JPS61153110A - Method for fixing filter plate of filtration and concentration apparatus - Google Patents

Abstract

PURPOSE:To absorb the deformation of a filter plate due to swelling by interposing an elastic member between the filter plate and a fixing frame, and attaching both end parts of the member to the filter plate and the fixing frame when the filter plate is attached to the fixing frame. CONSTITUTION:A fixing frame of fixing a filter plate 2 is formed with plates 18 and 18a, one end is inserted between filter cloths 4 and 4a by using a rubber sheet 19, the other end is inserted between the fixing plates 18 and 18a, and the filter plate 2 is connected with the fixing frame consisting of the filter plates 18 and 18a. The rubber sheet 19 is slightly stretched to give tensile force when the rubber sheet is attached so that the deformation of the filter cloths 4 and 4a may be absorbed. Since the rubber sheet 19 is interposed between the filter plate 2 and the fixing frame as an elastic member, the deflection of the filter plate 2 due to the swelling of the filter cloths 4 and 4a in sludge can be controlled by the contraction of the rubber sheet 19.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical field to which the invention pertains) The present invention relates to a method for fixing a filter plate used in a sludge filtration and concentration apparatus.

(Prior art and its problems) Generally, sludge discharged from sewage treatment plants, etc.
Since it contains more than 8% water, the sludge is first allowed to settle by gravity and concentrated to a water content of 95-98%.
80% by mechanical dehydration using pressure or vacuum.
The cake is made into a cake with the following moisture content, and this cake is disposed of by incineration, landfill, etc.

Recently, the amount of sludge generated in sewage treatment plants and the like has tended to increase, and therefore there is an increasing need to increase the throughput of sludge treatment equipment and to save energy required for treatment. As a treatment method to achieve this, sewage sludge is introduced into a filter tank, water is filtered out using a filter plate, and the concentrated sludge is supplied to a dehydrator. It is extremely effective because it can increase the throughput of the machine by about twice. The filtration and concentration equipment used at this time is equipped with a filter plate over the entire area or part of the filtration tank, and the filtrate that has been processed through this filtration plate is discharged through a filtrate drain pipe, while the dehydrated thickened sludge is discharged from the bottom of the filtration tank. It should be drained.

FIG. 4 is a cross-sectional view showing an outline of the main structure for explaining such a filtration/concentration device. In FIG. 4, a filter plate 2 is installed in a filter tank 1, and this filter plate 2 is provided with filter cloths 4, 4! on both sides of a support plate 3 made of, for example, a net, respectively. This is then sewn around the area. Fixing of the filter plate 2 to the filter tank 1 will be described later. A filtrate discharge pipe 5 is connected to a part of the filter plate 2 and extends to the outside of the filtration tank 1, and a pulp 6 is attached thereto, but an air supply pipe 7 branches off in the middle and is led to a compressor (not shown). On the other hand, one end of a cake discharge pipe 8 is connected to the bottom of the filtration tank 1 from the outside so as to pass through the filtration tank 1, and a pump 10 is provided in the middle of the cake discharge pipe 8 via the pulp 9 outside the filtration tank 1. There is.

It was configured as above. When dewatering sewage sludge using a filtration thickener, sludge 1 is poured from the upper opening of filtration tank 1.
1 into the filter tank 1, and when the pulp 6 is opened, the sludge 1
1 is filtered between the support plate 3 and the filter cloths 4, 4α through the filter cloth 4° 4a of the filter plate 2, and the filtrate is discharged through the filtrate discharge pipe 5.

When the filtration of the water in the sludge 1 progresses and the cake 12, 12cL adheres to the surface of the filter cloths 4, 4α and the filtration performance decreases, the pulp 9 is opened and the pump 1o is activated to remove the sludge in the filtration tank 1. 11 is discharged from the cake discharge pipe 8. Next, the pump 1o is stopped, the pulp 9.6 is closed, and compressed air is supplied by a compressor (not shown) through the air supply pipe into the filter plate z, and the force of the compressed air blowing out causes the pulp to adhere to the surface of the filter cloth 4.4a. Cake 12.12! The cakes float up, peel off from the filter cloths 4 and 4g, and fall to the bottom of the filter tank 1, so the pulp 9 is opened again and the pump 10 is driven to remove the fallen cakes 12 and 124 through the cake discharge pipe 8 and outside the filter tank. discharge to.

To further explain the filter plate 2 of the filtration/concentration device having the above structure and function, the filter plate 2 is usually a hexagonal shape whose width becomes narrower at the bottom, as shown in the plan view in Fig. 5. As mentioned above, there are filter cloths 4 on both sides of the support plate 3. 4cL is applied and sutured around them, and an appropriate number of eyelets 13 are placed at a location slightly inside from the periphery as shown in FIG. The dotted lines in FIG. 5 represent thread stitches. As shown in a plan view in FIG. 6, this filter plate 2 has a wire rope 1 passed through a fixed frame 14 made of a square pipe whose outer dimensions are slightly larger than that of the filter plate 2.
5 in order to secure it. In this way, the required number of fixing frames 14 are fitted into guide grooves (not shown) provided on the inner surface of the filtration tank 1 shown in FIG. At this time, since the wire rope 15 is wound under tension, the filter plate 2 is pulled against the fixed frame 14 and is initially in a state without slack.

However, even if the filter plate 2 is installed in the filter tank 1 while being attached to the fixed frame 14 and stretched, the filter plate 2 will become loose when immersed in the sludge 11. That is filter plate 2
This is because the filter cloths 4 and 48, which are made of chemical fibers used in the sludge, have the property of swelling, and especially when the filter cloths 4 and 4α are made of nylon, their elongation due to swelling in the sludge is only a few percent. Become. Usually, in the filtration tank 1, a large number of filtration plates 2 attached to a fixed frame 14 are arranged with an interval of 100 to 2 QQms so that the longitudinal direction thereof is perpendicular to the bottom surface of the filtration tank 1. Therefore, when the filter cloths 4 and 4α swell and the filter plate 2 becomes slack, the surfaces of adjacent filter plates come into contact with each other, reducing the leakage area, and as a result, the sludge throughput of the filtration thickening device increases. This results in the disadvantage that the width decreases.

(Objective of the Invention) The object of the present invention is to eliminate the above-mentioned drawbacks, and to prevent the filter plate from loosening even when the filter plate is immersed in sludge and the filter cloth swells and stretches, and the adjacent filter plates are in contact with each other. The purpose of the present invention is to provide a method for fixing a filter plate without having to do anything.

(Summary of the Invention) In attaching the filter plate to the fixed frame, the present invention interposes a member having an elastic function between the filter plate and the fixed frame, and connects both ends of the elastic member to the filter plate and the fixed frame, respectively. By attaching the filter plate to the filter plate, the two are connected, and the deformation caused by the swelling of the filter plate is absorbed by the elastic member.

(Example of the invention) The present invention will be explained below based on examples.

FIG. 1 is a plan view of a filter plate attached to a fixed frame to which the method of the present invention is applied, and parts common to those in FIGS. 4 to 6 are denoted by the same reference numerals. The shapes of the filter plate 2 and the fixed frame 14 in FIG. 1 are the same as those in FIG. 6, so a description thereof will be omitted. The difference between FIG. 1 and FIG. 6 is that in FIG. 6, one wire row 115 is wound around the fixed frame 14 while passing through the eyelets 13 in sequence, whereas in FIG. A υ-shaped fixing metal fitting 16 is fixed on the inner side by welding or the like to the eyelet facing the eyelet 13, and the U-shaped metal fitting 16
The filter plate 2 is held by hanging the tip of a wire 17 having a coiled spring formed in the center between the eyelet 13 and the eyelet 13.

The wire 17 is made by stretching both ends of a coiled spring made of stainless steel wire to the required length to make a straight line.
It is sufficient to use one whose tip is shaped into a hook shape. However, the U-shaped metal fitting 16 provided at the bottom of the fixed frame 14 and the corresponding eyelet 13 are connected only by a wire without a coiled spring portion. In addition, this wire 17 is designed and manufactured with the wire diameter of the wire material, the number of turns of the spring part, the pitch interval, etc. appropriately selected so that the coiled spring part absorbs the elongation due to swelling of the filter cloth 2 and the spring part contracts. Must.

By doing this, the wire 17 will change depending on the deformation of the filter plate 2.
follows, and the pitch interval of the coiled spring portion is reduced, so that the filter plate 2 is always tense and does not bend even when immersed in sludge.Next, Figure 2 is different from Figure 1. FIG. 3 is a plan view showing a filter plate and a fixing frame using the fixing method, and FIG. 3 is an enlarged sectional view taken along line A-A in FIG. 2.

As shown in FIG. 3, this method involves forming a fixing frame with two fixing plates 18 and 18G to fix the filter plate 2, and using a rubber plate 19 to secure one end of the frame to the peripheral edge of the filter plate 2. Insert between the filter cloths 4 and 4eL and stitch with thread z2, and insert the other end of the rubber plate 19 between the fixing plates 18 and 18α and tighten the bolts 20. By fastening with nuts 21, the filter plate 2 and a fixed frame consisting of fixed plates 18 and 18α are connected.

The rubber plate 19 to be removed needs to be designed and manufactured into a suitable shape by considering the material properties and thickness, and is designed so that it can absorb the deformation of the filter cloths 4 and 4α by applying a tensile force when installing it. Leave it slightly stretched. Thus, in this case as well, the rubber plate 1 is used as an elastic member between the filter plate 2 and the fixed frame.
9, the filter cloth in the sludge is 4.4 g.
The deflection of the filter plate 2 due to the swelling of the rubber plate 19 is prevented by the contraction of the rubber plate 19, so that the filter plate 2 can always maintain its correct shape.

(Effects of the Invention) Conventionally, a filter plate used in a sludge filtration/concentration device was fixed by passing a wire rope through an eyelet hole provided in the filter plate and wrapping it around a fixed frame. As mentioned in the example, when a filter plate made by sewing a filter cloth and a support plate is immersed in sludge, the filter cloth swells and the filter plate is bent, so that adjacent filter plates do not come into contact with each other. Because elastic members such as coiled springs and rubber plates are interposed and fixed between the filter plate and the fixed frame, deformation of the filter plate is absorbed by these elastic members, and the filter plate is always in a tensioned state. Therefore, there is no phenomenon in which adjacent filter plates come into contact with each other due to deformation, and a large filtration area is maintained even during long-term use of this filter plate, and sludge can be dehydrated and concentrated in a stable state. I can do it.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing a method of fixing a filter plate according to the present invention, FIG. 2 is a plan view showing a method different from that in FIG. 1, and FIG.
The figure is a partial sectional view of FIG. 2, FIG. 4 is a sectional view of the main parts of a conventional filtration and concentration device, and FIG. 5 is a plan view of the filter plate.
FIG. 6 is a plan view showing the method of fixing the filter plate. 2: Filter plate, 3: Support plate, 4, 4α: Filter cloth, 13: Eyelet, 14: Fixed frame, 15: Wire rope 116: υ-shaped fixing fitting, 17: Wire, 18° 18α: Fixed plate,
19: rubber plate, 20: bolt, 21: nut, 22 double thread. Figure 1] Figure 2 Figure 4 Figure 5

Claims (1)

[Claims] 1) When attaching the filter plate used in the sludge filtration and concentration device to the fixed frame, an elastic member is interposed between the filter plate and the fixed frame, and both ends of the elastic member are attached to the filter plate. and a fixing frame. 2) In the method described in claim 1, a plurality of U-shaped metal fittings provided on the inner surface of each side of a fixing frame of a slightly larger rectangular pipe having the same circumference as the filter plate, and A coiled spring is formed in the center of a plurality of eyelet holes arranged near the periphery of the filter plate, facing the U-shaped metal fitting, and both ends of the wire are stretched in a straight line near both ends. 1. A method for fixing a filter plate of a filtration/concentration device, the method comprising hanging hook-shaped portions formed on each plate. 3) In the method described in claim 1, one end of the rubber plate is inserted into each side of the filter plate and sewn together with the filter cloth, and the other end of the rubber plate is attached to a rubber plate having the same circumference as the filter plate but slightly larger. A method for fixing a filter plate of a filtration/concentration device, which comprises inserting the plate between each plate of a fixed frame made up of two plates and fastening the plate together with the fixed frame using bolts and nuts.