JP2004066146A - Screw type filtration/dehydration apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a screw type filtration/dehydration apparatus which can perform effective and proper filtration/dehydration work by restraining the leakage of sludge in the vicinities of a feed port and a discharge port and improving the filtrate discharging efficiency in the intermediate position of a filter body. <P>SOLUTION: In this screw type filtration/dehydration apparatus, a large number of circular filter plates 2 and circular movable plates 3 are stacked alternately in a cylindrical form while leaving a narrow gap between the adjacent plates 2 and 3 to prepare the filter body 1 using the narrow gap as a filtrate discharging groove 4. A screw conveyer 11 is inserted into the central hole of the body 1. The inner diameter V' of the plate 3B in the intermediate position 1B of the body 1 is made smaller than inner diameter V of the plate 3A in the vicinity 1A of the feed port and inner diameter V of the plate 3C in the vicinity 1C of the discharge port. When the conveyer 11 is driven, the eccentric rotation momentum of the plate 3B is made larger than those of the plates 3A and 3C. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention, for example, a suspension containing suspended fine particles generated in a relatively small-scale sewage treatment work represented by the oxidation ditch method and the like, by a low concentration state without passing through the concentration step, the suspension with the filtrate The present invention relates to a screw-type filtration dewatering apparatus for separating fine particles into fine particles.
[0002]
[Prior art and its problems]
Conventionally, a large number of annular filtration plates are fixed in a stacked manner with a small gap therebetween, and each of the small gaps is separated by a loosely fitted annular movable plate between the respective annular filtration plates to form a separation water outflow groove. The outer diameter of the screw blade is larger than the inner diameter of the annular movable plate, with the opening at the beginning end of the filtration body as the inlet for solid-liquid and the opening at the end as the outlet for dehydrated solids. A screw conveyor formed smaller than the inner diameter of the annular filtration plate is fitted into the center hole of the filter body, and when the screw conveyor is driven, the outer peripheral edge of the screw blade slides against the inner peripheral edge of each annular movable plate and moves radially. A screw-type filtration dewatering device that causes the eccentric rotational movement of each annular movable plate to occur is known.
[0003]
By driving the screw conveyor, the annular movable plate performs eccentric rotational movement along the gap between the annular filtration plates, and the sludge raw water sent into the filter body from the inlet port advances forward in the axial direction while turning along the screw blade In the process of filtration, the filtered water flows out of the separation water outlet groove and is dewatered, and the dewatered sludge cake having a reduced water content is sequentially discharged from the front discharge port, but the dewatering efficiency is improved. Therefore, if the amount of eccentric rotation of the annular movable plate is increased, the amount of sludge leakage near the inlet and the outlet is increased, and the amount of eccentric rotation of the annular movable plate is reduced in order to suppress the leakage of sludge. At present, it is unavoidable that the dehydration efficiency is reduced.
[0004]
[Object of the invention]
SUMMARY OF THE INVENTION An object of the present invention is to provide a screw-type filtration and dewatering apparatus capable of performing effective and appropriate filtration and dehydration operations by suppressing leakage of sludge in the vicinity of an inlet and an outlet and increasing drainage efficiency of drainage in an intermediate portion. More specifically, in the low concentration stage near the feed port, the annular movable plate has a small eccentric rotational movement to prevent the destruction and leakage of sludge flocs, and a large eccentricity of the annular movable plate in the middle portion of the filter body to improve dewatering efficiency. Rotational motion applies a shearing force to the sludge cake to discharge a large amount of liquid, and in the vicinity of the discharge port where the internal pressure is increasing, the annular movable plate suppresses the leakage of sludge by small eccentric rotational motion. It is an object of the present invention to provide a screw-type filtration and dehydration apparatus in which an effective and appropriate filtration and dehydration operation is performed by a simple operation method.
[0005]
Configuration of the Invention
In the present invention, a large number of annular filtration plates are fixed in a stacked manner with a gap therebetween, and each of the annular filtration plates is loosely fitted between the annular filtration plates to separate each of the slits from the separated water outflow grooves. The outer diameter of the screw blade is larger than the inner diameter of the annular movable plate, with the opening at the beginning end of the filtration body as the inlet for solid-liquid and the opening at the end as the outlet for dehydrated solids. A screw conveyor formed to be larger than the inner diameter of the annular filtration plate is fitted into the center hole of the filter body, and when the screw conveyor is driven, the outer peripheral edge of the screw blade slides against the inner peripheral edge of each annular movable plate to be in the radial direction. In the screw-type filtration dewatering device that causes eccentric rotational movement to each annular movable plate, the inner diameter of the annular movable plate at the intermediate portion of the filter body is The eccentric rotational momentum in the radial direction of the annular movable plate at the time of driving the screw conveyor is larger than the inner diameter of the annular movable plate in the vicinity of the mouth and the delivery port. It was configured to be small in the vicinity.
[0006]
[Action]
When the screw conveyor is driven, the outer peripheral edge of the screw blade slides against the inner peripheral edge of each annular movable plate, causing radially eccentric rotational movement of each annular movable plate. And in the process where the sludge raw water sent into the filter body from the inlet port is advanced in the axial direction while turning along the screw blade, the filtered filtrate flows out from the separation water outlet groove and is dewatered and dewatered. The lowered dewatered sludge cake is sequentially discharged from the front discharge port, but the eccentric rotational momentum of the annular movable plate acts large in the middle portion of the filter and small in the vicinity of the feed port and the discharge port. . Therefore, the destruction and leakage of sludge floc in the low concentration stage near the inlet are suppressed, and in the middle part where the dewatering efficiency is to be increased, a large amount of liquid is discharged by applying a shearing force to the sludge cake to increase the internal pressure. In the vicinity of the discharge port, the amount of sludge leak is suppressed.
[0007]
【Example】
This will be described with reference to the following practical examples shown in FIGS.
[0008]
Reference numeral 1 denotes a cylindrical filter, which fixes a large number of annular filtration plates 2... 2 in a laminated state while maintaining a required gap, and annularly separates each of the annular filtration plates 2. 3 are loosely fitted to each other to form separated water outflow grooves 4... 4, and the outer periphery of each annular movable plate 3. The seats 5... 5 protruding outward from the rotation trajectory are provided, and the gaps 6. 6 attached to the seats 5. Is set to be slightly larger than the thickness of each of the annular movable plates 3. 7, 7 are fixed bodies that support the respective seat portions 5,..., And are mounted along the outside of the filter body 1 in a non-contact state with the respective annular movable plates 3,. The opening at the beginning of the filter 1 is a feed port 8 for solid and liquid, the opening at the end is a feed port 9 for dehydrated solids, and a screw conveyor 11 is fitted in the center hole 10. Reference numeral 12 denotes a motor for driving the screw conveyor 11, and reference numeral 13 denotes a discharge pressure adjusting valve attached to the delivery port 9. The screw conveyor 11 is formed such that the outer diameter M of the screw blade 11B is larger than the inner diameter V of each annular movable plate 3,... And smaller than the inner diameter W of each annular filtration plate 2,. The inner diameter V ′ of the annular movable plates 3B 3B in the filter intermediate unit 1B is smaller than the inner diameter V of the annular movable plates 3A 3A near the inlet 1A and the annular movable plates 3C 3C near the outlet 1C. , The eccentric rotational momentum of the annular movable plates 3A,... 3A in the vicinity of the feed port 1A when the screw conveyor 11 is driven becomes small, and the eccentric rotational momentum of the annular movable plates 3B,. The eccentric rotational momentum of the annular movable plates 3C in the vicinity 1C of the delivery port is reduced.
[0009]
When the prime mover 12 is driven, the screw conveyor 11 rotates, and in the process in which the raw sewage fed into the filter body 1 from the feed port 8 advances in the axial direction while rotating along the screw blade 11B, the filtered filtration is performed. The dewatered sludge cake, which flows out of the separated water outflow grooves 4 and is dewatered and has a low water content, is sequentially discharged from the front discharge port 9. In the concentration stage, the eccentric rotational momentum of the annular movable plates 3A... 3A is reduced to prevent the destruction and leakage of the sludge floc, and the eccentricity of the annular movable plates 3B. As the rotational momentum increases, a large amount of liquid is discharged by applying a shearing force to the sludge cake. It will prevent leakage of sludge eccentric rotation of the movable plate 3C · · 3C is decreased.
[0010]
【The invention's effect】
According to the screw filtration dewatering device of the present invention, in the low concentration stage near the feed port, the annular movable plate prevents the sludge flocks from breaking and leaking due to small eccentric rotational movement, and the annular portion in the middle of the filter body where the dewatering efficiency should be increased. The large eccentric rotation of the movable plate applies a shearing force to the sludge cake to discharge a large amount of liquid, and the annular movable plate suppresses the leakage of sludge by the small eccentric rotation near the discharge port where the internal pressure is increasing. That is, an effective and appropriate filtration and dewatering operation is performed by an extremely rational operation method.
[Brief description of the drawings]
FIG. 1 is a vertical sectional side view schematically showing the configuration of a screw-type filtration and dewatering apparatus to which the present invention is applied.
FIG. 2 is a vertical sectional side view of a main part of a filter in the apparatus of the present invention.
FIG. 3 is a vertical cross-sectional front view in the vicinity of an inlet of a filter in the apparatus of the present invention.
FIG. 4 is a vertical sectional front view of an intermediate portion of a filter body in the apparatus of the present invention.
FIG. 5 is a vertical sectional front view in the vicinity of a delivery port in the apparatus of the present invention.
FIG. 6 is a vertical sectional front view of a screw conveyor in the apparatus of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Cylindrical filter body 1A Near inlet 1B Filter intermediate part 1C Near outlet 2 Annular filtration plate 3 Annular movable plate 3A Annular movable plate 3B near inlet The annular movable plate 3C in the intermediate part of filter Annular near outlet Movable plate 4 Separated water outflow groove 8 Solid-liquid inlet 9 Dewatered solids outlet 10 Center hole 11 of filter body Screw conveyor 11B Screw blade M Outer diameter V of screw blade Inner diameter V of annular movable plate Middle part of filter body Inner diameter of annular movable plate W at inner diameter of annular filter plate

Claims (1)

A plurality of annular filtration plates are fixed in a stacked manner with a gap between each other, and each of the annular filtration plates is loosely fitted with an annular movable plate between the respective annular filtration plates, thereby forming each of the slits as a separation water outflow groove. The outer diameter of the screw blade is larger than the inner diameter of the annular movable plate, and the outer opening of the screw blade is larger than the inner diameter of the annular movable plate. A screw conveyor formed to be smaller than the inner diameter of the filter body is fitted in the center hole of the filter, and when the screw conveyor is driven, the outer peripheral edge of the screw blade slides against the inner peripheral edge of each annular movable plate to eccentrically rotate in the radial direction. In a screw-type filtration dewatering device that causes a motion to occur in each annular movable plate, the inner diameter of the annular movable plate at an intermediate portion of the filter body is determined by a feed port and a feed port. It is formed smaller than the inner diameter of the annular movable plate in the vicinity of the outlet, and the eccentric rotational momentum in the radial direction of the annular movable plate at the time of driving the screw conveyor is increased in the middle part of the filter, and in the vicinity of the inlet and the outlet. A screw-type filtration dewatering apparatus characterized by being configured to be small.

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