JP4759553B2 - Gas-liquid dissolution tank in microbubble generator - Google Patents

Description

  The present invention is used for a fine bubble generating apparatus in which a gas is pressurized and dissolved in a liquid flowing in a pipeline and then fine bubbles are ejected into the liquid in the liquid tank to disperse and contain the fine bubbles. The present invention relates to a gas-liquid dissolution tank in which a gas is dissolved under pressure in a liquid.

  Conventionally, after the liquid in the liquid tank is circulated outside and the gas is pressurized and dissolved in the liquid, the fine bubbles are jetted into the liquid in the liquid tank again by reducing the pressure with the fine bubble generating nozzle in the liquid tank. There are known microbubble generators that disperse microbubbles into a liquid. The fine bubble generating device includes a flow path through which a liquid flows, an air suction port that mixes air with the liquid flowing through the flow path to form a gas-liquid mixed liquid, and a pump that pressurizes the gas-liquid mixed liquid and flows it into the flow path And a gas-liquid dissolution tank for supplying the gas-liquid mixed liquid to dissolve the gas in the liquid to make the gas-liquid dissolved liquid, and generating the fine bubbles by reducing the pressure of the obtained gas-liquid dissolved liquid, It is comprised from the fine bubble generation nozzle for making the liquid in a tank contain a fine bubble. Here, in order for the liquid containing fine bubbles to exert its effect, it is necessary to generate and contain a large amount of fine bubbles. This is related to the gas-liquid dissolution tank and the fine bubble generating nozzle. In many cases, the amount of gas dissolved in the gas-liquid dissolving liquid is important, that is, the gas dissolving efficiency in the gas-liquid dissolving tank is important.

  As the gas-liquid dissolving means, a high-pressure pump is used as a pump for pressure-feeding the gas-liquid mixed liquid to dissolve the gas in the liquid under high pressure, and the undissolved surplus gas is removed inside the gas-liquid dissolving tank. Separate the gas-liquid dissolved liquid to the fine bubble generation nozzle side, or use a low-pressure pump to pump the gas-liquid mixed liquid under pressure to dissolve the gas in the liquid under low pressure. There is a means for dissolving the gas in the liquid and feeding it to the fine bubble generating nozzle side by spraying the liquid surface in the liquid dissolution tank from above the gas-liquid dissolution tank.

  By the way, in the above conventional gas-liquid dissolving means, the means for dissolving the gas in the liquid by increasing the pressure has to use a high-pressure pump for the pump, so that the pump itself becomes large. In addition, since it is used under high pressure, it is necessary to manufacture the gas-liquid dissolution tank with a high-strength material. For this reason, there is a problem that the microbubble generator is large in size and high in cost.

  In order to increase the dissolution efficiency under low pressure, the low-pressure pump is used to dissolve the gas in the liquid by injecting the gas-liquid mixed liquid from above the gas-liquid dissolution tank onto the liquid surface in the gas-liquid dissolution tank. Needs to increase the contact area of the gas in the gas-liquid mixed liquid to the liquid. For this purpose, the gas-liquid mixed liquid must be sprayed to a region below the liquid level in the gas-liquid dissolution tank. For this purpose, the height dimension of the gas-liquid dissolution tank itself is required. Therefore, the gas-liquid dissolution tank itself becomes large, and as a result, it becomes large as a fine bubble generator. Therefore, in order to install these devices, there is a problem that the location is restricted.

  On the other hand, as a conventional technique, a gas-liquid dissolution tank has been proposed for generating a gas-liquid dissolution liquid by radially expanding and blowing liquid from a spray nozzle installed above the liquid in a bubbling tank (for example, a patent) Reference 1). However, this cannot necessarily be universalized as an apparatus that efficiently generates a gas-liquid solution without taking up space.

Japanese Patent Laid-Open No. 2005-95878

  The present invention has been generalized by solving the problems in the above-described conventional high-pressure pumps and those using low-pressure pumps, and at low cost while reducing the size of the gas-liquid dissolution tank. Another object of the present invention is to provide a gas-liquid dissolution tank that can improve the dissolution efficiency of a gas into a liquid even at a low pressure.

According to the first aspect of the present invention for solving the above-described problems, in the first aspect of the present invention, the tank main body 11 and the tank main body 11 having the suction port 14 outside the tank main body 11 and jetting upward in the tank main body 11 are provided. and an injection nozzle 16 having a mouth 16a, formed from the interior of the discharge port 19 which projects outside the lower liquid level 17, the injection port 16a and an upper portion inside of the collision portion 20 of the oppositely disposed tank body 11 of the tank body 11 In the gas-liquid dissolution tank 8 of the gas-liquid generator A, the area of the injection port 16 a of the injection nozzle 16 is smaller than the area of the suction port 14, and the collision part 20 inside the tank body 11 is connected to the upper end of the tank body 11. The gas-liquid dissolution tank 8 in the gas-liquid generator A is characterized in that it is formed from the lower part of a cap 12 made of a separate part .

In the invention of claim 2, the collision part 20 formed from the lower part of the cap 12 is formed so that the area thereof is smaller than the area of the liquid surface 17 in the tank body 11. It is a gas-liquid dissolution tank 8 in the gas-liquid generator A of the means.

According to a third aspect of the present invention, the collision portion 20 is formed from a lower end surface having a downward concavo-convex shape which has a height which is low at the central portion and is gradually increased toward the periphery. Or it is the gas-liquid dissolution tank 8 in the gas-liquid generator A of the means of Claim 2.

According to a fourth aspect of the present invention, the tank body 11 has a discharge port 19 projecting to the outside formed in the bottom 11a of the tank main body 11 . It is a gas-liquid dissolution tank 8 in the gas-liquid generator A.

Since the present invention is the above-described means, in the invention according to claim 1, since the area of the injection port is made smaller than the area of the suction port, it is possible to increase the flow velocity of the liquid ejected from the injection port. Thus, the local high pressure portion in the collision portion can be further increased. Thus, it increases the dissolution efficiency of the gas into the liquid.

In the invention according to claim 2, in addition to the effect of the invention according to claim 1, since the area of the collision part is smaller than the area of the liquid surface in the tank body, the collision part above the inside of the tank body. And the liquid dispersed at 360 degrees collides with the side wall surface of the tank body, which is the periphery of the collision part formed smaller than the liquid surface area in the tank body, so that the gas is dissolved in the liquid. dissolution efficiency is you more improvement.

In the invention according to claim 3, in addition to the effect of the invention according to claim 2, the upper upper collision part of the tank body has a lower height at the center part, and a downward unevenness that inclines as it gradually increases toward the periphery. Since it is formed from the lower end surface of the shape, the area where the liquid ejected from the ejection port collides is increased, and the liquid ejected from the ejection port is collected without being dispersed after the collision, and is efficiently localized. Therefore, it becomes possible to make a local high-pressure part efficiently. From this, it further improves dissolution efficiency of the gas into the liquid.

In the invention according to claim 4, in addition to the effect of the invention according to claim 3, the discharge port 19 that protrudes to the outside of the tank body 11 is formed in the bottom portion 11 a of the tank body 11. It becomes possible to reduce the size. When large bubbles of undissolved gas are discharged from the gas-liquid dissolution tank, it is difficult to generate fine bubbles, so it is necessary to provide a discharge port in a conventional gas-liquid dissolution tank where the undissolved large bubbles do not reach. Therefore, the gas-liquid dissolution tank itself becomes large, but in the present invention, since the liquid ejected from the injection port is rebounded by the collision portion above the inside of the tank main body, the liquid level in the tank main body Since the surface area for landing is increased and rebounding, the injection pressure to the liquid surface is suppressed, so undissolved large bubbles are reduced, and as a result, undissolved large bubbles are generated in the tank body. it is suppressed to flow to the lower, discharge ports 19 be formed on the bottom 11a of the tank body 11 Ru can reduce the liquid level below the depth at the gas-liquid dissolving tank.

  As described above, it is possible to obtain a gas-liquid dissolution tank capable of improving the efficiency of dissolving a gas into a liquid even at a low pressure while reducing the size of the gas-liquid dissolution tank. Furthermore, the use of the gas-liquid dissolution tank of the present invention makes it possible to miniaturize the pump of the microbubble generator, so that the microbubble generator itself can be reduced in size and weight, the restrictions on the installation location can be reduced, and the cost can be reduced. This is an excellent effect that has never been achieved.

  The best mode for carrying out the present invention will be described with reference to the drawings. The present invention is not limited to this embodiment.

In the accompanying drawings, FIG. 1 is a schematic circuit diagram of a fine bubble generator A having a gas-liquid dissolution tank 8 of the present invention. FIG. 2 is a schematic cross-sectional view of the gas-liquid dissolution tank 8 which is the basis of the present invention. FIG. 3 is a schematic longitudinal sectional view for explaining the structure of the gas-liquid dissolution tank 8 in the first embodiment of the present invention. 4A and 4B are schematic views for explaining the structure of the cap according to the first embodiment of the present invention. FIG. 4A is a side view showing the section, and FIG. 4B is a bottom view. FIG. 5 is a schematic cross-sectional view illustrating the structure of the gas-liquid dissolution tank 8 in the second embodiment of the present invention. 6A and 6B are schematic views for explaining the structure of a cap according to the second embodiment of the present invention. FIG. 6A is a side view showing a cross section, and FIG. 6B is a bottom view (schematic cross-sectional view). FIG. 7 is a schematic cross-sectional view illustrating the structure of the gas-liquid dissolution tank 8 in the third embodiment of the present invention. FIGS. 8A and 8B are schematic views for explaining the structure of a cap according to the third embodiment of the present invention. FIG. 8A is a side view showing the cross section, and FIG. 8B is a bottom view. FIG. 9 is a schematic cross-sectional view illustrating the structure of the gas-liquid dissolution tank 8 in the fourth embodiment of the present invention. FIG. 10 is a schematic cross-sectional view illustrating the structure of the gas-liquid dissolution tank 8 having an air vent valve in the fifth embodiment of the present invention.

  An example embodied as an embodiment of the fine bubble generating nozzle 3 of the present invention will be described based on an example applied as the fine bubble generating device A for the liquid tank 1 shown in FIG. As shown in FIG. 1, a fine bubble generating nozzle 3 is installed in the liquid in the liquid tank 1. Similarly, a pump 5 is connected to a suction port 2 installed in the liquid via a suction pipe 4 outside the liquid tank 1. A gas introduction pipe 7 having a gas suction port 6 for sucking gas in an atmosphere such as air is disposed in the suction pipe 4 on the suction port side of the pump 5. A gas-liquid dissolution tank 8 for dissolving the gas sucked from the gas suction port 6 into a liquid is disposed on the downstream side of the pump 5. The pump 5 and the gas-liquid dissolution tank 8 communicate with each other by an inflow conduit 9. The liquid is circulated to the fine bubble generating nozzle 3 installed in the liquid in the liquid tank 1 by the discharge pipe 10 on the downstream side of the gas-liquid dissolution tank 8 to form the fine bubble generating device A.

  Here, when the power of the pump 5 is turned on, the liquid in the liquid tank 1 is sucked into the pump 5 from the suction port 2 through the suction pipe 4. At that time, the gas installed in the middle of the suction pipe 4 Since the gas is sucked from the gas suction port 6 of the introduction pipe 7, the liquid sucked into the pump 5 is in a gas-liquid mixed state. At this time, since the gas introduction pipe 7 is composed of an ejector mechanism, it is naturally aspirated without requiring any special power. Furthermore, the liquid in the gas-liquid mixed state is pressurized by the pump 5 and sent to the gas-liquid dissolution tank 8 through the inflow conduit 9. The liquid in the gas-liquid mixed state is pressurized and dissolved in the gas-liquid dissolution tank 8 to become a gas-liquid dissolved state, and is sent to the fine bubble generating nozzle 3 through the discharge pipe 10. By the way, in order to generate many fine bubbles in the fine bubble generating nozzle 3, the amount of gas dissolved in the gas-liquid dissolving liquid is involved. That is, the dissolution efficiency of gas in the gas-liquid dissolution tank 8 is important. In order to improve the dissolution efficiency of the gas in the liquid, it is necessary to create a high-pressure state in the gas-liquid dissolution tank 8 or to increase the contact area of the gas with the liquid.

The gas-liquid dissolution tank 8 which is the basis of the present invention shown in FIG. 2 is formed by integrating the ceiling portion 11 b of the tank body 11 with the tank body 11. A suction port 14 connected to the inflow conduit 9 is provided outside the gas-liquid dissolution tank 8, and an ejection nozzle 16 extending from the suction port 14 is piped into the gas-liquid dissolution tank 8 from the side wall of the gas-liquid dissolution tank 8. Yes. The jet outlet 16a of the jet nozzle 16 in the gas-liquid dissolution tank 8 is directed upward. In this case, the injection port 16 a is disposed at a position higher than the liquid level in the gas-liquid dissolution tank 8. By the way, the area of the basic injection port 16a is smaller than the area of the suction port 14. The liquid ejected from the ejection port 16a collides with the collision part 20 on the lower surface of the cap 12, spreads around, and is ejected downward.

In the form of the gas-liquid dissolution tank 8 as the basis, the gas-liquid mixed liquid sent from the pump 5 shown in FIG. 1 is sucked into the jet nozzle 16 extending into the tank body 11 from the suction port 14 shown in FIG. . The ejection nozzle 16 in the tank body 11 has a tapered hole 15 having a narrowed tip shape, and is ejected vigorously through the taper hole 15 from the ejection port 16a upward in the tank body 11. The liquid ejected from the ejection port 16a falls on the lower liquid surface 17 in a state where it bounces off and scatters at the collision part 20 provided in the ceiling part 11b, and reaches the water. Since the inside of the tank main body 11 is in a pressurized state due to liquid feeding by the pump 5 shown in FIG. 1, the gas in the gas-liquid mixed liquid is filled in the upper part of the tank main body 11. For this reason, gas will melt | dissolve in a liquid in the process which falls from said ejection and lands. In addition, by causing the gas-liquid mixed liquid to collide with the collision portion 20, a local high-pressure portion is easily created. In this high-pressure portion, the gas is easily dissolved in the liquid, so that the efficiency of dissolving the gas in the liquid is improved. In order to further increase the dissolution efficiency, it is necessary to increase the contact area of the gas with the liquid. Therefore, as shown in FIG. 2, the inner surface shape of the collision portion 20 is uniformly expanded to the liquid surface where the scattering state is slightly squeezed by making the center side a slightly dome shape. As described above, since the area when the liquid surface 17 lands on the liquid surface 17 is evenly expanded, the structure in which the contact area of the gas with the liquid is increased, and also in this respect, the dissolution efficiency of the gas in the liquid is improved. ing.

Therefore, the gas-liquid dissolution tank 8 of the first embodiment of the invention according to claim 1 shown in FIG. 3 is composed of a tank main body 11 and a cap 12 made of a separate member screw-fitted to the tank main body 11. The lower surface of the cap 12 forms a ceiling portion 11 b that is the upper end of the tank body 12. In this case, the cap 12 made of a separate body, in the following second to fourth embodiment forms of the invention according to claim 2, is identical to that of the embodiment of the invention according to any claim 1. The cap 12 is screwed into the tank body 11 and sealed with an O-ring 13. A suction port 14 connected to the inflow conduit 9 is provided outside the gas-liquid dissolution tank 8, and an ejection nozzle 16 extending from the suction port 14 is piped from the side wall of the gas-liquid dissolution tank 8 into the dissolution tank. The jet outlet 16a of the jet nozzle 16 in the dissolution tank 8 is directed upward. In this case, the injection port 16 a is disposed at a position higher than the liquid level in the gas-liquid dissolution tank 8. By the way, as an embodiment of the invention according to claim 1 , the area of the injection port 16 a is formed smaller than the area of the suction port 14. The liquid ejected from the ejection port 16a collides with the collision part 20 on the lower surface of the cap 12, spreads around, and is ejected downward.

In the first embodiment, the gas-liquid mixed liquid sent from the pump 5 shown in FIG. 1 is sucked into the jet nozzle 16 extending into the tank body 11 from the suction port 14 shown in FIG. The ejection nozzle 16 in the tank body 11 has a tapered hole 15 having a narrowed tip shape, and is ejected vigorously through the taper hole 15 from the ejection port 16a upward in the tank body 11. The liquid ejected from the ejection port 16a falls on the lower liquid surface 17 in a state where it bounces off and scatters on the lower surface of the cap 12, which is the collision portion 20, and lands. Since the inside of the tank main body 11 is in a pressurized state due to liquid feeding by the pump 5 shown in FIG. 1, the gas in the gas-liquid mixed liquid is filled in the upper part of the tank main body 11. For this reason, gas will melt | dissolve in a liquid in the process which falls from said ejection and lands. In addition, a local high-pressure portion is easily created by causing the gas-liquid mixed liquid to collide with the lower surface of the cap 12. In this high-pressure portion, the gas is easily dissolved in the liquid, so that the efficiency of dissolving the gas in the liquid is improved. In order to further increase the dissolution efficiency, it is necessary to increase the contact area of the gas with the liquid. Therefore, as shown in FIG. 4A, the inner surface shape of the cap 12 is evenly spread to the liquid surface to be landed by narrowing the scattering state by making it a dome shape. As described above, since the area when the liquid surface 17 lands on the liquid surface 17 is evenly expanded, the structure in which the contact area of the gas with the liquid is increased, and also in this respect, the dissolution efficiency of the gas in the liquid is improved. ing.

  Here, when undissolved large bubbles are sent from the discharge port 19 formed in the bottom 11 a of the tank body 11 to the fine bubble generating nozzle 3 shown in FIG. 1, fine bubbles are generated at the fine bubble generating nozzle 3. It becomes difficult to do. Furthermore, the noise generated when the gas-liquid dissolved liquid passes through the discharge port 19 is increased. Therefore, in the conventional apparatus, it is necessary to provide the discharge port 19 in a deep place so that undissolved large bubbles do not reach and be discharged. Therefore, it has been necessary to make the tank body 11 large in size with a large depth to the bottom 11a. On the other hand, the tank body 11 of the present invention has a structure in which the liquid ejected from the ejection port 16a rebounds on the lower surface of the cap 12, and the liquid surface 17 when landing on the liquid surface 17 in the tank body 11 is used. Since the injection pressure for landing on the liquid surface 17 is suppressed by expanding the area as described above, large undissolved bubbles can be prevented from flowing to the bottom portion 11 a of the lower portion of the tank body 11. As a result, since the depth below the liquid surface 17 of the tank body 11 of the gas-liquid dissolution tank 8 can be reduced and shallow, the gas-liquid dissolution tank 8 can be reduced in size. The gas-liquid dissolving liquid generated in the gas-liquid dissolving tank 8 is fed from the discharge port 19 to the fine bubble generating nozzle 3 shown in FIG. Is generated.

The gas-liquid dissolution tank 8 of the second embodiment of the present invention shown in FIG. 5 is composed of a tank body 11 and a cap 12 as shown in FIG. 3, and the cap 12 is threadedly engaged with the tank body 11. And is sealed by an O-ring 13. In this case, as an embodiment of the invention according to claim 1 , the area of the injection port 16 a of the injection nozzle 16 can be made smaller than the area of the suction port 14. Furthermore, as an embodiment of the invention according to claim 2 , the area in the collision part 20 of the liquid ejected from the jet outlet 16 a in the tank body 11 of the gas-liquid dissolution tank 8 is the surface of the liquid surface 17 in the tank body 11. It can be made smaller than the area. In the second embodiment, the injection port 16 a of the injection nozzle 16 is disposed higher than the liquid level 17 in the tank body 11. Further, as shown in FIG. 6, the inner surface of the cap 12 having the upper portion in the tank body 11 as the collision portion 20 has a plurality of annular ribs 18 having a downward concavo-convex shape downward as the second embodiment of the present invention. Is formed. The plurality of downwardly formed annular ribs 18 have a low height at the center, and gradually increase toward the periphery and extend downward to form an inclined uneven bottom surface.

  In the gas-liquid dissolution tank 8 of the third embodiment, the gas-liquid mixed liquid sent from the pump 5 shown in FIG. 1 is sucked from the suction port 14 of the tank body 11 as in the second embodiment, The liquid is ejected vigorously upward from the injection port 16a through the tip-shaped tapered hole 15 into the tank body 11. The liquid ejected from the ejection port 16 a rebounds on the inner surface of the cap 12 that is the collision portion 20 and scatters on the lower liquid surface 17. Since the tank body 11 is in a pressurized state and the gas is filled in the upper part of the tank body 11, the gas is dissolved in the liquid by the process of falling and landing from the jet. Here, a local high pressure part can be made by colliding with the inner surface of the cap 12. In this high-pressure part, since the gas is easily dissolved in the liquid, the efficiency of dissolving the gas in the liquid is improved.

  Furthermore, in the third embodiment, there are a plurality of annular ribs 18 formed downward on the inner surface of the cap 12, and the height of each of the ribs 18 is inclined so that the central portion becomes lower and the height gradually increases toward the periphery. Therefore, a collision occurs between the jetted gas-liquid mixed liquid and each rib 18 from the central portion to the peripheral edge, and it is possible to make a local high-pressure portion in each rib 18 and gas. The dissolution efficiency in the liquid is further improved. Further, by forming the plurality of downward annular ribs 18 on the inner surface of the cap 12, the collision area is controlled and the size of the liquid surface 17 is increased, and the scattering state can be expanded. Thus, since the area when landing on the liquid surface 17 in the tank body 11 is uniformly expanded, the contact area between the gas and the liquid is increased. Also in this respect, the dissolution efficiency of the gas in the liquid is improved.

  Here, if undissolved large bubbles are sent from the discharge port 19 formed in the bottom 11a of the tank body 11 to the fine bubble generating nozzle 3 shown in FIG. 1, the fine bubble generating nozzle 3 hardly generates the fine bubbles. In addition, the noise is even greater. Therefore, in such a case, the discharge port 19 must be provided where large undissolved bubbles do not reach the bottom 11a of the tank body 11, so that the tank body 11 itself of the gas-liquid dissolution tank 8 becomes large. . The tank main body 11 of the gas-liquid dissolution tank 8 of the third embodiment has a structure in which the liquid ejected from the ejection port 16 a rebounds from the inner surface of the cap 12, and further reaches the liquid surface 17 in the gas-liquid dissolution tank 8. The area when the liquid is increased to the size of the liquid surface 17 by the annular rib 18 composed of a plurality of concave and convex surfaces, and the injection pressure to the liquid surface 17 is suppressed. 11 is suppressed from flowing to the bottom 11a, the depth from the liquid surface 17 in the tank body 11 can be reduced. As a result, the gas-liquid dissolution tank 8 can be further reduced in size. The obtained gas-liquid dissolved liquid is fed from the discharge port 19 to the fine bubble generating nozzle 3 in the liquid in the liquid tank 1 shown in FIG.

  The gas-liquid dissolution tank 8 of the third embodiment shown in FIG. 7 is composed of a tank body 11 and a cap 12 in the same manner as shown in FIG. The cap 12 is screwed into the tank body 11 and sealed with an O-ring 13. The area of the collision part 20 of the liquid ejected from the ejection port 16a of the ejection nozzle 16 in the tank main body 11 is narrowed by the arc-shaped rib 18 as shown in FIG. The area of the surface 17 is smaller. Further, the area of the injection port 16 a is smaller than the area of the suction port 14, and the injection port 16 a is disposed higher than the liquid level in the tank body 11. That is, as can be seen in FIGS. 8A and 8B, the inner surface of the cap 12 having the upper portion in the tank body 11 as the collision portion 20 has an arc-shaped rib 18 composed of a plurality of downward arcs. Are formed symmetrically. The plurality of downward-facing arc-shaped ribs 18 are provided on the lower surface of the concave and convex portions which are inclined by lowering the central portion and increasing the height toward the periphery.

The gas-liquid mixed liquid sent from the pump 5 shown in FIG. 1 is sucked from the suction port 14 of the tank body 11 shown in FIG. 7, passes through the tapered hole 15 of the spray nozzle 16 in the tank body 11, and then reaches the tank from the spray port 16 a. It is ejected upward in the main body 11. The liquid ejected from the ejection port 16a bounces off at the collision part 20 on the inner surface of the cap 12 and lands on the liquid surface 17 in the tank body 11 in a scattered state. Since the tank body 11 is in a pressurized state and the gas is filled in the upper part of the gas-liquid dissolution tank 8, the gas is dissolved in the liquid by the process of falling and landing from the jet. Here, it becomes possible to make a local high pressure part by making it collide with the collision part 20 of the inner surface of the cap 12, In this high pressure part, the melt | dissolution to the gas liquid mixed with the gas mixed liquid is performed. Since it becomes easy, the dissolution efficiency in the gas liquid is improved. Further, in the gas-liquid dissolution tank 8 of the third embodiment, the arc-shaped ribs 18 formed on the inner surface of the cap 12 are inclined such that the height of each rib 18 is lower at the center and is gradually increased toward the periphery. Since it is provided on the concavo-convex surface, a collision occurs between the jetted gas-liquid mixed liquid and each rib 18 from the central part to the peripheral edge, and a local high-pressure portion is formed in each rib 18 in a single layer. The dissolution efficiency in the liquid is improved. Further, by forming the arc-shaped rib shape 18 on the inner surface of the cap 12, the collision area is enlarged in the chord direction of the arc, and the scattering state can be increased. Furthermore, since the area when landing on the liquid surface 17 is also increased, the contact area of the gas with the liquid is increased. Also in this respect, the dissolution efficiency of the gas in the liquid is improved.

Here, if undissolved large bubbles are sent from the discharge port 19 formed in the bottom 11a of the tank body 11 to the fine bubble generating nozzle 3 shown in FIG. 1, the fine bubble generating nozzle 3 hardly generates the fine bubbles. Moreover, the noise at the discharge port 19 is also increased. Therefore, in the case of such a conventional apparatus, since the discharge port 19 of the tank body 11 must be provided where the undissolved large bubbles do not reach the bottom portion 11a, the tank body 11 becomes large. On the other hand, the tank body 11 of the first embodiment has a structure in which the liquid ejected from the ejection port 16a rebounds from the inner surface of the cap 12, and further reaches the liquid surface 17 in the tank body 11. When the area is large, the spray pressure on the liquid surface 17 is suppressed. Accordingly, it is possible to suppress undissolved large bubbles from flowing to the bottom 11a of the tank body 11, and to reduce the depth below the liquid surface 17 in the tank body 11. Thereby, the gas-liquid dissolution tank 8 can be reduced in size. The generated gas-liquid dissolved liquid is fed from the discharge port 18 to the fine bubble generating nozzle 3 shown in FIG. 1 and generates fine bubbles from the fine bubble generating nozzle 3 in the liquid in the liquid tank 1.

The gas-liquid dissolution tank 8 of the fourth embodiment, which is an example according to the invention of claim 4 of the present invention shown in FIG. 9 , is composed of a tank body 11 and a cap 12 as shown in FIG. ing. Unlike the first embodiment of FIG. 3, in the tank main body 11 shown in FIG. 9, the injection nozzles 16 from the suction port 14 to the injection outlet 16a are linear and are arranged vertically below the tank main body 11. It is set. This also has the same effect as that of the gas-liquid dissolution tank 8 of the first embodiment of the present invention in terms of the conversion effect from the gas-liquid mixed liquid to the gas-liquid molten liquid.

The gas-liquid dissolution tank 8 of the fifth embodiment of the present invention shown in FIG. 10 is configured by providing an air vent valve 21 in the gas-liquid dissolution tank 8 constituted by the tank body 11 and the cap 12 shown in FIG. ing. The air vent valve 21 is provided to discharge the surplus gas in the gas-liquid dissolution tank 8 to the outside and keep the height of the liquid surface 17 in the gas-liquid dissolution tank constant. 1 is taken in from the gas suction port 6 of FIG. 1 and sent from the gas introduction pipe 7 to the gas-liquid dissolution tank 8 by the pump 5 and injected from the injection nozzle 16, and the surplus gas in the gas-liquid dissolution tank 8 increases. When 17 is pushed down and lowered, the conversion effect from the gas-liquid mixed liquid to the gas-liquid dissolved liquid is lowered. In the gas-liquid dissolution tanks of the first to fifth embodiments of the present invention, the air vent valve 21 is not provided, but when the gas suction amount from the gas suction port 6 is constant, the liquid level 17 in the dissolution tank 8 is fixed. There is no displacement. However, when the amount of gas sucked from the gas suction port 6 changes due to the usage method of the fine bubble generating device, the displacement of the liquid surface 17 is provided by providing the vent valve 21 in the dissolution tank 8 as in the present embodiment. Is suppressed, and a stable conversion effect from a gas-liquid mixed liquid to a gas-liquid dissolved liquid can be obtained. This was the same as the gas-liquid dissolution tank of the first embodiment of the present invention in terms of the conversion effect from the gas-liquid mixed liquid to the gas-liquid dissolved liquid.

The conversion experiment from the gas-liquid mixed liquid to the gas-liquid dissolved liquid was conducted using the gas-liquid dissolving tank 8 of the present invention in the first to fifth embodiments. It was found that it has the effect of converting liquid-mixed liquid to gas-liquid dissolved liquid. The conversion effect of the gas-liquid dissolved liquid is the best in the second and fifth embodiments, then in the fourth embodiment, and then in the result of the first embodiment. The conversion effect of the third embodiment was substantially the same as the conversion efficiency of the first embodiment. In the present invention, the gas-liquid dissolution tank 8 has the structure of the above-described embodiment, so that the tank body 11 can be reduced in size, and the dissolution efficiency of the gas into the liquid can be improved at low cost even at low pressure. A possible gas-liquid dissolution tank 8 is obtained.

1 is a schematic circuit diagram of a fine bubble generator according to an embodiment of the present invention. It is typical sectional drawing explaining the structure of the gas-liquid dissolution tank used as the foundation of this invention. It is typical sectional drawing explaining the structure of the gas-liquid dissolution tank in the 1st Embodiment of this invention. It is a schematic diagram explaining the structure of the cap in the 1st Embodiment of this invention, (a) is a side view shown by a cross section, (b) is a bottom view. It is typical sectional drawing explaining the structure of the gas-liquid dissolution tank in the 2nd Embodiment of this invention. It is a schematic diagram explaining the structure of the cap in the 2nd Embodiment of this invention, (a) is a side view shown by a cross section, (b) is a bottom view. It is a schematic diagram explaining the structure of the gas-liquid dissolution tank in the 3rd Embodiment of this invention, (a) is a side view shown in a cross section, (b) is a bottom view. It is typical sectional drawing explaining the structure of the cap in the 3rd Embodiment of this invention. It is typical sectional drawing explaining the structure of the gas-liquid dissolution tank in the 4th Embodiment of this invention. It is typical sectional drawing explaining the structure of the gas-liquid dissolution tank which has an air vent valve in the 5th Embodiment of this invention.

DESCRIPTION OF SYMBOLS 1 Liquid tank 2 Suction port 3 Fine bubble generation nozzle 4 Suction line 5 Pump 6 Gas suction port 7 Gas introduction pipe 8 Gas-liquid dissolution tank 9 Inflow line 10 Discharge line 11 Tank body 11a Bottom part 11b Ceiling part 12 Cap 13 O Ring 14 Suction port 15 Tapered hole 16 Injection nozzle 16a Injection port 17 Liquid surface 18 Rib 19 Discharge port 20 Colliding part 21 Air vent valve A Fine bubble generator

Claims (4)

A tank main body (11), an injection nozzle (16) having a suction port (14) outside the tank main body (11) and having an injection port (16a) directed upward in the tank main body (11); A discharge port (19) projecting outside below the liquid level (17) inside the tank main body (11), and a collision portion (20 above the inside of the tank main body (11) arranged to face the injection port (16a). In the gas-liquid dissolution tank (8) of the gas-liquid generator (A) formed from the above, the area of the injection port (16a) of the injection nozzle (16) is smaller than the area of the suction port (14), and the tank body (11 The gas-liquid generator (A) is characterized in that the upper collision part (20) is formed at the upper end of the tank body (11) from the lower part of a cap (12) made of a separate part. Gas-liquid dissolution tank in (8). The collision part (20) formed from the lower part of the cap (12) is formed so that the area thereof is smaller than the area of the liquid surface (17) in the tank body (11). The gas-liquid dissolution tank (8) in the gas-liquid generator (A) described in 1. The collision part (20) is formed from the lower end surface of the downward concavo-convex shape which has a height which is low at the central part and is gradually increased toward the periphery, and is inclined . Gas-liquid dissolution tank (8) in the gas-liquid generator (A). The tank body (11) has a discharge port (19) projecting to the outside formed in the bottom (11a) of the tank body (11). The gas-liquid dissolution tank (8) in the gas-liquid generator (A).

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