JP4498405B2 - Microbubble generator - Google Patents

Description

  The present invention sucks the liquid in the liquid tank, pressurizes it with a pump, dissolves the gas in the liquid with a pressurized tank installed on the discharge port side of the pump, and then generates fine bubbles with a fine bubble generating nozzle The present invention relates to a fine bubble generating device.

  Conventionally, as shown in FIG. 1, there is a high possibility that a microbubble generator composed of units is installed at a place higher than the liquid level in the liquid tank 13. Therefore, by adopting a self-priming pump, that is, a self-priming pump, as the pump 1 disposed in the fine bubble generating device main body 4, the fine bubble generating device has a self-priming function. This fine bubble generating device is generally composed of main components such as a suction pipe 7, a gas introduction passage 8, a pump 1, a pressurized tank 3, an outlet pipe 12 of the pressurized tank 3, and a fine bubble generating nozzle 6. ing. For example, the liquid in the liquid tank 13 is sucked into the pump 1 while sucking gas from the gas introduction passage 8 through the suction pipe 7 and pressurized, and sent to the pressurizing tank 3 disposed in the discharge port side pipe 2 of the pump 1. Be paid. As a result, the pressure in the pressurized tank 3 is increased by the supplied gas-liquid mixture, and the gas sucked from the gas introduction passage 8 is promoted to be mixed with the liquid.

  In the above apparatus, as a device for mixing the gas with the liquid, the pressurized tank 3 is installed in the discharge port side pipe 2 of the pump 1 and, for example, a pressurized tank in which the gas and the liquid coexist according to Henry's law. A device for increasing the internal pressure, or a device for agitating the liquid and gas pressurized by the pump 1 in the pressurized tank 3 from the nozzle as shown in FIGS. 2 (a) and 2 (b) In addition, there is a device in which a swirl flow is created in a liquid and gas is divided and mixed by the swirl flow. Here, in the device for injecting and stirring the liquid and gas pressurized by the pump 1 from the nozzle into the pressurized tank 3, the nozzle injection port is located above the liquid level in the pressurized tank 3, that is, the pressurized tank. It is important to arrange in the gas in 3. In the pressurized tank 3 pressurized by the operation of the pump 1, an outlet 5 of the pressurized tank 3 is provided at a position where no large bubbles come below the liquid level, and gas is supplied from the outlet 5 to the liquid. When the mixed gas-liquid mixed liquid is flowed to the fine bubble generating nozzle 6, fine bubbles can be generated in the liquid in the liquid tank 13.

  However, for example, in the case of the centrifugal pump shown in FIG. 4, the self-priming pump includes both the impeller chamber 20 and the gas-liquid separation chamber 24, which are also called the casing of the pump 1, and the impeller chamber 20 covers the impeller 21. Yes. Before starting the pump, a certain amount of liquid is stored in the impeller chamber 22 and the gas-liquid separation chamber 24. When the pump is started, the gas in the suction pipe 7 is sucked into the impeller 21 of the pump 1, and the impeller While being mixed with the liquid by the rotation of 21, it is discharged from the discharge port 25 of the impeller chamber 20 to the gas-liquid separation chamber 24. Gas and liquid are separated in the gas-liquid separation chamber 24, the gas is sent to the discharge port 2 a side of the pump, and part of the liquid is again the suction port 7 of the pump 1 or the blades of the gas-liquid separation chamber 24 and the pump 1. Return to the impeller interior 22 from the communication passage 26 with the interior 20.

  On the other hand, in the non-self-priming pump, as shown in FIG. 3, the impeller 21 of the pump 1 rotating without a gas-liquid separation chamber is disposed in the impeller chamber 22, and a suction port, a discharge port, It has. The suction port and the discharge port are also the suction port 7a and the discharge port 2a of the pump. In this non-self-priming pump, liquid is sucked from the suction port 7a by the rotation of the impeller 21 and pressurized in the impeller chamber 22, and then is discharged from the discharge port 2a, and the liquid discharged from the discharge port 2a is discharged. The pump does not return to the suction port 7a of the impeller 21 or the impeller chamber 22 and does not perform gas-liquid separation.

  As described above, the self-priming pump has a gas-liquid separation function, and always has a function of separating gas and liquid during operation during self-priming and when self-priming is completed. Therefore, when a self-priming pump is employed in the fine bubble generating device, it contradicts the function of mixing gas with liquid in the pressurized tank 3 installed in the discharge port side pipe 2 of the pump 1. Therefore, the adoption of the self-priming pump adversely affects the function of generating fine bubbles of the fine bubble generating device. Furthermore, it is necessary to increase the size of the pump and the tank, and the size of the fine bubble generator becomes large. In the first place, the liquid discharged from the impeller outlet 23 is mixed with the gas by the rotation of the impeller 21 of the pump 1, and there is also an effect of promoting the mixing of the gas into the liquid due to the high pressure. Thus, separation of gas and liquid in the rear channel, that is, a gas-liquid separation chamber in the case of a self-priming pump is not preferable.

  Therefore, a non-self-priming pump should be used in the microbubble generator, and as a result, compared to the self-priming pump, the high-efficiency operation of the non-self-priming pump and the compactness of the device that eliminates the gas-liquid separation chamber And so on.

  On the other hand, as a device that reliably separates excess gas from the liquid in the dissolution tank and generates fine bubbles in the liquid storage tank, the direction of the inflow port that forms the inflow path of the liquid tank is directed to the discharge port. An apparatus for generating fine bubbles has been proposed as a different direction (see, for example, Patent Document 1).

  Further, the flow rate of the fluid pumped from the dissolution tank can be reduced without providing a speed reduction member, and the jet in the liquid storage tank can be reliably generated as a gas generating device in the liquid storage tank. There has been proposed a gas generation device that forms an opening area of an outlet larger than the opening area of the inlet and generates fine bubbles in the liquid storage tank by reducing the flow rate of the liquid (for example, Patent Documents). 2).

  Furthermore, a container body having a bottomed cylindrical space, a pressurized liquid inlet opening in a connecting direction on a part of the inner wall circumferential surface of the space, a bottom portion of the cylindrical space, and the cylinder There has been proposed an apparatus for generating fine bubbles on an industrial scale from an apparatus configured from an outlet of a swirling gas-liquid mixture established at the front of a shape space (see, for example, Patent Document 3).

Japanese Patent Laid-Open No. 06-165807 JP 2006-116518 A WO00 / 69550 republication gazette

  The problem to be solved by the present invention is that a non-self-priming pump is used in place of a microbubble generator provided with a pressurized tank disposed on the discharge side of a pump employing a conventional self-priming pump. In order to adopt the self-priming pump as compared with the self-priming pump, the self-priming function is provided to the entire microbubble generator by utilizing the pressurized tank or the rear path of the pressurized tank. Since the non-self-priming pump itself does not have the gas-liquid separation chamber that the self-priming pump itself has, the effect of mixing the gas with the liquid can be enhanced, and the size of the device can be further reduced. It is an object of the present invention to provide a microbubble generator that can be achieved.

  As shown in FIG. 5, the means of the present invention for solving the above-described problem is that, in the invention of claim 1, the liquid is supplied to the discharge side of the pump 1 that sucks fluid from the liquid tank 13 through the suction pipe 7. In the fine bubble generating apparatus provided with the pressurized tank 3 to be mixed, the pump 1 is non-self-priming and pressurized from the outlet 5 of the pressurized tank 3 which is the post-pressure tank 3 or the path behind the pressurized tank 3. A communication passage 9 is provided to connect the outlet pipe 12 of the tank and the fine bubble generating nozzle 6 to the suction pipe 7 or the impeller chamber 22 of the pump 1 so that the liquid in the pressurized tank 3 can return to the impeller chamber 22. Thus, the fine bubble generating device has a structure in which the entire device has a self-priming function.

  As the most effective object, the means of the present invention is such that the fluid discharged from the impeller outlet 23 due to the rotation of the impeller 21 of the pump 1 is in a state where the gas and the liquid are mixed, and the gas generated by the high pressure is generated. It is important to provide the gas introduction passage 8 on the suction pipe 7 side of the pump 1 taking advantage of the effect of promoting mixing with the liquid.

  Therefore, in the invention of claim 2, the gas introduction passage 8 is provided on the suction pipe 7 side of the pump 1, and the gas introduction passage 8 is closed by a method controlled by a valve 8c such as an electromagnetic valve when the device is self-priming. It is a fine bubble generator of the means of Claim 1 which has a structure which is not introduce | transduced.

  Moreover, since the internal pressure of the pressurization tank 3 installed in the discharge side of the pump or the back path of the pressurization tank 3 is pressurized by the pump 1, the suction port 7a side from the discharge port 2a side of the pump 1 is provided. Since the pressure is relatively low, for example, if the pressure tank 3 or the communication passage 9 that connects the rear path of the pressure tank and the suction pipe 7 is provided, the liquid in the pressure tank 3 is sucked into the pump 1. It will be in the state which is easy to return to the mouth 7a side. However, there is also a loss of that amount, and after completing the self-priming by sucking up the liquid, or when there is no need for self-priming depending on the installation location, etc., the device should be operated without the self-priming function. is there.

  Therefore, in the invention of claim 3, when the device does not need self-priming, for example, after completion of self-priming, the gas introduction passage 8 is opened and the pressure tank 3 or the rear path of the pressure tank 3 is connected to the suction pipe 7 Alternatively, the communication passage 9 communicating with the impeller chamber 22 of the pump 1 is closed by a valve 9c such as a valve using the pressure difference (a) or an electromagnetic valve (b) as shown in FIG. The fine bubble generating apparatus according to claim 1 or 2, wherein a structure is provided in which the liquid in the pressure tank (3) cannot return to the impeller chamber (22).

  Furthermore, in order to reduce the self-priming time by utilizing the self-weight of the liquid, the invention according to claim 4 communicates the pressurized tank 3 or the rear path of the pressurized tank 3 with the suction pipe 7 or the impeller chamber 22 of the pump 1. The communication passage 9 is provided, and the communication port 9a on the rear path side of the pressurized tank 3 or the pressurized tank 3 is disposed at a position higher than the communication port 9b on the suction pipe 7 or the impeller chamber 20 side. 4. A fine bubble generating apparatus according to any one of items 3 above.

  In order to increase the self-priming height of the fine bubble generating device, as shown in FIG. 7, in the invention of claim 5, in the invention, the pressure tank 3 communicates with the suction pipe 7 or the impeller chamber 22 of the pump 1. The fine bubble generating device according to any one of claims 1 to 4, wherein a communication port 9a on the side of the pressurized tank 3 of the communicating passage 9 is disposed at a position lower than the outlet 5 of the pressurized tank 3. It is.

  Moreover, although the internal pressure of the suction pipe 7 is designed to be lower than the external pressure of the suction pipe 7 during the pump operation, it may not be so when the pump is stopped. Therefore, in particular, when the valve 8c, which is an electromagnetic valve, is not provided in the gas introduction passage 8, a check valve 8d that does not leak the fluid in the suction pipe 7 from the gas introduction passage 8 should be provided as shown in FIG. is there. Further, it is necessary to close the gas introduction passage 8 and not introduce gas when the fine bubble generating device is self-priming. As a solution for these problems, a valve 8c such as an electromagnetic valve is required as in the apparatus of claim 2. Moreover, although the number of parts increases, as another method, there is a means for increasing the internal pressure of the gas introduction passage 8 when the apparatus is self-priming.

  Therefore, as shown in FIG. 9, in the invention of claim 6, the gas introduction passage 8 is provided in the suction pipe 7, and the pressurization tank 3 or the rear path of the pressurization tank 3 communicates with the suction pipe 7 of the pump 1. The fine bubble generating device according to any one of claims 1 to 5, wherein a passage 9 is provided, and the communication port 9b on the suction pipe 7 side is arranged in a front path of the suction pipe side inlet 8b of the gas introduction passage 8. is there. In this case, the front path of the suction pipe side inlet 8b of the gas introduction passage 8 is a portion between the suction pipe side inlet 8b and the gas inlet 8a of the gas introduction path 8 as shown in FIG. Further, as shown in FIG. 9B, the portion of the suction pipe 7 before the position of the suction pipe side inlet 8b of the gas introduction passage 8 is also indicated.

  The operation of the present invention will be described. Conventionally, as shown in FIG. 1, the fine bubble generating device main body 4 composed of the pump 1 and the pressurized tank 3 may be installed higher than the liquid level in the liquid tank 13. May be large. In this case, a self-priming pump is employed as the unit for generating fine bubbles, and the device itself has a self-priming function. However, as shown in FIG. 4, the self-priming pump includes both the impeller chamber 20 and the gas-liquid separation chamber 24, and performs gas-liquid separation when the pump is in operation. Therefore, if the pressurized tank 3 is disposed on the discharge port 2a side of the pump, the pressurized tank 3 has the principle of generating fine bubbles that mix the gas with the liquid, so the self-priming pump is contrary to this principle. Become. Therefore, it is assumed that a non-self-priming pump is used, and by using this pump, the apparatus can be considerably reduced in size and the pump can be made more efficient.

  On the other hand, the non-self-priming pump is not provided with a communication path through which liquid discharged from the discharge port 2a of the impeller chamber 20 which is also a casing returns to the impeller chamber 22 again. Therefore, particularly when self-priming is required, the non-self-priming pump is pressurized and the liquid discharged from the pump discharge port 2a is returned to the pump suction port 7a side, that is, the impeller chamber 22, and the pump If the discharge port 2a is provided with a space for storing a certain amount of liquid, high self-priming performance such as self-priming height and self-priming time cannot be expected, but self-priming performance can be given to a non-self-priming pump. It should be possible. On the other hand, as shown in FIG. 2, the microbubble generator in which the pressurized tank 3 is provided on the discharge port 2a side of the pump has the function of mixing the gas with the liquid inside, as shown in FIG. Sometimes many gases and liquids coexist in the pressurized tank 3. Furthermore, in order to mix the gas with the liquid, the fine bubble generating device is pressurized by the pump 1 to the pressurized tank 3, for example, a means for increasing the pressure of the gas in the pressurized tank 3 according to Henry's law. A means for stirring or mixing the liquid and the gas with a nozzle, a means for giving a swirl to the liquid, and a means for splitting the gas by the swirling flow are included. In any means, Henry's law is fundamental, and the contact area between the gas and the liquid has to be increased in response to the necessity of mixing many gases with the liquid. The pressurized tank 3 that is larger than the internal volume of the impeller chamber 20 is required.

Instead of adopting a self-priming pump for the microbubble generator , a non-self-priming pump 1 is employed to communicate the inside of the pressurized tank 3 or the rear path of the pressurized tank 3 with the suction pipe 7 of the pump 1. For example, the internal pressure of the pressure tank 3 disposed on the discharge port 2a side of the pump 1 or the outlet pipe 12 of the pressure tank 3 which is the rear path of the pressure tank 3 and the fine bubble generating nozzle 6 in the liquid tank 13 are not Due to the pressurization of the self-priming pump 1, the pressure becomes higher than the suction port 7 a side of the pump 1. Accordingly, the liquid pressurized and discharged by the pump 1 can return to the impeller chamber 22 again. Further, when the impeller 21 is a semi-open impeller or an open impeller centrifugal type or a Wesco pump impeller vortex type, even if the impeller 21 communicates with the impeller chamber 22, the liquid discharged by being pressurized by the pump 1 is discharged. Can return to the impeller chamber 22 again. Thereby, the gas inside the suction pipe 7 of the pump 1 can be gradually discharged to the pressurized tank 3 together with the liquid. Moreover, as shown in FIG. 1, the self-priming height of the apparatus is almost 2 meters or less depending on the installation location of the fine bubble generating apparatus, etc., and the pump 1 is pumped from the liquid level in the liquid tank 13 which is the self-priming height. If the internal volume of the pressurized tank 3 is made larger than the internal volume of the suction pipe 7 of the pump 1 up to the suction port 7a, the pressurized tank 3 has a volume that encloses the gas in the suction pipe 7 of the pump 1. Accordingly, if a predetermined liquid is stored in the pressurized tank 3 in advance before the pump 1 is started, although the self-priming performance such as self-priming height and self-priming time cannot be expected in the fine bubble generating device, the device As a self-priming function.

  In addition, when the gas introduction passage 8 is arranged in the suction pipe 7 of the pump 1 in order to make full use of the effect of promoting the mixing of the gas and the liquid by the rotation of the impeller 21 and to shorten the time until completion of self-priming. During self-priming, the suction pipe 7 of the pump 1 has a negative pressure and is in a state in which gas is easily sucked, and a large amount of gas is sucked from the suction pipe 7, so that the impeller 21 of the pump 1 is completely operated. Since the pressure discharged from the impeller outlet 23 is very low compared to after completion of self-priming, the gas introduction passage 8 installed on the suction pipe 7 side of the pump 1 during self-priming. It is important to close the.

  Further, since the pressure tank 3 provided on the discharge side of the pump 1 or the rear path of the pressure tank 3 has a higher pressure than the suction pipe 7 side, a communication passage 9 that communicates these portions with the suction pipe 7 is provided. If provided, return reflux to the suction pipe 7 occurs both during and after self-priming. It is important to control the return reflux of the pump 1 when high efficiency operation is desired and there is no need for device self-priming or after completion of self-priming. The closing method can be controlled, for example, by providing the communication passage 9 with a valve 9c such as a valve or an electromagnetic valve that uses a difference in discharge pressure during and after completion of self-priming.

Furthermore, if the flow rate of the liquid returning to the impeller chamber 22 of the pump 1 is largely related to the self-priming speed and the liquid self-weight is utilized, the self-priming time of the apparatus can be shortened. Therefore, in the present invention, the communication passage 9 is provided that communicates with the pressurized tank 3 or the rear passage of the pressurized tank 3 and the suction pipe 7 or the impeller chamber 22. Since the liquid easily flows from a high place to a low place, the communication port 9a on the rear path side of the pressurized tank 3 or the pressurized tank 3 is arranged at a position higher than the communication port 9b on the suction pipe 7 or the impeller chamber 20 side. For example, as an arrangement of the suction pipe 7, which is an internal part of the fine bubble generating device , the pump 1, the pressurized tank 3, the fine bubble generating nozzle 6, and the like, a liquid for self-priming is previously added. The pressurized tank 3 is disposed at the upper part of the communication port 9 b on the suction pipe 7 side of the pump 1 or the upper part of the impeller chamber 20. Further, in order to increase the height of self-priming as a device, in the pressurized tank 3 that contains liquid for self-priming in advance, the communication path that connects the pressurized tank 3 to the suction pipe 7 or the impeller chamber 22 9, and the communication port 9 a on the pressurized tank 3 side is disposed below the outlet 5 of the pressurized tank 3, there is a gas amount on the suction pipe 7 side that exceeds the internal volume of the pressurized tank 3. However, there is no risk that all of the priming liquid is discharged from the outlet 5 of the pressurized tank 3 during self-priming, and the gas can be discharged from the outlet 5 of the pressurized tank 3, so that the self-priming height of the device Can be increased.

  Further, the closing of the gas introduction passage 8 during the device self-priming can be controlled by providing the gas introduction passage 8 with a valve 8c made of, for example, an electromagnetic valve. However, the valve 8c is required in this way, and the number of parts increases. As another method, the suction pipe side inlet 8b of the gas introduction passage 8 is closed with the liquid in the pressurized tank 3 pressurized by the pump 1 or the downstream path of the pressurized tank 3. For example, a communication passage 9 that communicates the pressurized tank 3 or the rear path of the pressurized tank 3 with the suction pipe 7 is provided, and the communication port 9 b on the suction pipe 7 side is connected to the front path of the suction pipe side inlet 8 b of the gas introduction path 8. Arranged at a portion between the suction pipe side inlet 8b of the gas introduction passage 8 and the gas inlet 8a with the check valve 8d, or a suction pipe upstream of the position of the suction pipe side inlet 8b of the gas introduction passage 8 If the pressure of the liquid sent as a return reflux from the pressurized tank 3 is high, the suction pipe side inlet 8b of the gas introduction passage 8 is closed and the introduction of the gas is closed. become. However, when the pressure of the liquid is insufficient in the pressurized tank 3 or the rear path of the pressurized tank 3 during self-priming, it is necessary to set the rotational speed of the impeller 21 of the pump 1 high. In addition, after completion of self-priming, the pressurized tank 3 or the communication path 9 that connects the rear path of the pressurized tank 3 to the suction pipe 7 of the pump 1 is closed, but the gas amount in the pressurized tank 3 needs to be adjusted. In this case, the adjustment can be performed by opening / closing the communication passage 9 or opening / closing a part of the passage.

  As a whole, in the present invention, the fine bubble generating device of the pressurized tank 3 provided on the discharge port 2a side of the pump 1 has a function of mixing the gas with the liquid in the pressurized tank 3, and a new gas and liquid during self-priming. The function of separating is given. In particular, in the case of a centrifugal pump, since the gas-liquid separation chamber 24 for self-priming is large, if the gas-liquid separation chamber 24 can be eliminated, the device can be considerably reduced in size.

  As described above, the present invention is not limited to the self-priming pump, and the fine bubble generating apparatus having the pressurizing tank installed on the discharge side of the non-self-priming pump Alternatively, by utilizing the rear path of the pressurized tank, the entire device can be provided with a self-priming function, whereby high-efficiency operation of the fine bubble generating device can be achieved, and the structure of the non-self-priming pump Although the present invention is simple, it is possible to reduce the size of the microbubble generator, and the present invention has an excellent effect that has never been achieved.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic view of a conventional fine bubble generator. FIG. 2 is a view showing an embodiment of the pressurized tank portion in FIG. FIG. 3 is a partial cross-sectional view of the structure of the non-self-priming centrifugal pump. FIG. 4 is a partial cross-sectional view showing the structure of the self-priming pump. FIG. 5 is a view showing an embodiment of the fine bubble generating apparatus of the present invention. FIG. 6 is a diagram showing an example of a valve structure using a pressure difference. FIG. 7 is a view showing an embodiment of the fine bubble generating apparatus of the present invention. FIG. 8 is a view showing a partial structure of the gas introduction passage as an example. FIG. 9 is a view showing an embodiment of the fine bubble generating apparatus of the present invention. FIG. 10 is a diagram showing the self-priming performance of the fine bubble generator of the present invention.

  As shown in FIG. 5, in the fine bubble generating apparatus of the present invention, a pressurized tank 3 for mixing gas with liquid is provided in the discharge port side pipe 2 of the pump 1 for sucking fluid from the liquid tank 13 through the suction pipe 7. 5, the pump 1 is the non-self-priming centrifugal pump shown in FIG. 3, and the outlet pipe 12 of the pressurized tank 3 or the fine bubble generating nozzle 6 is connected to the suction pipe 7 or The entire device has a self-priming function by communicating with the impeller chamber 22 of the non-self-priming centrifugal pump shown in FIG. 3 and allowing the liquid in the pressurized tank 3 to return to the impeller chamber 22. Is a fine bubble generator characterized by the above. A gas introduction passage 8 is provided on the suction pipe 7 side of the pump 1, and before the pump 1 is operated, a certain liquid is stored in the pressurized tank 3 in advance for self-priming, and the suction pipe is stored so that the liquid can be stored. 7 and the position of the outlet pipe 12 of the pressurized tank are raised above the liquid level of the pressurized tank 3. When the pump 1 is turned on, the valve 8c made of, for example, an electromagnetic valve is controlled so as to close the gas introduction passage 8, and further, for example, by opening the valve 9c made of an electromagnetic valve, the liquid in the pressurized tank 3 can be Via the outlet 5 and the communication passage 9 of the pressurized tank 3, the pump 1 bypasses and flows into the suction pipe 7 on the suction port 7 a side, and the gas in the suction pipe 7 is gradually sent into the pressurized tank 3. When all of the gas in the suction pipe 7 is discharged into the pressurized tank 3, the inside of the pump 1 is filled with liquid, and self-priming is completed. After completion of self-priming or when self-priming is not necessary, it is better to increase the output of the pump 1, open the valve 8c of the gas introduction passage 8, and close the communication passage 9 with the valve 9c. The gas from the introduction passage 8 and the liquid from the suction pipe 7 are pressurized by the pump 1. Thereafter, the gas is further mixed with the liquid in the pressurized tank 3, and the liquid mixed with the gas flows from the outlet pipe 12 of the pressurized tank 3 to the fine bubble generating nozzle 6.

  On the other hand, if the communication passage 9 is not provided with, for example, a valve 9c made of an electromagnetic valve, unnecessary loss occurs after completion of self-priming or when self-priming is not necessary, and the internal pressure in the pressurized tank 3 also decreases. To do. Therefore, as an embodiment of the present invention, at the time of self-priming, the valve 8c made of an electromagnetic valve attached in the gas introduction passage 8 is closed, and further the valve 9c made of an electromagnetic valve of the communication passage 9 is opened. When self-priming is not necessary or when there is no need for self-priming, the valve 8c is opened, and the valve 9c comprising an electromagnetic valve is further closed. The arrow in each pipe line of FIG. 7 shows the flow direction at the time of self-priming, and the arrow in each pipe line of FIG. 5 shows the flow direction when self-suction is completed or when self-suction is not necessary.

  Furthermore, in the embodiment of the present invention, as shown in FIG. 5 or FIG. 7, since the pressurized tank 3 is a blow molded product manufactured by blow molding, the liquid easily flows from a high place to a low place. The pressurized tank 3 or the rear path of the pressurized tank 3 communicates with the suction pipe 7 and the impeller chamber 22 of the pump 1, and the communicating path 9 has a communication port 9 a on the rear path side of the pressurized tank 3 or the pressurized tank. Is positioned higher than the suction pipe 7 or the communication port 9b on the impeller chamber 22 side of the pump 1, and the pressurized tank 3 is placed above the communication port 9b on the suction port 7a side of the pump 1 or the pump. It arrange | positions at the upper part of the 1 impeller chamber 22. FIG. By the way, in the above rear path, there are an outlet 5 of the pressurized tank, an outlet pipe 12 of the pressurized tank, and a fine bubble generating nozzle 6.

  Further, in the above embodiment, in order to improve the self-priming performance of the entire apparatus, as shown in FIG. 7, the pressurized tank 3 is sucked into the pressurized tank 3 in which liquid for self-priming is previously contained. If the communication port 9 communicates with the impeller chamber 22 of the pipe 7 or the pump 1 and the communication port 9 a on the pressurized tank 3 side is disposed below the outlet 5 of the pressurized tank 3 in this communication path 9, the pressurized tank 3 Even when there is an amount of gas in the suction pipe 7 that exceeds the internal volume of the tank, there is no risk that all of the liquid is discharged from the outlet 5 of the pressurized tank 3 during self-priming, and the gas is Since it can come out from the exit 5, the self-priming height as an apparatus can be raised.

  Further, in the above-described embodiment, a valve 8c made of, for example, an electromagnetic valve is provided in the gas introduction passage 8 so as not to introduce gas from the gas introduction passage 8 during self-priming. As another method, there is a method of increasing the internal pressure of the gas introduction passage 8 when the apparatus is self-priming. That is, as shown in FIG. 9 (a), the gas introduction passage 8 is provided on the suction pipe 7 side, and the pressurized tank 3 or the rear path of the pressurized tank 3 communicates with the suction pipe 7 of the pump 1. The communication port 9b on the suction pipe side of the passage 9 is disposed in the front path of the suction pipe side inlet 8b of the gas introduction passage 8, and communicates with the suction pipe 7 from the suction officer side inlet 8b.

  Thus, the front path of the suction pipe side inlet 8b of the gas introduction passage 8 is a portion between the suction pipe side inlet 8b and the gas inlet 8a of the gas introduction path 8 as shown in FIG. Further, as shown in FIG. 9B, the portion of the suction pipe 7 opposite to the direction in which the fluid flows into the suction pipe upstream of the position of the suction pipe side inlet 8b of the gas introduction passage 8 is also provided. Point to.

It is a figure which shows the outline of fine bubble generation | occurrence | production. It is typical sectional drawing of an example of a pressurized tank. It is typical sectional drawing of an example of a non-self-priming pump. It is a typical sectional view of an example of a self-priming centrifugal pump. It is typical sectional drawing of one Example of the microbubble generator of this invention. It is a typical sectional view of an example of a valve using a pressure difference. It is typical sectional drawing of one Example of the microbubble generator of this invention. It is a typical sectional view of an example of a gas introduction passage. (A) It is typical sectional drawing of one Example of the microbubble generator of this invention. (b) It is typical sectional drawing of one Example of the microbubble generator of this invention. It is a figure which shows the self-priming performance of the microbubble generator of this invention.

DESCRIPTION OF SYMBOLS 1 Pump 2 Discharge port side piping 2a Discharge port 3 Pressure tank 4 Fine bubble generator main body 5 Outlet 6 Fine bubble generation nozzle 7 Suction pipe 7a Suction port 8 Gas introduction passage 8a Gas inlet 8b Suction pipe side inlet 8c Valve 8d Check Valve 9 Communication path 9a Communication port (Pressurized tank or rear path side of pressurized tank)
9b Communication port (suction pipe or impeller side)
9c valve 12 outlet pipe 13 liquid tank 20 impeller chamber 21 impeller 22 impeller chamber 23 impeller outlet 24 gas-liquid separation chamber 25 discharge port 26 communication path

Claims (6)

Fine bubble generating device provided with a pressurized tank (3) that mixes gas with liquid to make gas-liquid mixed liquid on the discharge port (2a) side of pump (1) that sucks fluid with suction pipe (7) The pump (1) is non-self-priming and communicates with the suction pipe (7) or the impeller chamber (22) of the pump (1) in the rear path of the pressurized tank (3) or the pressurized tank (3). Provide a communication path (9), and allow the liquid in the pressurized tank (3) to return to the impeller chamber (22) of the pump (1), so that the entire device has a self-priming function. A microbubble generator characterized by the above.   2. The fine structure according to claim 1, wherein the gas introduction passage (8) is provided on the suction pipe (7) side, and has a structure in which the gas introduction passage (8) is closed and gas is not introduced when the apparatus self-primes. Bubble generator.   When there is no necessity for the device self-priming, the gas introduction passage (8) is opened, and the rear path of the pressurized tank (3) or the pressurized tank (3) is passed through the suction pipe 7 or the impeller chamber of the pump (1) ( 22) The communication passage (9) communicating with 22) is closed, and the liquid in the pressurized tank (3) has a structure that cannot return to the impeller chamber (22) of the pump (1). 2. The fine bubble generator according to 2.   The pressurized tank (3) or the pressurized tank (3) is provided with a communication passage (9) that communicates the rear path with the suction pipe (7) or the impeller chamber (22) of the pump (1). ) Or the communication port (9a) on the rear path side of the pressurized tank (3) is positioned higher than the communication port (9b) on the impeller chamber (22) side of the suction pipe (7) or the pump (1). The microbubble generator according to any one of claims 1 to 3, wherein:   A communication passage (9) for communicating the pressurized tank (3) with the suction pipe (7) or the impeller chamber (22) of the pump (1) is provided, and a communication port (9a) on the pressurized tank (3) side is added. The fine bubble generating device according to any one of claims 1 to 4, wherein the fine bubble generating device is disposed at a position lower than an outlet (5) of the pressure tank (3). A gas introduction passage (8) is provided in the suction pipe (7), and a communication passage (9) is provided to communicate the rear path of the pressurized tank (3) or the pressurized tank (3) to the suction pipe (7) side. The communication port (9b) on the side of the pipe (7) is arranged in the front path of the suction pipe side inlet (8b) of the gas introduction passage (8). The microbubble generator described.

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