JPH0340400Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) This invention uses anaerobic or aerobic fluidized bed sewage treatment equipment, fluidized bed dephosphorization equipment, etc. to collect wastewater to be treated at the bottom of the tank. supply and make it flow upward,
This invention relates to a water sprinkling device for sewage treatment that flows and spreads carrier particles filled in a tank.

(Prior art) Piping for supplying wastewater to be treated into the tank is laid at the bottom of a sewage treatment tank, a nozzle for spouting sewage is installed in this pipe facing downward, and the sewage spouted from the nozzle is directed upward. It is common practice to treat wastewater by fluidizing and expanding carrier particles such as sand or zeolite filled in a treatment tank to form a fluidized bed.

During treatment operation in this way, carrier particles do not enter the nozzle back into the nozzle, but when the operation of pumps such as raw water pumps and circulation pumps that supply wastewater to the piping is stopped, carrier particles enter the nozzle back into the nozzle. It can block the nozzle or get into the piping through the nozzle and accumulate, making it difficult to perform the next startup.

(Problem that the invention aims to solve) For this reason, conventionally a check valve (check valve) was installed in the nozzle.
However, SS contained in wastewater may adhere to the check valve, making it unable to perform its function satisfactorily, and the structure of the nozzle also deteriorates. It becomes complicated and the manufacturing cost becomes very high.

(Means for Solving the Problems) Therefore, the present invention is characterized in that a downwardly directed cylindrical cover having an opening larger than the diameter of the nozzle is provided as an extension of the nozzle that is attached downwardly to the pipe.

(Function) As a result, the lower part of the nozzle is surrounded by a cylindrical cover having an opening larger than the diameter of the nozzle, and the internal capacity of the cover absorbs water hammer etc. when the pump is stopped. The carrier particles form bridges.

(Example) In the illustrated example, 1 is a treatment tank, 2 is a pipe laid at the bottom of the tank, into which waste water is supplied by a pump, and 3 is a nozzle attached downward to the above pipe by welding, screwing, etc. show.

In the embodiment shown in FIGS. 1 and 2, the nozzle 3 is provided with a conical cylindrical cover 4 extending downwardly in diameter.

The cylindrical cover is not limited to a conical shape;
A cylindrical cover 5 with a large diameter may be used as in the embodiment shown in FIG. Furthermore, as shown in FIG.
A conical cylindrical cover 4 as shown in Figures 1 and 2 surrounds the
may be provided and doubled. Note that these covers and tubes are attached to the nozzle by welding or the like. The aperture a of the nozzle 3 is determined depending on the amount of SS contained in the waste water or circulating water and the amount of water to be ejected, but is usually 2 to 30 mm. On the other hand, the diameter of the opening at the large lower end of the conical cover 4 and the diameter b of the opening of the cylindrical cover 5 are set so that b/a is 5 to 10 with respect to the diameter a of the nozzle 3. , approximately 20-200mm, downward length h is
10-200mm is practical.

Note that the apex angle θ of the conical cover 4 is set to 20 to 60° in consideration of the fluidity and angle of repose of the carrier particles to prevent particles from accumulating on the upper surface.

In this way, the cylindrical covers 4 and 5 form a space with a large capacity under the nozzle 3, so that the cylindrical cover prevents carrier particles from entering the nozzle due to water hammer or the like when the pump is stopped. At the same time as the space is absorbed, the carrier particles form a bridge within the cover, preventing them from entering the nozzle.

If a cylinder 6 is provided in the space formed by the cover 4 to further form a small volume space as in the embodiment shown in FIG. 4, the impact when the pump is stopped can be more fully absorbed.

Next, the results of the experiment are shown.

Nozzles 1 and 2 are available for two types of nozzles with diameters of 10 mm and 20 mm.
A cylindrical cover was provided as shown in Figures 3 and 4.

The diameter b of the opening at the lower end of the conical cover in Figures 1 and 2 is 100 mm for a diameter of 10 mm, and 150 mm for a diameter of 20 mm.
The apex angle θ was 30° for the 10 mm aperture and 60° for the 20 mm aperture. Cover height h is 73mm for 10mm diameter, 20mm for diameter 20mm.
The mm version is 36mm.

Further, the diameter b of the opening of the cylindrical cover in Fig. 3 was 90 mm for both the 10 mm and 20 mm diameter cases, and the downward length h was 105 mm for both cases. The diameter of the tube 6 in Fig. 4 is 48 mm for both 10 mm and 20 mm diameters, and the downward length is 48 mm.
It was set to 50mm. The diameter b and apex angle θ of the opening at the lower end of the conical cover are 150 mm for both the aperture of 10 mm and 20 mm.
The angle was set at 30°, and the height h of the cover was set at 107 mm.

These test nozzles and nozzles with a diameter of 10 mm and 20 mm without a cylindrical cover were installed downward into the piping inside a column filled with natural zeolite with a particle size of 0.35 mm, and the amount of water ejected from each nozzle was adjusted to 5 to 30 mm. Visual observation using a fiberscope inserted near the nozzle shows the situation where zeolite enters back when the ejection is stopped and the situation when the ejection is resumed. In some cases, zeolite entered the nozzle backwards, sometimes making it impossible to eject it again, but no zeolite backflow phenomenon occurred in each test nozzle equipped with a cylindrical cover.

Although not shown, the tube 6 shown in FIG. 4 may be provided inside the cylindrical cover 5 shown in FIG. 3.

(Effects of the invention) According to the invention, without incorporating a complicated mechanism such as a check valve, the structure is extremely simple and completely prevents carrier particles from entering the nozzle when the pump is stopped, making it easy to operate the pump. Can be restarted.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a treatment tank equipped with a water sprinkling device according to an embodiment of the present invention, Fig. 2 is an enlarged sectional view of the main part of Fig. 1, and Fig. 3 is a water sprinkling device according to a second embodiment of the present invention. FIG. 4 is an enlarged sectional view of the apparatus similar to FIG. 2, and FIG. 4 is an enlarged sectional view of main parts of another embodiment of the present invention. In the figure, 1 is a processing tank, 2 is a pipe, 3 is a nozzle, and 4 and 5 indicate a cylindrical cover.

Claims (1)

[Scope of Claim for Utility Model Registration] A water sprinkling device for sewage treatment in which piping is laid at the bottom of a sewage treatment tank to supply sewage to be treated into the tank, and a nozzle for spouting sewage is attached downward to this piping. A water sprinkling device for sewage treatment, characterized in that the nozzle is provided with a downwardly directed cylindrical cover extending from the nozzle and having an opening larger than the diameter of the nozzle.