JPS5951880B2 - Micro bubble generator in flotation separation equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a microbubble generating device used in a device for flotation separation of fine particles in sewage water.

Conventionally, air (No, O2 gas may be used) is dissolved in water to separate the particles in wastewater that contains suspended particles or in wastewater that has been flocculated by adding a coagulant. The air-pressurized dissolved solution was introduced into a separation tank containing waste water, and the above-mentioned procedure was carried out.

Various pressurized flotation devices have been proposed in which microbubbles generated by reducing the pressure of the solution are attached to fine particles in wastewater for flotation separation, but conventional air pressurized dissolution devices of this type are Since a high-pressure pump and a pressurized mixing tank are required, the device becomes complicated and large, and requires a large amount of power. The present invention aims to provide a micro-bubble generator capable of generating extremely micro-bubble without using any of the above-mentioned devices.

' Specific embodiments of the invention will be described below with reference to the accompanying drawings.

Reference numeral 1 in the drawings denotes a flotation box, which is held in the separation water tank 6 with its upper end protruding from the upper surface SL of the scum.

Reference numeral 2 denotes a mixing box with an open end 4 located inside the flotation box 1, and the other end serving as a bubble water pipe 5' communicating with a right eye 16 provided outside the separation water tank via an outer tube 18.

Further, a waste water inlet pipe 3 is provided so as to maintain the opening at a position close to the open end 4 of the mixing box 2. Further, at the upper end of the floating box 1, a scraper 7 is provided which rotates via a drive source 20 provided on a pedestal 19. Furthermore, a scum box 8 is provided on the side wall of the subdivision of this flotation box 1, and the opening end surface is located on the scum level SL surface.
A discharge pipe 8' extending outside the separation tank is connected to the scum box 8. The separation water tank 6 is provided with an overflow weir 21 having a V-shaped notch at its upper edge, and a water collection box 9 that surrounds this overflow weir 21 and communicates with the water collection pipe 10, and a drain cock at the lower end. 11 are installed.

The right eye 16 is formed into a conical shape and communicates with the clear water part of the separation water tank 6 via a conduit 6', and inside this right eye 16 is an air introduction pipe which is one of the components of the bubble generator described later. 13 are provided. Reference numeral 5 denotes a bubble generator, which is provided in an outer cylinder 18 that is connected between the right eye 16 and the bubble water pipe 5'. Built-in guide tube 12
', the plurality of baffle plates 15 provided between the guide cylinder 12' and the outer cylinder 18, the propeller 14, and the open end 13' of the air introduction pipe 13 are positioned near the suction side of the propeller. It consists of:

Reference numeral 22 denotes a resistance device (air flow regulating device) provided in the air introduction pipe 13, and is composed of two regulating valves 22' and 22''. The shape of the open end of the air introduction pipe 13 is not limited to the umbrella shape of the illustrated embodiment, but may be a radial nozzle shape, for example. You can arbitrarily select other formats such as .

The present invention has the following effects due to the above configuration.

When the propeller-type axial flow pump 12 is activated, the clear water in the water tank 6 flows into the spout 16 from the conduit 6', and air is sucked in from the air introduction pipe 13, and the propeller's rotational force and the tip of the baffle plate 15 cause the water to flow into the spout 16. Mixed and sheared to produce fine bubble water, this bubble water is fed from below the mixing box 2 through the bubble water pipe 5'. On the other hand, sewage is sent from the sewage inlet pipe 3 to the mixing box 2 by a feeding device (not shown).

As a result, the substances adsorbed to the air bubbles in the wastewater in the mixing box 2 are:
The scum rises to the surface of the water inside the flotation box 1 along with air bubbles and becomes scum S, where it stagnates. (Floating separation structure) This scum S
is taken out of the water tank 6 through the discharge pipe 8' fed into the scum box 8 by the rotation of the scraper 7. The clear water from which fine particles have been removed passes through the lower opening 17 of the flotation box 1, passes between the water tank 6 and the flotation box 1, and a portion flows into the spout 16 through the conduit 6' as circulating water. Further, clear water (treated water) corresponding to the amount of inflowing sewage passes over the overflow weir 21, is collected in the water collection pipe 10 via the water collection box 9, and is sent to the next process. In the above embodiment, the clear water in the water tank 6 is poured into the spout 16.
However, the present invention is not limited to this, and this pipe is omitted, and clear water from another source is connected to the supply pipe 3.
Needless to say, the waste water may be supplied to the spout 16 through the supply pipe 30, or the conduit 6 and the waste water pipe 3 may be omitted and the waste water may be directly supplied to the spout 16 via the supply pipe 30. .

Moreover, the above-mentioned flotation separation structure is not limited to this, and it goes without saying that it can be easily applied to other different types of flotation and separation mechanisms.

In addition, in the case of sludge with a high concentration of sewage, it can be applied to a sludge concentrator that focuses on SS (suspended solids) and concentrates the SS. The present invention has the following effects due to the above configuration.

(1) It can contain a large amount of air bubbles and can be made extremely fine, thereby making it possible to efficiently remove and separate fine particles from wastewater.

(2) The power required is several tenths of that of conventional pressurized water generators, and operating costs can be significantly reduced. (3) The structure is simple and compact, and equipment costs are low.

[Brief explanation of drawings]

FIG. 1 is an explanatory cross-sectional view showing the main parts of the microbubble generator of the present invention. 1 ... Levitation box, 2 ...Mixing box, 3
...Sewage water pipe, 4 ...Open end, 5' ...Bubble pipe, 5 ...Bubble generator, 6 ...... Separation tank, 6'...
・Conduit, 12... Propeller type axial flow pump, 13
... Air introduction pipe, 14 ... Propeller,
15... Rectifier plate, 18... Outer cylinder.

Claims (1)

[Claims] 1. A drinking spout to which clear water or sewage is supplied is communicated with a mixing box whose opening is located in a flotation box provided in a water tank through an outer cylinder and a bubble water pipe, and A propeller type axial flow pump is provided, the outlet of the air introduction pipe is located on the negative pressure side of the propeller of the propeller type axial flow pump,
A micro bubble generator in a flotation separation device, characterized in that a current plate is provided on the suction side of a propeller.