JPS6022964Y2 - gravity filtration device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a gravity filtration device that performs air cleaning to filter and purify tap water, industrial water, and other water.

Normally, in a gravity-type filtration tank that performs air cleaning, the water level in the tank must be lowered sufficiently below the top of the backwash drain gutter before cleaning the air in the furnace material layer, otherwise the introduced air will cause the water surface to expand. However, there is a drawback that the furnace material in a fluid state flows out into the backwash drainage gutter, causing loss of the furnace material.

Conventionally, for this purpose, special operations have been carried out by attaching mechanical and electrical control devices to air cleaning, but these devices are expensive and have many problems in terms of handling.

The present invention aims to accurately eliminate these conventional drawbacks, and allows the water level to reach a predetermined level without using any mechanical or electrical control or special operations when cleaning the air of furnace materials. The object of the present invention is to provide a device that can lower the furnace material and accurately prevent the outflow of the furnace material.

The present invention is a gravity-type filtration tank equipped with an air cleaning mechanism, in which the tank is divided into a filtration chamber and a drain by a partition wall, and a furnace material layer is provided in the filtration chamber and a water collection chamber is provided below the filtration chamber. A backwash drain gutter is provided above the furnace material layer, and an intermediate drain pipe is provided between the backwash drain gutter and the furnace material layer, and the backwash drain gutter is connected to the furnace material layer through the partition wall. The present invention is characterized in that an opening communicates with the drain, and further, the water collection chamber and the filtered water outflow drain are communicated through a siphon-forming pipe equipped with a siphon breaker.

To explain one embodiment of the present invention with reference to the drawings, in FIG.
The filtration chamber 3 is partitioned into a drainage channel 4, and near the bottom of the filtration chamber 3, a water flow partition 5, such as a perforated plate or a net-like member, is provided, and a water collection chamber 6 is defined below the water flow partition 5. A furnace material layer 7 made of a supporting material and anthracite, sand, or other filtering material is provided on the upper part of the filter 5, and a backwash drainage gutter 8 is provided above the furnace material layer 7.

One end of the backwash drain gutter 8 is opened to the drain culvert 4 through the partition wall 2, and an intermediate drain valve 19 is provided between the backwash drain gutter 8' and the furnace material layer 7. A tube 15 is provided.

Further, a backwash drain pipe 16 equipped with a washing drain valve 20 is connected to the lower part of the drain 4, and the water collection chamber 6 is connected to an inverted U-shaped filtrate outflow pipe/backwash water pipe 9 (hereinafter referred to as (referred to as inverted U-shaped piping), and tank air cleaning pipe 2 equipped with an air cleaning valve 21
3 are arranged.

The inverted U-shaped pipe 9 is immersed in filtered water in the outflow conduit 22, and an air inflow and outflow pipe 10 equipped with an air inflow valve 11 for supplying pressurized air and an atmosphere release valve 12 is connected to the top of the pipe 9, Further, a raw water inflow pipe 14 equipped with a raw water inflow valve 18 is connected to the upper part of the tank body 1 .

In the figure, 13 is the outflow weir, 17 is the air cleaning pipe, 24.25,
26, 27, 28 and 29 are cylinders for operating each valve;
It is also possible to use a control system that is linked to a detection signal such as a timer or a water level detector so that automatic switching operation can be performed.

30 is an inflow weir.

Next, the operation procedure and operation of the above embodiment will be explained with reference to FIGS. 1 to 3.

(1) 'P passage process (see Figure 1) Raw water is introduced into the tank body 1 through the raw water inlet pipe 14, raw water inlet valve 18, and inlet weir 30, and while passing downward through the furnace material layer 7, the raw water is Suspended matter in the water is captured in the furnace material layer 7, and the filtered water passes through the water flow partition plate 5, reaches the water collection chamber 6, flows into the outflow culvert 22 through the inverted U-shaped piping 9, and flows out from the outflow weir 13. overflow.

As such filtration continues, the resistance of the furnace material layer 7 increases due to the trapped suspended solids, so the water level in the tank body 1 gradually rises and finally reaches near the top of the tank body 1.

At this time, the filtration operation is stopped and the furnace material layer 7 is backwashed.

During this filtration operation, the atmosphere release valve 12 may be open or closed, but all valves other than the raw water inlet valve 18 must be closed.

(2) Backwash process (2)-1 Preparatory operations (see Figure 2) Close the raw water inlet valve 18, intermediate drain valve 19 and washing drain valve 2
0 and the water level in the tank body 1 is lowered.

In this case, it is important to keep the water level in the filtration chamber 3 close to the connection position of the intermediate drain pipe 15 and to keep the water level in the outflow conduit 22 unchanged (maintaining the outflow conduit 22 in a full state). However, for this purpose, the following valve opening and closing operations are performed.

That is, when the water level in the tank body 1 falls to the water level A in the outflow culvert 22 (the height of the outflow weir 13) (during this period, the outflow culvert 22
(remains full), close the atmosphere release valve 12, open the air inflow valve 11, and pass the air inflow pipe 10 through the inverted U-shaped pipe 9.
By introducing pressurized air into the drain, the filtered water in the outflow conduit 22 is prevented from flowing back into the water collection chamber 6.

At this time, in the inverted U-shaped pipe 9, the filtered water sulfur input side pipe 9
' and the filtered water sulfur outlet pipe 9'' are temporarily at the same water level, but in order to completely prevent the backflow, it is necessary that H>h□ in Fig. 2, H<h2
(If H>h2, pressurized air flows out into the outflow conduit 22 and is wasted).

That is, the pressure P of pressurized air is p> (Po×ρht)
It is necessary that the value be P, and it is desirable that the value be P×(Po×ρh2).

However, Po is the atmospheric pressure and ρ is the density of the filtered water.

However, when the water level in the tank body 1 further falls and the water level in the filtration chamber 3 reaches the connection position of the intermediate drain pipe 15, that is, water level B, the outflow of water from the intermediate drain pipe 15 naturally stops; The water level in the filtrate inlet pipe 9' gradually decreases, and eventually the difference between the water level and the filtration chamber water level B becomes H, as shown in FIG.

This means that the pressurized air pressure inside the inverted U-shaped pipe 9 is (po + pH)
and atmospheric pressure P on the water surface in the filtration chamber 3.

This is because it is on.

In the above operation, the atmosphere release valve 12 may be closed first, the air inflow valve 11 may be opened, the raw water inflow valve 18 may be closed, and the intermediate drain valve 19 and the cleaning drain valve 20 may be opened.

In this case, the filtered water may temporarily flow up to the height of the air inflow valve 11, but this is not a problem at all.

Note that the cleaning drain valve 20 may be left open and the drain culvert 4 may be emptied.

(2)-2 Backwash operation (see Figure 3) When the water level in the filtration chamber 3 reaches B, the intermediate drain valve 19 is closed, and the air cleaning valve 21 is opened to drain air from the tank air cleaning pipe 23. When air is introduced, the air rises in the filtration chamber 3 through the water flow partition plate 5, and the furnace material layer 7 is fluidly stirred and cleaned.

During this air cleaning, the water surface expands due to the introduced air, but
Since the water level has already fallen sufficiently below the upper end of the backwash drain gutter 8, the expanded water level does not reach the upper end of the backwash drain gutter 8, and therefore the furnace material in a fluid state is stored in the backwash drain gutter 8 as before. It will not leak out.

After this air cleaning has been carried out for a certain period of time, the air cleaning valve 21
and close the air inflow valve 11, and the atmosphere release valve 12.
When the pressurized air in the inverted U-shaped pipe 9 is released into the atmosphere by opening the inverted U-shaped pipe 9, the filtered water in the outflow conduit 22 flows back through the inverted U-shaped pipe 9 due to the water pressure and flows into the filtration chamber 3. The filtered water rises through the water flow partition plate 5 and suspends the suspended solids separated from the furnace material by the air washing, and the waste water flows from the backwash drain gutter 8 into the drain culvert 4 and from the wash drain valve 20. It is discharged outside, allowing for efficient backwashing.

Note that after closing the intermediate drain valve 19, the air cleaning valve 21 is closed.
It will be clear from the above description that water backwashing and air backwashing can be performed simultaneously by opening the valve, closing the air inflow valve 11, and opening the atmosphere release valve 12.

(31p Resuming the filtration process After performing backwashing in this way for a certain period of time, the washing drain valve 20 and the air washing valve 21 are closed, the raw water inflow valve 18 is opened, and the filtration operation is resumed, thereby producing clear treated water. can be obtained easily.

In addition, in the present invention, instead of the above-mentioned inverted U-shaped piping, a fourth piping is used.
A structure as shown in the figure can also be applied.

In the figure, 31 is a box-shaped body. As described above, according to the present invention, the following advantages can be obtained.

■ In conventional gravity-type filtration tanks that perform air cleaning, when performing intermediate drainage, it was necessary to install a valve in the filtrate outflow pipe or the filtrate outflow pipe and backwash water pipe, and open and close it each time. However, there is an advantage that intermediate drainage can be performed without providing the filtrate outflow valve and the filtrate outflow/backwash valve.

In addition, the diameter of the filtrate outflow pipe and backwash water pipe is determined by the flow rate of the amount of backwash water, so the diameter of the valve for filtrate outflow and backwashing becomes large, and the above valve is automatically used only for intermediate drainage. Although it is uneconomical to use a valve, the device of the present invention does not require such a valve, so equipment costs can be reduced.

■ It is possible to prevent the loss of furnace material by lowering the water level to a predetermined position during air cleaning without requiring mechanical control or special operations, and its configuration is simple and inexpensive, and the filtration duration is short. The length allows stable operation without hindrance to filtration operations, and maintenance and safety are extremely simple.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention. Figure 1 is a front sectional view,
3 and 3 are explanatory diagrams of the operating procedure, and FIG. 4 is a partial front sectional view showing another embodiment of the siphon forming tube.

Claims (1)

[Scope of utility model registration request] In a gravity type filtration tank equipped with an air cleaning mechanism, the inside of the tank is divided into a filtration chamber and a drain by a partition wall, the filtration chamber is provided with a furnace material layer and a water collection chamber below it, and the furnace A backwash drain gutter is provided above the material layer, and an intermediate drain pipe is provided between the backwash drain gutter and the furnace material layer, and the backwash drain gutter is connected to the drain through the partition wall. A gravity type filtration device in which the water collection chamber and the filtrate outflow conduit are communicated through a siphon forming pipe provided with a siphon breaker.