JPH11197424A - Ceramic filter medium and filtration device using this medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the backward wash effect and dispense with the washing of a membrane face after the backward washing and further, reduce the consumption of water for control and also a cleaning water, with the simplification of an operation to mount and remove a ceramic filter medium and an incidental installation. SOLUTION: A ceramic filter medium body 2a is formed of a columnar porous ceramic material, in which numerous small dia. through holes 3a are formed in the axial direction of the material. A row solution to be filtered is flown into the interior of the ceramic filter medium body 2a from its outer lateral face and the filtrate is flown out of the small dia. through holes 3a. The solid content such as a cladding contained in the row solution is captured by the outer lateral face of the ceramic filter medium body 2a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic filtering material for filtering radioactive waste liquid containing solids such as cladding, and a filtering device incorporating the ceramic filtering material.

[0002]

2. Description of the Related Art As shown in FIG. 4, a conventional ceramic filter medium 1 comprises a ceramic filter medium body 2 made of hexagonal columnar porous ceramics, and a large number of small-diameter penetrating holes are formed in the ceramic filter medium body 2 along the axial direction. It has a hole 3. Chemically resistant materials such as alumina and silica are used as ceramics.

In such a filter medium 1, a stock solution to be filtered flows into the small-diameter through hole 3 from above or below,
The filtered water is caused to flow out from the side surface of the ceramic filter medium body 2, and the solid residue such as clad is kept in the small-diameter through hole 3. That is, the undiluted solution is received from the small-diameter through hole 3 provided in the filter medium body 2, and water is passed from the small-diameter through hole 3 to the outside (side surface) of the filter medium body 2, so that solid components such as clad in the undiluted solution can be penetrated with the small diameter. It is captured in the hole 3 and filtered.

Next, a description will be given of a filtering device constructed by incorporating the above-mentioned conventional ceramic filtering material 1 into a body of a main body with reference to FIGS. 5 (a) and 5 (b). Note that FIG.
FIG. 3A is a cross-sectional view taken along line AA of FIG.

In FIGS. 5 (a) and 5 (b), reference numeral 4 denotes a cylindrical main body barrel having an upper end opening, in which a large number of ceramic filter media 1 shown in FIG. That is, both ends of each of the ceramic filter media 1 are fitted and fixed to the upper filter media mounting plate 5 and the lower filter media mounting plate 6. A plurality of tie rods 7 are interposed between the upper filter material mounting plate 5 and the lower filter material mounting plate 6 and are fixed to the upper and lower filter material mounting plates 5 and 6 by fixing bolts 8, and are integrated with the many ceramic filter media 1. Has been

Upper and lower seal rings 9 and 10 are provided between the upper filter material mounting plate 5 and the lower filter material mounting plate 6 and the main body 4 via a plurality of O-rings 11 to maintain airtightness. I have. The lower filter material mounting plate 6 is provided with a stock solution inlet hole 12. A head plate 13 is connected to a lower portion of the main body 4, and a head plate is provided.
A backwash water outlet nozzle 14 is attached to 13.

A stock solution inlet nozzle 15 is attached to a lower side surface of the main body 4 located above the backwash water outlet nozzle 14. The lower seal ring 10 has a pedestal structure for supporting the lower filter medium mounting plate 6, and is fixed by welding in the main body 4.

The main body 4 near the lower part of the upper filter medium mounting plate 5
A filtered water outlet nozzle 16 is attached to the upper filter material mounting plate 5
A hanging bracket 17 is fixed to the upper surface of the device. A packing 18 is interposed between the upper and lower filtration medium mounting plates 5 and 6 and the ceramic filtration medium 1.

A membrane surface cleaning water inlet nozzle 19 is attached to the upper side surface of the main body 4, and an overflow nozzle 20 is attached to the upper end side surface of the main body 4 located above by the inlet nozzle 19. A cover plate 21 is hermetically attached to an upper end opening of the main body 4 by fixing bolts and nuts 22. An eyebolt 23 is attached to the upper surface of the cover plate 21, and a mounting plate holding bar 24 is provided between the lower surface of the cover plate 21 and the upper surface of the upper filter material mounting plate 5. A plurality of lugs 25 are attached to the outer surface of the main body 4.

As described above, the filtering device incorporating the conventional ceramic filter medium 1 sandwiches the ceramic filter medium 1 between the upper and lower filter medium mounting plates 5 and 6, and mounts the two mounting plates 5 and 6.
Is fixed by a tie rod 7 and integrated into a hanging bracket.
It is structured to be suspended in the main body 4 by a lifting machine (not shown) using the 17.

FIGS. 6 to 8 show a normal operation mode, a backwashing operation mode and a membrane surface washing operation mode of the filtering apparatus having the above-mentioned structure. 6 to 8, reference numeral 26 denotes a filtered water receiving tank to which a filtered water inlet pipe 27 connected to the filtered water outlet nozzle 16 is connected.
A filtered water outlet pipe 28 is connected to an outlet side of the filtered water receiving tank 26, and a first valve 29, a flow meter 30, and a flow control valve 31 are sequentially connected to the filtered water outlet pipe 28 in series.

A compressed air supply pipe 32 is connected via a second valve 33 to the filtered water outlet pipe 28 on the inlet side of the first valve 29. A backwash water outlet pipe 34 is connected to the backwash water outlet nozzle 14 via a third valve 35. A stock solution supply pipe 36 for supplying a waste solution as a stock solution to be filtered into the main body 4 is connected to the stock solution inlet nozzle 15 via a fourth valve 37.

A cleaning water supply pipe 38 for supplying cleaning water into the main body 4 is connected to the membrane surface cleaning water inlet nozzle 19 via a fifth valve 39. A cleaning liquid pipe 40 for the raw liquid supply pipe is connected to the raw liquid supply pipe 36 via a sixth valve 41, branching from the inlet side of the fifth valve 39 of the cleaning water supply pipe 38.

Reference numeral 42 denotes a differential pressure gauge. The differential pressure gauge 42 is provided between a filtrate water inlet pipe 27 and a stock solution supply pipe 36 by a differential pressure measurement pipe 43.
Is provided via The compressed air supply pipe 32 branches from the outlet side of the second valve 33 and the compressed air drain pipe 44
Is connected via a valve 45. Overflow nozzle
A drain pipe 46 is connected to 20 via an eighth valve 47.

[0015]

In the above-mentioned prior art, as shown in FIG. 6, during normal operation, the first valve 29 and the fourth valve 37 are opened to allow water to flow through the inside of the main body 4, and a flow meter is provided. The flow rate is measured at 30, the flow rate is set to a constant flow rate by the flow control valve 31, and the filtration operation is performed.

In the system configuration shown in FIG. 7, when the pressure difference rises to a predetermined
If the flow has risen to the predetermined integrated flow rate, the fourth valve 37, the first
The valve 29 and the flow control valve 31 are closed to make them isolated, the second valve 33 is opened and pressurized with compressed air, then the third valve 35 is opened and the water in the filtered water receiving tank 26 is drained from the main body 4. A so-called backwash operation is performed in which water flows through the inside.

After that, in the system configuration shown in FIG. 8, the second valve 33 is closed after the second valve 33 is closed in order to discharge the solid matter such as the clad caught in the small holes of the ceramic filter medium 1 to the outer surface (side surface). The so-called membrane surface cleaning operation of passing the cleaning water through the main body 4 by opening the valve 39 of No. 5 is performed to recover the flow rate or the differential pressure.

However, since the conventional ceramic filter medium and its filtration device pass water from the inside to the outside of the ceramic filter medium 1, the filtration area is small, and the solid content such as cladding is insufficiently captured. Therefore, the backwashing effect is reduced, and it is necessary to wash the membrane surface after the backwashing, that is, to wash the surface of the ceramic filter medium body 2a. Therefore, there is a problem that the amount of control and washing water used is large, and the cost is increased.

Further, in the filtering device, both ends of a large number of ceramic filter media are fixed to the upper and lower filter media mounting plates, and the upper and lower filter media mounting plates are connected by a plurality of tie rods to be integrated with the ceramic filter media. Have been. For this reason, the mounting structure of the filter medium is complicated and heavy, requiring a lifting machine for loading and unloading into and out of the body of the main body. Furthermore, since the upper filter medium mounting plate is pressed and fixed from the cover plate by the mounting plate holding rod, there is a problem that the body of the main body becomes longer.

The present invention has been made in order to solve the above-mentioned problems, and has a large filtration area to capture solids such as cladding on the outside (side surface) of a wide ceramic filter medium, thereby improving the backwashing effect. No need to clean the membrane surface after backwashing, reduce the amount of control and washing water used, reduce costs, eliminate the need for a lifting machine, simplify the auxiliary equipment, and shorten the body of the ceramic filter material and its filtration. It is to provide a device.

[0021]

According to a first aspect of the present invention, there is provided a ceramic filter medium body for injecting a stock solution to be filtered from an outer surface to an inner side, wherein the body is formed of a cylindrical porous ceramic material. A large number of small-diameter through-holes for discharging a filtrate are provided in the porous ceramic material along the axial direction.

According to a second aspect of the present invention, the ceramic filter medium body for injecting the undiluted solution from the outer side to the inner side is formed of a cylindrical porous ceramic material, and the filter body is filtered along the axial direction with the cylindrical porous ceramic material. A large number of ceramic filter media provided with a large number of small-diameter through-holes for liquid discharge are detachably incorporated into the cylindrical main body via upper and lower filter media mounting plates,
An overflow nozzle is connected to the upper side of the main body body from the upper filter medium mounting plate, and a filtered water outlet nozzle is connected below the overflow nozzle. It is characterized in that a stock solution inlet nozzle is provided, and a backwash water outlet nozzle is provided on a head plate connected to a lower portion of the main body.

According to a third aspect of the present invention, the upper filter material mounting plate is provided with a through-hole for inserting the upper end of the ceramic filter material and communicating with the small-diameter through-hole. Characterized in that a stock solution inlet hole is provided.

According to a fourth aspect of the present invention, an undiluted liquid supply pipe is connected to the undiluted liquid inlet nozzle, and a filtered water inlet pipe is connected to the filtered water outlet nozzle. A differential pressure gauge is provided via a differential pressure measuring pipe.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a ceramic filter medium and a filter device thereof according to the present invention will be described with reference to FIGS. In FIGS. 1 to 3, the same parts as those in FIGS. 4 to 6 or the parts having the same functions are denoted by the same reference numerals.

In FIG. 1, a ceramic filter medium 1a is formed by forming a ceramic filter medium body 2a of, for example, alumina, silica or the like with a cylindrical porous ceramic material, and a large number of small diameters formed in the cylindrical porous ceramic material along the axial direction. Through hole 3
a. The diameter of the small-diameter through hole 3a is, for example, about 4 mm.

In this ceramic filter medium, when the undiluted solution flows from the outside (side surface) of the ceramic filter medium body 2a toward the inside, the filtered water passes through many small holes in the body 2a itself and through the small-diameter through holes 3a. The filtered water flows out. The solid content such as the clad is captured on the outer surface of the ceramic filter medium body 2a.

The solid content such as clad captured on the outer surface is easily peeled off by flowing backwashing water into the small-diameter through-hole 3a and flowing out to the outer surface. Therefore, according to the ceramic filter medium of the present embodiment, the backwashing effect is improved, the membrane surface cleaning after the backwashing becomes unnecessary, and the control and the amount of washing water can be reduced.

Next, referring to FIGS. 2A and 2B, a description will be given of an embodiment in which the ceramic filter medium 1a shown in FIG. 1 is incorporated in the main body 4a to constitute a filtration device. Note that FIG.
FIG. 2B is a cross-sectional view taken along the line AA in FIG.

In the main body 4a, the ceramic filter medium 1a having the structure described with reference to FIG. 1 is fixed by upper and lower filter medium mounting plates 48 and 49. In FIG. 2A, only two ceramic filter media 1a are shown for convenience of explanation.
Actually, as shown in the sectional view taken along the line AA in FIG. 2B, a large number of the filters are mounted on the upper and lower filter material mounting plates 48 and 49.

The upper filter material mounting plate 48 is provided with a through hole (not shown) for inserting the upper end of the ceramic filter material 1a and communicating with the small-diameter through hole 3a. The upper packing 50 is interposed between the outer peripheral surface of the upper end portion of the material 1a to maintain airtightness. The upper packing 50 is pressed from above by a fixing plate 51, and the fixing plate 51 is fixed to the upper filter material mounting plate 48 by bolts 52.

On the other hand, the lower filter material mounting plate 49 has a large number of waste liquid inflow holes 53 and a concave portion (not shown) for fixing the lower end portion of the ceramic filter material 1a. The airtightness with the lower end of the material 1a is maintained.

The main body 4a has an overflow nozzle 20 and a filtered water outlet nozzle 16 connected to an upper side surface, a stock solution inlet nozzle 15 connected to a lower portion, and a backwash water outlet nozzle 14 connected to a lower end portion. A baffle plate 55 is attached to the upper inner surface of the main body 4a so as to cover the inside of the overflow nozzle 20.

Next, the method of the ordinary filtration operation and the backwash operation of the filtration apparatus shown in FIG. 2 will be described with reference to FIG. FIG.
In the case where a normal filtration operation is performed, the second valve 33,
The sixth to eighth valves 41, 45 and 47 are closed, the first valve 29 and the flow control valve 31 are opened, and the waste liquid (stock solution) to be filtered is discharged to the fourth.
The valve 37 is opened to flow into the main body 4a from the stock solution inlet nozzle 15 through the stock solution supply pipe 36.

The undiluted solution that has flowed into the main body 4a is a waste liquid inflow hole.
The filtered water flows into the inside from the outer surface of the ceramic filter medium 1a through 53, and is filtered. The filtered water flows through the filtered water outlet nozzle 16 from the filtered water outlet nozzle 16 through the small-diameter through-hole 3a and enters the filtered water receiving tank 26. Sent to.

The filtered water stored in the filtered water receiving tank 26 is discharged from a filtered water outlet pipe 28 through a first valve 29, a flow meter 30, and a flow control valve 31. If the ceramic filter medium 1a is clogged during this filtration operation, the filtration operation is stopped and the operation is switched to the operation for backwashing.

During the backwashing operation, the system configuration shown in FIG. 3 was switched as shown by the thick line and the blacked portion, and when the pressure increased to a predetermined differential pressure by the differential pressure gauge 42, or increased to a predetermined integrated flow rate by the flow meter. In this case, the fourth valve 37, the first valve 29, and the flow control valve 31 are closed to be in an isolated state.

Then, the second valve 33 is opened and the inside of the main body 4a is filled with the filtered water receiving tank 26 and the filtered water inlet pipe 2 by compressed air.
7. After pressurized through the filtered water outlet nozzle 16, the third valve 3
5 is opened to perform a so-called backwash operation in which the filtered water in the filtered water receiving tank 26 flows through the main body 4a to recover the flow rate or the differential pressure.

Thus, according to the present embodiment, the ceramic filter medium 1a is formed in a columnar shape, and when filtering, for example, radioactive waste liquid containing solids such as clad, from the outside, that is, from the side of the ceramic filter medium body 2a. By passing water inward, solid content such as cladding can be captured on a wide outer surface.

A differential pressure gauge 42 is provided between the undiluted liquid supply pipe 36 connected to the undiluted liquid inlet nozzle 15 and the filtered water inlet pipe 27 connected to the filtered water outlet nozzle 16 via a differential pressure measuring pipe 43. After assembling the ceramic filter medium 1a into the main body 4a, the pressure resistance and leakage of the ceramic filter medium 1a can be easily confirmed by pressurizing the inside of the main body 4a through a compressed air line.

Further, the upper part of the ceramic filter medium 1a can be used as the secondary side water as filtered water, which is stored in the filtered water receiving tank 26 to reduce the amount of washing water used for back washing. It is not necessary to clean the outside of the ceramic filter medium 1a after backwashing, that is, the membrane surface.

Further, the ceramic filter medium 1a is attached to the main body 4a.
Since the work of attaching and fixing to the upper and lower filter media 48 and 49 in the inside can be performed in the main body 4a, a lifting machine is not required, the auxiliary equipment is simplified, and the cost can be reduced.

[0043]

According to the ceramic filter medium of the present invention, since the undiluted solution to be filtered from the outer surface (side surface) of the ceramic filter medium body toward the inside passes through, the filtration area can be widened, and the cladding and the like can be obtained. Wide solid surface (side surface)
Can be captured from In addition, since the backwash water flows from the small-diameter through-hole to backwash the outer surface (side surface) of the ceramic filter medium body, the backwash effect is improved, and the cleaning of the membrane surface after the backwash is not required, so that control and cleaning can be performed. Water consumption can be reduced.

According to the filtering device of the present invention, it is easy to mount or remove the ceramic filtering material inside the main body. In addition, the conventional tie rods, seal rings, suspension fittings, and mounting plate holding rods are not required, and the weight is reduced, so that a lifting machine is not required, the auxiliary equipment is simplified, the body of the main body is shortened, and costs can be reduced. Becomes Further, the pressure resistance and leakage of the ceramic filter medium after the ceramic filter medium is mounted in the main body can be confirmed using a compressed air system.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view showing an embodiment of a ceramic filter medium according to the present invention.

FIG. 2A is a longitudinal sectional view showing an embodiment of a filtration device according to the present invention, and FIG. 2B is a sectional view taken along the line AA in FIG.

FIG. 3 is a system diagram showing a mode during a backwash operation of the filtration device in FIG. 2;

FIG. 4 is a perspective view showing a conventional ceramic filter medium partially cut away.

5 (a) is a longitudinal sectional view showing a filtering device incorporating the ceramic filtering material in FIG. 4, and FIG. 5 (b) is a sectional view taken along the line AA in FIG. 5 (a).

FIG. 6 is a system diagram showing a mode during a normal operation of the filtration device in FIG. 5;

FIG. 7 is a system diagram showing a mode during a backwash operation of the filtration device in FIG. 5;

FIG. 8 is a system diagram showing a mode during a membrane surface cleaning operation of the filtration device in FIG. 5;

[Explanation of symbols]

1, 1a: ceramic filter medium, 2, 2a: ceramic filter medium body, 3, 3a: small-diameter through hole, 4, 4a: body body,
5: Upper filter medium mounting plate, 6: Lower filter medium mounting plate, 7: Tie rod, 8: Fixing bolt, 9: Upper seal ring, 10
... lower seal ring, 11 ... O-ring, 12 ... undiluted solution inlet,
13 ... end plate, 14 ... backwash water outlet nozzle, 15 ... undiluted solution inlet nozzle, 16 ... filtered water outlet nozzle, 17 ... hanging bracket, 18 ... packing, 19 ... membrane surface washing water inlet nozzle, 20 ... overflow nozzle, 21 ... Cover plate, 22: fixed bolt and nut, 23: eye bolt, 24: mounting plate presser bar, 25: lug, 26: filtered water receiving tank, 27: filtered water inlet piping, 28: filtered water outlet piping, 29: first Valve, 30: flow meter, 31: flow control valve, 32: compressed air supply pipe, 33: second valve, 34: backwash water outlet pipe,
35 ... third valve, 36 ... stock solution supply pipe, 37 ... fourth valve, 38 ...
Cleaning water supply pipe, 39: Fifth valve, 40: Cleaning water pipe for stock solution supply pipe, 41: Sixth valve, 42: Differential pressure gauge, 43: Differential pressure measurement pipe, 44: Compressed air drain pipe, 45 ... Seventh valve, 46 ... Drain piping, 47 ... Eighth valve, 48 ... Top filtration material mounting plate, 49 ...
Lower filter media mounting plate, 50… Upper packing, 51… Fixing plate,
52… Bolt, 53… Waste liquid inlet, 54… Bottom packing, 55
... Baffle plate.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI B01D 71/02 B01D 29/10 520B 530A 29/24 C

Claims (4)

[Claims] 1. A ceramic filter medium body for injecting an undiluted solution from an outer surface to an inner side is formed of a cylindrical porous ceramic material, and a small-diameter through-hole for filtrate discharge is formed in the cylindrical porous ceramic material along an axial direction. Ceramic filter media characterized by having a large number of holes. 2. A ceramic filter medium body for injecting the undiluted solution from the outer surface toward the inside is formed of a cylindrical porous ceramic material, and a small-diameter through-hole for filtrate discharge is formed in the cylindrical porous ceramic material along the axial direction. A large number of ceramic filter media provided with a large number of holes are detachably incorporated into the cylindrical main body through upper and lower filter media mounting plates, and on the side of the main body trunk above the upper filter media mounting plate. An overflow nozzle was connected, a filtrate outlet nozzle was connected below the overflow nozzle, and a stock solution inlet nozzle was provided on a side surface of the main body below the lower filter material mounting plate, and connected to a lower part of the main body. A filtration device comprising a head plate provided with a backwash water outlet nozzle. 3. An upper end of the ceramic filter medium is inserted into the upper filter medium mounting plate, and a through hole communicating with the small-diameter through hole is provided. The lower filter medium mounting plate has a plurality of undiluted liquid inlet holes. 3. The filtration device according to claim 2, wherein the filtration device is provided. 4. A raw liquid supply pipe is connected to the raw liquid inlet nozzle, a filtered water inlet pipe is connected to the filtered water outlet nozzle, and a differential pressure measuring pipe is provided between the filtered water inlet pipe and the raw liquid supply pipe. 3. The filtering device according to claim 2, wherein a differential pressure gauge is provided through the filter.