KR100919367B1 - Flotation device using high efficiency tank for dissolving a gases into liquids - Google Patents

Abstract

PURPOSE: A flotation device using a high efficiency gas dissolving tank is provided to reduce maintenance and management cost by using a circulation water pump, and to increasing a dissolution rate of the air by dissolving the air in the circulation water. CONSTITUTION: A flotation device using a high efficiency gas dissolving tank includes a flotation tank(20), a minute air bubble generating device(70), a processed water collecting part(30), a concentration rate control valve(40), a circulation water pump(50), and a gas dissolving tank(60). The waste supplied from a flocculation basin(10) is flowed to the flotation tank. The minute air bubble generating device is formed on the bottom of a waste water inlet(22). The minute air bubble generating device generates bubbles in the waste water. The processed water is flowed to the processed water collecting part. The concentration rate control valve discharged a part of the processed water to the outside. The circulation water pump pressurizes a part of the processed water. A venture pipe is flowed on a location which is higher than the surface of pressurized water in the gas dissolving tank.

Description

Floating device using high efficiency tank for dissolving a gases into liquids}

The present invention relates to a flotation separator using a high-efficiency gas dissolving tank, which improves air dissolution efficiency by dissolving air in circulating water using a ventry tube, and separates flotation by forming a large amount of fine bubbles through a microbubble generating device. It relates to a flotation separation device using a high efficiency gas dissolution tank to improve the efficiency.

In the sewage and wastewater treatment, the flotation method is to remove the solid particles in the water by floating them on the surface.

Gravity injuries are applicable only to oils, such as oils, which are less dense than water, and injuries often mean bubble-injuries. Bubble-type floating method is a method of attaching bubbles to particles to be separated to increase the speed of remarkably, so that even if the particles are denser than water, the floating particles can be separated. When sufficient bubbles are attached to the suspended particles to be removed in this way, the floating separation speed can be increased to increase the removal speed of the suspended particles, and the concentration of suspended particles can be increased.

Although the solid-liquid separation treatment due to the above-mentioned injuries has many advantages, the solid-liquid separation in many sewage and wastewater treatments has been mainly used for separation by gravity sedimentation. This is because it was difficult to determine the gas-liquid ratio (A / S ratio) which acts as a major factor in flotation, that is, the rate of injection of air into suspended solids (SS) to be removed. There was also a reason that mechanical operation in the field was difficult. As a result, the treated water quality by the flotation method was worse than that by the sedimentation method.

1 is a conceptual view showing a conventional pressure floating device, the raw waste water treated in the chemical treatment tank 110 is mixed with the pressurized water discharged from the pressure melting tank 140 in accordance with the opening and closing of the pressure control valve 150, It is introduced into the separation tank 120. The raw wastewater introduced into the flotation separation tank 120 generates bubbles by air dissolved in the pressurized water, causing suspended particles to rise to the surface and is discharged to the outside by the scum removal device 122 to be removed. The treated water from which the suspended particles are removed is discharged into the treated water tank 130, and some of the treated water introduced into the treated water tank 130 is discharged as the treated water, and some is introduced into the pressurized melting tank 140 as the circulating water. Is done. The circulating water discharged from the treated water tank 130 is pressurized by the circulating water pump 142 together with the air supplied from the air ejector ejector 144 and introduced into the pressurized melting tank 140. The pressurized water introduced into the pressure dissolving tank 140 is mixed with the raw waste water by the pressure regulating valve 150 and introduced into the flotation separation tank 120 to generate fine bubbles to remove the suspended particles. By the above process, the suspended particles in the original waste water are continuously removed to discharge the purified treated water to the outside.

The process of pressurizing the circulating water using the circulating water pump 142 together with the air supplied from the air ejector 144 is generally made of high pressure of about 4 ~ 5 kg _f / cm ² because the high pressure pump When air is injected into the pump, cavitation occurs, which is the main cause of pump failure. In addition, there is a problem that it is difficult to control the amount of air dissolved in the pressurized water because there is no means for adjusting the amount of air injected into the circulating water pump 142.

In addition, the upper part of the pressurized melting tank 140 into which the pressurized water pressurized by the circulation water pump 142 is filled with pressurized water in the lower part of the pressurized water, and surplus air is discharged from the upper part to distinguish between the air and the pressurized water. The outlet 160 is further provided. There is a problem that the air is always unnecessarily discharged to the surplus air outlet 160 by the configuration as described above, the adjustment of the valve 146 for adjusting the water level of the pressure dissolving tank 140 is wrong, the air inside the pressure dissolving tank 140 If much air is mixed with the pressure regulating valve 150, so that the suspension of suspended particles is not made smoothly, and if the pressurized water is filled inside, the load of the circulating water pump 142 increases and the pressure regulating valve 150 Excessive pressurized water is released. Due to the operation method as described above, the conventional pressurization apparatus has a problem that it is difficult to adjust the gas-liquid ratio (A / S ratio).

The present invention has been made in order to solve the above problems, the object of the present invention is that only the circulating water flows in the circulating water pump, so that the circulating water pump is not overwhelming, and efficient gas supply and ventry pipe are applied in the gas melting tank. The present invention provides a flotation separation device capable of efficiently separating flotation by generating a large amount of fine bubbles using a microbubble generator.

The flotation separator using the high-efficiency gas dissolving tank of the present invention includes a flotation tank into which raw waste water flows from a flocculation tank; A microbubble generating device for generating microbubbles in the raw wastewater which is provided at a lower portion of the raw wastewater inlet on one side of the floating tank; A treatment water collection unit provided at a lower portion of the floating tank to introduce the treatment water from which the suspended particles are removed; A concentration rate control valve provided at an outer upper side of the floating tank to discharge a portion of the treated water introduced through the treated water collection unit to the outside; A circulating water pump for pressurizing a portion of the treated water introduced through the treated water collection unit; And a gas dissolving tank for receiving pressurized water formed by dissolving air in the circulating water pressurized by the circulating water pump and supplying the formed pressurized water to the microbubble generating device. Characterized in that it comprises a.

The microbubble generating device is characterized in that the pressurized water supplied from the gas dissolution tank passes through the ventry tube and generates microbubbles by shear force.

The floating tank is further characterized in that the scum removing device for removing the scum floating on the water surface by the microbubble generating device.

The floating tank is characterized in that the partition is further formed so that the suspended particles in the incoming wastewater is moved to the other side after the suspended particles are removed by the microbubbles generated by the microbubble generator.

The enrichment rate control valve has an inner pipe in which a plurality of inner outlets are formed side by side along the longitudinal direction, and an outer outlet screwed with the outer surface of the inner pipe and connected to one of the plurality of inner outlets by screwing. Characterized in that consisting of the outer cap.

The gas dissolution tank is characterized in that the ventry tube is formed to dissolve the air supplied by the compressor on the circulation water passage through which the pressurized water flowing into the gas dissolution tank by the circulation water pump.

The venturi tube of the gas dissolving tank is formed at a position higher than the pressurized water surface inside the gas dissolving tank.

The gas dissolution tank is further characterized in that the water level control sensor for opening and closing the circulation water passage and the air passage in accordance with the water level.

Floating separator using high-efficiency gas dissolving tank of the above structure dissolves air in circulating water by using a ventrile pipe, so the rate of dissolution of air is increased, and a smaller capacity circulating water pump can be used. This has a decreasing effect.

In addition, the microbubbles generated in the microbubble generating device are small, uniform, and laminar flow, thus increasing the efficiency of attaching microbubbles to suspended matter in the wastewater, thereby increasing the floating efficiency of the suspended matter. Purification efficiency is improved.

1 is a conceptual view showing a conventional pressurized floating apparatus.

Figure 2 is a front view showing a flotation separator of the present invention.

Figure 3 is a conceptual diagram showing the treated water collection unit and the concentration control valve of the present invention.

Figure 4 is a cross-sectional view showing a concentration control valve of the present invention.

5 is a cross-sectional view showing a gas dissolution tank of the present invention.

Figure 6 is a cross-sectional view showing a microbubble generating device of the present invention.

7 is a graph showing the bubble size according to the termination speed by the microbubble generating device of the present invention.

Figure 8 is a graph showing the gas dissolution rate according to the operating pressure by the gas dissolution tank of the present invention.

** Description of the symbols for the main parts of the drawings **

10: flocculation tank

20: floating tank 22: raw wastewater inlet

24: bulkhead 26: scum removal device

30: treated water collection unit

40: concentration control valve 42: internal pipe

44: outer cap 42a, 44a: inner, outer outlet

50: circulating water pump 54: ventry pipe

60: gas melting tank 62: compressor

66: water level sensor

70: micro bubble generator 72: ventry tube

Hereinafter, the flotation separator using the high efficiency gas dissolving tank as described above will be described in detail with reference to the accompanying drawings.

Figure 2 is a schematic view showing the flotation separator of the present invention, Figure 3 is a conceptual view showing the treated water collection unit and the concentration control valve of the present invention, Figure 4 is a cross-sectional view showing the concentration control valve of the present invention, 5 is a cross-sectional view showing a gas dissolving tank of the present invention, Figure 6 is a cross-sectional view showing a microbubble generating device of the present invention, Figure 7 is a graph showing the bubble size according to the termination speed by the microbubble generating device of the present invention 8 is a graph showing the gas dissolution rate according to the operating pressure by the gas dissolution tank of the present invention.

Floating separation apparatus of the present invention, as shown in Figures 2 to 5, the floatation tank 20 to which the raw waste water from the flocculation tank 10; A microbubble generating device (70) for generating microbubbles in the raw wastewater introduced by being provided under the raw wastewater inlet (22) on one side of the floating tank (20); A treatment water collection unit 30 provided at a lower portion of the floating tank 20 to receive the treatment water from which the suspended particles are removed; A concentration rate control valve 40 disposed at an outer upper side of the floating tank 20 to discharge a portion of the treated water introduced through the treated water collecting unit 30 to the outside; A circulating water pump 50 for pressurizing some of the treated water introduced through the treated water collecting unit 30; And a gas dissolving tank 60 for receiving pressurized water formed by dissolving air in the circulating water pressurized by the circulating water pump 50 and supplying the formed pressurized water to the microbubble generating device 70. It is made, including.

The floating tank 20 has a wastewater inlet 22 through which the wastewater collected in the agglomeration tank 10 is introduced at one side, and is introduced from the gas dissolution tank 60 at the lower portion of the wastewater inlet 22. Micro bubble generator 70 for generating micro bubbles by the pressurized water is provided. Suspended particles in the wastewater introduced through the wastewater inlet 22 are moved to the other side of the floating tank 20 after the floating is smoothly made to the surface by the microbubbles generated in the microbubble generator 70, The partition wall 24 having a predetermined height is formed outside the micro bubble generator 70. The scum removing device 26 is provided on the floating tank 20 to remove the scum layer formed by the suspended particles in the original waste water by the microbubble generating device 70. As a result, the scum skimmer 26a is rotated. As a result, the scum layer is moved in one direction and discharged through the scum discharge port 26b.

The lower portion of the floating tank 20, as shown in Figure 3, the treated water collection unit 30 for discharging the outside the treated water from which suspended particles in the original waste water is removed. Some of the treated water introduced by the treated water collection unit 30 is discharged to the outside through the concentration control valve 40, a part is circulated by the circulating water pump 50 is formed of pressurized water. The concentration control valve 40 is screwed with the inner pipe 42 and the outer surface of the inner pipe 42 is formed with a plurality of inner discharge port 42a side by side in the longitudinal direction as shown in FIG. It consists of an outer cap 44 which is formed by the outer discharge port 44a in communication with one of the plurality of inner discharge ports (4a) by the coupling. When the outer cap 44 is rotated to communicate the outer outlet 44a and the inner outlet 42a with each other, the treated water is discharged to the outside through the treated water collection tank 46. Rotating the outer cap 44 due to the inner discharge port 42a formed at different heights in the longitudinal direction of the inner pipe 42 to communicate with the inner discharge port 42a, 44a, the internal discharge port is in communication The level of the treated water accommodated in the floatation tank 20 can be adjusted according to the height of 42a, and the thickness of the scum layer formed on the upper portion of the floated tank 20 can also be varied according to the level of the treated water. It can be effective.

Some of the treated water introduced through the treated water collecting unit 30 is pressurized by the circulating water pump 50 and introduced into the gas dissolving tank 60. The circulating water flowing into the gas dissolving tank 60 passes through a ventry tube 54 formed on the circulating water passage 52 as shown in FIG. 5. Since the circulating water passing through the ventry pipe 54 has a faster flow rate and a lower pressure, the air supplied by the compressor 62 above the gas dissolution tank 60 is sucked into the ventry pipe 54 by a pressure difference. To dissolve in circulating water. As the pressurized water in which air is dissolved using the ventry pipe 54 is formed as described above, a circulation water pump having an operating pressure of 2 to 3 kg _f / cm ² lower than that of the conventional flotation separation system can be used. Has the effect of decreasing. In the above, the ventry pipe 54 is provided above the pressurized water surface to allow the inflow of air through the ventry pipe 54, and the air is supplied by the compressor 62 according to the amount of air dissolved in the circulating water. There is an effect that no waste of air occurs. In addition, the water level control sensor 66 is further provided inside the gas dissolving tank 60, when the air is dissolved in the circulating water to be introduced to increase the water level, the water level control sensor 66 is supplied by the compressor 62 By opening the air passage 64 there is an effect that can maintain a constant water level in the gas dissolution tank 60.

The microbubble generating device 70 is formed of a ventry tube 72 as shown in FIG. 6 so that the pressurized water supplied from the gas dissolution tank 60 passes through the ventry tube 72 to generate microbubbles by shear force. do. The pressurized water supplied from the gas dissolution tank 60 passes through the microbubble generating device 70 and the passage 72b is instantaneously narrowed due to the ventry pipe 72 to increase the flow rate, and again flow rate at the opening 72a. The negative pressure flow 76 is formed at the front end of the slow and rapidly progressing pressurized water 74, and as a result, the shear force is generated to form microbubbles. As described above, when the micro bubble generator 70 using the ventry tube 72 is applied, sufficient microbubbles are generated even when the minimum diameter of the ventry tube 72 is increased, thereby reducing clogging caused by foreign substances. There is. In addition, since the micro-bubbles generated by the shear force using the ventry tube 72 floats in a substantially laminar flow form, there is an advantageous effect on mixing and flotation when mixing with the raw wastewater. In addition, if sufficient gas is dissolved in the pressurized water supplied from the gas dissolving tank 60, the gas dissolved in the pressurized water is degassed by a slight physical impact such as a collision with the original waste water under atmospheric pressure, and is formed into a fine bubble to separate more flotation. Even more effective.

The operation of the flotation apparatus of the above configuration will be described. Some of the treated water introduced into the treated water collecting unit 30 below the floating tank 20 is discharged to the outside through the treated water collecting tank 46 by adjusting the concentration control valve 40, and some of the treated water is circulated. Pressurized by the pump 50 is introduced into the gas dissolution tank 60. The circulating water flowing into the gas dissolving tank 60 passes through the ventry tube 54 and the flow rate is increased and the pressure is lowered, so that the air in the upper gas dissolving tank 60 is sucked in and dissolved to form pressurized water. Pressurized water formed in the gas dissolution tank 60 is generated by passing through the microbubble generating device 70 provided in the lower portion of the wastewater inlet 22 flowing into the flotation tank 20 from the flocculation tank 10. The microbubbles are attached to the suspended particles in the original wastewater and float to the surface to form a scum layer. The scum layer is moved in one direction by the scum skimmer 26a of the scum removal device 26 provided above the floating tank 20 and discharged to the scum discharge port 26b. The treated water from which the suspended particles are removed by the above process is discharged to the outside through the treated water collecting unit 30 or continuously circulates the above cycle as the circulating water to serve to clean the original wastewater.

7 shows the results of analyzing and photographing the microbubbles generated and floated through the microbubble generating device 70 as described above and using the equations of motion of the particles. The equation of motion of a particle is expressed as inertia force = buoyancy-gravity-resistance (friction) in the case of bubbles.

----------- Equation 1

The microbubbles generated as a result of the experiments were measured from several μm to several tens of μm, mainly in the range of 5 to 30 μm, and showed a very small bubble size and uniform composition, which is very advantageous for injury.

The air dissolution rate in the gas dissolving tank 60 as described above may be divided into total and partial pressures depending on the type of pressure in the case of a pressurized part, and the air amount is the ratio of air / particle by using Equation 2 (A / S ratio).

--- Equation 2

The A / S ratio is not only an important factor in determining the efficiency of the pressurization part but also an important factor in terms of operation and maintenance. One result. Conventional pressurization apparatus is generally designed to the air dissolution efficiency of about 50%, the operation pressure is also operated at 5 kg _f / cm ² . This is because the dissolution efficiency of the air actually supplied is low, and it is reflected in the design about 50% in consideration of the air discharged through the excess air outlet. In the case of the flotation separator of the present invention, the dissolution efficiency is 90% or more, and even if the operating pressure is changed to 1 to 5 kg _f / cm ² , there is no significant change in the dissolution efficiency. In order to achieve this, it can be seen that sufficient air supply is possible even when driving at a level 1/2 of the pressure used in the conventional flotation apparatus. In other words, even if the pressure of the circulating water pump 50 is operated at a level of 1/2, the A / S ratio can be satisfactorily satisfied, so that a smaller capacity circulating water pump can be used, thereby reducing the equipment cost.

Claims (8)

Floating tank 20 into which the raw wastewater flows from the coagulation tank 10; A microbubble generating device (70) for generating microbubbles in the raw wastewater introduced by being provided under the raw wastewater inlet (22) on one side of the floating tank (20); A treatment water collection unit 30 provided at a lower portion of the floating tank 20 to receive the treatment water from which the suspended particles are removed; A concentration rate control valve 40 disposed at an outer upper side of the floating tank 20 to discharge a portion of the treated water introduced through the treated water collecting unit 30 to the outside; A circulating water pump 50 for pressurizing some of the treated water introduced through the treated water collecting unit 30; And a gas dissolving tank 60 for receiving pressurized water formed by dissolving air in the circulating water pressurized by the circulating water pump 50 and supplying the formed pressurized water to the microbubble generating device 70. It consists of The concentration control valve 40 is screwed to the outer surface of the inner pipe 42 and the inner surface of the outer cap 44, a plurality of inner discharge ports (42a) side by side along the longitudinal direction of the inner pipe (42) The outer discharge hole 44a formed in the inner pipe 42 and formed in the outer cap 44 communicates with one of the plurality of inner discharge holes 42a formed in the inner pipe 42. The gas dissolving tank 60 dissolves the air supplied by the compressor 62 on the circulation water passage 52 through which pressurized water flowing into the gas dissolving tank 60 flows by the circulation water pump 50. Venturi pipe 54 to be formed at a position higher than the pressurized water surface in the gas dissolution tank 60, the water level control sensor 66 for opening and closing the circulating water passage 52 and the air passage 64 according to the water level Floating separation apparatus using a high-efficiency gas dissolution tank comprising a) provided. The method of claim 1, The microbubble generating device 70 is a floating separation device using a high-efficiency gas dissolving tank, characterized in that the pressurized water supplied from the gas dissolving tank 60 passes through the ventry tube 72 and generates micro bubbles by shearing force. . The method of claim 2, The floating tank 20 is separated from the floating tank using a highly efficient gas dissolving tank, characterized in that the scum removing device 26 for removing the scum floating on the water surface by the micro-bubble generating device 70 is further provided. Device. The method of claim 3, wherein The floating tank 20 is further formed with a partition wall 24 to allow the suspended particles in the incoming wastewater to be moved to the other side after the suspended particles are removed by the microbubbles generated by the microbubble generator 70. Floating separation device using a high-efficiency gas dissolution tank characterized in that. delete delete delete delete