JPS5831964B2 - How to clean the filter tank - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for cleaning an F filter tank in which the P material layer is made of sand, anthracite, or other granular materials, particularly fluidized backwashing in which the P layer is fluidized and cleaned.

Generally, when raw water is introduced into an r-filtration tank and passed through a granular f-material layer to obtain clear water, the turbidity contained in the raw water is captured in the e-material layer over time, increasing the swamp resistance. 1,
Eventually, it becomes impossible to overcome.

Therefore, the f-material layer must be cleaned after operation for a certain period of time.

Taking as an example a sand filter tank used for water treatment, etc., the cleaning of the door material layer involves backflow cleaning (backflow), in which the washing water is run in the opposite direction to that used during the P period, and cleaning of the surface of the R material layer (surface cleaning). Washing)
Normally, the amount of backwash water is 0.61'r? /lrt'”min
Before and after, surface washing water amount is 0.05 to 0.2 d/n? -min
It is.

The purpose of this backwashing is to fluidize the sand layer and remove the turbidity trapped within the sand layer, but the amount of backwash water is sufficient to fluidize the sand layer. be.

However, in order to further raise the discharged turbidity to the upper part of the fluidized sand, a large upward flow velocity is required, so the amount of backwash water is 0.6 m3/rr12 m
℃・ru, which is larger than the temperature at which the sand becomes fluidized.

Surface washing is performed by spraying pressurized water onto the surface of the sand layer to measure the collision and friction between sand grains, to prevent matte balls from occurring, and to enhance the cleaning effect.

Furthermore, conventionally, during backwashing, air was blown from the bottom of the swamp layer at the same time as backwash water to increase the cleaning effect. was often leaked.

SUMMARY OF THE INVENTION An object of the present invention is to provide a useful cleaning method that minimizes the amount of water used to clean the f-material layer and improves the cleaning effect.

The present invention provides an air blowing pipe which is installed above the expansion surface of the R material during backwashing of the R material layer in the backwashing of the slough material layer with washing water in a swell tank with granular materials as an F material layer. is arranged, and the suspended matter exfoliated on the expanded surface of the P material during the backwashing is transferred by the air and washing water blown from the air blowing pipe, and is discharged from the drain gutter provided at the upper part. This is a method of cleaning the tank.

In this case, the amount of backwash water is 0.3 to 0.4 n'? /7
? Z2・min is sufficient, and air is added to the upper part where the P material is fluidized and expanded at a rate of 0.3 to 0.577 Z'/rr?
・From the injection hole and □, the upper part of the fluidized P° material looks upward, and the backwash flow rate is 0.7 to 0.9 m3/rr.
?・Min, cleaning can be completed in a short time, and the generation of mud balls can be prevented.Furthermore, compared to the conventional backwashing method, which required an air pressure of 4 mAq, the method of the present invention can complete cleaning in a short time. Since it is blown onto the expanded surface during washing, a pressure of 0.5 to 0.7 mAq is sufficient, eliminating the outflow of the filter medium and allowing safe washing work.

Note that the air is dispersedly blown onto the expanding surface of the swamp material using a porous pipe, a nozzle, or the like.

An embodiment of the present invention will be described with reference to the drawings. 1 is a filtration tank, 2 is a washing water inflow pipe, 3 is an air blowing pipe provided above the expansion surface of the f-material in backwashing, and 4 is a spring material layer. , 5 is a drainage gutter.

In such a f overtank 1, the P material layer 4 becomes clogged,
In this case, the overflow operation is stopped and the P material layer 4 is cleaned.
The suspended matter trapped in the p-material layer 4 is peeled off and expelled onto the expanding surface of the sludge.

At this time, air is blown through the air blowing pipe 3, and the air and washing water push up and transport the turbidity that has been pushed onto the expanding surface of the P material, and the turbidity is discharged from the drainage gutter 5.

In the present invention, when the filtration layer is made of granular material as the F material layer, when the swamp material layer is backwashed with washing water, air is blown onto the expanded surface of the P material when the P material expands due to this backwashing. With a small amount of backwash water that is less than the amount of backwash water conventionally required for backwashing, contact and collision between door materials increases, turbidity can be easily separated, and the cleaning effect is increased, while the amount of backwash water is minimized. It has extremely useful advantages industrially, such as the fact that the air pressure used is low, and the specifications related to backwashing can be made extremely rational, making it possible to design an economical filtration tank. This method is used in combination with this method, and has the advantageous feature that it is guaranteed to be an effective fluidized backwash method and that operating costs can be greatly reduced.

[Brief explanation of drawings]

The drawing is a longitudinal sectional view showing an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Filter tank, 2... Washing water inflow pipe, 3... Air blowing pipe, 4... P material layer, 5... Drain gutter.

Claims (1)

[Scope of Claims] 1. When placing particulate matter in a slough tank with a P material layer and backwashing the P material layer with washing water, above the expansion surface of the swamp material during backwashing of the P material layer. Place the air blowing pipe,
Cleaning of a t-filter tank characterized in that during the backwashing, the suspended solids separated on the expanded surface of the swamp material are transferred by the air and cleaning water blown from the air blowing pipe and discharged from the drainage gutter provided at the upper part. Method. 2 The amount of backwash water for backwashing the swamp material layer is 0.3~
0.4rr'/rr?・The method for cleaning an f overtank according to claim 1, wherein the cleaning method is performed as min. 3 The amount of air blown onto the expanded surface of the p-material is 0.3~
0.577fl/? The cleaning method for a wastewater tank according to claim 1 or 2, wherein the cleaning method is performed at a rate of 722 min. 4 The air blown during the backwashing is 0.5 to 0.7 m.
A method for cleaning a slough tank according to claim 1, 2 or 3, wherein the cleaning method is carried out at a pressure of Aq.