JPH07204473A - Rotary filter device - Google Patents

Abstract

PURPOSE:To contribute to the enhancement of filtering capacity and the safety of a device and shorten a washing time due to a washing jig by equally holding the interval between filter elements. CONSTITUTION:In a rotary filter device wherein filter elements 6 each equipped with a membrane surface 10a for filtering a liquid to be treated are provided to the driving shaft arranged in a filter tank, a plurality of the washing jigs 11 provided to the driving shaft in a protruding state so as to leave a specific interval between the washing jigs in the peripheral direction of the driving shaft are arranged between the filter elements 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary filtration device for separating and concentrating bacterial cells and the like using a microfiltration membrane or an ultrafiltration membrane, which is provided in the rotary filtration device. The present invention relates to an improvement of a rotary filtration device equipped with a cleaning tool for cleaning the membrane surface of a filtration element.

[0002]

2. Description of the Related Art Conventionally, as a rotary filtration device of this type,
For example, there is a device disclosed in Japanese Utility Model Laid-Open No. 2-142606 by the applicant.

That is, in this conventional device, as shown in FIG. 5, a plurality of filter elements 6a having a membrane surface 10b are axially supported by a drive shaft 4b arranged in a filter tank 1a, and the filter elements 6a are also supported. In order to clean the film surface 10b between them, one cleaning brush as shown in FIG.
The base end of 14a is loosely inserted into the drive shaft 4b, the cleaning brush 14a is formed to have a width slightly larger than the gap width between the filter elements 6a, and the tip thereof is the membrane surface 10b of the filter element 6a. It is pressed against.

A stopper 15a for stopping the rotation of the cleaning brush 14a for cleaning the membrane surface 10b of the filtration element 6a is provided near the inner peripheral surface of the filtration tank 1a.
The stopper 15a stops the rotation of the cleaning brush 14a to clean the film surface 10b.

[0005]

By the way, in this type of rotary filtration device, it is desirable to keep the intervals between the filtration elements 6a uniform from the viewpoints of filtration performance and safety of the device.

However, for example, when the filter element 6a is made of synthetic resin, the filter element 6a is easily distorted due to the pressing force of the cleaning brush 14a.
Since there is only one 14a, a local pressing force is applied to the filter element 6a. As a result, the spacing between the filtering elements 6a on the side where the cleaning brush 14a is located is large, while the spacing is small on the side where the cleaning brush 14a is not located, so that distortion and inclination occur in the filtering element 6a, There is a problem that it is impossible to maintain a constant interval over the entire surface.

Moreover, when the filter element 6a is distorted and inclined as described above, the cleaning brush 14a causes the cleaning surface 14b of the filter element 6a to move.
There is a possibility that the film surface 10b may be damaged due to local contact with the film surface 10b.

Further, since a single cleaning brush 14a alone cannot provide a sufficient cleaning effect, it requires a longer cleaning time than required, resulting in a problem that the workability is extremely poor.

Therefore, the present invention has been made in order to solve the above-mentioned problems of the prior art, and contributes to improving the filtering performance and the safety of the apparatus by keeping the intervals between the filtering elements uniform. It is an object to shorten the cleaning time by the cleaning tool.

[0010]

That is, in order to solve the above-mentioned problems, the present invention provides a drive shaft 4 arranged in a filtration tank 1
In a rotary filtration device provided with a plurality of filtration elements 6 having a membrane surface 10a for filtering a liquid to be treated, a plurality of projections are provided on a drive shaft 4 at predetermined intervals in the circumferential direction. A cleaning tool 11 is a rotary filtration device arranged between the filtration elements 6.

[0011]

Therefore, in the rotary filtration device having the above-mentioned structure, a plurality of cleaning tools 11 projecting from the drive shaft 4 at predetermined intervals in the circumferential direction are arranged between the respective filtration elements 6. Therefore, the filter element 6 is evenly supported by the plurality of cleaning tools 11, and the intervals of the filter elements 6 can be maintained evenly over the entire surface. Further, at the time of cleaning, the plurality of cleaning tools 11 are provided.
As a result, the entire membrane surface 10a of the filter element 6 is washed in a short time.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a horizontally-arranged cylindrical filtration tank, and an opening / closing lid (not shown) is provided on a side surface of a circumferential surface thereof.
Is openable and closable. Reference numeral 2 denotes a liquid supply port to be treated which is provided on one side surface of the filtration tank 1, and 3 denotes a discharge port which is provided at a lower portion of the circumferential surface.

A hollow drive shaft 4 is rotatably attached to both side surfaces of the filter tank 1 so as to traverse the center of the filter tank 1. An exhaust port 4a is provided at one end of the drive shaft 4. The drive shaft 4 is an electric motor. It is rotationally driven by 5.

Reference numeral 6 denotes a drive shaft which can be inserted into the drive shaft 4 and which is shown in FIG.
As described above, a cylindrical boss 7 having a plurality of through holes 7a formed at equal pitches, a frame body 8 made of synthetic resin attached to the outer peripheral surface thereof, and a plurality of recesses formed on the front and back surfaces of the frame body 8 are formed. The filled synthetic resin porous body 9 and the filtration membrane 10 which covers the frame 8 by fitting.
A plurality of water collecting holes 7b that communicate the inside and the outside in the radial direction are provided at equal pitches in the boss 7, and the frame body 8 communicates with the water collecting holes 7b and the recess. Communication hole 8a
And a plurality of filter elements 6 having such a structure are fixed to the drive shaft 4 at regular intervals.

A cleaning tool 11 is provided between the filtration elements 6 to clean the membrane surface 10a of the filtration membrane 10. The cleaning tool 11 includes a cylindrical boss 12 which can be loosely fitted to the drive shaft 4. As shown in FIG. 3, it comprises a rod-shaped core body 13 protruding from the outer peripheral surface thereof at predetermined intervals in the circumferential direction, and a cleaning brush 14 in which a large number of brush bristles are planted on the core body 13. The core body 13 is formed in an arc shape, and the width of the cleaning brush 14 is set to be slightly larger than the interval width of the filter element 6.

Numeral 15 is a stopper for stopping the cleaning tool 11. The stopper 15 is a rotary shaft 16 arranged in parallel with the drive shaft 4 at a central position of the lower portion of the filtration tank 1, and a shaft of the rotary shaft 16. And a stop plate 17 projecting in the direction of the cleaning tool.
The tip of the core body 13 of 11 is engaged to stop its rotation.

The rotary filtration apparatus according to this embodiment has the above-mentioned structure. Next, an example of its use will be described.

First, after the liquid to be treated to be filtered is pressure-supplied from the supply port 2 of the filtration tank 1, the electric motor 5 is started to drive the drive shaft 4 to rotate, and the cleaning tool 11 rotates together with the filter element 6. Then, the liquid to be treated permeates the membrane surface 10a of the filtration element 6 and is filtered, and the permeated liquid permeating the membrane surface 10a and the porous body 9 communicates with the communicating hole 8a of the frame 8 and the water collecting hole 7b of the boss 7. Is discharged from the discharge port 4a to the outside through the drive shaft 4, and the treatment liquid concentrated by the filtration is appropriately discharged to the outside from the discharge port 3 of the filtration tank 1.

At this time, the liquid to be treated, which is in contact with the membrane surface 10a of the rotating filtration element 6, receives the rotational force thereof, is agitated and flows, and also flows through the through-flow holes 7a of the filtration element 6. In this way, the liquid to be treated flows and circulates in the entire filtration tank 1 without stagnation on the membrane surface 10a.

In this case, since the cleaning brush 14 of the cleaning tool 11 is formed in an arc shape along the flow direction of the liquid to be treated, the through hole 7a of the filtering element 6 is closed to prevent the flow of the liquid to be treated. It does not hinder the flow of the liquid to be treated on the film surface 10a.

Since a plurality of cleaning tools 11 are arranged at predetermined intervals in the circumferential direction between the filter elements 6, the filter elements 6 are uniformly pressed by the cleaning brush 14 at a plurality of locations. , The cleaning tool 11 evenly supports the filter element 6,
The intervals of the filtering elements 6 can be kept uniform over the entire surface. Therefore, the filter elements 6 are not distorted or tilted so that the filter elements 6 do not come close to or contact each other. Therefore, the through-flow holes 7a also function effectively, and good filtration performance can be secured without hindering the formation of the circulating flow of the liquid to be treated.

On the other hand, as the filtration process progresses, the filtration element 6
Since an adhesion layer made of fine particles or the like is formed on the film surface 10a, it is necessary to wash the film surface 10a to remove it.

In this case, after the rotational speed of the drive shaft 4 is reduced, the rotary shaft 16 of the stopper 15 is rotated to engage the stop plate 17 thereof with the core body 13 of the cleaning tool 11. As a result, the cleaning tool 11
Then, the cleaning brush 14 cleans the membrane surface 10a of the rotating filtration element 6.

Therefore, such cleaning is performed by using three cleaning brushes 14
As a result, the cleaning time can be shortened to one-third that of the conventional one, and the cleaning brush
Since 14 uniformly contacts the entire surface of the membrane surface 10a, there is no inconvenience that the adhering layer can be sufficiently removed and the filtration performance is deteriorated due to the remaining of the adhering layer, and the membrane surface 10a is damaged. Nothing.

Then, the removed deposits are resuspended in the liquid to be treated in the filtration tank 1, and the liquid to be treated in which the suspended concentration of fine particles is increased is, as described above, the outlet of the filtration tank 1. It is discharged from No. 3.

The cleaning tool 11 may be of any specific number as long as it is plural, and the shape thereof is not limited to the arc shape as in the above embodiment, and may be formed in a linear shape as shown in FIG. 4, for example. May be.

Further, the circumferential intervals of the cleaning tools 11 do not necessarily have to be equal intervals, and can be arbitrarily changed according to the number of the cleaning tools 11 and the like. I do not care.

The cleaning tool 11 has a core body 13 as in the above embodiment.
In addition to using the cleaning brush 14 in which a large number of bristles are planted on the circumferential surface of the cleaning tool 11, the cleaning tool 11 may be configured by inserting a tubular body made of a flexible material such as sponge into the core body 13.

Further, the cleaning tool 11 can be constructed by forming the core 13 in a flat plate shape and implanting a large number of brush bristles on both front and back surfaces thereof, that is, both surfaces facing the membrane surface 10a of the filter element 6. As a result, as compared with the case where the core body 13 is formed in a rod shape as in the above embodiment, the contact area with the film surface 10a can be secured, so that the cleaning performance is improved.

Besides, the specific construction of each part of the rotary filtration device can be arbitrarily changed in design within the scope intended by the present invention.

[0032]

As described above, according to the present invention, a plurality of cleaning tools projecting from the drive shaft at predetermined intervals in the circumferential direction are arranged between the filtering elements. Therefore, it is possible to keep the intervals of the filter elements even over the entire surface without causing distortion or inclination unlike the conventional one in which one cleaning brush is arranged between the filter elements. Become.

As a result, the liquid to be treated is satisfactorily circulated and the filtration performance is improved, and the membrane surface is not damaged. Therefore, it is possible to contribute to the improvement of the safety of the apparatus. Came to obtain the effect of.

Further, since the membrane surface of the filter element is cleaned by a plurality of cleaning tools, the cleaning time can be shortened, and since the cleaning tool hits the entire membrane surface for cleaning, the adhesion layer can be removed. It also has the practical effect of being able to do it completely.

[Brief description of drawings]

FIG. 1 is a front view including a partial cross section of a rotary filtration device showing an embodiment according to the present invention.

FIG. 2 is a plan view in which a part of a filter element is cut away.

FIG. 3 is a plan view of a cleaning tool arranged between filter elements.

FIG. 4 is a plan view showing another embodiment.

FIG. 5 is a front view including a partial cross section showing a conventional rotary filtration device.

FIG. 6 is a plan view of a cleaning tool arranged between the filter elements.

[Explanation of symbols]

 1 ... Filtration tank 4 ... Drive shaft 6 ... Filtration element 10a ... Membrane surface 11 ... Cleaning tool

Claims (3)

[Claims] 1. A drive shaft (4) arranged in the filtration tank (1),
In a rotary filtration device comprising a plurality of filtration elements (6) having a membrane surface (10a) for filtering a liquid to be treated,
A rotary filtration device characterized in that a plurality of cleaning tools (11) projecting from the drive shaft (4) are arranged at predetermined intervals in the circumferential direction between the filter elements (6). 2. The rotary filtration device according to claim 1, wherein the cleaning tool (11) is formed in an arc shape. 3. The rotary filtration device according to claim 1 or 2, wherein the core body (13) of the cleaning tool (11) is formed in a flat plate shape.