JP3548938B2 - Filtration equipment - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a filtration facility provided in a water purification facility, and more particularly, a filter medium layer is supported by a lower water collecting device, and air introduced below the lower water collecting device is jetted into the filter medium layer to form a filter medium. The present invention relates to filtration equipment for performing air cleaning.
[0002]
[Prior art]
As a filtration facility such as a settling basin, a lower water collecting device provided with a number of water holes and water collecting nozzles was laid at the bottom of the filter tank, and the lower water collecting device supported a filter medium such as gravel, sand, and activated carbon. Structures are known. Usually, in the filtration equipment having such a structure, inflow water is introduced from above the filter medium layer, and treated water after filtration is drawn out from below the lower water collecting device. The washing of the filter media is performed by introducing compressed air below the lower water collecting device and blowing air from the water holes and water collecting nozzles into the filter media layer to perform air cleaning. Washing water is introduced into the filter medium layer, and the washing water is raised from below into the filter medium layer to perform water washing, and solid matter trapped in the filter medium is discharged from a trough provided above the filter medium layer. Like that.
[0003]
[Problems to be solved by the invention]
As described above, in the case of performing the water cleaning after performing the air cleaning, if the cleaning air is switched to the water cleaning and the cleaning air remains below the lower water collecting device even after the water level reaches the trough, the air is cleaned. The filter medium is blown out into the filter medium layer at the pressure described above, so that the filter medium is sowed up.
[0004]
Accordingly, the present invention provides a filtration facility having an exhaust structure capable of quickly and surely exhausting the cleaning air below the lower water collecting device when switching from air washing to water washing and suppressing outflow of the filter medium. It is intended to provide.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the filtration equipment of the present invention is a filtration equipment that performs air washing of a filter medium by introducing air below a lower water collecting apparatus that supports a filter medium layer. The exhaust pipe for discharging the air remaining in the pipe is disposed so that the uppermost part of the pipe inner surface is at least as high as the lower surface of the lower water collecting device.
[0006]
Further, the lower water collecting device is provided in the vicinity of the lower end of the pipe portion penetrating the floor plate, a strainer provided on the upper surface of the floor plate of the pipe portion, and a pipe portion penetrating the floor plate. And a water collecting nozzle having a vertical slit and a through-hole provided above the slit. Further, a guide groove for air discharge is provided on the lower surface of the lower water collecting device, and the uppermost portion of the inner surface of the exhaust pipe is arranged to be at least one level higher than the uppermost surface portion of the guide groove. Further, the exhaust pipe also serves as an inlet pipe for cleaning air.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in more detail with reference to the drawings. FIG. 1 is a cross-sectional front view showing an example of the filtration equipment of the present invention, FIG. 2 is a bottom view of a lower water collecting device, FIG. 3 is a cross-sectional front view of a main part, FIG. FIG. 3 is a partial cross-sectional front view illustrating an example of a nozzle.
[0008]
In the filtration equipment shown in this embodiment, a plurality of floor plates 3 constituting a lower water collecting device 2 are laid horizontally by supporting legs 4 at a predetermined height position at the bottom of a filtration tank 1, and gravel is formed on the upper surface thereof. In addition to supporting a filter medium 5 such as sand or activated carbon, a space serving as a treated water drainage section 6 is formed below the filter medium 5.
[0009]
Further, an inflow pipe 7 and a trough 8 are provided above the filtration tank 1, and a drain pipe 9, which serves both for deriving treated water and introducing cleaning water, is provided at the bottom of the treated water drain section 6. At the uppermost part of the treated water drainage section 6, air pipes 10, which serve both as a cleaning air introduction pipe and a cleaning air discharge pipe, are provided through the tank side walls, respectively.
[0010]
On the lower surface of the lower water collecting device 2, an air discharge guide groove 11 connected to the air pipe 10 is provided. The air discharge guide groove 11 is provided at a connection portion between the floor plates 3 and 3 and is formed in a semicircular shape having substantially the same diameter as the inner diameter of the air pipe 10. The positional relationship between the upper portion and the uppermost surface portion of the air discharge guide groove 11 is set so that the upper surface and the uppermost surface portion are flush with each other.
[0011]
As shown in FIG. 5, a large number of water collecting nozzles 12 provided on each floor plate 3 are provided on a pipe body 13 vertically penetrating the floor plate 3 and on a top surface of the floor plate of the tube body 13. And a vertical slit 15 provided near the lower end of the tubular body 13 below the floor plate 3, and a through hole 16 provided above the slit 15. The opening 14 is formed so that the filter medium 5 does not pass through. The water collecting nozzle 12 has a function of equalizing the amount of air ejected from each water collecting nozzle 12 at the time of air cleaning by the slit 15 and the through hole 16.
[0012]
In the filtration equipment having such a configuration, a normal filtration operation is a treatment in which the inflow water flows from the inflow pipe 7 into the tank as a downward flow, and flows down to the treated water drainage section 6 through the filter medium 5 and the water collection nozzle 12. This is performed by extracting water from the drain pipe 9. The washing of the filter medium 5 is performed by stopping the introduction of inflow water from the inflow pipe 7, introducing cleaning air of a predetermined pressure from the air pipe 10 to perform air cleaning, and then introducing cleaning water from the drain pipe 9 to remove water. This is performed by washing (backwashing).
[0013]
In the air cleaning, the air that has flowed into the treated water drainage unit 6 from the air pipe 10 is jetted into the filter medium 5 through the water collecting nozzle 12. At this time, most of the air flows into the pipe body 13 from the through hole 16 of the water collecting nozzle 12, and the remaining air pushes down the water surface in the treated water drainage unit 6 at the pressure, and the water surface descends. It flows into the tube body 13 from the opened lower slit 15. Then, since the amount of depression of the water surface in the treated water drainage unit 6 and the amount of air flowing into the tube unit 13 from the slit 15 are in a balanced state, the levels of the water collecting nozzles 12 are made uniform. Thus, the amount of air ejected from each water collecting nozzle 12 into the filter medium 5 can be made constant, and uniform air cleaning can be performed. In addition, even when there is a slight level difference, a substantially uniform ejection amount can be obtained. Further, even when a level difference that does not reach the slit 15 occurs partially, most of the air flowing from the upper through hole 16 is removed. Since the water is reliably ejected from the water collecting nozzle 12 into the filter medium 5, the entire filter medium 4 can be sufficiently washed with air.
[0014]
After performing the air washing, the washing water is caused to flow into the treated water drainage unit 6 from the drainage pipe 9, and the air remaining in the treated water drainage unit 6 is extruded and discharged from the air pipe 10 by the inflowing water. As described above, when the residual air is discharged by the inflow water, the residual air is flush with the uppermost part of the treated water drainage part 6, that is, the uppermost part of the air discharge guide groove 11 provided on the lower surface of the lower water collecting device 2. Since the air pipe 10 is disposed in the processing water drainage section 6, almost all of the air in the treated water drain section 6 can be discharged from the air pipe 10. In particular, by providing the air discharge guide groove 11, the air far from the air pipe 10 can flow toward the air pipe 10 through the air discharge guide groove 11. Air can be quickly and reliably discharged.
[0015]
Thereby, when performing the water washing, the air does not spout into the filter medium 5 together with the washing water, so that the filter medium 5 can be prevented from rising and flowing out of the trough 8. Further, at the time of air cleaning, the air pipe 10 is provided at the uppermost part of the treated water drainage section 6 and does not sink in the water and does not foam. The air layer (air mat layer) formed below the device 2 is not disturbed, and the air blowing state can be made uniform. Further, since the drain pipe 9 is provided at the bottom of the treated water drain section 6, the air mat layer is not disturbed when the washing water flows.
[0016]
The piping configuration and the arrangement of valves for performing air cleaning and water cleaning can be the same as those of this type of conventional equipment, and detailed description and illustration thereof are omitted. The present invention can also be applied to a lower water collecting device provided with a large number of water holes without providing a water collecting nozzle. Further, the present invention can be applied to both downward filtration and upward filtration, and can also be applied to a system that performs simultaneous cleaning by supplying air and water at the same time during air cleaning.
[0017]
【The invention's effect】
As described above, according to the filtration equipment of the present invention, the air remaining below the lower water collecting device can be quickly and reliably discharged when the process shifts from air washing to water washing (backwashing). Therefore, it is possible to prevent the air from being spouted into the filter medium together with the washing water, so that the filter medium is sowed and flown out of the trough.
[Brief description of the drawings]
FIG. 1 is a cross-sectional front view showing an example of the filtration equipment of the present invention.
FIG. 2 is a bottom view of the lower water collecting device.
FIG. 3 is a sectional front view of a main part.
FIG. 4 is a sectional side view of the same.
FIG. 5 is a partially sectional front view showing an example of a water collecting nozzle.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Filtration tank, 2 ... Lower water collecting device, 3 ... Floor plate, 4 ... Support leg, 5 ... Filter medium, 6 ... Treated water drainage part, 7 ... Inflow pipe, 8 ... Trough, 9 ... Drain pipe, 10 ... Air piping , 11: guide groove for air discharge, 12: water collecting nozzle

Claims (4)

In a filtration facility that performs air cleaning of a filter medium by introducing air below the lower water collecting device that supports the filter medium layer, an exhaust pipe that discharges air remaining below the lower water collecting device after the air cleaning is provided on the inner surface of the pipe. Filtration equipment characterized in that the upper part is arranged so as to be at least as high as the lower surface of the lower water collecting device. The lower water collecting device includes a pipe portion vertically penetrating the floor plate, a strainer provided on an upper surface portion of the floor plate of the pipe portion, and a vertical portion provided near a lower end of the pipe portion penetrating the floor plate. The filtration equipment according to claim 1, further comprising a water collecting nozzle having a slit in the direction and a through hole provided above the slit. A guide groove for air discharge is provided on the lower surface of the lower water collecting device, and the uppermost portion of the inner surface of the exhaust pipe is disposed so as to be at least one level higher than the uppermost surface portion of the guide groove. The filtration equipment according to claim 1, wherein The filtration equipment according to claim 1, wherein the exhaust pipe also serves as an inflow pipe for cleaning air.

Images