JPH0730153Y2 - Solid sedimentation prevention device for sewage tank - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a means for preventing solids from settling in a wastewater tank such as an adjusting tank of a wastewater treatment facility.

[Conventional technology]

The wastewater tank in the wastewater treatment facility is a liquid tank that performs neutralization of wastewater or flocculation of suspended solid particles with a coagulant, and is also a mass transfer tank that moves the solid matter obtained by the treatment directly to the next step. A stirring device is provided for accelerating the reaction of the additive and for preventing the precipitation of the solid product.

For example, the adjusting tank 35 shown in FIG. 4 has a motor 36 at the top and an agitator 39 in which a rotary stirring blade 38 is attached to the lower end of a rotary shaft 37 held in the tank and is held by a pedestal 40 attached to the tank. A stirring tank having a withdrawal valve 41 at the bottom of the tank, which receives and stores sewage 42 containing fine floating solid particles in this adjusting tank 35, adds a polymer flocculant, and stirs the floating solid particles. Turn into flock. The treated sewage water 42 is appropriately extracted from the extraction valve 41 while preventing the solid matter from settling, the water content is separated by a filtering device such as a filter press, and the solid content is discarded or incinerated.

As the stirring device used in such a mass transfer tank that requires prevention of sedimentation of solids, in addition to the rotary stirring blade method as described above, a stirring method without a stirring blade is attached to the tank wall portion. There is also a system in which the jet water flow from the jet port is repeatedly circulated and circulated, or a system in which gas is blown from the jet port attached to the bath wall portion.

[Problems to be solved by the device]

However, in the case of the rotary stirring blade type stirring device, a rotary stirring speed of a certain value or more commensurate with the specific gravity of the solid particles to be mixed is required, and if the solid is more than the balance with the driving force of the motor. When the specific gravity of the particles becomes large, solid particles settle and accumulate on the bottom of the tank, which impedes the rotation of the stirring blade and damages the motor or the stirring blade.Therefore, a larger drive motor is required and normal operation is required. There was a problem that the stirring blade was easily damaged even at times. Further, the former jet water jet type device that does not use a rotary stirring blade has a large facility scale and significantly large driving power, and the latter gas jet type device cannot be expected to have a strong stirring effect. There was a problem.

Therefore, in view of such a situation, the present invention can perform sufficient agitation with a small amount of power to prevent the settling of the mixed solid particles, and the settling and accumulation of the solid particles as in the stirring blade method can damage the parts. It is an object of the present invention to provide a solid settling prevention device for a wastewater tank, which can be easily dealt with according to the situation of the wastewater tank, without the fear of causing the above.

[Means for Solving the Problems]

In order to achieve the above object, the present invention provides a blast mechanism for converting compressed gas accumulated in a pressure vessel into a gust of wind, and a blast mechanism held in a waste water tank, the upper end of which communicates with an ejection port of the blast mechanism and the lower end of which is described above. The pipe is formed in the lower part of the waste water tank and opens in a predetermined direction, and the pipe is provided with an opening valve near the upper end to open the inside to the outside, and by repeating the discharge / return operation of water in the pipe. The present invention proposes a solid matter settling prevention device for a sewage tank that prevents settling of solid matter in the sewage tank.

[Action]

Water is stored at the same level as in the waste water tank through the lower end opening of the pipe of the stirring device installed in the waste water tank.

When compressed air is accumulated in the pressure vessel of the blast mechanism and released rapidly, this compressed air becomes a gust of wind and rapidly presses and pushes down the water surface in the pipe from the ejection port, and water is directed in a predetermined direction from the opening at the lower end of the pipe. Discharge as a torrent. Next, when the open valve at the upper part of the pipe is opened, the air in the pipe communicates with the outside air, so that the water in the dirty water tank is naturally sucked into the pipe from the opening at the lower end of the pipe and returns.

By repeating the above operation, the inside of the waste water tank is agitated by inertial movement. The automatic repetition of the above operation is easily possible by general sequence control means.

In addition to the blast mechanism, by adjusting the diameter of the pipe and the opening of the lower end of the pipe, the discharge amount, discharge speed or direction of the pipe can be changed, sufficient stirring can be performed according to the situation of the waste water tank and the treated water, and the sedimentation of solid matter. Prevention is achieved.

A basic blast mechanism for converting the compressed base material accumulated in the pressure vessel into gust is known from Japanese Patent Publication No. 53-46484 (Patent No. 96626).

〔Example〕

The solid sedimentation prevention device for a waste water tank according to the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of an adjusting tank provided with a solid matter settling prevention apparatus according to the first embodiment of the present invention, FIG. 2 is a sectional view of a main part of a blast mechanism in the solid matter settling prevention apparatus of FIG. 1, and FIG. FIG. 4 is a cross-sectional view of a wastewater pitch provided with a solid matter sedimentation prevention device according to a second embodiment of the present invention.

In FIG. 1, reference numeral 1 is a circular adjusting tank in a wastewater treatment apparatus made of a stainless steel plate, and a withdrawal valve 2 is provided at the center of the inverted conical tank bottom. In this adjusting tank 1, a solid matter settling prevention device 3 is held by a mounting base 5 in combination with a lid 4 of the adjusting tank 1 close to the tank wall. This solid matter settling prevention device 3 has a pressure vessel 6 at the top.
, Cylinder 7, and pilot valve 8 by electromagnetic control operation
And a blast mechanism 9 including
To the spout 10 provided on the side of the cylinder 7 of the intermediate pipe 11
And a main pipe 12 extending to the vicinity of the bottom of the tank are connected to each other, and a nozzle 13 that opens toward the center of the bottom of the tank is connected to the lower end of the main pipe 12. Further, the intermediate pipe 11 is provided with an opening valve 14 which is electromagnetically controlled.

The blast mechanism 9 is constructed as shown in FIG. An air intake port 15 for introducing compressed air is provided at one end of the pressure vessel 6, and the air intake port 15 is connected to a compressed air source (not shown) through an air intake pipe 16 that forms a three-pronged pipe.
Further, the pressure vessel 6 is provided at the other end with an opening 17 having a large diameter, and the cylinder 7 is flange-connected. This cylinder 7 is provided with a jet port 10 on its side, a piston 18 is slidably housed inside, and a back pressure chamber 19 is formed on the tip side. The piston 18 has a stopper 20 at the base end side moving end.
And the peripheral surface thereof can close the ejection port. Further, the tip end side of the cylinder 7 is closed by a lid 22 provided with an ejection pipe 21, and this ejection pipe 21 forms a three-pronged pipe, and a pilot valve 8 for electromagnetically controlling operation is connected to the tip of the ejection pipe 21 to form a back pressure chamber. The air inside 19 can be opened to the outside. Furthermore, the branch intake of the intake pipe 16
A branch pipe 25 is connected between the blower pipe 23 and the air supply port 24 of the jet pipe 21, and particularly, the branch inlet 23 and the branch pipe 25
And the opening area of the air supply port 24 to the air intake port 15 at one end of the pressure vessel 6.
The opening area is larger than the opening area.

As shown in FIG. 1, sewage containing fine suspended solid particles from a neutralization tank (not shown) is poured into the adjustment tank 1 equipped with the solid matter settling prevention device 3 having the above-mentioned configuration, as treatment water.
The open valve 14 was opened, and water was introduced into the main pipe 12 through the nozzle 13 at the lower end so that the water surface 26 at the same water level as the adjusting tank 1 was maintained. Next, the solid settling prevention device 3 was operated while adding the polymer coagulant by a mechanical supply means (not shown).

The operation of the solid sedimentation preventing device 3 will be described with reference to FIG. When the pilot valve 8 of the blast mechanism 9 is closed and compressed air is introduced into the intake pipe 16 from a compressed air source such as a compressor (not shown), the compressed air is supplied from the air inlet 15 to the pressure vessel 6
Pumped inward, but at the same time from branch inlet 23 to branch pipeline 25
Then, it is also pressure-fed into the back pressure chamber 19 of the cylinder 7 through the air supply port 24. In this case, since the opening area of each of the branch intake port 23, the branch pipe line 25, and the air supply port 24 is larger than the air intake port 15,
When the compressed gas is fed, the back pressure chamber 19 of the cylinder 7 has a higher pressure than the pressure vessel 6 preferentially, so that the piston 18 slides to the base end side of the cylinder 7 to close the ejection port 10. Maintain position. Next, by electromagnetic control operation, the pilot valve 8
When opened, the compressed air in the back pressure chamber 19 is rapidly released to the outside air, and a large reverse pressure difference is generated between the back pressure chamber 19 and the pressure vessel 6, so that the piston 18 moves rapidly to the cylinder tip side. Then, the spout 10 will be opened. Therefore, the compressed air in the pressure vessel 6 instantly forms a gust from the opened jet outlet 10 and is blown into the main pipe 12 through the intermediate pipe 11,
The water surface 26 in the main pipe 12 is pressurized and pushed down to the lower water surface 26 '. The pressurized and pushed water is discharged from the nozzle 13 at the lower end of the main pipe 12 in the direction of the arrow according to the opening direction. Main pipe 12 by opening operation of this pilot valve 8
Following pressurization of the liquid surface, the release valve 14 attached to the intermediate pipe 11
Is opened by a coordinated electromagnetic control operation, and the inside of the main pipe 12 is communicated with the outside air, water is naturally sucked into the main pipe 12 and the water surface 26 'returns to the initial water surface 26. Further, if the pilot valve 8 is operated in a coordinated manner, the compressed air supplied into the back pressure chamber 19 via the branch passage 25 causes the piston 18 to return to the position where it closes the ejection port 10. To do.

By periodically repeating such discharge and return of water in the main pipe 12, strong and sufficient agitation is performed in the adjusting tank 1 based on the inertial movement, and fine suspended solid particles by the polymer flocculant. The flocculation of solids was carried out, and the sedimentation and accumulation of solids on the bottom of the tank were completely prevented.

The apparatus of the second embodiment of the present invention shown in FIG. 3 is an example in which it is applied to a quadrangular flat-bottomed wastewater pit 27 made of concrete.
A main pipe 28 is fixed to the central part of one side of the sewage pitch 27, and the main pipe 28 has a nozzle 29 that opens horizontally in the lower end part thereof. Intermediate pipe 30 connected to the main pipe 28
Is bent outwardly and is connected to a blast mechanism 32 installed on a pedestal 31 outside the tank, which is the same as the case of the first embodiment of FIG. 1, and an open valve 33 with an intermediate pipe 30 and The configuration of the blast mechanism 32 is also the same. In the case of this type, by discharging the water flow in the horizontal direction by the nozzle 29, a circulating flow in a horizontal plane is generated in an inertial motion, and sedimentation and accumulation of solid matter can be prevented, and the wastewater pit 27 By installing the blast mechanism 32 outside and enlarging the pressure vessel 33, the diameter and length of the main pipe 28 can be enlarged,
In addition, the amount of discharged water can be increased, and it is possible to easily cope with the case where the capacity of the wastewater pit becomes large.

The present invention has a feature that various kinds of nozzles having different opening shapes and opening directions are prepared to cope with the situation of treated wastewater and can be easily dealt with.

[Effect of device]

As is apparent from the above description, according to the present invention, the pipe that communicates with the water in the waste water tank at the lower end is held in the waste water tank,
Water in the pipe is rapidly pushed out by the gust based on the expansion and diffusion caused by the release of air in the pressure vessel of the blast mechanism,
Since it discharges in a predetermined direction and releases the air in the pipe to the outside air to restore the water, a large work, that is, stirring power can be obtained by using a small amount of power, and the settling points of solid particles can be concentrated. The solid particles in a wide range can be prevented from settling by cyclic stirring. In addition, since there are no moving parts in the wastewater tank, there is no risk of damage even if there is sedimentation and accumulation of solid particles. It is possible to obtain a solid material settling prevention device in which the discharge speed or the discharge direction can be changed.

[Brief description of drawings]

FIG. 1 is a sectional view of an adjusting tank provided with a solid matter settling prevention apparatus according to the first embodiment of the present invention, FIG. 2 is a sectional view of a main part of a blast mechanism in the solid matter settling prevention apparatus of FIG. 1, and FIG. FIG. 4 is a sectional view of a wastewater pit provided with the solid substance settling prevention device of the first embodiment of the present invention, and FIG. 4 is a sectional view of a conventional adjusting tank. 1 ... Adjusting tank 3 ... Solid sedimentation prevention device 6 ... Pressure vessel, 7 ... Cylinder 8 ... Pilot valve, 9 ... Blast mechanism 10 ... Discharge port, 11 ... Intermediate pipe 12 ... Main pipe , 13 Nozzle 14 …… Open valve, 27 …… Sewage pit 28 …… Main pipe, 29 …… Nozzle 30 …… Intermediate pipe, 32 …… Blast mechanism 33 …… Open valve, 34 …… Pressure vessel

Claims (1)

[Scope of utility model registration request] 1. A blast mechanism for converting compressed gas accumulated in a pressure vessel into a gust of wind, and a blast mechanism held in a sewage tank, the upper end of which is connected to a jet port of the blast mechanism, and the lower end of which is a lower part of the sewage tank. A pipe that opens in the direction, the pipe has an opening valve near the upper end that opens the inside to the outside air, and by repeating the discharge / return operation of water in the pipe, the solid matter in the waste water tank An apparatus for preventing solids from settling in a sewage tank, which prevents the settling of solids.