw 3 that is lifted by the reaction reaction force of the sludge P. The horizontal bearing 6 is provided with a dewatered sludge discharger 17, and the dewatered sludge R is discharged from the dewatered sludge discharger 17. The material and structure of the horizontal bearing portion 6 are not particularly limited as long as they can sufficiently support the floating screw 3 in the vertical direction, and a known technique can be used.

4). Low Pressure Filtration / Dehydration Unit Differential Pressure Adjustment System The low pressure filtration / dehydration unit differential pressure adjustment system 7 is a member for adjusting the desorbed liquid discharge flow rate from the low pressure filtration / dehydration unit 4. Specifically, the low-pressure filtration / dehydration part differential pressure adjustment system 7 is a member for detecting the pressure loss difference between the low-pressure filtration / dehydration cylinder 11 and the casing 13 and adjusting the discharge flow rate of the desorbed liquid Q. In addition, the low pressure filtration dehydrating unit differential pressure adjustment system 7 includes a flow rate adjustment valve 18, and the discharge flow rate of the desorbed liquid Q is adjusted by the flow rate adjustment valve 18. The means of the low-pressure filtration / dehydration section differential pressure adjustment system 7 is particularly limited as long as it can sufficiently detect the pressure loss difference between the low-pressure filtration / dehydration cylinder 11 and the casing 13 and adjust the discharge flow rate of the desorbed liquid Q. Instead, a known technique can be used. Further, the type and structure of the flow rate control valve 18 are not particularly limited as long as the discharge flow rate of the desorbed liquid Q can be sufficiently adjusted.

5. High pressure filtration dewatering section internal pressure adjustment system The high pressure filtration dewatering section internal pressure adjustment system 8 is a member for adjusting the amount of dewatered sludge discharged from the high pressure filtration dewatering section 5. Specifically, the high pressure filtration dewatering section internal pressure adjustment system 8 is a member for detecting the pressure in the high pressure filtration dewatering cylinder 12 and adjusting the discharge amount of the dewatered sludge R. Further, the high pressure filtration dewatering section internal pressure adjustment system 8 includes a discharge amount adjustment valve 19, and the discharge amount of the dewatered sludge R is adjusted by the discharge amount adjustment valve 19. The means for adjusting the internal pressure of the high-pressure filtration dewatering section 8 is not particularly limited as long as the pressure in the high-pressure filtration dewatering cylinder 12 can be sufficiently detected and the discharge amount of the dewatered sludge R can be adjusted. Can be used. Further, the type and structure of the discharge amount adjusting valve 19 are not particularly limited as long as the discharge amount of the dewatered sludge R can be sufficiently adjusted. Note that the desorbed liquid Q discharged from the high-pressure filtration dehydration unit 5 is discharged from the casing 14 in an air-released state.

<Operation procedure of filtration dehydrator>
Next, the operation procedure of the filtration dehydrator 1 will be described in detail focusing on the effects.

  First, the sludge P is supplied from the sludge supply unit 2, and the sludge P is filled in the low-pressure filtration dewatering cylinder 11 and the high-pressure filtration dewatering cylinder 12. At this time, as the sludge P is filled in the low-pressure filtration dewatering cylinder 11 and the high-pressure filtration dewatering cylinder 12, the screw provided with the hollow shaft and the middle shaft sealed at the upper end and not fixed to the casing 13 and the casing 14 is sludge. It floats due to the buoyancy caused by P and the reaction reaction force of sludge P. The screw 3 that has floated in this manner is naturally supported by the reaction reaction force of the sludge P while being supported in the vertical direction by the horizontal bearing portion 6, and the inner surfaces of the low-pressure filtration dehydration cylinder 11 and the high-pressure filtration dehydration cylinder 12 are effective. And it can be reliably cleaned. In other words, the filtration dehydrator 1 can efficiently and naturally rotate the screw only by the reaction reaction force of the sludge supply without providing a special drive mechanism for rotating the screw. While realizing energy saving, effective achievement of sludge dehydration and prevention of clogging of the filtration surface can be realized, and easy maintenance can be achieved at the same time.

  In particular, while maintaining the pressure loss through which the desorbed liquid Q passes through the low-pressure filtration dehydration cylinder 11 in the low-pressure filtration dehydration section 4 at a water column pressure of 10 m or less, the high-pressure filtration dehydration section 5 removes the high-pressure filtration dehydration cylinder 12 from the desorption liquid. By maintaining the pressure loss through which Q passes at a water column pressure of 10 m or more, the sludge P can be efficiently dehydrated stepwise and separated into the dewatered sludge R and the desorbed liquid Q effectively and reliably. In the low-pressure filtration dehydration unit 4, the internal pressure tends to increase. On the other hand, in the high-pressure filtration dehydration unit 5, the internal pressure tends to decrease. The internal pressure of the low-pressure filtration dewatering unit 4 is kept low by adjusting the desorbed liquid discharge flow rate, and the high-pressure filtration dewatering unit internal pressure adjusting system 8 adjusts the amount of dewatered sludge discharged from the high-pressure filtration dewatering unit 5 to adjust the high-pressure filtration. By maintaining the internal pressure of the dewatering unit 5 high, effective and efficient sludge dewatering can be easily maintained without reducing the sludge dewatering effect.

  Furthermore, the filter medium constituting the low-pressure filtration dehydration cylinder 11 and the high-pressure filtration dehydration cylinder 12 may be a wedge wire screen. In this way, by using the wedge wire screen as the filter material constituting the low pressure filtration dehydration cylinder 11 and the high pressure filtration dehydration cylinder 12, the filtration dehydrator 1 maintains a simple configuration and the size of the entire dehydrator is compact. In addition, the sludge dewatering can be effectively achieved, and the blockage prevention of the inner surfaces of the low pressure filtration dewatering cylinder 11 and the high pressure filtration dewatering cylinder 12 can be further improved.

  The filtration dehydrator of the present invention is not limited to the above embodiment. For example, in the filtration type dehydrator of the present invention, a configuration in which the low pressure filtration dehydration in the low pressure filtration dehydration unit is divided into multiple stages can be employed. By adopting such a configuration, the filtration type dehydrator of the present invention can finely control sludge dehydration with a simple configuration and easy operation according to various conditions such as sludge properties. It becomes possible.

  As described above, the filtration type dehydrator of the present invention can be suitably used for dewatering sludge generated from a sewage treatment facility.

DESCRIPTION OF SYMBOLS 1 Filtration type dehydrator 2 Sludge supply part 3 Screw 4 Low pressure filtration dehydration part 5 High pressure filtration dehydration part 6 Horizontal bearing part 7 Low pressure filtration dehydration part differential pressure regulation system 8 High pressure filtration dehydration part internal pressure regulation system 9 Wing 10 Central shaft 11 Low pressure filtration Dehydration cylinder 12 High pressure filtration dehydration cylinder 13 Casing 14 Casing 15 Desorbed liquid discharge part 16 Opening part 17 Dehydrated sludge discharge part 18 Flow control valve 19 Discharge control valve P Sludge Q Desorbed liquid R Dehydrated sludge

Claims (3)

A sludge supply section for supplying sludge;
A filtration dewatering cylinder for filtering this sludge and separating it into dewatered sludge and desorbed liquid,
A casing for storing the filtration dewatering cylinder and the desorption liquid;
A vertical filtration dehydrator that is housed in the filtration dehydration cylinder and includes a screw having a central shaft and a wing portion;
The middle shaft is hollow and the upper end is sealed, and is not fixed to the casing,
A horizontal bearing portion for supporting the buoyancy caused by the sludge in the filtration dewatering cylinder and the screw that floats by the reaction reaction force of the sludge;
A filtration type dehydrator, wherein the inner surface of the filtration dehydration cylinder is cleaned by a blade portion of a screw that is rotated by a reaction force of the sludge conveyance by the sludge supply unit. The filtration dewatering cylinder and the casing are
A low pressure filtration and dehydration unit for maintaining the pressure loss through which the desorbed liquid passes through the filtration and dehydration cylinder at a water column pressure of 10 m or less;
Divided into a high pressure filtration dehydration unit for maintaining the pressure loss through which the desorbed liquid passes through the filtration dehydration cylinder at a water column pressure of 10 m or more,
A low-pressure filtration dewatering unit differential pressure adjustment system for adjusting a desorbed liquid discharge flow rate from the low-pressure filtration dehydration unit;
The filtration type dehydrator according to claim 1, further comprising: a high pressure filtration dewatering unit internal pressure adjustment system for adjusting a dewatered sludge discharge amount from the high pressure filtration dehydration unit. The filtration type dehydrator according to claim 1 or 2, wherein the filtration material constituting the filtration dewatering cylinder is a wedge wire screen.

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