JP7846524B2 - Filter cleaning device, filtration device, and filter cleaning method - Google Patents

Description

This invention relates to a filter cleaning apparatus, a filtration apparatus, and a filter cleaning method.

When a filter filters a mixture of solids and liquids, the solids are filtered out and accumulate on the filter surface, reducing the permeability of the liquid. Therefore, filters are washed to remove the accumulated solids.

For example, Patent Document 1 describes a method of cleaning a filter by spraying raw water onto it as a washing solution to remove aggregated particles called cake from a mixture of suspended matter (called a slurry) and liquid when the mixture is filtered.

Japanese Patent Publication No. 2018-015699

As described in Patent Document 1, when raw water slurry is used as the washing solution, the washing solution itself contains suspended solids. Therefore, even after washing, suspended solids remain attached to the filter, resulting in poor washing efficiency.

Therefore, the objective of the present invention is to provide a filter cleaning apparatus, a filtration apparatus, and a filter cleaning method that reduce the amount of suspended solids adhering to the filter after cleaning, thereby improving cleaning efficiency.

As a result of diligent study on the above-mentioned problems, the inventors of the present invention have found that a filter cleaning device equipped with a cleaning liquid discharge means that discharges a cleaning liquid toward the filter, wherein by cleaning with a first cleaning liquid containing suspended solids and a second cleaning liquid with a low concentration of suspended solids, the amount of suspended solids adhering to the filter after cleaning can be reduced, and thus the present invention has been completed.
In other words, the present invention relates to the following filter cleaning apparatus, filtration apparatus, and filter cleaning method.

The filter cleaning apparatus of the present invention, which solves the above problems, is a filter cleaning apparatus equipped with a cleaning liquid discharge means that discharges cleaning liquid toward the filter, wherein the cleaning liquid uses a first cleaning liquid and a second cleaning liquid, the first cleaning liquid being raw water and the second cleaning liquid being a liquid with a lower concentration of suspended solids than raw water.
This filter cleaning device uses raw water as the first cleaning solution and is equipped with a cleaning solution discharge mechanism that uses a second cleaning solution with a lower concentration of suspended solids than the raw water. As a result, it has the effect of reducing suspended solids adhering to the filter more efficiently than cleaning the filter with raw water alone.

Furthermore, one embodiment of the filter cleaning apparatus of the present invention is characterized by comprising a control unit that discharges a second cleaning solution after discharging a first cleaning solution.
This filter cleaning device includes a control unit that discharges a second cleaning solution after discharging a first cleaning solution. This allows for cleaning with a solution with a lower concentration of suspended solids than raw water after cleaning with the first cleaning solution, resulting in a more efficient reduction of suspended solids adhering to the filter.

Furthermore, in one embodiment of the filter cleaning apparatus of the present invention, the discharge pressure for discharging the second cleaning solution is higher than the discharge pressure for discharging the first cleaning solution.
With this filter cleaning device, since the second cleaning solution contains less suspended solids compared to the raw water, even if the discharge pressure of the second cleaning solution is higher than that of the first cleaning solution, the risk of suspended solids colliding with and damaging the filter can be reduced. Therefore, the filter can be cleaned at a higher pressure, resulting in more efficient cleaning.

Furthermore, in one embodiment of the filter cleaning apparatus of the present invention, the second cleaning solution is characterized in that it is a filtrate obtained by filtering raw water.
According to this filter cleaning device, since the second cleaning solution is the filtrate obtained by filtering the raw water, there is no need to supply the second cleaning solution from an external source.

Furthermore, one embodiment of the filter cleaning apparatus of the present invention is characterized in that the raw water is wastewater.
With this filter cleaning device, since the raw water is wastewater, it is possible to reduce suspended solids adhering to the filter more effectively than when cleaning the filter with wastewater alone, resulting in more efficient cleaning.

Furthermore, one embodiment of the filtration apparatus of the present invention is characterized by comprising a filter cleaning device according to any one of claims 1 to 5 and a filter.
This filtration device uses raw water as the first washing solution and is equipped with a washing solution discharge mechanism that washes with a solution with a lower concentration of suspended solids than the raw water as the second washing solution. As a result, it has the effect of reducing suspended solids adhering to the filter more efficiently than washing the filter with raw water alone.

Furthermore, one embodiment of the filter cleaning method of the present invention is a filter cleaning method in which a cleaning solution is discharged toward the filter, wherein the cleaning solution uses a first cleaning solution and a second cleaning solution, the first cleaning solution being raw water, and the second cleaning solution being a solution with a lower concentration of suspended solids than raw water.
This filter cleaning method uses raw water as the first cleaning solution and a second cleaning solution with a lower concentration of suspended solids than the raw water. As a result, it has the effect of efficiently reducing suspended solids adhering to the filter compared to cleaning the filter with raw water alone.

According to the present invention, it is possible to provide a filter cleaning apparatus, a filtration apparatus, and a filter cleaning method that reduce the amount of suspended solids adhering to the filter after cleaning, thereby improving cleaning efficiency.

This is a schematic diagram showing the configuration of a filtration device according to the first embodiment of the present invention. This is a schematic diagram showing the configuration of a filtration device according to a second embodiment of the present invention. This is a schematic diagram showing the configuration of a modified filtration device according to a second embodiment of the present invention. This is a schematic diagram showing the configuration of a filtration device according to a third embodiment of the present invention.

The following describes preferred embodiments of the present invention with reference to the drawings. The filter cleaning method of the present invention will be replaced by the following description of the configuration and operation of the filter cleaning apparatus. Furthermore, this embodiment is not limiting to the present invention.

[First Embodiment]
Figure 1 is a schematic diagram showing the configuration of a filtration device 1A equipped with a filter cleaning device 2A and a filter 4 according to a first embodiment of the present invention.
In this embodiment, the filtration device 1A filters raw water 3 containing liquid and suspended solids using a filter 4, separating the raw water 3 into suspended solids and a filtrate 5 having a lower concentration of suspended solids than the raw water.

(raw water)
The raw water 3 to be filtered is a mixture containing liquid and suspended solids. The raw water 3 can be any mixture, not just a slurry in which solids are mixed with liquid. Examples include factory wastewater, river water, sewage, drinking water, and food processing plant wastewater. Furthermore, the liquid used for filtration in drinking water or water production can be used as the raw water. Additionally, the liquid used for filtration in the manufacture of pharmaceuticals, cosmetics, beverages, or food products can also be used as the raw water.

More specifically, this includes drainage from tunnel sites, ready-mix concrete plants for spraying, dice slime recovery drainage, batching plant drainage, river construction dry pit drainage, deep foundation construction drainage, grout construction drainage, shield construction drainage, shield excess slurry, dredging and landfill drainage, caisson construction drainage, cast-in-place pile drainage, floor cleaning drainage, wellpoint construction drainage, foundation construction yard drainage, tire cleaning drainage, core boring drainage, diamond cutter drainage, soil contamination excavation yard drainage, VOC decomposition and cleaning drainage, incinerator dismantling and cleaning drainage, radioactive decontamination construction drainage, wire saw cutting construction drainage, water jet cutting construction drainage, paper mill process drainage, pulp mill process drainage, food factory cleaning drainage, ready-mix concrete plant cleaning drainage, concrete secondary product factory drainage, and crushed stone plant yard drainage. Examples of wastewater include: scrubber wastewater, gas washing wastewater, waste incinerator quenching tower wastewater, converter gas washing wastewater, arc furnace gas washing wastewater, silver recovery process wastewater, sand washing equipment wastewater, water washing neutralization wastewater, barrel polishing wastewater, electropolishing wastewater, glass polishing wastewater, wet blasting wastewater, spray painting booth wastewater, cationic coating wastewater, stainless steel pickling wastewater, raw material yard wastewater, raw material conveyor cleaning wastewater, wet dust recovery wastewater, factory yard wastewater, continuous casting wastewater, rolling cooling wastewater, dehumidification drain wastewater, immersion cutting yard wastewater, slag yard wastewater, ship bottom bilge wastewater, shipbuilding dock wastewater, shellfish removal wastewater, cooling tower blowdown wastewater, dyeing factory wastewater, milk plant cleaning wastewater, tunnel wall cleaning wastewater, building exterior wall cleaning wastewater, car wash wastewater, golf course wastewater, industrial disposal site leachate, and the like.
In this embodiment, we will explain using the case of barrel polishing wastewater containing oil and suspended solids generated in the bearing manufacturing process as an example.

Examples of barrel polishing wastewater from raw water 3 include wastewater from the initial polishing process, the finishing process, and the final finishing process. The states of raw water 3 and the filtered filtrate 5 are illustrated in Table 1 below.

(Filter cleaning device)
The filter cleaning device 2A comprises a filtration container 6, a cleaning liquid discharge means 7, a pump 8, a rotating mechanism 9, a raw water storage section 10, a filtrate storage section 11, piping 12 (lines L1 to L7), and a valve 13.
The filter cleaning device 2A, when cleaning the filter 4, discharges cleaning solution from the cleaning solution discharge means 7, and uses a first cleaning solution 31 (raw water 3) and a second cleaning solution 32 (filtrate 5) for cleaning. Furthermore, the filter cleaning device 2A is characterized by discharging the second cleaning solution 32 after discharging the first cleaning solution 31 to perform the cleaning.

<Filtering container>
The filtration container 6 is a sealed container having an internal space capable of housing the filter 4. The filtration container 6 can be of any shape or size as long as it allows the raw water 3 to pass through the filter 4 and be separated into suspended solids and filtrate 5. The filtration container 6 has a filtrate discharge section 61 and a waste liquid discharge section 62.

≪Filtrate discharge section≫
The filtrate discharge section 61 is a path through which raw water 3 is supplied to the internal space of the filtration container 6, and the filtrate 5 filtered by the filter 4 is discharged to the outside of the filtration container 6. It is a separate flow path to prevent the raw water 3 and the filtrate 5 from mixing.

≪Waste liquid discharge section≫
The wastewater discharge section 62 is a path for discharging the suspended solids filtered by the filter 4 from the internal space of the filter container 6. During filter cleaning, a concentrated mass (also called a cake) of suspended solids accumulated on the surface of the filter 4 is discharged from the wastewater discharge section 62 together with the first cleaning liquid 31 and the second cleaning liquid 32.

<Washing liquid dispensing means>
The cleaning solution dispensing means 7 dispenses the cleaning solution toward the filter 4. The cleaning solution used consists of a first cleaning solution 31 and a second cleaning solution 32. The cleaning solution dispensing means 7 is not particularly limited as long as it has a structure that can remove and clean the cake from the filter 4 by supplying the first cleaning solution 31 and the second cleaning solution 32 to the surface of the filter 4 at a constant pressure during filter cleaning.
The cleaning solution dispensing means 7 is positioned to remove the cake from the entire vertical surface of the filter 4.
In this embodiment, when filtering raw water 3, the cleaning solution is supplied to the internal space of the filter container 6 via the cleaning solution discharge means 7. In other words, the supply path of the first cleaning solution 31 is the same when filtering raw water 3 and when cleaning the filter.
While it is possible to have a structure in which separate paths are provided for supplying raw water 3 to the internal space of the filtration container 6 when filtering raw water 3, and for supplying the first cleaning solution 31 (raw water 3) to the cleaning solution discharge means 7 when cleaning the filter, the structure of the filtration container 6 is simplified by supplying both raw water 3 and the first cleaning solution 31 from the cleaning solution discharge means 7, as in this embodiment.

<Cleaning solution>
The cleaning solution 30 includes the first cleaning solution 31 and the second cleaning solution 32.
≪First Cleaning Solution≫
The first cleaning solution 31 is raw water 3, and during filter cleaning, the raw water 3 stored in the raw water storage unit 10 is used as the first cleaning solution 31.
≪Second Cleaning Solution≫
The second washing solution 32 is a liquid with a lower concentration of suspended solids than the raw water 3. Specifically, it can be the filtrate 5 obtained by filtering the raw water 3, industrial water, a mixture of raw water 3 and filtrate 5, or a mixture of industrial water and filtrate 5.
In the first embodiment of the present invention, during filter cleaning, the filtrate 5 stored in the filtrate storage section 11 is used as the second cleaning solution 32. By using the filtrate 5 obtained by filtering raw water 3 as the second cleaning solution 32, there is no need to supply cleaning solution from an external source.

<pump>
Pump 8 supplies raw water 3, first washing solution 31, and second washing solution 32 to the washing solution discharge means 7.
The type, size, and function of the pump 8 are not particularly limited, as long as it can supply the raw water 3, the first washing solution 31, and the second washing solution 32 to the internal space of the filtration container 6 via the washing solution discharge means 7.

<Rotation mechanism>
The rotating mechanism 9 is located outside the filtration container 6 and has the function of rotating the filter 4 in the circumferential direction.
The rotating mechanism 9 can specifically be a motor, but it is not particularly limited as long as it can rotate the filter 4 circumferentially within the internal space of the filtration container 6.
As the filter 4 is rotated by the rotating mechanism 9, the first cleaning solution 31 and the second cleaning solution 32 discharged from the cleaning solution discharge means 7 are evenly supplied to the entire circumferential surface of the filter 4, allowing the entire filter to be cleaned efficiently.

<Raw Water Storage Section>
The raw water storage unit 10 is a tank that stores the raw water 3 supplied from outside the filtration device 1A. The size and shape of the raw water storage unit 10 are not particularly limited, as long as it is capable of storing the raw water 3.
In this embodiment, the raw water storage unit 10 is supplied with cleaning wastewater containing cake discharged from the wastewater discharge unit 62. During filter cleaning, the cleaning wastewater of the first cleaning solution 31 or the second cleaning solution 32, which contains the cake after cleaning, is returned to the raw water storage unit 10 and supplied to the filtration container 6 as raw water 3 for circulation.

<Filtrate storage section>
The filtrate storage section 11 is a tank for storing the filtrate 5 filtered by the filtration device 1A. The shape and other characteristics of the filtrate storage section 11 are not particularly limited, as long as it is large enough to store the filtrate 5 and to secure the amount of the second cleaning solution 32 used when cleaning the filter.

<Piping>
The piping 12 connects the filtration container 6 and the raw water storage section 10 or filtrate storage section 11, and is a pipe for moving the raw water 3 or filtrate 5.
The piping 12A includes lines L1, L2, and L3. The piping 12A is a flow path connecting the raw water storage section 10 and the filtration container 6, and the filtrate storage section 11 and the filtration container 6, and is a pipe that supplies raw water 3, first washing liquid 31, and second washing liquid 32 to the washing liquid discharge means 7 of the filtration container 6.
Piping 12B includes lines L4, L5, and L6. Piping 12B is a flow path connecting the filtration container 6 to the filtrate storage section 11 and the filtration container 6 to the outside of the filtration device 1A (external process), and is a pipe for discharging the filtrate 5 to the filtrate storage section 11 or to the outside of the filtration device 1A.
The piping 12C is equipped with line L7 and is a flow path connecting the filtration container 6 and the raw water storage section 10, and is a pipe for supplying washing wastewater to the raw water storage section 10.

<valve>
Valve 13 is installed in piping 12A, piping 12B, and piping 12C. Valve 13 can have any structure as long as it can block or allow the raw water 3, filtrate 5, first washing liquid 31, or second washing liquid 32 to pass through, and may be opened and closed by human operation or by automatic control controlled by a control unit (not shown).
Valve 13 is used to switch the flow path between filtering raw water 3 with the filtration device 1A and cleaning the filter 4.
Valves 13A and 13B are located in piping 12A. Valves 13C and 13D are located in piping 12B. Valve 13E is located in piping 12C.

(Filter)
The filter 4 is not particularly limited as long as it is a filtration member capable of separating suspended solids and liquid from the raw water 3. However, the filter 4 of the filtration device 1A is particularly suitable for cases where a cleaning method called backwashing, which involves sending cleaning solution from the downstream side (the side where the liquid of the raw water 3 passes through the filter) to the upstream side (outside the filter) where the raw water 3 is supplied to clear clogging of the filter, is not applicable, or where backwashing does not have a cleaning effect. Specifically, a pleated filter, which is made by folding a flat filtration member multiple times to form pleats, can be mentioned.
In this embodiment, the filter 4 is a cylindrical pleated filter, and the suspended solids contained in the raw water 3 are concentrated on the outer surface of the filter 4, and the filtrate 5 passes through the inside of the filter 4.

(Regarding the operation of the filtration system)
Next, the operation of the filtration device 1A will be explained.
First, let's explain the process when filtering the raw water 3. In this process, valves 13A and 13C of the filtration device 1A are opened, and the other valves 13 are closed. As a result, the raw water 3 is supplied to the filtration container 6. This state is referred to as the filtration preparation step.

Then, the raw water 3 from the raw water storage unit 10 is supplied by the pump 8 to the washing liquid discharge means 7 via lines L1 and L3 of the piping 12A. The raw water 3 is supplied from the washing liquid discharge means 7 to the internal space of the filtration container 6. The suspended solids of the raw water 3 are concentrated on the outer surface of the filter 4 to form a cake, while the liquid from the raw water 3 that has passed through the filter 4 becomes the filtrate 5.

The filtrate 5 is stored in the filtrate storage section 11 via lines L4 and L5 of piping 12B from the filtrate discharge section 61. After a certain amount has been stored in the filtrate storage section 11, valve 13D is opened and valve 13C is closed, causing the filtrate 5 to be discharged to the next process outside the filtration device 1A via lines L4 and L6 of piping 12B. These processes constitute the filtration process.

The filter cleaning process is performed when the raw water 3 is filtered and the filter 4 becomes clogged, reducing the liquid flow rate of the raw water 3 to a certain level. The timing of the filter cleaning process can be determined by: installing a flow meter at any point in the piping 12 and checking when the flow rate in the piping 12 drops to a certain level; installing a pressure gauge at any point in the piping 12 and checking when the pressure in the piping 12 exceeds a certain pressure; measuring the time elapsed since the raw water 3 was processed; or visually inspecting the condition of the filter 4 by a person.

When the filter cleaning process is performed, valves 13A and 13E of the filtration device 1A are opened, and the other valves 13 are closed. Since valve 13E is open, the raw water 3 that filled the internal space of the filtration container 6 during the treatment of the raw water 3 is discharged.
Furthermore, the rotating mechanism 9 is activated, causing the filter 4 to rotate circumferentially. This state is considered the washing preparation step.

Once the cleaning preparation process is complete, the first cleaning solution 31 (raw water 3) is supplied by the pump 8 to the cleaning solution discharge means 7 via lines L1 and L3 of the piping 12A. This process is referred to as the first cleaning solution discharge process.
The first washing liquid 31 (raw water 3) is discharged from the washing liquid discharge means 7 toward the filter 4 in the internal space of the filtration container 6 and supplied so as to collide with the filter 4, thereby washing and removing the cake from the surface of the filter 4. The washing wastewater containing the first washing liquid 31 (raw water 3) and the cake is stored in the raw water storage section 10 via line L7 of the piping 12C.

Next, the filter 4 is washed with the first washing solution 31 to remove the cake, and then washed with the second washing solution 32.
The valve 13A of the filtration device 1A is closed, and the valve 13B is open.

In this state, the second cleaning solution 32 (filtrate 5) is supplied by the pump 8 to the cleaning solution discharge means 7 via lines L2 and L3 of the piping 12A. This process is referred to as the second cleaning solution discharge process.
The switching between the first cleaning fluid discharge process and the second cleaning fluid discharge process may be controlled by a control unit (not shown) or by human intervention.

The second cleaning solution 32 is discharged from the cleaning solution discharge means 7 toward the filter 4 in the internal space of the filtration container 6 and supplied so as to collide with the filter 4, thereby cleaning the surface of the filter 4. The filter 4 that has been cleaned with the first cleaning solution 31 has cake and suspended solids contained in the raw water 3, which is the first cleaning solution 31, adhering to the surface of the filter 4.
Therefore, by washing the filter 4 in that state with the second washing solution 32, cake and suspended matter adhering to the filter 4 can be washed away, thereby improving the cleaning efficiency of the filter 4.
Furthermore, since the second washing solution 32 has a lower concentration of suspended solids than the first washing solution 31 (raw water 3), even if the second washing solution (filtrate 5) collides with the filter during washing, it has the effect of suppressing damage to the filter 4 by suspended solids compared to the first washing solution 31.
The second washing solution 32 and the washing wastewater containing cake and suspended solids are stored in the raw water storage section 10 via line L7 of piping 12C.

The filter cleaning is completed with the above steps. The rotating mechanism 9 is stopped, and the valve 13 returns to the state where it filters the raw water 3, allowing the filtration process of the raw water 3 to be performed again.

[Second Embodiment]
Figure 2 is a schematic diagram showing the configuration of a filtration device 1B equipped with a filter cleaning device 2B according to a second embodiment of the present invention.
In the filtration apparatus 1B of the second embodiment of the present invention, the same reference numerals are used for the same functions and structures as in the first embodiment, and their descriptions are omitted.
The second embodiment of the present invention differs from the first embodiment in that, instead of the pump 8 of the first embodiment, a pump 81 for supplying the first cleaning liquid 31 to the cleaning liquid discharge means 7 and a pump 82 for supplying the second cleaning liquid 32 to the cleaning liquid discharge means 7 are provided separately. Furthermore, the discharge pressure of the second cleaning liquid 32 discharged from the cleaning liquid discharge means 7 is higher than the discharge pressure of the first cleaning liquid 31 discharged from the cleaning liquid discharge means 7.

<Pump 81>
The pump 81 is installed in line L1 of the piping 12A and supplies raw water 3 and the first washing liquid 31 to the washing liquid discharge means 7.
The pump 81 is not particularly limited in terms of type, size, or function, as long as it can supply raw water 3 or first washing liquid 31 to the internal space of the filtration container 6 via the washing liquid discharge means 7. However, a pump with a smaller flow rate than pump 82 or a pump controlled to have a smaller flow rate than pump 82 is used.

<Pump 82>
The pump 82 is installed in line L2 of the piping 12A and supplies the second cleaning liquid 32 to the cleaning liquid discharge means 7.
The pump 82 is not particularly limited in terms of type, size, or function, as long as it can supply the second cleaning liquid 32 to the internal space of the filtration container 6 via the cleaning liquid discharge means 7. However, a pump with a larger flow rate than pump 81 or a pump controlled to have a larger flow rate than pump 81 is used.

As described above, because the flow rate of pump 82 is greater than that of pump 81, the filter cleaning device 2B experiences a state where the discharge pressure of the second cleaning liquid 32 (filtrate 5) discharged from the cleaning liquid discharge means 7 is higher than the discharge pressure of the first cleaning liquid 31 (raw water 3) discharged from the cleaning liquid discharge means 7.

(Regarding the operation of filtration device 1B)
Next, the operation of the filtration device 1B will be described. The operation that is the same as that of the filtration device 1A in the first embodiment will be omitted from the description.
The operation when filtering raw water 3 is the same as that of the filtration device 1A in the first embodiment, and is also the same up to the cleaning preparation step in the filter cleaning process. Therefore, the explanation will focus on the steps from the cleaning preparation step onward.

Once the cleaning preparation process is complete, the first cleaning liquid 31 is supplied by the pump 81 to the cleaning liquid discharge means 7 via lines L1 and L3 of the piping 12A (first cleaning liquid discharge process).
The first cleaning solution 31 is discharged from the cleaning solution discharge means 7 toward the filter 4 in the internal space of the filtration container 6 and supplied so as to collide with the filter 4, thereby cleaning and removing the cake from the surface of the filter 4. The cleaning wastewater containing the first cleaning solution 31 and the cake is stored in the raw water storage section 10 via line L7 of the piping 12C.

Next, the filter 4 is cleaned with the first cleaning solution 31 to remove the cake, and then it is cleaned with the second cleaning solution 32.
The valve 13A of the filtration device 1A is closed, and the valve 13B is open.

In this state, the second cleaning liquid 32 is supplied by the pump 82 to the cleaning liquid discharge means 7 via lines L2 and L3 of the piping 12A (second cleaning liquid discharge step).
The switching between the first cleaning fluid discharge process and the second cleaning fluid discharge process may be controlled by a control unit (not shown) or by human intervention.

The second cleaning solution 32 is discharged from the cleaning solution discharge means 7 toward the filter 4 in the internal space of the filtration container 6 and supplied so as to collide with the filter 4, thereby cleaning the surface of the filter 4. The filter 4 that has been cleaned with the first cleaning solution 31 has cake and suspended solids contained in the raw water 3, which is the first cleaning solution 31, adhering to the surface of the filter 4.
At this time, the second cleaning liquid 32 discharged from the cleaning liquid discharge means 7 has a higher discharge pressure than the first cleaning liquid 31 discharged from the cleaning liquid discharge means 7. Therefore, cake and suspended matter adhering to the filter 4 can be washed away with the high-pressure second cleaning liquid 32, thereby increasing the cleaning efficiency of the filter 4.
Furthermore, since the second washing solution 32 has a lower concentration of suspended solids than the raw water 3, even if the second washing solution 32 collides with the filter at a higher pressure than the first washing solution 31 during washing, it can more effectively suppress damage to the filter 4 due to suspended solids compared to the first washing solution 31, and the washing time can be shortened because it can be washed at a higher pressure.
The second washing solution 32 and the washing wastewater containing cake and suspended solids are stored in the raw water storage section 10 via line L7 of piping 12C.

The filter cleaning is completed by the above operation. The rotation mechanism 9 is activated, and the valve 13 returns to the state where it filters the raw water 3, making it possible to filter the raw water again.

In the second embodiment of the present invention, a pump 81 and a pump 82 with a higher flow rate than pump 81 are provided separately, and an example is shown where the discharge pressure of the second cleaning liquid 32 discharged from the cleaning liquid discharge means 7 is higher than the discharge pressure of the first cleaning liquid 31 discharged from the cleaning liquid discharge means 7. However, as shown in the modified example of the second embodiment of the present invention in Figure 3, a pump 83 controlled by a control unit 84 may be installed in line L3 of piping 12A instead of the pump 8 of the first embodiment of the present invention, and the control unit 84 may control the flow rate of pump 83 to be greater during the second cleaning liquid discharge process than during the first cleaning liquid discharge process, so that the discharge pressure of the second cleaning liquid 32 discharged from the cleaning liquid discharge means 7 is higher than the discharge pressure of the first cleaning liquid 31 discharged from the cleaning liquid discharge means 7.

[Third Embodiment]
Figure 4 is a schematic diagram showing the configuration of a filtration device 1C equipped with a filter cleaning device 2C according to a third embodiment of the present invention.
In the third embodiment of the present invention, the same reference numerals are used for the same functions and structures as in the first embodiment, and their descriptions are omitted.
The third embodiment of the present invention differs from the first embodiment in that it separately provides a cleaning liquid discharge means 7A and a cleaning liquid discharge means 7B.

<Washing liquid dispensing means 7A>
The cleaning liquid dispensing means 7A dispenses the first cleaning liquid 31 toward the filter 4. The cleaning liquid dispensing means 7A is applicable as long as it has a discharge pressure that can remove the cake from the filter 4 and clean it by supplying the first cleaning liquid 31 to the surface of the filter 4 during filter cleaning.
<Washing liquid dispensing means 7B>
The cleaning liquid dispensing means 7B dispenses the second cleaning liquid 32 toward the filter 4. The cleaning liquid dispensing means 7B is applicable as long as it is structured in such a way that the cake on the filter 4 can be removed and cleaned by supplying the second cleaning liquid 32 to the surface of the filter 4 during filter cleaning.

The cleaning liquid dispensing means 7A and cleaning liquid dispensing means 7B share a pump 8. This configuration is applicable if, when the flow rate of the first cleaning liquid 31 supplied by pump 8 to cleaning liquid dispensing means 7A is the same as the flow rate of the second cleaning liquid 32 supplied by pump 8 to cleaning liquid dispensing means 7B, the discharge pressure of cleaning liquid dispensing means 7B dispensing the second cleaning liquid 32 is higher than the discharge pressure of cleaning liquid dispensing means 7A dispensing the first cleaning liquid 31. Specifically, an example of this configuration is to make the nozzle opening of cleaning liquid dispensing means 7B smaller than the nozzle opening of cleaning liquid dispensing means 7A.

<Piping>
The piping 12 is further equipped with line L8 in piping 12A. Line L8 is a pipe for supplying the second cleaning liquid 32 to the cleaning liquid discharge means 7B of the cleaning liquid discharge means 7.

<valve>
Valve 13 further comprises valve 13F and valve 13G.
Valve 13F is open during the filtration process and the first washing liquid discharge process, and closed during the second washing liquid discharge process.
Furthermore, valve 13G is closed during the filtration process and the first washing liquid discharge process, and open during the second washing liquid discharge process.

(Regarding the operation of filtration device 1C)
Next, the operation of the filtration device 1C will be described. The operation of the filtration device 1C is the same as that of the filtration device 1A in the first embodiment, and, as in the first embodiment, during the filtration process, the valve 13 is operated so that raw water 3 is supplied from the washing liquid discharge means 7. Specifically, in this embodiment, filtration is performed with valves 13F and 13G opened and closed so that raw water 3 is supplied from the washing liquid discharge means 7.
Furthermore, in the first cleaning fluid discharge process, the valve 13F on line L3 and the valve 13G on line L8 are switched so that the first cleaning fluid 31 is discharged from the cleaning fluid discharge means 7A, and the first cleaning fluid 31 is not discharged from the cleaning fluid discharge means 7B, and cleaning is performed.
Then, in the second cleaning fluid discharge step, the valve 13F on line L3 and the valve 13G on line L8 are switched so that the second cleaning fluid 32 is not discharged from the cleaning fluid discharge means 7A, but is discharged from the cleaning fluid discharge means 7B, and cleaning is performed.

In the filter cleaning of the filtration device 1C, the second cleaning solution 32 is supplied from the cleaning solution discharge means 7B, which has a high discharge pressure. Therefore, cakes and suspended substances adhering to the filter 4, which was cleaned with the first cleaning solution 31, can be washed away with the high-pressure second cleaning solution 32, thereby further improving the cleaning efficiency of the filter 4.

In the first to third embodiments, a rotating mechanism 9 is provided to rotate the filter 4, allowing for cleaning of the entire circumferential direction. However, by providing multiple cleaning liquid discharge means 7 circumferentially surrounding the filter 4, the need for the rotating mechanism 9 can be eliminated, allowing for cleaning of the entire circumferential direction of the filter 4.

Furthermore, in the first to third embodiments, pumps 8, 81, 82, and 83 are provided to supply the first cleaning liquid 31 or the second cleaning liquid 32 to the cleaning liquid discharge means 7, 7A, and 7B. However, it is also possible to install the raw water storage unit 10 and the filtrate storage unit 11 at a higher position than the installation positions of the cleaning liquid discharge means 7, 7A, and 7B, so that the first cleaning liquid 31 or the second cleaning liquid 32 falls by gravity and is supplied to the cleaning liquid discharge means 7, 7A, and 7B, thereby causing the first cleaning liquid 31 or the second cleaning liquid 32 to be discharged.

The filter cleaning apparatus, filtration apparatus, and filter cleaning method of the present invention can be used for factory wastewater, river water, sewage wastewater, drinking water wastewater, and wastewater from food processing plants. They can also be used in filtration devices during water production or water manufacturing, and in filtration devices used in the production of pharmaceuticals, cosmetics, beverages, or food products. Examples include filtering beverages or brewer's yeast.
In particular, because cleaning can be done at low cost by utilizing the filtrate, it is suitable for use in factory wastewater such as barrel polishing wastewater.

1A, 1B, 1C Filtration device; 2A, 2B, 2C Filter cleaning device; 3 Raw water; 4 Filter; 5 Filtrate; 6 Filtration container; 7, 7A, 7B Cleaning liquid discharge means; 8 Pump; 9 Rotating mechanism; 10 Raw water storage unit; 11 Filtrate storage unit; 12, 12A, 12B, 12C Piping; 13, 13A, 13B, 13C, 13D, 13E Valves; 31 First cleaning liquid; 32 Second cleaning liquid; 61 Filtrate discharge unit; 62 Waste liquid discharge unit; 81 Pump; 82 Pump; 83 Pump; 84 Control unit.

Claims (7)

A filter cleaning apparatus equipped with a cleaning liquid discharge means for cleaning the raw water side surface of a cylindrical filter by discharging the cleaning liquid so as to collide with the outer surface of the filter,
The aforementioned cleaning solution uses a first cleaning solution and a second cleaning solution.
The first washing solution is raw water, and the second washing solution is a solution with a lower concentration of suspended solids than the raw water.
A filter cleaning device characterized in that the flow path for discharging the first cleaning liquid and the second cleaning liquid is the same. The filter cleaning apparatus according to claim 1, characterized by comprising a control unit that discharges the second cleaning solution after discharging the first cleaning solution. The filter cleaning apparatus according to claim 1 or 2, characterized in that the discharge pressure for discharging the second cleaning solution is higher than the discharge pressure for discharging the first cleaning solution. The filter cleaning apparatus according to any one of claims 1 to 3, characterized in that the second cleaning solution is a filtrate obtained by filtering raw water. The filter cleaning apparatus according to any one of claims 1 to 4, characterized in that the raw water is wastewater. A filtration apparatus comprising a filter cleaning device according to any one of claims 1 to 5, and a filter. A filter cleaning method that cleans the raw water side surface of a cylindrical filter by discharging a cleaning solution so as to collide with the outer surface of the filter,
A filter cleaning method in which cleaning solution is discharged in the direction of the filter,
The aforementioned cleaning solution uses a first cleaning solution and a second cleaning solution.
The first washing solution is raw water, and the second washing solution is a solution with a lower concentration of suspended solids than the raw water.
A filter cleaning method characterized by discharging the first cleaning solution and the second cleaning solution from the same flow path.