JP2010069387A - Water treatment apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To dispense with a pump for bubble atomizing operation, and to stably supply ozone microbubbles at a low cost. <P>SOLUTION: A water treatment apparatus includes microbubble generators 10-13 for introducing ozone-containing gas to generate microbubbles in water to be treated in an ozone tank, a flowmeter 19 for measuring the flow rate of the water to be treated, a water quality meter 20 for measuring the water quality of the water to be treated, and a controller 21 for carrying out ozone treatment of the water to be treated from the measured values of the flowmeter or the water quality meter. The microbubble generator includes a bubble injection portion formed in a hollow disk shape and bored with a plurality of bubble injection holes, and a rotating shaft for receiving turning force of a motor to rotate the bubble injection portion. The bubbles generated from the bubble injection holes are torn by shearing force generated by rotating the bubble injection portion to generate the fine bubbles of the ozone-containing gas in the ozone tank. The controller 21 carries out at least one of the revolution number control of the bubble injection portion and the flow rate control of the ozone-containing gas according to the measured values of the flowmeter 19 or the water quality meter 20. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a water treatment apparatus provided with a microbubble generator that generates ozone-containing gas from an ozone generator as microbubbles in treated water.

  Water treatment plants use the strong oxidizing power of ozone, measures against mold odor and coloring associated with deterioration of raw water quality, and carcinogens generated in the chlorine disinfection process (THMs; hereinafter referred to as THMs). For the purpose of reducing the precursors, ozone treatment is used. Ozone is characterized by the oxidative degradation and reduction of biological nitrogenous substances such as humic acid and fulvic acid that have THMs-producing ability, ammonia nitrogen and anionic surfactants that cause water quality deterioration, and chlorine resistance. It is effective to inactivate Cryptosporidium parvum, which is a pathogenic microorganism having sexual properties, and it is self-degraded and finally decomposed into oxygen.

  However, the construction cost when the water treatment plant introduces ozone treatment is expensive, and it is difficult to introduce ozone treatment at small and medium-sized water treatment plants from the viewpoint of cost effectiveness. Furthermore, since ozone is generated by applying a voltage to oxygen in the air or the oxygen gas itself, generation costs are required. For this reason, it is difficult to introduce ozone treatment in small and medium-sized water purification plants, and there are cases where a large amount of powdered activated carbon is injected to adsorb and remove odorous substances and persistent organic substances. A large amount of powdered activated carbon has a problem that the treatment cost increases and the amount of sludge increases, and there is a water purification plant where ozone treatment is an appropriate treatment method.

  Activated carbon adsorption treatment is used as an exhaust ozone treatment device for treating ozone that could not be dissolved in water. However, the carbon and ozone contained in the activated carbon undergo an oxidative decomposition reaction, gradually reducing the amount of activated carbon. Furthermore, ozone is dissolved in the water to be treated after the ozone treatment, and the organic matter and disinfection by-products that have been reduced in molecular weight by the ozone are adsorbed. Don't be.

  In order to reduce the power costs for generating ozone, it is necessary to reduce the amount of ozone injected. Therefore, it is effective to improve the dissolution efficiency of ozone, and there is a method in which the ozone gas to be introduced is injected as fine bubbles. In recent years, research on a microbubble-applied water treatment method, which is a collective term for microbubble utilization technologies, has been advanced. It is considered that water treatment with reduced gas consumption can be performed by promoting dissolution of ozone, oxygen, and the like.

  Examples of water treatment for refining ozone gas include, for example, Patent Literature 1 to Patent Literature 4, and on the treatment water introduction route, or on the route for pumping the treatment water held in the ozone tank, Some have a mechanism to perform gas mixing and pressure operation to make bubbles finer.

  As exemplified in Non-Patent Document 1 as a microbubble generation method, there are a swirling flow type, a static mixer type, an ejector type, a venturi type, a pressure dissolution type, an ultrafine hole, etc., which are specified on the tubular flow path. Each method is accompanied by a water supply device such as a pump. For this reason, the addition of pump power for boosting and driving the liquid is added to generate microbubbles.

Thus, when the gas consumption reduction by microbubble production | generation is aimed at, there exists a subject that pump power is added now.
JP 2007-21392A JP 2007-21393 A JP-A-9-290280 JP-A-9-276882 Koichi Terasaka "Microbubble generation method and its application to industrial equipment" Chemical Industry, Vol. 71, No. 3, pages 170-173 Hirofumi Taisei “Today's Challenges of Microbubble Technology” Chemical Industry Vol. 71, No. 3, pp. 154-159

  In the above-described ozone treatment facility using the conventional bubble refining technology, there is a problem that pump power is required for the bubble refining operation.

  In addition, when a mechanism for performing gas mixing or pressure operation is arranged on the path for pumping the water to be treated in the ozone tank, and the bubbles are made finer, depending on the bubble content of the water supply target, Operation may become difficult, and there is a problem that necessary ozone gas cannot be stably introduced into the ozone tank.

  Further, as exemplified in Non-Patent Document 2, the refined bubbles have a feature that the rising speed of the bubbles is slow. For this reason, in the refinement | miniaturization of the bubble aiming at the gas melt | dissolution in an ozone tank, the stirring effect accompanying the bubble introduction gas bubble accompanying the bubble refinement | miniaturization reduces remarkably. In Patent Documents 1 to 4, although it is functionally possible to use the pump water required for the bubble generation operation as a stirring force, the pump water supply amount is further increased in order to maintain the gas-liquid mixing operation in the entire area of the tank. There is a problem to do.

  As described above, the microbubble technology is expected to have the effect of reducing the ozone consumption by reducing the ozone gas, but there are problems in increasing the ozone treatment cost and performing the stable ozone treatment.

  The present invention has been made in order to solve the above-described problems. By applying a microbubble ozone generator having a rotating plate, a pump is not required for the bubble miniaturization operation, and the pump is immersed in an ozone tank. In addition, while suppressing the increase in the cost of ozone treatment due to the use of microbubbles due to the pumping power, while maintaining the ozone tank agitation effect associated with the decrease in the bubble rising speed in the microbubbles, the water supply operation for the bubble-containing water in the bubble refining operation is unnecessary. Thus, an object of the present invention is to provide a water treatment apparatus capable of stably supplying ozone microbubbles at a low cost because necessary ozone gas can be stably introduced.

  In order to achieve the above object, the present invention introduces an ozone tank that introduces water to be treated and performs ozone treatment, and one or a plurality of ozone tanks in the ozone tank, and introduces an ozone-containing gas generated from an ozone generator. And a microbubble generator for generating microbubbles in the water to be treated in the ozone tank, a flow meter provided on the introduction side of the ozone tank, for measuring the flow rate of the water to be treated, and a predetermined in the ozone tank One or a plurality of water quality meters provided at a location and measuring the water quality of the water to be treated; and a control device for performing the ozone treatment of the water to be treated based on the measured value of the flow meter or the water quality meter. The bubble generating device is disposed in the ozone tank and is formed in a hollow disk shape, a plurality of bubble injection holes formed at predetermined positions on at least the upper surface of the bubble injection unit, If you support the bubble injection part At least a rotating shaft that rotates by receiving the rotational force of the motor, and a gas supply pipe that introduces ozone generated from the ozone generator into the bubble injection unit, and gas containing ozone from the ozone generator Microbubbles of ozone-containing gas, which are guided to the bubble injection part through the supply pipe, and the bubbles coming out from the bubble injection hole formed in the bubble injection part are torn off by the shearing force generated by rotating the bubble injection part In the ozone tank, and the control device controls the rotational speed of the bubble injection unit in the microbubble generator according to the measurement value of the flow meter or one or more water quality meters, the ozone At least one of the flow control of the ozone containing gas supplied from a generator to a microbubble generator is performed.

  According to the present invention, the cost of ozone treatment in microbubble application by pump power is eliminated by applying a microbubble ozone generator having a rotating plate so that a pump is not necessary for bubble miniaturization operation. While suppressing the increase and maintaining the ozone tank agitation effect associated with the decrease in the bubble rising speed in the microbubbles, it is possible to stably introduce the necessary ozone gas by eliminating the need for the water supply operation in the bubble refinement operation. Therefore, ozone microbubbles can be stably supplied at a low cost.

<First Embodiment>
"overall structure"
FIG. 1 is a block diagram showing a first embodiment of a water treatment apparatus according to the present invention.

  The water treatment apparatus shown in the figure includes an ozone tank 1, an ozone generator 2 that generates ozone-containing gas supplied into the ozone tank 1, and ozone-treated water ozone-treated in the ozone tank 1 using activated carbon. An activated carbon treatment device 3 that performs adsorption treatment and an exhaust ozone gas decomposition device 4 that introduces and decomposes exhaust ozone gas 23 discharged from the ozone tank 1 are provided.

  The ozone tank 1 is composed of a first reaction tank 5, a second reaction tank 6, and an ozone retention tank 7, and the first reaction tank 5 and the second reaction tank 6 are partition walls 8, and the second reaction tank 6 and ozone. The residence tank 7 is partitioned by a partition wall 9.

  In particular, in this embodiment, two microbubble generators 10 and 11 are juxtaposed on the bottom surface of the first reaction tank 5. Similarly, two microbubble generators 12 and 13 are juxtaposed on the bottom surface of the second reaction tank 6. The detailed configuration of the microbubble generator will be described later with reference to FIGS.

  In addition, ozone flow rate adjusters 15 to 18 for adjusting the flow rate of the ozone-containing gas are provided in the path 14 for supplying the ozone-containing gas from the ozone generator 2 to the microbubble generators 10 to 13, respectively.

  Furthermore, a flow meter 19 for measuring the inflow rate of the water to be treated flowing into the ozone tank 1, a water quality meter 20 for measuring the quality of the ozone treated water in the vicinity of the ozone retention tank 7, the flow meter 19 and the water quality meter 20. And a control device 21 that controls the microbubble generators 10 to 13 and the ozone flow rate adjusters 15 to 18.

<Description of microbubble generator>
Next, a microbubble generator applied to the present invention will be described in detail with reference to FIGS.

  The microbubble generator shown in FIGS. 2 to 15 is an apparatus using a shearing method. This device generates bubbles by tearing bubbles coming out from the pores in the disk with the shearing force generated by rotating the disk. It can be generated with low pressure loss. By using this microbubble generator, it is possible to reduce the number of installed microbubble generators and to save power.

  FIG. 2 shows a first configuration example of the microbubble generator. The microbubble generator includes a bubble injection unit 53 that injects microbubbles 52 into a water tank 51, a gas supply pipe 54 that supplies ozone gas to the bubble injection unit 53, and the bubble injection unit 53 that rotates via a belt 55. A motor 56 to be driven, a pulley 57 attached to the rotating shaft of the motor 56, a rotating shaft 58 that rotatably supports the bubble injection portion 53, and a driving force from the motor 56 attached to the rotating shaft 58 is belted. And a pulley 59 for receiving the rotation shaft 55 and rotating the rotation shaft 58.

  As shown in FIG. 3, the bubble injection portion 53 is formed in a hollow disk shape, and a plurality of bubble injection holes 61 are formed on the upper surface 60. The bubble injection hole 61 is disposed so as to have a certain distance from the rotation shaft 58. That is, a region 62 where the bubble injection hole 61 is not provided is present near the center of the rotating shaft 58.

  In the microbubble generator configured as described above, when ozone gas is supplied from an ozone generator (not shown) through the gas supply pipe 54, the water in the water tank 51 filled with the water to be treated from the bubble injection unit 53. Bubbles are injected into. At this time, the rotational force of the motor 56 is transmitted to the rotary shaft 58 via the pulley 57 → the belt 55 → the pulley 59, and the disk-shaped bubble injection portion 53 rotates at a high speed. At that time, the bubbles injected into the water tank 51 from the bubble injection portion 53 are torn off by shearing by rotation before growing into large bubbles, and are forcibly separated from the bubble injection holes 61 to be diffused into the water as microbubbles 52. Will be.

  When bubbles are injected into the fluid from the bubble injection unit 53, the diameter of the bubbles changes due to the shearing force received from the surrounding fluid. That is, as the rotational speed increases and the peripheral speed at the bubble injection hole 61 increases, the shearing force increases, so the bubble diameter decreases. FIG. 4 shows the result of experimentally verifying this property using a small-scale test apparatus. As shown in FIG. 4, it can be seen that the average diameter of the generated bubbles decreases as the peripheral speed increases under the condition where the peripheral speed in the bubble injection hole 61 is 6 m / s or less. By utilizing this property, the diameter of the generated bubbles can be changed.

  Moreover, under the condition where the peripheral speed is 6 m / s or more, the diameter of the generated bubbles becomes a constant value of about 0.2 mm even if the peripheral speed changes. Since the peripheral velocity in the bubble injection hole 61 is represented by the product of the angular velocity of rotation of the bubble injection portion 53 and the distance between the rotary shaft 58 and the bubble injection hole 61, the angular velocity in the bubble injection hole 61 is 6 m / s or more. The average diameter of the bubbles generated from all the bubble injection holes 61 is about 0.2 mm, the distribution of the diameters of the bubbles generated from the bubble injection portion 53 is small, and it is possible to generate bubbles with uniform diameters.

  FIG. 4 shows the results of an experimental investigation of the relationship between the diameter of the bubble injection hole 61 and the average diameter of the generated bubbles. According to this result, the average diameter of the generated bubbles decreases as the diameter of the bubble injection hole 61 decreases under the condition where the angular velocity is 6 m / s, but under the condition where the angular speed is 6 m / s or more. The influence of the diameter of the bubble injection hole 61 on the average diameter of the generated bubbles is eliminated, and it becomes constant at about 0.2 mm. Due to this property, even if the bubble injection hole 61 is 1 mm which is large as the bubble injection hole 61 of the microbubble generator, it is possible to generate bubbles having a diameter of about 0.2 mm. When the bubble injection hole 61 is enlarged, the pressure loss in the bubble injection hole 61 can be reduced, and the power of the blower and compressor used for bubble injection can be reduced.

  FIG. 5 shows the relationship between the angular velocity of the bubble injection hole 61 and the average diameter of the generated bubbles when the gas flow rate is changed at four locations of the bubble injection holes 61 having a diameter of 1.0 mm.

  As can be understood from this relationship, it is shown that when the gas flow rate increases and reaches 1 liter / min, fine bubbles cannot be generated even if the rotational speed is increased. From this tendency, it can be seen that in order to generate fine bubbles, the gas flow rate needs to be equal to or less than the limit value. FIG. 6 shows the relationship between the angular velocity in the bubble injection hole 61 and the average diameter of the generated bubbles when the number of bubble injection holes 61 having a diameter of 1.0 mm is increased to eight and the gas flow rate is changed. It was confirmed that fine bubbles could be generated even at a flow rate of 2 liters / minute, in which fine bubbles could not be generated under the conditions of four locations under the conditions of eight bubble injection holes 61. From these results, it can be understood that the limit value of the air flow rate can be increased while the bubble diameter is kept small by increasing the number of the bubble injection holes 61. FIG. 7 shows the relationship between the pitch P (see FIG. 3) indicating the interval between adjacent bubble injection holes 61 and the average bubble diameter of the generated bubbles. From this relationship, it was found that the average bubble diameter of the generated bubbles is remarkably increased when the pitch P of the bubble injection holes 61 is 15 mm or less.

  FIG. 8 shows a second configuration example of the microbubble generator. In this example, the bubble injection portion 53 is formed in two circular plates 63 and 64 arranged to face each other with a predetermined gap, and a circumferential portion in the gap between the two circular plates 63 and 64. It is characterized by comprising a small diameter nozzle 65.

  In the microbubble generator configured as described above, the ozone-containing gas 66 is injected into the water tank 51 from the small diameter nozzle 65. When the disk having the small-diameter nozzle 65 in the circumferential portion is driven to rotate, the ozone-containing gas 66 is broken by the shearing force acting at this time to become microbubbles 52. Further, since all the bubble injection holes 61 are provided on the same circumference, almost uniform bubbles are generated.

  According to this example, bubbles are injected from the nozzles 65 having a small diameter arranged side by side on the same circumference, and the homogeneous microbubbles 52 can be generated by the shearing force acting at the time of injection.

  FIG. 9 shows a third configuration example of the microbubble generator. In this example, the side surface of the bubble injection portion 53 is formed of a porous body 67.

  In the microbubble generator configured as described above, the gas is supplied from the gas supply pipe 54 and released from the porous body 67 formed on the side surface of the disk, but the porous body 67 is rotated by the motor 56. Given. Although the porous body 67 is not homogeneous compared to the hole formed by machining in the disk, the porous body 67 can be produced with a minute hole diameter of several μm, and therefore generates the microbubbles 52. Therefore, it becomes more effective.

  FIG. 10 shows a fourth configuration example of the microbubble generator. In the fourth configuration example, the collision plate 68 is provided above the bubble injection portion 53.

  In the micro-generation apparatus configured as described above, the ozone-containing gas is supplied from the gas supply pipe 54 and is injected into the liquid from the bubble injection unit 53 that is rotated. At this time, the microbubbles 52 generated from the bubble injection unit 53 collide with the upper collision plate 68 rotating in synchronization with the bubble injection unit 53. When the microbubbles 52 generated by the bubble injecting portion 53 collide with the collision plate 68, a further minute bubble can be generated by applying a shearing force from the rotating collision plate 68.

  FIG. 11 shows a fifth configuration example of the microbubble generator. This configuration example is characterized in that a baffle plate 69 is disposed on the upper surface side of the bubble injection portion 53.

  In this configuration example, the gas supplied through the gas supply pipe 54 is injected into the water tank 51 from the bubble injection unit 53 that is rotationally driven by the motor 56, but at this time, it collides with the baffle plate 69. As a result, it is possible to prevent the microbubbles 52 from being collected at the center of the rotation axis.

  By preventing the microbubbles 52 from collecting at the center of the water tank by the baffle plate 69, the circulating flow in the water tank is generated uniformly, and the microbubbles 52 can be generated more efficiently.

  FIG. 12 shows a sixth configuration example. The gas supplied through the gas supply pipe 54 is rotated by the motor 56 via the pulley 59 and the microbubbles 52 are injected from the bubble injection unit 53 into the water tank 51. At this time, the gas bubbles collide with the baffle plate 69. . The baffle plate 69 is vibrated by the baffle plate vibration source 70, and the diameter of the bubbles is further reduced by contacting the baffle plate 69 that vibrates.

  In the sixth configuration example, the microbubbles 52 gather at the center by the rotational force and have the property of being combined, but the baffle plate 69 can prevent the microbubbles 52 from gathering at the center. Further, the microbubbles 52 can be efficiently generated by splitting the combined bubbles again.

  FIG. 13 shows a seventh configuration example.

  The feature of this configuration is that the bubble injection portion 53 is covered with the porous cover 71.

  The bubbles injected from the bubble injection unit 53 are reduced in diameter by rotation, and the reduced diameter bubbles pass through the porous cover 71 and are discharged into the water tank.

  Thus, by covering the bubble injection part 53 rotated by the porous cover 71, it is possible to prevent foreign matters from coming into contact with the rotating part.

  FIG. 14 shows an eighth configuration example.

  In this configuration example, a collision plate 72 is provided with a predetermined gap on the upper surface side of the bubble injection portion 53, and a plurality of columnar bubble crushing portions 73 are provided on the outer edge portion of the gap between the bubble injection portion 53 and the collision plate 72. It is characterized by having a book.

  In this case, the ozone-containing gas is supplied from the gas supply pipe 54 and injected into the liquid from the bubble injection unit 53 that has been rotated. However, the microbubbles 52 generated from the bubble injection unit 53 are separated from the bubble injection unit 53. It collides with the upper colliding plate 72 rotating in synchronization and flows toward the outer edge of the gap. And after colliding with the bubble crushing part 73 provided in the outer edge part, it discharge | releases in the water tank 51. FIG.

  According to this configuration example, the microbubbles 52 generated from the bubble injecting unit 53 collide with the bubble crushing unit 73 and split, so that even more microbubbles 52 can be generated.

  FIG. 15 shows a ninth configuration example.

  This configuration example is characterized in that a wing 74 is provided in a region 62 (see FIG. 3) where the bubble injection hole 61 is not provided in the bubble injection portion 53.

  Along with the rotation of the bubble injection part 53, a flow from the center to the outside is induced on the surface of the bubble injection part 53 by the blades 74. This flow facilitates the detachment of the bubbles from the bubble injection hole 61.

  As described above, the flow induced by the blades 74 promotes the detachment of the bubbles from the bubble injection hole 61, so that finer bubbles can be generated.

  In the above microbubble generating device, the driving force of the motor 56 is indirectly transmitted to the rotating shaft 58 via the belt 55 and pulleys 57 and 59. The rotating shaft 58 is used as the rotating shaft of the motor 56. Alternatively, a direct drive system that directly rotates and drives may be used. In the first to third embodiments according to the present invention, description will be made using a direct-drive type microbubble generator.

<< Operation of First Embodiment >>
Next, the operation of this embodiment provided with the fine bubble generating apparatus as described above will be described.

  The inflow flow rate of the water to be treated after the coagulation sedimentation process, which is a process before the ozone treatment, is measured by the flow meter 19, and the measurement value signal is transmitted to the control device 21. In addition, the flowmeter 19 should just use the measuring device which performs a well-known water flow rate measurement, Although a format is not ask | required in particular, the apparatus which can be measured in the applied water quality and flow range is used.

  The ozone generator 2 is preferably an ozone generator that generates an ozone-containing gas in a gaseous state and that ozonizes the oxygen-containing gas under a high voltage by, for example, a discharge technique.

The ozone-containing gas generated in the ozone generator 2 is supplied to the microbubble generators 10 to 13 arranged in the first reaction tank 5 and the second reaction tank 6, respectively. At that time, the flow rate is adjusted by ozone flow rate adjusters 15 to 18 that adjust the flow rate of the supplied ozone-containing gas, and then supplied to the microbubble generators 10 to 13. Here, as the ozone flow rate regulators 15 to 18, any known gas flow rate regulator that can measure and adjust the concentration and flow rate of ozone gas to be introduced may be used, and the type is not particularly limited. A separate ozone flow rate regulator is installed for the microbubble generator.

  The ozone-containing gas supplied via the ozone flow rate controllers 15 to 18 is supplied to the microbubble generators 10 to 13. Although the configuration of the microbubble generators 10 to 13 is as described above, the generated bubble diameter is desirably 200 μm or less. Each bubble injection part 53 of each microbubble generator 10-13 refines | purifies the ozone containing gas discharged | emitted from a perforated plate with the water flow produced | generated to the outer peripheral side from the center of a rotating hollow disc. The bubble injection portion 53 is not uniform with respect to the water surface of the ozone tank 1 so that the bubble refining action does not become uneven due to the deviation of the discharge amount of the ozone-containing gas discharged from the bubble injection portion 53 that is a porous plate due to the difference in water head pressure. Is arranged horizontally with the porous surface as the upper surface and the ozone tank water surface to be installed.

  In addition, by arranging a plurality of the microbubble generators in the ozone tank 1, the supply of the required amount of ozone when the required amount of ozone is increased, and at the same time, the hollow disk (bubble injection part 53) constituting the microbubble generator is provided. Stir mixing of the ozone-containing gas in the ozone tank can be maintained by the water flow generated by the rotating action.

  In addition, when arranging a plurality of microbubble generators in the ozone tank, the disk surface of the bubble injection part 53 in the microbubble generator in the same tank is positioned at the same water level, so that each microbubble generator The amount of ozone-containing gas discharged can be made uniform.

  The water quality of the ozone treated water 22 after the ozone treatment in the first reaction tank 5 and the second reaction tank 6 is measured by a water quality meter 20. The water quality meter 20 may be, for example, a device that measures the dissolved ozone concentration or a known technique that measures the dissolved organic matter concentration, and is not particularly limited, but it is desirable to use a measuring device that can be applied according to the quality of the treated water. A plurality of different water quality measuring instruments may be used. Stable ozone treatment can be performed by supplying the ozone-containing gas without excess or deficiency according to the measurement value of the water quality meter 20. The supply of ozone gas referred to here constitutes the microbubble generator that adjusts the supply amount of the ozone flow rate adjusters 15 to 18 according to the required ozone amount and contributes to the refinement of the ozone-containing gas. This is to adjust the rotational speed of the hollow disk (bubble injection part 53). When the ozone supply amount is increased, the controller 21 adjusts the rotational speed to increase and the ozone supply amount to be reduced.

  The ozone-treated water 22 is introduced into the activated carbon treatment apparatus 3 filled with activated carbon. Here, the activated carbon treatment apparatus 3 adsorbs and removes ozone dissolved in the ozone-treated water 22 and remaining organic substances after oxidative decomposition, such as disinfection by-products such as bromic acid and aldehydes. A known technique such as a fixed bed reaction tower packed with granular activated carbon may be used.

  Exhaust ozone gas 23 discharged from the first reaction tank 5 and the second reaction tank 6 is introduced into the exhaust ozone gas decomposition apparatus 4. Here, the exhaust ozone gas decomposition apparatus 4 may use a known technique for decomposing the ozone component contained in the exhaust ozone gas 23 and reducing the ozone concentration in the gas discharged out of the system. What is necessary is just to select gas residence time, decomposition agent filling amount, kind, etc. from the assumed ozone concentration and ozone flow rate.

"effect"
According to the present embodiment, unlike the conventional bubble micronization (microbubble) technology, the microbubble generators 10 to 13 of the embodiment of the present invention refine ozone-containing gas without pumping water operation, It can be supplied to the tank 1. For this reason, the disk rotational power included in the microbubble generators 10 to 13 immersed in the ozone tank 1 against the increase in the energy consumption of the ozone treatment accompanying the pressure loss generated during the pump water supply operation in the prior art. However, in this water flow generation operation, no energy loss corresponding to the pressure loss generated by the conventional technique occurs.

  Moreover, the stirring and mixing in the ozone tank 1 can be maintained by the water flow accompanying the disk rotation of the bubble injection unit 53 of the microbubble generators 10 to 13 immersed in the ozone tank 1, and the ozone-containing gas to be introduced can be maintained. Mixing of fine bubbles and water to be treated can be achieved simultaneously with finer bubbles.

  Since there is no pump circulation operation of gas-liquid two-phase fluid containing microbubbles in water treatment using conventional ozone microbubbles, problems such as fluctuations in pumping water capacity with increased bubble content do not occur, so it is stable The ozone-containing gas can be refined and supplied. Furthermore, by eliminating the influence of the water head pressure on the bubble refinement portions in the microbubble generators 10 to 13, the microbubble generators are made non-uniform in the ability to refine the bubbles and placed in the same ozone tank. It is possible to suppress the non-uniformity of the bubble refining ability between the generated microbubble generators and to stably supply the refined ozone-containing gas.

  According to the water treatment apparatus described above, it is possible to reduce power consumption and stably supply ozone in a water treatment apparatus that uses ozone gas as fine bubbles.

<Second Embodiment>
Next, 2nd Embodiment of the water treatment apparatus using the microbubble based on this invention is described using FIG. In addition, the same code | symbol is attached | subjected to the structure same as 1st Embodiment, and the overlapping description is abbreviate | omitted.

"Constitution"
In the second embodiment, the bubble removal tank 25 provided between the ozone retention tank 7 outlet, which is the last stage of the ozone tank 1 for reacting the ozone-containing gas and the water to be treated, and the activated carbon treatment apparatus 3, An air diffuser 26 that introduces a gas having a larger bubble diameter than the fine bubbles supplied to the microbubble generators 10 to 13 into the bubble removing tank 25, and an air diffuser gas 27 to the air diffuser 26. And a flow rate regulator 28 for adjusting the amount of gas introduced. Other symbols are the same as those in FIG.

<Action>
According to the present embodiment, the fine ozone-containing gas bubbles supplied to the first reaction tank 5 and the second reaction tank 6 have a small bubble diameter, and are therefore in the order of millimeters introduced by a normal air diffuser. It is known that the residence time in water is longer than that of bubbles. For this reason, ozone treated water 22 containing ozone microbubbles can be introduced into the activated carbon treatment apparatus 3 from the outlet of the ozone retention tank 7 which is the last stage of the ozone tank 1 for reacting the ozone-containing gas and the water to be treated. There is sex. At this time, the load of the ozonolysis reaction with respect to the activated carbon filled in the activated carbon treatment apparatus 3 may increase.

  In the present embodiment, fine ozone microbubbles are obtained by performing gas diffusion with a larger bubble diameter than the fine ozone-containing gas bubbles supplied to the first reaction tank 5 and the second reaction tank 6 by the air diffuser 26. And the gas bubbles at the upper part of the bubble removal tank 25 by promoting the disappearance of the ozone microbubbles and the bubble rising speed after the coalescence by the coalescence action with the aeration gas having a large bubble diameter. it can.

  Here, the kind of the diffused gas discharged from the diffuser 26 is not particularly limited, but air, oxygen, nitrogen, ozone-containing gas from the ozone generator 2 or the like may be selected, but the ozone consumption is excessive. In order to prevent the increase, it is desirable to select a gas source other than the ozone generator 2. The form of the air diffuser 26 is not particularly limited, but a gas supply device having a gas bubble diameter larger than that of ozone microbubbles supplied to the first reaction tank 5 and the second reaction tank 6 may be selected.

"effect"
According to this embodiment, by reducing the amount of ozone microbubbles introduced into the activated carbon treatment device 3, an increase in the load of the ozone decomposition reaction on the activated carbon charged in the activated carbon treatment device 3 can be suppressed. The increase in the cost of the filled activated carbon of the activated carbon treatment device 3 can be suppressed.

<Third Embodiment>
Next, a third embodiment of the water treatment apparatus using microbubbles according to the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the structure same as 1st Embodiment, and the overlapping description is abbreviate | omitted.

"Constitution"
In the third embodiment, the first reaction tank 5 and the second reaction tank 6 are provided with a first reaction tank water quality meter 31 and a second reaction tank water quality meter 32, respectively. It is the same.

<Action>
The first reaction tank water quality meter 31 and the second reaction tank water quality meter 32 shown in FIG. 17 measure the water quality in the first reaction tank 5 and the second reaction tank 6, respectively. For example, the dissolved ozone concentration is measured. What is necessary is just to use the well-known technique which measures a dissolved organic substance density | concentration, and it does not specifically limit. However, it is desirable to use a measuring instrument applicable according to the quality of the treated water, and a plurality of different water quality measuring instruments may be used.

  According to the measured values of the first reaction tank water quality meter 31 and the second reaction tank water quality meter 32, the first reaction tank 5 and the second reaction tank 6 are supplied with an ozone-containing gas without excess or deficiency, so that stable ozone treatment can be achieved. it can. The supply of ozone gas here refers to adjusting the supply amount of the ozone flow rate adjusters 15 to 18 according to the required amount of ozone, or contributing to the refinement of the ozone-containing gas. Is adjusted by the control device 21 that controls to increase the rotation speed and decrease the ozone supply amount when the ozone supply amount is increased. To do.

  When increasing the amount of ozone supplied in the water in the first reaction tank 5, first, the number of rotations of the hollow disks (bubble injection part 53) of the microbubble generators 10 and 11 within the set allowable range is increased, and the bubble fineness is increased. Promote conversion. As a result of this operation, when the ozone supply amount satisfies the set value, the rotational speed of the hollow disk (bubble injection part 53) of the microbubble generators 10 and 11 is decreased stepwise. In this control operation, priority is given to the rotation speed of the hollow disk (bubble injection part 53) of one of the microbubble generators 10 and 11 according to the installation position of the first reaction tank water quality meter 31 in the first reaction tank 5. May be increased.

  If the amount of ozone supply in the water is insufficient only by increasing the number of rotations of the microbubble generators 10 and 11, then the ozone flow rate of the ozone flow rate controllers 15 and 16 is increased. If the ozone supply amount satisfies the set value as a result of this operation, the ozone flow rate of the ozone flow rate adjusters 15 and 16 is reduced stepwise, and then the rotational speed of the microbubble generators 10 and 11 is reduced.

  When the amount of ozone supply in water in the first reaction tank 5 is increased, the amount of ozone supply preferentially from the upstream microbubble generator 12 out of the microbubble generators 12 and 13 arranged in the second reaction tank 6. Increase. The increase control of the ozone supply amount is controlled in the order of increasing the rotation speed of the microbubble generator → the flow rate of the ozone gas supplied to the microbubble generator as in the case of increasing the ozone supply amount in water in the first reaction tank 5 described above.

  Similarly to increasing the amount of ozone supply in water in the first reaction tank 5 when increasing the amount of ozone supply in water in the second reaction tank 6, the hollow disk (bubble injection part 53) of the microbubble generators 12 and 13. When increasing the ozone flow rate of the ozone flow rate regulators 17 and 18 and decreasing the ozone supply amount, the ozone flow rate reductions of the ozone flow rate regulators 17 and 18 and the microbubble generators 12 and 13 are reduced. The number of rotations of the hollow disk (bubble injection part 53) is reduced.

  In addition, when the flow rate of the water to be treated in the flow meter 19 is increased or decreased, the same control as described above is used as the supply ozone amount increase control when the flow rate is increased, and as the ozone amount supply control when the flow rate of the treated water is decreased. I do.

"effect"
By arranging the water quality meters 31 and 32 in the first reaction tank 5 and the second reaction tank 6 constituting the ozone tank 1, it is possible to grasp the present required ozone amount and maintain the required ozone amount without excess or deficiency. Can do. In addition to the water quality change of the water to be treated, the ozone supply amount according to the change in the treatment flow rate can be maintained. In the operation of increasing the ozone supply amount, the amount of ozone gas consumed can be reduced by preferentially increasing the number of revolutions of the hollow disk (bubble injection portion 53) of the microbubble generators 10-13. Moreover, in the ozone supply amount reduction operation, by reducing the ozone gas flow rate preferentially, the ozone gas consumption can be reduced and the stirring and mixing action in the ozone tank can be maintained. The water quality response at 31, 32 can also be maintained.

  According to this embodiment, reduction of ozone consumption accompanying the application of ozone microbubbles can be achieved, and stable ozone treatment can be performed.

The block diagram which shows 1st Embodiment of the water treatment apparatus which concerns on this invention. The block diagram which shows an example of the microbubble generator applied to this invention. The block diagram which shows an example of the microbubble generator applied to this invention. Explanatory drawing which shows the characteristic of a microbubble generator. Explanatory drawing which shows the characteristic of a microbubble generator. Explanatory drawing which shows the characteristic of a microbubble generator. Explanatory drawing which shows the characteristic of a microbubble generator. The block diagram which shows the 2nd structural example of the microbubble generator applied to this invention. The block diagram which shows the 3rd structural example of the microbubble generator applied to this invention. The block diagram which shows the 4th structural example of the microbubble generator applied to this invention. The block diagram which shows the 5th structural example of the microbubble generator applied to this invention. The block diagram which shows the 6th structural example of the microbubble generator applied to this invention. The block diagram which shows the 7th structural example of the microbubble generator applied to this invention. The block diagram which shows the 8th structural example of the microbubble generator applied to this invention. The block diagram which shows the 9th structural example of the microbubble generator applied to this invention. The block diagram which shows 1st Embodiment of the water treatment apparatus which concerns on this invention. The block diagram which shows 1st Embodiment of the water treatment apparatus which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Ozone tank 2 ... Ozone generator 3 ... Activated carbon processing apparatus 4 ... Exhaust ozone gas decomposition apparatus 5 ... 1st reaction tank 6 ... 2nd reaction tank 7 ... Ozone residence tank 8, 9 ... Septum 10-13 ... Microbubble generator DESCRIPTION OF SYMBOLS 14 ... Path | route 15-18 ... Ozone flow controller 19 ... Flow meter 20 ... Water quality meter 21 ... Control apparatus 22 ... Ozone treated water 23 ... Exhaust ozone gas 25 ... Bubble removal tank 26 ... Air diffuser 27 ... Gas for diffuser 28 ... Flow controller 31 ... First reactor water quality meter 32 ... Second reactor water quality meter

Claims (6)

An ozone tank that introduces water to be treated and performs ozone treatment;
One or a plurality of microbubble generators that are provided in the ozone tank and introduce the ozone-containing gas generated from the ozone generator to generate microbubbles in the water to be treated in the ozone tank;
A flow meter that is provided on the introduction side of the ozone tank and measures the flow rate of the water to be treated;
One or more provided at a predetermined location in the ozone tank, and a water quality meter for measuring the quality of water to be treated;
A controller that performs ozone treatment of the water to be treated based on the measurement value of the flow meter or the water quality meter,
The microbubble generator is
A bubble injection portion disposed in the ozone tank and formed in a hollow disc shape, a plurality of bubble injection holes drilled at a predetermined position on at least the upper surface of the bubble injection portion, and the bubble injection portion as a shaft An ozone-containing gas from the ozone generator, comprising at least a rotating shaft that supports and rotates in response to the rotational force of the motor, and a gas supply pipe that introduces ozone generated from the ozone generator into the bubble injection unit. Is introduced to the bubble injection part through the gas supply pipe, the bubbles coming out from the bubble injection hole formed in the bubble injection part are torn off by the shearing force generated by rotating the bubble injection part, and the ozone-containing gas It generates micro bubbles in the ozone tank,
The control device includes:
According to the measurement value of the flow meter or one or more water quality meters, the rotational speed control of the bubble injection unit in the microbubble generator, the flow rate of the ozone-containing gas supplied from the ozone generator to the microbubble generator Execute at least one of the controls,
A water treatment apparatus characterized by that. The water treatment apparatus according to claim 1,
The ozone tank is composed of a plurality of reaction tanks,
The microbubble generator is provided in each reaction tank,
An ozone flow rate regulator for adjusting the flow rate of the ozone-containing gas is provided in a path for supplying the ozone-containing gas from the ozone generator to each microbubble generator,
The control device controls the rotation speed of the bubble injection unit in the microbubble generator provided in each reaction tank, and adjusts the flow rate of ozone-containing gas supplied from the ozone generator to each microbubble generator. By controlling the instrument,
A water treatment apparatus characterized by that. The water treatment device according to claim 1 or 2,
A water treatment apparatus characterized in that the upper surface position of the hollow disk-shaped bubble injection part of a plurality of microbubble generators installed in an ozone tank is arranged at the same water level position of the ozone tank. The water treatment apparatus according to any one of claims 1 to 3,
A bubble diameter larger than the ozone-containing gas introduced between the ozone tank and the activated carbon treatment apparatus that adsorbs ozone treated water discharged from the ozone tank with activated carbon, and introduced into the ozone tank from the microbubble generator. A bubble removal tank that introduces a gas having a microbubble to remove the gas,
A water treatment apparatus further comprising: In the water treatment apparatus according to any one of claims 1 to 4,
The control unit executes a rotation speed variable control that increases or decreases the rotation speed control of the bubble injection unit in the microbubble generator in a stepwise manner according to the measurement value of the flow meter or one or a plurality of water quality meters. ,
A water treatment apparatus characterized by that. The water treatment apparatus according to any one of claims 1 to 5,
The control device includes:
The ozone consumption is calculated by a flow meter, a water quality meter, and an exhaust ozone concentration meter that measures the concentration of exhaust ozone, and the ozone supply amount control for the increase / decrease of the ozone demand with respect to the ozone consumption is performed. Controlled by the number of rotations of the hollow disk-shaped bubble injection portion constituting
A water treatment apparatus characterized by that.

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