JPS62258715A - Filter apparatus using floatable filter material - Google Patents

Abstract

PURPOSE:To perform washing well within a short time without sending back a large quantity of filtered water at the time of the regeneration of a floatable filter material, by allowing the floatable filter material filling a filter tank to fall and move in the separation tank communicating with the lower part of the filter tank. CONSTITUTION:A filter bed 7 is formed in a filter cylinder 1 provided with a liquid entrance and exit 5 by a floatable granular filter material 8 and a moving screen 3 for preventing the outflow of the filter material 8 free from the inner periphery of the cylinder 1 is allowed to load on the top part of the filter bed 7 by utilizing the buoyancy of the filter material 8. Further, a filter material regenerating and separating tank 2 having an inverted cone shape is constituted so as to be fixed to the lower part of the cylinder 1 in coaxial relation to the cylinder 1. When the filter material 8 is regenerated, said filter material 8 is moved to an up-and-down direction by allowing the liquid level in the filter tank to fall or rise. By this motion, the suspended substance collected and confined between filter material particles is released. Further, filtered water is sent back from the top part and the filter bed 7 can be re-formed while the filter material 8 is washed by flow-down water.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to the regeneration of a floating filter medium used in a filtration device for solid-liquid separation.

[Conventional technology]

Conventionally, the biggest problem with filtration devices is the quality of the cleaning method used to regenerate the P material. In other words, as filtration continues, the filtration layer becomes increasingly clogged, and when the head loss increases, filtration is stopped and the filter medium is washed and regenerated.Washing is mainly done by back-feeding filtered water, but additional Generally, regeneration methods using mechanical agitation, air agitation, etc. were common. Floatability P
A filtration device using i was also a regeneration method of these, but
However, a recycling method unique to buoyant P material, which is not available in conventional technology, was priced at a low price.

[Problem that the invention seeks to solve]

However, in conventional filtration devices that consist of a layer of buoyant filter media, because the filter media itself has buoyancy, it has poor agitation when mixed with backwash water during cleaning, and hydraulic agitation by backwash water or backwash water is difficult. In either case, such as mechanical stirring performed while supplying water or air stirring that mixes air bubbles, a sufficient cleaning effect cannot be obtained in a short time, and suspended solids remain trapped in the filter medium. For this reason, it is necessary to send back filtered water at a temperature of about 5° C. during washing, which has the disadvantage of requiring a long washing time. Moreover, if strong stirring is used to overcome this problem, the filter material will be worn out considerably due to the nature of the filter material, which will impair the economic effect. Furthermore, there is a problem in that the cost is unavoidably high because various devices are added separately.

Therefore, the present invention was invented to solve the drawbacks mentioned above. The purpose is to be able to perform good cleaning in a short time without having to send large amounts of filtrate water back when regenerating filter media, and to regenerate the furnace bed without adding various devices, which is the case with conventional regeneration methods. It is an object of the present invention to provide a filtration device that can be formed and continuously perform smooth filtration operations.

[Means for solving problems]

In order to achieve the above object, the filtration device of the present invention having a buoyant filter material as a furnace layer has a structure including a cylindrical filtration tank in which the filter material is filled in the upper part, and an inverted conical shape in which the filter material is introduced in the lower part. In this device, a separation tank is provided, which is connected to a filtration tank and fixed to a coaxial line, and a liquid inlet/outlet is attached to each of them, and the liquid is manipulated during regeneration to change the liquid level. Following this, the buoyant filter medium moves up and down between the filtration section and the separation section and reciprocates. By making this movement back and forth, the purpose can be easily achieved.

[Effect]

Next, the action of regenerating and cleaning the floating filter medium of the present invention will be explained based on the above configuration. First, as the filtration progresses, the furnace bed becomes clogged and the head loss rises. When the filtration is interrupted and the filter media is regenerated, the filter media is moved vertically by lowering or raising the liquid level in the filtration tank. let Due to this movement, the suspended solids trapped between the particles of the filter medium are released. Furthermore, filtered water is sent back from the top, and the furnace layer can be reformed while washing the filter medium with flowing water.

〔Example〕

Hereinafter, embodiments embodying the present invention will be described with reference to the drawings. Here, FIG. 1 is a longitudinal sectional view of the filtration device.

In Figure 1, a filtration layer (■) is formed using buoyant granular filter media inside a cylindrical mountain for filtration with a liquid inlet/outlet (■), and the top of the filter layer (■) is free from the inner periphery of the cylinder to prevent outflow of the filter material. Using the buoyancy of the filter medium to move the screen ■, m il, -r
Ru. A separation tank for filter media regeneration in the shape of an inverted cone is fixedly attached to the lower part of the cylinder a) with the phantom being coaxial with the cylinder.

A tangentially mounted raw liquid inlet (4) is provided on the shoulder of the part 41 (g), which generates a swirling flow in the separation tank CQ) for sedimentation and separation of suspended solids in the liquid before filtration. is promoted. Separation tank (the lower part of the illusion is a storage tank for concentrated sludge, and the lowest part of the tank has a sludge outlet.
is the provision.

Figure 1 is a diagram showing the state of filtration.

Therefore, the stock solution containing suspended solids that is not sedimented and separated by the swirling flow described in TIIF is passed upward from the bottom of the filtration layer (?), completes the filtration process, and is passed through the upper liquid inlet/outlet (5) as a treated liquid. be discharged.

FIG. 2 shows the state after the first step of regenerating and cleaning the filter medium, and will be explained below with reference to the figures. Close the stock solution inlet ■,
The sludge outlet r is opened, and the sludge that was sedimented, separated, and concentrated during the filtration time of the previous stage is discharged, and at the same time, air is allowed to flow into the filtration cylinder through the liquid inlet/outlet (0) at the top of the filtration tank. As a result of this action, the liquid that has been filtered in the previous stage and filled in the cylinder (2) starts to gradually fall in the filter layer (7) from the discharge top, and as the liquid level falls, the filter layer (r ') loses its buoyancy, and the entire filter layer (7) follows the drop of the liquid level and moves downward due to the filter medium's own weight and the action of the electric field such as the moving screen (2) at the top of the furnace layer.

As a result of this movement, the -vortex layer ■ gradually reaches into the separation tank ■ from the lower part, and further descends to the vicinity of the shoulder (point a) in the separation tank mountain, and the filter medium moves horizontally toward the outer circumference due to its buoyancy on the expanded liquid surface. The filter media unfolds, and the pressure of the weight of the moving screen on top causes the layer to become thinner and more spread out. The greatest feature of the present invention is that the buoyancy of the filter medium is effectively utilized by changing the liquid level. That is, in the first step, the sources of movement such as decomposition or crushing, transfer, and spreading of the filter layer are the filter medium's own weight and buoyancy, and this action causes the floating particles that have been captured and restrained on the surface of the filter medium or between the particles to The material is released from the filter media and is easily separated.

Referring to FIG. 2, the figure shows the state in which the first step has been completed. It also shows the state at the start of the second step. In the second process operation, the raw solution inlet (4) is kept closed, the sludge outlet (2) is closed, and the filtrate obtained in the previous stage treatment is sent back through the upper liquid inlet/outlet (5), thereby transferring the filtrate to the separation tank (2).
The liquid level begins to rise, and the filter material (8) thinly spread in the tank uses its buoyancy to push up the moving screen ■, gathering in the center and moving the screen inside the cylinder faster than the rising speed of the liquid level. What is important at this time is that in the second step, the filter medium is further washed in countercurrent by the flowing down of the clean filtrate from the previous stage, which is sent back while the filter medium is rising.

At this time, the moving screen (3) is manufactured to have a water sprinkling function for uniform cleaning.

In the second step, the cleaned filter medium recovers its function and is filled with the filtrate sent back, rising and compacting due to its own buoyancy, re-forming the filtration layer (■), and returning to the position shown in Figure 1 of the example. Re-functions as a filtration device.

Note that the present invention is not limited to the above embodiments,
It is clear that various modifications can be made without departing from the gist of the invention. Figures 3 and 4 are cross-sectional views of modified embodiments having different shapes from the embodiments described above. In the case of this example diagram, the filtration cylinder (7) and the separation tank ■? This is an embodiment in which the diameter is the same and an orifice (ω) is provided in the middle of both openings to reduce the passage cross section of the filter medium. Fig. 3 shows a passage hole in the center, and Fig. 4 shows a passage hole on the outer periphery. As described in the example description, this is a modified example in which the first step of crushing and separating the filtration layer during its descent is performed by passing through a constricted portion formed by an orifice.

〔Effect of the invention〕

As is clear from the above description, according to the effects of the present invention, the filtration function can be easily performed by lowering and raising the liquid level when regenerating and cleaning the filter medium, and by using a smaller amount of reverse water flow than the conventional method. There is no need to add a separate playback function, making it simple and inexpensive.

[Brief explanation of drawings]

Figure 1 is a longitudinal sectional view of the filtration device, Figure 2 is a longitudinal sectional view showing the state at the completion of the first step in the example, and the state at the start of the second step, Figures 3 and 4 are FIG. 7 is a longitudinal cross-sectional view showing a modified example. 1 - Filtration cylinder 2 - Separation tank 3 - Moving screen 4 - Raw solution population 5 - Liquid inlet/outlet 6 - Sludge outlet 7 - Filter layer 8 - Filter medium 9 - Orifus Patent applicant Yuki Engineering Co., Ltd. Figure 1
Figure 2 Figure 3 Figure 4

Claims (3)

[Claims] (1) A filtration device in which a filtration tank is filled with a flotation filter medium, characterized in that a separation tank is provided in communication with the lower part of the filtration tank, and the filter medium is moved down into the separation tank during regeneration cleaning. (2) The filtration device according to claim 1, characterized in that it comprises a narrow passageway between the upper filtration tank and the lower separation tank. (3) The filtration device according to claim 1, further comprising a separation tank having a horizontal cross section larger than that of the filtration tank.