JP2004183443A - Step screen - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a step screen reducing the quantity of wash water for dregs (screen slag). <P>SOLUTION: This step screen wherein movable screens and fixed screens having stair-like steps on the surface side to which raw water containing impurities flows, are alternately arranged maintaining prescribed spaces from one another, is constituted to move upward the impurities captured by the movement of the movable screen and provided with a washing water sprinkling means for sprinkling washing water toward the movable screens and fixed screens, above the water surface of the raw water of the movable screens and fixed screens and on the side to which the raw water flows. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a step screen, and more particularly to a step screen capable of cleaning contaminants captured by the step screen.
[0002]
[Prior art]
Conventionally, a bar screen is provided in a channel through which raw water such as sewage containing impurities (hereinafter, sewage will be described as an example), and impurities (screen residue) captured by the bar screen are removed. A screen that discharges by rake is known (see Non-Patent Document 1).
[0003]
In recent years, step screens as shown in FIGS. 2A to 2E have been proposed. In this step screen, a long movable screen and a fixed screen that perform a step-like step on the surface on which sewage flows are provided at a predetermined distance from each other and are inclined in a water channel in which raw water flows. Is configured. This will be further described with reference to FIGS. 2 (a) to 2 (e). FIG. 2 (a) is a view seen from the side wall of the water channel W through which the sewage flows, and shows the moving state of the foreign substance A captured by the step screen. It is a thing. The lower portion of the movable screen 1a and the fixed screen 1b of the step screen are located on the bottom surface W 'of the water channel W, and the upper portions thereof are inclined at a predetermined angle toward the direction in which the sewage flows. The movable screen 1a is configured to be moved (rotated) as indicated by arrows (1) to (4) in FIGS. 2B to 2E via a link mechanism (not shown). That is, as shown in FIG. 2A, the rotation of the movable screen 1b is changed from a state in which the movable screen 1a and the fixed screen 1b overlap each other to a surface having steps of the movable screen 1a (hereinafter referred to as a surface). Side protrudes from the surface of the fixed screen 1b in the direction in which the sewage flows, and in that state, rises to the height of one or more steps (see FIGS. 2B and 2C). It retracts from the surface of the fixed screen 1b (see FIG. 2D), and finally comes to the same position as in FIG. 2A, that is, the position where the movable screen 1a and the fixed screen 1b overlap. As described above, by the rotation of the movable screen 1a, the contaminant A captured at the step at the predetermined position on the fixed screen 1b moves to a step above the step at the predetermined position (FIG. 2 (b)). ) To (e), and is finally discharged from the upper end of the fixed screen 1b to a contaminant transport path (not shown).
[0004]
[Non-Patent Document 1] "Water Wastewater Handbook" edited by the Editorial Committee of Irrigation Wastewater Handbook, pp. 143 to 145, issued the 7th printing on April 25, 1990.
[Problems to be solved by the invention]
By the way, in the screen work in the sewage treatment, a large amount of washing water is attached to the residue, which is a trapped foreign matter, because a large amount of sand adheres and contaminants that are a source of offensive odor components also adhere. It is necessary to wash using. For such washing of the residue, a residue cleaning device as shown in Japanese Patent No. 3244719 of the present applicant is known. Since the load on the water treatment facility increases, it has been desired to reduce the amount of washing water as much as possible.
[0006]
SUMMARY OF THE INVENTION The present invention has been made to meet the above-mentioned demands, and an object of the present invention is to provide a step screen which requires a small amount of washing water for residue.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the step screen according to the present invention alternately moves a fixed screen and a movable screen having a step-like step on a surface side on which the raw water containing impurities flows, while maintaining a predetermined interval. A step screen arranged to move impurities trapped by the movement of the movable screen upward, wherein the movable screen and the fixed screen are on the side where the raw water flows above the water surface of the raw water. And washing water spraying means for spraying washing water toward the movable screen and the fixed screen.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1A is a front view of a step screen according to one embodiment when viewed from the surface, and FIG. 1B is an enlarged view of the screen when viewed from the side. The same components as those in FIGS. 2A to 2E will be described using the same reference numerals.
[0009]
This step screen is provided with the movable screens 1a and the fixed screens 1b alternately arranged at predetermined intervals over the entire width of the water channel W in which the sewage flows, similarly to the known step screens. In order to simplify the drawing, the screens 1a and 1b at the center of the water channel W are omitted.
[0010]
The lower portion of each of the screens 1a and 1b is located at the bottom surface W 'of the channel W, and the upper portion thereof is provided above the water surface of the channel W (see FIG. 1B). Each of the screens 1a and 1b has a step-like step on the surface side, and the upper portion of each of the screens 1a and 1b has a lower flow direction than the lower portion (see the arrow in FIG. 1B). It is positioned and inclined at a predetermined angle. Further, as described with reference to FIGS. 2A to 2E, the movable screen 1a is configured to move (turn) via a link mechanism (not shown). Therefore, the contaminants (residues) c captured by the fixed screen 1b can be moved upward.
[0011]
The contaminants discharged from the upper end of the fixed screen 1b are washed through a moving mechanism such as a belt conveyor (not shown) by the above-described applicant's Patent No. 3244719, and the like. Disposal such as incineration and landfill is performed.
[0012]
In the figure, reference numeral 10 denotes a water spray pipe corresponding to the washing water spraying means of the present invention. The sprinkling pipe 10 is provided above the surface side of each of the screens 1a and 1b and above the water surface of the water channel W. The sprinkling pipe 10 is configured to be supplied with pressurized water from a pump (not shown) via a valve V. As the pressure water, intermediate water in the water channel W after the step screen processing (water approximately at the middle of the water depth of the water channel W) can be used. Further, it can be treated water of a sedimentation basin corresponding to a post-processing device of this step screen.
[0013]
Although not shown, the sprinkling pipe 10 is provided with a large number of small holes opened on the surface side of each of the screens 1a and 1b. Therefore, the washing water is sprayed from the small holes to the impurities A captured by the respective screens 1a and 1b, and the impurities can be washed. The contaminants A trapped in the screens 1a and 1b are trapped in a stable state, that is, in a state of being in close contact with the screens 1a and 1b. There is no danger of passing or passing through the openings of the screen, and the contaminants a can be efficiently washed. In addition, if the washing water is sprayed on the contaminants scraped up by the bar screen rake, the contaminants fall from the rake or pass through the screen openings, so that the contaminants on the bar screen rake are removed. Can not be sprinkled.
[0014]
As described above, since the impurities are washed in the step screen, it is not necessary to wash the impurities (residue) thereafter, and even if necessary, the amount of the washing water can be reduced. .
[0015]
【The invention's effect】
The step screen according to the present invention is configured such that a movable screen and a fixed screen having step-like steps are alternately arranged at a predetermined interval from each other on a surface on which raw water containing impurities flows, and the movable screen is movable. A step screen adapted to move contaminants trapped upward by the movable screen and the fixed screen, on the side where the raw water flows, above the water surface of the raw water of the movable screen and the fixed screen. Since the washing water spraying means for spraying washing water is provided, impurities are washed on the step screen, and subsequent washing of impurities (residues) becomes unnecessary, and even if necessary, washing is performed. The effect of reducing the amount of water is obtained.
[Brief description of the drawings]
FIG. 1A is a front view of a step screen viewed from the front side, and FIG. 1B is an enlarged view of the screen viewed from the side.
FIGS. 2A to 2E are explanatory views showing the principle of movement of contaminants captured by a step screen.
[Explanation of symbols]
W Waterway W 'Bottom surface 1a Movable screen 1b Fixed screen 10 Watering pipe (washing water spraying means)
V Balbuy Impurities

Claims (1)

A movable screen having a step-like step and a fixed screen are alternately arranged at a predetermined interval on the side where the raw water containing impurities flows, and the impurities captured by the movement of the movable screen are moved upward. A step screen to be moved,
Washing water spraying means for spraying washing water toward the movable screen and the fixed screen is provided on the side where the raw water flows, above the surface of the raw water of the movable screen and the fixed screen. Step screen.

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