JPH11239703A - Slow dirt-removing screen device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remove fine, soft and nonsolid floating dirt contained in sewage by a simple physical method. SOLUTION: Fine, soft and nonsolid floating dirt is caught by screens 3 separated and removed by providing a plurality of sheets of screens 3 with fine mesh width for the same flow rate and making the passing area to a plurality of times and gently reducing the velocity passing through the screens. Then, when dirt removing operation is continued for long time, refuse is stuck to the screen parts and passing resistance is gradually increased and a water level is slowly raised. An inflow port is closed by the signal of a high water level detector and a drain outlet 6 is opened to perform drainage. The front and the rear, the upper and lower parts of the screens are cleaned by a high- pressure water spray to remove dirt. After cleaning is finished, the drain outlet is closed an the inflow port is opened to again fill a tank with water and dirt- removing operation by the screens is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a primary treatment for removing polluted solids such as sewage, agricultural settlement drainage, and factory drainage, and belongs to the field of wastewater treatment.

[0002]

2. Description of the Related Art Conventionally, methods for removing polluted solid matter in wastewater include (1) a screen method,
There are (2) precipitation method, (3) flotation method, and (4) filtration method. The outline is as follows. (1) The screen method is mainly used for removing floating solids. (2) The sedimentation method removes sedimentary pollutants having a specific gravity larger than water. (3) The flotation method removes fine and floating contaminants. (4) The filtration method removes fine polluted solids.

[0003]

SUMMARY OF THE INVENTION The present invention does not carry out the primary treatment of sewage containing fine suspended pollutants by a sophisticated and complicated apparatus such as a flotation method or a filtration method.
An object of the present invention is to remove fine non-solid and soft floating contaminants using a simple and inexpensive apparatus.

[0004]

According to the present invention, an inflow port 2 and an outflow port 7 are provided in a water tank 1, and a screen 3 and a support plate 5 are alternately connected to a floor plate 4 in the water tank so as to be installed in a comb-like manner. Drainage ports 6 and 6a are provided on the storage tank 9 side and the treated water storage tank 10 side, respectively. A spray device 11 is provided at the top of the screen,
A water level H1 detector 8 is provided.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is constructed as described above. Raw water flows into a water tank 1 from an inlet 2 and a water level in the water tank is determined by an outlet 7. The contaminants are captured while flowing out of the outlet 7 as treated water. The relationship between the passing speed of the sewage passing through the screen and the removal efficiency is described. The passing rate of the pollutant increases as the passing speed increases. That is, non-solid soft contaminants pass through the screen at high flow rates. When the flow rate in the water tank is constant, the screen passing speed is inversely proportional to the area of the screen portion. That is, if the screen area is multiplied by a plurality of times, the passing speed is reduced to a multiple of one and the contaminant passing rate is reduced and the removal rate is improved. In addition, the width of the screen is reduced and the total area is increased so that the paper passes slowly, so that non-solid and soft floating properties such as finely divided paper fibers and soft vegetable waste are simultaneously formed with solid pollutants. It also captures contaminants and improves the removal rate.

Next, when the dust removing operation is continued for a long time, dust adheres to the screen portion, the passage resistance gradually increases, and the water level H1 gradually rises. The inflow port is closed by the high water level detector signal of H1, the drainage port 6 is opened and drained, and the high and low water sprays are used to wash the front and rear of the screen up and down to remove contaminants. After the washing is completed, the drainage port is closed. Open the inlet and fill again to clean the screen.

[0007]

1 is a plan view showing an embodiment of the present invention, and FIG. 2 is a sectional view. A plurality of screens 3 are supported in a water tank 1 by a support plate 5.
In addition, the screen area is alternately and vertically arranged in a comb shape to increase the screen area a plurality of times. Raw water flows in from the inlet 2 and stays on the raw water storage tank 9 side, reaches each screen 3, separates and removes polluted suspended matter while passing through the screen 3, is stored in the treated water storage tank 10, and is transferred from the outlet 7. Is done.

FIG. 3 shows a spray 1 for cleaning a screen device.
1 is an installation sectional view of FIG. When contaminants accumulate on the screen 3 and the passage resistance of the raw water increases, the water level H1 rises and reaches the high water level detector 8 to output a signal. With this signal, the inflow of raw water is interrupted, drain port 6 is opened to lower the water level in the tank,
The spray device is operated to remove the contaminants by the water stream.

[0009]

According to the present invention, when dust is removed using the screen device of the present invention, soft and non-solid floating contaminants can be efficiently removed together with solid contaminants, and fine contaminants removed by the flotation method. And non-solid contaminants which cannot be removed even by the flotation method can be removed at the same time.

[Brief description of the drawings]

FIG. 1 is an installation plan view of a screen device.

FIG. 2 is an installation sectional view of a screen device.

FIG. 3 is a sectional view of an installation of a screen cleaning spray device.

[Explanation of symbols]

 1 is a water tank 2, an inlet 3, a screen 4, a floor plate 5, a support plate 6, 6 a, a drain port 7, an outlet 8, a high water level detector 9, a raw water storage tank 10, a treatment The water storage tank 11 is a spray device

Claims (2)

[Claims] 1. A dust removing device having a rectangular water tank, one side having a sewage inflow port, the other end having an outflow port, and maintaining a water level, and a screen in the middle, in which a screen is provided with a plurality of surfaces to keep an interval. Slow dust removal screen, characterized in that the effective area of the screen is set to be multiple times with the front and back of the screen as the inflow water storage tank side and the treated water storage tank side, and the passing speed is reduced to capture and remove fine contaminants. apparatus. 2. A slow dust removing screen apparatus according to claim 1, wherein sprays are provided before and after the upper portion of each screen, and the screen is washed by operating a high pressure water spray.