JP4916243B2 - Microbubble generator - Google Patents

Description

The present invention relates to a liquid pump that boosts the liquid sucked from the suction port by a centrifugal action accompanying the rotation of the impeller and discharges it from the discharge port, and a gas introduction that introduces gas into the liquid sucked into the suction port of the liquid pump And a pressure reducing part that decompresses the liquid discharged from the liquid pump and supplies the liquid into the tank,
After the liquid into which the gas is introduced by the gas introduction unit is pressurized by the liquid pump, the pressure is reduced by the decompression unit and supplied into the tank, so that fine bubbles are generated in the liquid stored in the tank. The present invention relates to a fine bubble generation apparatus including a control unit capable of executing a fine bubble generation operation.

  The technique of generating fine bubbles (microbubbles) of gas such as air in a liquid such as water has been originally used as a pressurized flotation method in sewage sludge treatment. Recently, it has been found that fine bubbles have various useful effects such as charging effect, compression effect, and life activity effect. In particular, regarding the life activity effect, there is a report that bathing in bathtub water in which fine bubbles are generated has a blood flow promoting effect and is excellent in a warm bath effect.

  As a microbubble generator for generating such microbubbles, the liquid into which the gas has been introduced by the gas introduction section is pressurized and further stirred by a liquid pump, so that the gas is dissolved at a high concentration in the liquid. There is known a configuration in which a gas solution is decompressed by a decompression unit and supplied into a tank so that a gas is precipitated from the gas solution as the fine bubbles (see Patent Document 1 or 2). .)

Patent Document 1 discloses an accumulator that functions as a gas-liquid separation unit that separates and discharges undissolved gas from a liquid discharged from a liquid pump, a water level detection unit that detects the liquid level of the liquid in the accumulator, and An open / close valve capable of intermittently discharging the undissolved gas separated by the accumulator, and controlling the open / close valve based on the detection result of the water level detection means to stabilize the liquid level of the liquid in the accumulator, It is configured to prevent liquid from being discharged through the on-off valve or undissolved gas from being discharged into the tank as a large bubble through the spout without being discharged.
In addition, the fine bubble generating device described in Patent Document 1 is configured to introduce gas into the liquid from the gas supply pipe serving as the gas introduction unit, and the gas introduction amount is kept constant. Yes.

The above-mentioned Patent Document 2 is a microbubble generator that generates microbubbles in a liquid stored in a reactor tank, while keeping the pressure in the surplus gas separation tank functioning as the gas-liquid separation section constant. By providing a vent valve that discharges the undissolved gas separated in the separation tank, the gas separation liquid in which the gas is dissolved at a high concentration is stored in the separation tank. Yes.
In the microbubble generator described in Patent Document 2, a vortex pump is used as the liquid pump, in which the liquid sucked from the suction port is boosted by the centrifugal action accompanying the rotation of the impeller and discharged from the discharge port. The vortex pump is configured to dissolve the gas in the liquid at a high concentration by simultaneously performing pressurization, aeration, agitation, mixing, and transfer of the liquid into which the gas has been introduced.
Moreover, in this patent document 2, when introduce | transducing gas with respect to a liquid from the gas suction conduit as said gas introduction part, it is not comprised so that the gas introduction amount may be set.

Japanese Examined Patent Publication No. 7-114948 (Fig. 1 etc.) Japanese Patent Laying-Open No. 2005-152663 (FIG. 6 etc.)

  In the conventional fine bubble generator as described above, it is important to generate a sufficient amount of fine bubbles in the entire tank. Therefore, as a method for generating a sufficient amount of fine bubbles, a large amount of gas is introduced into the liquid in the gas introduction unit, so that a large amount of gas is brought into contact with the liquid in the liquid pump. It is conceivable to increase the gas solubility with respect to.

  However, if the gas introduction amount in the gas introduction part is increased in this way, the gas tends to stay in the liquid pump, and if the gas introduction amount is increased excessively, the gas lock phenomenon (the gas is There is a problem that the liquid pump stays at the inlet of the impeller and the liquid pump does not suck the liquid (sometimes referred to as “air lock phenomenon”). When such a gas lock phenomenon occurs, the liquid pump may be stopped or damaged, and it is difficult to increase the gas introduction amount appropriately and sufficiently.

  In addition, even when the gas introduction amount in the gas introduction part is set near the upper limit within a range in which the gas lock phenomenon can be avoided under standard conditions, for example, the condition due to the change in the water level in the tank, etc. The above-mentioned gas lock phenomenon may occur temporarily due to the change in the pressure, and there is a problem that a stable operation state cannot be maintained.

  The present invention has been made in view of the above problems, and its purpose is to generate a gas-dissolved liquid by pressurizing and stirring the liquid into which the gas has been introduced by the gas introduction section with a liquid pump. In the microbubble generator that generates microbubbles in the liquid stored in the tank by depressurizing the gas solution by the decompression unit and supplying it into the tank, a sufficient amount of microbubbles is stabilized in the entire tank. It is to provide the technology to be generated.

In order to achieve the above object, a microbubble generator according to the present invention includes a liquid pump that boosts the liquid sucked from the suction port by a centrifugal action accompanying the rotation of the impeller and discharges the liquid from the discharge port, and the suction of the liquid pump A gas introduction part that introduces gas into the liquid sucked into the mouth, and a pressure reduction part that decompresses the liquid discharged from the liquid pump and supplies the liquid into the tank,
After the liquid into which the gas is introduced by the gas introduction unit is pressurized by the liquid pump, the pressure is reduced by the decompression unit and supplied into the tank, so that fine bubbles are generated in the liquid stored in the tank. A fine bubble generating apparatus provided with a control means capable of executing a fine bubble generating operation to be generated, the first characteristic configuration of which is
A gas introduction amount adjusting means capable of adjusting a gas introduction amount by the gas introduction unit;
A state detecting means for detecting the state of the liquid pump,
Said control means sets the gas introduction amount to the liquid the in fine bubble generating operation by the gas introduction amount adjusting means so as to maintain the state of the liquid pump detected by the state detecting means within the target range Configured to execute the gas introduction amount setting process ,
In the microbubble generation operation, the control means starts the operation of the liquid pump in a state where the gas introduction by the gas introduction unit and the pressure reduction of the liquid by the pressure reduction unit are stopped, and the output of the liquid pump is Execute pump output setting processing to set the rotational torque to be the target rotational torque range upper limit value,
Next, a differential pressure setting process for starting the pressure reduction of the liquid by the pressure reducing unit in a state where the introduction of the gas by the gas introducing unit is stopped and setting the primary pressure of the pressure reducing unit within a target range,
Next, the rotational speed of the liquid pump at the present time is set as the rotational speed before adjustment, and when the rotational speed of the liquid pump is smaller than the target rotational speed lower limit value that is larger than the rotational speed before adjustment, the gas introduction amount is increased. The rotation speed of the liquid pump is increased, and when the rotation speed of the liquid pump is larger than the target rotation speed upper limit value, control is performed to decrease the rotation speed of the liquid pump by decreasing the gas introduction amount. And performing the first gas introduction amount setting process as the gas introduction amount setting process for setting the gas introduction amount to a value larger than the target gas introduction amount lower limit value and smaller than the target gas introduction amount upper limit value,
Next, when the gas introduction amount introduced by the gas introduction part is smaller than the target gas introduction amount upper limit value, the second gas introduction amount setting as the gas introduction amount setting process for shifting the gas introduction amount to the increase side The point is to execute the process .

According to the first characteristic configuration, the control unit executes the gas introduction amount setting process in the fine bubble generation operation, thereby suppressing the liquid pump from being stopped or damaged due to a gas lock phenomenon. As much gas as possible can be introduced to the liquid in the gas introduction part while maintaining the stable state to be obtained, so that the liquid pump can stably contact as much gas as possible with the liquid, and the concentration is as high as possible. The gas solution can be produced. Therefore, by decompressing the high-concentration gas solution by the decompression unit and supplying it to the tank, a sufficient amount of fine bubbles can be stably generated in the liquid stored in the tank.
Further, according to the above characteristic configuration, even when there is a change in conditions such as a change in the water level in the tank, for example, the control means shifts the gas introduction amount to the increase side in the gas introduction amount setting process. In the range where the liquid pump can be maintained in a stable state, as much gas as possible can be introduced into the liquid according to the conditions at that time, and as many fine bubbles as possible in the liquid stored in the tank Can be generated.
Furthermore, according to the characteristic configuration, the pump output setting process, the differential pressure setting process, and the first gas introduction amount setting process and the second gas introduction amount setting process which are the gas introduction amount setting process are sequentially executed. Thus, the operation for generating fine bubbles can be started.
That is, when starting the microbubble generation operation, the operation of the liquid pump is stably started in a state in which the introduction of the gas by the gas introduction unit and the depressurization of the liquid by the decompression unit are stopped to reduce the load on the liquid pump. By executing the pump output setting process, the output of the liquid pump is set to a value that can be an appropriate output when gas introduction by the gas introduction unit and liquid decompression by the pressure reduction unit are started later. Can do. Next, by starting the pressure reduction of the liquid by the pressure reducing part and executing the pressure difference setting process, the pressure difference of the pressure reducing part is appropriately set when gas introduction by the gas introducing part is started later. It can be set to be capable of generating fine bubbles.
Then, after setting the output of the liquid pump and the differential pressure of the pressure reducing unit to be appropriate as described above, the introduction of the gas by the gas introducing unit is started, and the gas introduction amount setting process described so far is performed. By executing, while maintaining the liquid pump in a stable state that can suppress the gas lock phenomenon, gas introduction into the gas introduction part is started, and the gas introduction amount is increased as much as possible and stored in the tank. It is possible to generate a sufficient amount of fine bubbles in the liquid being applied.

  The second characteristic configuration of the microbubble generator according to the present invention is that, in addition to the first characteristic configuration, the tank is a bathtub, the liquid is bathtub water, and the gas is air.

  According to the second feature configuration, since a sufficient amount of fine bubbles can be stably generated in the bathtub water stored in the bathtub, the bath water in which the sufficient amount of fine bubbles is generated is obtained. Further bathing effect and warm bath effect can be obtained by bathing.

According to a third characteristic configuration of the microbubble generator according to the present invention, in addition to the first or second characteristic configuration described above, the state detection unit may be configured to determine a rotational speed and a rotational torque of the liquid pump as the state of the liquid pump. The point is to detect the state.

According to the third characteristic configuration, when the gas lock phenomenon of the liquid pump proceeds by increasing the amount of gas introduced into the liquid by the gas introduction unit, the work amount of the liquid pump obtained from the rotational speed and rotational torque of the liquid pump is increased. It will increase rapidly. Therefore, if the state detection means detects the rotation speed and torque of these liquid pumps as the state of the liquid pump, the occurrence of the gas lock phenomenon of the liquid pump due to the excessive amount of introduced gas from the state of the liquid pump is good. While predicting, it is possible to generate as many fine bubbles as possible by appropriately increasing the gas introduction amount within a range in which the occurrence of the gas lock phenomenon can be avoided.

A fourth characteristic configuration of the microbubble generator according to the present invention is that, in addition to any of the first to third characteristic configurations, the liquid pump is a vortex pump.

According to the fourth characteristic configuration, by using the vortex pump as the liquid pump, the liquid into which the gas has been introduced is satisfactorily stirred by the vortex generated between the impeller and the passage. The gas solubility with respect to the liquid can be improved, and as a result, a higher-concentration gas solution can be generated and the generation amount of fine bubbles can be increased.

According to a fifth feature of the microbubble generator according to the present invention, in addition to any of the first to fourth features described above, undissolved gas is separated from the liquid discharged from the discharge port of the liquid pump. Equipped with a gas-liquid separator that discharges
The gas-liquid separation part is configured by a folded flow path that extends upward from the discharge port of the liquid pump and then turns downward.

According to the fifth characteristic configuration, by providing the gas-liquid separator, the undissolved gas discharged from the liquid pump can be separated from the liquid and discharged, so that the undissolved gas is a large bubble. Can be prevented from being discharged into the tank through the decompression section.
Furthermore, by configuring such a gas-liquid separation unit with the folded flow path that is directly connected to the discharge port of the liquid pump, undissolved gas discharged from the discharge port of the liquid pump was also discharged. Along with the flow of the liquid, the folded flow path is well raised and stays in the upper end space through the rising flow path leading to the discharge port. Then, the undissolved gas is discharged well from the upper end space, and the liquid excluding the undissolved gas is well lowered through the descending flow path leading to the decompression section in the folded flow path. In the folded flow path as the gas-liquid separator, the undissolved gas can be satisfactorily separated from the liquid.

An embodiment of a fine bubble generator according to the present invention will be described with reference to the drawings.
A fine bubble generating device 50 shown in FIG. 1 takes in bathtub water W (an example of liquid) stored in a bathtub 1 (an example of a tank) into a circulation path 4 through an inflow port 2, and circulates through the circulation path 4. In such a form that the bathtub water W after being supplied into the bathtub 1 through the outlet 3, the fine bubbles B made of air A (an example of gas) are generated in the bathtub water W stored in the bathtub 1. It is configured.

  That is, the microbubble generator 50 includes a water pump 10 (an example of a liquid pump), an air introduction path 5 (an example of a gas introduction unit), and a pressure reducing valve 8 (an example of a decompression unit) that are described later. Is arranged in the circulation path 4 and further includes a control device 30 capable of controlling the operation of the water pump 10 and the pressure reducing valve 8 and the like.

The water pump 10 is configured to increase the pressure of the bathtub water W sucked from the suction port 11 by the centrifugal action accompanying the rotation of the impeller 13 and discharge the water from the discharge port 12. The vortex pump is configured as a vortex pump capable of stirring well while increasing the pressure of the bath water W by the vortex generated between the impeller 13 and the passage 14 formed on the outer periphery thereof.
The water pump 10 is configured to rotationally drive the impeller 13 using a driving motor 15 that is a DC motor as a driving source, and adjusts the voltage applied by the power supply circuit 17 of the driving motor 15. Thus, the output can be adjusted.

Further, a rotation sensor 16 that outputs a signal along with the rotation of the water pump 10 and an ammeter 18 that measures a current value supplied from the power supply circuit 17 to the driving motor 15 are provided.
And the control apparatus 30 is comprised so that it may function as the state detection means 31 which detects the state of the water pump 10 using the output of the said rotation sensor 16 or the said ammeter 18. FIG.
That is, the state detection means 31 is configured to detect the rotation speed of the water pump 10 as the state of the water pump 10 in a form in which the output of the rotation sensor 16 is counted every unit time. Further, the state detecting means 31 utilizes the fact that the output of the ammeter 18, that is, the current value corresponds to the rotational torque of the water pump 10, and rotates the water pump 10 from the output of the ammeter 18. Torque is detected as the state of the water pump 10.

  The air introduction path 5 serves as an air introduction section that introduces air A into the bathtub water W sucked into the suction port 11 of the water pump 10, that is, the bathtub water W that circulates upstream of the water pump 10 in the circulation path 4. Furthermore, the air introduction valve 6 (gas introduction amount adjustment) capable of adjusting the introduction amount of air A to the bathtub water W (hereinafter referred to as “air introduction amount”) is provided in the air introduction path 5. An example of means) is provided.

The pressure-reducing valve 8 functions as a pressure-reducing unit that depressurizes the bathtub water W discharged from the water pump 10 and supplies the water into the bathtub 1. The pressure difference of the primary side (inlet side) pressure with respect to the secondary side (outlet side) pressure of the pressure reducing valve 8, that is, the outlet 3 side of the bathtub 1 is adjusted. The differential pressure of the pressure on the discharge port 12 side of the water pump 10 with respect to the pressure can be changed.
The state detection means 31 of the control device 30 is configured to detect the primary pressure of the pressure reducing valve 8 by a pressure sensor 7 provided on the inlet side of the pressure reducing valve 8 in the circulation path 4.

  The control device 30 is configured to increase the pressure of the bath water W into which the air A has been introduced by the air introduction path 5 by the water pump 10, and then reduce the pressure by the pressure reducing valve 8 and supply the water into the bathtub 1. And it is comprised so that it may function as the control means 32 which can perform the fine bubble generation | occurrence | production operation | movement which generates the fine bubble B in the bathtub water W stored in the bathtub 1. FIG.

That is, the control means 32 is supplied into the bathtub 1 by operating the water pump 10 to reduce the opening of the pressure reducing valve 8, as will be described in detail later, when executing the fine bubble generation operation. The pressure in the bathtub water W is reduced, and the air A is introduced into the bathtub water W that circulates in the circulation path 4 by opening the opening of the air introduction valve 6.
Then, by this microbubble generation operation, the bathtub water W flowing through the circulation path 4 flows into the passage 14 of the water pump 10 through the suction port 11 together with the air A introduced by the air introduction path 5. In the passage 14, the mixture of the air A and the bathtub water W is boosted and stirred by the vortex generated by the rotation of the impeller 13, so that a relatively large amount of the air A is generated with respect to the bathtub water W. The dissolved air-dissolved water W ′ is generated, and the air-dissolved water W ′ is discharged from the passage 14 through the discharge port 12. Then, the air-dissolved water W ′ is decompressed by the decompression valve 8 and is supplied into the bathtub 1, so that air A is precipitated as fine bubbles B from the air-dissolved water W ′ after the decompression, The fine bubbles B are supplied to the bathtub water W stored in the bathtub 1.

  Further, in the fine bubble generator 50, a gas-liquid separation unit 20 that separates and discharges undissolved air A from the air-dissolved water W ′ discharged from the discharge port 12 of the water pump 10 is provided in the discharge port 12. They are directly connected and integrated with the water pump 10.

Further, the gas-liquid separation unit 20 is constituted by folded flow channels 21, 22, 23 that extend upward from the discharge port 12 of the water pump 10 and then fold downward. That is, the folded flow channels 21, 22, and 23 are a space formed in the rising channel 21 connected to the discharge port 12 and extending upward from the discharge port 12 and the upper end portion of the rising channel 21. The upper end space 22 includes a certain upper end space 22 and a descending flow path 23 connected to the upper end space 22 and extending downward from the upper end space 22.
Furthermore, in the upper end space 22, the discharge path 26 that opens the upper surface of the upper end space 22 to the atmosphere, the water level sensor 24 that detects the water level in the upper end space 22, and the water level detected by the water level sensor 24 are constant. An air discharge amount adjustment valve 25 for adjusting the amount of air A discharged through the discharge passage 26 (hereinafter referred to as “air discharge amount”) is provided.

  In the gas-liquid separator 20, the undissolved air A discharged from the discharge port 12 of the water pump 10 flows into the upper end through the ascending flow path 21 along with the flow of the discharged air-dissolved water W ′. It will rise well and stay in the space 22. Furthermore, the undissolved air A staying in the upper end space 22 is discharged well through the discharge path 26 connected to the upper surface of the upper end space 22 so that the water level of the upper end space 22 is constant, The air-dissolved water W ′ excluding the air A of the air drops well through the descending passage 23, and as a result, the air-dissolving water 21 ′ as the gas-liquid separation unit 20 is satisfactorily dissolved in the air. The undissolved air A is well separated from the water W ′.

  In the fine bubble generator 50 described so far, when the dissolved oxygen concentration of the air-dissolved water W ′ discharged from the discharge port 12 of the water pump 10 under a certain condition is measured, as shown in FIG. It was confirmed that the solubility of the air A in the bathtub water W in the water pump 10 increased because the dissolved oxygen concentration increased as the amount of air introduced into the bathtub water W by 5 increased. Then, if the air introduction amount is increased so that the dissolved oxygen concentration becomes 13 mg / L or higher, the air A is sufficient so that a sufficient amount of fine bubbles B are generated in the bathtub 1. A dissolved high-concentration air-dissolved water W ′ can be generated.

  However, if the air introduction amount is increased too much in this way, a gas lock phenomenon may occur in the water pump 10.

  Therefore, the control means 32 uses the outputs of the rotation sensor 16 and the ammeter 18 to detect the state in the fine bubble generation operation in order to stably generate a sufficient amount of fine bubbles B in the entire bathtub 1. An air introduction amount setting process for setting the amount of air introduced into the bathtub water W by the air introduction valve 6 so that the rotational speed and the rotational torque of the water pump 10 detected by the means 31 are maintained within the target range. An example of processing) is performed.

That is, the control means 32 performs the air introduction amount setting process, thereby maintaining the rotation speed and rotation torque of the water pump 10 detected by the state detection means 31 within the target range, thereby causing a gas lock phenomenon. In the water pump 10, as much air A as possible is introduced into the bathtub water W circulated through the circulation path 4 by the air introduction path 5 while maintaining a stable state capable of suppressing stoppage or breakage of the water pump 10 due to The bath water W is stably brought into contact with a large amount of air A to generate an air solution W ′ having a concentration as high as possible.
Therefore, by decompressing the high-concentration air solution W ′ by the pressure reducing valve 8 and supplying it into the bathtub 1, a sufficient amount of fine bubbles B in the bathtub water W stored in the bathtub 1 is stabilized. Will occur.

  Further, the control means 32 is configured to execute the pump output setting process and the differential pressure setting process before executing the air introduction amount setting process in the fine bubble generation operation. The details of each process in the operation will be described below based on FIGS. 3 to 6 together with the process flow of the fine bubble generation operation.

[Microbubble generation operation]
As shown in FIG. 3, the control means 32 starts the fine bubble operation when an operation start command is input by a user operating an operation start button (not shown) or the like (step # 01).

  And in this fine bubble operation, first, while setting the opening degree Va of the air introduction valve 6 to a fully closed state, the introduction of the air A to the bathtub water W by the air introduction path 5 is stopped, The opening degree Vo of the pressure reducing valve 8 is set to be fully open, and so-called initial setting is performed to bring the pressure reducing valve 8 into a non-depressurized state where pressure reduction is stopped (step # 02).

  Next, the operation of the water pump 10 is started while maintaining the non-air introduction state and the non-depressurization state (step # 03), and the bath water W is circulated through the circulation path 4, and the pump output setting described later is performed. By executing the process (an example of the pump output setting process) (step # 04), the output of the water pump 10 is set to an appropriate value.

  Next, while maintaining the non-air introduction state, the pressure reducing valve 8 starts to be depressurized by reducing the opening of the pressure reducing valve 8 (step # 05). By executing step # 06), the differential pressure of the pressure reducing valve 8 is set to an appropriate value.

  Then, after executing the pump output setting process and the differential pressure setting process to set the output of the water pump 10 and the differential pressure of the pressure reducing valve 8, the rotational speed N of the water pump 10 at that time is rotated before adjustment. After storing as the speed n1 (step # 07), the air A to the bathtub water W that circulates the circulation path 4 from the air introduction path 5 by the suction force of the water pump 10 by expanding the opening of the air introduction valve 6 As an air introduction state for starting the introduction of air (step # 08), a first air introduction amount setting process (an example of an air introduction amount setting process) (step # 09) described later is executed (step # 09) and stored in the bathtub 1 A sufficient amount of fine bubbles B are stably generated in the bath water W.

  Further, after executing the first air introduction amount setting process, the rotational speed N of the water pump 10 at that time is again stored as the pre-adjustment rotational speed n1 (step # 10), and then a second air introduction amount setting to be described later is performed. Processing (an example of air introduction amount setting processing) (step # 11) is performed, the air introduction amount is shifted to the increasing side, and as many fine bubbles B as possible are stabilized in the bathtub water W stored in the bathtub 1. To generate.

  Then, while determining whether or not an operation stop command has been input by an operation of an operation stop button (not shown) or the like by the user (step # 12), a fixed waiting time (for example, 2 seconds) is passed in between. (Step # 13) The second air introduction amount setting process in Step # 11 is repeatedly executed. If it is determined in Step # 12 that the operation stop command has been input, the fine bubble generation operation is terminated.

[Pump output setting processing]
As described above, the control means 32 starts the operation of the water pump 10 while maintaining the non-air introduction state and the non-depressurization state in the fine bubble generation operation, and then sets the pump output in the step # 04. Details of the pump output setting process will be described below.

The control means 32 uses the rotation speed N and the rotation torque I of the water pump 10 sequentially detected by the state detection means 31 based on the outputs of the rotation sensor 16 and the ammeter 18 in the pump output setting process. The applied voltage Vp of the driving motor 15 that drives the motor is set.
That is, as shown in FIG. 4, when the rotational speed N does not fall within the target range below the rotational speed nmax / b that is smaller than the target rotational speed range upper limit value nmax by a predetermined ratio 1 / b (step # 04-2). Alternatively, when the rotational torque I is not within the target range equal to or less than the target rotational torque range upper limit value imax1 (step # 04-3), the applied voltage Vp is adjusted to the lower side for each predetermined adjustment width Δvp. By doing this (step # 04-5), the rotational speed N and the rotational torque I are reduced. Here, b is a value of 1 or more. For example, in the fine bubble generating apparatus 50, the rate of increase of the rotational speed N after the start of air introduction relative to the rotational speed N before the start of air introduction by the air introduction valve 6 is increased. It is set as an experience value according to. Here, the target rotation speed range upper limit value nmax is a value set as an upper limit value of the rotation speed at which the water pump 10 can operate stably. Further, the target rotational torque range upper limit value imax1 is a value set as the upper limit value of the rotational torque at which the water pump 10 can operate stably in the non-air introduction state where the air A is not introduced.
On the other hand, when the rotational torque I does not fall within the target range equal to or greater than the target rotational torque range upper limit value imax1 (step # 04-6), the control means 32 increases the applied voltage Vp for each predetermined adjustment width Δvp. By adjusting to the increasing side (step # 04-1), the rotational torque I is increased.
That is, in the pump output setting process, the control means 31 determines that the rotation speed N of the water pump 10 is within the target range of the rotation speed nmax / b and the rotation torque I of the water pump 10 is the target rotation. The applied voltage Vp of the water pump 10 is adjusted so that the torque range upper limit value imax1.

  In step # 04-5, when adjusting the applied voltage Vp to the decreasing side, if the Vp falls below the lower limit value vpmin of the adjustable range (step # 04-4), or In adjusting the applied voltage Vp to the increasing side in 04-1, if the Vp exceeds the upper limit value vpmax of the adjustable range (step # 04-7), it is assumed that some abnormality has occurred. The water pump 10 is stopped, and an abnormal stop such as outputting an alarm is executed (step # 04-8).

[Differential pressure setting process]
As described above, the control means 32 starts the pressure reduction by the pressure reducing valve 8 by reducing the opening of the pressure reducing valve 8 as the pressure reducing state while maintaining the non-air introduction state in the fine bubble generating operation. Later, in step # 06, the differential pressure setting process is executed. Details of the differential pressure setting process will be described below.

In the differential pressure setting process, the control means 32 uses the primary pressure P of the pressure reducing valve 8 successively detected by the state detecting means 31 based on the output from the pressure sensor 7 to set the opening Vo of the pressure reducing valve 8. Set.
That is, as shown in FIG. 5, when the primary pressure P of the pressure reducing valve 8 does not fall within the target range below the target pressure range upper limit pmax (step # 06-6), the pressure reducing valve 8 is opened. The pressure P is decreased by adjusting the degree Vo to the increasing side every predetermined adjustment width Δvo (step # 06-8).
On the other hand, when the primary pressure P of the pressure reducing valve 8 does not fall within the target range equal to or higher than the target pressure range lower limit value pmin (step # 06-9), the control means 32 opens the opening of the pressure reducing valve 8. The pressure P is increased by adjusting Vo to the decreasing side every predetermined adjustment width Δvo (step # 06-1).
That is, in the differential pressure setting process, the control means 31 opens the opening of the pressure reducing valve 8 so that the primary pressure P of the pressure reducing valve 8 is within a target range not less than the lower limit pmin and not more than the upper limit pmax. Adjust Vo.

  Further, at the same time when the opening degree Vo of the pressure reducing valve 8 is adjusted by the step # 06-1 or the step # 06-5, the rotational speed N is higher than the target rotational speed range upper limit value nmax by a predetermined ratio 1 / b. If the rotational speed I does not fall within the target range below the low rotational speed nmax / b (step # 06-2), or the rotational torque I does not fall within the target range below the target rotational torque range upper limit value imax1 (step # 06-3). ), The applied voltage Vp is adjusted to the lower side for each predetermined adjustment width Δvp (step # 06-5), thereby reducing the rotational speed N and the rotational torque I.

  In step # 06-8, when the opening Vo of the pressure reducing valve 8 is adjusted to increase, when the Vo exceeds the upper limit value vomax of the adjustable range (step # 06-7), or In adjusting the opening degree Vo of the pressure reducing valve 8 to the decreasing side in the above step # 06-1, if the Vo falls below the lower limit value vomin of the adjustable range (step # 06-10), or In adjusting the applied voltage Vp to the decreasing side in the above step # 06-5, if the Vp falls below the lower limit value vpmin of the adjustable range (step # 06-4), some abnormality has occurred. As a matter of course, the water pump 10 is stopped and an abnormal stop such as outputting an alarm is executed (step # 06-11).

[First air introduction amount setting process]
As described above, the control means 32 stores the rotational speed N of the water pump 10 at that time as the pre-adjustment rotational speed n1 as the reduced pressure state and the air introduction state in the fine bubble generation operation. In step # 09, the first air introduction amount setting process is executed. Details of the first air introduction amount setting process will be described below.

In the first air introduction amount setting process, the control means 32 uses the rotation speed N of the water pump 10 sequentially detected by the state detection means 31 based on the output of the rotation sensor 16 to open the opening of the air introduction valve 6. Va is set.
That is, as shown in FIG. 6, when the rotational speed N does not fall within the target range below the rotational speed n1 · b that is a predetermined rate b larger than the rotational speed n1 before adjustment (step # 09-9), The rotational speed N is reduced by adjusting the opening degree Va of the air introduction valve 6 to the decreasing side every predetermined adjustment width Δva (step # 09-11).

On the other hand, when the rotational speed N does not fall within the target range of the rotational speed n1 · a greater than the rotational speed n1 before adjustment by a predetermined ratio a (step # 09-12), The rotational speed N is increased by adjusting the opening degree Va of the air introduction valve 6 to the increasing side every predetermined adjustment width Δva (step # 09-1). Here, a and b are one or more values having a relationship of a <b. For example, in the fine bubble generating device 50, air introduction with respect to the rotation speed N before the air introduction valve 6 starts air introduction is performed. It is set as an empirical value corresponding to the increasing rate of the rotational speed N after the start.
That is, in the first air introduction amount setting process, the control means 31 controls the air introduction valve 6 so that the rotation speed is within a target range of the lower limit value n1 · a and the upper limit value n1 · b. The opening degree Va is adjusted.

Further, at the same time as adjusting the opening degree Va of the air introduction valve 6 by the step # 09-1 or the step # 09-11, the applied voltage Vp of the water pump 10 is set in substantially the same manner as the pump output setting process described above. adjust.
That is, when the rotational speed N is not within the target range below the target rotational speed range upper limit value nmax (step # 09-2), or the target range where the rotational torque I is below the target rotational torque range upper limit value imax2 If it is not within (step # 09-3), the applied voltage Vp is adjusted to the lower side for each predetermined adjustment width Δvp (step # 09-5), so that the rotational speed N and the rotational torque I are adjusted. Reduce. Here, the target rotational torque range upper limit value imax2 is a value set as the upper limit value of the rotational torque at which the water pump 10 can stably operate in the air introduction state where the air A is introduced. It is set to a value smaller than the target rotational torque range upper limit value imax1 in the non-air introduction state.
On the other hand, when the rotation speed N does not fall within the target range equal to or greater than the target rotation speed range lower limit value nmin (step # 09-6), the control means 32 sets the applied voltage Vp for each predetermined adjustment width Δvp. The rotational speed N is increased by adjusting to the increasing side (step # 09-8).
That is, the control means 31 is configured such that the rotational speed N of the water pump 10 is in a range not less than the lower limit value nmin and not more than the upper limit value nmax, and the rotational torque I of the water pump 10 is the target rotational torque range upper limit value imax2. The applied voltage Vp of the water pump 10 is adjusted so as to be as follows.

  In step # 09-11, when the opening Va of the air introduction valve 6 is adjusted to the decreasing side, when the Va falls below the lower limit value vamin of the adjustable range (step # 09-10), Alternatively, when the opening Va of the air introduction valve 6 is adjusted to increase in step # 09-1, the Va exceeds the upper limit value vamax of the adjustable range (step # 09-13). Alternatively, when adjusting the applied voltage Vp to the decreasing side in step # 09-5, if the Vp falls below the lower limit value vpmin of the adjustable range (step # 09-4), or the above step # In adjusting the applied voltage Vp to increase in 09-8, the Vp exceeds the upper limit value vpmax of the adjustable range (step #). 9-7) In this case, assuming that some abnormality has occurred, stops the water pump 10, to execute the abnormality stop, such as outputting an alarm (step # 09-14).

[Second air introduction amount setting process]
As described above, the control means 32 stores the rotational speed N of the water pump 10 at that time as the rotational speed n1 before adjustment after executing the first air introduction amount setting process in the fine bubble generation operation. In step # 11, the second air introduction amount setting process is executed. Details of the second air introduction amount setting process will be described below.

When the opening degree Va of the air introduction valve 6 is less than the upper limit value vamax of the adjustable range in the second air introduction amount setting process (step # 11-1), the control means 32 performs the air introduction amount. In order to shift the process to the increasing side, the following processes of Step # 11-2 to Step # 11-6 are appropriately executed.
That is, in the state where the opening degree Va of the air introduction valve 6 is once increased by a predetermined adjustment width Δva ′ (step # 11-2), the rotation speed N of the water pump 10 is equal to or less than the target rotation speed range upper limit value nmax. (Step # 11-3), whether the rotational torque I of the water pump 10 is equal to or less than the target rotational torque range upper limit value imax2 (step # 11-4), and further, the rotational speed N of the water pump 10 It is determined whether or not the increase width N-n1 with respect to the pre-adjustment rotational speed n1 is equal to or smaller than a predetermined allowable increase width Δn (step # 11-5).

  If any of the determination processes is “no”, that is, the rotational speed N is not equal to or lower than the target rotational speed range upper limit value nmax, or the rotational torque I is not equal to or lower than the target rotational torque range upper limit value imax2. Alternatively, if the increase width N-n1 is not less than or equal to the allowable increase width Δn, the opening Va of the air introduction valve 6 once increased in step # 11-2 is immediately doubled by the adjustment width Δva ′. Is reduced by a decrease width of 2 · Δva ′ (step # 11-7) to avoid excessive air introduction.

  On the other hand, if “yes” in each determination process, that is, the rotational speed N is equal to or lower than the target rotational speed range upper limit value nmax, and the rotational torque I is equal to or lower than the target rotational torque range upper limit value imax2. When the increase width N-n1 is equal to or less than the allowable increase width Δn, the second air introduction is performed while maintaining the state in which the opening degree Va of the air introduction valve 6 is increased and the air introduction amount is increased. The amount setting process ends. And since this 2nd air introduction amount setting process is repeatedly performed until it stops the fine bubble generation | occurrence | production operation | movement, the said air introduction amount will transfer to the increase side, and the air with respect to the bathtub water W in the water pump 10 The solubility of A is increased, and the amount of fine bubbles B generated in the bathtub 1 shifts to the increasing side.

  Further, when adjusting the opening degree Va of the air introduction valve 6 to the decreasing side in the step # 11-7, when the Va is below the lower limit value vamin of the adjustable range (step # 11-6). Assuming that some kind of abnormality has occurred, the water pump 10 is stopped and an abnormal stop such as outputting an alarm is executed (step # 11-8).

[Another embodiment]
(1) In the said embodiment, although the fine bubble generator 50 which concerns on this invention was comprised so that the fine bubble B which consists of the air A might be generated in the bathtub water W stored in the bathtub 1, the said bathtub As a separate tank, the bath water is made another liquid, the air is made another gas, etc. Can be appropriately modified.
Moreover, as said gas, you may utilize the carbon dioxide contained in the combustion exhaust gas of the water heater which heats bathtub water other than the said air, for example.

(2) In the above embodiment, the water pump 10 is configured as a vortex pump. Separately, the water pump is a centrifugal pump different from the vortex pump, that is, the liquid sucked from the suction port is rotated by the impeller. The liquid pump may be configured to increase the pressure by the centrifugal action accompanying the discharge and discharge from the discharge port.

(3) In the above-described embodiment, the pressure reducing part that depressurizes the bathtub water W discharged from the water pump 10 and supplies it into the bathtub 1 is configured as the pressure reducing valve 8, but the pressure reducing part is another form such as an orifice. You may comprise.

(4) In the above embodiment, the gas-liquid separation unit 20 that separates and discharges the undissolved air A from the bathtub water W (air-dissolved water W ′) discharged from the discharge port 12 of the water pump 10 is raised. The flow path 21, the upper end space 22 and the descending flow path 23 are configured as a folded flow path. Separately, the gas-liquid separation unit is formed with a liquid inlet and outlet on the lower surface, and a gas outlet on the upper surface. You may comprise with another forms, such as a tank in which it was formed.
Further, in the case where the undissolved air A may be supplied into the bathtub 1 as a large bubble, the gas-liquid separation unit 20 may be omitted.

(5) In the above embodiment, the air introduction valve 6 capable of adjusting the air introduction amount by the air introduction passage 5 is provided. However, an air pump is provided in the air introduction passage, and the blast amount of the air pump is adjusted. You may comprise so that the air introduction amount may be adjusted.

  The fine bubble generating apparatus according to the present invention generates a gas dissolved liquid by increasing the pressure and further stirring the liquid into which the gas has been introduced by the gas introducing section, and reducing the pressure of the gas dissolved liquid by the decompressing section. When microbubbles are generated in the liquid stored in the tank by supplying it into the tank, it can be effectively used as a microbubble generator that stably generates a sufficient amount of microbubbles throughout the tank. .

Schematic configuration diagram of microbubble generator Graph showing the relationship between the amount of air introduced and the dissolved oxygen concentration Processing flow diagram of microbubble generation operation Process flow diagram of pump output setting process Process flow diagram of differential pressure setting process Process flow diagram of first air introduction amount setting process Process flow diagram of second air introduction amount setting process

Explanation of symbols

1: Bathtub (an example of a tank)
5: Air introduction path (an example of a gas introduction part)
6: Air introduction valve (an example of gas introduction amount adjusting means)
7: Pressure sensor 8: Pressure reducing valve (an example of a pressure reducing unit)
10: Water pump (an example of a liquid pump)
11: Suction port 12: Discharge port 13: Impeller 16: Rotation sensor 18: Ammeters 21, 22, 23: Folding channel 26: Discharge channel 31: State detection unit 32: Control unit 50: Fine bubble generator A: Air (example of gas)
B: Fine bubbles W: Bath water (an example of liquid)
W ': Air dissolved water (gas dissolved solution)

Claims (5)

A liquid pump that boosts the liquid sucked from the suction port by a centrifugal action accompanying the rotation of the impeller and discharges the liquid from the discharge port; a gas introduction unit that introduces gas into the liquid sucked into the suction port of the liquid pump; A pressure reducing unit that depressurizes the liquid discharged from the liquid pump and supplies the liquid into the tank;
After the liquid into which the gas is introduced by the gas introduction unit is pressurized by the liquid pump, the pressure is reduced by the decompression unit and supplied into the tank, so that fine bubbles are generated in the liquid stored in the tank. A fine bubble generating device including a control means capable of executing a fine bubble generating operation to be generated,
A gas introduction amount adjusting means capable of adjusting a gas introduction amount by the gas introduction unit;
A state detecting means for detecting the state of the liquid pump,
Said control means sets the gas introduction amount to the liquid the in fine bubble generating operation by the gas introduction amount adjusting means so as to maintain the state of the liquid pump detected by the state detecting means within the target range Configured to execute the gas introduction amount setting process ,
In the microbubble generation operation, the control means starts the operation of the liquid pump in a state where the gas introduction by the gas introduction unit and the pressure reduction of the liquid by the pressure reduction unit are stopped, and the output of the liquid pump is Execute pump output setting processing to set the rotational torque to be the target rotational torque range upper limit value,
Next, a differential pressure setting process for starting the pressure reduction of the liquid by the pressure reducing unit in a state where the introduction of the gas by the gas introducing unit is stopped and setting the primary pressure of the pressure reducing unit within a target range,
Next, the rotational speed of the liquid pump at the present time is set as the rotational speed before adjustment, and when the rotational speed of the liquid pump is smaller than the target rotational speed lower limit value that is larger than the rotational speed before adjustment, the gas introduction amount is increased. The rotation speed of the liquid pump is increased, and when the rotation speed of the liquid pump is larger than the target rotation speed upper limit value, control is performed to decrease the rotation speed of the liquid pump by decreasing the gas introduction amount. And performing the first gas introduction amount setting process as the gas introduction amount setting process for setting the gas introduction amount to a value larger than the target gas introduction amount lower limit value and smaller than the target gas introduction amount upper limit value,
Next, when the gas introduction amount introduced by the gas introduction part is smaller than the target gas introduction amount upper limit value, the second gas introduction amount setting as the gas introduction amount setting process for shifting the gas introduction amount to the increase side A fine bubble generator that performs processing .   The microbubble generator according to claim 1, wherein the tank is a bathtub, the liquid is bathtub water, and the gas is air. The fine bubble generating device according to claim 1 or 2 , wherein the state detection unit detects a state of a rotational speed and a rotational torque of the liquid pump as a state of the liquid pump . The microbubble generator according to any one of claims 1 to 3 , wherein the liquid pump is a vortex pump . A gas-liquid separator that separates and discharges undissolved gas from the liquid discharged from the discharge port of the liquid pump;
The microbubble generator according to any one of claims 1 to 4 , wherein the gas-liquid separator is configured by a folded flow path that extends upward from a discharge port of the liquid pump and then turns downward .

Images