JP2936020B2 - Aeration stirring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aeration / agitating apparatus in sewage treatment for effectively performing low load operation and removing nitrogen from sewage at the start of aerobic / anaerobic operation.

[0002]

2. Description of the Related Art As a treatment method for removing organic substances in sewage, there is a method in which sewage is stirred and aerobically treated by aeration. However, the conventional screw-type aerator capable of controlling the ventilation rate has no problem during aerobic operation, that is, during aerobic operation in which air is supplied to sewage to decompose and treat organic substances in sewage, but during anaerobic operation. When the ventilation is stopped, the negative pressure in the hollow shaft sucks up sewage into the hollow shaft and closes the hollow shaft due to the sewage. Further, micro holes are provided, and micro air flows through the micro holes to cope with the problem. For example, as shown in FIG. 3, a minute hole is provided in the connection flange 7A, and a seal 4A is provided on the inner periphery of the motor casing 12A.
Is provided.

[0003]

When an oil seal is provided between the motor hollow shaft and the stationary member as described above, the negative pressure of the hollow shaft increases the surface pressure of the seal, and the seal and the seal come into contact with each other. Parts are severely worn and need to be replaced and repaired frequently.

[0004] It is an object of the present invention to prevent a substance adhering to a hollow shaft by employing a labyrinth mechanism, and to perform a long-time aeration and agitation operation with no maintenance and no replacement or repair.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above-mentioned object, and has a structure in which a hollow shaft provided with a screw at a lower end is directly connected to a hollow motor shaft, and the motor shaft has a counter load. The gist is that a control valve for adjusting the ventilation amount is provided on the side and a labyrinth mechanism capable of inhaling minute air is provided at the end of the hollow shaft when the control valve is fully closed.

[0006]

When the screw 3 at the tip of the shaft is rotated by the motor 1 via the hollow shaft 2, the waste water is agitated, and the negative pressure generated by the thrust of the screw in the waste water causes the negative pressure of the motor directly connected to the hollow shaft. Air is sucked from the output shaft side of the hollow shaft and sent out into the water through the hollow shaft. At this time, the amount of air is adjusted by opening and closing the control valve 5 provided on the intake side. Even if the control valve 5 is completely closed, since the connection flange 7 has the labyrinth 4 having a minute interval with the outer peripheral surface of the hollow shaft, minute air is sucked from the labyrinth 4 and air is always in the hollow shaft. The hollow shaft is filled with the wastewater and is prevented from entering the hollow shaft. Sludge and the like do not adhere to and accumulate in the hollow shaft, and can be driven smoothly even when switching to the aerobic operation.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the embodiments shown in FIGS. As shown in FIG. 1, a screw-type self-priming aeration apparatus A used for treating sewage such as sewage and industrial wastewater includes a motor 1 and a hollow motor shaft 1 of the motor 1.
A hollow shaft 2 having a required length directly connected to the motor shaft 1, a screw 3 provided at the tip of the hollow shaft 2, a labyrinth 4 provided on the non-load side of the motor shaft 11, and a control valve 5 for controlling the air flow. You.

The hollow shaft 2 has a required length and strength. When the aeration device A is disposed in an aeration tank or a water channel or the like so as to have a required intrusion angle with respect to the sewage water surface, the hollow shaft 2 has a predetermined depth from the water surface. , And its length is appropriately determined, and the screw 3 is fixed to the tip.

A motor shaft 11 of the motor 1 is connected to the base end of the hollow shaft 2 via a shaft coupling 6. so,
In addition, a negative pressure is generated in the screw tip water area, and the negative pressure is used to supply air as fine bubbles into the screw tip water area via the hollow motor shaft 11 and the hollow shaft 2. In this case, although not shown, an electric control circuit may be provided in the motor 1 to control the number of rotations of the motor to adjust the number of rotations of the screw, thereby making it possible to adjust aeration and stirring.

The motor shaft 11 is rotatably supported by a casing 12 of the motor 1 through bearings 13, 13. A connecting flange 7 is connected to the casing 12, and a labyrinth is provided on the inner periphery of the casing 12. 4 is provided. Further, a control valve 5 is provided on the connection flange 7, and the control valve 5 is opened and closed as an electric open / close type to adjust the amount of air flow. The shape and the number of stages of the labyrinth 4 are not limited. The control valve 5 is set to have the air flow rate at the time of the aerobic operation set last time, can be adjusted according to the load, and is fully closed or almost fully closed during the anaerobic operation.

Therefore, in the apparatus constructed as described above, the screw 3 at the tip of the hollow shaft 2 driven and rotated by the motor 1 stirs the sewage and generates a negative pressure due to the negative pressure generated by the driving force of the screw in the sewage. The air is sucked from the output shaft side of the hollow shaft of the motor directly connected to the shaft, and is sent out into the water through the hollow shaft. At this time, the amount of air is adjusted by opening and closing the control valve 5 such as an electric ball valve provided on the intake side. Since the labyrinth 4 is provided on the connection flange 7 to provide a non-contact type seal at a minute interval from the outer peripheral surface of the hollow shaft, even if the control valve 5 is completely closed, the minute air is sucked from the labyrinth 4. The pressure in the hollow shaft is adjusted to prevent infiltration of sewage into the hollow shaft. At this time, regardless of the type of valve used, manual or electric, and the type of valve that is difficult to adjust intermediate opening and closing such as solenoid valve, by adjusting the time schedule of open time and close time,
The aeration amount can be adjusted.

[0012]

According to the present invention, the amount of aeration can be adjusted without lowering the rotation speed of the hollow shaft and without lowering the stirring power. Therefore, the stirring required separately to prevent the sedimentation of sludge in the past. No equipment is required. Also, during anaerobic operation, even if the control valve is fully closed, a small amount of air is sucked into the hollow shaft from the labyrinth, so that the hollow shaft is filled with air and sewage does not enter the hollow shaft, Therefore, there is an advantage that sludge or the like does not adhere and accumulate in the hollow shaft, and that the driving can be performed smoothly even when switching to the aerobic operation.

[Brief description of the drawings]

FIG. 1 is a partially broken front view of the aeration and stirring device of the present invention.

FIG. 2 is an enlarged sectional view of a main part.

FIG. 3 is an explanatory diagram of a main part structure that the inventors have conventionally considered.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Motor 11 Motor shaft 2 Hollow shaft 3 Screw 4 Labyrinth 5 Control valve

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) C02F 3/20 C02F 3/30 C02F 7/00

Claims (1)

(57) [Claims] 1. A control valve for directly connecting a hollow shaft provided with a screw at a lower end thereof to a hollow motor shaft, and adjusting a flow rate to a non-load side of the motor shaft; Aeration stirrer characterized by having a labyrinth mechanism at the end of the hollow shaft capable of inhaling minute air.