JP2002273468A - Underwater air mixer - Google Patents

Abstract

(57) [Summary] [Purpose] The flow rate of the discharged water flow is fast, the discharge distance is long, the interference of the air lift with the suction side water channel is small, and the distance of the air riding the water flow is long, so Provided is an underwater air mixer in which the residence time of air is long and a sufficient aeration and stirring effect is obtained. An air flow chamber is provided in which an outer periphery of an axial impeller is surrounded by a bell mouth-shaped draft ring, an umbrella-shaped current plate is provided below the draft ring, and a bottom plate communicating with an air introducing pipe is provided below the rectifying plate.
And a plurality of water discharge grooves 13... 13 in which an opening and a closing portion are separated from each other at an outer peripheral portion between opposing surfaces of the draft ring 4 and the current plate 5, and the opening is guided in a tangential direction. 14 are vertically connected to each other to form air passages 15... 15 that are introduced from the air chamber 10 into the water discharge grooves 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underwater air mixer used for aeration and stirring in a sewage treatment tank or the like.

[0002]

2. Description of the Related Art As shown in FIG. 5, a conventional underwater air mixer has an annular shape extending in the entire circumferential direction of an outer peripheral portion between a bell mouth-shaped lower portion of a draft ring 104 and an opposing surface of an umbrella-shaped rectifying plate 105. The water outlet 107 is opened, and an annular air diffuser 115 is opened in the entire circumferential direction of the outer peripheral portion between the opposing surfaces of the umbrella-shaped current plate 105 and the bottom plate 109. As a result, the water sucked in from the water inlet 106 and the air sent in from the air introduction pipe 108 are respectively formed into an annular water outlet 107 and an air diffuser 115.
Radially from the entire circumference of the water, the flow velocity of the discharge is slow and the discharge distance does not extend, the air wall by the air lift is formed in a ring near the underwater air mixer, and the interference of the suction causes the suction water flow As a result, the residence time of the air in the tank is shortened, and there is a disadvantage that a sufficient aeration and stirring effect cannot be achieved.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a discharge tank having a high flow velocity, a long discharge distance, little interference with a suction-side water flow by an air lift, and a long reach distance of air riding on the water flow. It is an object of the present invention to provide a submersible air mixer which has a long residence time of air in the air and can obtain a sufficient aeration and stirring effect.

[0004]

In the underwater air mixer according to the present invention, an axial impeller is mounted on a lower end of a rotating shaft guided from a vertical shaft submersible motor, and a lower part of a draft ring surrounding an outer periphery of the impeller is mounted. By providing an umbrella-shaped rectifying plate extending outward in a bell-mouth shape and facing the lower surface of the draft ring at a constant interval, a water flow having an upper end opening as a water inlet and a lower outer peripheral portion as a water outlet. An air chamber is formed by facing a bottom plate having an air introduction pipe opened from the center of the lower surface from below the straightening plate to form an air chamber. The opening and the closing part are separated from each other on the outer peripheral part between the openings, and the partition plate is vertically connected so that the opening becomes a plurality of water discharge grooves guided in a tangential direction, and is introduced into each water discharge groove from the air chamber. A diffuser opening to the outside It is preferable that the air diffusion path extends along the bottom of the central part of each water discharge groove.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment will be described below with reference to FIGS.

[0006] 1 is a vertical shaft submersible motor, 2 is a rotating shaft guided from the vertical shaft submersible motor 1, 3 is an axial impeller mounted on the lower end of the rotating shaft 2, 4 is an outer periphery of the impeller 3. A surrounding draft ring, the lower part of which is extended outward in a bell-mouth shape, and provided with an umbrella-shaped rectifying plate 5 facing the lower surface of the draft ring 4 at a constant distance. Thereby, the upper end opening is used as the suction port 6 and the lower peripheral part is used as the water discharge port 7.
Is formed. Reference numeral 8 denotes an air introduction pipe, and 9 denotes a bottom plate having the air introduction pipe 8 opened from the center of the lower surface. The bottom plate 9 is opposed from below the current plate to form an air chamber 10. An opening 11 and a closing portion 12 are separated from each other at an outer peripheral portion between the bell mouth-shaped lower portion of the draft ring 4 and the facing surface of the umbrella-shaped rectifying plate 5.
..A plurality of water discharge grooves 13 in which 11 is guided in the connection direction
13 are installed vertically, and the air chamber 10
13 are opened from the inside into each of the water discharge grooves 13 and 13 and opened to the outer peripheral surface, and these air passages 15 and 15 are located at the center of each of the water discharge grooves 13 and 13. Desirably, it is extended along the bottom of the groove.

[0007]

When the air mixer of the present invention is installed in the aeration tank and driven, water sucked into the draft ring 4 from the suction port 6 by the axial flow impeller 3 along the partition plates 14 The air which is jetted in a tangential direction as a strong water flow from 13 and which is sent into the air chamber 10 through the air introduction pipe 8 diffuses into the water discharge grooves 13.
However, the gas-liquid mixture is distributed in the tank at a distance from the air mixer, and the residence time of the air in the tank becomes longer. In the air mixer of the present invention, the water discharge grooves 13... 13 and the air diffusers 15. Instead of being opened circumferentially, it is opened with the opening 11 and the closing part 12 separated, and the opening area of the outlet is narrowed and narrowed, so that the air wall by the air lift is Since it is not formed in a ring shape, interference with the water flow on the suction side is reduced, and a sufficient aeration and stirring effect can be obtained in combination with the long residence time of the air in the tank. Also,
If the air passages 15... 15 extend along the bottom of the central part of each of the water discharge grooves 13... 13, the air is discharged in a state surrounded by the water flow, so that the aeration function is more effective. Will be performed.

According to the air mixer of the present invention, the speed of the discharge water flow is high, the discharge distance is long, the interference of the air lift with the water flow on the suction side is small, and the distance of the air riding on the water flow is long, and Residence time at
There is an advantage that a sufficient aeration and stirring effect can be obtained.

[Brief description of the drawings]

FIG. 1 is a vertical sectional side view showing a main part of a configuration of an underwater air mixer of the present invention.

FIG. 2 is a plan view of a current plate in the underwater air mixer of the present invention.

FIG. 3 is a development view of an outer peripheral edge of a draft ring, a flow straightening plate, and a bottom plate in the underwater air mixer of the present invention, showing a case where an air diffusion path is extended along a groove bottom of a water discharge groove.

FIG. 4 is a development view of an outer peripheral edge of a draft ring, a flow straightening plate, and a bottom plate in the underwater air mixer of the present invention, showing a case where an air diffusion path is extended along a bottom of a central part of a water discharge groove.

FIG. 5 is an explanatory diagram showing a gas-liquid ejection path in the underwater air mixer of the present invention.

FIG. 6 is an explanatory diagram showing a gas-liquid ejection path in a conventional underwater air mixer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vertical shaft underwater motor 2 Rotating shaft 3 Impeller 4 Draft ring 5 Rectifier plate 6 Water intake port 7 Water discharge port 8 Air introduction pipe 9 Bottom plate 10 Air chamber 11 Opening 12 Closing part 13 Water discharging groove 14 Partition plate 15 Air passage

Claims (2)

[Claims] 1. An axial impeller is mounted on a lower end of a rotating shaft guided from a vertical shaft underwater motor, and a lower portion of a draft ring surrounding an outer periphery of the impeller is outwardly extended in a bell mouth shape. ,
By providing an umbrella-shaped rectifying plate facing the lower surface of the draft ring at a constant interval, a water flow generating mechanism having an upper end opening as a water inlet and a lower outer peripheral portion as a water outlet is provided, and air is generated from the center of the lower surface. An air chamber is formed by facing the bottom plate having the introduction pipe opened from below the straightening plate, and an opening and a closing portion are provided on an outer peripheral portion between the opposed surfaces of the bell mouth-shaped lower portion of the draft ring and the umbrella-shaped straightening plate. And the partition plate is vertically connected so that the opening becomes a plurality of water discharge grooves guided in the tangential direction, and the air diffuser is introduced into each water discharge groove from the air chamber and opened to the outer peripheral surface. An underwater air mixer characterized by the establishment of 2. The air diffusion path, which is introduced from the air chamber into each of the water discharge grooves and opened to the outer peripheral surface, extends along the bottom of the central groove of each of the water discharge grooves. Item 7. An underwater air mixer according to item 1.