JP2004337752A - Screw type filtering dehydrator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a screw type filtering dehydrator of which the filter body is quickly and easily assembled or disassembled, which is manufactured at a low cost and is excellent in maintenance, and which prevents an annular movable plate from receiving the effect of gravity to excessively fall to a necessary degree or more at the time of eccentric rotary motion due to a screw conveyor and does not cause an increase in the load to a motor. <P>SOLUTION: This screw type filtering dehydrator, in which the annular movable plates 9 interposed among respective laminating layers of a large number of annular filter plates 8 in a filter frame 1 are eccentrically rotated by the screw conveyor 11, has abutting surfaces 5 extending in an axial direction on the inner peripheral surface of the filter frame 1, hooking edges 14 mutually abutting against the abutting surfaces 5 on respective annular filter plates 8, and also a crosspiece-shaped remaining part 6 facing to the outer peripheral lower side of a filter body 7 on the inner peripheral surface of the lower side of the filter frame 1. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention provides, for example, a screw-type filtration dewatering method for separating a suspension containing suspended fine particles generated in a relatively small-scale sewage treatment operation represented by an oxidation ditch method into a filtrate and suspended fine particles. It concerns the device.
[0002]
[Prior art]
A plurality of annular filtration plates are stacked at a predetermined interval from each other in a cylindrical filtration frame having a transparent window on the peripheral surface with one end serving as a sludge inlet and the other end serving as a dewatering cake outlet. The annular movable plate is loosely fitted between the laminations of the annular filtration plates to form a cylindrical filter body having a gap between the plates as a drainage drainage groove, and a center hole of the filter body is formed. 2. Description of the Related Art A screw-type filtration and dewatering apparatus that eccentrically rotates each annular movable plate by driving a screw conveyor fitted in a filter is known. In order to maintain the formation of the filter body, generally, holes for bolt insertion are formed in ears protruding from a plurality of locations around each annular filter plate, and a short tubular spacer is interposed. A rotation preventing structure is adopted in which a through bolt is inserted into a hole in an ear of each plate, and an end of the through bolt is screwed with a nut (for example, see Patent Documents 1-2). Further, as an alternative rotation preventing structure, a method of driving a long key into a fitting surface of a filter body in a filter frame has been proposed (for example, see Patent Document 3).
[0003]
[Patent Document 1]
JP-A-2000-288598 (FIG. 1-4)
[Patent Document 2]
JP 2001-224913 A (FIG. 1-12)
[Patent Document 3]
Japanese Patent Application No. 2003-48579 (Fig. 3-8)
[0004]
[Problems to be solved by the invention]
In the structures of Patent Literatures 1 and 2, a large number of annular filtration plates and short tubular spacers must be inserted one by one into a plurality of through bolts at the time of assembling the filter body, which consumes a great deal of time and labor. As a result, the workability of assembling is poor and the production cost increases. In this type of apparatus that treats sludge, maintenance work involving disassembly of the filter body is often required due to replacement of a worn plate, and the like. The bolts must be extracted from each annular filter plate and the short tubular spacer, and after disassembly, the filter must be assembled again in the above-described procedure.
[0005]
Further, in the non-rotating structure using a key disclosed in Patent Document 3, the contact surfaces between the key and the filter frame and between the key and the annular filter plate are extremely small, and unless the inner peripheral surface of the filter frame is finished with high precision, Rattle occurs, and the effect of preventing the rotation of the annular filter plate in the filter frame becomes insufficient. A cylindrical filter frame as disclosed in Patent Documents 1 to 3 is obtained by bending a metal plate into a cylindrical shape by roll bending, welding the abutting portion, and cutting the inner peripheral surface of the cylinder to a predetermined inner diameter. Due to the finished dimensions, the production costs are high. However, as described above, in order to rely on the key to prevent the rotation of the annular filtration plate in the filtration frame, it is indispensable that the inner peripheral surface of the filtration frame is finished with high accuracy.
[0006]
Furthermore, as an operating characteristic of the annular movable plate, particularly at a point where the soft sludge is conveyed near the inlet, the eccentric rotation in the downward direction of the plate is affected by gravity, and depending on the rotation position of the screw blade, the annular movable plate is rotated. Will fall more than necessary. Then, when the annular movable plate turns in the ascending direction from the lowered position, the amount of sliding contact with the annular filter plate increases, the frictional resistance increases, and the torque load for pushing the annular movable plate upward increases more than usual. This significantly increases the load on the prime mover driving the screw conveyor. The above-mentioned disadvantages are the same in the devices of Patent Documents 1 and 2.
[0007]
A first object of the present invention is to provide a screw that can be manufactured at low cost and has excellent maintainability, without requiring a cutting process inside a filter frame, and assembling and disassembling of a filter body can be performed quickly and easily. An object of the present invention is to provide a filtration dewatering apparatus. Further, a second object of the present invention is to prevent the annular movable plate from being excessively lowered under the influence of gravity during the eccentric rotation by the screw conveyor, thereby increasing the load on the prime mover. There is no screw type filtration dewatering apparatus.
[0008]
[Means to solve the problem]
In the screw-type filtration and dehydration apparatus according to the present invention, a number of annular filtration plates are placed in a filtration frame having one end provided as a sludge feed port and the other end provided as a dehydrated cake feed port and having a transparent window provided on the peripheral surface. Arranged in a laminating manner at a predetermined interval from each other, and a ring-shaped movable plate is loosely fitted between the laminations of the ring-shaped filtration plate to form a filter between the plates as a drainage drainage groove. The screw conveyor formed with the outer diameter of the screw blade larger than the inner diameter of the annular movable plate and smaller than the inner diameter of the annular filtration plate is fitted into the center hole of the filter body, and the screw blade is driven when the screw conveyor is driven. The outer peripheral edge slides on the inner peripheral edge of each annular movable plate to actuate radial eccentric rotational movement on each annular movable plate, and each annular filter plate has an annular outer periphery on its outer periphery. A portion protruding outward from the outer eccentric rotation trajectory of the plate, and a space keeping projection for regulating a gap between the annular filtration plates is attached to the portion, and an inner peripheral surface of the filtration frame is provided. Has an abutment surface that protrudes outward or bends inward and extends in the axial direction, and a retaining edge formed in a protruding or bent shape so as to be in contact with the corresponding surface in each annular filter plate. Then, each of the annular filtration plates is prevented from rotating by locking the locking edge to the contact surface.
[0009]
Further, in the invention according to claim 2, on the premise of the screw-type filtration dewatering device according to claim 1, a support member extending in the axial direction on the lower inner peripheral surface of the filter frame facing the outer peripheral lower side of the filter body is provided. The ring-shaped movable plate is held, and the amount of eccentricity of the annular movable plate in the downward direction is regulated.
[0010]
DESCRIPTION OF THE PREFERRED EMBODIMENTS
This will be described below with reference to the embodiment shown in FIGS.
[0011]
Reference numeral 1 denotes a filter frame made of a metal plate having one end provided with a sludge feed port 2 and the other end provided with a dewatered cake feed port 3 and transparent windows 4,... The upper frame member 1A and the lower frame member 1B are joined from above and below, and the joined portions are welded and joined together, and the inner peripheral surface projects outward or bends inward to extend in the axial direction. 5 are held, and furthermore, the lower inner peripheral surface is provided with an axially extending retaining portion 6 which extends in the axial direction.
[0012]
Reference numeral 7 denotes a cylindrical filter body, in which a large number of annular filter plates 8,... 8 are arranged in a stack at a predetermined interval in the filter frame 1, and the annular filter plates 8,. The annular movable plates 9,... 9 are loosely fitted between the respective laminations to form gaps between the plates in the drainage outflow grooves 10,. Reference numeral 11 denotes a screw conveyor fitted in the center hole 7H of the filter body 7, wherein the outer diameter of the screw blade 11B is larger than the inner diameter of the annular movable plates 9, 9 and smaller than the inner diameter of the annular filter plates 8,. When the screw conveyor 11 is driven, the outer peripheral edge of the screw blade 11B slides on the inner peripheral edge of each of the annular movable plates 9 to cause eccentric rotational movement in the radial direction. Act to cause The outer periphery of each of the annular filtration plates 8,... 8 has a portion that protrudes outward from the outer eccentric rotation trajectory of each of the annular movable plates 9,. The gaps between the annular filtration plates 8,... 8 are regulated to be slightly larger than the thicknesses of the respective annular movable plates 9,. .. 14 are retaining edges held by each of the annular filtration plates 8,..., And are formed in a protruding or bent shape so as to be in contact with the contact surfaces 5. The locking edges 14,... 14 are locked to the contact surfaces 5,. Reference numeral 15 denotes a fixed body for holding the formed state of the filter 7, which is detachably fixed to the frame end of the filter frame 1. Reference numeral 16 denotes a motor for driving the screw conveyor 11, and reference numeral 17 denotes a discharge pressure adjusting valve attached to the delivery port 3.
When the prime mover 16 is driven, the screw conveyor 11 rotates, and the outer peripheral edge of the screw blade 11B slides obliquely to the inner peripheral edge of each of the annular movable plates 9 to generate an eccentric rotational motion. In the process in which the sludge sent into the filter body 7 advances in the axial direction while rotating along the screw blade 11B, the filtered filtrate passes through the drainage outflow grooves 10... 10 and the transparent windows 4. The dewatered cake that has flowed down and has been dewatered to have a low water content is sequentially discharged from the front delivery port 3.
[0014]
The above-described eccentric rotation is performed to prevent clogging of the drainage outflow grooves 10,..., But excessive eccentricity causes the following adverse effects. Many dewatering devices of this type are set so that the amount of upward eccentricity is generally appropriate. There is no problem in the upward eccentricity, since the eccentric action is forcibly performed in a state where the outer peripheral edge of the screw blade 11B is obliquely slidingly contacting the inner peripheral edge of the annular movable plate 9. However, since the downward eccentric action is performed in a state where the sliding contact with the screw blade 11B is released, the eccentric action is affected by gravity. Conventionally, depending on the rotational position of the screw blade 11B, as shown in FIG. 9 may fall unnecessarily, resulting in an excessively eccentric state in which a large crescent crescent-shaped gap g is formed between the inner peripheral lower edge of the annular filtration plate 8 and the outer peripheral edge of the annular movable plate 9. The annular movable plate 8 in the excessively eccentric state sometimes receives an abnormally large force in the direction of the discharge port from the screw blade 11B, and the frictional force with the annular filter plate 8 increases to be in a locked state, thereby causing a load on the prime mover. Not only increases but also may lead to plate breakage and damage to the screw blade 11B.
[0015]
Unlike the conventional structure shown in FIG. 8, as shown in FIGS. 1 to 6, an axially extending support member 6 is provided on the lower inner peripheral surface of the filter frame 1 opposed to the outer peripheral lower portion of the filter body 7. If this is done, the amount of eccentricity of the annular movable plate 9 in the downward direction is regulated by the stay-shaped retaining portion 6.
[0016]
【The invention's effect】
According to the present invention, assembling and disassembly of the filter body are performed quickly and easily unlike the conventional method using through bolts. Since the contact surface is formed larger than that, there is no need to perform high-precision cutting on the inside of the filtration frame, and there is an advantage that a sufficient detent effect can be obtained. It can be manufactured at low cost and has excellent maintainability. Further, a screw-type filtration dewatering apparatus can be provided. Furthermore, according to the screw-type filtration and dewatering apparatus of the present invention, in the eccentric rotation of the annular movable plate accompanying the driving of the screw conveyor, excessive downward eccentricity of the annular movable plate due to the influence of gravity is prevented, and the plate and the screw There is an advantage that damage to the blades can be prevented and no increase in the load on the prime mover occurs.
[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 the device of the present invention.
FIG. 3 is a vertical sectional front view of the device of the present invention.
FIG. 4 is a side view of a filtration frame in the apparatus of the present invention.
FIG. 5 is a vertical sectional front view of a filtration frame in the apparatus of the present invention.
FIG. 6 is a vertical sectional side view of an upper frame member and a lower frame member constituting a filtration frame in the apparatus of the present invention.
FIG. 7 is a front view of an annular filtration plate in the apparatus of the present invention.
FIG. 8 is a longitudinal sectional front view of the conventional device, showing a state where the annular movable plate is excessively eccentric downward.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Filtration frame 2 Inlet 3 Outlet 4 Transmissive window 5 Contact surface 6 Retaining part 7 Filtration body 7H Center hole 8 Annular filtration plate 9 Annular movable plate 10 Filtration outflow groove 11 Screw conveyor 11B Screw blade 12 Overhanging part 13 Spacing 14 for retaining edge

Claims (2)

A large number of annular filtration plates are arranged in a stack at a predetermined interval from each other in a filtration frame having a transparent window on the peripheral surface with one end serving as a sludge inlet and the other end serving as a dewatering cake outlet. The annular movable plate is loosely fitted between the laminations of the annular filtration plate to form a cylindrical filter body having a slit between each plate as a drainage drainage groove, and the outer diameter of the screw blade is set to the annular movable plate. A screw conveyor formed to be larger than the inner diameter of the annular filtration plate and 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 to the inner peripheral edge of each annular movable plate. Acts so as to generate radial eccentric rotational motion on each annular movable plate in contact with it, and protrudes outward from the outer eccentric rotational trajectory of each annular movable plate on the outer periphery of each annular filter plate. The filter frame is provided with a spacing projection that regulates the gap between the respective annular filtration plates, and the filter frame has an inner peripheral surface protruding outward or inwardly bending. Each of the annular filter plates has a contact surface extending in the direction, and a retaining edge formed in a protruding or bent shape so as to be in contact with the corresponding surface, and the retaining edge is retained on the contact surface. A screw-type filtration dewatering device, wherein each of the annular filtration plates is prevented from rotating. A ridge-shaped retaining portion extending in the axial direction is held on the lower inner peripheral surface of the filtration frame facing the outer peripheral lower portion of the filter, and the downward eccentric amount of the annular movable plate is regulated by the ridge-shaped retaining portion. The screw type filtration dewatering apparatus according to claim 1, wherein the apparatus is configured as described above.

Images