JP2009119338A - Dissolved air floatation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dissolved air floatation system which can prevent bad odors from the system by using no equipment or by using only very simple equipment. <P>SOLUTION: Flocculation-treated water flows into a mixing chamber 20 through an outflow port 16 and an ascending passage 27. Water is pulled out from the lower part of a floatation chamber 30 through piping 21, and a gas from a floatation tank 4 is pressurized and dissolved in the water by a pressurized water production device 22 to obtain pressurized water. This pressurized water is supplied to a nozzle 23. The flocculation-treated water and the pressurized water are sufficiently mixed, and fine bubbles generated from the pressurized water adhere sufficiently to coagulated flocs. The flocs are supplied to the floatation chamber 30 to be efficiently separated by floatation. A cover 40 is installed so as to cover the floatation tank 4 from above, and piping 41 is laid so as to introduce the gas in the upper part of the floatation tank 4 to the pressurized water production device 22. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to an apparatus for subjecting SS to water containing suspended solids (SS) by pressure levitation separation, and more particularly, to a pressure levitation apparatus that utilizes gas generated in a levitation tank as a gas source of pressurized water. .

As a treatment apparatus for water containing SS, there is a pressurized levitation apparatus that feeds pressurized water separately or mixed to raw water to a floating tank, and adsorbs SS in the raw water to micro air in the tank to float on the water surface. (For example, Patent Documents 1 and 2 below).
JP 2006-218281 JP 2007-196116 A

  A gas derived from pressurized water or water to be treated is generated from the levitation tank of the pressurized levitation device. This gas has caused odors from the pressurized levitation device. To prevent this, a separate odor gas treatment facility was required.

  It is an object of the present invention to provide a pressurized levitation device that can prevent odors from a pressurized levitation device without using an odor gas treatment facility or by using an extremely simple odor gas treatment facility. To do.

  The pressurized flotation device according to claim 1 includes a pressurized water production device for producing pressurized water in which a gas is pressurized and dissolved in water, and a floating tank into which the pressurized water and the water to be treated are introduced separately or mixed. The pressurized levitation apparatus has a means for guiding the gas in the upper part of the levitation tank to the pressurized water production apparatus.

  According to a second aspect of the present invention, there is provided a pressurized levitation apparatus according to the first aspect, wherein a cover surrounding the upper portion of the levitation tank is provided, and the gas in the cover is guided to the pressurized water producing apparatus. Is.

  According to a third aspect of the present invention, the pressurized levitation apparatus according to the second aspect further includes a communication portion that communicates the inside of the cover with the atmosphere.

  According to a fourth aspect of the present invention, there is provided the pressurization flotation device according to the third aspect, wherein the communicating portion is provided with an opening / closing means that is opened when the pressurized water production apparatus is in operation and closed when the pressurized water production apparatus is stopped. It is a feature.

  The pressure levitation apparatus according to claim 5 is the flocculation treatment tank according to any one of claims 2 to 4, further comprising a flocculation treatment tank for supplying the flocculation treatment water as the treated water to the levitation tank. The gas flow path which guides the gas of the upper part of this to the said cover or the said pressurized water manufacturing apparatus is provided.

  In the pressurized levitation apparatus of the present invention, the gas containing odor generated in the levitation tank by being separated from the water in the levitation tank is guided to the pressurized water production apparatus, so that the odor is outside the pressure levitation apparatus. Leakage is prevented or suppressed.

  As described in claim 2, by providing a cover surrounding the upper part of the levitation tank and guiding the gas in the cover to the pressurized water production apparatus by piping or the like, leakage of odor outside the pressurized levitation apparatus is sufficiently prevented. .

  When considering the gas balance of a typical levitation tank, gas is dissolved in the treated water from the levitation tank, and bubbles are attached to the separated scum. The amount of gas to be dissolved is less than the amount of gas dissolved in pressurized water and brought into the levitation tank. For this reason, when the pressurized levitation apparatus including the levitation tank with the cover is operated as in claim 2, the inside of the cover becomes negative pressure. Therefore, it is preferable that the interior of the cover and the atmosphere are communicated as in claim 3 so that the atmosphere flows into the cover during operation of the pressurized water producing apparatus and the negative pressure is eliminated.

  In order to prevent the odor from being diffused into the atmosphere, a check valve, an on-off valve, or the like may be provided at the communication portion. In particular, by providing an open / close means in the communicating portion that is open when the pressurized water producing apparatus is in operation and closed when the operation is stopped, odor emission to the atmosphere can be reliably prevented.

  When the coagulated water is introduced into the levitation tank as the water to be treated, odor-containing gas may be generated in the coagulation tank. Therefore, as described in claim 5, odor from the coagulation treatment layer can be prevented by introducing the gas in the upper part of the coagulation treatment tank to the pressurized water production apparatus via the floating tank or directly.

  Hereinafter, embodiments will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view in the longitudinal direction of a pressure levitation separator according to an embodiment.

  The inside of the tank body 3 having a substantially rectangular shape in plan view is partitioned by the partition wall 1 and the partition wall 2, so that the aggregation tank 10, the mixing chamber 20, and the floating separation chamber 30 are formed in this order. In this embodiment, the mixing tank 20 and the floating separation chamber 30 constitute the floating tank 4. The partition wall 1 and the partition wall 2 are extended in the short side direction, that is, the width direction of the tank body 3.

  At the lower part of the partition wall 1, an outlet 16 for the agglomerated treated water is formed. The upper end of the partition wall 1 extends upward from the water surface of the tank body 3 and the aggregation tank 10.

  The partition wall 2 is erected from the bottom surface of the tank body 3, and the upper end thereof is lower than the water surface of the tank body 3.

  Each wall 1, 2 is connected to both side surfaces of the tank body 3.

  The raw water is introduced into the coagulation tank 10 through the raw water pipe 11, and the coagulant and the alkali agent can be supplied through the supply pipes 12 and 13. A pH meter (not shown) for detecting the pH of water in the coagulation tank 10 is installed, and the alkaline agent injection pump (not shown) is operated so that the detected value of the pH meter falls within a predetermined range.

  As the flocculant, various organic flocculants as well as inorganic flocculants such as PAC can be used, and two or more flocculants may be used in combination. A predetermined amount of the flocculant is added by a flocculant drug pump (not shown). The water in the agglomeration tank 10 is gently agitated by the agitator 15 and agglomerated.

  The agglomerated water flows into the mixing chamber 20 through the outlet 16 and the rising channel 17. A guide plate 18 is provided in the mixing chamber 20 so as to project from the partition wall 1 toward the partition wall 2 above the ascending flow path 17. Therefore, the agglomerated water is changed in the flow direction to a substantially horizontal direction by the guide plate 18 and flows along the bottom surface of the tank body 3 in the mixing chamber 20. A nozzle 23 for discharging pressurized water is provided in the bottom surface of the tank body 3 in the center in the width direction and relatively close to the partition wall 2. The tip of the nozzle 23 slightly protrudes from the bottom surface of the tank body 3, but is not limited to this.

  In this embodiment, water is taken out from the lower part of the floating separation chamber 30 through the pipe 21, the gas from the floating tank 4 is pressurized and dissolved in the pressurized water production apparatus 22 to form pressurized water, and this pressurized water is supplied to the nozzle 23. Supply. Here, although the water for pressurized water is taken out from the lower part in the levitation separation chamber 30, the working water or clean water from the pipe 35 described later may be taken out and used, and is not particularly limited.

  In this embodiment, the nozzle 23 is disposed in a vertically lower region of an inclined partition upper portion 2b described later. In this embodiment, only one nozzle 23 is provided in the center of the bottom surface of the tank body 3 in the width direction, but a plurality of nozzles 23 may be provided.

  The agglomerated water from the agglomeration tank 10 and the pressurized water from the nozzle 23 rise mainly along the vicinity of the center in the width direction of the partition wall 2 while being mixed. The partition wall 2 is a vertical part 2a that is substantially vertical (preferably within ± 10 ° with respect to the vertical surface) except for the upper part 2b, and the upper part 2b is inclined toward the partition wall 1 side.

  The upward flow flows substantially vertically upward along the vertical portion 2 a of the partition wall 2. Next, the upward flow is guided by the inclined partition upper part 2 b to change the flow direction toward the partition wall 1, and becomes a downward flow that descends along the partition wall 1 when reaching the vicinity of the partition wall 1. The downward flow that has flowed to the lower part of the partition wall 1 flows toward the partition wall 2 on the bottom surface of the tank body 3 while joining with the agglomeration treatment water from the aggregation tank 10. In this way, a circulating flow in the vertical direction is formed in the mixing chamber 20. During the circulation, the agglomerated water and the pressurized water are sufficiently mixed, and fine bubbles generated from the pressurized water sufficiently adhere to the agglomerated floc.

  After the bubbles are sufficiently attached to the floc in this way, the floc is supplied to the floating separation chamber 30, and the floc is efficiently floated and separated.

  The floated flock is discharged to a sludge receiving chamber 32 by a scraper 31 such as a skimmer or a scraper and taken out via a discharge pipe 33.

  The sludge that has settled in the floating separation chamber 30 is discharged through the pipe 34.

  The clean water is extracted from the midway in the vertical direction of the floating separation chamber 30 by the pipe 35 and is taken out via the water level adjusting tank 36 and the extraction pipe 37. The water level adjustment tank 36 is for adjusting the water level in the tank body 3.

  In this embodiment, a cover 40 is installed so as to cover the floating tank 4 including the mixing chamber 20 and the floating separation chamber 30 from above, and the space above the water surface in the floating tank 4 is isolated from the atmosphere. A pipe 41 is routed so as to guide the gas in the upper part of the floating tank 4 to the pressurized water production apparatus 22. When the pressurized water production apparatus 22 is operated, the gas in the levitation tank 4 is dissolved in water in the pressurized water production apparatus 22. Thus, since the gas generated in the levitation tank 4 is circulated, the odor does not leak to the outside, and the odor from the pressurized levitation device can be prevented or suppressed without using the odor gas treatment equipment. .

  FIG. 2 is a cross-sectional view of a pressure levitation apparatus according to a second embodiment.

  In this embodiment, the cover 40 </ b> A extends to the upper side of the aggregation tank 10 and isolates the space above the water surface of the aggregation tank 10 from the atmosphere. A ventilation gap is provided between the upper end of the partition wall 1 and the cover 40A.

  For this reason, the gas of the upper part in the coagulation tank 10 is also sent to the pressurized water manufacturing apparatus 22 via the floating tank 4, and the odor from the coagulation tank 10 is also prevented.

  In FIG. 2, the gas from the coagulation tank 10 is sent to the pressurized water production apparatus 22 via the levitation tank 4, but may be sent directly to the pressurized water production apparatus 22 via a pipe.

  FIG. 3 shows a pressurized levitation apparatus of FIG. 1 in which a communication pipe 42 is provided for communicating the space below the cover 40 to the atmosphere, and an open / close valve 43 is provided on the communication pipe 42.

  As described above, in the pressurized levitation apparatus of FIG. 1, when the pressurized water production apparatus 22 is operated, a part of the gas sent to the levitation tank 4 along with the pressurized water is dissolved in the treated water or bubbles in the sludge. Adhere as. For this reason, in the pressurized levitation device of FIG. 1, the amount of gas returned by the pipe 41 is smaller than the amount of gas sent to the levitation tank 4 together with the pressurized water, and the inside of the levitation tank 4 is negative when the pressurized water production apparatus 22 is operated. Become pressure.

  In the pressurized levitation apparatus of FIG. 3, the negative pressure can be eliminated by opening the on-off valve 43 and allowing the atmosphere to flow in during the operation of the pressurized water production apparatus 22. Moreover, when the operation of the pressurized water production apparatus 22 is stopped, the on-off valve 43 is closed to prevent the odor gas from being diffused to the atmosphere.

  In order to prevent the odor gas from diffusing, a backflow prevention means such as a check valve or a sealing trap may be provided in place of the on-off valve 43. An air filter or the like may be provided instead of the backflow prevention means. Further, when the pipe diameter of the communication pipe 42 is small, the backflow prevention means may be omitted.

  As shown in FIG. 4, the open / close valve 43 may be configured to open and close in conjunction with the operation of the pressurized water producing apparatus 22. Reference numeral 44 denotes a signal line for this purpose.

  In the embodiment in which the cover 40A extends to the agglomeration tank 10 as shown in FIG. 2, atmospheric communication means may be provided as shown in FIGS.

  Hereinafter, an embodiment of a pressurized levitation apparatus having a feed well will be described with reference to FIGS. FIG. 5 is a longitudinal sectional view of the pressure levitation apparatus according to this embodiment.

  In this pressurized levitation device, an inner tank 52 is provided along the inner periphery of the circular tank body 51 of the levitation tank 50, and the treated water can rise between the tank body 51 and the inner tank 52. A feed well 60 is erected at the center of the tank body 51, a raw water inflow pipe 53 is connected to the feed well 60 in a tangential direction, and a pressurized water producing apparatus is connected to the raw water inflow pipe 53 via a pressurized water inflow pipe 54. 70 is connected. In this embodiment, the raw water is coagulated water from the coagulation tank 90 (not shown in FIG. 5; see FIG. 6 described later).

  The raw water and the pressurized water flow into the levitation tank through the feed well 60 from the inflow pipes 53 and 54, and solid-liquid separation is performed. The treated water goes around the lower end of the inner tank 52, rises between the inner tank 52 and the tank body 51, and is discharged from the treated water trough 55 to the treated water tank 80. On the other hand, the floating scum is scraped by a scum rake (skimmer) 56, dropped into a scum box 58, and discharged from a discharge port (not shown). Reference numeral 57 denotes a motor for driving the scum rake 56. A drainage pipe 59 is connected to the bottom of the tank body 51.

  In this embodiment, water is taken out from the treated water tank 80 through the pipe 81, and the gas from the floating tank 50 is pressurized and dissolved in the pressurized water manufacturing apparatus 70 to form pressurized water, and this pressurized water is supplied to the pipe 54. The pipe 81 is provided with a flow meter 82. Here, treated water is used as water for pressurized water, but industrial water or the like may be used and is not particularly limited.

  In this embodiment, a cover 71 is installed so as to cover the floating tank 50 from above, and the space above the water surface in the floating tank 50 is isolated from the atmosphere. A pipe 72 is routed so as to guide the gas in the upper part of the floating tank 50 to the pressurized water production apparatus 70. The pipe 72 is provided with a flow meter 73. When the pressurized water production apparatus 70 is operated, the gas in the levitation tank 50 is dissolved in water in the pressurized water production apparatus 70. Thus, since the gas generated in the levitation tank 50 is circulated, the odor does not leak to the outside, and the odor from the pressurized levitation device can be prevented or suppressed without using the odor gas treatment equipment. .

  FIG. 6 is a cross-sectional view of a pressurized levitation apparatus in which the gas in the coagulation tank 90 is also sent to the pressurized water production apparatus 70.

  The raw water is introduced into the coagulation tank 90 through the raw water pipe 91, and the coagulant and the alkali agent can be supplied through the supply pipes 92 and 93. A pH meter (not shown) for detecting the pH of water in the coagulation tank 90 is installed, and an alkaline agent injection pump (not shown) is operated so that the detected value of the pH meter falls within a predetermined range.

  As the flocculant, various organic flocculants as well as inorganic flocculants such as PAC can be used, and two or more flocculants may be used in combination. A predetermined amount of the flocculant is added by a flocculant drug pump (not shown). The water in the coagulation tank 90 is gently agitated by the agitator 94 and coagulated.

  An upper cover 95 of the coagulation tank 90 is installed, and a space above the water surface of the coagulation tank 90 is isolated from the atmosphere. The upper part of the aggregation tank 90 and the upper part of the levitation tank 50 are communicated with each other by a pipe 96.

  For this reason, the gas in the upper part in the coagulation tank 90 is also sent to the pressurized water production apparatus 70 via the pipe 96 and the floating tank 50, and the odor from the coagulation tank 90 is also prevented.

  In FIG. 6, the gas from the coagulation tank 90 is sent to the pressurized water production apparatus 70 via the floating tank 50, but may be sent directly to the pressurized water production apparatus 70 via a pipe.

  FIG. 7 shows a pressurized levitation apparatus of FIG. 6 in which a communication pipe 97 is provided for communicating the space below the cover 71 to the atmosphere, and an open / close valve 98 is provided on the communication pipe 97.

  In the pressurized levitation apparatus shown in FIG. 7, the negative pressure in the levitation layer 50 can be eliminated by opening the on-off valve 98 and allowing the atmosphere to flow in during the operation of the pressurized water production apparatus 70. Further, by closing the on-off valve 98 when the operation of the pressurized water production apparatus 70 is stopped, the odor gas is prevented from being diffused to the atmosphere.

  In order to prevent such odor gas from being diffused, a backflow prevention means such as a check valve or a sealing trap may be provided in place of the on-off valve 98. An air filter or the like may be provided instead of the backflow prevention means. In addition, when the diameter of the communication pipe 97 is small, the backflow prevention means may be omitted.

  As shown in FIG. 8, the on-off valve 98 may be configured to open and close in conjunction with the operation of the pressurized water producing apparatus 70. Reference numeral 99 denotes a signal line for this purpose.

  In the present invention, as the pressurized water production apparatus, for example, a vortex pump system or a compressor system can be adopted.

  FIG. 9 (a) is a schematic view of a vortex pump type pressurized water production apparatus 22A. In this method, the water from the pipe 21 or the pipe 81 and the gas from the pipe 41 or the pipe 72 are mixed and sent to the dissolution tank 102 by the vortex pump 101 to sufficiently mix the gas and liquid under pressure. Water and gas sufficiently mixed in the dissolution tank 102 are sent to the gas-liquid separation tank 103 via the pipe 104, and when surplus gas is generated, the surplus gas is vaporized in the levitation tank via the pipe 105. Return to the department or process separately to dissipate into the atmosphere. Pressurized water sufficiently containing gas is sent from the gas-liquid separation tank 103 to the nozzle 23 or the inflow pipe 54. The dissolution tank 102 may be omitted, and water and gas may be introduced into the gas-liquid separation tank 103 by the vortex pump 101.

  FIG. 9B is a schematic diagram of a compressor type pressurized water production apparatus 22B. In this system, water from the pipe 21 or 81 is sent to the gas-liquid separation tank 103 by the pump 107, and gas from the pipe 41 or 72 is sent to the gas-liquid separation tank 103 by the compressor 108 to separate the gas and liquid. Water and gas are mixed in the tank 103 under pressure. When surplus gas is generated in the gas-liquid separation tank 103, the surplus gas is returned to the gas phase part of the levitation tank via the pipe 105 or separately processed and diffused into the atmosphere. Pressurized water sufficiently containing gas is sent from the gas-liquid separation tank 103 to the nozzle 23 or the inflow pipe 54.

  In the present invention, ozone-containing pressurized water may be obtained by introducing ozone gas into the pressurized water production apparatus. In this way, even when an abnormal odor is generated from raw water or floating scum, the odor component can be decomposed and the odor can be suppressed.

It is a longitudinal cross-sectional view of the pressurization levitating apparatus which concerns on 1st Embodiment. It is a longitudinal cross-sectional view of the pressurization levitating apparatus which concerns on 2nd Embodiment. It is a longitudinal cross-sectional view of the pressurization levitating apparatus which concerns on 3rd Embodiment. It is a longitudinal cross-sectional view of the pressurization levitating apparatus which concerns on 4th Embodiment. It is a longitudinal cross-sectional view of the pressurization levitating apparatus which concerns on 5th Embodiment. It is a longitudinal cross-sectional view of the pressurization levitating apparatus which concerns on 6th Embodiment. It is a longitudinal cross-sectional view of the pressurization levitating apparatus which concerns on 7th Embodiment. It is a longitudinal cross-sectional view of the pressurization levitating apparatus which concerns on 8th Embodiment. It is a schematic diagram which shows the pressurized water manufacturing apparatus applicable to this invention, (a) A figure shows a eddy current pump type pressurized water manufacturing apparatus, (b) figure shows a compressor type pressurized water manufacturing apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Partition wall 2 Partition 3 Tank body 4 Floating tank 10 Aggregation reaction chamber 15 Stirrer 16,16 ', 51 Outlet 20 Mixing chamber 22,22A, 22B Pressurized water production apparatus 23 Nozzle 30 Floating chamber 31 Scraper 40 Cover 50 Floating Tank 51 Tank body 52 Inner tank 53 Raw water inflow pipe 54 Pressurized water inflow pipe 55 Treated water trough 56 Scum rake (skimmer)
58 Scum box 60 Feed well 70 Pressurized water production equipment 71 Cover

Claims (5)

A pressurized water production apparatus for producing pressurized water in which gas is dissolved under pressure in water;
In a pressurized levitation apparatus having a levitation tank into which pressurized water and treated water are introduced separately or mixed,
A pressurized levitation apparatus comprising means for guiding the gas in the upper part of the levitation tank to the pressurized water production apparatus.   2. The pressurized levitation apparatus according to claim 1, wherein a cover surrounding the upper part of the levitation tank is provided, and the gas in the cover is guided to the pressurized water production apparatus.   3. The pressurized levitation apparatus according to claim 2, further comprising a communication portion that communicates the inside of the cover with the atmosphere.   4. The pressurized levitation apparatus according to claim 3, wherein the communicating portion is provided with opening / closing means that is opened when the pressurized water producing apparatus is in operation and closed when the pressurized water producing apparatus is stopped. In any 1 item | term of the Claims 2 thru | or 4, the coagulation treatment tank which supplies coagulation process water as the said to-be-processed water to the said levitation tank is provided,
A pressurized levitation apparatus, characterized in that a gas flow path is provided for guiding the gas in the upper part of the coagulation treatment tank to the inside of the cover or the pressurized water production apparatus.

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