JP2691846B2 - Solid-liquid separation method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to SS (Suspend)
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid-liquid separation method and apparatus used for separation and purification of various stock solutions containing ed Solids;

[0002]

2. Description of the Related Art Conventionally, as this type of solid-liquid separation method,
In order to cope with automation of the separation process and the like, cross flow filtration is generally performed. In cross-flow filtration, a cylindrical or spiral filter made of ceramics or polymer material having an asymmetric structure is inserted in the circulation path of the stock solution, and while the stock solution is flowing along the membrane surface, the filtrate (depleted stock solution) ) Is a solid-liquid separation method of vertically flowing out from the membrane surface.

[0003]

However, in the conventional solid-liquid separation method by cross-flow filtration, the filter is clogged by SS, so back pressure washing (back washing) must be performed frequently and the concentration is increased. While the magnification and the filtration pressure increase with time, there is a problem that the filtration flow rate decreases with time, and in particular, an abnormal increase in concentration or the like may occur at the final stage of filtration. Therefore, an object of the present invention is to provide a solid-liquid separation method and an apparatus therefor capable of reducing the number of backwashing steps and efficiently performing stable separation.

[0004]

In order to solve the above-mentioned problems, the first solid-liquid separation method of the present invention is to separate a stock solution containing SS into a primary concentrated stock solution containing heavy specific gravity and a low specific gravity by centrifugal force. It is a method of semi-totally filtering the above-mentioned primary impaired stock solution into a secondary concentrated solution and a secondary impaired stock solution by classifying it into a primary impregnated stock solution containing the same. The second solid-liquid separation method is
In the above method, when the filtration capacity is lowered, the classification and the filtration are interrupted, and the stock solution during the classification and the primary depleted stock solution during the filtration are discharged to the outside of the system by discharging backwashing water in an amount larger than these. The third solid-liquid separation method is a method of separating the classified primary concentrated stock solution and / or filtered secondary concentrated stock solution into a stock solution and a slurry component in the above method.
On the other hand, the first solid-liquid separation device is used for carrying out the above method, and is a liquid cyclone for classifying a stock solution containing SS into a primary concentrated stock solution containing a heavy specific gravity content and a primary depleted stock solution containing a low specific gravity content. And, the primary depleted undiluted solution classified by the liquid cyclone becomes about ⅕ of the primary depleted undiluted solution.
Thus, a filtration module for filtering half of the secondary concentrated stock solution and the secondary depleted stock solution by cross-flow filtration is provided. The second solid-liquid separation device is the above-mentioned device, and is provided with a back-washing device capable of discharging a back-washing-injected water amount equal to or more than the inner volume of the primary side of the filtration module and the liquid cyclone. Further, the third solid-liquid separation device is the same as the above-mentioned device, in which the primary concentrated stock solution classified by the hydrocyclone and / or the second concentrated solution is filtered by the filtration module.
A bucket strainer for separating the next concentrated stock solution into a stock solution and a slurry component is provided. Here, the semi-total filtration means that the secondary concentrated stock solution is 1 / th of the primary depleted stock solution in one filtration.
2 to be about 5 (specifically about 10 to 25%)
Separated from the next impaired stock solution (filtrate).

[0005]

[Action] In the first method and apparatus, and a small amount of secondary concentration stock solutions and a large amount of secondary impairment stock almost entire amount in a single cross-flow filtration of primary impairment stock removed heavy specific gravity fraction Filtered. Further, in the second method and apparatus , the gel and the primary concentrated stock solution, which cause the clogging of the filtration module, can be discharged to the outside of the system. Furthermore, the third method
And apparatus , the primary concentrated stock solution and / or the secondary concentrated
Stock solution is the stock solution and the slurry minute and two-minute Hanareka ability.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a flow chart showing an embodiment of the solid-liquid separation device of the present invention. In the figure, 1 is a filtration module, and this filtration module 1 is, for example, as shown in FIGS.
A hexagonal prism having a cylindrical stainless steel casing 3 having flanges 2 at both ends, and a large number of passages 4 penetrating in the axial direction (vertical direction in FIG. 2) in the casing 3. of ceramic Khufu filter 5 are coaxially fitted to form a filtrate chamber 7 between the cylindrical wall of the casing 3 through the ring-shaped support fitting 6 and the like attached to the flange 2 at both ends . Ceramic filter 5
Is made of high-purity alumina ceramics and has an asymmetric membrane structure in which the open pore diameter gradually increases from the inner side surface of each passage 4 serving as a filtration surface toward the outer side. The open pore diameter is 0.1 μm.

Further, nozzles 8 and 9 communicating with the filtrate chamber 7 are attached to the cylindrical walls at both ends of the casing 3, respectively. The upper nozzle 8 is mainly used as an outlet for the filtrate, and the lower nozzle 9 is mainly used as an inlet for a cleaning liquid for backwashing. Further, at one end (lower end in FIG. 2 and FIG. 3) of the casing 3, a hydrocyclone 10 integrally provided with the support fitting 6 is continuously provided, and the hydrocyclone 10 is provided with a cylindrical portion 11 and this. It is composed of a conical portion 12 that is continuous. The hydrocyclone 10 classifies an undiluted solution containing SS by centrifugal force into a primary concentrated undiluted solution containing heavy specific gravity and a primary depleted undiluted solution containing low specific gravity. Is provided tangentially, and the upper end opening of the cylindrical part 11 is used as an overflow port 14 to communicate with one end (lower end in FIG. 2) of each passage 4 of the ceramic filter 5. On the other hand, the lower end opening of the conical portion 12 serves as an underflow port 15. The other end of the casing 3 that communicates with the other end (upper end in FIG. 2) of each passage 4 of the ceramic filter 5 has a secondary concentrated stock solution outlet 16
It has been.

The stock solution inlet 13 of the liquid cyclone 10
Is connected to the discharge port of the pump 17 for supplying the stock solution by the stock solution supply passage 18, and the stock solution supply passage 18 is provided with the first electric valve 19 and the first electric valve 19.
Before and after, the pressure switch 20 and the first pressure gauge 21 are branched and connected. Further, the underflow port 15 of the liquid cyclone 10 is connected to a bucket strainer 24 via a primary concentrated stock solution discharge passage 23 in which a second electric valve 22 is inserted. The bucket strainer 24 is for separating the primary concentrated stock solution into a stock solution and a slurry component. The separated stock solution, a stock solution outlet 25 for discharging the slurry content, and a drain port 26 are provided, and the slurry content is collected. A compressed air inlet 27 is provided for squeezing and cleaning the bucket strainer 24.

On the other hand, one nozzle 8 of the filtration module 1
To the first solenoid valve 2
9 and the flowmeter 30 are inserted in order from the casing 3 side 2
A next- depleted stock solution (filtrate) delivery path 31 is connected, and a backwash cylinder 32 is connected to the other nozzle 9.
The backwash silling 32 stores the secondary depleted stock solution for backwashing the ceramic filter 5, etc., and is on the primary side of the filtration module 1, that is, each passage 4 and the hydrocyclone 10.
Has a volume capable of discharging the amount of backwashing water that is greater than or equal to the volume of the fluid, and is connected to a pressure source (not shown) such as a compressor by a compressed air passage 34 in which a second solenoid valve 33 is inserted. In the compressed air passage 34, an exhaust passage 36 having a third solenoid valve 35 interposed is provided with a second solenoid valve 33 and a backwash cylinder 32.
It is branched and connected between and. The second and third solenoid valves 33, 35 are provided so as to be closed by a level switch 37 attached to the backwash cylinder 32. In addition, the secondary concentrated stock solution outlet 16 of the filtration module 1
The outflow amount of the secondary concentrated stock solution from the secondary concentrated stock solution outlet 16 is about ⅕ of the inflow amount of the primary depleted stock solution from the overflow port 14 of the hydrocyclone 10 (specifically, 10).
The fourth solenoid valve 38 that can be restricted to about 25%)
It is connected to the bucket strainer 24 by a secondary concentrated stock solution discharge path 39 inserted through. In FIG. 1, reference numeral 40 denotes a valve communicating with the filtrate chamber 7.
This is for draining the second impaired stock solution (filtrate).

In order to separate an undiluted solution containing SS using the solid-liquid separator having the above structure, first, the first electric valve 19, the first solenoid valve 29 and the fourth solenoid valve 38 are opened (the fourth solenoid valve is (Slightly opened)
Then, the pump 17 is driven to feed the undiluted solution to the liquid cyclone 10
Supply to The stock solution that has flowed into the hydrocyclone 10 is classified by centrifugal force, and the primary concentrated stock solution containing the heavy specific gravity is settled in the lower part thereof, while the primary depleted stock solution containing the low specific gravity is filtered from the overflow port 14. It is introduced into one end of each passage 4 of the module 1 and is cross-flow filtered. Along with this cross-flow filtration, the secondary depleted stock solution is sent from the filtrate chamber 7 to the required location via the secondary depleted stock solution delivery passage 31, while the secondary depleted stock solution is about ⅕ of the inflow amount of the primary depleted stock solution. concentrated stock solution is discharged into a bucket strainer 24 through the secondary concentrate original liquid discharge paths 39, where it is separated into stock and the slurry fraction is discharged respectively from a stock solution outlet 25 and drain outlet 26. The course of the cross-flow filtration, the filtration efficiency of the ceramic Cheops filter 5 of the filtration module 1 is reduced, and stops driving of the pump 17, the first electric valve 19 is closed, and the second electric valve 22 open At the same time, the second solenoid valve 33 is opened and closed to remove compressed air from the pressure source in the backwash cylinder 3
2, the secondary depleted stock solution in the backwash cylinder 32 is caused to flow into the filtrate chamber 7 and pulse pressure is applied to the secondary side of the filtration module 1 to backwash the ceramic filter 5.
The backwashing of the ceramic filter 5, a primary concentrated stock solutions in peeling gel and hydrocyclone 10 from the inner surface of each of the passages 4 is discharged into a bucket strainer 24, as in the case of secondary enrichment stock stock and a slurry fraction And is discharged from the stock solution outlet 25 and the drain port 26. Note that the bucket strainer 24 is cleaned by supplying compressed air from the compressed air inlet 27 and squeezing SS or the like at the time of maintenance or the like in order to prevent clogging of the bucket strainer 24. Further, the inflow of the secondary depleted stock solution into the backwash cylinder 32 is performed during the filtration operation by the filtration module 1.

Here, the solid-liquid separation device (membrane area 0.6
m ² ), backwashing for 20 minutes cycle (compressed air pressure 5 k
While performing gf / cm ² and backwashing water amount 21), solid-liquid separation of the electric discharge machining liquid is performed for about 8 hours while the secondary concentrated stock solution amount is ⅕ of the primary depleted stock solution amount. Using a conventional cross-flow filtration type solid-liquid separation device (membrane area 0.6 m ² ) having no cyclone, backwashing was performed in a cycle of 20 minutes (pulse backwashing, compressed air pressure 5 kgf / cm ² , backwashing injection water amount 0. 21) was carried out and solid-liquid separation of the same stock solution was carried out for about 8 hours. As a result, the respective concentration ratios were as shown in FIG. 4, and the filtration pressure and the filtration flow rate were as shown in FIG. It was Therefore, according to the solid-liquid separation device of the present invention, the amount corresponding to the cross-flow circulation amount is the total of the primary concentrated stock solution and the primary impaired stock solution, and the running cost is reduced to 1/9 or less. . Further, it can be understood that the concentration ratio, the filtration pressure and the filtration flow rate can be stabilized over a long period of time without causing a large change with time as in the conventional one.
Similarly, using a solid-liquid separator (membrane area 0.6 m ² )
20 minutes cycle backwash (compressed air pressure 5 kgf / cm ² ,
While performing backwashing water amount 21) and performing solid-liquid separation of the electric discharge machining liquid for about 8 hours so that the secondary concentrated stock solution amount becomes 1/5 of the primary depleted stock solution amount, the liquid cyclone 10 is not provided. When the solid-liquid separation of the electric discharge machining liquid was performed for about 8 hours using the above-mentioned solid-liquid separator under the same conditions, the filtration pressure and the filtration flow rate were as shown in FIG. Therefore, it can be seen that by providing the liquid cyclone as in the solid-liquid separation device according to the present invention, selective filtration in the filtration module 1 becomes possible and the filtration pressure and filtration flow rate can be stabilized over a long period of time. Further, similarly, a solid-liquid separator (membrane area: 0.6 m ² ) was used to perform backwashing (compressed air pressure: 5 kgf / cm ² , backwashing water amount: 21) in a 20-minute cycle, and the secondary concentrated stock solution amount was 1 The solid-liquid separation of the electric discharge machining liquid is performed for about 8 hours so as to become 1/5 of the next-depleted stock solution, while the secondary concentrated stock solution amount becomes zero, that is, the fourth solenoid valve 38 is closed to perform the solid-liquid separation. When the electric discharge machining liquid was subjected to solid-liquid separation in the same backwash cycle using the apparatus, the filtration pressure and the filtration flow rate were as shown in FIG. 7. Therefore, by discharging a part of the secondary concentrated stock solution to the bucket strainer 24 as in the solid-liquid separation device according to the present invention, the backwash interval can be extended and the concentration rate can be adjusted. (The concentration rate in one cycle has a correlation with the outflow amount of the secondary concentrated stock solution and the inflow amount of the primary depleted stock solution.) It can be seen that the filtration pressure and the filtration flow rate can be stabilized over a long period of time. .

In the above embodiment, the case where the filtration module 1 having the ceramic filter 5 having the asymmetric membrane structure is provided has been described, but the filtration module is not limited to the one having the ceramic filter 5, and for example, the asymmetrical structure is possible. or as having a polymer filter film or multilayer Gomaku structure. Also, before the liquid cyclone,
A cartridge filter or an activated carbon filter may be installed together. Further, an ion-exchange resin cartridge may be inserted in the secondary depleted stock solution delivery path, which makes it possible to further expand the use of pure water for regeneration.

[0013]

As described in the foregoing, according to the first solid-liquid separation method and apparatus of the present invention, in almost all of one cross-flow filtration of the primary impairment stock removed heavy specific gravity fraction since the filtered and a small amount of secondary concentration stock solutions and a large amount of secondary impairment stock, can be enhanced throughput or processing efficiency, of course, it is possible to significantly reduce the running cost by reducing the number of backwash times In addition, stable separation can be efficiently performed. Further, according to the second solid-liquid separation method and its apparatus,
For example, in addition to the function and effect of the first method and device , it is possible to dispense the gel and the primary concentrated stock solution that cause the clogging of the filtration module, so that the filtration pressure and the filtration flow rate can be further stabilized. Furthermore, the third solid-liquid separation method and
According to the first and second methods and apparatuses,
In addition to the action and effect described above, primary concentrated stock solution and / or secondary concentrated stock solution
Since but the stock and the slurry component and the binary Hanareka ability to wash, such as a conventional stock solution circulation tank as can be made unnecessary.

[Brief description of the drawings]

FIG. 1 is a flow chart showing an embodiment of a solid-liquid separation device of the present invention.

FIG. 2 is a front view, in half cross-section, of a main part of the solid-liquid separation device shown in FIG.

FIG. 3 is a side view of a main part of the solid-liquid separation device shown in FIG.

FIG. 4 is an explanatory diagram showing a change in concentration ratio of the solid-liquid separator shown in FIG. 1 in comparison with a conventional one.

FIG. 5 is an explanatory diagram showing a comparison of a filtration pressure and a filtration flow rate between the solid-liquid separation apparatus shown in FIG. 1 and a conventional one different from the backwashing method.

FIG. 6 is an explanatory diagram showing a comparison between the filtration pressure and the filtration flow rate of the solid-liquid separation device shown in FIG. 1 and one without a liquid cyclone.

7 is an explanatory view showing in comparison the filtration pressure and filtration flow rate of 1 and solid-liquid separator shown in shall be dead-end filtration by using this.

[Explanation of symbols]

 1 Filtration Module 10 Hydrocyclone 19 1st Motorized Valve 22 2nd Motorized Valve 24 Bucket Strainer 32 Backwash Cylinder 33 2nd Solenoid Valve 35 3rd Solenoid Valve 38 4th Solenoid Valve

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Yuji Yokotani No. 1 Nanto, Ogakie-cho, Kariya city, Aichi Toshiba Ceramics Co., Ltd. Kariya factory (56) Reference JP-A-62-294410 (JP, A) JP-A-62 -234515 (JP, A) JP-A 64-43305 (JP, A)

Claims (6)

(57) [Claims] 1. A stock solution containing SS is centrifugally separated into a primary concentrated stock solution containing a heavy specific gravity content and a primary impaired stock solution containing a low specific gravity content, and the primary impaired stock solution is subjected to cross-flow filtration. /> solid-liquid separation method which is characterized in that semi-dead end filtration good Ri to the secondary concentrated stock solutions and secondary impairment stock. 2. When the filtration capacity is lowered, the classification and filtration are performed
Cut off the undiluted solution during classification and the primary depleted undiluted solution during filtration.
Discharge to outside the system by spitting backwashing water in the above amount
The solid-liquid separation method according to claim 1, which comprises: 3. The classified primary concentrated stock solution and / or
Separation of filtered secondary concentrated stock solution into stock solution and slurry
The solid-liquid separation method according to claim 1 or 2, characterized in that
Law. 4. A liquid cyclone for classifying an undiluted solution containing SS into a primary concentrated undiluted solution containing heavy specific gravity and a primary depleted undiluted solution containing low specific gravity, and 1 classified by the liquid cyclone.
Secondary concentrated stock solution is approximately 1/5 of the primary concentrated stock solution
Secondary concentrated stock solutions by cross-flow filtration so that the 2
A solid-liquid separation device comprising: a second impaired stock solution and a filtration module for semi-total filtration. Wherein said solid-liquid separation device according to claim 4, characterized in that it comprises a backwash means capable ejecting primary and backwash implantation amount of water than the internal volume of the hydrocyclone filtration module. 6. filtration of the primary concentrated stock solutions and / or filtration modules classified by the liquid cyclone
Claim, characterized in that it comprises a bucket strainer for separating the secondary concentrated stock solution to the stock and the slurry component 4 or
5. The solid-liquid separation device according to 5 .