JPS6318411Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in coarse screens used in sewage treatment systems.

Conventionally, the basic flow of sewage treatment facilities that utilize the purification effect of living organisms is that sewage flows into a settling tank, passes through a rough screen section, and reaches a flow rate adjustment tank.
From this tank, the water is pumped through a meter and a fine screen to a biological treatment tank, where the organic matter contained in the wastewater is decomposed by the action of microorganisms and purified, and then disinfected and PH It is discharged after processing such as adjustment.

Therefore, in order to always maintain a constant purification function, it is necessary to supply an appropriate amount of nutrient source to the microorganisms in the biological treatment tank.

However, as for the rough screen in the above-mentioned flow, a bar screen having a circulating rake is used, but the rake in this screen is provided on both sides of each screen bar. The comb blades that come into sliding contact are arranged in rows, and therefore, in addition to the intended purpose such as toilet paper and vinyl pieces, the fecal pellets that serve as a nutritional source for microorganisms are also removed, making it difficult to preserve microorganisms. It had some drawbacks.

The reason for this is that the pitch of the rake's comb blades is thin, so all the coarse floating matter is scraped up.
If the pitch of the screen bar was too rough, it would no longer function as a screen, and solving this problem was an issue.

The present invention was developed in view of the above-mentioned current situation, and each rake is provided with comb blades for one set that can run along both sides of one screen bar, with an interval of at least every other screen bar, and the position of the next stage rake and comb blades. The purpose of this invention is to not only eliminate the above-mentioned drawbacks by using a coarse screen characterized by staggered arrangement of the screens, but also to produce many accompanying effects such as being inexpensive and requiring less power.

To explain in detail based on the embodiment shown in the figure, 1 is a bar screen body made up of a large number of screen bars 1a arranged diagonally in parallel at appropriate intervals, and 2 is a sprocket arranged vertically on both sides of the lower part of the screen body 1. 2 endless chains stretched by 3 and 4 and driven in circulation by an appropriate drive device (not shown);
Rakes 5a, 5b, and 5c are arranged at equal intervals to connect the endless chains 2, 2, and each rake has a set of two combs that can slide on both sides of the screen bar 1a during circulation. The blade 6 is attached to the screen bar 1a.
The rakes 5a, 5b, and 5c are arranged with the comb blades 6 of the rakes 5a, 5b, and 5c sequentially shifted from those of the next stage, so that all the rakes 1a can be raked evenly.

However, during operation, since the comb blades 6 are arranged at intervals, the lateral pitch is large;
Therefore, if only one set of comb blades 6 is used, floating objects (mainly toilet paper and vinyl pieces) get entangled with the screen bar 1a that the comb blades engage with.
The fecal pellets spill laterally and remain in the stream.

The screen bar 1a that has not been raked by one raking rake is successively raked by the succeeding rakes of the next and subsequent stages.

It should be noted that the comb blades 6 can be arranged in the same manner as long as the pitch in the horizontal direction is equal to or more than every other screen bar 1a.

In the coarse bar screen according to the present invention constructed as described above, the comb blades of each rake are provided at intervals, so if only one set of comb blades is used, only the toilet paper/vinyl pieces can be scratched. The fecal pellets are spilled and remain in the sewage flow, and are eventually broken down into small pieces by dissolution, etc., pass through the screen, and are further broken down by pumping from the flow rate adjustment tank and sent to the subsequent biological treatment tank. Therefore, it is possible to sufficiently supply a nutrient source to the microorganisms in the processing tank. In addition, the number of comb blades is smaller than that of conventional rakes, resulting in a reduction in cost, as well as reduction in power costs due to weight reduction and reduction in raking resistance, and other great effects.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a side view of the overall arrangement, FIG. 2 is an enlarged view of FIG. 1 in the direction of arrows, and FIG. 3 is an enlarged view of FIG.
It is an arrow sectional view. In the figure, 1 is a bar screen body, 1a is a screen bar, 2 is an endless chain, 5a, 5b, 5c are scraping rakes, and 6 is a comb blade.

Claims (1)

[Scope of utility model registration request] In a bar screen having a plurality of scraping rakes that are driven in circulation, each rake is provided with comb blades for one set that can run along both sides of one screen bar, at intervals of at least every other screen bar, and A coarse bar screen characterized by having rakes arranged with different comb blade positions.