JP4082971B2 - Scum crusher - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a scum crushing device that crushes scum generated in a water basin or the like of a settling basin of a sewage treatment plant.
[0002]
[Prior art]
In a diversion basin that distributes raw water to a settling basin of a sewage treatment plant, a scum layer is formed on the surface of the water by floating substances contained in the raw water. If the scum is mixed in the treated water without being removed in the sedimentation basin, the quality of the treated water is deteriorated. Therefore, the scum is removed as much as possible in the water conduit.
[0003]
The removal of the scum from the water culvert is carried out by a worker who regularly draws it with a handle or by the worker pulling the hose of the vacuum car.
[0004]
In order to automate the scum removal by the worker's manual operation as described above, the applicant of the present invention has previously described scum suction that can automatically remove scum in Japanese Patent Application Laid-Open Nos. 11-277056, 285686, and 285687. In addition to proposing an apparatus, Japanese Patent Application Laid-Open No. 11-290847 proposed a scum crushing apparatus that crushes the scum into small pieces so that the scum can be easily removed by suction.
[0005]
In the scum suction device according to the above proposal, the suction pipe moves up and down following the fluctuation of the water surface, and furthermore, the raw water and the scum can be effectively separated by the approach plate and the guide plate. It has the feature that it can be removed by suction. Moreover, the scum crushing apparatus according to the above proposal can crush the scum formed in a large film shape into small pieces by moving the three-dimensional object up and down to wave the water surface, so that the fluidity of the scum can be improved. Has features.
[0006]
[Problems to be solved by the invention]
As described above, when the scum crushing device according to the previous proposal is used, the scum is crushed into small pieces and easily fluidized, so that the scum can be automatically removed by the scum suction device according to the previous proposal. The scum crusher according to the previous proposal moves a three-dimensional object (container) of about 5 liters (L) up and down via a crank mechanism, generates a wave on the scum surface, and crushes the scum into small pieces. As a result, the mechanical structure is complicated, and the maintenance is troublesome. In addition, it has been desired that the scum broken into small pieces can be smoothly moved toward the discharge side of the scum.
[0007]
Accordingly, the present invention has been made to solve the above-described drawbacks, and an object of the present invention is to provide a scum crushing apparatus that can crush scum with a simple configuration and that can be easily maintained. . It is another object of the present invention to provide a scum crushing device in which crushed scum is smoothly moved in the scum pit direction.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the scum crusher according to the present invention is provided with an air outlet opening downward at the lower end of an air supply pipe vertically suspended in the raw water, and 50 air from the air outlet. to 5 liters once compressed air 500 kPa, floating comprising a 5 times to about ten times the compressed air supply control means Ru is intermittently ejected at a rate of 1 minute, air bubbles rises ejected on the surface of the water The scum is crushed by colliding with the scum layer.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a plan view showing the scum crushing apparatus according to the present invention with the cover removed when applied to a water trough of a settling basin (first settling basin or final settling basin) of a sewage treatment plant, and FIG. It is AA sectional view taken on the line of 1. FIG.
[0010]
The water conduit 1 is formed in the shape of an elongate channel provided on the upstream side of each of the sedimentation basins 2a to 2c so that raw water can be supplied to a plurality (three in the illustrated example) of the sedimentation basins 2a to 2c. And the raw | natural water in the water conduit 1 is comprised so that each of the sedimentation basins 2a-2c may be supplied via the inflow doors 3a-3c, respectively.
[0011]
In the figure, 10a to 10c are air supply pipes provided in the water conduit 1, and are provided at a predetermined interval along the water flow of the water conduit 1 (see arrow A in the water conduit 1). Yes. The installation intervals of the air supply pipes 10a to 10c are not uniform depending on the width of the water conduit 1, the speed of the water flow in the water conduit 1, the quality of the raw water (scum characteristics), etc. It is provided at intervals of 5 to 10 m.
[0012]
Each of the air supply pipes 10a to 10c is connected to the header pipe 11 via valves Va to Vc formed of automatic valves (solenoid valves), respectively. And the front end side (the front end side opposite to the side connected to the header pipe 11) of these air supply pipes 10a to 10c is below the water surface so as to be under the scum layer formed in the water conduit 1. They are provided so as to be located at 200 to 300 mm, respectively, and their tip ends are open and formed at the jet ports 12a to 12c, respectively. Each of the air supply pipes 10a to 10c extends vertically below the water surface, and the lower end is opened downward.
[0013]
The header pipe 11 is connected to a compressed air source (not shown). As this compressed air source, it can be shared with the compressed air source for the aeration tank of the sewage treatment plant. Of course, a compressor or blower for a scum crusher may be prepared and used as a compressed air source. However, since the sewage treatment plant is provided with a compressed air supply facility for the aeration tank, if it is shared with the compressed air for the existing aeration tank, a compressed air source can be easily obtained at low cost. .
[0014]
1 and 2, C is a controller composed of a programmable controller, and is configured to be able to control the valves Va to Vc intermittently, that is, intermittently (ON, OFF). Intermittent open / close control of each valve Va to Vc is not uniform due to the nature of the scum, etc. However, when 5 L of 500 to 50 kpa of compressed air is performed at least 5 times per minute, most of the scum is broken into small pieces. Can be crushed into pieces. If the number of times per minute is increased, the crushing effect is further increased. However, the intermittent opening / closing control of the valves Va to Vc involves mechanical difficulties when performed more than 10 times per minute. The intermittent opening / closing of the valves Va to Vc is preferably about 5 to 10 times per minute. Moreover, although it is also possible to supply compressed air continuously from the jet nozzles 12a-12c, if air is supplied continuously, the compressed air source becomes a large facility and the running cost is increased. Since new problems occur, the supply of compressed air is performed intermittently.
[0015]
3 shows air supply pipes 10a to 10c (in the example shown, the air supply pipe 10a. Since the air supply pipes 10b and 10c are also the same as the air supply pipe 10a, the air supply pipe 10a will be described below as an example). The state when the scum S when compressed air is supplied from is crushed is shown. That is, when the valve Va is opened, compressed air is supplied into the water conduit 1 from the outlet 12a of the air supply pipe 10a. Then, the supplied compressed air rises in the form of bubbles and lifts the scum S, and the scum S formed in a large film shape is crushed into small pieces by the lifting force.
[0016]
In the illustrated example, spout 12a~12c are you are open downward. As in Figure shown, when opening the spout 12a~12c downward, since dispersion of air bubbles is expanded, it is possible to crush a wide range of scum.
[0017]
Moreover, in the above-mentioned example, the spouts 12a-12c maintain a predetermined space | interval along the flow of the raw water of the water conduit 1, and the water channel width (length of the direction orthogonal to the flow direction of raw water) of the water conduit 1 In the above, only one is provided at the approximate center, but a plurality may be provided at predetermined intervals in the channel width direction. Further, the spouts can be provided evenly at predetermined intervals so as to be staggered when the water conduit 1 is viewed from the plane.
[0018]
In the figure, 20 is a scum removal mechanism provided at the downstream end of the water conduit 1. This scum removing mechanism 20 is proposed by the present applicant in Japanese Patent Application Laid-Open No. 11-277056. The scum removing mechanism 20 collects the flowing scum on the side of the suction pipe 22 with the abutment plate 21 and water and scum with the guide plate 23. And can be separated. Moreover, these are comprised so that it can follow the fluctuating water level. Therefore, the scum flowing on the water flow can be sucked through the notch 24 provided on the raw water inflow side of the suction pipe 22. Although not shown in the drawing, since the water level is located in the notch 24, the scum can be efficiently sucked and removed in a high concentration state.
[0019]
As the scum removing mechanism 20, a well-known scum removing mechanism such as a pipe skimmer can also be adopted without depending on the above-described suction pipe type. However, in sewage treatment facilities such as water diversions, there is a problem such as pipe skimmers being submerged, so the scum removing part (opening part) such as the above-described suction pipe type or movable dam scum pit Is preferably a scum removing device capable of following the water level.
[0020]
In the above-described example, the compressed air is discharged from the jet nozzles 12a to 12c, the rising bubbles collide with the scum layer, and the scum is repeatedly lifted and broken into pieces. A mixture of liquid and gas may be dropped and collided with the scum, and the scum may be broken into pieces. That is, the spouts 12a to 12c are provided at a height higher than the position of the scum S, and a part of the raw water or a part of the water (raw water) in the water conduit 1 is dropped toward the scum S from the spouts 12a to 12c. You may make it make it.
[0021]
FIG. 4 is a plan view when a scum crushing apparatus according to another embodiment of the present invention is applied to a water tank 1 of a settling basin similar to FIG. In addition to the above-described scum crushing means including the jet nozzles 12a to 12c and the like, the water conduit 1 is provided with spray means for promoting the movement of the scum S toward the scum removing mechanism 20 side. . The spray means is configured by providing spray ports (nozzles) 30a to 30c below pressure water supply pipes 32a to 32c having valves 31a to 31c, respectively, and connecting a header pipe 33 to the pressure water supply pipes 32a to 32c. Yes.
[0022]
Although not shown, the header pipe 33 is connected to a pump, and is configured to be supplied with pressure water via the pump. As the pressure water supplied to the header pipe 33, treated water of the settling basins 2a to 2c and water prepared separately can be used, but the intermediate water of the water conduit 1 can be circulated and used. When the intermediate water of the water conduit is circulated, the load on the settling basins 2a to 2c is not increased, which is preferable.
[0023]
Since each spray port 30a-30c is the same structure, the movement effect | action of the scum S is demonstrated using FIG. 5 for the spray port 30a as an example. The spray port 30a is on the upper side (above) of the formation surface of the scum S on the downstream side of the ejection port 12a and the ejection direction of the pressure water faces the scum removal mechanism 20, that is, the ejection direction of the pressure water. Is provided so as to be in the moving direction of the scum S crushed by the rising bubbles from the jet nozzle 12a (see the arrow of the flow of raw water in FIG. 5). The height of the spray port 30a from the surface on which the scum S is formed can increase the moving force the closer to the scum S, but taking into account fluctuations up and down the surface on which the scum S is formed (up and down fluctuations in the raw water). Can be decided.
[0024]
When the pressure water is ejected from the spray port 30a, the movement of the scum S after being crushed into pieces by the pressure water is promoted, and the scum S is smoothly and promptly moved to the scum removing mechanism 20 side. Can move. Since the spray port 30a is provided on the downstream side of the jet port 12a, the movement of the crushed scum S is significantly promoted as compared to the case where the spray port 30a is provided on the upstream side of the jet port 12a.
[0025]
In the above-described example, the spray port 30a is provided on the upper side of the scum S. However, the spray port 30a may be provided on the same surface as the scum S or on the lower side, but the upper side of the scum S is as described above. The scum S can be moved smoothly. Furthermore, although pressure water was used as the fluid to be ejected from the spray port 30a, compressed air or a mixture of air and liquid can be used, but pressure water can provide a stronger moving force.
[0026]
In the above example, the scum crusher is applied as a water basin for a sewage treatment plant, but is not limited thereto, and may be a sedimentation basin or the like. In particular, this scum crusher can be applied to a sewage treatment facility and other water treatment facilities where a scum scraping device such as a mechanical scraper provided with blades on an endless chain conveyor cannot be installed.
[0027]
【The invention's effect】
According to the present invention, the compressed air injected from the air injection port provided in the raw water rises as bubbles, since the collision ruptured scum layer that floats on the water surface, and scum is lifted repeatedly, It is surely crushed. In addition, if compressed air is continuously supplied, the compressed air source becomes a large facility and the running cost is increased. However, since the present invention intermittently supplies the compressed air, the running cost increases. Can be avoided. Since the facility only needs to vertically install an air supply pipe necessary for supplying compressed air from the compressed air supply source to the air jet outlet, both the facility cost and the operation cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a plan view when a scum crusher according to an embodiment of the present invention is applied to a water basin of a settling basin.
FIG. 2 is a cross-sectional view taken along line AA in FIG.
FIG. 3 is an explanatory view showing a scum crushing state.
FIG. 4 is a plan view when a scum crusher according to another embodiment of the present invention is applied to a water basin of a settling basin.
FIG. 5 is an explanatory diagram showing a scum crushing state and a moving state.
[Explanation of symbols]
1 Waterway 2a-2c Sedimentation basin (first sedimentation basin, final sedimentation basin)
3a-3c Inflow door 10a-10c Air supply pipe 11 Header pipe 12a-12c Outlet 20 Scum removal mechanism S Scum 30a-30c Spray port 31a-31c Valve 32a-32c Pressure water supply pipe

Claims (1)

An air outlet opening downward is provided at the lower end of an air supply pipe vertically suspended in the raw water, and 50 to 500 kpa of compressed air is supplied from the air outlet at a rate of 5 liters at a time and 5 times a minute. to comprise intermittently compressed air supply control means Ru is ejected at a rate of about 10 times, by colliding bubbles rises ejected in scum layer that floats on the water surface, and characterized by crushing the scum Scum crushing device.

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