JPH0337688Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field The present invention relates to an aeration screen for sewage treatment.

BACKGROUND TECHNOLOGY A conventional aeration screen for sewage treatment will be briefly explained. The pneumatic screen was implemented by the applicant about 20 years ago.

A sewage treatment screen is installed at the inlet of a sewage treatment equipment.In a typical screen, foreign substances caught in the vertical screen are removed manually or mechanically using a Reiki-like tool. It was removed by scraping it up from the bottom to the top.
However, these operations are not very suitable for small-scale sewage treatment equipment because manual operations are cumbersome and unclean, and mechanical operations are complicated and expensive.

On the other hand, an aeration-type screen has no moving parts and uses the force of the aeration to remove foreign substances caught in the screen's eyes, so it has a simple structure and is trouble-free.
It has the advantage of easy maintenance management.

The structure and operation of the above-mentioned conventional aeration screen will be briefly explained. FIG. 8 is a side view of a perforated screen in which coarse and fine screens are arranged in series. The only difference between the two is the size of the screen width, everything else is the same.
The rough screen, that is, the left part of FIG. 8 will be explained.

The vertical members of the screen are strip-shaped, and the vertical members are arranged parallel to the water flow and at a constant pitch.
P ₁ and its frame is placed at right angles to the water flow. Also, these vertical members 1
is inclined at a certain angle α when viewed from the side, and a diffuser pipe 2 is provided below the inclined lower surface.

Next, the operation will be explained with reference to the left part of FIG. Among the foreign substances in the inflowing wastewater, relatively large particles _K1 are first caught on the surface of the coarse screen 1. However, these impurities are pushed up by the upward force _A1 of the air bubbles Ab that eject from the air diffuser 2 below the screen, are removed from the screen surface, fall, and are deposited on the bottom of the screen tank. . Since the inside of the tank is kept in an aerobic state by ventilation, accumulated foreign matter will not rot and emit a bad odor. When the screen tank is filled with the removed contaminants, a vacuum truck or the like is used to pull out the contaminants and carry them out of the tank for disposal. In this way, relatively large foreign matter K ₁
The wastewater W ₁ from which K 2 has been removed enters the next fine screen tank, where relatively small impurities K ₂ are removed by the same action, and the wastewater W ₂ flows out to the next treatment step.

Problems to be solved by the invention As mentioned above, conventionally, two screen tanks, one coarse and one fine, and two screen devices for each are used.
They needed a group.

Means for Solving the Problems The purpose of the present invention is to integrate a coarse screen and a fine screen to form a set of equipment and a tank, thereby reducing construction costs.

The gist of the present invention is to integrate the vertical members of the coarse screen by setting the vertical members of the fine screen back a certain distance between each of the vertical members of the coarse screen. This allows both functions of the fine screen to be performed at the same time.

The basic structure of the present invention will be explained. Please refer to FIGS. 1 and 2. Rough vertical members 5a, 5b,
Between each pitch P ₃ (equal pitch) of 5c..., at 1/2 pitch (P ₄ ), vertical members 6a, 6b,
6c, . . . are interposed one by one. The front line F ₂ where these fine vertical members are arranged is more than the front line F ₁ where the coarse vertical members are arranged,
It retreats by a certain distance S. This retreat distance S
is normally preferably larger than the interval T ₂ between the fine longitudinal members and the coarse longitudinal members.

Action: Recess distance S between the coarse vertical members and fine vertical members mentioned above
The reason why is larger than the interval T ₂ of the coarse vertical members will be explained. Please refer to Figure 3. The size of foreign objects K ₅ and K ₆ that pass through the width of the coarse screen, that is, the interval T ₁ between the coarse vertical members, and get caught on the front surface (F ₂ line) of the fine screen, that is, the fine vertical members are: It is larger than the width of the fine screen, that is, the spacing T ₂ of the fine vertical members. That is, _K5 to _K6 > _T2 . In the same equation, when the difference between K ₆ and T ₂ is relatively small, K ₆ falls between the front line F ₂ of the fine longitudinal member and the front line of the coarse longitudinal member, but if K If ₅ is relatively larger than T ₂ , it will extend beyond the front line F ₁ of the roughening stringer. In this case K ₅ may interfere with the action of the coarse screen. Therefore, in order to avoid this, the retreat distance S should be made as large as possible than _T2 . However, this is not an absolute condition and varies depending on the nature of the target wastewater.

The above-mentioned contaminants in sewage were assumed to be three-dimensional objects with the same size, but in the case of elongated shapes (normal contaminants), S may be about the same as T ₂ . That is, the front line of the vertical member for coarse grain F ₁ and the front line of the vertical member for fine grain.
The distance S from F ₂ is determined by taking into consideration the nature of the wastewater to be handled.

Generally, the width of a coarse screen is said to be about 50 mm, and the width of a fine screen is said to be about 20 mm.
Therefore, the pitches of each vertical member in this structure are P ₃ and P ₄
are determined by their width and the thicknesses D ₁ and D ₂ of the longitudinal members.

That is, P ₃ = D ₁ × 1/2 + T ₂ + D ₂ + T ₂ + D ₁ × 1/2 P ₄ = D ₁ × 1/2 + T ₂ + D ₂ × 1/2 For example, the width (interval) of a fine screen T ₂ = If 20 mm is used as a reference and D ₁ = 14 mm and D ₂ = 8 mm, then T ₁ = 48 mm, P ₃ = 62 mm, and P ₄ = 31 mm.

Furthermore, if the width (interval) of the coarse screen is T ₁ = 50 mm, then T ₂ = 21 mm, P ₃ = 64 mm, and P ₄ = 32 mm.

Example 1st example. The basic type described above can be applied as is.

Second example. This example is based on the basic type of the present invention, that is, the first
As a modification of the structure of the embodiment, as shown in FIG. 4, the rough vertical members in FIG. 2 are modified. In other words, the rear half of each of the rough vertical members 7a, 7b, _7c , .
are on the front line _F2 of the vertical members 8a, 8b, 8c, . . .

The differences in operation and effect between this embodiment and the first embodiment are as follows. First, FIG. 5 shows the state of screening of solid substances in the first example. The foreign matter K ₇ that has flowed in (the size is 50 mm>K ₇ >20 mm) passes between the rough vertical members 5b and 5c.
And one end of the solid K ₇ K ₇ E ₁ is the vertical member 6 for fine grains.
b, but the other end K ₇ E ₂ goes along the side (flat) of the coarse vertical member 5b and enters between the fine vertical members 5b, moves further and lies down to meet the fine vertical member 5b. One end of the _contaminant that was in contact with _it may come off and pass through the fine screen. That is, there is a risk that the longitudinal dimension may pass through the fine screen.

On the other hand, in the screen of this embodiment, as shown in FIG. 6, one end K ₉ E ₂ of the solid material K ₉ on the side of the coarse vertical member 7b hits the stepped edge E of the vertical member, The other end K ₉ E ₁ hits the front face of the fine vertical member, and eventually both ends come into contact and its passage is blocked.

The calculation formula for each pitch P ₅ and P ₆ in this example is: P ₆ = D ₃ × 1/2 + T ₄ + D ₄ × 1/2 P ₅ = D ₃ × 1/2 + T 4 + D _{4 + T 4 +} D _{3 ×} 1/2 In the above formula, T ₄ = 20mm is the standard, D ₃ = 18mm,
If D ₄ = 8 mm and R = 5 mm, P ₆ = 33 mm, P ₅ = 66 mm, and T ₃ = 58 mm.

Furthermore, if T ₃ = 50 mm is used as a reference, P ₅ = 58 mm, P ₆ = 29 mm, and T ₄ = 16 mm.

Third example. In this embodiment, re-fine vertical members are added to the first embodiment. Please refer to FIG. Between the coarse vertical members 9a, 9b, 9c, . . . , fine vertical members 10a, 10b, 10 are provided.
c, . . . are interposed, and re-fine vertical members 11a, 11b, 11c, . . . are further interposed between them. The front line F ₃ of these re-fine vertical members is set back by a required distance S ₂ from the front line F ₂ of the fine vertical members.

The effect of this structure is that in addition to the coarse and fine screening in the previous example, it also functions as fine screening, and a single screen can remove solids of around 10 mm. It can be done.

The formula for calculating each pitch in this example is as follows. The thickness of the longitudinal members for fine refining and their spacing, the pitch is D ₇ , T ₇ , P ₉ , P ₁₀ , the thickness of the longitudinal members for fine refining and their spacing, the pitch is D ₆ , T ₆ , D ₈ , Furthermore, the thickness of the vertical members for coarse graining, their spacing, and pitch are determined by D ₅ , T ₅ ,
If P ₇ , P ₁₀ = D ₅ × 1/2 + T ₇ + D ₇ × 1/2 P ₉ = D ₇ × 1/2 + T ₇ + D ₆ × 1/2 P ₈ = D ₅ × 1/2 + T ₆ + D ₆ ×1/2 P ₇ =D ₅ ×1/2+T ₅ +D ₅ ×1/2.

Here, T ₇ = 10mm is the standard, T ₆ > 20mm, T ₅
>50mm, and D ₇ = 8mm, D ₆ = 12mm, D ₅ = 16mm, then T ₆ = 28mm, T ₅ = 68mm, P ₁₀ = 22mm, P ₉ = 20mm,
P ₈ = 42mm, P ₇ = 84mm Also, if T ₆ = 20mm, T ₇ = 6mm, T ₅ = 52mm, P 8 = 34mm P ₉ = 16mm, _{P 10 =} 18mm, P ₇ = 68mm Furthermore, T Based on ₅ = 50mm, T ₆ = 19mm, T ₇ = 5.5mm, P ₈ = 33mm, P ₉ = 15.5
mm, P ₁₀ = 17.5 mm, P ₇ = 66 mm.

Effects As described above, according to the aperture screen according to the present invention, a single screen can perform multiple screening functions at once by adding coarse mesh, fine mesh, or fine mesh to those, and the structure is simplified. This greatly contributes to reducing equipment costs and simplifying maintenance management.

[Brief explanation of the drawing]

FIG. 1 is a side view of the basic type (first embodiment) of the present invention, FIG. 2 is a cross-sectional view taken along line "A"--A in the same figure, and FIG. 3 is an explanatory diagram of the effect of screening in the same structure. Fig. 4 is a cross-sectional view of the screen of the structure of the second embodiment of the present invention, Fig. 5 is an explanatory diagram of the case where a longitudinal solid object passes through the structure of the first embodiment, and Fig. 6 is a longitudinal cross-sectional view of the structure of the second embodiment of the present invention. Figure 7 is a cross-sectional view of the screen having the structure of the third embodiment, Figure 8 is a side cross-sectional view of a conventional aeration screen, and Figure 9 is a diagram of the same as above. FIG. 10 is a cross-sectional view of "F-"F in the same figure. Explanation of main symbols, 5a, 5b, 5c, ...;
7a, 7b, 7c, ...; 9a, 9b, 9c, ...
...Rough-grained vertical members, 6a, 6b, 6c, ...; 8a,
8b, 8c, ...; 10a, 10b, 10c, ...
...Fine vertical members, 11a, 11b, 11c, ...Re-fine vertical members, F ₁ ...Front line of coarse vertical members,
F ₂ ...Front line of vertical material for finer material, F ₃ ...Front line of vertical material for re-fine material, S, S ₁ , S ₂ ... Retraction distance of front line of various vertical materials.

Claims (1)

[Claims for Utility Model Registration] 1. Fine vertical members 6a, 6b, 6c... are interposed between coarse vertical members 5a, 5b, 5c..., and the front side of the fine vertical members 5a, 5b, 5c... Line F ₂ is a certain distance S from the front line F ₁ of the vertical member for coarse graining mentioned above.
A vent-type screen for sewage treatment, characterized in that it is installed in a receding position. 2 Further fine vertical members 11a, 11b, 11 are provided between the coarse vertical members 9a, 9b, 9c... and the fine vertical members 10a, 10b, 10c...
_{c , .} The vent-type screen for sewage treatment as described in item 1. 3. In the cut plane of the coarse vertical member, both sides of the rear half follow the front line F ₂ of the fine vertical member and have a step R with a wall thickness D ₃ as stated in claim 1 of the utility model registration claim. A vent-type screen for sewage treatment.