JPS58223492A - Aerator - Google Patents

Abstract

PURPOSE:To decrease sticking on the impeller of an aerator by providing a recess to the outer casing in the part corresponding to the impeller of the aerator provided with the impeller by which gas contg. oxygen is injected to liquid to be treated in the flow passage for the liquid to be treated. CONSTITUTION:When a submersible motor 5 is started, the sewage which is liquid to be treated is cleaned up. A recess 14 is formed to an outer casing 7 in the part corresponding to an impeller 4; therefore, even if the solid material such as a wooden piece flowing along the inside of the casing 7 is gnawed in the spacing 15 at the forward ends of the vanes, said material is washed off immediately when it arrives at the recess 14, and the continuous gnawing of the solid material between the casing 7 and the outside circumference of the vanes of the impeller 4 is obviated. The aerator is thus operated stably and continuously without tripping of motor.

Description

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, a flow path for a liquid to be treated is formed between an inner casing and an outer casing, an oxygen-containing gas is injected into the flow path, and a flow path for a liquid to be treated is formed between an inner casing and an outer casing. This invention relates to an aeration device equipped with an impeller for transporting liquid.

Such aeration devices are well known. For example, a typical conventional aeration device B shown in FIG. It is designed to be hung and installed on the bottom of the aeration tank. Since the aeration system @B is used in liquid in this way, the submersible motor 5 is used as the motor of the drive part △, and the impeller 4 is rotationally driven by the submersible motor 5 via the transmission part 3. It has become. The cousing part C consists of an inner casing 6 and an outer casing 7, and a flow path 8 is formed between these two casings 6.7. Both housings 6.7 are enlarged downwards in a clapper-like manner.

The aeration device B configured in this way has a submersible motor 5.
When the impeller 4 is started, the impeller 4 is driven to rotate, and the liquid to be treated is sucked in from the suction port 9 above the flow path 8, and is discharged radially outward from the discharge port 10. An appropriate number of aeration pipes 11 protrude from the flow path 8, and a supply pipe 12
An oxygen-containing gas, such as air, supplied from the annular collecting pipe 13 is injected into the liquid to be treated from the diffuser pipe 11.

By the way, in a conventional aeration device having such a structure, solid matter flows into the sewage every second in the aeration tank, especially in the aeration tank for sewage treatment, so the impeller 4 absorbs these solid matter. Due to adhesion, troubles often occur during operation. In particular, if a solid object such as a piece of wood gets caught in the gap between the impeller 4 and the outer casing 7, the power consumption of the submersible motor 5 will increase, eventually exceeding the motor's rated operating speed, and the submersible motor 5 will start running. L-may also bulge.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an aeration device which can reduce the adhesion of solid matter to the impeller, and in particular can prevent solid matter from being caught between the impeller and the casing.

According to the present invention, one or more depressions are provided in the outer casing at a portion opposite to the impeller disposed in the flow path of one liquid to be treated. Shitakatsu-〇Solid substances such as wood chips can flow out by pouring them into the hollow.

The present invention will be described in detail below with reference to FIGS. 2 and 3. In FIGS. 2 and 3, the same reference numerals as those of the conventional aeration apparatus shown in FIG. 1 are designated by the same reference numerals.

This is the same as the conventional example in that an IJ and an impeller 4 are arranged in a channel 8 through which the liquid to be treated flows, and a suction port 9 is formed at the upper end of the channel 8. According to Mokuha and Ming, Figures 2 and 3
As shown in the figure, one or more indentations 14 are provided in the portion facing the impeller 4, that is, in the radially outward outer cushioning area of the impeller 4. This recess 14 is equal to or exceeds the axial length of the blade tip in the axial direction, and has a width W of 100 to 150 mm, in order to flush out solid matter caught in the impeller tip gap 15. The depth 1-) is formed into a substantially rectangular shape with a depth of 20 mm or less.

With this structure, even if a solid object such as a piece of wood gets stuck in the gap 15 between the outer coussing gear and the outer periphery of the blade of the impeller 4, the solid object will flow away from the blade while the stuck blade reaches the recess 14. This allows the impeller to continue operating stably. It is advantageous to form the angle F between the recess and the inner surface of the outer casing at a substantially right angle for operation as an aeration device. With this configuration, it is possible to prevent the solid matter that has been flushed into the recess from being re-entered into the blade tip gap 15.

The aeration device according to the present invention is configured as described above, and T J3
When the submersible motor 5 is started, the waste water that is the liquid to be treated is purified as described above, but according to the present invention,
Since a gap 14 is formed in the outer casing at the portion facing the impeller, solid objects such as wood chips flowing along the inside of the outer casing can be absorbed by the blade tip gap 15.
Even if solid matter is wedged in, it will be washed away as soon as it reaches the recess 14, and no solid matter will continue to be wedged between the outer casing 7 and the outer periphery of the impeller blades 5-.

Therefore, the aeration system can be stably and continuously operated without causing a t-trip, and the reliability of the aeration system can be significantly improved.

[Brief explanation of the drawing]

Fig. 1 is a side view of a conventional aeration device partially shown in section; Fig. 2 is a side view similar to Fig. 1 showing an embodiment of the present invention;
FIG. 3 is a sectional view taken along line I-1 along a3 in FIG. 4... Impeller 6... Inner casing 7...
・Outer casing 8...Flow path 9...Suction port 14...Indentation Patent applicant Corporation? -1 Ebara Corporation Ebara Infilco Corporation -6-' Figure 1 Figure 3 Figure 2

Claims (1)

[Claims] (i) A flow path for the liquid to be treated is formed between the inner and outer casings, an oxygen-containing gas is injected into the flow path, and the liquid to be treated is injected into the flow path. What is claimed is: 1. An aeration device equipped with a sending impeller, characterized in that an outer casing in a portion facing the impeller is provided with multiple or a plurality of depressions. (ii>1 - The length in the axial direction is equal to or exceeds the axial length of the blade tip, and the width is 1
2. The aeration device according to claim 1, wherein the aeration device has a substantially rectangular shape with a depth of 00 to 150 ml or more. (iii) An aeration device according to claims 1 and 2, characterized in that the edges of the blades have substantially right angles.