JPH0630242Y2 - ▲ Ro ▼ Passing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a type of overpass device that supports an overlayer filled with a granular support material by a support layer filled with a granular support material, and more particularly, an overflow device by upflow. The present invention relates to an excess device capable of preventing a localized floating phenomenon of a support layer during cleaning.

[Prior Art] As a typical example of an excess device for various water treatments, as shown in FIG. 3, a water collecting chamber 2 is formed at the bottom of the tank 1, and gravel is provided above the water collecting chamber 2. Support layer 3 filled with a granular support material such as
Is provided, and the overlayer 4 filled with sand, anthracite, and other granular materials is supported on the support layer 3.

Then, the raw water to be passed is supplied to the overlayer 4 in a downward flow, and after the suspended matter is captured in the overlayer 4, the overflow through the support layer 3 is collected in the water collection chamber 2 and flows out from the overdrain 5. To do.

When the suspended matter in the raw water is accumulated in the overlayer 4 while continuing such an excess, and the overresistance increases to a predetermined value, the overlayer 4 needs to be washed. To wash the overlayer 4, when the obtained overwater or other washing water is pressed into the water collection chamber 2, the washing water passes upward through the support layer 3 and is dispersed to form a uniform upward flow. The layer 4 is loosened to make the particulate material float, and the suspended particulate matter is carried over to the cleaning drainage trough 6 provided at the upper portion and discharged to the outside of the tank 1.

By the way, in such cleaning by the upward flow, the upward flow velocity is limited, and if the speed is too high, a so-called landing phenomenon that causes the support layer 3 to float occurs, and the granular material of the supported overlayer 4 becomes the support layer 3. It gets into the inside of the body, and after that, it causes a serious disorder in hyperfunction, such as unevenness in the body. On the other hand, if the upward flow velocity is too low, the overlayer 4 cannot be loosened as a matter of course, resulting in poor cleaning. Therefore, the upward flow velocity at the time of cleaning has a certain appropriate range, although it depends on the structure of the water collection chamber 2.

[Problems to be solved by the device]

However, in the conventional passing device, the horizontal cross-sectional area of the support layer 3 is the same as the horizontal cross-sectional area of the overlayer 4, and even if the upward flow velocity during cleaning is within the proper range, the support materials in the support layer 3 are The porosity of the difference between the vicinity of the tank wall and the vicinity of the center of the tank causes a difference in the upward flow velocity at the time of cleaning, and the upward flow along the tank wall is blocked by the tank wall, and the support layer 3 in the portion along the tank wall is It often caused local floating phenomena.

An object of the present invention is to provide an over-apparatus having a simple structure which prevents a localized landing phenomenon of a support layer and does not impair over-function in such an up-flow washing of an over-layer. is there.

[Means for Solving the Problems]

The present invention provides a support layer filled with a granular support material in a tank,
A tank wall portion in the support layer, in which an overlayer filled with a granular material is supported on the support layer, and washing of the overlayer is performed in an upward flow by introducing wash water from below. In the above apparatus, the outer peripheral portion of the support layer is bulged into the tank wall so that the upward flow is uniformly dispersed.

[Action]

In the overpass device of the present invention, as in the conventional device, the downflow or the upflow is performed, but during the upflow cleaning of the overlayer, the floating of the support layer supporting the overlayer is prevented. , The local floating phenomenon of the supporting layer does not occur.

That is, most of the washing water that flows upward at a predetermined flow rate during overlayer cleaning is dispersed by the support layer, and the upward flow along the tank wall also causes the porosity between the support materials as shown by the second arrow. Is uniformly formed, and enters the bulging portion of the support layer and is sufficiently dispersed, so that the flow velocity distribution in the bath at the time of cleaning is made uniform, and the bath wall of the support layer at an upward flow velocity within a predetermined range. No local landing phenomenon was observed in the vicinity, and there is no hindrance to overfunctioning after washing.

〔Example〕

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a filtration device according to the present invention, in which a water collecting chamber 2 is formed at the bottom of the tank 1 and an upper part of the water collecting chamber 2. Is provided with a support layer 13 filled with a granular support material such as gravel, and an overlayer 4 filled with a granular material such as sand or anthracite is supported on the support layer 13. In addition, the water collection chamber 2 is communicated with a permeate drain 5, and a cleaning drainage trough 6 for discharging the cleaning drainage accompanied by suspended matter is provided in the upper part of the tank 1 after cleaning the overlayer 4. .

Further, the horizontal cross-sectional area of the support layer 13 is not the same as the horizontal cross-sectional area of the overlayer 4 as in the prior art, and the tank wall prevents the upward flow along the tank wall in the support layer 13 during cleaning. A groove is formed on the inner circumference of the tank wall so that the support layer 13 is bulged into the groove so that the horizontal cross-sectional area of the support layer 13 is wider than that of the overlayer 4. As a result, the porosity of the tank wall is kept constant. The bulging portion is preferably 5 to 20 times the particle diameter of the support material, preferably about 50 to 300 mm.

Therefore, as shown by the arrow in FIG. 2, the washing water flowing upward through the water collecting chamber 2 during the washing of the overlayer 4 is sufficiently dispersed by the flow along the tank wall entering the bulging portion as well. The floating phenomenon of the supporting layer 13 does not occur, and the upper layer 4 is effectively washed with a uniform upward flow in the entire tank.

[Effect of device]

As described above, the present invention provides the support layer filled with the granular support material in the tank, supports the overlayer filled with the granular material on the support layer, and cleans the overlayer from below with the washing water. In order to make the upward flow even in the tank wall portion in the support layer, the outer periphery of the support layer is bulged into the tank wall. As a result, the conventional difference in the flow velocity along the tank wall that causes floating of the support layer is eliminated, the upward flow velocity distribution in the entire tank becomes uniform, and the local floating phenomenon near the tank wall of the support layer is eliminated. Prevented,
Does not interfere with overfunction.

[Brief description of drawings]

FIG. 1 is a vertical side view showing an embodiment of the present invention, and FIG. 2 is an explanatory view of an upward flow state near a tank wall in the present invention,
FIG. 3 is a vertical cross-sectional side view of a conventional example of the excess device. 1 ... Tank, 2 ... Water collection chamber, 3, 13 ... Support layer, 4 ... Overlayer,
5 ... Superfluid, 6 ... Washing drainage trough.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location 8925-4D B01D 29/08 Z

Claims (1)

[Scope of utility model registration request] 1. A support layer filled with a granular support material is provided in a tank, and an overlayer filled with the granular material is supported on the support layer,
In a passing apparatus in which washing water is introduced from below to perform washing in an upward flow, a supporting layer is provided so that the upward flow is evenly distributed even in the tank wall portion in the supporting layer. An excess device in which the outer peripheral portion is bulged into the layer wall.