JPH0523201Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a gravity-type filtration device for superpurifying tap water, industrial water, and other liquids.

[Conventional technology]

Conventionally, in a gravity type tank, backwashing using water or a combination of water and air is required for the material layer in which suspended matter in the raw water is trapped during the filtering process.

As shown in, for example, Japanese Utility Model Publication No. 60-22964, etc., a gravity-type filtration device that facilitates backwashing of this material layer is constructed by attaching an overflow drain with an overflow wall to the gravity-type filtration layer. A communication pipe with a submerged opening is provided in the overflow drain to communicate with the overwater collection chamber at the lower part of the gravity type overflow tank, and this communication pipe is connected to an inverted U-shaped siphon forming pipe within the overflow drain. The reason,
At the time of backwashing the material layer, a system was devised in which a siphon is formed in the siphon-forming pipe by the water level difference, and the excess water in the overwater outflow drain is caused to flow back into the water collection chamber, thereby backwashing the material layer. .

At the same time, a system was also devised in which the communication pipe was bent upward in the overflow drain to open it submerged in water, and the open end was loosely inserted into a cylinder (box-like body) whose upper end was closed. .

[The problem that the idea attempts to solve]

By the way, when backwashing a material layer, it is necessary to change the amount of backwash water when backwashing with water and when backwashing with a combination of water and air, and the amount of backwash water also changes depending on the amount of turbidity trapped in the material layer. Furthermore, it is also necessary to change the amount of backwash water depending on seasonal changes in water temperature.

However, in the above-mentioned Japanese Utility Model Publication No. 60-22964, etc., the amount of backwash water is always constant, and the amount of water cannot be changed depending on the situation.

The purpose of the present invention is to provide a gravity-type filtration device that allows superfluous water in a superfluous outflow conduit to be backwashed into a material layer during backwashing, and that allows the amount of water to be freely adjusted to a desired amount. That is.

[Means for Solving the Problems] The present invention includes attaching an overflow drain having an overflow wall to the gravity overflow tank, and guiding overwater into the overwater outflow drain from the lower part of the gravity overflow tank. In a gravity-type filtration device provided with a communicating pipe, a plurality of water passage holes are bored near the end of the communicating pipe, and the communicating pipe is bent upward to extend the end of the communicating pipe below the top of the overflow wall. The end of the communication pipe was loosely inserted into a cylinder whose lower end extended below the water passage hole and whose upper end was closed, and an air supply pipe equipped with an air valve at the top of the cylinder was connected to an atmosphere release valve. This is a gravity-type filtration device characterized by the following.

[Effect]

In the present invention configured as described above, during overprocessing, the air valve is closed and the atmosphere release valve is opened to open the inside of the cylinder to the atmosphere, and superhydrous water from the lower part of the overtank passes through the communication pipe to the cylinder. The flow direction is changed downward as it reaches the overflow drain, overflows the overflow wall, and is guided to the required location.

When the water flow resistance of the overtank increases to a predetermined value while such filtration continues, the overtank is backwashed. That is, the over-process is stopped, the atmosphere release valve is closed, the air valve is opened and air is supplied from the air supply pipe into the cylinder, the water level inside the cylinder is lowered below the water passage hole of the communication pipe, and the air is released from the communication pipe. Prevents excess water from flowing back into the overtank and sufficiently lowers the water level in the overtank to a specified level. After that, by adjusting the air pressure supplied into the cylinder by adjusting the opening of the air valve, etc., and increasing the water level inside the cylinder as appropriate, the number of water passage holes (water passage area) that come into contact with water will change. The amount of backwash water flowing back from the water hole to the overtank via the communication pipe can be adjusted to a desired amount.

〔Example〕

An embodiment of the present invention will be described with reference to the drawings. In Fig. 1, reference numeral 1 denotes a gravity-type overtank, inside of which, in order from the top, there is a backwash drainage gutter 2, a material layer 3, and a water collection chamber. 4 is provided. An overwater outflow conduit 6 having an overflow wall 5 is adjacent to the outside of the overflow tank 1, and this overflow outflow conduit 6 and the water collection chamber 4 in the overflow tank 1 are connected to each other.
It is communicated with through a communication pipe 7.

A plurality of water holes 8 are bored near the opening end of the communication pipe 7 in the overflow drain 6, and the communication pipe 7 is bent upward so that the opening end is located below the top of the overflow wall 5. has been done. Further, the vicinity of the open end of the communication pipe 7 is loosely inserted into a cylinder 9 whose lower end extends downward from the water passage hole 8 and whose upper end is closed. An air supply pipe 12 equipped with a valve 11 is connected to the pipe 10, and an atmosphere release valve 13 is connected to the pipe 10.
are also connected.

During the overprocessing, the atmosphere release valve 13 is opened to open the inside of the cylinder 9 to the atmosphere, and the overwater that has passed through the material layer 3 in the overflow tank 1 is communicated from the water collection chamber 4. The water reaches the inside of the cylinder 9 through the pipe 7, flows out from the lower end of the cylinder 9 into the overflow drain 6, overflows the overflow wall 5, and is guided to a required location.

While this process continues, when the water flow resistance of the material layer 3 increases to a predetermined value due to the capture of suspended matter in the raw water, the process is stopped (the raw water tank 1
), close the atmosphere release valve 13, open the air valve 11 to supply air from the air supply pipe 12 into the cylinder 9, and adjust the water level in the cylinder 9 to the water hole of the communication pipe 7. Lower it to an appropriate position below the part 8, and drain the water in the excess tank 1 while preventing the excess water in the excess water outflow channel 6 from flowing back from the communication pipe 7 to the excess tank 1.
The water level in the overflow tank 1 is sufficiently lowered to a predetermined position below the backwash drainage gutter 2.

After the water level in the tank 1 has fallen sufficiently, the air pressure supplied to the cylinder body 9 is adjusted by adjusting the opening of the air valve 11, and the water level in the cylinder body 9 is adjusted so that it comes into contact with water. The number of water holes 8 is changed to adjust the amount of water flowing backward through the water holes 8. That is, by adjusting the water level in the cylinder body 9 using air pressure, a desired amount of backwash water can be obtained.

In addition, if the water passage hole 8 near the open end of the communication pipe 7 is made in the shape of a vertically long slit, as shown in FIG. 2, the amount of backwash water can be changed linearly. If the width is gradually decreased downward, it becomes easier to control small flow rates.

Further, by changing the diameter of the water passage hole 8, the control at a minute amount may be adjusted more accurately. For example, the pore diameter may be gradually reduced.

Further, in the embodiment described above, an example was shown in which the end of the communication tube 7 was opened, but it may be in a closed state.

[Effect of idea]

As described above, according to the present invention, when using overwater in the overflow drain as backwash water,
The water level inside the cylinder in the overflow drain can be arbitrarily adjusted using air pressure, and the amount of backwash water flowing back from the communication pipe can be freely changed, making it easy to obtain the optimal amount of backwash water required. It is possible.

[Brief explanation of the drawing]

FIGS. 1 and 2 are longitudinal sectional views of essential parts of the embodiment of the present invention during backwashing, respectively. 1... Over tank, 2... Backwash drain, 3... Material layer, 4... Water collection room, 5... Overflow wall, 6... Overflow drain, 7... Communication pipe, 8... ... Water hole, 9 ... Cylindrical body, 10 ... Pipe, 11 ... Air valve, 12 ... Air supply pipe, 13 ... Atmosphere release valve.

Claims (1)

[Scope of utility model registration request] In a gravity type filtration device, a gravity type overflow tank is provided with an overflow drain having an overflow wall, and a communication pipe for guiding overwater from a lower part of the gravity type overflow tank is provided in the overwater outflow conduit. A plurality of water passage holes are bored near the end of the pipe, and the communicating pipe is bent upward to position the communicating pipe end below the top of the overflow wall, so that the lower end of the communicating pipe is connected to the passage. 1. A gravity-type filtration device, characterized in that the air supply pipe is loosely inserted into a cylindrical body extending downward from a water hole and whose upper end is closed, and an air release valve is connected to an air supply pipe provided with an air valve at the top of the cylindrical body.