JPH1110188A - Screw type aerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smoothly perform an aeration process even if an aeration tank has a great depth, when air is discharged from an opening formed at an end of a hollow shaft, by forming the hollow shaft to a specific length and providing a shut-off valve in an air pipe interconnecting a blower and the hollow shaft. SOLUTION: In the screw type aerator, a screw 4 is provided on the outer periphery of an end of a hollow shaft 3 and air can be discharged into the water from an opening formed at the end of the shaft 3. In this case, the length of the shaft 3 is made 3 m or more and a motor 1 to rotationally drive the shaft 3 through a transmission mechanism 7 and a blower 2 to introduce air into the shaft 3 are set on the surface of the water and a shut-off valve 9 is provided in an air pipe 8 interconnecting the blower 2 and the shaft 3. Thus even in an aeration tank 10 having a depth of 3 m or more, flow speeds of foul water at the bottom of the tank 10 and the extent of flow of the foul water caused by a screw 4 can be maintained, while the foul water can be smoothly aerated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw type aerator in which a screw is provided on the outer periphery of the tip of a hollow shaft which is rotationally driven by an electric motor and air is discharged into water from an opening formed at the tip of the hollow shaft. In particular, the present invention relates to a screw-type aerator installed in a deep aeration tank having a water depth of 3 m or more used in sewage and sewage treatment plants.

[0002]

2. Description of the Related Art Conventionally, in order to perform aeration while agitating sewage, a screw is provided on the outer periphery of the tip of a hollow shaft that is driven to rotate by an electric motor, and air is discharged into water from an opening formed at the tip of the hollow shaft. Screw type aerators are widely used (for example, see Japanese Patent Publication No. 56-21452). This screw aerator generates a negative pressure in the water area at the tip of the screw by rotating and driving the screw through a hollow shaft, sucks air through the hollow shaft and discharges it into the water. The aeration of the sewage is performed by forming fine bubbles by the stirring action of the screw and diffusing them into water.

[0003]

However, in recent years, due to the demand for increased wastewater treatment and effective use of land, the water depth has been reduced to 3 m.
The above deep aeration tanks are being used.
When the above-mentioned conventional screw-type aerator is directly applied to such a deep aeration tank having a depth of 3 m or more, as shown in FIG. The spread of the flow is small,
Due to the influence of water pressure and buoyancy, the air released into the water is not diffused, and it is not possible to perform aeration treatment of sewage smoothly.If the length of the hollow shaft is increased, depending on the water depth, Had the problem that air was not released into the water. In this type of aeration tank,
The process is performed while alternately performing aerobic and anaerobic operations.However, during anaerobic operation, sewage infiltrates into the upper part of the hollow shaft, causing sludge and hair to adhere and causing a failure of the aerator. There was a problem of becoming.

[0004] The present invention solves the above-mentioned problems of the conventional screw type aerator, and even in an aeration tank having a large depth of water, the air can be surely diffused into the water without being affected by water pressure and buoyancy to contaminate the wastewater. It is an object of the present invention to provide a screw-type aerator capable of smoothly performing the aeration treatment of (1) and preventing sludge and hair from adhering to the inside of the hollow shaft.

[0005]

In order to achieve the above object, a screw type aerator according to the present invention is provided with a screw at the outer periphery of the distal end of a hollow shaft driven and rotated by an electric motor, and an opening formed at the distal end of the hollow shaft. In the screw-type aerator designed to discharge air into the water, a hollow shaft is formed with a length of 3 m or more, and an electric motor that drives the hollow shaft to rotate on water and a blower that introduces air into the hollow shaft are installed. A shutoff valve is provided in an air supply pipe connecting the blower and the hollow shaft.

In this screw type aerator, a hollow shaft provided with a screw on the outer periphery of the tip is formed to have a length of 3 m or more, and air is introduced into the hollow shaft by a blower, so that the water depth is 3 m or more. Even in a deep aeration tank, air can be reliably diffused into water without being affected by water pressure and buoyancy, and aeration treatment of sewage can be performed smoothly. Further, during anaerobic operation, by shutting off a shutoff valve provided in an air supply pipe connecting the blower and the hollow shaft, it is possible to prevent sewage from invading above the inside of the hollow shaft, and to prevent sludge from entering the inside of the hollow shaft. And hair are not attached.

In this case, the hollow shaft can be divided into parts, the periphery of the connecting portion of the hollow shaft can be fixed with an adhesive, and the outside can be covered with a cover.

[0008] By dividing the hollow shaft, the handleability during transportation and the like is improved. Further, by fixing the periphery of the connection portion of the hollow shaft with an adhesive and covering the outside with a cover, it is possible to prevent sludge, hair, and the like from adhering to the connection portion and growing.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the screw type aerator according to the present invention will be described below with reference to the drawings.

1 to 3 show one embodiment of a screw type aerator according to the present invention. This screw type aerator is rotatably supported by a bearing 6 and provided with a screw 4 on the outer periphery of a distal end of a hollow shaft 3 driven to rotate by an electric motor 1, and into water through an opening formed at the distal end of the hollow shaft 3. The hollow shaft 3 is formed to have a length of 3 m or more, and the air is introduced into the electric motor 1 and the hollow shaft 3 that rotationally drive the hollow shaft 3 on water through a transmission mechanism 7. The blower 2 is installed, and a shutoff valve 9 is provided in an air supply pipe 8 that connects the blower 2 and the hollow shaft 3.

As shown in FIG. 2, the hollow shaft 3 is divided into a plurality of parts (in this embodiment, divided into two parts) in accordance with the length thereof. I do. Connection 5 of this hollow shaft 3
The coupling 51 provided at the lower end of the upper hollow shaft 3A and the coupling 52 provided at the upper end of the lower hollow shaft 3B are fitted together and fixedly connected by bolts / nuts 53. In this case, the coupling 5
The fitting surfaces 51a and 52b of the first and the second 52 are formed in a tapered shape, whereby the lower hollow shaft 3B is firmly fixed to the upper hollow shaft 3A by being tightened by bolts and nuts 53, and the hollow shaft 3 is rotated. The vibration at the time of driving is suppressed. Also, bolts and nuts 5
The outer periphery of the couplings 51 and 52 including the third member 3 is solidified with an adhesive 54 having water resistance and appropriate elasticity, and the outside thereof is further improved with an elasticity made of a sheet member made of a synthetic resin or a metal such as stainless steel. Cover 55, and the upper and lower ends of the cover 55 are inserted and locked into locking portions 51b and 52b formed in the couplings 51 and 52, whereby sludge and hair adhere to the connecting portion 5, Try to prevent it from growing.

In this screw type aerator, a hollow shaft 3 provided with a screw 4 on the outer periphery of the tip is formed to have a length of 3 m or more, and air is introduced into the hollow shaft 3 by a blower 3. Even with a deep aeration tank having a water depth of 3 m or more, while ensuring the flow rate of the wastewater at the bottom of the aeration tank 10 and the spread of the flow of the wastewater by the screw 4,
Without being affected by the water pressure and the buoyancy, the air can be surely diffused into fine bubbles in the water by the stirring action of the screw 4 to smoothly perform the aeration treatment of the sewage. Further, by fixing the periphery of the connecting portion 5 of the hollow shaft 3 with an adhesive 54 and covering the outside thereof with a cover 55, when the hollow shaft 3 is driven to rotate, sludge and hair adhere to the connecting portion 5 and grow. Can be prevented.

Further, when performing anaerobic operation, as shown in FIG. 3, while introducing air into the hollow shaft 3 by the blower 3, an air supply pipe 8 connecting the blower 2 and the hollow shaft 3 is provided.
By shutting off the blower 2 after closing the shutoff valve 9 provided in the hollow shaft 3, the water level H of the sewage invading the inside of the hollow shaft 3 can be lowered.
It is possible to prevent sludge, hair and the like from adhering to the inside.

[0014]

According to the screw type aerator of the present invention,
A hollow shaft with a screw provided on the outer periphery of the tip is formed to have a length of 3 m or more, and air is introduced into the hollow shaft by a blower. The air is reliably diffused into the water and the aeration treatment of the sewage can be smoothly performed without being affected by the water. Also, during anaerobic operation, by shutting off a shutoff valve provided in an air supply pipe connecting the blower and the hollow shaft, it is possible to prevent sewage from invading above the inside of the hollow shaft. A stable aeration treatment can be performed for a long period of time without adhesion of hair or hair.

Further, the hollow shaft is divided into parts, the periphery of the connection part of the hollow shaft is fixed with an adhesive, and the outside is covered with a cover, so that the handling property at the time of transportation and the like is improved, and the connection part is formed. Sludge and hair can be prevented from attaching and growing.

[Brief description of the drawings]

FIG. 1 is a front view showing one embodiment of a screw type aerator according to the present invention.

FIG. 2 is an enlarged sectional view showing a connection portion of the hollow shaft.

FIG. 3 is an explanatory diagram during the anaerobic operation.

FIG. 4 is a front view showing a conventional screw type aerator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electric motor 2 Blower 3 Hollow shaft 4 Screw 5 Connection part 51 Coupling 52 Coupling 53 Bolt and nut 54 Adhesive 55 Cover 8 Air supply pipe 9 Air shutoff valve 10 Aeration tank

Claims (2)

[Claims] 1. A screw type aerator in which a screw is provided on the outer periphery of the tip of a hollow shaft that is rotationally driven by an electric motor and air is discharged into water from an opening formed at the tip of the hollow shaft. In addition to the above-described length, an electric motor that rotationally drives the hollow shaft on water and a blower that introduces air into the hollow shaft are installed, and a shutoff valve is provided in an air pipe that connects the blower and the hollow shaft. Screw type aerator. 2. The screw type aerator according to claim 1, wherein the hollow shaft is divided, and the periphery of the connecting portion of the hollow shaft is fixed with an adhesive, and the outside is covered with a cover.