The present invention relates generally to a gas-liquid mixing system, and more particularly to a gas-liquid mixing control system and a control method for gas-liquid mixing.
In the high-tech field, gas-liquid mixed fluid with stable concentration is required to manufacture high-tech product parts (e.g., semiconductor chips, display devices, touch panels). Such gas-liquid mixed fluid with stable concentration is usually supplied to a manufacturing machine for the above-mentioned high-tech product parts at a constant pressure and flow.
Generally, an electric control device (such as a mass-flow controller, MFC) is used adjust the pressure and flow of the liquid and gas input to the mixing tank for forming the gas-liquid mixed fluid. Furthermore, another electric control device is used to adjust the pressure and flow of the gas-liquid mixed fluid output to the manufacturing machine. Therefore, conventional control method for gas-liquid mixed fluid needs electric control devices, which causes a great consumption of electric power and becomes a problem of environmental protection.
Moreover, in the above-mentioned control method, the flow of the gas-liquid mixed fluid that the electric control device can supply is subject to restriction (e.g., 6˜8 LPM). Thus, if there are several manufacturing machines that need to supply a large amount of gas-liquid mixed fluid (e.g., 10˜12 LPM), multiple control units for gas-liquid mixed fluid must be connected in parallel to fully supply the required flow of gas-liquid mixed fluid. However, connecting multiple control units in parallel occupies additional space in the plant and consumes a large amount of electric power, which increases the manufacturing cost of the above-mentioned high-tech product parts.
On the other hand, if the flow of the gas-liquid mixed fluid required by the manufacturing machine is low (e.g., 2˜4 LPM), which exceeds the control capability of the electric control devices, concentration ratio and other related parameters of the gas-liquid mixed fluid will be imbalanced, so that the requirements of the above-mentioned manufacturing machine will not be satisfied.
It is known from the above that there are many problems in the existing gas-liquid mixing control system and control method, which still needs to be improved, BRIEF SUMMARY OF THE INVENTION
In view of the above, the primary objective of the present invention is to provide a gas-liquid mixing control system and a control method for gas-liquid mixing, which regulates the output flow of gas-liquid mixed fluid in a non-electric way and can supply flow in a large range (e.g., 2˜16 LPM). In this way, a single gas-liquid mixing control system can meet the flow requirements for both low-flow (2˜4 LPM) and high-flow (10˜14 LPM). Furthermore, the gas-liquid mixing control system and control method in the present invention work in a non-electric way, which can avoid the consumption of power resources and meet the environmental protection requirements of the new-type manufacturing industry.
The present invention provides a gas-liquid mixing control system including a liquid supply unit, a liquid pressure regulating valve, a gas supply unit, a gas pressure regulating valve, a mixing tank, an output pipe, and a non-electric control flow regulator. The liquid supply unit is provided for providing a liquid with a first constant pressure and a first flow; the liquid pressure regulating valve communicates with the liquid supply unit for keeping the liquid at a first constant pressure and a first flow; the gas supply unit is provided for providing a gas with a second constant pressure and a second flow; the gas pressure regulating valve communicates with the gas supply unit for keeping the gas at a second constant pressure and a second flow, wherein the second constant pressure of the gas is higher than the first constant pressure of the liquid; the mixing tank communicates with the liquid pressure regulating valve and the gas pressure regulating valve, wherein the liquid pressure regulating valve is installed between the liquid supply unit and the mixing tank, and the gas pressure regulating valve is installed between the gas supply unit and the mixing tank. The liquid pressure regulating valve and the liquid supply unit input the liquid to the mixing tank with the first constant pressure and the first flow, and the gas pressure regulating valve and the gas supply unit input the gas to the mixing tank with the second constant pressure and the second flow, wherein the liquid and the gas are mixed in the mixing tank to form a mixed fluid; a first end of the output pipe communicates with the mixing tank, wherein the pressure of the mixed fluid in the mixing tank and the output pipe are the same; and a second end of the output pipe communicates with at least one machine, so that the mixed fluid is output from the mixing tank to the at least one machine through the output pipe; the mixed fluid in the first end is provided with a third flow, and the mixed fluid in the second end is provided with a fourth flow; the non-electric control flow regulator communicates with the output pipe, wherein the mixed fluid passing through the non-electric control flow regulator is provided with a fifth flow; wherein the first flow is greater than or equal to at least one of the fourth flow and the fifth flow.
Another objective of the present invention is to provide a control method for gas-liquid mixing, including the steps of:
providing a liquid with a first constant pressure and a first flow into a mixing tank; providing a gas with a second constant pressure and a second flow into the mixing tank, wherein the second constant pressure of the gas is higher than the first constant pressure of the liquid;
mixing the liquid and the gas in the mixing tank to form a mixed fluid; and outputting the mixed fluid from the mixing tank to at least one machine through an output pipe, wherein the pressure of the mixed fluid in the mixing tank and the output pipe are the same; a first end of the output pipe communicates with the mixing tank, and a second end of the output pipe communicates with the at least one machine; the mixed fluid in the first end is provided with a third flow, and the mixed fluid in the second end is provided with a fourth flow; the output pipe communicates with a non-electric control flow regulator, and the mixed fluid passing through the non-electric control flow regulator is provided with a fifth flow;
wherein the first flow is greater than or equal to at least one of the fourth flow and the fifth flow.
The effects of the present invention are that, the gas-liquid mixing control system and control method use the non-electric control flow regulator to regulate the output flow of the gas-liquid mixed fluid, and can supply flow in a large range (e.g., 2˜16 LPM). In this way, a single gas-liquid mixing control system can meet the flow requirements for both low-flow (2˜4 LPM) and high-flow (10˜14 LPM). Furthermore, the gas-liquid mixing control system and control method in the present invention work in a non-electric way, which can avoid the consumption of power resources and meet the environmental protection requirements of the new-type manufacturing industry.
The present invention will be best understood by referring to the following detailed description of some illustrative embodiments in conjunction with the accompanying drawings, in which
In this embodiment, the liquid supply unit 10 is used to provide a liquid with a first constant pressure and a first flow (such as water), and the gas supply unit 20 is used to provide a gas with a second constant pressure and a second flow (such as carbon dioxide).
In
In this embodiment, the liquid pressure regulating valve 12 includes a mechanical pressure flow meter for testing the pressure and the flow of the liquid output from the liquid supply unit 10 and the input first flow F1 of the liquid; the gas supply unit 20 also includes a mechanical pressure flow meter for testing the pressure and the flow of the gas output from the gas supply unit 20. In addition, the liquid supply flow is at L/min level, while the gas supply flow is at mL/min level, wherein the difference is more than a thousand times. Moreover, the gas will be dissolved in the liquid, and only the excess part of the gas will be discharged by a venting device 32, so that a third flow F3 of the mixed fluid in the mixing tank 30 and a first end 40a of the output pipe 40 is almost the same as the first flow F1 of the inputting liquid. In other words, the first flow F1 is greater than or equal to 1000 times the second flow, and thus the third flow F3 of the mixed fluid which is mixed by the liquid and the gas is approximately equal to the first flow F1. In this embodiment, the second constant pressure of the gas is greater than the first constant pressure of the liquid.
In
In
In the embodiment of the present invention, the first flow F1 is greater than the sum of the fourth flow F4 and the fifth flow F5. That is, if F1=16 LPM, F4=10 LPM, and F5=5.5 LPM.
In the embodiment of the present invention, the first flow F1 is equal to the sum of the fourth flow F4 and the fifth flow F5. That is, if F1=16 LPM, F4=6 LPM, and F5=10 LPM.
In the embodiment of the present invention, the first flow F1 is a fixed value which is preset to 16 LPM (but this is not a limitation, and the value can be adjusted according to actual needs). In addition, if the first flow F1 is greater than the fourth flow F4, the difference between the first flow F1 and the fourth flow F4 is discharged by the non-electric control flow regulator 50 which can be a mechanical valve, such as a back pressure valve. The principle of operation of the back pressure valve 50 is that, the fluid enters the back pressure valve 50 from an inlet and is blocked by a diaphragm, and then exerts an upward pressure on the diaphragm. When the pressure is high enough, a spring is compressed, and the fluid pushes up the diaphragm to form a channel, so that the fluid can flow out from an outlet of the back pressure valve 50. If the fluid pressure is not high enough, which forms a built-up pressure, the fluid pressure in the inlet will rise; until the pressure rises to the preset pressure of the back pressure valve, the fluid will push up the diaphragm to form a passage for being discharged. The pressure of the fluid changes when the fluid flow changes, which then changes the opening size of the diaphragm, so as to automatically regulate the fifth flow FS.
When the pressure of the pipes or the device container are unstable, the back pressure valve can maintain the required pressure of the pipes. In other words, in the gas-liquid mixing control system, stabilizing the pressure of the mixing tank is a key factor to control the concentration of the mixed fluid. In the general factory water supply system, the relationship between flow and the pressure is shown in
In the preferred embodiment, the back pressure valve (i.e., the non-electric control flow regulator 50) functions in the gas-liquid mixing control system 1. When the flow required by the rear-end machine A, B, C, D becomes smaller, the pressure inside the mixing tank 30 and the output pipe 40 rise; when the pressure exceeds the preset pressure of the back pressure valve 50, the back pressure valve 50 starts to relieve pressure, wherein the mixed fluid is discharged from the back pressure valve 50 which controls the discharged flow of the mixed fluid to maintain the internal pressure of the mixing tank 30 and the output pipe 40. On the other hand, when the flow required by the rear-end machine A, B, C, D becomes higher, the pressure inside the mixing tank 30 and the output pipe 40 decrease; when the pressure is lower than the preset pressure of the back pressure valve 50, the opening size of the back pressure valve 50 becomes smaller, so that the flow of the mixed fluid discharged from the back pressure valve 50 decreases, which gradually increases the flow of the mixed fluid supplied to the rear-end machine A, B, C, D. Even more, when the flow required by the rear-end machine A, B, C, D becomes higher, and the pressure inside the mixing tank 30 and the output pipe 40 decrease to below the preset pressure of the back pressure valve 50, the back pressure valve 50 closes, so that the flow of the mixed fluid discharged from the back pressure valve 50 becomes 0, and total flow of the mixed fluid is supplied to the rear-end machine A, B, C, D. The abovementioned gas-liquid mixing control system and the control method can stable the internal pressure of the mixing tank 30 and the output pipe 40 to firmly maintain the mixing ratio and concentration of the gas and the liquid, and to supply the rear-end machine A, B, C, D with stable use flow.
In the preferred embodiment, the difference between the first flow F1 and the fourth flow F4 is greater than or equal to the fifth flow F5. For example, if only the machine A requires mixed fluid, the fourth flow F4 may be only 2 LPM; when the flow of the liquid input to the mixing tank is 16 LPM, the third flow F3 output from the mixing tank 30 is 16 LPM, and the extra 14 LPM is discharged by the non-electric control flow regulator 50. Additionally, if all the machines A, B, C, D require mixed fluid, the fourth flow F4 is 12 LPM; when the flow of the liquid input to the mixing tank is 16 LPM, the third flow F3 output from the mixing tank 30 is 16 LPM, and the extra 4 LPM is discharged by the non-electric control flow regulator 50.
In
In
In
In the preferred embodiment, the non-electric control flow regulator 50 is a mechanical valve which doesn't use electric power. That is, the mechanical valve needs no electric power for control, which can avoid the consumption of power resources and meet the environmental protection requirements of the new-type manufacturing industry.
In
As illustrated in
As shown in
As described above, the gas-liquid mixing control system of the preferred embodiment uses the back pressure valve to improve the past adverse effects on semiconductor product yield, which caused from the unstable concentration of the mixed fluid due to the dramatic pressure changes in the mixing tank under low flow condition. Compared with the conventional gas-liquid mixing system, the gas-liquid mixing control system of the present invention can maintain a constant pressure value of the mixing tank 30 and a fixed total flow of the mixed fluid regardless of the usage amount of the mixed fluid by the device (machine) in order to maintain the high stability of the mixed fluid concentration, and thereby to significantly improve the yield of semiconductor products. In the preferred embodiment, under the condition of a low flow of the mixed fluid (e.g., the usage amount by the device (machine) is below 20 LPM), the gas-liquid mixing control system can maintain a constant pressure value of the mixing tank 30 and a fixed total flow of the mixed fluid, so as to maintain the high stability of the mixed fluid concentration, and thus to significantly improve the yield of semiconductor products as shown in
As depicted in
Step S02: provide the liquid with the first constant pressure and the first flow F1 in the mixing tank;
Step S04: provide the gas with the second constant pressure and the second flow in the mixing tank, wherein the second constant pressure of the gas is higher than the first constant pressure of the liquid;
Step S06: mix the liquid and the gas in the mixing tank 30 to form a mixed fluid;
Step S08: output the mixed fluid from the mixing tank 30 to at least one machine A, B, C, D through the output pipe 40, wherein the pressure of the mixed fluid in the mixing tank 30 and the output pipe 40 are the same; the first end 40a of the output pipe 40 communicates with the mixing tank 30, and the second end 40b thereof communicates with the machine A, B, C, D; the mixed fluid in the first end 40a of the output pipe 40 is provided with the third flow F3, and the mixed fluid in the second end 40b of the output pipe 40 is provided with the fourth flow F4; the output pipe 40 communicates with the non-electric control flow regulator 50, and the mixed fluid passing through the non-electric control flow regulator 50 is provided with the fifth flow F5, wherein the third flow F3 is greater than or equal to the fourth flow F4 and the fifth flow F5.
In the preferred embodiment, the first flow F1 is greater than or equal to 1000 times the second flow, and the third flow F3 is approximately equal to the first flow F1. Moreover, the first flow F1 is greater than the sum of the fourth flow F4 and the fifth flow F5. In another preferred embodiment, the first flow F1 is equal to the sum of the fourth flow F4 and the fifth flow F5.
In the embodiment of the present invention, the first flow F1 is equal to the third flow F3 which is a fixed value; when the third flow F3 is greater than the fourth flow F4, the difference between the third flow F3 and the fourth flow F4 is discharged by the non-electric control flow regulator 50. In the embodiment, the difference between the third flow F3 and the fourth flow F4 is equal to the fifth flow F5.
In the embodiment of the present invention, the mixing tank 30 includes a gas dispersion device 34 located in the mixing tank 30 for dispersing the gas into the liquid to form the mixed fluid. The non-electric control flow regulator 50 is a mechanical valve which can be a back pressure valve with a purely physical structure that does not require electric power. That is, the mechanical valve needs no electric power for control, which can avoid the consumption of power resources and meet the environmental protection requirements of the new-type manufacturing industry.
With the design in the embodiment of the present invention, the gas-liquid mixing control system and control method use the non-electric control flow regulator to control the output flow of the gas-liquid mixed fluid, and can supply flow in a large range (e.g., 2˜16 LPM). In this way, a single gas-liquid mixing control system can meet the flow requirements of the gas-liquid mixed fluid for both low-flow (2˜4 LPM) and high-flow (10˜14 LPM). Furthermore, the gas-liquid mixing control system and control method in the present invention work in a non-electric way, which can avoid the consumption of power resources and meet the environmental protection requirements of the new-type manufacturing industry.
The embodiments described above are only preferred embodiments of the present invention. All equivalent structures and methods which employ the concepts disclosed in this specification and the appended claims should fall within the scope of the present invention.
Number | Date | Country | Kind |
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108137101 | Oct 2019 | TW | national |
109127934 | Aug 2020 | TW | national |