JP2009219957A - Gas-liquid mixing system and gas-liquid mixing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a gas-liquid mixing system capable of precisely mixing a gas and a liquid by stably and easily controlling a feeding amount of the gas independently of the temperature, pressure or the like. <P>SOLUTION: The gas-liquid mixing system has a micro-mixer 3 for mixing at least one kind of gas with a liquid, and is equipped with mass flow control adjustment valves 2a and 2b for supplying a gas to the micro-mixer 3 while controlling the mass flow in a gas supply path and a pump 7 for liquid supply in a liquid supply path for sending a liquid to the micro-mixer. Thus gas-liquid can be mixed precisely. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a gas-liquid mixing system and a gas-liquid mixing method for mixing a liquid and at least one kind of gas.

  In the manufacturing process of chemicals, cosmetics, etc., mixing gas and liquid has been conventionally performed. When this gas-liquid mixing is performed using a micro mixer such as a micromixer or a microreactor, the gas flow rate is generally controlled by a pressure reducing valve, a throttle valve, and a flow meter. FIG. 3 shows a schematic diagram of a configuration for performing conventional gas-liquid mixing. A gas supply path 102 for sending gas to the micromixer 101 is provided with a pressure reducing valve 103, a throttle valve 104, and a flow meter 105. . A pump 106, a bifurcated joint 10, and a pressure gauge 107 are provided in the liquid supply path 108 that sends the liquid mixed with the gas to the micromixer 101.

  With the above configuration, the flow rate of the gas is controlled by passing through the pressure reducing valve 103, the throttle valve 104, and the flow meter 105, and the gas is supplied to the micromixer 101 through the gas supply path 102.

  On the other hand, the liquid sent out from the pump 106 is supplied to the micromixer 101 through the pressure gauge 107 and the liquid supply path 108. At this time, the pressure gauge 107 detects the pressure in the liquid supply path branched via the two-branch joint 10 and equal to the liquid supply path 9. The supplied gas and liquid are mixed by the micro mixer 101 and output.

In addition, although the micromixer which mixes two types of liquid is known conventionally, this micromixer mixes two types of liquids, and does not mix gas and a liquid ( Patent Document 1).
JP 2002-346353 A (paragraphs (0002) and (0003))

  Conventionally, gas and liquid are generally mixed by the configuration shown in FIG. In this case, when controlling the flow rate of the gas, the volume flow rate is measured and controlled based on this. The volume of the gas is controlled by the pressure and temperature of the liquid (reaction liquid that causes a chemical reaction by mixing with the gas and the chemical reaction). (Including both liquids that do not wake up).

  Further, in a micromixer such as a micromixer or a microreactor, pressure loss occurs because a liquid is passed through a narrow channel having an extremely small inner diameter. However, the generated pressure loss differs between gas and liquid, and control is difficult. In addition, the flow rate and viscosity of the reaction liquid, which is a liquid that causes a chemical reaction when mixed with gas, and the heat generated by the gas-liquid reaction also affect the volume of the gas, and the pressure required to feed the gas fluctuates. It becomes difficult. Specifically, when the pressure loss generated in the passage through which gas and liquid are mixed increases, the liquid flows back to the gas supply path, or the pump for sending the liquid is a propeller pump or the like. The gas mixed with the liquid flows backward to the pump side. For this reason, the subject that the flow of gas cannot be controlled correctly occurred.

  The present invention has been made in order to solve the above-mentioned problems, and is capable of stably and easily controlling the amount of gas sent without being influenced by temperature, pressure, etc., and accurately mixing the gas and the liquid. An object of the present invention is to provide a gas-liquid mixing system that can be performed.

In order to solve the above-described problem, a gas-liquid mixing system according to claim 1 of the present invention includes:
In a gas-liquid mixing system having a micromixer for mixing a liquid and at least one gas,
A mass flow control control valve for controlling the mass flow rate of the gas and supplying it to the micromixer is provided in the gas supply path to the micromixer, and for supplying liquid to the liquid supply path for sending liquid to the micromixer. It is characterized by having a pump.

Moreover, the gas-liquid mixing method according to claim 2 of the present invention includes:
In a gas-liquid mixing method in which a liquid and a gas are mixed using a micromixer having a structure in which a plurality of flow paths merge to form one discharge path.
At least one of the plurality of channels is used as a gas supply channel and at least one channel is used as a liquid supply channel,
A constant flow of liquid is continuously sent to the liquid supply path,
A gas-liquid mixture is taken out from the discharge path by continuously sending a gas at a constant flow rate to the gas supply path via mass flow control.

  According to the gas-liquid mixing system according to the first aspect and the gas-liquid mixing method according to the second aspect, the mass flow of the gas is controlled by the mass flow control control valve, and the gas is always stably supplied to the micro mixer. The problem caused by the change in the volume of the gas depending on the pressure and temperature is eliminated, and mixing with the liquid is performed with high accuracy.

  In addition, even if a liquid supply path is provided in the liquid supply path for sending the liquid to the micro mixer, the liquid can be prevented from flowing into the gas mass flow control valve side, and the liquid can be reliably supplied to the micro mixer. Feeding and mixing with gas can be performed with high accuracy.

  According to the gas-liquid mixing system and the gas-liquid mixing method according to the present invention, the mass flow rate control is performed without depending on the temperature, pressure, etc., and a constant flow rate is stably sent to the micro mixer. Mixing with the liquid is performed with high accuracy.

  In addition, the mass of the gas is automatically controlled by the mass flow control control valve and sent to the micromixer, and the liquid is reliably sent to the micromixer by the pump. Is called.

  Hereinafter, a gas-liquid mixing system according to an embodiment of the present invention will be described with reference to the drawings. In addition, the specific dimensions of the pipes shown below are only examples, and are not limited to this dimensional relation as long as the pipes have a small diameter applicable to the micromixer used in the present invention. .

  FIG. 1 is a block diagram showing a configuration of a gas-liquid mixing system according to an embodiment of the present invention. The branch valve 1 selects either the mass flow control valve 2a or the mass flow control valve 2b. A check valve 5 and a joint portion 6 are provided between the branch valve 1 and the micromixer 3.

  The gas supply passages 4 extending from the outlet side of the mass flow control valves 2a and 2b having 1/8 (outside diameter 3.2 mm) joint portions 2a-1 and 2b-1 on the inlet side to the branch valve 1 are respectively provided. For example, a 1/4 (outside diameter 6.4 mm) pipe, a gas supply path 4 from the branch valve 1 to the check valve 5 is, for example, a 1/4 (outside diameter 6.4 mm) SUS pipe, and the check valve 5 to the joint portion 6. For example, the gas supply path 4 leading to the SUS pipe is 1/8 (outer diameter 3.2 mm), and the gas supply path 4 from the joint 6 to the micromixer 3 is 1/8 (outer diameter 3.2 mm), for example. It has a size and is connected with a resin tube having excellent corrosion resistance such as fluororesin (Teflon (registered trademark)) and excellent visibility in the tube from the outside. Resin joints 4-1 and 4-2 having excellent corrosion resistance such as fluororesin (Teflon (registered trademark)) for connecting to the joint portion 6 and the micro mixer 3 are provided at the ends of the resin tube. Is provided.

  The branch valve 1 selects either the gas A output from the mass flow control valve 2a with the mass flow controlled or the gas B from the mass flow control valve 2b with the mass flow controlled to select the check valve 5 To supply. As the mass flow control valve 2a and the mass flow control valve 2b, for example, a flow control device disclosed in Japanese Patent Laid-Open No. 2000-020137 is used. The flow rate control device includes, for example, a flow path 21 through which gas flows, a control valve 22 that controls the flow rate of gas flowing through the flow path 21, a flow rate detection sensor 23 that detects the flow rate of gas flowing through the flow path 21, and this flow rate. The control unit 24 is configured to control the control valve 22 so that the output flow rate becomes constant based on the flow rate detection value detected by the detection sensor 23.

  As the flow rate detection sensor 23, a thermal minute mass flow rate sensor using semiconductor technology is used. As this minute mass flow sensor, for example, a flow sensor disclosed in JP-A No. 2002-122454 is preferably used. This flow sensor has a heat generating part formed on the diaphragm of the silicon chip and two temperature detecting parts formed on the diaphragm on the upstream side and the downstream side of the heat generating part. The flow rate corresponding to the flow rate is obtained from the power supplied to the heat generating unit necessary to keep the temperature difference detected by the unit constant, or the heat generating unit is heated with a constant current or constant power, and the two temperature detecting units The flow rate can be obtained from the detected temperature difference.

  The pump 7 pressurizes the liquid and sends it out to the liquid supply path 9. At this time, the pressure gauge 8 detects the pressure of the liquid which is the pressure in the liquid supply path branched via the two-branch joint 10 and is equal to the liquid supply path 9, and this detected value is detected by the control unit (see FIG. (Not shown) to protect when the pressure of the liquid delivered from the pump 7 rises above a set value. The liquid sent out from the pump 7 is supplied to the micromixer 3 through a liquid supply path 9 made of, for example, a 1/8 (outer diameter 3, 2 mm) SUS pipe. The pump 8 may be any one of a variable displacement pump such as a piston and a vane pump, a constant displacement pump such as a gear and a screw pump, a turbo pump, and the like, and is used for feeding a liquid having a constant flow rate.

  The “constant flow rate” here is determined by the performance of the pump used. For example, in a pump in which the rotation speed of an electric motor that drives the pump is guaranteed as a product specification, the discharge flow rate itself is not guaranteed. Even if the fluctuation range of the rotational speed is ± 5%, the fluctuation range of the discharge amount may be ± 10%. In such a pump, a flow rate including ± 10% that is the fluctuation range of the actual discharge amount is regarded as a “constant flow rate”. What kind of flow capacity is used depends on the application needs.

  Next, the operation (action) of the gas-liquid mixing system described above will be described. The gas A is controlled by the mass flow control valve 2a without being affected by temperature, pressure, etc., and is supplied to the branch valve 1 at a constant mass flow rate. On the other hand, the gas B is also controlled by the mass flow control valve 2b without being affected by temperature, pressure, etc., and supplied to the branch valve 1 at a constant mass flow.

  Here, if the branch valve 1 uses the gas A, the mass flow control control valve 2 a is selected and the gas A is sent to the check valve 5. If the gas B is used, the mass flow control valve 2 b is selected and the gas B is sent to the check valve 5. And the gas A or gas B sent out from the check valve 5 is supplied to the micro mixer 3 through the gas supply path 4 which consists of resin tubes.

  On the other hand, the liquid sent out by the pump 7 is supplied to the micromixer 3 through the liquid supply path 9. In the micromixer 3, the supplied gas A or gas B and the liquid are mixed and output.

  As described above, according to the present invention, the mass flow control of the gas A or the gas B depends on the temperature, the pressure, etc. by providing the mass flow control control valve 2a or the mass flow control control valve 2b in the gas supply path. Since the flow is supplied to the micromixer 3 as a constant flow rate, the amount of gas to be sent can be controlled stably and easily, and mixing with the liquid is performed with high accuracy.

  In the above embodiment, the case where the gas A or the gas B is selected and mixed with the liquid has been described. However, one type of gas and one type of liquid are always mixed without selection. Two or more kinds of gases and one kind of liquid can be mixed.

  FIG. 2 is a block diagram showing a configuration diagram of a gas-liquid mixing system that mixes two types of gas and one type of liquid. The gas A is supplied to the micromixer 3 through a gas supply path 4a having a mass flow control valve 2a, a check valve 5a, and a joint 6a. The gas supply path 4a from the mass flow control valve 2a having the joint portion 2a-1 on the inlet side to the check valve 5a is, for example, 1/4 (outer diameter 6.4 mm) piping, from the check valve 5a to the joint portion 6a. The gas supply path 4a is connected by, for example, a 1/8 (outer diameter 3, 2 mm) SUS pipe, and the gas supply path 4a from the joint 6a to the micromixer 3 is, for example, 1/8 (outer diameter 3, 2 mm). Connected with resin tube.

  The gas B is supplied to the micromixer 3 through the mass flow control valve 2b, the check valve 5b, and the resin joint 6b. The gas supply path 4b from the mass flow control valve 2b having the joint portion 2b-1 on the inlet side to the check valve 5b is, for example, a 1/4 (outer diameter 6.4 mm) pipe, and from the check valve 5b to the joint portion 6b. The gas supply path 4b is connected with, for example, a 1/8 (outer diameter 3, 2 mm) SUS pipe, and the gas supply path 4b from the joint 6b to the micromixer 3 is, for example, 1/8 (outer diameter 3, 2 mm). Connected with resin tube.

  The liquid is supplied to the micromixer 3 through the liquid supply path 9 by the pump 7. The liquid supply path 9 extending from the pump 7 to the micromixer 3 is connected by, for example, 1/8 (outer diameter 3, 2 mm) pipe.

  The mass flow control control valves 2a and 2b, check valves 5a and 5b, resin joints 6a and 6b, the micro mixer 3, the pump 7, the pressure gauge 8, the bifurcated joint 10 and the like are shown in FIG. Since the control and control valves 2a and 2b, the check valve 5, the resin joint 6, the micro mixer 3, the pump 7 and the pressure gauge 8 are the same, a duplicate description is omitted.

  Next, the operation (action) of the gas-liquid mixing system described above will be described. The gas A is controlled by the mass flow control valve 2a without being affected by temperature, pressure, etc., and is supplied to the check valve 5a as a constant flow rate. For example, SUS of 1/8 (outer diameter 3, 2 mm) is supplied. The micro-mixer 3 is supplied through, for example, a 1/8 (outer diameter 3, 2 mm) resin tube connected to the pipe and the joint 6a.

  The gas B is controlled by the mass flow control valve 2b without being affected by temperature, pressure, etc., and is supplied to the check valve 5b as a constant flow rate, for example, 1/8 (outer diameter 3, 2 mm). ), And a 1/8 (outer diameter 3, 2 mm) resin tube connected to the joint portion 6b.

  On the other hand, the liquid sent to the pressure gauge 8 by the pump 7 is supplied from the pressure gauge 8 to the micromixer 3 through the liquid supply path 9 of the copper tube. In this manner, the gas A, gas B, and liquid supplied to the micromixer 3 are mixed and output in the micromixer 3.

  According to the above-described gas-liquid mixing system, the gas A is controlled by the mass flow rate control valve 2a, and the gas B is controlled by the mass flow rate control control 2b. Is supplied to the micromixer 3, the amount of the two kinds of gas A and gas B to be fed can be controlled stably and easily, so that the mixing with the liquid is performed with high accuracy.

  In the illustrated embodiment, a joint portion 6 is provided at the other end of the SUS tube having a check valve 5 connected to one end, and the joint portion 6 and the micromixer 3 are connected by a transparent resin tube. However, this makes it possible to quickly confirm visually that the liquid has flowed back into the gas supply path by utilizing the transparency of the resin tube. Therefore, it is not always necessary to connect a transparent resin tube. A copper tube may be used instead of the SUS tube.

  As described above, according to the gas-liquid mixing system and the gas-liquid mixing method according to the present invention, when mixing a liquid and at least one kind of gas using a micromixer as in the prior art, especially mixing with gas The flow rate and viscosity of the reaction liquid, which is a liquid that causes a chemical reaction, affects the volume of the gas due to the heat generated by the gas-liquid reaction, and the pressure required to send the gas fluctuates, making it difficult to control We were able to solve. Specifically, when the pressure loss generated in the passage through which the gas and liquid are mixed increases, the liquid flows back into the gas supply path, or when the pump that pumps the liquid is a propeller pump, the liquid is mixed with the liquid. It was possible to solve the problem that the flow of gas could not be accurately managed and controlled due to the reverse flow of gas to the pump side.

It is a block diagram which shows the structure of the gas-liquid mixing system concerning one Embodiment of this invention. It is a block diagram which shows the block diagram of the gas-liquid mixing system which mixes two types of gas and one type of liquid. It is a schematic diagram of the structure which performs the conventional gas-liquid mixing.

Explanation of symbols

1 Branch valve 2a, 2b Mass flow control valve 2a-1, 2b-1 Joint part 3 Micro mixer 4, 4a, 4b Gas supply path 4-1, 4-2 Resin joint 5, 5a, 5b Check valve 6 , 6a, 6b Joint part 7 Pump 8 Pressure gauge 9 Liquid supply path 10 Bifurcated joint 21 Flow path 22 Control valve 23 Flow rate detection sensor 24 Control part 101 Micro mixer 102 Gas supply path 103 Pressure reducing valve 104 Throttle valve 105 Flow meter 106 Pump 107 Pressure gauge 108 Liquid supply path A, B Gas

Claims (2)

In a gas-liquid mixing system having a micromixer for mixing a liquid and at least one gas,
A mass flow control control valve for controlling the mass flow rate of the gas and supplying it to the micromixer is provided in the gas supply path to the micromixer, and for supplying liquid to the liquid supply path for sending liquid to the micromixer. A gas-liquid mixing system comprising a pump. In a gas-liquid mixing method in which a liquid and a gas are mixed using a micromixer having a structure in which a plurality of flow paths merge to form one discharge path.
At least one of the plurality of channels is used as a gas supply channel and at least one channel is used as a liquid supply channel,
A constant flow of liquid is continuously sent to the liquid supply path,
A gas-liquid mixing method, wherein a gas-liquid mixture is taken out from the discharge path by continuously sending a gas at a constant flow rate to the gas supply path via mass flow control.

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