JPH0532164Y2 - - 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, sewage, 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 the backwashing of this material layer is constructed by attaching an overwater outflow channel having an overflow wall to the overflow tank, and A communication pipe with a submerged opening is installed in the outflow conduit to communicate with the superfluous water collection chamber at the lower part of the gravity-type overflow tank, and this communication pipe is formed into an inverted U-shaped siphon-forming pipe within the overwater outflow conduit. A system has been devised in which a siphon is formed in the siphon-forming pipe by the water level difference when backwashing the material layer, and excess water in the overflow drain is caused to flow back into the water collection chamber to backwash the material layer. Ta.

[The problem that the idea aims 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 to solve the problem]

The present invention provides a gravity-type filtration device in which a gravity-type overflow tank is attached with an overwater outflow conduit having an overflow wall, and a communication pipe is provided in the overflow outflow conduit to guide overwater from the lower part of the gravity-type overflow tank. In this step, the communicating pipe is bent and extended upward to close the upper end, and an air supply pipe having an air valve at the top of the communicating pipe is connected to an atmosphere release valve, and the communicating pipe is further communicated with the inside of the overwater outflow conduit. This gravity type filtration device is characterized in that a cylindrical body is loosely inserted, the upper end of the cylindrical body is positioned below the top of the overflow wall, and a plurality of water passage holes are bored in the cylindrical body.

[Effect]

In the present invention configured as described above, the air valve is closed and the atmosphere release valve is opened to open the inside of the communication pipe to the atmosphere during the filtration process, and the excess water from the lower part of the furnace tank is transferred from the communication pipe to the cylindrical body. It reaches the overflow drain through
It overflows the overflow wall and is guided to the required location.

While such filtration continues, when the water flow resistance of the furnace material layer increases to a predetermined value, the filtration tank is backwashed. That is, the over-process is stopped, the atmosphere release valve is closed, the air valve is opened to supply air from the air supply pipe into the communication pipe, and the water level in the communication pipe is lowered below the water passage hole of the cylinder body, and then 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 to the communication pipe by adjusting the opening of the air valve, etc., and increasing the water level in the communication pipe appropriately, the number of water passage holes (water passage area) in the cylinder that comes into contact with water can be increased. In other words, the amount of backwash water that flows back to the overflow tank via the overflow drain → cylinder → water hole → communication pipe can be adjusted to a desired amount.

In this way, the backwash water that flows back from the overflow drain to the overflow tank flows from inside the cylinder under the water surface through the water passage hole and into the communication pipe, and the flow is smooth and does not involve the air in the communication pipe. , the accuracy of the flow rate is increased, making it possible to accurately obtain the optimal amount of backwash water.

〔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.

The communication pipe 7 is bent and extended upward to close its upper end, and an air valve 9 is connected to the top of the communication pipe 7 via a pipe 8.
An air supply pipe 10 equipped with an air supply pipe 10 is connected to the pipe 8, and an atmosphere release valve 11 is also connected to the pipe 8.

Furthermore, a cylindrical body 12 that communicates with the inside of the overwater outflow conduit 6 and is bent upward is loosely inserted into the communication pipe 7.
The upper end of this cylindrical body 12 is located below the top of the overflow wall 5, and a plurality of water passage holes 13 are bored in the cylindrical body 12. These water holes 13 are connected to the cylindrical body 12.
This is preferably provided in the upper part of the.

During overprocessing, the atmosphere release valve 11 is opened to open the inside of the communication pipe 7 to the atmosphere, and the overwater that has passed through the material layer 3 in the overflow tank 1 is transferred to the water collection chamber 4.
From there, through the communication pipe 7 and the cylindrical body 12, the excess water drains into the drain 6.
It flows out into the interior, overflows the overflow wall 5, and is guided to the 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 11 , open the air valve 9 to supply air from the air supply pipe 10 into the communication pipe 7 , and adjust the water level in the communication pipe 7 to the water hole in the cylinder 12 . 13 to an appropriate position below the overwater outflow conduit 6 to prevent the overwater in the overflow drain 6 from flowing back from the communication pipe 7 to the overtank 1, drain the water in the overtank 1, and drain the overflow tank 1. The water level is sufficiently lowered to a predetermined position below the backwash drain gutter 2.

After the water level in the tank 1 has fallen sufficiently, the air pressure supplied to the communication pipe 7 is adjusted by adjusting the opening of the air valve 9, and the water level in the communication pipe 7 is adjusted so that it comes into contact with water. The number of water passage holes 13 is changed to adjust the amount of water flowing back through the overflow drain 6 → water passage hole 13 → communication pipe 7 → overtank 1. That is, by adjusting the water level in the communication pipe 7 using air pressure, a desired amount of backwash water can be obtained.

Note that if the water passage hole 13 formed in the cylinder body 12 is formed into a vertically long slit shape as shown in FIG. 2, the amount of backwash water can be changed linearly, and the width of the slit shape can be changed linearly. If the flow rate is gradually decreased downward, it becomes easier to control a small flow rate.

Further, by changing the hole diameter of the water passage hole 13, control at a minute amount may be adjusted more accurately. For example, the pore diameter may be gradually reduced.

Further, the upper end of the cylindrical body 12 may be open or closed.

[Effects of the invention] As described above, according to the invention, when using overwater in the overflow drain as backwash water,
To arbitrarily adjust the water level in a communicating pipe in an overwater outflow conduit using air pressure, to smooth the flow of backwash water flowing from the overwater outflow conduit through a cylindrical body into the communication pipe, and to freely change the amount of water. This makes it possible to accurately and easily obtain the optimum amount of backwash water required.

[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... ...pipe, 9 ... air valve, 10 ... air supply pipe, 11 ... atmosphere release valve,
12... Cylindrical body, 13... Water hole.

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. The pipe is bent and extended upward to close the upper end, and an air supply pipe equipped with an air valve at the top of the communication pipe is connected to an atmosphere release valve, and a cylindrical body that communicates with the inside of the overwater outflow conduit is placed in the communication pipe. 1. A gravity type filtration device, characterized in that the cylindrical body is loosely inserted, the upper end of the cylindrical body is positioned below the top of the overflow wall, and a plurality of water passage holes are bored in the cylindrical body.