JP2013039497A - Gas dissolving apparatus and microbubble generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain a contact area of gas and liquid constant in a gas dissolving apparatus.SOLUTION: The gas dissolving apparatus 3 has first to fifth horizontal flow passages 321 to 325 in order from an upper side toward a lower side, and a damming part 32a is provided in the first horizontal flow passage 321 to the fourth horizontal flow passage 324. Mixed fluid of gas and liquid flows in the first horizontal flow passage 321 from a mixing nozzle 31 and liquid 72 is stored by the damming part 32a. The liquid 72 flowing over the damming part 32a flows down to the horizontal flow passage at a lower side. The liquid 72 flows while coming in contact with the gas, and consequently a pressurized liquid 71 where the gas is dissolved in the liquid 72 can be obtained. Though a cross-section of the horizontal flow passage is circular, height of a liquid surface of the liquid 72 is maintained constant by the damming part 32a and the contact area of the gas and the liquid 72 is also maintained constant. As a result, even when production amount of the pressurized liquid 71 is changed, the pressurized liquid where desired amount of gas per unit volume is dissolved can be easily obtained.

Description

  The present invention relates to a gas dissolving apparatus that pressurizes and dissolves gas into a liquid, and a fine bubble generating apparatus using the same.

  In recent years, attention has been paid to various functions of pressurized water in which air is pressurized and dissolved in water, and various utilization methods of water containing fine bubbles have been studied using this pressurized water. As an apparatus for producing such pressurized water, for example, there is one disclosed in Patent Document 1. In the gas-liquid pressurizing and mixing apparatus of Patent Document 1, a pipeline having a gradient that repeats slowing and steepening is provided, and a pressurized gas-liquid mixed flow is injected into this pipeline. As a result, efficient gas dissolution (including gas-liquid reaction; the same applies hereinafter) is realized. In addition, a technique for detecting an emergency of pressure by providing an intermediate throttle in the middle of a pipe and measuring the pressure state of a flow path before and after the intermediate throttle is disclosed.

  In the gas-liquid dissolution and mixing apparatus of Patent Document 2, a mixed fluid flowing through a pipe passes through a redistributor having a venturi pipe, and is then ejected from a nozzle portion provided with a plurality of nozzle holes on an end surface. In the redistributor, liquid and air bubbles gathered at the top of the conduit are accelerated at the throat of the venturi. After the liquid and bubbles are mixed in the duct of the nozzle portion, the bubbles are ejected from the plurality of nozzle holes in a state where the bubbles are distributed in the liquid. Since the nozzle hole is smaller than the duct, the liquid passing through the nozzle hole is accelerated and the static pressure is lowered. For this reason, the gas melt | dissolved in the liquid precipitates as a microbubble.

JP-A-6-210147 JP-A-6-63371

  By the way, in the production of pressurized water in which a desired amount of air per unit volume is dissolved in water, it is necessary to keep the contact area between air and water in the apparatus constant in order to ensure the production amount as designed. However, the required production volume is not always constant, and the required production volume differs for each apparatus. As a result, the design becomes complicated and it is not easy to reduce the manufacturing cost of the apparatus.

  In particular, in the fields of food, medicine, semiconductors and the like, a high level of cleanliness is required, and therefore, the use of circular piping is required. However, when such a pipe is used as it is, the contact area between the gas and the liquid largely fluctuates due to the fluctuation of the production amount. Therefore, the range in which the production amount can be changed is limited.

  The present invention has been made in view of the above problems, and an object of the present invention is to maintain a constant contact area between a gas and a liquid in a gas dissolving apparatus that pressurizes and dissolves a gas into a liquid.

  The invention according to claim 1 is a gas dissolving device for pressurizing and dissolving a gas into a liquid, wherein the liquid flows under the gas while the liquid is in contact with the gas under a pressurized environment, A damming portion provided at a lower portion in the first flow path for storing the liquid in the first flow path by preventing the flow of the liquid, and positioned below the first flow path, A second flow path through which the liquid flowing over the stop portion flows in a pressurized environment; a lower portion of a space in which the liquid in the first flow path is stored by the damming portion; and a damming portion. And a communication channel that communicates with the downstream space and guides part of the liquid stored in the first channel to the downstream space.

  Invention of Claim 2 is a gas dissolving apparatus of Claim 1, Comprising: The said damming part is a site | part which is fixed to the lower part of the said 1st flow path, and blocks the said lower part, The said communication flow A path is a through-hole penetrating the dam portion along the first flow path.

  A third aspect of the present invention is the gas dissolving apparatus according to the first aspect, wherein the communication flow path is a micro flow path that separately connects the first flow path and the second flow path.

  Invention of Claim 4 is the gas dissolving apparatus in any one of Claim 1 thru | or 3, Comprising: The said damming part goes to the said 2nd flow path in the said 1st flow path. It is provided at the immediately preceding position.

  The invention according to claim 5 is a gas dissolving device for pressurizing and dissolving a gas into a liquid, wherein the liquid flows under the gas while the liquid is in contact with the gas under a pressurized environment, A second channel that is located below the first channel and in which the liquid flowing from the first channel flows in a pressurized environment; a lower part in the first channel; and the second channel And a damming portion for storing the liquid in the first flow path by blocking the flow of the liquid, and the liquid flows into the second flow path beyond the damming portion. .

  The invention according to claim 6 is a gas dissolving device for pressurizing and dissolving a gas in a liquid, wherein the liquid flows under the gas while the liquid is in contact with the gas under a pressurized environment, A damming portion provided at a lower portion in the first flow path for storing the liquid in the first flow path by preventing the flow of the liquid, and positioned below the first flow path, The second flow path in which the liquid flowing over the stop portion flows in a pressurized environment and the state of the dam portion are changed between a state in which the flow of the liquid is blocked and a state in which the flow is not blocked. And a damming switching unit.

  A seventh aspect of the present invention is the gas dissolving device according to the sixth aspect, wherein the damming portion is a portion that is disposed in a lower portion of the first flow path and closes the lower portion, and the dam The stop switching part is a mechanism for rotating or lifting the dam part.

  The invention according to claim 8 is the gas dissolving device according to any one of claims 1 to 7, wherein the cross section of the inner side surface of the first flow path is a plane perpendicular to the extending direction of the first flow path. Is circular.

  A ninth aspect of the present invention is the gas dissolving apparatus according to any one of the first to eighth aspects, wherein the liquid is in contact with the gas in a pressurized environment in the second flow path. The flow direction of the liquid in the first flow path and the flow direction of the liquid in the second flow path are opposite to each other, and the gas dissolving device is disposed in a lower portion in the second flow path. And a further damming portion for storing the liquid in the second flow path by blocking the flow of the liquid.

  A tenth aspect of the present invention is the gas dissolving device according to any one of the first to ninth aspects, wherein the third flow path is located above the first flow path, the gas and the liquid. And a mixing nozzle that is jetted toward the third flow path, and the mixed fluid after being jetted from the mixing nozzle in the third flow path is under a pressurized environment, The liquid flows in the direction opposite to the flow direction of the liquid in the first flow path and flows into the first flow path.

  An eleventh aspect of the present invention is a micro-bubble generating device, wherein the gas dissolving device according to any one of the first to tenth aspects is provided on the liquid delivery path from the gas dissolving device, and the gas A throttling portion that maintains the pressure in the dissolving device, and passes through the throttling portion and is depressurized to generate fine bubbles in the liquid.

  The invention according to claim 12 is the fine bubble generating device according to claim 11, wherein a connection pipe connecting the gas dissolving device and the throttle portion, and a connection pipe provided in the connection pipe An adjustment valve that adjusts the pressure of the liquid, a pressure sensor that measures the pressure in the gas dissolving device, and a valve control unit that controls the adjustment valve based on an output from the pressure sensor.

  In the present invention, the contact area between the gas and the liquid can be maintained constant.

It is sectional drawing of a microbubble production | generation apparatus. It is an expanded sectional view of a mixing nozzle. It is sectional drawing of a dissolution channel part. It is a figure which shows a dam part. It is a figure which shows the relationship between a liquid level height and a gas-liquid contact area increase rate. It is an expanded sectional view of a fine bubble production nozzle. It is a figure which shows the other example of a dam part. It is a figure which shows other arrangement | positioning of a regulating valve. It is a figure which shows the other example of a dissolution flow path part. It is a figure which shows the further another example of a dissolution flow path part. It is a figure which shows the further another example of a dam part. It is a figure which shows the further another example of a dam part. It is a figure which shows the further another example of a dam part.

  FIG. 1 is a cross-sectional view showing a fine bubble generating apparatus 1 according to an embodiment of the present invention. The fine bubble generating device 1 includes a fine bubble generating nozzle 2, a gas dissolving device 3, and a connection pipe 4. The connection pipe 4 connects the fine bubble generating nozzle 2 and the gas dissolving device 3. The gas dissolving device 3 generates a pressurized liquid 71 in which a gas is dissolved under pressure, and supplies the pressurized liquid 71 to the fine bubble generating nozzle 2 that is a throttle portion via the connection pipe 4. The fine bubble generating nozzle 2 generates the gas fine bubbles in the target liquid 92 by ejecting the pressurized liquid 71 into the target liquid 92 in the water tank 91. In the fine bubble generating apparatus 1 according to the present embodiment, air bubbles having a diameter of less than 1 μm are ejected by ejecting a pressurized liquid 71 obtained by pressurizing and dissolving air in water into a target liquid 92 that is water. (So-called nanobubbles) are generated in the target liquid 92. In FIG. 1, in order to facilitate understanding of the drawing, a parallel oblique line is given to the fluid such as the target liquid 92 by a broken line (the same applies to the following similar drawings).

  The gas dissolving device 3 includes a mixing nozzle 31 and a dissolving flow path portion 32. In the gas dissolving device 3, the liquid (water in this embodiment) pumped to the mixing nozzle 31 by a pump (not shown) and the gas (air in this embodiment) sucked from the outside are mixed nozzles. 31 is mixed and ejected into the dissolution channel portion 32. The inside of the dissolution flow path portion 32 is pressurized and has a pressure higher than the atmosphere (hereinafter referred to as “pressurized environment”) (for example, a state higher than the atmospheric pressure by 50 kPa or more). While the mixed fluid 72 in which the jetted liquid and the gas are mixed flows in the dissolving flow path section 32 in a pressurized environment, the gas is pressurized and dissolved in the liquid to generate the pressurized liquid 71. .

  FIG. 2 is an enlarged cross-sectional view of the mixing nozzle 31. The mixing nozzle 31 includes a liquid inlet 311 into which the liquid pumped by the above-mentioned pump flows in, a gas inlet 319 into which gas flows in, a liquid flowing in from the liquid inlet 311, and a gas flowing in from the gas inlet 319. A mixed fluid ejection port 312 is provided for ejecting the mixed fluid 72 (see FIG. 1). The liquid inlet 311, the gas inlet 319, and the mixed fluid outlet 312 are each substantially circular.

  The flow path cross section of the nozzle flow path 310 from the liquid inlet 311 to the mixed fluid outlet 312 and the flow path cross section of the gas flow path 3191 from the gas inlet 319 to the nozzle flow path 310 are also substantially circular. The channel cross section means a cross section perpendicular to the central axis of the flow path such as the nozzle flow path 310 and the gas flow path 3191, that is, a cross section perpendicular to the flow of fluid flowing through the flow path. In the following description, the area of the channel cross section is referred to as “channel area”. The nozzle flow path 310 is a Venturi tube having a flow path area that becomes smaller in the middle of the flow path.

  The mixing nozzle 31 includes an introduction part 313, a first taper part 314, a throat part 315, a gas mixing part 316, a second taper part 317, and the like, which are sequentially arranged from the liquid inlet 311 toward the mixed fluid outlet 312. A derivation unit 318 is provided. The mixing nozzle 31 also includes a gas supply unit 3192 in which a gas flow path 3191 is provided.

  In the introduction part 313, the flow path area is substantially constant at each position in the direction of the central axis J1 of the nozzle flow path 310. In the first taper portion 314, the flow path area gradually decreases in the liquid flow direction (that is, toward the downstream side). In the throat 315, the flow path area is substantially constant. The channel area of the throat 315 is the smallest in the nozzle channel 310. In the nozzle channel 310, even if the channel area slightly changes in the throat 315, the entire portion having the smallest channel area is regarded as the throat 315. In the gas mixing unit 316, the flow channel area is substantially constant and is slightly larger than the flow channel area of the throat 315. In the second taper portion 317, the flow path area gradually increases toward the downstream side. In the derivation unit 318, the flow path area is substantially constant. The channel area of the gas channel 3191 is also substantially constant, and the gas channel 3191 is connected to the gas mixing unit 316 of the nozzle channel 310.

  In the mixing nozzle 31, the liquid that has flowed into the nozzle channel 310 from the liquid inlet 311 is accelerated by the throat portion 315 and the static pressure is lowered, and the pressure in the nozzle channel 310 is reduced in the throat portion 315 and the gas mixing portion 316. Becomes lower than atmospheric pressure. Thereby, gas is attracted | sucked from the gas inflow port 319, passes the gas flow path 3191, flows in into the gas mixing part 316, is mixed with the liquid, and the mixed fluid 72 (refer FIG. 1) is produced | generated. The mixed fluid 72 is decelerated at the second tapered portion 317 and the outlet portion 318 to increase the static pressure, and is ejected into the dissolution channel portion 32 via the mixed fluid ejection port 312.

  As shown in FIG. 1, the dissolution flow path section 32 includes a first horizontal flow path 321, a second horizontal flow path 322, a third horizontal flow path 323, and a fourth horizontal flow arranged in order from the upper side to the lower side. A path 324 and a fifth horizontal channel 325 are provided. In the following description, when the first horizontal flow path 321, the second horizontal flow path 322, the third horizontal flow path 323, the fourth horizontal flow path 324, and the fifth horizontal flow path 325 are collectively indicated, “horizontal flow path 321”. ~ 325 ". FIG. 3 is a view showing a longitudinal section of the horizontal flow paths 321 to 325 at the position of the arrow AA in FIG. Note that the “flow channel” in the present embodiment is a “flow channel forming unit” that accurately forms a space of the flow channel. The horizontal flow paths 321 to 325 are pipe lines extending in the horizontal direction, and the cross section perpendicular to the longitudinal direction of the horizontal flow paths 321 to 325 is circular. As shown in FIG. 1, the horizontal flow paths 321 to 325 are connected in series by a connection flow path 320 curved in an angle shape. The inner surfaces of the horizontal flow path and the connection flow path 320 are mirror-finished, for example.

  The mixing nozzle 31 is attached to the upstream end of the first horizontal flow path 321 (that is, the left end in FIG. 1), and the mixed fluid 72 after being ejected from the mixing nozzle 31 is It flows toward the right side in FIG. 1 under a pressurized environment. In the present embodiment, the mixed fluid 72 from the mixing nozzle 31 is ejected above the liquid level of the mixed fluid 72 in the first horizontal flow path 321 and directly collides with the liquid level.

  In the gas dissolving device 3, a part or the whole of the mixed fluid ejection port 312 of the mixing nozzle 31 may be positioned below the liquid level of the mixed fluid 72 in the first horizontal flow path 321. As a result, the mixed fluid 72 immediately after being ejected from the mixing nozzle 31 directly collides with the mixed fluid 72 flowing in the first horizontal flow channel 321 in the first horizontal flow channel 321 as described above.

  A damming portion 32 a is provided at the lower portion of the downstream end of the first horizontal flow path 321, and the damming portion 32 a prevents the flow of the mixed fluid 72 in the first horizontal flow path 321, thereby mixing. The fluid 72 is stored so as to stay. As shown in FIGS. 1 and 3, the mixed fluid 72 overflows over the blocking portion 32 a, falls in the connection flow path 320, and flows into the end portion of the second horizontal flow path 322. In the following description, the fluid flowing under the first to fifth horizontal flow paths 321 to 325 is not necessarily in a gas-liquid mixed state. Hereinafter, the fluid flowing in the lower part of these horizontal flow paths is simply referred to as “liquid 72”.

  In the second horizontal flow path 322, the liquid 72 flows from the right side to the left side in FIG. Also in the second horizontal flow path 322, a damming portion 32 a is provided at the lower part of the downstream end, and the damming portion 32 a prevents the liquid 72 from flowing in the second horizontal flow path 321. 72 is stored so as to stay. The liquid 72 overflows beyond the blocking portion 32 a, falls in the connection channel 320, and flows into the end portion of the third horizontal channel 322.

  Similarly, in the third horizontal flow path 323 and the fourth horizontal flow path 324, the damming portion 32a is provided, and the liquid 72 is stored. As described above, the blocking portion 32a is a portion that is fixed to the lower portion of the horizontal flow path and closes the lower portion. At the ends of the third and fourth horizontal flow paths 323 and 324, the liquid 72 falls toward the next horizontal flow path. In the third horizontal flow path 323, the liquid 72 flows from the left side to the right side in FIG. 1 under a pressurized environment, and in the fourth horizontal flow path 324, the liquid 72 flows from the right side to the left side in the pressurized environment. Flowing. In the first horizontal flow path 321 to the fourth horizontal flow path 324, the liquid 72 flows below the gas while in contact with the gas.

  Unlike the first to fourth horizontal flow paths 321 to 324, the fifth horizontal flow path 325 is not provided with the damming portion 32a. There is no gas layer in the fifth horizontal flow path 325, and in the liquid that fills the fifth horizontal flow path 325, there are slight bubbles near the upper surface of the fifth horizontal flow path 325. It has become. In the fifth horizontal flow path 325, the liquid 72 flowing in from the fourth horizontal flow path 324 flows from the left side to the right side in FIG. The fifth horizontal channel 325 is longer than the other horizontal channels 321 to 324.

  In the gas dissolving device 3, the horizontal flow paths 321 to 325 and the connection flow path 320 flow down from the top to the bottom while repeating the steps gradually (that is, the horizontal flow and the downward flow are alternately repeated). The gas gradually dissolves under pressure in the liquid 72. In the fifth horizontal flow path 325, the concentration of the gas dissolved in the liquid is substantially equal to 60% to 90% of the (saturated) solubility of the gas under a pressurized environment. And the excess gas which did not melt | dissolve in the liquid exists in the 5th horizontal flow path 325 as a bubble of the magnitude | size which can be visually recognized. Since the direction of the flow of the liquid 72 in the horizontal channel adjacent to the upper and lower sides is opposite, the gas dissolving device 3 can be downsized.

  FIG. 4 is an enlarged view showing the damming portion 32a together with the cross section of the horizontal flow path. The dam portion 32a is linear with the upper end 61 being horizontal and perpendicular to the direction in which the channel extends, and has a minute through hole 62 penetrating the dam portion 32a along the horizontal channel at the bottom. The upper side of the upper end 61 is an opening 63 through which the liquid 72 overflowing from the blocking portion 32a flows. When manufacturing the dissolution channel portion 32, first, a plate member is prepared in which a minute through hole 62 and a semicircular opening 63 are formed on a disc having the same size as the cross section of the horizontal channel. Then, welding is performed such that the plate member is sandwiched between the horizontal flow paths 321 to 325 and the connection flow path 320.

  By providing the damming portion 32a, in the first to fourth horizontal flow paths 321 to 324, even when the temperature and viscosity of the liquid 72 change, the height of the liquid level, that is, the water level is maintained approximately constant. The Accordingly, the contact area between the gas and the liquid 72 is maintained approximately constant in the first to fourth horizontal flow paths 321 to 324. As a result, the production capacity of the pressurized liquid 71 can be easily predicted by calculation at the time of design. Moreover, even if the production amount of the pressurizing liquid 71 is changed, it is possible to easily obtain the pressurizing liquid 71 in which a desired amount of gas is dissolved per unit volume.

  In particular, the gas dissolving device 3 is required to have a high degree of cleanliness such as ultrapure water used for semiconductor processing or the like when sanitary cleanliness (so-called sanitary characteristics) such as food or medicine is required. In this case, the cross section of the tube forming the flow path is preferably a circular shape that can be easily mirror-finished, and a sanitary circular tube can be easily obtained. When the flow path cross section is circular, as shown in FIG. 5, the gas-liquid contact area greatly varies due to slight vertical movement of the liquid level as the liquid level moves up and down from the center of the flow path. In FIG. 5, the radius of the horizontal flow path is expressed as “1”, and the larger the absolute value of the increase rate of the gas-liquid contact area, the greater the change in the gas-liquid contact area with respect to the liquid level fluctuation. ing. When the blocking portion 32a is not provided, the liquid level greatly varies depending on the production amount of the pressurized liquid 71. Therefore, it is particularly preferable that the damming portion 32a is provided when the horizontal channel has a circular cross section. The height of the liquid level is preferably maintained at 0.8 to 1.2 in FIG. Moreover, since the gas-liquid contact area can be widely maintained by the damming portion 32a, the gas dissolving device 3 can be downsized.

  Furthermore, since the cross section of the flow path is circular, the pressure resistance performance of the flow path can be improved. Thereby, a pipe wall can be made thin. In addition, as long as the cross section of the inner surface of a flow path is circular, the external shape of a flow path may be other shapes, such as a rectangle.

  The damming portion 32a is provided between the downstream side connection flow path 320 in the first to fourth horizontal flow paths 311 to 314, that is, at a position immediately before the liquid 72 is directed to the next horizontal flow path. Therefore, the contact area between the gas and the liquid can be increased in each horizontal flow path. As a result, the production capacity of the pressurized liquid 71 can be improved.

  Since the minute piercing hole 62 is provided in the damming portion 32a, a part of the liquid 72 dammed by the damming portion 32a is transferred from the minute through hole 62 to the next while the pressurized liquid 71 is produced. It flows out to the horizontal channel. The amount of the liquid 72 flowing out from the minute through hole 62 is small, and the state where the liquid 72 overflows from the damming portion 32a is maintained. For example, the amount of the liquid 72 that flows down from the minute through-hole 62 is 1/5 or less, more preferably 1/10 or less, of the liquid 72 that exceeds the blocking portion 32a. On the other hand, by providing the minute through hole 62, after the production of the pressurized liquid 71 is stopped, the liquid remaining in the dissolution channel portion 32 is naturally connected to the connection pipe 4 side, that is, outside the dissolution channel portion 32. Can be discharged. Therefore, when the sanitary characteristic is required for the dissolution channel portion 32, it is particularly preferable that the dissolution channel portion 32 is provided with the minute through holes 62.

  The dissolution channel unit 32 further includes an excess gas separation unit 326 extending upward from the upper surface on the downstream side of the fifth horizontal channel 325, and the excess gas separation unit 326 is filled with the liquid 72. The surplus gas separation part 326 is divided into two parts at the lower part and connected to the fifth horizontal flow path 325, respectively, and connected to one at the upper part. Each pipe line of the surplus gas separation unit 326 is also circular in cross section. The upper end portion of the surplus gas separation unit 326 is opened to the atmosphere via the throttle unit 327. The bubbles of the liquid 72 flowing through the fifth horizontal flow path 325 rise in the surplus gas separation unit 326 and are discharged together with the surplus liquid 72. By separating the lower part of the surplus gas separation part 326 into two parts, the surplus gas is more reliably separated. In addition, the lower part of the excess gas separation part 326 may be divided into three or more, and may be only one.

  In this way, by separating the excess gas from the liquid 72, the pressurized liquid 71 that does not substantially include bubbles of a size that can be easily visually recognized is generated, and the downstream side of the fifth horizontal flow path 325 is generated. It is sent out to the connecting pipe 4 connected to the end (that is, the right end in FIG. 1). In the present embodiment, the pressurized liquid 71 dissolves a gas that is about twice or more the gas (saturated) solubility under atmospheric pressure. The liquid 72 flowing through the horizontal flow paths 321 to 325 and the connection flow path 320 in the dissolution flow path section 32 can also be regarded as the pressurized liquid 71 in the course of generation.

  The fine bubble generating device 1 further includes a regulating valve 51, a pressure sensor 52, and a valve control unit 53. The adjustment valve 51 is a proportional control valve that is provided in the connection pipe 4 and adjusts the pressure of the pressurized liquid 71 in the connection pipe 4. Of course, the regulating valve 51 may be another type of valve such as a relief valve, a normal valve, or a fixed throttle. The pressure sensor 52 is disposed above the first horizontal channel 321 and measures the pressure in the dissolution channel unit 32. An exhaust valve 54 is also provided above the first horizontal flow path 321. In the fine bubble generating device 1, the measured value of the pressure in the dissolution channel portion 32 output from the pressure sensor 52 is set to a predetermined pressure (preferably, 0.1 MPa to 0.45 MPa). The regulating valve 51 is controlled by the valve control unit 53. In other words, the valve control unit 53 controls the adjustment valve 51 based on the output from the pressure sensor 52. Thereby, even if the viscosity of the liquid 72 changes due to a temperature change, the pressure change in the dissolution channel portion 32 is reduced. The pressurized liquid 71 that has passed through the connection pipe 4 flows into the fine bubble generating nozzle 2. The adjustment valve 51 may be manually operated.

  FIG. 6 is an enlarged cross-sectional view of the fine bubble generating nozzle 2. The fine bubble generating nozzle 2 includes a pressurized liquid inlet 21 through which the pressurized liquid 71 flows from the connection pipe 4 and a pressurized liquid outlet 22 that opens toward the target liquid 92. The pressurized liquid inlet 21 and the pressurized liquid outlet 22 are each substantially circular, and the cross section of the nozzle flow path 20 from the pressurized liquid inlet 21 toward the pressurized liquid outlet 22 is also substantially circular.

  The fine bubble generating nozzle 2 includes an introduction part 23, a taper part 24, and a throat part 25 that are sequentially arranged from the pressurized liquid inlet 21 toward the pressurized liquid outlet 22. In the introduction part 23, the channel area is substantially constant at each position in the direction of the central axis J <b> 2 of the nozzle channel 20. In the taper portion 24, the flow path area gradually decreases in the direction in which the pressurized liquid 71 flows (that is, toward the downstream side). The inner surface of the tapered portion 24 is a part of a substantially conical surface with the central axis J2 of the nozzle channel 20 as the center. In the cross section including the central axis J2, the angle α formed by the inner surface of the tapered portion 24 is preferably 10 ° or more and 90 ° or less.

  The throat part 25 connects the taper part 24 and the pressurized liquid ejection port 22. The inner surface of the throat portion 25 is a substantially cylindrical surface, and the flow path area is substantially constant in the throat portion 25. The diameter of the channel cross section in the throat 25 is the smallest in the nozzle channel 20, and the channel area of the throat 25 is the smallest in the nozzle channel 20. The length of the throat 25 is preferably 1.1 to 10 times the diameter of the throat 25, and more preferably 1.5 to 2 times. In the nozzle channel 20, even if the channel area slightly changes in the throat portion 25, the entire portion having the smallest channel area is regarded as the throat portion 25.

  The fine bubble generating nozzle 2 is also provided continuously to the throat portion 25 and encloses the periphery of the pressurizing liquid jet port 22 away from the pressurizing liquid jet port 22, and the end of the enlarging unit 27 An enlarged portion opening 28 provided in the portion is provided. The flow path 29 between the pressurized liquid jet port 22 and the enlarged portion opening 28 is a flow path provided outside the pressurized liquid jet port 22 and is hereinafter referred to as an “external flow path 29”. The channel cross section of the external channel 29 and the enlarged portion opening 28 are substantially circular, and the channel area of the external channel 29 is substantially constant. The diameter of the external flow path 29 is larger than the diameter of the throat portion 25 (that is, the diameter of the pressurized liquid ejection port 22). In the following description, an annular surface between the edge of the inner peripheral surface of the enlarged portion 27 on the side of the pressurized liquid jet port 22 and the edge of the pressurized liquid jet port 22 is referred to as a “jet port end surface 221”.

  In the present embodiment, the angle formed by the central axis J2 of the nozzle flow path 20 and the external flow path 29 and the jet end face 221 is about 90 °. The diameter of the external channel 29 is 10 mm to 20 mm, and the length of the external channel 29 is approximately equal to the diameter of the external channel 29. In the fine bubble generating nozzle 2, an external channel 29 that is a recess is formed at the end opposite to the pressurizing liquid inlet 21, and the pressurizing liquid that is an opening smaller than the bottom at the bottom of the recess. It can be understood that the spout 22 is formed. In the enlargement unit 27, the flow path area of the pressurized liquid 71 between the pressurized liquid ejection port 22 and the target liquid 92 in the water tank 91 is enlarged.

  In the fine bubble generating nozzle 2, the pressurized liquid 71 that has flowed into the nozzle flow path 20 from the pressurized liquid inlet 21 flows to the throat part 25 while being gradually accelerated in the tapered part 24, and passes through the throat part 25. It is ejected as a jet from the pressurized liquid ejection port 22. The flow rate of the pressurizing liquid 71 in the throat 25 is preferably 10 m to 30 m per second, and in this embodiment is about 20 m per second. In the fine bubble generating device 1, the fine bubble generating nozzle 2 (particularly, the throat portion 25) provided on the feeding path of the pressurized liquid 71 from the gas dissolving device 3 functions as a throttling portion. Pressure is maintained. Precisely, the pressure is maintained by the regulating valve 51 and the fine bubble generating nozzle 2.

  By passing through the throat 25 and being decompressed, the gas in the pressurized liquid 71 becomes supersaturated and precipitates in the liquid as fine bubbles. The fine bubbles pass through the external flow path 29 of the enlarged portion 27 together with the pressurized liquid 71 and diffuse into the target liquid 92 in the water tank 91. In the fine bubble generating nozzle 2, the fine bubbles are deposited while the pressurized liquid 71 passes through the external flow path 29. The fine bubbles generated by the fine bubble generating nozzle 2 are so-called nano bubbles having a diameter of less than 1 μm. When the ejection of the liquid and the fine bubbles from the fine bubble generating nozzle 2 is stopped, the external flow path 29 is filled with the target liquid 92.

  In the fine bubble generating nozzle 2, the tapered portion 24 in which the flow path area gradually decreases in the flowing direction of the pressurized liquid 71 and the throat portion 25 having the smallest flow path area in the nozzle flow path 20 are provided. It is possible to stably generate a large amount of fine bubbles, in particular, fine bubbles (nanobubbles) having a diameter of less than 1 μm.

  In the fine bubble generating nozzle 2, the enlarged portion 27 surrounding the periphery of the pressurized liquid ejection port 22 is provided, so that the flow of the target liquid 92 in the water tank 91 is added immediately after being ejected from the pressurized liquid ejection port 22. An influence on the pressure fluid 71 can be suppressed. Thereby, also in the pressurizing liquid 71 immediately after jetting from the pressurizing liquid jet port 22, nanobubbles are deposited stably, so that a large amount of nanobubbles can be generated more stably.

  As described above, in the fine bubble generating nozzle 2, the inner surface of the tapered portion 24 is a part of a conical surface centered on the central axis J <b> 2 of the nozzle flow path 20, and the tapered portion 24 in the cross section including the central axis J <b> 2. The angle α formed by the inner surface is 90 ° or less. Thereby, a large amount of nanobubbles can be generated more stably. Further, from the viewpoint of shortening the length of the fine bubble generating nozzle 2 while maintaining the diameters of the introduction portion 23 and the throat portion 25 of the fine bubble generating nozzle 2, the angle α formed by the inner surface of the tapered portion 24 is 10 ° or more. It is preferable that

  In the fine bubble generating nozzle 2, the length of the throat portion 25 is 1.1 to 10 times the diameter of the throat portion 25. When the length of the throat part 25 is 1.1 times or more of the diameter, a large amount of nanobubbles can be generated more stably. For example, when the length of the throat 25 is 0.53 times the diameter, the generation density of nanobubbles is about 56 million, whereas the length of the throat 25 is 1.57 times the diameter. The generation density of nanobubbles is about 11 million. Further, since the length of the throat portion 25 is 10 times or less of the diameter, it is possible to prevent the resistance generated in the pressurized liquid 71 in the throat portion 25 from becoming excessively large, and the high accuracy of the throat portion 25. Can be easily formed. From the viewpoint of more stably generating a large amount of nanobubbles, it is more preferable that the length of the throat portion 25 is 1.5 to 2 times the diameter.

  In the fine bubble generating device 1 shown in FIG. 1, when the generation of fine bubbles is stopped, the driving of the pump that pumps the liquid to the mixing nozzle 31 of the gas dissolving device 3 is stopped. The exhaust valve 54 is opened until the liquid flow from the pump to the mixing nozzle 31 stops. Thereby, the pressurized gas in the dissolution flow path portion 32 is released to the outside through the exhaust valve 54. As a result, it is possible to prevent the liquid from flowing back to the mixing nozzle 31 and the pump due to the expansion of the gas in the dissolution channel portion 32. Further, when the connection pipe 4 is removed from the dissolution channel portion 32, as described above, the liquid 72 in the dissolution channel portion 32 flows out to the outside through the minute through hole 62 of the damming portion 32a. To do.

  FIG. 7 is a diagram illustrating another example of the blocking portion 32a. 7 is provided with a beam-like member 60 in a horizontal channel in a direction that is horizontal and perpendicular to the direction in which the channel extends. The liquid 72 flows down over the upper end 61 of the member 60 to the next horizontal flow path. Further, the gap between the lower end of the member 60 and the lower part of the horizontal flow path functions as the minute through hole 62. The operation and effect of the blocking portion 32a in FIG. 7 are the same as those shown in FIG.

  FIG. 8 is a view showing another preferred arrangement of the regulating valve 51 provided in the connection pipe 4. In the fine bubble generating device 1, the adjustment valve 51 is directly provided on the connection pipe 4. Also in this case, similarly to the above, the pressure in the dissolution channel 32 is set to a predetermined value by controlling the regulating valve 51 based on the output from the pressure sensor 52 by the valve controller 53. It becomes pressure. Since the fine bubble generating nozzle 2 is a fixed throttle, the adjustment valve 51 is provided to prevent the influence of pressure fluctuations in the gas dissolving device 3 from reaching the fine bubble generating nozzle 2. The pressure reduction in the regulating valve 51 is desirably 30% or less of the whole, that is, the downstream pressure is 70% or more of the upstream pressure.

  FIG. 9 is a diagram illustrating another example of the portion other than the surplus gas separation unit 326 of the dissolution channel unit 32. In the dissolution flow path portion 32 of FIG. 9, the weir portion 32a is provided with the minute through hole 62 omitted from that shown in FIG. Further, in the dissolution flow path portion 32, a bypass flow path 32b that connects the horizontal flow paths arranged vertically is provided on the upstream side of the damming portion 32a in place of the minute through hole 62. That is, a bypass channel 32b that connects the first horizontal channel 321 and the second horizontal channel 322 up and down is provided on the upstream side of the blocking portion 32a of the first horizontal channel 321, and the second horizontal channel 322 is provided. A bypass channel 32b that connects the second horizontal channel 322 and the third horizontal channel 323 up and down is provided on the upstream side of the damming portion 32a, and the third horizontal channel 323 and the fourth horizontal channel 324 are provided. In the same manner, a bypass channel 32b is also provided between the fourth horizontal channel 324 and the fifth horizontal channel 325. The horizontal channels lined up and down communicate with each other through the connection channel 320, while the bypass channel 32b is a minute channel that separately communicates these horizontal channels. Other structures of the fine bubble generating device 1 and the dissolution flow path section 32 are the same as those shown in FIG.

  Also in the dissolution channel portion 32 of FIG. 9, the height of the liquid surface of the liquid 72 is approximately equal in the first to fourth horizontal channels 321 to 324 by providing the damming portion 32 a as in FIG. 1. Maintained constant. Thereby, the contact area of gas and liquid is maintained substantially constant. As a result, the pressurized liquid 71 in which a desired amount of gas is dissolved per unit volume can be easily obtained. Further, since the damming portion 32a is provided at a position immediately before the liquid 72 is directed to the next horizontal flow path, the contact area between the gas and the liquid can be increased in each horizontal flow path.

  Since the bypass flow path 32b is provided on the upstream side of the damming portion 32a, a part of the liquid 72 dammed up by the damming portion 32a is produced while the pressurized liquid 71 is produced. To the next horizontal channel. The amount of the liquid 72 flowing down from the bypass passage 32b is small, and the state where the liquid 72 overflows from the damming portion 32a is maintained. The amount of the liquid 72 flowing down the bypass channel 32b is 1/5 or less, more preferably 1/10 or less, of the liquid 72 exceeding the blocking portion 32a. On the other hand, by providing the bypass flow path 32b, as in the case of FIG. 1, after the production of the pressurized liquid 71 is stopped, the liquid remaining in the dissolution flow path section 32 is naturally transferred to the connection pipe 4 side. Can be drained.

  The fine through hole 62 in FIG. 4 and the bypass channel 32b in FIG. 9 of the damming portion 32a in FIG. 1 and the bypass channel 32b in FIG. 9 both store the liquid 72 in the upstream horizontal channel by the damming portion 32a. The lower part of the space communicates with the space downstream of the damming portion 32a, and a part of the liquid 72 stored in the upstream horizontal flow path is transferred to the space downstream of the damming portion 32a. It functions as a communication channel to guide. The communication channel having such a function can be easily realized by the structure shown in FIGS. 4 and 9, but the communication channel is not limited to these structures. For example, a communication channel that guides the liquid 72 stored by the damming portion 32 a to the connection channel 320 may be provided. Further, the bypass flow path 32b may be provided away from the damming portion 32a on the upstream side.

  FIG. 10 is a diagram showing still another example of the dissolution flow path section 32 (excluding the excess gas separation section 326). In the dissolution flow path part 32 of FIG. 10, a substantially semicircular plate member is used as the damming part 32a. As in the case of FIG. 1, the damming portion 32 a is a portion that is disposed below the horizontal flow paths 321 to 324 and closes the lower portion. This plate member is provided as another member separated from the horizontal flow path. Below the damming portion 32a and outside the horizontal flow path, there is provided a damming switching portion 32c that rotates the damming portion 32a about an axis that faces the vertical direction. Other structures of the fine bubble generating device 1 and the dissolution flow path portion 32 are the same as those in FIG.

  In the dissolution channel portion 32 of FIG. 10, when the damming switching portion 32 c causes the damming portion 32 a to be in a posture perpendicular to the direction in which the flow channel extends, the damming portion 32 a hinders the flow of the liquid 72 and the horizontal channel Liquid 72 is stored therein. Then, the liquid 72 overflowing beyond the blocking portion 32a flows down to the next horizontal flow path via the connection flow path 320. As a result, as in FIG. 1, the liquid level of the liquid 72 is maintained approximately constant in the first to fourth horizontal flow paths 321 to 324. Further, since the damming portion 32a is provided at a position immediately before the liquid 72 is directed to the next horizontal flow path, the contact area between the gas and the liquid can be increased in each horizontal flow path.

  On the other hand, when the damming portion 32a assumes a posture parallel to the direction in which the flow path extends by the damming switching portion 32c, the liquid 72 flows down to the next horizontal flow path without being blocked by the damming portion 32a. In this way, the damming switching unit 32c changes the state of the damming unit 32a between a state that prevents the flow of the liquid 72 and a state that does not block the flow. When the pressurizing liquid 71 is produced, the blocking portion 32 a is in a state of hindering the flow of the liquid 72. After the production of the pressurized liquid 71 is stopped, the liquid remaining in the dissolution flow path section 32 is removed as in the case of FIG. It can naturally flow out to the connecting pipe 4 side.

  The mechanism for switching the state of the damming portion 32a is not limited to the rotation of the damming portion 32a. For example, the damming switching unit 32c may raise and lower the damming unit 32a. The weir switching part 32c raises the weir part 32a to form a gap between the lower part of the weir part 32a and the inner bottom surface of the horizontal flow path, so that the weir part 32a does not disturb the flow of the liquid 72. It becomes a state. Furthermore, the blocking portion 32a may be formed by a deformable member, and may be changed between a state in which the flow is blocked and a state in which the flow is not blocked.

  As mentioned above, although embodiment of this invention has been described, this invention is not limited to the said embodiment, A various change is possible.

  For example, the cross sections of the horizontal flow paths 321 to 325 and the connection flow path 320 may be rectangular instead of circular. In the dissolution channel section 32, the five horizontal channels 321 to 325 are not necessarily stacked in the vertical direction, and are arranged in a stepped manner so that the mixed fluid flows in the same horizontal channel. May be. Moreover, the number of horizontal flow paths is not limited to five, and may be variously changed. However, by providing another horizontal flow path through which the liquid (mixed fluid) dropped from the flow path to which the mixing nozzle 31 is attached, the amount of gas that is pressurized and dissolved in the liquid can be increased. The horizontal flow path need only be horizontal to the extent that the liquid 72 can be stored, and need not be completely horizontal. The width of the channel need not be constant.

  The mixed fluid may be generated by a mechanism other than the mixing nozzle 31 and introduced into the first horizontal flow path 321. However, by using the mixing nozzle 31, the gas dissolving device 3 can be reduced in size while efficiently dissolving the gas in the liquid. The number of connections between the surplus gas separation unit 326 and the fifth horizontal flow path 325 may be increased or decreased according to the amount of gas separation. In the dissolution channel section 32, the surplus gas separation section 326 may be omitted if the gas supplied from the mixing nozzle 31 is completely dissolved in the liquid 72 before reaching the connection pipe 4.

  The blocking portion 32a does not necessarily have a plate shape, and may be, for example, a block shape as long as the flow of the liquid 72 can be prevented. As shown in FIGS. 4 and 7, the shape of the damming portion 32 a is not limited to the one having the upper end 61 being horizontal, so long as the liquid level of the liquid 72 can be made approximately constant. Various modifications may be made. For example, a triangular weir shown in FIG. 11 or a square weir shown in FIG. 12 may be used. FIG. 13 is a diagram illustrating still another example of the blocking portion 32a. In the dam portion 32a of FIG. 13, the upstream surface is a gently inclined surface that gradually moves upward toward the downstream side. Foreign matter does not collect easily on the surface. Also in the dam member 32a shown in FIG. 13, a minute through hole penetrating in the flow path direction may be provided in the lower part. Further, the blocking portion 32a is not necessarily provided immediately before the liquid 72 falls from the horizontal flow path. Of course, in order to increase the contact area between the gas and the liquid, it is preferable that the blocking portion 32a is provided at a position immediately before heading to the next horizontal flow path, specifically, a horizontal portion of the flow path. It is preferable to be provided at a distance equal to or less than 1/5 of the length of the horizontal portion from the end.

  When the mixing nozzle 31 is used, the liquid level greatly undulates in the first horizontal flow path 321 of the dissolution flow path section 32, so that the damming portion 32 a may not be provided in the first horizontal flow path 321.

  The connection pipe 4 may be branched, and a plurality of fine bubble generating nozzles 2 may be arranged in the target liquid 92. Further, the fine bubble generating nozzle 2 may have a plurality of pressurized liquid ejection ports 22. The internal structure of the fine bubble generating nozzle 2 may also be changed as appropriate.

  For example, the fine bubble generating device 1 is used for generating fine bubbles (so-called micro bubbles) having a diameter of 1 μm or more and less than 1 mm by providing the adjustment valve 51 of FIG. May be. Also in this case, a large amount of microbubbles can be stably generated as in the above embodiment.

  The gas dissolving device 3 may be used for devices other than the fine bubble generating device 1. In this case, for example, the fine bubble generating nozzle 2 is omitted, and the pressurized liquid 71 is directly used for various applications. Further, the gas dissolving device 3 may be used as a device for generating a pressurized liquid by pressure-dissolving various gases in various liquids. For example, it may be used as a gas-liquid reaction device such as a device that dissolves ozone in water or a device that reacts another gas with a liquid. In the configuration shown in FIG. 8, the adjustment valve 51 may be adjusted so that fine bubbles are deposited in the pressurized liquid 71 when it passes through the adjustment valve 51. In this case, the fine bubble generating nozzle 2 may be omitted.

  The configurations in the above-described embodiments and modifications may be combined as appropriate as long as they do not contradict each other.

DESCRIPTION OF SYMBOLS 1 Fine bubble production | generation apparatus 2 Fine bubble production | generation nozzle (throttle part)
DESCRIPTION OF SYMBOLS 3 Gas dissolving apparatus 4 Connection piping 31 Mixing nozzle 32a Damping part 32b Bypass flow path 32c Damping switching part 51 Adjustment valve 52 Pressure sensor 53 Valve control part 62 Micro through-hole 72 Liquid (mixed fluid)
321-324 Horizontal flow path

Claims (12)

A gas dissolving device for dissolving gas in a liquid under pressure,
A first flow path in which a liquid flows under the gas while in contact with the gas under a pressurized environment;
A damming portion that is provided in a lower portion in the first flow path and stores the liquid in the first flow path by preventing the flow of the liquid;
A second flow path that is located below the first flow path and in which the liquid flowing over the blocking portion flows in a pressurized environment;
The liquid stored in the first flow path by connecting the lower portion of the space in which the liquid in the first flow path is stored by the damming portion and the space on the downstream side of the damming portion. A communication channel for guiding a part of the gas to the downstream space;
A gas dissolving apparatus comprising: The gas dissolving apparatus according to claim 1,
The damming portion is a portion that is fixed to a lower portion of the first flow path and closes the lower portion,
The gas dissolving device, wherein the communication channel is a through-hole penetrating the damming portion along the first channel. The gas dissolving apparatus according to claim 1,
The gas dissolving apparatus, wherein the communication channel is a micro channel that separately connects the first channel and the second channel. The gas dissolving apparatus according to any one of claims 1 to 3,
The gas dissolving apparatus according to claim 1, wherein the damming portion is provided at a position immediately before the liquid is directed to the second flow path in the first flow path. A gas dissolving device for dissolving gas in a liquid under pressure,
A first flow path in which a liquid flows under the gas while in contact with the gas under a pressurized environment;
A second channel that is located below the first channel and in which the liquid flowing from the first channel flows in a pressurized environment;
A damming portion that is provided in a lower portion of the first flow path and immediately before the second flow path, and stores the liquid in the first flow path by preventing the flow of the liquid;
With
The gas dissolving device, wherein the liquid flows into the second flow path beyond the damming portion. A gas dissolving device for dissolving gas in a liquid under pressure,
A first flow path in which a liquid flows under the gas while in contact with the gas under a pressurized environment;
A damming portion that is provided in a lower portion in the first flow path and stores the liquid in the first flow path by preventing the flow of the liquid;
A second flow path that is located below the first flow path and in which the liquid flowing over the blocking portion flows in a pressurized environment;
A dam switching unit that changes a state of the damming portion between a state that prevents the flow of the liquid and a state that does not hinder the flow; and
A gas dissolving apparatus comprising: The gas dissolving apparatus according to claim 6,
The damming portion is a portion that is disposed at a lower portion of the first flow path and closes the lower portion,
The gas dissolving apparatus, wherein the damming switching unit is a mechanism for rotating or lifting the damming unit. A gas dissolving device according to any one of claims 1 to 7,
The gas dissolving device according to claim 1, wherein a cross section of an inner surface of the first flow path by a surface perpendicular to a direction in which the first flow path extends is circular. A gas dissolving device according to any one of claims 1 to 8,
In the second flow path, the liquid flows under the gas while in contact with the gas under a pressurized environment,
The direction in which the liquid flows in the first flow path is opposite to the direction in which the liquid flows in the second flow path,
The gas dissolving device is further provided with another damming portion that is provided in a lower portion in the second flow path and stores the liquid in the second flow path by preventing the flow of the liquid. Gas dissolving device. A gas dissolving device according to any one of claims 1 to 9,
A third channel positioned above the first channel;
A mixing nozzle for mixing the gas and the liquid and ejecting the gas into the third flow path;
Further comprising
The mixed fluid ejected from the mixing nozzle in the third flow path flows in a direction opposite to the liquid flow direction in the first flow path in a pressurized environment, and the first flow. A gas dissolving device that flows into a path. A microbubble generator,
A gas dissolving device according to any one of claims 1 to 10,
A throttle that is provided on the liquid delivery path from the gas dissolving device and maintains the pressure in the gas dissolving device;
With
A fine bubble generating apparatus, wherein fine bubbles are generated in the liquid by being reduced in pressure through the throttle unit. It is a fine bubble production | generation apparatus of Claim 11, Comprising:
A connection pipe connecting the gas dissolving device and the throttle part;
An adjustment valve provided in the connection pipe for adjusting the pressure of the liquid in the connection pipe;
A pressure sensor for measuring the pressure in the gas dissolving device;
A valve control unit that controls the regulating valve based on an output from the pressure sensor;
A fine bubble generating apparatus, further comprising:

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