JP3781253B2 - Disc filter filter media - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a filter medium for a filter of difficult-to-filter sludge such as sewage sludge, and particularly to an improvement of a filter medium of a disk filter having an impeller disposed in a filter chamber.
[0002]
[Prior art]
Conventionally, as a filter medium of a disk filter, a thin punching metal having a hole having a diameter of 0.25 mm to 0.5 mm is attached in a disk frame in which a cutout plate is reinforced. Further, as a filter medium used in a dehydrator, for example, as described in JP-A-6-233906, a filter wire having a flat surface and a constant cross section is fixed to a non-square plate-like body, Filter media having a large number of straight slits are known. Further, as described in JP-A-6-210114, a wedge wire screen is also well known in which wedge wires are arranged in parallel and a continuous slit having a V-shaped opening is formed between the wires.
[0003]
[Problems to be solved by the invention]
However, in such a conventional metal filter medium, when concentrated sludge such as sewage sludge is condensed with a polymer and filtered, some solid matter that has come out of the hole in the filter medium remains in the reinforcing disk frame, and the filtrate The flow became worse, the filtration was hindered, and the frequency of washing the filter media was increased. Moreover, in such a metal filter medium, high pressure cannot be applied due to insufficient strength, and when squeezing sludge containing inorganic matter, it is worn out and damaged immediately. In addition, there has been a problem that replacing the filter medium in the case of breakage requires a lot of labor and time.
[0004]
[Means for Solving the Problems]
The present invention aims to solve the above-mentioned problem, and forms a filtration chamber with two disc-shaped filter plates, an outer ring and a pair of inner ring support cylinders, and supports the inner ring. A support cylinder is connected to the cylinder, a drive shaft is inserted into the support cylinder, a supply path for the stock solution is provided inside the drive shaft, and a plurality of supply ports are opened on the peripheral surface of the drive shaft, and a filtration chamber together to communicate with the, disposed a rotatable impeller filtration chamber, wherein in the filtration machine for press-fitting supplying stock to the filtering chamber, the filter plate is joined integrally an annular support frame having a wedge wire screen and the radial rib This is a metal disk filter material. The wedge wire screen is composed of wedge wires arranged in parallel horizontally and support rods arranged in parallel in the vertical direction for fixing the wedge wires, and the opening of the wedge wire screen is provided in the range of 100 μm to 200 μm. is there.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
The filter medium of the disk filter according to the present invention is configured as described above, and the strength is increased by joining and integrating the wedge plate and the annular support frame having the radial ribs to the filter plate forming the filter chamber. There is no breakage against high pressure and a cake with a low water content can be obtained. And attachment of a filter medium becomes easy and it is convenient on maintenance. In addition, the wedge wire screen has the wedge wires arranged in parallel horizontally and the support rods fixing the wedge wires arranged in parallel in the vertical direction, so that there is less accumulation of filtrate and some solid matter, and the frequency of washing the filter media can be reduced. .
[0006]
【Example】
The filter medium of the disk filter according to the present invention will be described in detail with reference to the drawings. First, in FIGS. 1 and 2, reference numeral 1 is a filter plate made of a pair of metal disk filter media. A wedge wire screen 4 in which a large number of support rods 3 are fixed in the longitudinal direction from the back surface and a circular support frame 6 having radial ribs 5 are joined and integrated with a large number of parallel wedge wires 2. The solid matter that has gotten through with the filtrate in the lateral slits of the wedge wire 2 is washed away with the filtrate that flows down along the longitudinal slits of the support rod 3 on the back side. There is no accumulation of filtrate and solid matter in the eyes, and the frequency of filter media washing is reduced. As shown in FIG. 3, the pair of filter plates 1, 1 has an outer peripheral end connected to the outer ring 7, and an inner peripheral outer wall connected to the pair of inner ring support cylinders 8, 8. The chamber 9 is configured to facilitate the attachment and removal of the filter plate 1.
[0007]
A support cylinder 10 is connected to the inner ring support cylinder 8, and as shown in FIG. 4, the support cylinders 10 and 10 before and after the filtration chamber 9 are supported on the frames 12 and 12 via bearings 11 and 11. is there. A drive shaft 13 is inserted into the support cylinder 10, and a drive pulley 14 fitted to one end of the drive shaft 13 is linked to the drive machine 15. In addition, a supply path 16 for the stock solution is provided inside the drive shaft 13, and a plurality of supply ports 17 that communicate with the filtration chamber 9 are opened on the peripheral surface of the drive shaft 13. A stock solution supply chamber 18 surrounded by the inner ring support cylinder 8 and the support cylinder 10 is formed between the filtration chamber 9 and the drive shaft 13. An undiluted solution supply pipe 20 is connected to one end of the drive shaft 13 via a universal joint 19. The supply pipe 20 is connected to a sludge tank 22 via a supply pump 21, and is stored in the sludge tank 22. A certain sludge is caused to flow into the stock solution supply chamber 18 from the plurality of supply ports 17 of the drive shaft 13, and the sludge is uniformly pressed into the filtration chamber 9 from the stock solution supply chamber 18.
[0008]
As shown in FIGS. 3 and 5, the filter chamber 9 has an impeller 23 supported on a drive shaft 13 inserted into the support cylinder 10, and the side edge of the impeller 23 is brought close to the filter plate 1. The tip is retracted backward in the rotational direction. The impeller 23 is rotated in the filtration chamber 9 by operating the driving machine 15. In the embodiment of the present invention, the blades 23a of the impeller 23 are bent into four straight pieces to approximate a curved line, and the impeller 23 having six blades is arranged in the filtration chamber 9. It is set up. In this manner, if the blade 23a is bent into a straight piece and approximated to a curved line, the manufacture becomes easy. A reinforcing plate 24 is fixed to the blade 23a on the rear side in the rotational direction of the impeller 23 along the center of the blade surface. The reinforcing plate 24 is a reinforcing rib disposed on the rear surface in the rotational direction of the blade 23a so that its height gradually decreases from the boss 23b side toward the tip of the blade 23a. It is a shape that can hold down to a minimum.
[0009]
As shown in FIG. 6, a cake outlet 25 is provided on the outer peripheral ring 7 in the peripheral portion of the filtration chamber 9. A back pressure adjusting valve 26 disposed in the outlet 25 is operated by operating a cylinder 27. A back pressure is applied to the filtration chamber 9. Reference numeral 28 denotes a cake chute provided at the outlet 25, reference numeral 29 denotes a filtrate receiving trough, reference numeral 30 denotes a cleaning pipe of the filter plate 1, and reference numeral 31 denotes a cover for preventing scattering of cleaning water and the like.
[0010]
The apparatus according to the present invention is configured as described above, and the opening of the wedge wire screen 4 of the filter plate 1 is set in the range of 100 μm to 200 μm, and the impeller 23 is set at 0.1 to 1.0 rpm. When sludge is supplied from the supply path 16 of the drive shaft 13 to the central portion of the filtration chamber 9 with a press-fitting pressure of 0.1 to 0.7 Kg / cm 2 while rotating at a low speed, the sludge pushing pressure and the impeller 23 are rotated. Under pressure, it is conveyed under pressure toward the outer periphery, and moisture is separated by the wedge wire screens 4 of the left and right filter plates 1. In the vicinity of the axial center immediately after the press-fitting, sludge is concentrated mainly by the press-fitting pressure, and the impeller 23 presses the sludge with a force that overcomes the sliding frictional resistance force between the concentrated sludge and the filter plate 1, and the sludge is press-fitted. A shearing action is applied to the cake that is curved and moved by the pressure and the rotational action force of the blades 23a. The dehydrated cake can be taken out while applying back pressure by the back pressure adjusting valve 26 of the outlet 25, and the side surface of the blade 23a of the impeller 23 rotates close to the inner surface of the filter plate 1, so that the filter plate 1 Can be continuously operated without clogging. The results of the dehydration test with the sewage mixed raw sludge agglomerated with polymer (solids concentration 1.59% W / V) were as good as 78.7% cake moisture content and 98.1% SS recovery rate. . That is, if the opening of the wedge wire screen 4 is set in the range of 100 μm to 200 μm based on the pressure of the stock solution and the rotational speed of the impeller, a cake having a low water content and a filtrate having a low solid content can be obtained. Is.
[0011]
【The invention's effect】
As is apparent from the above description, the filter medium of the disk filter according to the present invention is configured as described above, and the filter plate is a metal disk in which the wedge wire screen and the annular support frame having radial ribs are joined and integrated. Since it is used as a filter medium, the strength is increased, and there is no damage against high pressure, and the filter plate can be easily attached and detached. The wedge wire screen is composed of wedge wires arranged in parallel horizontally and support rods arranged in parallel in the vertical direction to fix the wedge wires. Since the solid matter is washed away with the filtrate flowing down along the slits of the support rod on the back side, there is no accumulation of filtrate and solid matter in the slit eyes, and the frequency of washing the filter medium is also reduced.
[Brief description of the drawings]
FIG. 1 is a front view of a wedge wire screen.
FIG. 2 is a rear view of a filter plate in which a wedge wire screen is fitted in an annular support frame.
FIG. 3 is a longitudinal sectional side view of a main part in which a filtration chamber according to the present invention is held on a drive shaft.
FIG. 4 is a vertical side view of a disk filter using the filter medium according to the present invention.
FIG. 5 is a front view of an impeller disposed in a disk filter.
FIG. 6 is a longitudinal front view of a disk filter using a filter medium according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Filter plate 2 Wedge wire 3 Support rod 4 Wedge wire screen 5 Radial rib 6 Ring support frame 7 Outer ring 9 Filtration chamber 23 Impeller

Claims (3)

A filter chamber (9) is formed by two disk-shaped filter plates (1, 1), an outer ring (7), and a pair of inner ring support cylinders (8, 8), and the inner ring support cylinder (8). Is connected to a support cylinder (10), a drive shaft (13) is inserted into the support cylinder (10), a stock solution supply path (16) is provided inside the drive shaft (13), and the drive shaft ( 13) A plurality of supply ports (17...) Are opened on the peripheral surface to communicate with the filtration chamber (9), and a rotatable impeller (23) is disposed in the filtration chamber (9). in the filtration machine for press-fitting supplying stock to the chamber (9), the filter plates (1) are wedge wire screen (4) and the metal disc filter medium was integrally bonded to the annular support frame having radial ribs (5) (6) A filter medium for a disk filter characterized by comprising:   The wedge wire screen (4) comprises a wedge wire (2) arranged in parallel horizontally and a support rod (3) arranged in parallel in a vertical direction for fixing the wedge wire (2). The filter medium of the described disk filter.   The filter medium of the disk filter according to claim 1 or 2, wherein the opening of the wedge wire screen (4) is in the range of 100 µm to 200 µm.

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