JP5558854B2 - Liquid mixing method and liquid mixing apparatus - Google Patents

Description

  The present invention relates to a liquid mixing method and a liquid mixing apparatus, and in particular, for supplying A liquid pipe for supplying A liquid stored in the A liquid tank and for supplying B liquid stored in the B liquid tank. The present invention relates to a liquid mixing method for obtaining a mixed liquid obtained by mixing a liquid B and a liquid B at a desired ratio by introducing the liquid B to a mixed liquid pipe when the B liquid pipe is joined.

14 to 19 are schematic configuration diagrams for explaining a conventional liquid mixing apparatus.
In the liquid mixing apparatus shown in FIG. 14, the A liquid pipe 103 a from the A liquid tank 101 a and the B liquid pipe 103 b from the B liquid tank 101 b are connected by the tees 105, and provided in the mixed liquid pipe 107 from the tees 105. This is a system in which the liquid A and the liquid B are mixed by the mixer 109 and the mixed liquid is fed to the use point. In this system, the flow velocity in the pipes 103a, 103b, 107 is ensured by gravity drop.

  The mixing ratio of the liquid A and the liquid B is the cross-sectional area of the pipes 103a and 103b between the liquid A flow rate variable valve 111a provided in the liquid A pipe 103a and the liquid B flow rate variable valve 111b provided in the liquid B pipe 103b. It adjusts by adjusting and making the flow volume of A liquid and B liquid variable. In order to adjust the flow rates of the liquid A and the liquid B, the indicated values of the liquid A flow meter 113a and the liquid B flow meter 113b provided downstream of the variable flow valves 111a and 111b are used.

  The liquid mixing apparatus shown in FIG. 15 is a system in which a liquid feed pump 115 is provided in the liquid mixture pipe 107 in addition to the configuration shown in FIG. In this system, the flow rate in the pipes 103a, 103b, 107 is secured by the liquid feed pump 115. The liquid feed pump 115 is inserted on the downstream side of the mixer 109.

  In this case, the mixing ratio of the liquid A and the liquid B is adjusted by adjusting the cross-sectional areas of the pipes 103a and 103b with the variable flow rate valves 111a and 111b so that the flow rates of the liquid A and the liquid B are variable. . In order to adjust the flow rates of the liquid A and the liquid B, the indicated values of the liquid A flow meter 113a and the liquid B flow meter 113b provided downstream of the variable flow valves 111a and 111b are used.

  The liquid mixing apparatus shown in FIG. 16 includes an A liquid feed pump 117a in the A liquid pipe 103a and a B liquid feed pump in the B liquid pipe 103b, instead of the flow rate variable valves 111a and 111b having the configuration shown in FIG. The system provided with 117b. In this system, the flow rates in the pipes 103a, 103b, and 107 are secured by the liquid feed pumps 117a and 117b.

  In this liquid mixing apparatus, the mixing ratio of liquid A and liquid B can be changed by changing the operating rates of the liquid feed pumps 117a and 117b and making the flow rates in the pipes 103a and 103b of liquid A and liquid B variable. Adjusted. In order to adjust the flow rates of the liquid A and the liquid B, the indicated values of the liquid A flow meter 113a and the liquid B flow meter 113b provided downstream of the liquid feed pumps 117a and 117b are used.

The liquid mixing apparatus shown in FIG. 17 is a system that includes a buffer tank 119 in place of the tees 105 having the configuration shown in FIG. 16 and a mixer 121 in the buffer tank in place of the mixer 109.
The liquid A and the B liquid are put into the buffer tank 119 from the A liquid tank 101a and the B liquid tank 101b by the liquid feed pumps 117a and 117b. The indication values of the liquid A flow meter 113a and the liquid B flow meter 113b are used to adjust the flow rates of the liquid A and the liquid B.

In this system, the liquid A flow meter 113a and the liquid B flow meter 113b are, for example, integrated flow meters. Since the integrated values of the flow meters 113a and 113b are stored in the buffer tank 119 while the A liquid and the B liquid remain in the buffer tank 119, the mixing ratio of the A liquid and the B liquid can be obtained by calculation. it can.
The liquid A and the liquid B are mixed by the mixer 121 installed in the buffer tank 119. After the mixing is completed, the liquid mixture is sent to the use point.

FIG. 18 shows a system provided with a level gauge 123 in place of the flow meters 113a and 113b having the configuration shown in FIG.
The liquid A and the B liquid are put into the buffer tank 119 from the A liquid tank 101a and the B liquid tank 101b by the liquid feed pumps 117a and 117b. A liquid level gauge 123 is installed in the buffer tank 119. First, the buffer tank 119 is emptied, the liquid feed pump 117a is operated, and the liquid A is supplied to the buffer tank 119 until the specified liquid level is reached. Put in. Next, the liquid feed pump 117b is operated and put into the B liquid buffer tank 119 until the specified liquid level is reached. Based on the liquid level in the buffer tank 119, the volumes of the liquid A and the liquid B entering the buffer tank 119 are obtained. From the capacity value, the mixing ratio of liquid A and liquid B is obtained by calculation. Thereafter, the liquid A and the liquid B are mixed by the mixer 121 installed in the buffer tank 119. After the mixing is completed, the liquid mixture is sent to the use point.

  In the liquid mixing apparatus shown in FIG. 19, the A liquid pipe 103 a from the A liquid tank 125 a and the B liquid pipe 103 b from the B liquid tank 125 b are connected by the tees 105, and provided in the mixed liquid pipe 107 from the tees 105. This is a system in which the liquid A and the liquid B are mixed by the mixer 109 and the mixed liquid is fed to the use point. The A liquid tank 125a and the B liquid tank 125b are containers capable of pressurizing the inside. Connected to the A liquid tank 125a is a pressurizing pipe 127a for pressurizing the space above the A liquid. A pressurizing pipe 127b for pressurizing the space above the B liquid is connected to the B liquid tank 125b. The pressurizing pipes 127a and 127b are both connected to the pressurizing pipe 127. In this system, a constant pressure is applied to the A liquid tank 125a and the B liquid tank 125b to secure the flow velocity in the pipes 103a, 103b, and 107.

  The mixing ratio of the liquid A and the liquid B is the cross-sectional area of the pipes 103a and 103b between the liquid A flow rate variable valve 111a provided in the liquid A pipe 103a and the liquid B flow rate variable valve 111b provided in the liquid B pipe 103b. It adjusts by adjusting and making the flow volume of A liquid and B liquid variable. In order to adjust the flow rates of the liquid A and the liquid B, the indicated values of the liquid A flow meter 113a and the liquid B flow meter 113b provided downstream of the variable flow valves 111a and 111b are used.

The conventional liquid mixing apparatus described with reference to FIGS. 14 to 19 can be broadly classified into two groups, that is, the group shown in FIGS. 14 to 16 and 19 and the group shown in FIGS.
The former measures the liquid flow rate of liquid A and liquid B at any time using flow meters 113a and 113b without a buffer tank, calculates the mixing ratio from the measured data, and controls the mixed liquid that is controlled to the specified mixed value. Can be sent to a use point.
The latter FIG. 17 uses the flow meters 113a and 113b, and FIG. 18 uses the liquid level meter 123 to calculate the liquid volume in the buffer tank 119 and calculate the mixing ratio.

  The latter group has the following problems. (1) Compared with the former group, it is mixed by batch processing and lacks rapidity. (2) The liquid for the buffer tank always exists, and a residual liquid is generated, which may reduce the liquid use efficiency. (3) If the buffer tank becomes bulky and the apparatus itself becomes large, the cost increases accordingly. (4) Uneven mixing is likely to occur.

  18 measures the liquid volume in the buffer tank 119 by the liquid level gauge 123. From the weight measurement of the buffer tank 119, the amounts of the A liquid and the B liquid in the buffer tank 119 are determined. Sometimes measured. In this case, a weight sensor is used as the weight measuring means, but there is a problem that the price is generally high.

The liquid mixing devices of FIGS. 14 to 16 and 19 which are the former group can be classified into those using the flow rate variable valves 111a and 111b (FIGS. 14, 15 and 19) and those not (FIG. 16). .
The flow rate variable valves 111a and 111b in the liquid mixing apparatus shown in FIGS. 14, 15, and 19 adjust the flow rate by adjusting the opening of the valve, and are generally used. Depending on the pressure and operating speed, the appropriate one is selected. Depending on the type of variable flow rate valve, there is a problem that reliability is lowered due to its high price or complexity. Further, when chemical resistance is required, a fluororesin must be used for the wetted part, and there is a problem that the reproducibility is inferior due to the creep characteristics of the fluororesin.

  The liquid mixing apparatus of FIG. 16 changes the flow rate by adjusting the operating rate of the liquid feed pumps 117a and 117b instead of the flow rate variable valve. In the case of a liquid feed pump, it is the same as a variable flow valve, and a pump suitable for the type, temperature, pressure, and operating speed of the liquid is selected. Similar to the variable flow rate valve, depending on the type of the liquid delivery pump, there is a problem that it is expensive or complicated and the reliability is lowered.

  Patent Document 1 discloses a liquid mixing apparatus that does not use a buffer tank, a liquid A flow rate variable valve, a liquid B flow rate variable valve, a liquid A feed pump, and a liquid B feed pump. FIG. 20 shows a schematic configuration diagram of the liquid mixing apparatus.

  In the liquid mixing apparatus shown in FIG. 20, the A liquid pipe 103a from the A liquid tank 125a and the B liquid pipe 103b from the B liquid tank 101b are coupled by an aspirator 129, and the A liquid and the B liquid pipe 107 from the aspirator 129 are combined. This is a system in which the liquid B is mixed and the liquid mixture is sent to a use point. The A liquid tank 125a is a container capable of pressurizing the inside. Connected to the A liquid tank 125a is a pressurizing pipe 127a for pressurizing the space above the A liquid.

When a certain pressure is applied to the A liquid tank 125 a and the A liquid is caused to flow into the aspirator 129, the B liquid flows into the aspirator 129 by the suction force generated in the aspirator 129, and the A liquid and the B liquid are mixed in the mixed liquid pipe 107. Mixed.
In this system, the flow velocity in the pipes 103a, 103b, 107 is ensured by pressurization in the liquid A tank 125a.

  20 includes a teat 131 and a mixed solution stop valve 133 in order from the aspirator 129 side in the mixed solution pipe 107. A drain pipe 135 is connected to the tees 131. A drain stop valve 137 is provided in the drain pipe 135.

  Immediately after the liquid A starts to flow into the aspirator 129, the mixing ratio of the liquid A and the liquid B in the liquid mixture pipe 107 is not accurate, so the liquid mixture stop valve 133 is closed and the drain stop valve 137 is opened. The mixed liquid is guided from the teeth 131 to the drain pipe 135. After a predetermined time, the mixed solution stop valve 133 is opened, the drain stop valve 137 is closed, and the mixed solution is guided to the use point.

  FIG. 14 to FIG. 20 schematically show a conventional mixing system, and the flowmeter, variable flow valve, teas, mixer, liquid feed pump, and buffer tank can function even if the shape and mechanism change. Are the same, the actual liquid mixing device can be divided into categories.

JP 2000-42390 A JP-A-10-320056

  The liquid mixing apparatus shown in FIG. 20 does not include the buffer tank, the liquid A flow rate variable valve, the liquid B flow rate variable valve, the liquid A feed pump, and the liquid B feed pump.

  However, in the liquid mixing apparatus shown in FIG. 20, in order to generate a suction force in the aspirator 129, a high pressure must be applied to the A liquid tank 125a, and the A liquid tank 125a that can withstand high pressure is necessary. was there. In the case of using a high-pressure tank, it is necessary to provide a facility for preventing the tank from bursting in preparation for when a predetermined pressure or more is applied in the tank due to a failure or the like. The equipment is, for example, a safety valve or a design that does not rupture even when pressure over the design is applied, but the cost is high, the equipment becomes complicated, and the number of parts increases. Reliability decreases.

  Further, the liquid mixing apparatus shown in FIG. 20 has a problem of the aspirator itself. For example, there is a problem that the aspirator must be changed in order to change the mixing ratio of liquid A and liquid B. In addition, mixing using an aspirator has a problem that the mixing ratio is difficult to stabilize, the aspirator is expensive, and the mixing ratio in mixing using an aspirator is not linear with respect to the flow rate.

  The present invention joins the A liquid pipe for feeding the A liquid stored in the A liquid tank and the B liquid pipe for feeding the B liquid stored in the B liquid tank to mix the mixed liquid pipe. In a liquid mixing method for obtaining a mixed liquid obtained by mixing A liquid and B liquid at a desired ratio in a mixed liquid pipe and a liquid mixing apparatus used therefor, the object is to reduce the manufacturing cost of the apparatus.

In the liquid mixing method according to the present invention, the A liquid pipe for feeding the A liquid housed in the A liquid tank and the B liquid pipe for feeding the B liquid housed in the B liquid tank are merged. A liquid mixture method for obtaining a mixed liquid obtained by mixing A liquid and B liquid at a desired ratio in the mixed liquid pipe, using a liquid feed pump as liquid feeding means, By using a container whose pressure can be adjusted as the B liquid tank, and changing the pressure in the A liquid tank and the pressure in the B liquid tank relatively, the ability to send A liquid and the B liquid are sent. The A liquid flow rate and the B liquid flow rate are changed by controlling the ability to perform, and the mixing ratio of the A liquid and the B liquid in the mixed liquid is changed.

The liquid mixing apparatus according to the present invention includes an A liquid pipe for feeding A liquid contained in the A liquid tank, a B liquid pipe for feeding B liquid contained in the B liquid tank, and A A liquid mixing apparatus including a liquid pipe and a liquid mixture pipe in which the liquid B pipe is merged, liquid is fed by a liquid feed pump , and the liquid A tank and the liquid B tank are containers whose pressure can be adjusted, A liquid tank internal pressure adjustment mechanism for adjusting the pressure in the liquid A tank, and a liquid B tank pressure mechanism for adjusting the pressure in the liquid B tank, and the liquid A tank pressure adjustment liquid feed pressure of the liquid a in the tank by a mechanism, by relatively changing the pressure of the liquid B tank by the liquid B tank pressure regulating mechanism, the ability and liquid B for feeding the liquid a The mixing ratio of liquid A and liquid B in the liquid mixture To change the.

  When the pressure applied to the A liquid surface in the A liquid tank and the pressure applied to the B liquid surface in the B liquid tank are changed relatively, the A liquid flow rate in the A liquid pipe and the B liquid in the B liquid pipe Since the ratio of the flow rate changes and the mixing ratio of liquid A and liquid B in the liquid mixture changes, the liquid A and liquid B are desired by controlling the pressure on the liquid A level and the pressure on the liquid B level. A mixed solution mixed at a ratio of

  Further, by setting the pressure difference between the A liquid tank and the B liquid tank to a certain level or higher, only the A liquid or the B liquid can be obtained without providing a switching valve such as a stop valve in the A liquid pipe and the B liquid pipe. It is also possible to flow only through the mixed solution piping. However, in the liquid mixing apparatus of the present invention, it is not excluded to dispose a switching valve such as a stop valve in the A liquid pipe and the B liquid pipe.

The reason why only the liquid A or the liquid B can flow without using the stop valve is as follows. The flow path of liquid A and liquid B is created at the confluence of liquid A and pipe B, but the difference between the liquid supply pressure of liquid A and the liquid supply pressure of liquid B exceeds a certain value. When pressure is applied and only the A liquid flows out to the confluence portion of the A liquid pipe and the B liquid pipe, a flow path of only the A liquid is formed in the confluence portion. The flow path is like a pipe made of the A liquid itself because of the viscosity of the liquid, and the situation is such that the entrance of the B liquid into the merged portion is prevented. In this state, even if some pressure is applied to the B liquid side, the B liquid does not flow into the merged part unless the flow path barrier of the A liquid can be broken.
In a situation where both the liquid A and the liquid B flow into the merged portion (proportional region in the embodiment described later), the flow rates are mixed in proportion to the pressure ratio applied to each liquid.

In the liquid mixing method and a liquid mixing apparatus of the present invention, the pressure of the pressure and the liquid B in the tank of the liquid A in the tank is a negative pressure relative to atmospheric pressure of place where a the tank.

  An example of the pressure resistance of the liquid A tank and the liquid B tank is a low pressure resistance within a range of about −0.1 MPa (megapascal) to about 10,000 Pa (pascal).

In the liquid mixing method and the liquid mixing apparatus of the present invention, if various conditions are constant, the ratio of the liquid A to the liquid B in the liquid mixture can be controlled by controlling the pressure to the liquid A level and the pressure to the liquid B level. The flow rate of the liquid mixture can be determined.
As fluctuations in various conditions, for example, it is known that when the liquid level of the liquid A tank and the liquid level of the liquid B tank change, the flow rates of liquid A and liquid B change (see Patent Document 2). ). In addition, as the inventors' knowledge, the mixing ratio of the liquid A and the liquid B varies depending on the temperatures of the liquid A and the liquid B, the temperature of the pipe, the liquid A flow rate, and the liquid B flow rate. Therefore, there are cases where a liquid mixture having a desired mixing ratio cannot be obtained only by the pressure value applied to the liquid surfaces of the liquid A and the liquid B.

  In such a case, a sensor correlating to the flow rate such as a flow meter is provided in the A liquid pipe and the B liquid pipe so that the A liquid and the B liquid have a predetermined flow rate in the A liquid tank and the B liquid tank. The pressure applied to the liquid level may be controlled and adjusted.

  In addition, a sensor for measuring a value correlated with the ratio of the A liquid and the B liquid after mixing the A liquid and the B liquid is provided in the mixed liquid piping so that a desired mixing ratio is obtained. The pressure applied to the liquid level in the liquid tank may be controlled and adjusted.

  In the liquid mixing apparatus of the present invention, a mixer may be installed in the liquid mixture pipe in order to reliably mix the liquid A and the liquid B. When the sensor is provided in the mixer and the liquid mixture pipe, the sensor is preferably provided on the downstream side of the mixer. However, the position where the mixer is arranged in the mixed liquid pipe is not particularly limited, and is an arbitrary position of the mixed liquid pipe.

  When the point of use, which is the outlet after mixing, is provided at a location lower than the liquid level of the A liquid tank and the B liquid tank, gravity drop as liquid A, B liquid and liquid mixture feeding means Can be used. In this case, the pressure applied to the A liquid tank and the B liquid tank also becomes the pressure for sending the liquid to the use point as it is.

When the pipes are thin from the A liquid tank and the B liquid tank to the use point, or when the viscosity of each liquid is high, the pressure required for liquid supply is often high.
In that case, in the prior art, the liquid A tank and the liquid B tank need to be high pressure tanks.

In the liquid mixing apparatus of the present invention, in order to cope with such a case, and a liquid feed pump to the mixed liquid pipe. By sending the liquid in the mixed liquid pipe by the liquid feed pump, it is not necessary to use high pressure-resistant A liquid tank and B liquid tank. The position at which the liquid feed pump is arranged in the mixed liquid pipe is not particularly limited, and is an arbitrary position in the mixed liquid pipe.

  When adjusting the high pressure applied to each tank, the control error is substantially proportional to the pressure. For example, when pressure is applied at 1 MPa, a pressure control device with 1% accuracy can be controlled with a pressure accuracy of 0.01 MPa. When pressure is applied at 0.1 MPa with a pressure control device having the same accuracy, the pressure can be controlled with a pressure accuracy of 0.001 MPa. That is, when the pressure applied to the liquid A tank and the liquid B tank is adjusted, pressure control with higher accuracy can be performed at a low pressure than when a high pressure is applied.

In addition, the liquid in the tank may be a chemical liquid that is harmful to the human body. In Patent Document 1, hydrofluoric acid is used. In Patent Document 1, although it is not described in Patent Document 1 that atmospheric pressure is not applied to the hydrofluoric acid side tank, it is intended to prevent scattering of hydrofluoric acid due to rupture of the tank at the time of equipment trouble Conceivable.
In addition, the high pressure tank has a structure that is thick and sturdy and large in size, and there is a problem that the cost of the tank itself increases due to the provision of a safety valve.

In the present invention, a liquid feed pump is installed in the mixed liquid pipe, and suction is performed from each tank side, so that the pressure from the discharge side of the liquid feed pump to the use point can be over atmospheric pressure. In this case, the pressure in the pipe from the liquid A tank and the liquid B tank to the inlet side of the pump can be equal to or lower than the atmospheric pressure. And even if the pipe leaks due to trouble or the pipe joint is disconnected, the liquid does not scatter and the safety is improved.
Furthermore, the pressure adjustment of the A liquid tank and the B liquid tank may be performed with a slight differential pressure, and highly accurate pressure control is possible.
Furthermore, since the pressure in the A liquid tank and the B liquid tank is negative (pressure lower than atmospheric pressure) , a pressure mechanism is not required as the pressure adjusting mechanism in the A liquid tank and the pressure adjusting mechanism in the B liquid tank. The opening of the valve provided in the flow path between the outside of the A liquid tank (atmospheric pressure) and the inside of the A liquid tank, and the flow path between the outside of the B liquid tank (atmospheric pressure) and the inside of the B liquid tank Each tank internal pressure can be adjusted only by controlling the opening of the valve.

  Incidentally, the conventional liquid mixing apparatus shown in FIG. 20 includes a drain pipe 135 and stop valves 133 and 137 in order to branch the mixed liquid pipe 107. The stop valve is similar in structure to the variable flow valve and has the same problems as the variable flow valve described above.

Therefore, in the liquid mixing method of the present invention, the first branch pipe and the second branch pipe are connected to the outlet of the mixed liquid pipe, and the branch pipe tank made of a container capable of adjusting the pressure is connected to the outlet of the first branch pipe. The flow rate ratio of the liquid flowing to the first branch pipe side and the liquid flowing to the second branch pipe side may be changed by changing the pressure in the first branch pipe tank.
In the liquid mixing apparatus of the present invention, a first branch pipe and a second branch pipe branched from the mixed liquid pipe, and a branch pipe tank comprising a pressure-adjustable container connected to an outlet of the first branch pipe. A branch pipe tank pressure adjusting mechanism for adjusting the pressure in the branch pipe tank may be further provided.
Here, the outlet of the second branch pipe is, for example, a use point, and may be atmospheric pressure or a pressure larger than atmospheric pressure.

By changing the pressure in the branch pipe tank, the difference between the pressure in the first branch pipe and the pressure in the second branch pipe can be adjusted. When this pressure difference is set above a certain level, the liquid can flow only to the first branch pipe side or to the second branch pipe side, and the liquid can be branched without a switching valve such as a stop valve. it can. Thereby, the manufacturing cost of the liquid mixing apparatus can be further reduced.
In order to obtain a branching ratio with high accuracy, the liquid flow rate of the first branch pipe and / or the second branch pipe is measured with a sensor, and the second branch pipe and the second branch pipe are compared with each other based on the deviation from the desired value. What is necessary is just to control the differential pressure | voltage in branch piping, and to obtain a desired flow volume in each branch piping.

An example of the pressure resistance of the branch piping tank is a low pressure resistance within a range of about −0.1 MPa to about 10,000 Pa.
Moreover, when using a liquid feed pump, a liquid feed pump is arrange | positioned at liquid mixture piping or 2nd branch piping.

In the liquid mixing method of the present invention, a container capable of adjusting the pressure is used as the A liquid tank and the B liquid tank, and the pressure applied to the A liquid surface in the A liquid tank and the pressure applied to the B liquid surface in the B liquid tank are relative to each other. The mixing ratio of the liquid A and the liquid B in the liquid mixture was changed.
In the liquid mixing apparatus of the present invention, the A liquid tank and the B liquid tank are containers capable of adjusting the pressure, and the A liquid tank pressure adjusting mechanism for adjusting the pressure in the A liquid tank, and the pressure in the B liquid tank are adjusted. A liquid B tank internal pressure mechanism for adjusting, a pressure applied to the A liquid surface in the A liquid tank by the A liquid tank pressure adjusting mechanism, and a B liquid in the B liquid tank by the B liquid tank pressure adjusting mechanism. By changing the pressure applied to the surface relatively, the mixing ratio of the liquid A and the liquid B in the liquid mixture was changed.
As a result, mixing of liquid A and liquid B in a desired mixing ratio without using a buffer tank, liquid A flow rate variable valve, liquid B flow variable valve, liquid A feed pump, liquid B feed pump and aspirator A liquid can be obtained and the manufacturing cost of the liquid mixing apparatus can be reduced.

In the liquid mixing method and a liquid mixing apparatus of the present invention, the pressure of the pressure and the liquid B in the tank of the liquid A in the tank, or to be a negative pressure relative to atmospheric pressure of place where a those tanks, If the pressure resistance of the liquid A tank and the liquid B tank is a low pressure within the range of about -0.1 MPa to about 10,000 Pa, an expensive high pressure tank is not used, thereby reducing the manufacturing cost of the liquid mixing device. it can. Furthermore, since the pressure is applied to the liquid level A and the liquid level B within a range of low pressure, the accuracy of pressure control is increased as compared with the case where a high pressure is used, and consequently the accuracy of the mixing ratio is improved.

In the liquid mixing method of the present invention, the first branch pipe and the second branch pipe are connected to the outlet of the mixed liquid pipe, and the branch pipe tank made of a container capable of adjusting the pressure is connected to the outlet of the first branch pipe. You may make it change the flow rate ratio of the liquid which flows into the 1st branch piping side, and the liquid which flows into the 2nd branch piping side by changing the pressure in a piping tank.
In the liquid mixing apparatus of the present invention, a branch pipe tank comprising a first branch pipe and a second branch pipe branched from a mixed liquid pipe, a pressure adjustable container connected to an outlet of the first branch pipe, and a branch pipe tank And a branch piping tank internal pressure adjusting mechanism for adjusting the internal pressure.
As a result, the liquid flowing in the mixed liquid pipe can be branched into the first branch pipe and the second branch pipe without using a switching valve such as a stop valve.

  In the liquid mixing method and liquid mixing apparatus of the present invention, when a branch pipe tank is used, if the pressure resistance of the branch pipe tank is a low pressure within the range of about −0.1 MPa to about 10,000 Pa, an expensive high pressure resistance Since no tank is used, the manufacturing cost of the liquid mixing device can be reduced. Furthermore, since the pressure in the branch pipe tank is controlled within a low pressure range, the accuracy of pressure control is increased as compared with the case where a high pressure is used.

In the liquid mixing apparatus of the present invention, if a measuring section provided in the liquid mixture pipe is provided for measuring at least one of the liquid A concentration or the liquid B concentration in the liquid mixture, the A in the liquid mixture The mixing ratio of the liquid and the B liquid can be monitored at any time.
In this case, based on the measurement data of the measurement unit, the pressure applied to the A liquid surface in the A liquid tank and the B liquid surface in the B liquid tank so that the mixed liquid has a desired mixing ratio of the A liquid and the B liquid. If a control unit that performs feedback control of pressure is provided, a liquid mixture having a desired mixing ratio can be obtained quickly and automatically.

Moreover, if the A liquid flow meter provided in the A liquid pipe and the B liquid flow meter provided in the B liquid pipe are provided, the mixing ratio of the A liquid and the B liquid in the mixed liquid is monitored at any time. it can.
In this case, based on the measurement data of the A liquid flow meter and the B liquid flow meter, the pressure applied to the A liquid surface in the A liquid tank and the B liquid tank so that the mixed liquid has a desired mixing ratio of A liquid and B liquid. If a control unit that performs feedback control on the pressure applied to the B liquid surface is provided, a liquid mixture having a desired mixing ratio can be obtained quickly and automatically.

  Moreover, if the mixer provided in the liquid mixture piping is provided to mix the liquid A and the liquid B, the liquid A and the liquid B can be reliably mixed by the liquid mixture piping.

Further, is provided with the liquid feed pump provided in the mixing liquid pipe for feeding a liquid mixture, the rapidity and extent of the flow rate control as compared with the case of using gravity to feed liquid increases. Further, by driving the liquid feeding pump, because the solution A tank and B liquid in the tank at a negative pressure, as the liquid A tank pressure regulating mechanism and the liquid B tank pressure regulating mechanism, rather than the pressurizing mechanism, the valve A simple structure that adjusts the pressure in the tank according to the opening can be used.

It is a figure which shows roughly one Example of a liquid mixing apparatus. It is a figure which shows the relationship between the IPA density | concentration and the differential pressure | voltage of A liquid tank and B liquid tank in an example which controlled the mixing ratio with the liquid mixing apparatus of FIG. It is the figure which displayed the theoretical curve in FIG. It is a figure which shows the relationship between the IPA density | concentration and the differential pressure | voltage of A liquid tank and B liquid tank in the other example which controlled the mixing ratio with the liquid mixing apparatus of FIG. It is the figure which displayed the theoretical curve in FIG. It is a figure which shows schematically the other Example of a liquid mixing apparatus. When the ratio of the flow rate of the liquid flowing to the waste liquid pipe side and the flow rate of the liquid flowing to the use point pipe side in the liquid mixing apparatus of FIG. 6 is changed, the flow rate to the use point side and the pressure applied to the waste liquid tank It is a figure which shows a relationship. It is a figure which shows schematically the further another Example of a liquid mixing apparatus. It is a figure which shows schematically the further another Example of a liquid mixing apparatus. It is a figure which shows schematically the further another Example of a liquid mixing apparatus. It is a figure which shows the top view and side view of a mixing part of the Example. It is a top view which shows the flow of the liquid in the mixing part of the Example by the arrow. It is a side view which shows the glass partition plate before joining which comprises the chip | tip of the Example, and two glass plates. It is a schematic block diagram for demonstrating the conventional liquid mixing apparatus. It is a schematic block diagram for demonstrating another conventional liquid mixing apparatus. It is a schematic block diagram for demonstrating another conventional liquid mixing apparatus. It is a schematic block diagram for demonstrating another conventional liquid mixing apparatus. It is a schematic block diagram for demonstrating another conventional liquid mixing apparatus. It is a schematic block diagram for demonstrating another conventional liquid mixing apparatus. It is a schematic block diagram for demonstrating another conventional liquid mixing apparatus.

FIG. 1 is a diagram schematically showing an embodiment of a liquid mixing apparatus.
A liquid tank 1a for storing liquid A and a liquid B tank 1b for storing liquid B are provided. A liquid pipe 3a for sending A liquid stored in A liquid tank 1a, B liquid pipe 3b for sending B liquid stored in B liquid tank 1b, A liquid pipes 3a and B Tees 5 for joining the liquid pipes 3b, and a mixed liquid pipe 7 connected to the teeth 5 for feeding a liquid mixture of A liquid and B liquid are provided.

  A mixer (mixer) 9, a measuring unit 11, and a liquid feed pump 13 are provided in the mixed solution pipe 7 in order from the upstream side. The mixer 9 is for mixing the A liquid and the B liquid. The measuring unit 11 is for measuring at least one of the concentration of solution A or the concentration of solution B in the mixed solution. The liquid feed pump 13 is for feeding the liquid in the pipes 3a, 3b, 7 to the use point. The order in which the mixer 9, the measurement part 11, and the liquid feeding pump 13 are arranged is not specifically limited. However, the mixer 9 is preferably arranged on the upstream side of the measuring unit 11.

The A liquid tank 1a and the B liquid tank 1b are containers whose pressures can be adjusted. The A liquid tank 1a and the B liquid tank 1b do not have to be able to withstand high pressure, and may be any pressure that can control the pressure of ± 2000 Pa (about ± 0.02 kg / cm ² ). The A liquid tank 1a and the B liquid tank 1b are made of, for example, a commercially available polyethylene.

  The A liquid tank 1a is connected to a pressure adjusting pipe 15a for adjusting the pressure in the A liquid tank 1a and an A liquid tank internal pressure adjusting mechanism 17a. The B liquid tank 1b is connected to a pressure adjusting pipe 15b for adjusting the pressure in the B liquid tank 1b and a B liquid tank internal pressure adjusting mechanism 17b. The pressure adjusting mechanisms 17a and 17b are capable of, for example, pressurizing and depressurizing operations. The pressure adjusting mechanisms 17a and 17b adjust the pressure in the tanks 1a and 1b by, for example, air pressure.

  A control unit 19 for controlling the operation of the pressure adjusting mechanisms 17a and 17b is provided. Based on the measurement data of the measurement unit 11, the control unit 19 applies feedback control to the pressure adjusting mechanisms 17a and 17b so that the mixed liquid has a desired mixing ratio of the A liquid and the B liquid.

  In this embodiment, the liquid in the pipes 3a, 3b, 7 is fed to the use point by the liquid feed pump 13. At this time, the pressure adjusting mechanism 17a relatively changes the pressure applied to the A liquid level in the A liquid tank 1a and the pressure applied to the B liquid level in the B liquid tank by the pressure adjusting mechanism 17b, thereby mixing the liquid mixture The mixing ratio of liquid A and liquid B is changed.

  The measurement unit 11 measures the concentration of solution A and / or the concentration of solution B after passing through the mixer 9. Based on the measurement data of the measurement unit 11, the pressure adjustment mechanisms 17 a and 17 b are controlled by the control unit 19 so that a liquid mixture having a desired mixing ratio is obtained. The flow rate of the liquid mixture to the use point can be made variable by the operation rate of the liquid feed pump 13. The mixed liquid flow rate can also be changed by changing the pressure applied to the A liquid surface and the B liquid surface in the tanks 1a and 1b by the pressure adjusting mechanisms 17a and 17b.

  In the control method of the mixing ratio of the liquid A and the liquid B, the control unit 19 determines from the measurement data of the measuring unit 11 whether the mixing ratio of the currently flowing liquid mixture is higher or lower than a set value. . For example, when the ratio of the A liquid is high, the pressurization to the A liquid surface in the A liquid tank 1a is lowered, or the pressurization to the B liquid surface in the B liquid tank 1b is increased. The operation of the pressure adjusting mechanisms 17a and 17b is performed by transmitting an electrical signal from the control unit 19 to the pressure adjusting mechanisms 17a and 17b. For example, after several seconds, the result of this action is reflected in the measurement data of the measurement unit 11. When the control unit 19 determines that the set mixing ratio has not yet been reached based on the measurement data, the control unit 19 applies pressure to the A liquid surface in the A liquid tank 1a to the pressure adjusting mechanisms 17a and 17b. Is instructed to lower the pressure or increase the pressure on the B liquid level in the B liquid tank b, and when the mixture ratio has already been set, feedback control is performed to instruct the reverse operation.

  Further, in the tanks 1a and 1b, data obtained in advance on the relationship between the change in pressure applied to the liquid level A and the liquid level B and the change in flow rate may be stored in a memory device provided in the control unit 19. Good. The control unit 19 compares the set mixing ratio with the measurement data from the measuring unit 11 to obtain the change in the flow rates of the liquid A and the liquid B necessary to obtain the set mixing ratio, and accordingly The amount of change in pressure applied to the A and B liquid surfaces is calculated. Then, the control unit 19 transmits the pressure change amount to the pressure adjusting mechanisms 17a and 17b by an electric signal. The liquid mixing apparatus of the present invention can also perform such feedforward control.

Next, the result of changing the mixing ratio of the liquid A and the liquid B will be described using the embodiment shown in FIG.
20 L (liter) tanks were used as the A liquid tank 1a and the B liquid tank 1b. Pure water was put into the A liquid tank 1a. The B liquid tank 1b was charged with IPA (isopropyl alcohol) having a concentration of 4.2 wt% (weight percent). Both the liquid A tank 1a and the liquid B tank 1b are containers whose pressure can be adjusted, and are made of polyethylene capable of controlling the pressure of ± 2000 Pa (about ± 0.02 kg / cm ² ).

  The length of the A liquid pipe 3a from the A liquid tank 1a to the teeth 5 is 3 m (meter). The length of the B liquid pipe from the B liquid tank 1b to the teeth 5 is also 3 m. The length of the mixed solution pipe 7 from the teeth 5 to the mixer 9 is 1 cm (centimeter). The length of the mixed solution pipe 7 from the mixer 9 to the measuring unit 11 is 30 cm. The length of the mixed solution pipe 7 from the measurement unit 11 to the pump 13 is 50 cm.

  The pipes are all PFA (perfluoroalkoxy resin) tubes having an outer diameter of 3 mm and an inner diameter of 2 mm. The mixer 9 has a spiral stirrer in the tube and is mixed while the liquid passes through it. The measurement part 11 measures the near-infrared spectrum transmission attenuation factor of a liquid. The liquid feed pump 13 is a tube ironing pump. The flow rate of the liquid feed pump 13 is 10 cc / min. The temperature condition is 25 ° C.

  Table 1 is a table showing the relationship between the pressure to the liquid A tank, the pressure to the liquid B tank, and the IPA concentration. The negative value of the pressure represents a negative pressure with respect to the atmospheric pressure.

  FIG. 2 is a graph of Table 1, showing the relationship between the IPA concentration and the differential pressure between the liquid A tank and the liquid B tank. The vertical axis represents the IPA concentration (wt%) that is the output value of the measurement unit. The horizontal axis is the differential pressure (Pa). The differential pressure is (pressure to the B liquid tank−pressure to the A liquid tank).

From these results, it can be seen that a result almost correlated with the differential pressure is obtained. By controlling the differential pressure, the IPA concentration can be controlled.
FIG. 3 is a diagram showing the theoretical curve in FIG.
As shown in FIG. 3, it is divided into a liquid A saturation region, a proportional region, and a liquid B saturation region. If only the liquid A (pure water) is desired to flow through the mixed liquid flow path 7, the differential pressure may be set to -1200 Pa or less in this example. Further, if only the B liquid (IPA 4.2 wt%) is desired to flow through the mixed liquid flow path 7, the differential pressure may be set to +1200 Pa or more.

Next, the result of changing the mixing ratio of the liquid A and the liquid B under other conditions will be described using the embodiment shown in FIG.
20 L tanks were used as the A liquid tank 1a and the B liquid tank 1b. Pure water was put into the A liquid tank 1a. The B liquid tank 1b was charged with IPA having a concentration of 1 wt%. Both the liquid A tank 1a and the liquid B tank 1b are containers whose pressure can be adjusted, and are made of polyethylene capable of controlling the pressure of ± 2000 Pa (about ± 0.02 kg / cm ² ).

  The length of the A liquid pipe 3a from the A liquid tank 1a to the teeth 5 is 0.8 m. The length of the B liquid pipe from the B liquid tank 1b to the teeth 5 is 0.8 m. The length of the mixed solution pipe 7 from the teeth 5 to the mixer 9 is 1 cm. The length of the mixed solution pipe 7 from the mixer 9 to the measuring unit 11 is 30 cm. The length of the mixed solution pipe 7 from the measurement unit 11 to the pump 13 is 50 cm.

  The A liquid pipe 3a and the mixed liquid pipe 7 are PFA tubes having an outer diameter of 3 mm and an inner diameter of 2 mm. The B liquid pipe 3b is a PFA tube having an outer diameter of 2 mm and an inner diameter of 1 mm. The mixer 9 has a spiral stirrer in the tube and is mixed while the liquid passes through it. The measurement part 11 measures the near-infrared spectrum transmission attenuation factor of a liquid. The liquid feed pump 13 is a tube ironing pump. The flow rate of the liquid feed pump 13 is 10 cc / min. The temperature condition is 25 ° C.

  Table 2 is a table showing the relationship between the pressure to the liquid A tank, the pressure to the liquid B tank, and the IPA concentration. The negative value of the pressure represents a negative pressure with respect to the atmospheric pressure.

  FIG. 4 is a graph of Table 2, showing the relationship between the IPA concentration and the differential pressure between the liquid A tank and the liquid B tank. The vertical axis represents the IPA concentration (wt%) that is the output value of the measurement unit. The horizontal axis is the differential pressure (Pa). The differential pressure is (pressure to the B liquid tank−pressure to the A liquid tank).

  From these results, it can be seen that the results are almost correlated with the liquid level difference. By controlling the differential pressure, the IPA concentration can be controlled from 0.01 wt% to around 0.035 wt%. This is an example in which the dilution rate can be about 30 to 100 times.

FIG. 5 is a diagram showing the theoretical curve shown in FIG.
As shown in FIG. 5, it is divided into a liquid A saturation region and a proportional region. If only the liquid A (pure water) is desired to flow through the mixed liquid pipe 7, the differential pressure may be set to −1000 Pa or less in this example.
In this example, in order to obtain the B liquid saturation region, it is necessary to apply an extraordinary pressure to the B liquid tank 1b. Since it is higher than the pressure resistance of the B liquid tank 1b, there is no data. Can be easily estimated.

  I want to send a liquid mixture with the desired concentration to the use point, but at the time of starting up the device, the control to the mixed concentration will inevitably become a transitional period, so the liquid that does not have the desired concentration will go toward the use point. Become. Therefore, a tease is connected to the outlet of the mixed liquid pipe, and a pipe connected to the use point and a pipe connected to the waste liquid tank are connected to the tease so that liquids other than the desired concentration are directed toward the waste liquid tank. It is preferable to determine whether or not the mixed solution has a desired concentration ratio by the measurement unit.

FIG. 6 is a diagram schematically showing another embodiment of the liquid mixing apparatus. The same parts as those in FIG.
In this embodiment, compared with the embodiment shown in FIG. 1, teeth 21, waste liquid pipe (first branch pipe) 23, use point pipe (second branch pipe) 25, waste liquid tank (branch pipe tank) 27, A pressure adjusting pipe 29 and a waste tank internal pressure adjusting mechanism 31 are further provided.

  Teeth 21 is connected to the outlet of mixed liquid pipe 7. The waste liquid pipe 23 and the use point pipe 25 are connected to the teeth 21. The outlet of the waste liquid pipe 23 is connected to a waste liquid tank 27. The outlet of the use point pipe 25 is led to the use point.

The waste liquid tank 27 is a container whose pressure can be adjusted. The pressure resistance of the waste liquid tank 27 is, for example, −15000 Pa to 15000 Pa. The material of the waste liquid tank 27 is, for example, polyethylene.
The waste liquid tank 27 is connected to a pressure adjusting pipe 29 for adjusting the pressure in the waste liquid tank 27 and the A liquid tank internal pressure adjusting mechanism 31. The pressure adjustment mechanism 31 is capable of, for example, pressurization and decompression operations. The waste liquid tank pressure adjusting mechanism 31 adjusts the pressure in the waste liquid tank 27 by, for example, air pressure. The operation of the pressure adjustment mechanism 31 is controlled by the control unit 19.

  Further, in this embodiment, compared with the embodiment shown in FIG. 1, the liquid feed pump 13 is arranged on the upstream side of the measuring unit 11 in the mixed liquid pipe 7, but the mixer 9, the measuring unit 11, The order in which the liquid pumps 13 are arranged is not particularly limited. However, also here, the mixer 9 is preferably arranged on the upstream side of the measuring unit 11.

By changing the pressure in the waste liquid tank 27 by the operation of the pressure adjusting mechanism 31, the ratio of the flow rate of the liquid flowing from the teeth 21 to the waste liquid pipe 23 side and the flow rate of the liquid flowing to the use point pipe 25 side can be changed. it can.
Table 3 is a table showing the relationship between the flow rate to the use point side and the pressure applied to the waste liquid tank.

FIG. 7 is a graph of Table 3.
If the pressure in the waste liquid tank 31 is lower than −2000 Pa, all of the liquid in the mixed liquid pipe 7 is directed from the teeth 21 to the waste liquid tank 31 through the waste liquid pipe 23.
Further, if the pressure in the waste liquid tank 31 is set to 2000 Pa or more, all the liquid in the mixed liquid pipe 7 is directed from the teeth 21 to the use point side through the use point pipe 25.
When the pressure by the pump 13 is 10,000 Pa and the pressure of the waste liquid tank 31 is 10,000 Pa or more at the location of the teeth 21, the air pressure applied to the waste liquid tank 31 through the pressure adjusting pipe 29 flows back through the waste liquid pipe 23. Go to the point of use.

  From this data, by switching the pressure of the waste liquid tank 31 between a value lower than −2000 Pa and a value not lower than 2000 Pa and not higher than 10,000 Pa, it is possible to control on / off of the flow rate toward the use point.

When the liquid mixture flowing in the liquid mixture pipe 7 does not have a desired concentration, the pressure in the waste liquid tank 31 is controlled to −2000 Pa or less by the control unit 19 so that the liquid mixture does not go to the use point. When the mixed liquid flowing in the mixed liquid pipe 7 has a desired concentration, the pressure in the waste liquid tank 31 is set to a value of 2000 Pa or more and 10,000 Pa or less, and all the mixed liquid is directed to the use point side.
When the flow rate adjustment in the use point pipe 25 is quickly performed, the pump 13 may not be controlled, but may be controlled by actively using the proportional area of FIG.

8 and 9 are diagrams schematically showing still other embodiments of the liquid mixing apparatus, respectively.
The embodiment of FIG. 8 is different from the embodiment of FIG. 1 in the embodiment of FIG. 9, and the embodiment of FIG. 9 is different from the embodiment of FIG. The liquid pipe 3b is provided with a B liquid flow meter 33b.
In these embodiments, the mixing ratio in the mixed liquid can be obtained by calculation based on the indication values of the flow meters 33a and 33b. The control unit 19 controls the operation of the pressure adjusting mechanisms 17a and 17b based on the indication values of the flow meters 33a and 33b so that a desired mixing ratio is obtained.

Next, another embodiment will be described with reference to FIGS.
A direct methanol fuel cell (DMFC) is a small fuel cell for portable devices. The fuel supply of the DMFC type fuel cell is performed with a methanol aqueous solution having a methanol concentration of 3 to 5 wt%. If the methanol concentration is high, a crossover phenomenon occurs in which unreacted methanol at the fuel electrode permeates the electrolyte membrane and reaches the air electrode, resulting in a problem that power generation efficiency decreases. On the other hand, if the methanol concentration is low, the power generation efficiency decreases. Therefore, it is desired to always supply an optimal methanol concentration. Further, if methanol having a high concentration can be used after being diluted to an optimum concentration with water, the volume of methanol fuel can be reduced and the size can be further reduced.

  FIG. 10 is a schematic view for explaining the configuration of the liquid feeding mechanism used in this embodiment. Parts having the same functions as those in FIGS. 1 and 6 are denoted by the same reference numerals.

A liquid tank 1a containing methanol having a concentration of 30% and a liquid B tank 1b containing water are provided.
One end of the A liquid pipe 3a is connected to the A liquid tank 1a containing methanol. The other end of the A liquid pipe 3 a is connected to the mixing unit 35.
One end of the B liquid pipe 3b is connected to the B liquid tank 1b containing water. The other end of the B liquid pipe 3 b is connected to the mixing unit 35. Also connected to the mixing unit 35 are a use point pipe 25 for flowing a diluted methanol having a desired concentration mixed with methanol and water from the pipes 3a and 3b, and a waste liquid pipe 23 for flowing a diluted methanol having a desired concentration. Yes. The use point pipe 25 is provided with a pump 13.

FIG. 11 is a diagram showing a plan view and a side view of the mixing section of the apparatus shown in FIG. In FIG. 11, a pipe formed inside the chip is shown in a transparent manner.
The mixing unit 35 is used to connect the chip 37 having a pipe formed therein by etching of glass, a metal frame 39 for supporting the chip 37, and the pipes 3a, 3b, 23, and 25 to the chip 37. Joints 41, 43, 45, and 47 are provided. The chip 37 is a microfluidic device.

  The planar size of the chip 37 is 12.5 mm × 39 mm, and the thickness is 2.2 mm. The frame 39 has an outer peripheral plane size of 19 mm × 46 mm, an inner peripheral plane size of 13 mm × 40 mm, and a thickness of 4.2 mm. Joints 41, 43, 45, 47 are inserted into the frame portion 39 with screws. The tip 37 disposed inside the frame portion 39 is fixed by being pressed by joints 41, 43, 45, 47. The tip 37 is provided with a tapered concave portion connected to the pipe inside the tip 37 at a position corresponding to the joints 41, 43, 45, 47 on the side surface. The tips of the joints 41, 43, 45, 47 are inserted into the recesses on the side surface of the chip 37, thereby sealing the piping and preventing liquid leakage.

The piping pattern inside the chip 37 will be described.
An in-chip A liquid pipe 49a connected to the A liquid pipe 3a and an in-chip B liquid pipe 49b to which the B liquid pipe 3b is connected are provided. The pipes 49 a and 49 b are merged on the downstream side and connected to the in-chip mixed liquid pipe 51. A mixing unit (mixer) 53 is provided on the downstream side of the in-chip mixed solution pipe 51. The in-chip mixed solution pipe 51 is provided with a sensor unit 55 on the downstream side of the mixing unit 53. The sensor unit 55 is a small space used for measuring the methanol concentration after mixing.

  An in-chip waste liquid pipe 57 and an in-chip use point pipe 59 in which the in-chip mixed liquid pipe 51 is branched on the downstream side of the sensor unit 55 are provided. The in-chip waste liquid pipe 57 is connected to the waste liquid pipe 23. The in-chip use point pipe 59 is connected to the use point pipe 25.

FIG. 12 is a plan view showing the flow of liquid in the mixing unit 53 with arrows.
The mixing unit 53 includes two wide portions 61 and 63. The upstream wide portion 61 and the downstream wide portion 63 are connected by two pipes 65 and 67.

  An in-chip mixed solution pipe 51 is connected to the wide portion 61 on the upstream side. A narrow portion 69 of the pipe is provided in the mixed solution pipe 51 in the chip in the vicinity of the wide portion 61. The upstream ends of the two pipes 65 and 67 that connect the wide portions 61 and 63 are connected to the wide portion 61 at the locations adjacent to the narrow portion 69.

  A downstream pipe 71 is connected to the wide portion 63 on the downstream side. The downstream ends of the two pipes 65 and 67 that connect the wide portions 61 and 63 are connected to the wide portion 63 at the positions on both sides of the pipe 71. In the vicinity of the wide part 63, the pipes 65 and 67 are provided with narrow pipe parts 73 and 75, respectively.

The liquid introduced from the in-chip mixed solution pipe 51 to the wide portion 61 through the narrow portion 69 has a high flow velocity at the thin portion 69, and thus a vortex is generated in the wide portion 61 (see arrows). The liquid introduced from the wide portion 61 to the wide portion 63 via the two pipes 65 and 67 connecting the wide portions 61 and 63 and the narrow portions 73 and 75 of the flow path is flow velocity at the narrow portions 73 and 75. As a result, the vortex is generated in the wide portion 63 (see the arrow). These vortices promote liquid mixing.
As shown in FIG. 11, since the mixing unit 53 is provided in two stages, the liquid is completely mixed by repeating the mixing pattern shown in FIG. 12 in two stages.

  As shown in FIG. 13, the chip 37 has a three-layer structure in which a glass partition plate 37a having a uniform thickness in which a through groove for forming a flow path is formed is sandwiched between two glass flat plates 37b and 37c. ing. The glass partition plate 37a has a uniform thickness of 0.2 mm. The glass flat plates 37b and 37c are processed so that only the contact portion with the joint is tapered. The thickness of the glass flat plates 37b and 37c is 1 mm. The through groove in the glass partition plate 37a is formed by an etching technique.

The height of the piping and space formed in the chip 37 is 0.2 mm.
The groove width of the in-chip A liquid pipe 49a is 1 mm. The groove width of the B liquid pipe 49b in the chip is 4 mm. The groove width of the in-chip waste liquid pipe 57 and the groove width of the in-chip use point pipe 59 are both 1 mm.

Returning to FIG. 10, the description of the entire apparatus will be continued.
Similar to the embodiment shown in FIG. 6, pressure adjusting pipes 15a, 15b, 29 and tank pressure adjusting mechanisms 17a, 17b, 31 are provided for the liquid A tank 1a, liquid B tank 1b, and waste liquid tank 27. It has been. A control unit 19 is provided for controlling the operation of the tank pressure adjusting mechanisms 17a, 17b, and 31.

  A measuring unit 77 for measuring the methanol concentration of the liquid in the sensor unit 55 of the mixing unit 35 is provided. The measuring unit 77 measures the methanol concentration by, for example, a method of measuring the near infrared spectrum transmission attenuation rate. The chip 37 is irradiated with light from above, and the transmitted light of the light is received from the opposite surface, and the near-infrared spectrum transmission attenuation factor of the liquid is measured. The measuring unit 77 constantly measures, for example, whether the methanol concentration is 4 wt%, and transmits the signal to the control unit 19.

The control unit 19 controls the operation of the tank pressure adjusting mechanisms 17a, 17b, 31 according to the methanol concentration measured by the measuring unit 77.
When the methanol concentration is higher than 4 wt%, control is performed to reduce the differential pressure obtained by subtracting the pressure applied to the B liquid tank 1b from the pressure applied to the A liquid tank 1a so as to decrease the flow rate on the methanol side. To do. When the methanol concentration is lower than 4 wt%, the reverse control is performed. Under the control of the control unit 19, the tank pressure adjusting mechanisms 17a and 17b control the pressure applied to the liquid level in the tanks 1a and 1b via the pressure adjusting pipes 15a and 15b. This applied pressure is either positive or negative with respect to atmospheric pressure. As the control pressure range, a fine pressure control of ± 200 Pa is sufficient.

  For example, when the pressure control in the tanks 1a and 1b is incomplete and the methanol concentration measured by the measurement unit 77 is out of 4 wt%, the operation of the waste liquid tank pressure adjustment mechanism 31 is controlled by the control unit 19, The inside of the waste liquid tank 27 is depressurized so that the mixed liquid is directed to the waste liquid pipe 23 so as not to flow to the use point pipe 25 side. In this case, since it is pulled by the pump 13 from the use point piping 25 side, it is necessary to pull it at a pressure that exceeds that pressure. For example, at a pressure of 10,000 Pa, the liquid can be prevented from completely going to the use point pipe 25 side.

  As mentioned above, although the Example of this invention was described, material, a shape, arrangement | positioning, a dimension, etc. are examples, This invention is not limited to these, In the range of this invention described in the claim Various changes can be made.

For example, although it described as tees (three-branch joint) by 2 liquid mixing of A liquid and B liquid, what kind of shape may be sufficient if it is a 3 branch path.
In addition, the same applies to the three-liquid mixing of the liquid A, the liquid B, and the liquid C. In that case, a four-branch joint may be used, or a plurality of three-branch joints may be combined.
Three or more liquids can be mixed by a combination of the two liquid mixing methods in this example.
In addition, only an example of bi-directional branching is described with respect to the bifurcation, but it is obvious that the bi-directional bifurcation can be realized even in three or more directions.
Moreover, in the said Example, although the liquid feeding pump 13 is provided, when liquid feeding can be carried out by gravity fall in this invention, a liquid feeding pump is not necessarily required.

1a A liquid tank 1b B liquid tank 3a A liquid pipe 3b B liquid pipe 7 Mixed liquid pipe 9 Mixer (mixer)
DESCRIPTION OF SYMBOLS 11 Measurement part 13 Liquid feed pump 17a A liquid tank internal pressure adjustment mechanism 17b B liquid tank internal pressure adjustment mechanism 19 Control part 23 Waste liquid piping (1st branch piping)
25 Use point piping (second branch piping)
27 Waste liquid tank (first branch piping tank)
31 Pressure adjustment mechanism in waste liquid tank (pressure adjustment mechanism in branch piping tank)
33a A liquid flow meter 33b B liquid flow meter 49a In-chip A liquid pipe 49b In-chip B liquid pipe 51 In-chip mixed liquid pipe 53 Mixing unit (mixer)
57 Chip waste pipe (first branch pipe)
59 In-chip use point piping (second branch piping)
77 Measuring unit

Claims (13)

The A liquid pipe for feeding the A liquid stored in the A liquid tank and the B liquid pipe for feeding the B liquid stored in the B liquid tank are merged and led to the mixed liquid pipe for mixing. In a liquid mixing method for obtaining a liquid mixture in which liquid A and liquid B are mixed at a desired ratio in a liquid pipe,
Using the liquid feeding pumps arranged downstream of the A liquid tank and the B liquid tank as liquid feeding means , the pressure in the A liquid tank and the pressure in the B liquid tank are set in the respective tanks. Make negative pressure relative to the atmospheric pressure
By relatively changing the pressure of the liquid A tank and using a container capable of pressure control as the B liquid tank, the liquid B tank and the pressure of the liquid A in the tank, the ability to feed the solution A A liquid mixing method characterized by controlling the ability to send the B liquid to change the A liquid flow rate and the B liquid flow rate to change the mixing ratio of the A liquid and the B liquid in the mixed liquid. The A liquid tank and the B liquid tank have a pressure resistance in the range of about −0.1 MPa to about 10,000 Pa, and the pressure in the liquid A tank and the pressure in the liquid B tank are within the pressure resistance range. The liquid mixing method according to claim 1, wherein the liquid is controlled. Connecting the first branch pipe and the second branch pipe to the outlet of the mixed liquid pipe;
Connecting a branch pipe tank made of a container capable of adjusting pressure to the outlet of the first branch pipe;
The liquid mixing according to claim 1 or 2 , wherein a flow rate ratio of a liquid flowing to the first branch pipe side and a liquid flowing to the second branch pipe side is changed by changing a pressure in the first branch pipe tank. Method. In claim 3, the breakdown voltage as the first branch pipe tank used as the low voltage in the range of about -0.1MPa~ about 10000 Pa, to control the pressure in the first branch pipe tank within its breakdown voltage The liquid mixing method as described. The A liquid pipe for feeding the A liquid stored in the A liquid tank, the B liquid pipe for feeding the B liquid stored in the B liquid tank, the A liquid pipe and the B liquid pipe are joined together. In a liquid mixing apparatus provided with a mixed liquid pipe,
The A liquid tank and the B liquid tank are containers whose pressure can be adjusted,
A liquid feed pump provided downstream of the liquid A tank and the liquid B tank;
A liquid tank internal pressure adjustment mechanism for adjusting the pressure in the liquid A tank, and a liquid B tank pressure adjustment mechanism for adjusting the pressure in the liquid B tank,
Locations where the pressure in the A liquid tank and the pressure in the B liquid tank are installed in the respective liquid tanks by the liquid feed pump, the pressure adjusting mechanism in the A liquid tank, and the pressure adjusting mechanism in the B liquid tank The pressure in the liquid A tank is adjusted by the pressure adjustment mechanism in the liquid A tank, and the pressure in the liquid B tank is adjusted by the pressure adjustment mechanism in the liquid B tank. The liquid is characterized by changing the mixing ratio of the A liquid and the B liquid in the mixed liquid by controlling the ability to send the A liquid and the ability to send the B liquid by relatively changing the ratio. Mixing equipment. The A liquid tank and the B liquid tank have a low pressure resistance within a range of about −0.1 MPa to about 10,000 Pa,
Wherein A liquid tank pressure adjusting mechanism and the liquid B tank pressure regulating mechanism is a liquid mixture of claim 5 to adjust the pressure of the pressure and the liquid B tank of the liquid A in the tank within the scope of the breakdown voltage apparatus. 7. The liquid mixing apparatus according to claim 5 , further comprising a measuring unit provided in the mixed liquid pipe for measuring at least one of the A liquid concentration and the B liquid concentration in the mixed liquid. A control unit that applies feedback control to the pressure adjustment mechanism in the A liquid tank and the pressure adjustment mechanism in the B liquid tank so that the mixed liquid has a desired mixing ratio of the A liquid and the B liquid based on the measurement data of the measurement unit A liquid mixing apparatus according to claim 7 . The liquid mixing apparatus according to claim 5 or 6 , comprising a liquid A flow meter provided in the liquid A piping and a liquid B flow meter provided in the liquid B piping. Based on the measurement data of the liquid A flow meter and the liquid B flow meter, the pressure adjustment mechanism in the liquid A tank and the pressure adjustment in the liquid B tank so that the liquid mixture has a desired mixing ratio of liquid A and liquid B The liquid mixing apparatus according to claim 9 , further comprising a control unit that applies feedback control to the mechanism. The liquid mixing apparatus according to any one of claims 5 to 10 , further comprising a mixer provided in the mixed liquid pipe for mixing the A liquid and the B liquid. A first branch pipe and a second branch pipe branched from the mixed liquid pipe;
A branch pipe tank composed of a pressure-adjustable container connected to the outlet of the first branch pipe;
The liquid mixing device according to any one of claims 5 to 11 , further comprising a branch piping tank pressure adjusting mechanism for adjusting a pressure in the branch piping tank. The first branch pipe tank has a low pressure resistance within a range of a pressure resistance of about −0.1 MPa to about 10,000 Pa,
The liquid mixing device according to claim 12 , wherein the branch pipe tank pressure adjustment mechanism controls the pressure in the first branch pipe tank within a range of pressure resistance.

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