JPH057887A - Aerating and agitating device - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent deposits on the hollow shaft and perform aeration and stirring operation for a long period of time. [Structure] A hollow shaft 2 having a screw 3 at its lower end is directly connected to a hollow motor shaft 11. And this motor shaft 1
A control valve 5 for adjusting the ventilation amount on the anti-load side of No. 1 and a labyrinth mechanism 4 capable of inhaling a small amount of air at the end of the hollow shaft 2 when the control valve 5 is fully closed are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aeration and agitation device for sewage treatment which effectively performs low load operation at the start of aerobic / anaerobic operation and removal of nitrogen in sewage.

[0002]

2. Description of the Related Art As a treatment method for removing organic substances in wastewater, there is a method of agitating wastewater and aerobically treating it by aeration. However, the conventional screw-type aerator with a controllable air flow rate does not have a problem during aerobic operation, that is, during aerobic operation in which air is supplied to the wastewater to decompose and treat organic substances in the wastewater. When ventilation is stopped, the negative pressure inside the hollow shaft sucks up dirty water into the hollow shaft and closes the hollow shaft due to dirty water.Therefore, an oil seal or the like is used to seal between the rotating motor hollow shaft and the fixed side parts. Further, a minute hole is provided, and minute air is made to flow from this minute hole to cope with the problem. For example, as shown in FIG. 3, a minute hole is provided in the connection flange 7A, and the seal 4A is provided on the inner circumference of the motor casing 12A.
To provide.

[0003]

When an oil seal is provided between the hollow shaft of the motor and the stationary member, the negative pressure of the hollow shaft increases the surface pressure of the seal and causes the seal and the contact thereof. Parts are heavily worn and need frequent replacement and repair.

It is an object of the present invention to prevent deposits on the hollow shaft by adopting a labyrinth mechanism, and to carry out a maintenance-free aeration stirring operation which does not require replacement or repair for a long period of time.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above object. A hollow motor shaft is directly connected to a hollow shaft having a screw at its lower end, and the motor shaft has an anti-load. The gist is that a control valve for adjusting the air flow rate is provided on the side, and a labyrinth mechanism capable of inhaling a small amount of air at the end of the hollow shaft when the control valve is fully closed.

[0006]

When the motor 1 rotates the screw 3 at the tip of the shaft through the hollow shaft 2, the waste water is agitated and the negative pressure generated by the propulsive force of the screw in the waste water causes a negative pressure of the motor directly connected to the hollow shaft. Air is sucked from the side opposite to the output shaft side of the hollow shaft and sent out into the water through the hollow shaft. At this time, the air amount is adjusted by opening / closing the control valve 5 provided on the intake side. Even if the control valve 5 is completely closed, the connection flange 7 is provided with the labyrinth 4 having a slight distance from the outer peripheral surface of the hollow shaft. It is filled with sewage and is prevented from entering the hollow shaft, sludge and the like do not adhere and accumulate in the hollow shaft, and smooth driving is possible even when switching to aerobic operation.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on the embodiments shown in FIGS. As shown in FIG. 1, a screw type self-priming aerator A used for treating sewage such as sewage and industrial wastewater has a motor 1 and a hollow motor shaft 1 of the motor 1.
1, a hollow shaft 2 having a required length, a screw 3 provided at the tip of the hollow shaft 2, a labyrinth 4 provided on the opposite side of the motor shaft 11, and a control valve 5 for controlling the air flow rate. It

The hollow shaft 2 has a required length and strength, and when the aeration device A is arranged in an aeration tank or a water channel so as to have a required penetration angle with respect to the sewage water surface, it has a predetermined depth from the water surface. The length is appropriately determined so as to reach, and the screw 3 is fixed to the tip.

A motor shaft 11 of the motor 1 is connected to the base end side of the hollow shaft 2 via a shaft joint 6, and the screw 3 is rotated by the drive of the motor 1 via the hollow shaft 2 to remove waste water. so,
In addition, a negative pressure is generated in the water area at the tip of the screw, and this negative pressure is used to supply air as fine bubbles to the water area at the tip of the screw through the hollow motor shaft 11 and the hollow shaft 2. In this case, although not shown in the drawings, an electric control circuit may be provided in the motor 1 so that the rotation speed of the motor is controlled to adjust the rotation speed of the screw so that aeration and stirring can be adjusted.

The motor shaft 11 is rotatably supported by a casing 12 of the motor 1 via bearings 13, 13, a connecting flange 7 is connected to the casing 12, and a labyrinth is provided on an inner circumference of the casing 12. 4 is provided. Further, the connection flange 7 is provided with a control valve 5, and the control valve 5 is electrically operated to open and close to adjust the ventilation amount, and the shape and the number of stages of the labyrinth 4 are not limited. The control valve 5 is set to have a ventilation amount set during the aerobic operation set last time and can be adjusted according to the load, and is fully closed or close to the fully closed state during the anaerobic operation.

Therefore, in the apparatus constructed as described above, the screw 3 at the tip of the hollow shaft 2 which is driven and rotated by the motor 1 stirs sewage, and the negative pressure generated by the propulsive force of the screw in the sewage causes the hollow to move. Air is sucked from the side opposite to the output shaft of the hollow shaft of the motor that is directly connected to the shaft, and is sent into the water through the hollow shaft. At this time, the air amount is adjusted by opening / 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 and a non-contact type seal is provided with a slight gap from the outer peripheral surface of the hollow shaft, even if the control valve 5 is completely closed, a small amount of air is sucked from the labyrinth 4. , The pressure in the hollow shaft is adjusted, and the infiltration of dirty water into the hollow shaft is prevented. At this time, regardless of whether the valve used is manual, electric, or model, by adjusting the time schedule of opening time and closing time for valves such as solenoid valves that are difficult to adjust the intermediate opening and closing,
Aeration amount can be adjusted.

[0012]

According to the present invention, the amount of aeration can be adjusted without lowering the stirring force without lowering the rotation speed of the hollow shaft, and thus the stirring was separately required to prevent the sludge from settling. No equipment 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 the hollow shaft is filled with air and dirty water does not enter the hollow shaft. Therefore, sludge or the like does not adhere to and accumulate in the hollow shaft, and there is an advantage that it can be driven smoothly even when switching to aerobic operation.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view of an aeration and agitation device of the present invention.

FIG. 2 is an enlarged cross-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]

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

Claims (1)

Claim: What is claimed is: 1. A hollow motor shaft is directly connected to a hollow shaft having a screw at a lower end thereof, and a control valve for adjusting a ventilation amount is provided on an anti-load side of the motor shaft. An aeration and agitation device characterized in that a labyrinth mechanism capable of inhaling a small amount of air is provided at the hollow shaft end when the control valve is fully closed.