JPH0239922B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an upflow filtration device equipped with an upflow type filtration tank used for tertiary treatment in sewage treatment plants.

(Prior Art) As shown in FIG. 3, the conventional upward flow filtration device as described above has a raw water flow path 52 provided above a filtration tank 51 in which a filtration layer 50 is formed, and a pressure regulating tank. 5
Raw water is supplied to the water supply pipe 54 connected to the water diversion device 67 at the bottom of the filtration tank 51 through 3, and the filtrate is discharged from the treatment waterway 55 at the top, and a large amount of suspended matter is trapped in the filtration layer 50. If the pressure drop increases, the cleaning water tank 56, large flow pump 57,
Usually, a small flow rate pump 58, which may be installed to meet the needs of the cleaning process, supplies cleaning water to the water supply pipe 54 while blowing air with a blower 59 to remove suspended solids from the filter medium.
However, such a conventional upward flow filtration device requires a large number of large-diameter automatic valves, and the pressure loss during cleaning is mainly due to the nozzle-type water division device 67, so two valves are usually used for cleaning. The disadvantages are that a series of large-capacity pumps are required, the equipment cost is high, and maintenance of these devices requires a great deal of effort.

(Problems to be solved by the invention) The present invention solves the conventional problems as described above,
The cleaning device for cleaning the filtration tank was completed with the aim of creating an upflow filtration device with a simple structure and easy maintenance.

(Means for Solving the Problems) The present invention provides a raw water channel at a position above an upflow type filter tank in which a filtration layer is formed on the top surface of a low pressure loss type water diversion device at the bottom of the tank. This raw water flow path is formed with a waterway for raw water that can be used as washing water with a water level of the same level, and an inflow siphon is installed in the raw water flow path to introduce the raw water into the water supply pipe at the bottom of the filtration tank. is characterized in that a cleaning siphon is provided for introducing cleaning water into the water supply pipe.

(Embodiment) Next, the present invention will be described in detail with reference to the illustrated embodiment. Reference numeral 1 denotes an upflow type filter tank, and inside thereof there are a support gravel layer 2, an upper gravel layer 3, and a sand layer 4.
A filtration layer 6 consisting of a sand layer 6, a grid 5 for preventing the sand layer from floating up, etc. are provided. 26 is filter tank 1
It is a low-pressure-loss water diversion device consisting of a perforated block installed at the bottom of the blower, and includes an air blow pipe 9 extending from the blower 8, a water supply pipe 10, and an air vent pipe 1.
1 is connected. On the other hand, above the filtration tank 1, a raw water channel 12 and a water channel 13 through which raw water, etc., which can be used as cleaning water and have a water level similar to that of the raw water channel 12, are formed.
An inflow siphon 14 is provided in the raw water channel 12 to introduce raw water into the water supply pipe 10 via a pressure regulating tank 15 and a raw water supply pipe 16. In addition, a cleaning siphon 17 is provided in the waterway 13.
The structure is such that raw water, etc. flowing through the pipe 3 can be introduced into the water supply pipe 10 via the washing water pipe 18. Further, as shown in FIG. 2, the cleaning siphon 17 is connected to the cleaning water pipe 1
8, the cleaning flow rate can be fixed. In addition, 19 is a drainage channel with a drainage siphon 20 provided on the upper side of the filter tank 1, and 21
22 is an automatic valve for operating each siphon; 23 is a wastewater pipe installed in the water supply pipe 10 at the bottom of the filtration tank 1; It is a water valve.

(Function) The upward flow filtration device of the present invention configured as described above supplies raw water from the raw water flow path 12 via the pressure regulating tank 15 to the water supply pipe 10 at the bottom of the filtration tank 1, and supplies the raw water into the tank. There is no difference from the conventional method in that turbidity is captured by the filter layer 6 and only the filtered water is taken out from the treatment channel 24. However, whereas the conventional device shown in FIG. 3 uses large-diameter automatic valves such as the raw water valve 62, washing valve 63, and drain door 64, the present invention uses a siphon pipe and small-diameter automatic valves. An inflow siphon 14, a cleaning siphon 17, a drainage siphon 20, etc., which are composed of an automatic valve and a vacuum source, are used, and since expensive large-diameter automatic valves are not required, equipment costs can be significantly reduced. In addition, when suspended matter gradually accumulates in the filtration layer 6 and the water flow pressure loss increases, the inflow siphon 14 is shut off to stop the inflow of raw water, and then the filtration layer 6 is washed. However, in the present invention, a low pressure loss type water diversion device 26 consisting of a perforated block, etc. is used, and conventionally, 5 to 10
Since the head of the washing water, which was previously required, can be reduced to about 3 m, washing can be performed using the washing water flowing down from the water channel 13, which has the same water level as the raw water channel 12, and the washing siphon Cleaning by gravity flow using No. 17 became possible. Therefore, whereas conventional devices usually require two series of large-capacity pumps, the present invention requires only the water channel 13 to be provided. Note that controlling the amount of washing water using the siphon can be easily performed by adjusting the degree of vacuum using the siphon operating valve 22. After such cleaning, the cleaning siphon 17 is shut off and the inflow siphon 14 is turned on to filter the raw water again.
If air bubbles for air blowing remain at the bottom of the tank, when these air bubbles rise, they may agitate the filter medium, peeling off suspended matter, and making the filtered water cloudy.
Conventionally, therefore, air is vented by connecting an air vent pipe 61 to an air blow pipe 60 that blows compressed air from a blower 59, but in this case, it is necessary to use a large diameter air vent pipe 61 and an air vent valve 66. be. On the other hand, when the pressure chamber 7 is formed at the bottom of the filtration tank 1 and air is vented from the pressure chamber 7 as in this embodiment, air accumulates at the ceiling of the pressure chamber 7, so the air vent pipe 11 There is no problem even if the diameter of the air vent valve 25 is small.

(Effects of the Invention) As is clear from the above description, the present invention uses a low-pressure-loss water diversion device in the filtration tank, thereby eliminating the need for high water pressure during cleaning.
A raw water channel and a channel for raw water that can be used as cleaning water are provided above the filtration tank, and not only the raw water but also the cleaning water is supplied through the siphon to the water supply pipe at the bottom of the filtration tank. It is not necessary to provide two lines of large-capacity pumps for supplying washing water as in the past, and therefore the device for washing the filter tank can be simplified. In addition, the present invention uses a siphon, which has low equipment costs and requires no maintenance work, instead of a large-diameter automatic valve that requires high equipment costs and requires a lot of maintenance work. Since we were able to omit the radial flow pump, we were able to significantly reduce the overall cost and make it nearly maintenance-free. Furthermore, in the present invention, since the water channel for washing water is made independent from the water channel for treated water, there is no change in the treated water in other filtration tanks during washing, and each filtration tank can be washed independently. There is also the advantage of being able to Therefore, the present invention can significantly contribute to the development of industry as it solves the problems of conventional upward flow filtration devices of this type.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is a sectional view showing a modification thereof, and FIG. 3 is a sectional view showing a conventional example. 1: Filter tank, 6: Filter layer, 10: Water supply pipe, 1
2: Raw water channel, 13: Water channel, 14: Inflow siphon, 17: Washing siphon, 26: Water diversion device.

Claims (1)

[Claims] 1 At the upper position of the upward flow type filtration tank 1 in which the filtration layer 6 is formed on the upper surface of the low pressure loss type water diversion device 26 at the bottom of the tank, there is a raw water flow path 12 and a water flow path of the same size as this raw water flow path 12. The raw water channel 12 is provided with an inflow siphon 14 for introducing the raw water into the water supply pipe 10 at the bottom of the filtration tank 1, and the water channel 13 is provided with a water channel 13 for carrying raw water that can be used as cleaning water. An upward flow filtration device characterized by being provided with a cleaning siphon 17 for introducing water into the water supply pipe 10.