JPS5854176Y2 - Washing device for mobile filtration equipment - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a device for cleaning filter media in a filtration device having a moving filter bed.

By removing the filter medium forming the filter bed in the filtration tank from the bottom of the tank, a filtration bed that moves within the tank is formed in the filtration tank.
In a moving filter bed filtration device in which a raw water supply part is provided in the L direction and a filtered water take-out part is provided at the bottom of the tank wall, the bottom of the liquid tank is usually formed in the shape of a cone with a downward convexity. The filter material extracted from the lower end of the filtration tank is circulated upward through the filtration tank using an air lift pipe installed upwards through the filtration tank, or an air lift pipe installed outside the filtration tank. It is designed so that it can be washed with a washing device at the upper part of the filtration tank before being returned to the upper part of the moving filter bed, and while performing the filtration operation while moving the filter bed. ,
It is also designed to allow cleaning of the filter medium.

However, if the filter media is simply washed during the filter media circulation process as described above, if the turbidity of the raw water becomes abnormally high, local clogging may occur and the filter media will not move. occurs, and a solution to such problems is required.

Therefore, even in the conventional filtration device as described above,
A backwashing device that can send backwash air and backwash water into the tank is attached, but if an air lift pipe for circulating filter media is located in the center of the filtration tank, the backwash air and backwash water can be sent into the tank. There is a problem that washed air and backwash water tend to blow up inside this air lift pipe, and even without such an air lift pipe, the filter medium easily flows in the center of the filtration tank and is therefore difficult to clog. Backwashing devices of the type that send backwash water and backwash air into the tank from the bottom have had the problem of not being able to fully demonstrate their effects.

This invention solves the above problems, and its gist is that in the above-mentioned moving filter bed filtration device, a At the very least, a backwash box is installed around the outside of the tank wall, and the backwash air supply pipe and backwash water supply pipe are connected to this backwash box, and the area covered by this backwash box is An appropriate number of backwash air inlets and backwash water inlets into the filtration tank are provided facing downward on the tank wall, and the opening position of the backwash air inlet in the filtration tank is set to The opening position of the backwash water inlet in the backwash box is located higher than the opening position of the backwash air inlet.

To explain the embodiment with reference to the drawings, the lower part of the filtration tank 1 is formed in a conical shape with a downward convergence, and the filter medium 2 filled on top
A moving filter bed is thus formed in the tank 1.

A sand extraction pipe 3 is connected to the tank bottom 1b formed as described above, but in the filtration device of this embodiment, the filter medium layer 2 is penetrated into the middle of the tank 1, and the contaminated sand is removed. A filter medium transfer pipe 4 is provided, and an air supply pipe 5 is opened below the transfer pipe 4, and the air ejected from the air supply pipe 5 into the transfer pipe 4 supplies the filtration tank. The filter medium 2 that has reached the bottom of the filter medium 2 is raised inside the transfer pipe 4 and is supplied to a filter medium cleaning device (not shown) disposed at the upper end thereof, where it is washed. The filter medium is allowed to fall and return onto the filter medium layer 2 by means of an umbrella-shaped dispersion plate 7.

8 is a raw water supply pipe connected to this filter tank 1, 9 is a treated water take-out pipe, and in the apparatus of this embodiment, the treated water take-out pipe 9 is connected to the lower part of the filter tank 1 formed in the lower part. A part of the wall is formed into a water collection screen 10, which is connected to a water collection chamber 11 formed on the outside. The filtration tank 1 is located outside the lower wall 1a of the filtration tank 1, which is formed in a hole, between the bottom of the tank and the water collection chamber 11, that is, located below the water collection chamber 11. A backwash box 12 is formed surrounding the outer periphery of the wall, and in this backwash box 12, as shown in FIG. 2, a backwash air supply pipe 13 and a backwash water supply pipe 14 are arranged above and below. The part of the wall of the filtration tank 1 surrounded by the backwash box 12 has
The following backwash air inlet 16 and backwash water inlet 17
An appropriate number of filters are provided surrounding the filter tank 1 and extending downward into the tank.

The opening position of the backwash air inlet 16 in the filtration tank 1 is located higher than the opening position of the backwash water inlet 17 in the filtration tank 1; The opening position of the backwash water inlet 17 in the backwash box 12 is located higher than the opening position in the backwash box 12 of the backwash air inflow [116]. [117 is knot-shaped 1
7a and projects upward into the backwash box 12.

Reference numeral 19 denotes an eaves provided at the L position of the inflow port 16 in order to allow the inflow port 16 of the backwash air to open substantially downward in the filtration tank 1.

Next, to explain the operation, the cleaning device according to this invention includes a backwashing box 12 arranged in the position as described above, and an inlet 16 formed in the positional relationship as described above. 17, it can be operated as follows.

That is, if the filter medium 2 is clogged and you want to clean it with air using the cleaning device of this invention, stop the filtration operation and then insert the backwash air into the backwash box 12 from the supply pipe 13. It is recommended to send backwash air.

Then, the water level in the backwash box 12 will be slightly higher than the opening color L1 in the tank of the backwash air inlet 16 (△P
The water level L2 is maintained at a low level L2, and the backwash air is fed into the filter tank 1 with equal pressure ΔP from each backwash air inlet 16, and the backwash action of the air is carried out. It will be done.

When this air washing is stopped, the pressure △P disappears and the liquid level inside the backwash box 12 reaches Ll, but the backwash water inlet 17 is connected to this liquid level inside the backwash box 12. Since it is located higher than L1, at this time, there is no possibility that the water in the filtration tank 1 will flow back into the backwash box 12 through the inlet 17.

In this regard, as illustrated in FIG. 3, if the opening color of the backwash water inlet 17' in the backwash box 12 is lower than the opening color of the backwash air inlet 16', , At this time, until the liquid level L2 in the backwashing box 12 returns to Ll during the air backwashing operation, from the time when the liquid level reaches the opening color L3 of the inlet 17', The filter medium 2 flows into the backwash box 12 through the inlet 17', but according to the present invention, such trouble does not occur.

In this way, when the air washing operation is performed, the liquid level in the backwash box 12 is stopped at Ll, and some air remains in the backwash box 12, but the liquid level is higher than the liquid level L1. After air washing, when the backwash water is sent into the backwash box 12 from the backwash water supply pipe 14, the air is pushed out through the nozzle 17a together with the backwash water, and the air is From the inlet 17, the backwash water is evenly distributed and forced into the tank.

Of course, it goes without saying that a portion of the backwash water is uniformly dispersed and flows into the tank from the backwash air inlet 16 as well.

In this way, the backwash air and backwash water are forced into the tank from a midpoint between the bottom of the tank and the water collection area, which solves the problem mentioned at the beginning, making it difficult for the filter media to flow. According to the cleaning device of this invention, even filter bed areas that are prone to clogging can be completely cleaned by backwashing air or backwashing water, or both, which are evenly sent around the lower part of the filtration tank. It is.

[Brief explanation of drawings]

Fig. 1 is a partially longitudinal front view showing an embodiment of a moving filter bed filtration device equipped with a washing device according to this invention, Fig. 2 is an enlarged view of its main parts, and Fig. 3 is similar to Fig. 2. It is a reference diagram showing the other side of the same part. 1...filter tank, 2...filter medium, 4...
... Filter medium transfer pipe, 5... Air supply pipe,
8... Raw water supply pipe, 9... Treated water take-out pipe, 11... Water collection room, 12... Backwash box, 13... ...Backwash air supply pipe, 14
... Backwash water supply pipe, 16 ... Backwash air inlet, 17 ... Backwash water inlet.

Claims (1)

[Scope of utility model registration request] The lower part of the filtration tank is formed into a corner, and a filter material extraction part is provided at the bottom of the tank, and a filter bed that moves within the tank is formed, and the moving filter bed is sandwiched and the upper part of the filter is removed. In a moving filter bed filtration device in which a raw water supply part is provided at the bottom of the tank wall and a filtered water takeout part is provided at the bottom of the tank wall, the tank bottom of the filtration tank and
A backwash box is provided around the outer periphery of the tank wall, located between the filtered water collection part, and a backwash air supply pipe and a backwash water supply pipe are connected to the backwash box. , An appropriate number of inflow ports for backwash air into the filtration tank and inflow ports for backwash water are provided facing downward on the tank wall in the area covered by this backwash box. The opening position of the washing air inlet is located higher than the opening position of the backwash water inlet, and the opening position of the backwash water inlet in the backwash box is higher than the opening position of the backwash air inlet. 1. A backwashing device characterized by being located at -L position.