JPH0128875Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a rotating rotor type surface aeration device, that is, a mechanical horizontal shaft aerator used in biological treatment equipment such as an oxidation ditch.

In the oxidation ditch, a horizontal aerator is used to supply oxygen to the water to be treated in the ditch and to provide an appropriate flow rate to the water to be treated. What is generally known as a horizontal shaft aerator includes, for example, a section steel 2 provided parallel to and radially around the rotor shaft 1, as shown in FIGS. The blades 3 may be made by attaching strip-shaped plates at intervals, or the blades 11 may be formed by bending a flat plate into a substantially U-shape as shown in FIGS. Adjacent blades 11, 11 arranged radially are connected by bolts and nuts 13 to form a row of impellers, which are arranged at equal intervals in the longitudinal direction of a plurality of rotating shafts 12 to form an impeller row. and so on.

In addition, in FIGS. 1 to 3, 4 is a fitting part with a drive shaft (not shown), 5 is a rib, 6 is a disc, and 7
Reference numeral 8 indicates a reinforcing member interposed between the rotating shaft 1 and the shaped steel 2, 8 indicates a bolt and nut, 14 indicates a stay, and 15 indicates a disc.

Horizontal shaft aerators have rotating blades that plunge into the water to provide aeration and water agitation/flowing effects.As a result, an impact force is generated due to collision with the water surface, but compared to the conventional methods mentioned above, In the case of a rotary motor, a large impact force is generated intermittently, and the load applied to the impeller becomes pulsating, which not only adversely affects the durability of the rotary drive device, but also has insufficient oxygen supply capacity. There were also problems such as a complicated structure.

The purpose of the present invention is to provide a useful horizontal shaft aerator that can accurately solve the above-mentioned problems of conventional devices. In a rotating rotor-type surface aeration device, the impeller is formed by making small pieces of a circular or regular polygonal plate with notches at equal pitches from the outer edge toward the center of the plate, and forming small pieces of the impeller into the notches. This horizontal axis surface stirring aerator is characterized in that it is constructed by sequentially and alternately twisting clockwise and counterclockwise at a predetermined angle.

An embodiment of the present invention will be described based on FIGS. 7 to 9.

First, regarding the manufacturing procedure of the impeller 21, see Section 7.
Disc 2 obtained by cutting a steel plate as shown in Figure a
2, make cuts 23 with equal angle pitch and uniform depth from the outer edge to the center point to form a plurality of fan-shaped pieces 24, 24... radially, and then cut each piece as shown in Fig. 7 b, c. Cut small pieces 24, 24... into 23
A plurality of blades 25, 25 .

The inclination angle θ is an appropriate angle between 0° and less than 90°, but in all the illustrated examples, it is 30°, and this angle θ is relative to the center line of the rotating shaft 26, as is clear from FIG. (each impeller is perpendicular to the axis of rotation 26). Also,
It is efficient to carry out the twisting process using a machine such as a press before welding the cut disk 22 to the rotating shaft 26 made of a steel pipe for piping or the like.

In the embodiment described above, the cut 23 was provided toward the center of the disk 22, but it may be provided away from the center (for example, on a tangent to the rotating shaft 26). The term "center part of the plate" is used in this sense.

FIG. 8 shows a completed product in which the impellers 21 are arranged on a plurality of rotating shafts 26 at equal intervals in the longitudinal direction thereof. In this case, the diameter, wall thickness, and number of blades of each impeller 25, 25... are equal, and their centers coincide with the center line of the rotating shaft 26, and as shown in FIG.
The notches of each impeller are provided so that they overlap when viewed in the line cross-sectional direction, but the blades adjacent in the longitudinal direction of the rotating shaft 26, for example, 25a and 25b, are provided in a plane-symmetrical relationship with each other. That is, they are arranged so that the directions of the twists are opposite to each other.

Note that each impeller may be slightly inclined in the same direction with respect to the rotating shaft 26. Figure 8 middle 2
Reference numerals 7 and 27 are flanges for connection with a drive device (not shown).

The effects of the above embodiment are as follows: (1) The structure of the impeller 21 is extremely simple and can be manufactured using inexpensive materials with significantly less man-hours.

(2) In the illustrated example, each impeller has a uniform number of blades of 36, but it can easily be manufactured with a larger number of blades.

(3) The impeller and rotating shaft can be easily connected by welding, bolting, etc., and the overall structure of the aerator is significantly simpler than conventional ones.

(4) By increasing the number of impeller blades,
The impact force during use is reduced, and even if the impeller rotation speed is increased, the impact force does not change over time (pulsation) and is averaged out, so the rotary drive device is not subject to unreasonable or uneven loads. Without a problem,
Its service life is greatly improved, and its oxygen supply efficiency and water flow performance are also improved.

(5) If adjacent blades are arranged mirror-symmetrically as described above, the water splashed up by the blades can interfere with each other, so the oxygen supply capacity is further improved compared to the case where the blades are not mirror-symmetrical.

Therefore, to give another preferred embodiment of the present invention, if each impeller has an even number of blades (in this case, the number of right-handed and left-handed blades is equal), the impact caused by water This has the effect of canceling out the difference in the direction of the force, thereby reducing the force applied to the rotating shaft. In addition, in the embodiment shown in Fig. 8, when viewed from the - line cross-sectional direction, if adjacent impellers are arranged so as to be slightly evenly shifted so that the notches of each impeller do not overlap, the impellers hitting the water surface at the same time Since the number of sheets is reduced, it becomes possible to further equalize the load on the drive device.

Although the above discussion focused on the equalization and reduction of the load on the aerator and the aeration effect, the present invention can also improve the water circulation effect by the following embodiments.

In other words, in an oxidation ditch, the water flow is in the form of a long and narrow loop, so the flow on the outside is faster than the inside at the corners, which causes the problem that even in straight parts, the flow velocity tends to be uneven across the width of the waterway. However, it is possible to change the inclination angle of the blades between impellers (uniform within the impeller), change the mounting interval of the impellers, or change the diameter of the impeller (disc 2
2) or change the number of blades,
The unevenness of the flow velocity can be corrected by means such as the following. In particular, the above method is very convenient because it can be easily carried out in accordance with the water flow at the site.

As mentioned above, the horizontal axis aerator of the present invention is
It has advantages such as excellent aeration performance and durability, simple structure, and can be manufactured economically.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view of one conventional example, Fig. 2 is a sectional view taken along line A-A in Fig. 1, Fig. 3 is a sectional view taken along line B-B in Fig. 1, and Fig. 4 is a longitudinal sectional view of another conventional example. 5 is a sectional view taken along the line CC, FIG. 6 is a cross-sectional view of the blade in the example shown in FIG. 4, and FIGS. 7 to 9 show an embodiment of the present invention. 7a, b, and c are explanatory diagrams of the manufacturing procedure of the impeller, FIG. 8 is a front view of a completed horizontal shaft aerator, and FIG. 9 is a cross-sectional view taken along the line -2. 21... Impeller, 22... Disc, 23... Notch, 24... Small piece, 25, 25a, 25b... Vane, 26... Rotating shaft, 27... Flange, θ...
Tilt angle.

Claims (1)

[Claims for Utility Model Registration] 1. A rotating rotor-type surface aeration device in which a plurality of impellers each having a plurality of radial blades are arranged on a rotating shaft, wherein the impellers are formed into a circular or regular polygonal plate body. Horizontal shaft surface agitation characterized in that small pieces are formed by making cuts at equal pitches from the outer edge toward the center and are twisted in turn at a predetermined angle alternately clockwise and counterclockwise around the cuts. Aerator. 2. Utility model registration claim 1, wherein each of the impellers is arranged such that adjacent blades in the longitudinal direction of the rotating shaft are symmetrical with respect to a plane perpendicular to the center line of the rotating shaft. Aerator as described in section. 3. The aerator according to claim 1 or 2, wherein each of the impellers is constructed by arranging an even number of the blades. 4. The aerator according to claim 1, 2, or 3, wherein the blades of each of the impellers are arranged with uniform inclination angles within the same impeller. 5. Registration of a utility model in which each of the impellers is arranged at a uniform pitch in the longitudinal direction of the rotating shaft, and the inclination angles of all the blades are uniform for all the impellers. The aerator according to claim 4. 6. The aerator according to claim 4, wherein each of the impellers is arranged such that the inclination angle of each impeller is sequentially changed along the longitudinal direction of the rotating shaft. 7. The aerator according to claim 5, wherein the number of blades and the angle of inclination are uniform between each of the impellers, and the cuts are arranged so that the cuts do not overlap between adjacent impellers. . 8. The aerator according to claim 7, wherein the plates forming each of the impellers have the same diameter and the same thickness.