JP2000157854A - Method and apparatus for mixing gas and liquid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To carry out smoothly gas and liquid mixing operation by adopting a measure for removing effectively a 'gas accumulation' to be generated in a turbine pump in a gas and liquid mixing process. SOLUTION: In a gas and liquid mixing process wherein a gas 19 to be fed from a gas manufacturing apparatus 12, and a liquid 9 to be fed from a liquid tank 8 are forced to be mixed by using a turbine pump 10, subsequently after gas feed stop for stopping feed of gas to the turbine pump 10 from the gas manufacturing apparatus 12, and discharged liquid return (by a discharged liquid reflux channel 15) for returning a discharged liquid 24 from the turbine pump 10 to the liquid tank, or outflow to a channel 14 to be used, the turbine pump 10 is changed to low speed operation by a rotation controller 11, and a gas storage 20 in the turbine pump 10 is removed by introduction of the liquid from the liquid tank 8 or force fit of liquid 9 from the liquid tank 8 into the turbine pump 10 via a pump exclusively used for expelling gas.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a gas-liquid mixing method and apparatus for mixing and dissolving a gas such as ozone in a liquid such as water. More specifically, in a gas-liquid mixing pump, particularly in a gas-liquid mixing technology using a vertical multi-stage turbine pump, a so-called `` gas pool '' that is generated and stays in the gas-liquid mixing pump during the gas-liquid mixing process. The present invention relates to a gas-liquid mixing method and a device which solve the problem that a restart of a gas-liquid mixing pump becomes impossible.

[0002]

2. Description of the Related Art Heretofore, as a method of mixing a hardly soluble gas such as ozone with a liquid such as water, a gas-liquid mixing pump, especially a vertical multistage turbine pump, is used. A technique for mixing gas and liquid by energy is generally known.

Specifically, a gas and a liquid to be mixed are introduced into the gas-liquid mixing pump from the suction port of the gas-liquid mixing pump by using the suction force of the gas-liquid mixing pump itself. In this method, gas and liquid are mixed by applying pressure and shearing.

[0004]

However, in this conventional gas-liquid mixing technology, when a gas-liquid mixing pump, particularly a vertical multistage turbine pump is used, a difference in specific gravity between gas and liquid is caused. Therefore, there is a problem that "gas pool" is easily generated in the pump.

That is, when the gas-liquid mixing pump is restarted after its operation is stopped, the "gas pool" generated in the pump makes it impossible to restart the gas-liquid mixing pump.

Further, even when the restart is not possible, a problem that the "gas pool" is discharged from the gas-liquid mixing pump at the time of restart and induces a water hammer in the subsequent piping. There was also.

[0007] Further, using a gas vent hole (for example, a hole for opening and closing with a screw to release gas in the pump, indicated by reference numeral 23 in FIG. 1) provided as a standard feature in the gas-liquid mixing pump, In the past, the method of discharging "dams" has been generally adopted, but in this method, the liquid is scattered around the gas-liquid mixing pump, so that obstacles to the electric components disposed around and corrosion of the components occur. There was a problem that the gas removal efficiency was poor.

Accordingly, the present invention relates to a gas-liquid mixing technique using a gas-liquid mixing pump, particularly a vertical multistage turbine pump, in which a "gas pool" generated and stays in the gas-liquid mixing pump during the gas-liquid mixing process. It is an object of the present invention to provide a gas-liquid mixing method and apparatus which can take a countermeasure to effectively remove the gas and perform a gas-liquid mixing operation smoothly.

[0009]

In order to achieve the above object, the present invention employs the following means. In the gas-liquid mixing method according to the present invention, the gas supplied from the gas producing apparatus and the liquid supplied from the liquid tank are introduced into the gas-liquid mixing pump,
In a gas-liquid mixing method for pressurizing and mixing gas-liquid, a gas supply stopping step of stopping gas supply from the gas production device to the gas-liquid mixing pump, and a discharge liquid discharge for discharging a liquid discharged from the gas-liquid mixing pump Subsequent to the step, the gas-liquid mixing pump is switched to low-speed operation, and a gas introduction step in which the liquid is introduced from the liquid tank to the gas-liquid mixing pump discharges a gas pool remaining in the gas-liquid mixing pump. A gas-liquid mixing method is adopted.

Further, in the gas-liquid mixing apparatus according to the present invention, the gas supplied from the gas producing apparatus and the liquid supplied from the liquid tank are introduced into a turbine pump, and the gas-liquid mixing apparatus pressurizes and mixes the gas and liquid. In the above, gas supply stop means for stopping the supply of gas supplied from the gas production apparatus to the turbine pump, discharge liquid discharge means for discharging the liquid discharged from the turbine pump, and rotation of the turbine pump A gas-liquid mixing device including rotation control means for reducing the speed and liquid introduction means for introducing the liquid from the liquid tank to the gas-liquid mixing pump is employed.

In these means, a so-called "gas pool" generated and accumulated in the gas-liquid mixing pump during the gas-liquid mixing process is removed from the liquid tank by the gas-liquid mixing pump set from the rated operation to the low-speed operation. With the introduced liquid (liquid containing no gas), without shearing the "gas pool",
Efficiently discharges together with the discharged liquid outside the gas-liquid mixing pump while maintaining the volume. Accordingly, when the gas-liquid mixing pump is restarted after the operation is stopped, the “gas pool” generated in the pump does not stay in the gas-liquid mixing pump. The problem of inhibition is eliminated. In addition, even if it is not possible to make restart impossible, problems such as "water pool" being discharged from the gas-liquid mixing pump at restart and causing a water hammer in the subsequent piping etc. Is also gone.

Here, in the liquid introducing step of introducing a liquid from the liquid tank to the gas-liquid mixing pump in the gas-liquid mixing method, or in the liquid introducing means, the liquid is transferred from the liquid tank to the gas pump via a pump dedicated to gas purge. Means for press-fitting into a gas-liquid mixing pump can be adopted.

In this means, since the liquid is pushed into the gas-liquid mixing pump via the pump for exclusive use of gas, the "gas pool" in the gas-liquid mixing pump is forcibly and efficiently discharged out of the gas-liquid mixing pump. It becomes possible.

In the case where the gas-liquid mixing pump is a vertical multistage turbine pump,
This is a particularly effective means since "gas pools" are easily generated.

Furthermore, as a discharge liquid discharging step or means for discharging the liquid (discharge liquid) discharged from the turbine pump, a step or means for returning the discharge liquid to the liquid tank can be appropriately adopted. If this is done, liquid that is not mixed with gas and liquid will continuously flow into the gas-liquid mixture utilization device (discharge)
Even if it is not possible to perform the treatment, the discharged liquid can be returned to the liquid tank via the discharged liquid return path, which is convenient, and the versatility of the gas-liquid mixing method or apparatus according to the present invention is convenient. Will spread.

[0016]

Next, a preferred embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a diagram schematically illustrating the configuration of a gas-liquid mixing device according to the present invention, and FIG.
FIG. 3 is a flowchart simply illustrating a procedure for discharging a “gas pool” from inside a turbine pump in a gas-liquid mixing process according to the present invention.

First, the configuration of the gas-liquid mixing device according to the present invention will be described with reference to FIG. The gas-liquid mixing device according to the present invention is manufactured by a gas manufacturing device 12 that can select an appropriate means such as a PSA type oxygen generator and an ozone generator using the oxygen, and is sequentially supplied into the pipe. A gas 19 (for example, oxygen or hardly soluble ozone, etc.) is supplied to a liquid 9 such as water supplied from a separately installed liquid tank 8 through a pipe through a negative pressure through an ejector (not shown). The gas-liquid mixing pump 10 is introduced into the gas-liquid mixing pump 10 (in this embodiment, a vertical multistage turbine pump is used), and the gas-liquid is mixed under pressure.

As described above, when a gas-liquid mixing pump, particularly a vertical multistage turbine pump 10 is used, the difference in specific gravity between the gas 19 and the liquid 9 causes The gas stays and a so-called gas pool 20 is generated. In particular, when a hardly soluble gas such as ozone is mixed with a liquid, the gas pool 2
0 easily occurs.

If the gas pool 20 is generated in the pump 10, if the turbine pump 10 is once stopped and then restarted, the gas pool 20 makes it impossible to restart the turbine pump 10. Will happen.

Further, even when the restart is not possible, the gas reservoir 20 is discharged from the turbine pump 10 at the time of restart, and the water hammer (also referred to as a water hammer action) in the subsequent piping. ) Can also occur.

Therefore, in order to solve these problems,
The gas-liquid mixing device according to the present invention includes gas supply stopping means for stopping the supply of the gas 19 supplied from the gas production device 12 to the turbine pump 10, and the liquid discharged from the turbine pump 10 into the liquid tank 8. Any discharge liquid discharging means for refluxing to the liquid or flowing out to the gas-liquid mixture utilization device 21, a rotation control means for lowering the rotation speed of the turbine pump 10, and sending liquid from the liquid tank to the turbine pump. And a liquid introduction means.

Here, the configuration of each of the above means will be specifically described. First, the gas supply stopping means includes a valve 6 provided in the middle of a pipe constituting a gas supply path 16 that communicates from the gas production device 12 to the turbine pump 10;
A valve 7 provided in the middle of a pipe constituting a gas discharge path 25 which branches off from the gas supply path 16 and opens to the outside
And is composed of

That is, when the valve 6 is opened and the valve 7 is closed, the gas 19 is supplied to the turbine pump 10. On the other hand, when the valve 6 is closed and the valve 7 is opened, the gas 19 is discharged to the outside without being supplied to the turbine pump 10, so that the gas supply to the turbine pump 10 is stopped. Will be. It is preferable that a so-called solenoid valve be used as the valve 6. The symbol M shown in FIG. 1 represents a motor for driving the valve.

Next, the discharge liquid recirculation means, which is one of the means for discharging the discharge liquid, is provided with a gas-liquid mixed solution utilization path 14.
And a discharge liquid recirculation path 15 branching from the use path 14 and heading toward the liquid tank 8.
And a valve 5 provided in the middle of a pipe constituting the discharge liquid recirculation path 15. That is, the valve 4
Is closed and the valve 5 is opened, the discharge liquid 24 can be returned to the liquid tank 8 via the discharge liquid return path 15.

On the other hand, as a means for discharging the discharge liquid 24, the use path 14 can be used as it is. That is,
Open the valve 4, close the valve 5, and set the turbine pump 1
The discharged liquid 24 discharged from 0 is passed through the utilization path 14,
For example, it is also possible to discharge the water to a water removal device or the like used for purification of pond water.

As means for discharging the discharge liquid 24, whether to use a means via the discharge liquid recirculation path 15 or to use the utilization path 14 as it is can be appropriately selected. This is limited to a case where the conditions for keeping the discharge liquid 24 flowing into the liquid mixture use device 21 are satisfied.

Next, the above-mentioned rotation control means of the turbine pump 10 is a device composed of an inverter 11 and the like connected to the turbine pump 10, and controls the rotation speed of the turbine pump 10 to reduce the high-speed rated operation. It is configured so that it can be appropriately selected up to low-speed operation.

When the turbine pump 10 is operated at a low speed,
The gas pool 20 stagnating inside due to the gas shearing force in the turbine pump 10 becoming weaker than during the rated operation,
Since the function of being able to be discharged to the outside while keeping the volume is exhibited, the gas pool 20 can be efficiently discharged.

Further, the above-mentioned liquid introducing means to the turbine pump 10 is in a state where the gas supply is stopped.
The condition that the valve 1 provided in the middle of the pipe constituting the liquid introduction path 18 communicating from the liquid tank 8 to the turbine pump 10 is opened to introduce only the liquid into the turbine pump 10 and to operate the turbine pump 10 at low speed Under the gas pool 2
0 is expelled (discharged) from the inside of the turbine pump 10.

Here, as the liquid introducing means for the turbine pump 10, means for separately providing a liquid press-in path 17 may be employed. That is, the liquid introduction path 1
A pipe is extended from the liquid tank 8 separately from the
Is provided with a liquid press-in passage 17 that communicates with a portion of the liquid introduction passage 18 subsequent to the disposition location, and a pump 13 (a gas (ie, gas A pump provided exclusively for removing the pool), a valve 2 formed in the liquid press-in passage 17 at a position behind the position where the pump 13 for degassing is disposed, and a liquid in front of the valve 2. Press-fitting path 1
A flow control path 22 branching from the flow path 7 and returning to the liquid tank 8, and a flow control valve 3 formed in the middle of the flow control path 22.
And are provided.

That is, when the means using the liquid press-in path 17 is provided, as the liquid introducing means, the valve 1 is opened, the valve 2 is closed, and the liquid 9 is introduced from the liquid tank 8 to the turbine pump 10. A means (normal liquid introducing means) for introducing through the passage 18 and the valve 1 are closed, the valve 2 is opened, and the liquid 9 pressurized by the pump 13 for degassing is forcibly pushed into the turbine pump 10. Any one of the means (press-fitting) (a liquid introducing means provided exclusively for degassing) can be appropriately selected.

The flow rate of the liquid 9 introduced into the turbine pump 10 via the liquid injection path 17 is controlled by the flow rate adjustment path 22.
It can be adjusted by the opening / closing amount of the flow control valve 3 formed on the way.

Based on the configuration of the gas-liquid mixing device according to the present invention described above, in the gas-liquid mixing method according to the present invention, referring to FIG. A procedure for discharging the gas from the turbine pump 10 will be described.

First, the opening / closing state of each valve and the operating state of the apparatus in a state where the gas-liquid mixing apparatus is operating will be briefly described. 1 (open) "), valve 2 (closed), valve 3 (closed), valve 4 (open), valve 5
(Closed), valve 6 (open), and valve 7 (closed).

Under the conditions of opening and closing these valves, the turbine pump 10 is operated at rated operation (about 1450
rpm), and from the liquid tank 8, the liquid introduction path 1
8 into the turbine pump 10 through the gas 1
9 has been introduced.

Then, the gas and the liquid are mixed and the turbine pump 1
The gas-liquid mixture discharged from 0 is introduced into a gas-liquid mixture utilization device 21 such as a water rot removal device (not shown) via a utilization path 14 and used.

In this case, when the operation of the gas-liquid mixing apparatus during the gas-liquid mixing operation is desired to be stopped from the operating state, the operation of the turbine pump 10 is stopped immediately, and the gas pool 20 is stored in the turbine pump 10. Is retained, so that the turbine pump 10 cannot be restarted.

Therefore, in order to avoid such a situation, the gas-liquid mixing method according to the present invention is devised to go through the following procedure. First, before stopping the operation of the turbine pump 10 that is performing the rated operation, the valve 7 is opened and the valve 6 is closed.

Then, the gas production of the gas production apparatus 12 is stopped. Specifically, for example, when the gas production device 12 is a device for producing ozone by taking in oxygen from environmental air, the power of the ozone generator portion (electrode) is turned off,
While releasing only oxygen from the valve 7 to the outside (do not release harmful ozone),
The gas 19 (oxygen, ozone, etc.) is prevented from flowing into the turbine pump 10 at all.

Subsequently, the valve 5 is opened and the valve 4 is opened.
Is closed, the discharge liquid 24 discharged from the turbine pump 10 is returned (refluxed) to the liquid tank 8 via the discharge liquid return path 15, and the flow of the discharge liquid 24 into the use path 14 is stopped.

As the discharge liquid discharging step or means for discharging the liquid (discharge liquid) discharged from the turbine pump 10 as described above, the discharge liquid is returned to the liquid tank 8 in addition to the means for directly flowing into the utilization path 14. In this case, the discharge liquid 24 not mixed with the gas-liquid cannot be flowed (discharged) into the gas-liquid mixed liquid utilizing device 21 for processing by adopting a process or means for performing the process. This is also very convenient because the discharged liquid 24 can be returned to the liquid tank 8 via the discharged liquid return path 15, and the versatility of the gas-liquid mixing method or apparatus according to the present invention can be expanded.

When the conditions on the side of the gas-liquid mixture use device 21 are satisfied, that is, when there is no problem even if the discharge liquid 24 in which the gas and liquid are not mixed continues to flow into the device 21 continuously. Alternatively, the discharged liquid 24 may flow into the use path 14 without passing through the discharged liquid recirculation path 15.

Here, at the same time as the above-mentioned liquid return operation (or discharge operation to the use path 14), the valve 1 is opened, and the liquid 9 is transferred from the liquid tank 8 through the liquid introduction path 18.
Is introduced into the turbine pump 10. At this time, while the valve 2 of the liquid press-in path 17 provided separately is opened,
The valve 1 and the valve 3 may be closed, and the liquid 9 may be forcibly pushed (press-fitted) into the turbine pump 10 exclusively through the degassing pump 13.

If the means for introducing the liquid through the pump 13 for degassing the liquid press-in path 17 is adopted as the liquid introduction method, the liquid 8 is forcibly pressed into the turbine pump 10. Efficiency is improved as a means for discharging the pool 20, which is more preferable.

Here, it is necessary to switch the turbine pump 10 from the rated operation to the low-speed operation by the inverter 11 before starting the operation of introducing (pushing) the liquid 9. The reason is that, by switching to low-speed operation and reducing the gas shearing force inside the turbine pump 10, the gas pool 20 can be discharged from the turbine pump 10 in a large volume without shearing. Because you can.

The operation of discharging the gas pool 20 at such a low speed operation is continued, and when the discharge of the gas pool 20 is completed,
The valve 1 is closed, or the operation of the pump 13 for degassing is stopped to stop the introduction of the liquid 9 into the pump 10. Then, after the valve opening / closing conditions are reset to valve 5 (closed), valve 4 (closed), valve 2 (closed), and valve 1 (open), the operation of the turbine pump 10 is stopped and restarted. A possible standby state. That is, the turbine pump 10
The gas pool 20 is discharged from the inside, and the liquid 9 is filled, so that the turbine pump 10 can be restarted.

[0047]

The effects of the invention disclosed by the present application will be described below. The present invention employs a method for efficiently discharging a "gas pool" generated in a turbine pump during a gas-liquid mixing process in a gas-liquid mixing technology using a turbine pump, particularly a vertical multistage turbine pump. Therefore, the gas-liquid mixing operation can be performed smoothly.

That is, when restarting is performed after the operation of the turbine pump is stopped, there is a problem that "gas pool" generated in the pump hinders restarting of the pump and makes restarting of the turbine pump impossible. Therefore, even if it is not possible to restart the system, it will not be possible to restart the system since the gas reservoir will be discharged from the turbine pump at the time of restart and will not cause a water hammer in the subsequent piping. Since it is easy to start and no water hammer is generated in the piping, the gas-liquid mixing operation can be performed smoothly.

[Brief description of the drawings]

FIG. 1 is a diagram schematically illustrating a configuration of a gas-liquid mixing device according to the present invention.

FIG. 2 is a flowchart simply illustrating a procedure for discharging a “gas reservoir” from the inside of a turbine pump in the gas-liquid mixing method according to the present invention.

[Explanation of symbols]

 Reference Signs List 8 liquid tank 9 liquid 10 gas-liquid mixing pump (vertical type multi-stage turbine pump) 11 rotation control device 12 gas supply device 13 gas discharge exclusive pump 14 utilization path 15 discharge liquid return path 16 gas supply path 17 (exclusive for gas discharge) Liquid injection path 18 Liquid introduction path 19 Gas 20 Gas pool 24 Discharge liquid

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Norihito Asahi 86 Wakakusa-cho, Komaki-shi, Aichi F-term (reference) 4G035 AA01 AB04 AC29 AC35 AE13

Claims (8)

[Claims] 1. A gas-liquid mixing method for introducing a gas supplied from a gas producing apparatus and a liquid supplied from a liquid tank into a gas-liquid mixing pump and pressurizing and mixing the gas and liquid. Following the gas supply stopping step of stopping the gas supply to the gas-liquid mixing pump and the discharge liquid discharging step of discharging the liquid discharged from the gas-liquid mixing pump, the gas-liquid mixing pump is switched to low-speed operation, A gas-liquid mixing method, comprising a step of discharging a gas pool staying in the gas-liquid mixing pump by a liquid introducing step of introducing the liquid from the tank to the gas-liquid mixing pump. 2. The gas-liquid mixing method according to claim 1, wherein in the liquid introducing step, the liquid is press-fitted from the liquid tank into the gas-liquid mixing pump via a gas-exhausting pump. 3. The gas-liquid mixing method according to claim 1, wherein the discharging liquid discharging step is a step of refluxing the discharging liquid to a liquid tank. 4. The gas-liquid mixing pump is a vertical multi-stage turbine pump.
The gas-liquid mixing method according to any one of the above. 5. A gas-liquid mixing apparatus for introducing a gas supplied from a gas production apparatus and a liquid supplied from a liquid tank into a gas-liquid mixing pump to mix the gas and liquid under pressure, wherein the gas is supplied from the gas production apparatus. Gas supply stopping means for stopping the supply of the gas to be supplied to the gas-liquid mixing pump, discharging liquid discharging means for discharging the liquid discharged from the gas-liquid mixing pump, and reducing the rotation of the gas-liquid mixing pump. And a liquid introduction unit for introducing the liquid from the liquid tank to the gas-liquid mixing pump. 6. The gas-liquid mixing device according to claim 5, wherein said liquid introduction means press-injects said liquid from said liquid tank to said gas-liquid mixing pump via a gas purging pump. 7. The gas-liquid mixing device according to claim 5, wherein the discharge liquid discharging means is a means for returning the discharge liquid to a liquid tank. 8. The gas-liquid mixing device according to claim 5, wherein the gas-liquid mixing pump is a vertical multi-stage turbine pump.