JPS6161866B2 - - Google Patents

Description

Detailed Description of the Invention The present invention relates to a flotation separator for solid-liquid separation, and a spiral inclined plate is provided on the outer periphery of a flotation cylinder in a flotation tank to shorten the settling distance of sediment and shorten the settling time. This is to ensure complete separation of sediment and efficient solid-liquid separation.

In general, flotation separation method, which performs solid-liquid separation, is a type of floating separation method in which fine solids and liquid particles suspended in water are floated as they are or attached to air bubbles, and the floating substances are concentrated and separated, and clear water is obtained at the bottom. It is an engineering operation that is widely applied in water treatment fields such as oil-containing wastewater treatment, sewage treatment, and sewage sludge thickening, as well as in the coal industry and textile industry.

A flotation device using this type of flotation separation method is generally equipped with a flotation tank, a floating object scraper, a floating object outlet, a raw water inlet, an air blower, etc.
The raw water to be treated is fed into the flotation tank bottom either as it is or mixed with air, pressurized water, etc., and fine air bubbles are attached to the suspended matter to gradually float it to the water surface. In addition to scraping with a scraper, clear water is collected through separate piping.

In the above-mentioned flotation separation operation, it is ideal to have all floating objects float to the surface and obtain completely clear water, but some of them do not float and settle, resulting in insufficient clear water. This results in a decrease in the recovery rate of floating objects. This is because particles that are floating and particles that are settling are generated simultaneously in the flotation separation tank due to differences in their specific gravity and the presence or absence of air bubbles, and the mixture of these particles causes convection. This is because the sedimentation velocity of the sedimenting particles is relatively low, so that the sedimentation and floating of the particles occur simultaneously at the same location.

Therefore, in order to remove sediment,
A method is adopted in which a sediment scraper is provided at the bottom of a flotation separation tank and is driven to rotate to scrape up sediment and remove it from the tank bottom. However, in this case, not only does it require power, but the structure is also complicated, which is not necessarily satisfactory.

This invention focuses on the above-mentioned points and provides a spiral inclined plate around the outer periphery of the flotation cylinder in the flotation separation tank to enable efficient solid-liquid separation. will be described in detail with reference to drawings showing one embodiment thereof.

In the drawing, 1 is a vertically cylindrical flotation tank with an open top, and 2 is a funnel-shaped tank bottom forming the bottom of the flotation tank 1, which is connected to a sediment outlet 4 through a bottom plug 3. is communicated with. Reference numeral 5 denotes a vertical flotation tube which is coaxially provided in the flotation separation tank 1 and forms a flotation chamber therein. is communicated with an inflow pipe 7 that penetrates the tank wall of the flotation separation tank 1, and suspended water, pressurized water, air, etc. flow into the flotation tube 5 from the inflow pipe 7. Reference numeral 8 designates four spiral-shaped inclined plates that are integrally provided on the outer circumference of the flotation tube 5 and are equally spaced to divide the interior of the flotation separation tank 1 into five stages in the vertical direction. It has an inclination angle and is formed toward the bottom of the flotation separation tank 1, and a spiral settling chamber facing the tank bottom is formed between each inclined plate 8, and is separated from the flotation chamber. It is. Reference numeral 9 denotes a floating object scraper which is installed at the upper end of the flotation separation tank 1 and has a plurality of rubber spatula-shaped scraping plates 10 radially provided on the lower surface;
When the scraper 9 is rotated by the drive of the electric motor 11, floating objects on the upper surface of the flotation separation tank 1 are scraped off. Numeral 12 is a floating material discharge port formed in the upper part of the flotation separation tank 1 to take out the floating material scraped by the scraper 9, and reference numeral 13 is a discharging port 13' at the tip which is opened in the vicinity of the lower surface of each inclined plate 8. There are five clear water take-out pipes, and each take-out pipe 13 is connected to a collecting pipe 14, and further connected to a drain pipe 15.

Next, the operation of the embodiment will be explained.

First, when suspended water, pressurized water, air, etc. are sent from the inflow pipe 7, this becomes a mixture of particle groups with fine bubbles attached and clear water while rising inside the flotation tube 5, and then flows from the flotation port 6. It flows out into the flotation separation tank 1. When the floating objects in the liquid mixture flowing out from the flotation port 6 reach the upper surface of the flotation separation tank 1, they are scraped off by a scraper 9 rotated by an electric motor 11 and discharged from the discharge port 12. On the other hand, among the liquid mixture flowing out from the flotation port 6, sediments 16 that have a relatively large specific gravity or that have insufficient air bubbles settle in the liquid and are deposited on each inclined plate 8. It settles, slides down on the inclined plate 8, is guided to the bottom of the tank, and is deposited on the bottom 2 of the tank. The tank bottom sediment 16' in the tank bottom 2 is collected from the sediment outlet 4 by opening the bottom plug 3.

Further, on the lower surface of each inclined plate 8, the sediment 16 in the vicinity settles onto other inclined plates 8 below, so clear water is separated and collected, and this clear water is collected at each outlet 13. ', and is taken out from the drain pipe 15 via the take-out pipe 13 and the collecting pipe 14.

Therefore, according to the embodiment, by providing four spiral inclined plates 8 at equal intervals around the outer periphery of the flotation cylinder 5 in the flotation tank 1, the sediment 16 is approximately equal to the entire length of the flotation tank 1. The settling distance of each inclined plate 8
Since it can be divided into five stages, it is possible to form a settling distance of 1/5 of the above between each inclined plate 8, and the settling time of the sediment 16 can also be shortened to 1/5.
The sediment 16 can be quickly settled onto each inclined plate 8, and the sediment 16 settled on the inclined plate 8 can be easily deposited at an angle of repose of 60° or more at which the inclined plate 8 allows the sediment 16 to slide down. Since it has an inclination angle, the inclined plate 8
The sediment 16 can be easily taken out without using power or complicating the structure.

In addition, since the flotation chamber in the flotation tube 5 and the settling chamber between each inclined plate 8 are configured to be separated in the flotation separation tank 1, mixing of the floating objects and the sediment 16 is prevented, and both can be effectively Further, since the settling chamber formed between each inclined plate 8 is not affected by the floating water flow, clear water and sediment 16 can be separated very statically. Moreover, since this clear water can be taken out near the bottom surface of the inclined plate 8, which has the highest degree of clarity, completely clear water can be obtained, and the floating matter, sediment 16, and clear water can be extracted. It can separate water efficiently.

Furthermore, in the embodiment, the cylindrical flotation tank 1 is used and its horizontal cross section can be made small, so the sliding angle, that is, the inclination angle, of the inclined plate 8 can be inevitably made large. , the pitch thereof can be made large, and therefore the sediment 16 can be quickly moved to the tank bottom 2.

Note that the inclined plate 8 provided on the outer periphery of the floating tube 5
may be arbitrarily increased or decreased depending on the amount of sediment 16.

As described above, according to the flotation separation device of the present invention, the flotation tube is disposed in the vertical cylindrical flotation tank, and the flotation tube has a spiral shape having an inclination angle such that the sediment can slide down on the outer periphery of the flotation tube. By providing an inclined plate, it is possible to shorten the settling distance of the sediment, shorten the settling time, and increase the overall settling speed.It is possible to reliably prevent mixing of sediment and floating objects, and to improve efficiency. Separation can be achieved and
Complete separation of sediment is possible without complicating the structure or requiring power, and furthermore,
Clear water with a high degree of clarity can be taken out by opening the outlet of the clear water take-out pipe near the lower surface of the inclined plate.

[Brief explanation of the drawing]

The drawing is a partially cutaway sectional view of one embodiment of the flotation separation device of the present invention. 1...Flotation separation tank, 5...Flotation tube, 8...Slanted plate, 13...Cleared water take-out pipe, 13'...Take-out port,
16...Sediment.

Claims (1)

[Scope of Claims] 1. A vertical flotation tube constituting a flotation chamber is arranged in a vertical cylindrical flotation separation tank, and the flotation tube has an angle of inclination to the extent that sediment can slide down the outer periphery of the flotation tube. A flotation separation device characterized in that a spiral inclined plate facing the bottom of the flotation tank is provided. 2. Claim 1, characterized in that an outlet for the clear water outlet pipe is opened near the lower surface of the inclined plate.
The flotation separation device described in section.