JPH03267190A - Pressure floatation apparatus - Google Patents

Abstract

PURPOSE:To improve the floating-up separation efficiency in a floatation vessel by supplying the water to be treated flowing out of a mixing chamber to the water surface of the floatation vessel without agitation of water in the floatation vessel with the water to be treated. CONSTITUTION:In a pressure floatation apparatus, the water to be treated supplied from a supply opening 3 is mixed with pressurized water supplied from a supply opening 4 in a mixing chamber 2. The mixed water to be treated in which the floating matter contained in the water in the form of bubbles is supplied uniformly on the water surface of the floatation vessel 1 from scattering opening 11 of a distribution pipe 10 through a rotary column 9. The slanting angle of a guide plate 12 is selected to supply the water on the water surface according to the character of the water to be treated. The floated matter which is floated and separated on the water surface in the floatation vessel 1 is removed by a scraping means 29.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention supplies pressurized water to be treated to a flotation tank and uses air bubbles to float solid particles, which are suspended substances contained in the water to be treated. The present invention relates to a pressurized flotation separation device that separates solid and liquid.

(Prior technology) Pressure flotation separates air by pressurizing the water to be treated, which is contained in the form of suspended solids or particles, and constantly dissolving the pressurized water to be treated. When the water is returned to pressure, the air dissolved in the water to be treated is released as fine bubbles, and these fine bubbles are attached to the particles in the water to be treated, causing them to float, thereby separating solids and liquids. It is about.

Separation devices according to the prior art are known from Japanese Patent Publication No. 56-23668 and Japanese Patent Publication No. 58-2:1153. All of these devices supply raw water to be treated into a liquid in a flotation tank and perform flotation separation in the liquid.

In the conventional technology, water to be treated and pressurized water are supplied into the liquid in the flotation tank for flotation separation, so the water to be treated causes a convection phenomenon in the flotation tank, and as a result, the water to be treated and pressurized water are supplied into the flotation tank. The water to be treated is stirred by convection.

However, when the water to be treated is stirred in the flotation tank, the particles float once they reach near the bottom of the flotation tank, and it takes a long time for all the particles to float. Therefore, the only way to increase the separation efficiency of the water to be treated is to increase the size of the flotation tank.

For this reason, in the prior art, when the amount of water to be separated increases, it is necessary to provide a large flotation tank, which causes problems such as poor investment efficiency of equipment.

(Problems to be Solved by the Invention) The present invention provides a process for supplying treated water onto the liquid surface of a flotation tank to prevent the occurrence of convection due to the to-be-treated water in the flotation tank, thereby significantly improving treatment performance. An object of the present invention is to provide a pressure flotation separation device.

(Means for Solving the Problems) The means for achieving the above object includes a flotation tank, a mixing chamber in which treated raw water and pressurized water are supplied from the bottom, and a treated water in which treated raw water and pressurized water are mixed in the mixing chamber. A water supply means for supplying water with suspended substances contained in the water attached to air bubbles from the upper part of the mixing chamber to the liquid surface of the flotation tank, and adjusting the supply angle to an arbitrary angle; A treated water collection port provided at the bottom of the flotation tank, a floating object removal means for removing floating objects floated and separated on the liquid surface of the flotation tank, and maintaining the water surface height of the flotation tank at a predetermined height. water surface height holding means.

(Function) The treated raw water and pressurized water supplied to the bottom of the mixing chamber are mixed in the mixing chamber, and since the mixing chamber is at atmospheric pressure, they gradually flow upward while precipitating air bubbles inside the mixing chamber. The precipitated air bubbles adhere to particles, which are suspended substances contained in the water to be treated, and are supplied from the upper part of the mixing chamber onto the liquid surface of the flotation tank. Therefore, particles whose specific gravity has become smaller due to the adhesion of air bubbles float on the liquid surface of the flotation tank, and the floated and separated particles are scraped up and removed by the skim rake.

Further, since the water to be treated flowing out of the mixing chamber is supplied to the liquid surface of the flotation tank, no convection phenomenon occurs in the flotation tank due to the supplied water to be treated.

For this reason, the treatment residence time in the flotation tank is shortened, making it possible to significantly increase the throughput per unit volume of the flotation tank.

(Example) Fig. 1 is a vertical sectional view of the entire assembled device of the present invention, Fig. 2
The figure is also a plan view. In these figures, the flotation tank l has a circular planar shape, and a cylindrical mixing chamber 2 is provided in the center of the tank, and a treated raw water supply port 3 and a pressurized water supply port 4 are provided at the bottom of the mixing chamber 2. It is set up. The treated raw water supply port 3 is connected to a treated raw water tank 5, and the pressurized water supply port 4 is connected to a pressurized tank 6.

The treated raw water tank 5 is connected to the treated raw water supply port 3 via a pump, a flow rate adjustment valve, and a flow meter, so that the treated raw water stored in the treated raw water tank 5 and the treated raw water stored in the pressurized tank 6 can be Pressurized water is supplied to the bottom of the mixing chamber 2, respectively. In addition, treated water taken out from a treated water tank 7 provided outside the flotation tank 1 is stored in the pressurized tank 6 together with air after being pressurized by a pressurized water pump. In addition, the pressurized water supply port 4 and the pressurized tank 6
A pressure reducing valve, flow meter, and flow regulating valve are installed in the passageway between the pipe and the pipe. Furthermore, a chemical tank 8 storing a chemical such as a coagulant is connected to the passage via a pump.

At the upper end of the mixing chamber 3, a cup-shaped rotary cylinder 9 with its bottom facing upward is rotatably provided. A distribution dispersion pipe 10 extending in the radial direction is fixed to the rotary cylinder 9.

Further, the distribution and dispersion pipe 10 is formed with a dispersion port 11 that opens along the pipe, and the water to be treated (mixed raw water and treated water) flowing out from the mixing chamber 3 is passed through the distribution and dispersion pipe 10. Then, the liquid is sprayed onto the liquid surface of the flotation tank 1 from above.

3 and 4 show details of the distribution and dispersion pipe and the guide plate, and in these figures, the distribution and dispersion pipe IO
A dispersion guide plate 12 is provided at the dispersion port 11 so that the installation angle can be adjusted. This dispersion guide plate 12 is rotatably attached to mounting plates 13 provided on both sides of the base end or brackets 14 formed on both sides of the lower surface of the distributing and dispersing pipe 10 through a center shaft 15. It is fixed with a fixing bolt 17 via a long hole 16. Therefore, the inclination angle of the dispersion guide plate 12 can be adjusted within the range of the elongated hole 16. However, this adjustment mechanism may have other structures.

The dispersion guide plate 12 configured in this manner allows the supply angle to be selected according to the properties of the water to be treated, so that the tip is positioned slightly away from the liquid surface of the flotation tank (Fig. 3A), and the liquid The water to be treated can be supplied to the flotation tank by selecting either a position in contact with the surface (Fig. 3 B) or a position submerged in the liquid but very shallow from the liquid surface (Fig. 3 C). .

Referring again to FIGS. 1 and 2, a rotatable drive shaft 19 is fixed to the rotary cylinder 9, which projects vertically from a frame 18 provided on the upper surface of the flotation tank L.
Rotation drive device provided on the frame 18! 20 drive gears 21 and a driven gear 22 provided at the upper end of the drive shaft 19 are interlocked by a chain 23.

Note that 24 is a seal structure installed between the mixing chamber 2 and the rotary cylinder 9, and 25 is a bear link installed between the frame 18 and the drive shaft 19.

Further, the distribution and dispersion pipe 10 is provided with a skim rake 27 via a mounting leg 28 on the back side of the dispersion port 11 for scraping up the floating matter 26 floated and separated on the liquid surface of the flotation tank. The skim rake 27 is provided at an angle with respect to the distribution and dispersion pipe 10.
At the same time, when rotating in the flotation tank, the floating objects 26 floating on the liquid surface are pushed out toward the peripheral wall of the flotation tank.

On the other hand, a discharge rake 29 is provided at the distal end of the distribution and dispersion pipe 10 toward the circumferential wall of the flotation tank 1. I try to discharge it from 30 onwards. Note that the flotation tank l is provided with a flotation object outlet 31 corresponding to the flotation object discharge port 30. 32 is a discharge pipe connected to the floating object outlet 31.

In addition, a sediment rake 34 is provided at the bottom of the flotation tank 1 for collecting sediment into the sediment removal port 33. The sediment lake 34 is connected to the mixing chamber 2.
They are provided in a radial direction around the center, are connected to the rotary tube 9, and rotate as the rotary tube 9 rotates. In addition, a water collection pipe 36 is provided on the lower surface of the partition plate 35 provided near the bottom of the flotation tank 1, and a gauge pipe 37 connected to the water collection pipe 36 is raised and opened in the treated water tank 7, whereby the flotation This gauge tube 37 measures the water surface height of tank 1.
I am trying to match the start-up dimensions of . 38 is a drain pipe provided in the treated water tank 7, and 39 is a drain pipe connected to the sediment removal port 33, which is opened and closed by a valve and is normally closed.

In the pressurized flotation separation apparatus configured as described above, treated water stored in the treated water tank 7 is pressurized together with air by the pressurized water pump and supplied to the pressurized tank 6. Therefore, the pressurized tank 6 stores treated water in which a large amount of air is dissolved. The treated water stored in the pressurized tank 6 is supplied to the bottom of the mixing chamber 2 together with the medicine sent out from the medicine tank 8 via the medicine supply pump. In addition, the treated raw water stored in the treated raw water tank 5 is supplied to the bottom of the mixing chamber 2 from the treated raw water supply port 3 by a pump, and is mixed with the pressurized water supplied from the pressurized water supply port 4 (to be mixed with the water to be treated). ) rises in the mixing chamber 2.

Since the mixing chamber 2 is maintained at atmospheric pressure, the air dissolved in the high-pressure treated water supplied from the pressurized water supply port 4 is precipitated as minute bubbles and contained in the water to be treated. Attach to particles.

The water to be treated, which has reached the upper end of the mixing chamber 2, is uniformly supplied to the liquid surface in the flotation tank 1 from the dispersion port 11 of the distribution and dispersion pipe 10 through the rotary tube 9 together with air bubbles or attached particles. The installation angle of the guide plate 12 provided below the spraying port 11 can be adjusted, and the inclination angle of the guide plate 12 can be arbitrarily selected depending on the properties of the water to be treated to supply the water onto the liquid surface.

Particles contained in the water to be treated that is supplied to the liquid surface of the flotation tank l are quickly floated and separated, collected on the peripheral wall of the flotation tank l by the skim rake 27 rotating together with the distribution spray pipe 10, and discharged. Floating object discharge port 30 by rake 29
be gathered to.

Further, precipitates having a higher specific gravity than water settle at the bottom of the flotation tank 1, and are scraped into the precipitate removal port 33 by the raking action of the precipitate rake 34. Therefore, only water (treated water) that does not contain floating matter and sediment flows into the water collection pipe 36 and is supplied to the treated water tank 7 via the gauge pipe 37. A portion of the treated water supplied to the treated water tank 7 is either circulated and supplied to the flotation tank l together with air by the pressurizing action of the pressurized water pump as described above, or the remaining treated water is discharged from the drain pipe 38. Ru.

In the above embodiment, the floating objects are collected on the peripheral wall of the flotation tank by a skim rake and taken out from the floating object discharge port provided on the outside of the flotation tank. represents an example.

FIG. 5 shows a device for suctioning and discharging floating materials using a pump, in which a suction cup 40 is provided in the distribution pipe 10, and a second skim rake 41 is tilted toward the suction cup 40 so as to scrape up the floating materials. It is provided. or,
The suction cup 40 is connected to a pump (not shown) and suctions and discharges floating objects. Therefore, in this case, it goes without saying that a floating object discharge port, a take-out port, etc. are unnecessary.

In both of the above-mentioned embodiments, the distribution and dispersion pipe protrudes from only one side of the mixing chamber, but if the flotation tank is large enough, the water to be treated will float to the surface when the distribution and dispersion pipe rotates 180 degrees. Since the separation has been completed, it is possible to attach the distributing pipe to the rotating cylinder (mixing chamber) at a phase of 180'', and in this case, the processing capacity is further expanded.

(Effects of the Invention) In the present invention, since the water to be treated flowing out from the mixing chamber is supplied to the liquid level of the flotation tank, the supplied water to be treated does not stir the inside of the flotation tank. Therefore, the flotation separation efficiency in the flotation tank is improved, the required surface area and water depth of the flotation tank are reduced, and the processing residence time is also shortened, resulting in a significant increase in the amount of water processed per unit volume of the flotation tank. It can be increased.

In addition, the installation angle of the guide plate that supplies the water to be treated to the surface of the flotation tank can be adjusted arbitrarily, so depending on the properties of the water to be treated, the guide plate can be positioned slightly away from the liquid surface or It has the effect of being able to supply it at any angle, such as at a position where it touches a surface.

[Brief explanation of drawings]

Figure 1 is a vertical sectional view of the entire assembled device of the present invention, Figure 2 is a plan view of the same, Figure 3 A, B, and C are sectional views of the distribution pipe, and Figure 4 is the installation state of the guide plate. FIG. 5 is a plan view showing another embodiment of the floating object removing means. l...Flotation tank 2...Mixing chamber 3...Treated raw water supply port 4...Pressurized water supply port 5...Treated raw water tank 6...Pressure tank 7...Treated water tank
8...Medical tank 9...Rotating cylinder 10
...Distribution spray pipe 11...Spraying port 12.
・・Spreading guide plate 13・・Mounting plate 14・
... Bracket 15 ... City axis 16 ...
- Long hole 17... Fixing bolt 19... Drive shaft 21... Drive gear 23... Chain 25... Bearing 27... Skim rake 29... Discharge rake 31... Floating object outlet 33... Sediment removal port: 15-... Partition plate 37... Gauge pipe 39... Discharge pipe 41-... Second skim rake

Claims (3)

[Claims] (1) A flotation tank, a mixing chamber in which treated raw water and pressurized water are supplied from the bottom, and treated water in which treated raw water and pressurized water are mixed in the mixing chamber, and suspended substances contained in the treated water are attached to air bubbles. a water supply means for supplying treated water from the upper part of the mixing chamber to the liquid surface of the flotation tank and adjusting the supply angle to an arbitrary angle; and a water collection port for the treated water provided at the bottom of the flotation tank;
A pressurized flotation separation device comprising a floating object removing means for removing floating objects floated and separated on the liquid surface of the flotation tank, and a water surface height holding means for maintaining the water surface height of the flotation tank at a predetermined height. Device. (2) The flotation tank is a tank with a circular plan view, and the water to be treated is supplied to a cylindrical mixing chamber provided in the center of the flotation tank and a rotating cylinder rotatably provided at the top of the mixing chamber. It consists of a distribution and dispersion pipe provided in the direction, a dispersion port formed along the length of the distribution and dispersion pipe, and a guide plate provided on the lower surface of the dispersion port of the distribution and dispersion pipe so that the installation angle can be adjusted. The floating object removal means includes a skim rake that scrapes floating objects floating on the liquid surface toward the peripheral wall of the flotation tank on the opposite side of the dispersion port of the distribution and dispersion pipe, and a skim rake provided at the tip of the distribution and dispersion pipe. Claim 1, comprising a discharge rake and a floating object discharge port provided in the flotation tank.
The pressurized flotation separation device described in . (3) The floating object removal means includes a suction cup provided on the opposite side of the dispersion port of the distribution pipe for removing floating objects by suction, and a skim rake provided to scrape up floating objects toward this suction cup. Claim 1 characterized in that
The pressurized flotation separation device described in .