JPH04277089A - Aeration stirring device in waste water treatment - Google Patents

Abstract

PURPOSE:To effectively carry out a low load operation and removal of nitrogen from waste water at the start of an aerobic or anaerobic operation. CONSTITUTION:A hollow shaft 2 having a screw 3 at its lower end is connected directly to a hollow motor shaft 11. The motor shaft 11 is provided oppositely from its loaded side with a control valve 5 for adjusting the amount of the air ventilated and a small hole 4 for permitting air to be sucked therethrough into the hollow shaft when the control valve is closed completely. As above- mentioned, since the air is sucked through the small hole into the hollow shaft, even when the control valve is completely closed during an anaerobic operation, the hollow shaft is filled with air and, consequently, the entry of waste water into the hollow shaft is avoided. Therefore, there is no adhesion or deposition of sludge or the like within the hollow shaft and a smooth driving can be effected even at the time of switching to an aerobic operation.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aeration agitation device for wastewater treatment, which performs low-load operation at the start of aerobic/anaerobic service and effectively removes nitrogen from wastewater.

0002

BACKGROUND OF THE INVENTION As a treatment method for removing organic substances from wastewater, there is a method in which wastewater is stirred and treated aerobically by aeration. However, conventional screw-type self-priming aeration equipment operates exclusively aerobically, that is, it supplies air into wastewater to decompose and treat organic substances in the wastewater. Furthermore, when the load on the aeration device is low, or when nitrogen in sewage is treated, so-called denitrification treatment, it is necessary to reduce the amount of aeration from the aeration device. For this reason, the aeration equipment is operated intermittently or completely stopped, and a stirrer is installed separately from the aeration equipment to prevent sedimentation and accumulation of sludge at this time.

0003

[Problem to be Solved by the Invention] Therefore, when a self-priming aeration device is operated intermittently or completely stopped, when the aeration device is stopped, a screw is provided at the tip and a screw is provided to perform ventilation for aeration. Since the shaft is a hollow shaft, sewage and sludge may enter or adhere to the hollow shaft, narrowing or blocking the aeration passage, reducing the amount of ventilation, and reducing the aeration efficiency during full operation of the aeration system. This is causing a decline. Furthermore, in addition to the aeration device, a stirrer is required.

[0004] The present invention is a single self-priming aeration device that provides aerobic and
The purpose is to perform both anaerobic and anaerobic operation, prevent deposits from accreting on the hollow shaft that performs aeration, and perform efficient aeration and stirring operation over a long period of time.

[0005]

[Means for Solving the Problems] The present invention has been made to achieve the above-mentioned object, and includes directly connecting a hollow shaft having a screw at the lower end to a hollow motor shaft, and also The gist is that a control valve for adjusting the amount of ventilation is provided on the side, and a microhole is provided in the hollow shaft to allow air to be taken in when the control valve is fully closed.

[0006]

[Operation] In a screw-type self-priming aeration device, the amount of ventilation must be controlled within the rotating screw or hollow shaft. A seal is created between the rotating screw or hollow shaft and the parts that adjust the airflow, but it has traditionally been difficult to achieve a complete seal due to vibrations of the hollow shaft during operation, and the structure is complex. . However, the motor shaft that is directly connected to the hollow shaft with a screw at the tip is also hollow, and a control valve is provided on the opposite side of the load, and this control valve is provided with a small hole that draws air into the hollow shaft even when the shaft is closed. Therefore, even when performing anaerobic operation by reducing the ventilation amount of the aeration device, ventilation can be carried out inside the hollow shaft, although it is smaller than the micropores. Therefore, suction of sewage into the hollow shaft due to negative pressure can be prevented, and clogging of the inside of the hollow shaft with sludge can be prevented. Furthermore, the structure is extremely simple compared to the conventional one, and since no mechanism is provided inside the hollow shaft, cleaning can be easily performed and maintenance work efficiency can be improved. Even when the valve is fully closed, the micropores achieve their function by allowing a small amount of air to flow through the closed area. Therefore, the target may be a valve body, a valve box, a motor shaft, a hollow shaft, etc., and it may be anywhere.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained below based on the illustrated embodiments. As shown in FIG. 1, a screw type self-priming aeration device A used in the treatment of sewage such as sewage and industrial wastewater includes a motor 1 and a hollow shaft of a required length that is directly connected to a hollow motor shaft 11 of the motor 1. A shaft 2, a screw 3 provided at the tip of the hollow shaft 2, and a microhole 4 provided on the anti-load side of the motor shaft 11.
, and a control valve 5 for controlling the amount of ventilation.

The hollow shaft 2 has a required length and strength, and when the aeration device A is placed in an aeration tank or a waterway at a required angle of entry to the sewage water surface, the hollow shaft 2 has a predetermined depth from the water surface. The length is determined appropriately so that it reaches , and the screw 3 is fixed to the tip.

A motor shaft 11 of a motor 1 is connected to the base end side of the hollow shaft 2 via a shaft coupling 6, and a screw 3 is rotated via the hollow shaft 2 by driving the motor 1, and the screw 3 is rotated through the hollow shaft 2, and the screw 3 is rotated through the hollow shaft 2. in,
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 into the water area at the screw tip through the hollow motor shaft 11 and the hollow shaft 2. In this case, although not shown, the motor 1 may be provided with an electric control circuit so that the rotation speed of the screw can be adjusted by controlling the rotation speed of the motor, thereby adjusting the aeration and stirring.

The motor shaft 11 is rotatably supported by a casing 12 of the motor 1 via bearings 13, 13, and the ventilation pipe 7 is connected to the casing 12 by a seal ring 8.
A small hole 4 is provided in a part of the outer periphery of the ventilation pipe 7. This micro hole 4 has a metal fitting 40 in the ventilation pipe 7.
are screwed together. Furthermore, the ventilation pipe 7 is provided with a control valve 5, and the control valve 5 is operated as an electric opening/closing type to open and close to adjust the amount of ventilation. The control valve 5 is set to the previously set ventilation amount during aerobic operation, can be adjusted according to the load, and is fully closed or close to fully closed during anaerobic operation.

Therefore, in the device configured as described above, when the screw 3 at the tip of the rotating hollow shaft 2 driven by the motor 1 is submerged in water, the negative pressure generated by the propulsive force of the screw is used to directly connect the hollow shaft. Air is sucked in from the side opposite to the output shaft of the hollow shaft of the motor and sent out into the water, and the amount of air is adjusted by opening and closing a control valve 5, such as an electric ball valve, provided on the intake side. At this time, the type of valve used does not matter whether it is manual or electric, and the amount of aeration can be adjusted by adjusting the time schedule of the opening time and closing time for valves such as solenoid valves that are difficult to adjust in the middle. Note that when the valve is fully closed, a minute amount of air is supplied into the water through the minute hole 4. In addition, in butterfly valves and the like, a small hole is bored in the center of the valve body so that a small amount of air can be supplied into the water even when the valve is fully closed.

0012

[Effects of the Invention] According to the present invention, the amount of aeration can be adjusted without lowering the rotation speed of the hollow shaft and without reducing the stirring power, so a stirring device, which was conventionally required separately to prevent sludge settling, can be adjusted. becomes unnecessary. In addition, even when the control valve is fully closed during anaerobic operation, air is sucked into the hollow shaft through the micro holes, so the hollow shaft is filled with air and no dirty water enters into the hollow shaft. It has the advantage that sludge, etc. does not adhere and accumulate inside, and it can be driven smoothly even when switching to aerobic operation.

[Brief explanation of the drawing]

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

FIG. 2 is an enlarged sectional view of main parts.

[Explanation of symbols]

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

Claims (1)

[Claims] [Claim 1] A hollow shaft with a screw provided at the lower end is directly connected to a hollow motor shaft, and a control valve for adjusting the ventilation amount is provided on the anti-load side of the motor shaft, and when the control valve is fully closed. 1. An aeration agitation device for wastewater treatment, characterized in that a hollow shaft is provided with micropores that allow air to be taken in.