CN101451876A - Liquid level sensing device with self-diagnosis function and self-diagnosis method thereof - Google Patents

Abstract

A liquid level sensing device with a self-diagnosis function and a self-diagnosis method thereof are suitable for sensing the liquid level in a storage tank. The liquid level sensing device includes a lifting device, a separation tank and a liquid level sensor. The separation tank is arranged on the lifting device and is connected to the storage tank. The liquid level sensor is arranged inside the separation tank. The liquid level sensing device with a self-diagnosis function proposed by the present invention uses the principle of a connecting pipe to perform self-diagnosis. Therefore, when performing self-diagnosis on the liquid level sensor, it is not necessary to extract the liquid in the storage tank, so that it will not cause waste of materials and environmental pollution, and can effectively reduce production costs; the corresponding self-diagnosis method is quite convenient in operation, and can greatly reduce the inspection time of the liquid level sensor.

Description

Liquid level sensing device with self-diagnosis function and self-diagnosis method thereof

technical field

The present invention relates to a liquid level sensing device, and in particular to a liquid level sensing device with a self-diagnosing function and a self-diagnosing method thereof.

Background technique

In the known various manufacturing processes, various liquids are often used for different processes, and these liquids are stored in storage tanks. However, when these liquids are used up without being noticed, the process often fails and the yield decreases.

Taking the photolithography process of the semiconductor manufacturing process as an example, before coating the photoresist layer on the semiconductor substrate, hexamethyldisilazane (HMDS) will be sprayed on the semiconductor substrate to increase the photoresist layer and The adhesive force between the semiconductor substrates can prevent the photoresist layer from collapsing.

However, when the HMDS in the storage tank is used up without detection, the formed photoresist layer will not be easily adhered to the semiconductor substrate, causing the photoresist layer to collapse, thereby reducing the yield. Therefore, a liquid level sensor will be provided in the storage tank to ensure that there is a safe stock of HMDS in the storage tank.

FIG. 1 is a schematic diagram of a known storage tank equipped with a liquid level sensor.

Referring to FIG. 1 , there is an optical fiber liquid level sensor 102 in the storage tank 100 , and the optical fiber liquid level sensor 102 has three sensing points H/H, H/L, and L/L from bottom to top. Generally speaking, if the safe stock of liquid in the storage tank 100 is set between the sensing point H/H and the sensing point H/L, it will replenish when it is lower than the sensing point H/L until the storage tank The liquid in 100 is up to the safe stock. Sensing point H/H prevents the 100% liquid in the storage tank from exceeding the safety stock. In addition, when the function of the sensing point H/L fails, the sensing point L/L can be used as a backup sensing point to ensure that the liquid in the storage tank 100 will not be exhausted. However, when the sensing points H/L and L/L fail at the same time, it will lead to a fabrication failure.

Therefore, in the known technology, it is regularly checked whether the function of the optical fiber liquid level sensor 102 is normal. However, when checking whether the sensing points H/H, H/L, and L/L of the optical fiber liquid level sensor 102 are normal, the liquid in the storage tank 100 will be extracted first to obtain the liquid below the sensing point L/L. Check the liquid level, and then re-inject new liquid to check whether the functions of the sensing points L/L, H/L, and H/H are normal.

However, in the above-mentioned method of checking whether the function of the optical fiber liquid level sensor 102 is normal, the operation of pumping out the liquid and refilling the new liquid in the storage tank 100 is quite time-consuming. In addition, the pumped liquid will be discarded, resulting in waste of materials and increasing production costs. In addition, when the extracted liquid is a volatile liquid such as HMDS, it will pollute the environment.

Contents of the invention

In view of this, the technical problem to be solved by the present invention is: to provide a liquid level sensing device with self-diagnosis function, which can effectively reduce the production cost.

Another technical problem to be solved by the present invention is to provide a self-diagnosing method of a liquid level sensing device with a self-diagnosing function, which can quickly check whether the function of the liquid level sensor is normal.

The present invention first proposes a liquid level sensing device with self-diagnosis function, which is suitable for sensing the liquid level in the storage tank. The liquid level sensing device includes a lifting device, a separation tank and a liquid level sensor; the separation tank is arranged on the lifting device The device is connected with the storage tank, and the liquid level sensor is arranged inside the separation tank.

According to a preferred embodiment of the present invention, in the aforementioned liquid level sensing device with self-diagnosis function, the lifting device is, for example, a lifting frame.

According to a preferred embodiment of the present invention, in the aforementioned liquid level sensing device with self-diagnosis function, the volume of the separation tank is smaller than the volume of the storage tank.

According to a preferred embodiment of the present invention, in the above-mentioned liquid level sensing device with self-diagnosis function, the separation tank is, for example, a closed tank.

According to a preferred embodiment of the present invention, the above liquid level sensing device with self-diagnosis function further includes a first communication pipe and a second communication pipe. The first communication pipe communicates with the bottom of the separation tank and the bottom of the storage tank. The second communication pipe communicates with the top of the separation tank and the top of the storage tank.

According to a preferred embodiment of the present invention, in the aforementioned liquid level sensing device with self-diagnosis function, the separation tank is, for example, an open tank.

According to a preferred embodiment of the present invention, the above liquid level sensing device with self-diagnosis function further includes a first communication pipe. The first communication pipe communicates with the bottom of the separation tank and the bottom of the storage tank.

According to a preferred embodiment of the present invention, in the above-mentioned liquid level sensing device with self-diagnosis function, the liquid level sensor is, for example, an optical fiber liquid level sensor, an electrode type liquid level sensor, a photoelectric liquid level sensor, a float Ball type liquid level sensor, pneumatic liquid level sensor, electrostatic capacity liquid level sensor, float continuous liquid level sensor, ultrasonic liquid level sensor, pressure liquid level sensor or hammer type liquid level sensor.

The present invention also proposes a self-diagnosis method for a liquid level sensing device with a self-diagnosing function, wherein the liquid level sensing device includes a lifting device, a separation tank disposed on the lifting device, and a liquid level sensor disposed inside the separation tank, The separation tank communicates with the storage tank storing the liquid, and the self-diagnosis method of the liquid level sensing device includes the following steps: firstly, using a lifting device to adjust the height of the separation tank so that the liquid level in the separation tank falls to the liquid level The liquid level sensing interval of the sensor; then, observe whether the liquid level sensor sends out a sensing signal, if "Yes", it means that the function of the liquid level sensor is normal, if "No", it means that the function of the liquid level sensor is invalid.

According to a preferred embodiment of the present invention, in the above-mentioned self-diagnosis method of the liquid level sensing device with self-diagnosis function, the liquid level of the liquid in the separation tank has not yet entered the liquid level of the liquid level sensor During the sensing interval, observe whether the liquid level sensor sends out a sensing signal. If "Yes", it means that the function of the liquid level sensor is invalid. If "No", it means that the function of the liquid level sensor is normal.

According to a preferred embodiment of the present invention, in the above-mentioned self-diagnosis method of the liquid level sensing device with self-diagnosis function, the lifting device is, for example, a lifting frame.

According to a preferred embodiment of the present invention, in the above self-diagnosis method of the liquid level sensing device with self-diagnosis function, the volume of the separation tank is smaller than the volume of the storage tank.

According to a preferred embodiment of the present invention, in the above self-diagnosis method of the liquid level sensing device with self-diagnosis function, the separation tank is, for example, a closed tank.

According to a preferred embodiment of the present invention, in the above self-diagnosing method of the liquid level sensing device with self-diagnosing function, the liquid level sensing device further includes a first communication pipe and a second communication pipe. The first communication pipe communicates with the bottom of the separation tank and the bottom of the storage tank. The second communication pipe communicates with the top of the separation tank and the top of the storage tank.

According to a preferred embodiment of the present invention, in the above self-diagnosis method of the liquid level sensing device with self-diagnosis function, the separation tank is, for example, an open tank.

According to a preferred embodiment of the present invention, in the above-mentioned self-diagnosis method of the liquid level sensing device with self-diagnosis function, the liquid level sensing device further includes a first communication pipe. The first communication pipe communicates with the bottom of the separation tank and the bottom of the storage tank.

According to a preferred embodiment of the present invention, in the self-diagnosis method of the above-mentioned liquid level sensing device with self-diagnosis function, the liquid level sensor is, for example, an optical fiber liquid level sensor, an electrode type liquid level sensor, a photoelectric liquid level sensor, etc. Level sensor, float type liquid level sensor, pneumatic liquid level sensor, electrostatic capacity liquid level sensor, float continuous liquid level sensor, ultrasonic liquid level sensor, pressure liquid level sensor or hammer type liquid level sensor.

Based on the above, the liquid level sensing device with self-diagnosis function proposed by the present invention utilizes the principle of a connecting tube to perform self-diagnosis. Therefore, when the self-diagnosis of the liquid level sensor is performed, the liquid in the storage tank does not need to be extracted, so there is no waste of materials and environmental pollution, and the production cost can be effectively reduced.

In addition, using the liquid level sensing device with self-diagnosis function proposed by the present invention can ensure the normal function of the liquid level sensor, make the process go smoothly, and prevent process errors from occurring.

On the other hand, the self-diagnosis method of the liquid level sensing device with self-diagnosis function proposed by the present invention is quite convenient in operation, and can greatly reduce the inspection time of the liquid level sensor.

Description of drawings

FIG. 1 is a schematic diagram of a known storage tank equipped with a liquid level sensor.

FIG. 2 is a schematic diagram of a storage tank configured with a liquid level sensing device according to an embodiment of the present invention.

FIG. 3 to FIG. 5 are schematic diagrams showing the bottom of the separation tank and the bottom of the storage tank in FIG. 2 at different heights.

FIG. 6 is a schematic diagram of a storage tank configured with a liquid level sensing device according to another embodiment of the present invention.

[Description of main component symbols]

100, 300: storage tank

102: Optical fiber liquid level sensor

200, 500: Liquid level sensing device 202: Lifting device

204, 504: separation tank 206: liquid level sensor

208, 210: connecting pipe 400: liquid

Detailed ways

FIG. 2 is a schematic diagram of a storage tank configured with a liquid level sensing device according to an embodiment of the present invention.

Referring to FIG. 2 , the liquid level sensing device 200 with self-diagnostic function is suitable for sensing the liquid level in the storage tank 300 . The material of the storage tank 300 and the stored liquid 400 can be determined according to the requirements of the process, and are not particularly limited here.

The liquid level sensing device 200 includes a lifting device 202 , a separation tank 204 , a liquid level sensor 206 and communication pipes 208 , 210 . The elevating device 202 may be any device as long as it can move vertically, for example, an elevating table.

The separation tank 204 is arranged on the lifting device 202 and communicates with the storage tank 300. Generally, when the liquid level of the liquid 400 in the storage tank 300 is monitored, the lifting device 202 will make the bottom of the separation tank 204 and the bottom of the storage tank 300 located at the same height. When performing self-diagnosis on the liquid level sensor 206 , the height of the separation tank 204 can be adjusted by the lifting device 202 to adjust the liquid level of the liquid 400 in the separation tank 204 .

In this embodiment, the separation tank 204 is, for example, a closed tank, which can be used to store various liquids 400 , and the volatile liquid 400 and the easily polluted liquid 400 are usually stored in a closed tank. When the separation tank 204 is a closed tank body, the separation tank 204 communicates with the storage tank 300 through the communication pipes 208 and 210 . The communication pipe 208 connects the bottom of the separation tank 204 and the bottom of the storage tank 300 , so that the liquid 400 in the separation tank 204 and the storage tank 300 can flow with each other. The connecting pipe 210 communicates with the top of the separation tank 204 and the top of the storage tank 300 to balance the air pressure difference between the separation tank 204 and the storage tank 300 .

In addition, the volume of the separation tank 204 is smaller than that of the storage tank 300 . For example, the height of the separation tank 204 is designed to be the same as the height of the storage tank 300, and the cross-sectional area of the separation tank 204 is designed to be smaller than the cross-sectional area of the storage tank 300, so that the volume of the separation tank 204 is smaller than that of the storage tank 300 volume, but it is not used to limit the height of the separation tank 204 of the present invention.

The liquid level sensor 206 is disposed inside the separation tank 204 for sensing the liquid level of the liquid 400 in the storage tank 300 . The liquid level sensor 206 is not particularly limited as long as it can sense a liquid level. In this embodiment, the liquid level sensor 206 is illustrated as an optical fiber liquid level sensor with three sensing points H/H, H/L, and L/L. In other embodiments, the liquid level sensor 206 can be an electrode type liquid level sensor, a photoelectric liquid level sensor, a float type liquid level sensor, a pneumatic liquid level sensor, a static capacitance liquid level sensor, a float ball continuous liquid level sensor , Ultrasonic liquid level sensor, pressure liquid level sensor or heavy hammer liquid level sensor.

Based on the above, the liquid level sensing device 200 uses the principle of the connecting pipe to adjust the liquid level of the liquid 400 in the separation tank 204 to perform self-diagnosis on the liquid level sensor 206 . Therefore, when the self-diagnosis of the liquid level sensor 206 is performed, the liquid 400 in the storage tank 300 does not need to be extracted, so there is no waste of materials and environmental pollution, and the production cost can be effectively reduced.

In addition, the liquid level sensing device 200 can ensure the normal function of the liquid level sensor 206, so the stored liquid 400 in the storage tank 300 will not be used up without being noticed, which can make the manufacturing process go smoothly and prevent A process error occurs.

FIG. 3 to FIG. 5 are schematic diagrams showing the bottom of the separation tank and the bottom of the storage tank in FIG. 2 at different heights.

Hereinafter, the method for self-diagnosing the liquid level sensor 206 by the liquid level sensing device 200 will be described with reference to FIGS. 2 to 5 .

Please refer to FIG. 2 . Generally, when monitoring the liquid level of the liquid 400 in the storage tank 300 , the lifting device 202 makes the bottom of the separation tank 204 and the bottom of the storage tank 300 at the same height. In this embodiment, the liquid level of the liquid 400 in the safety stock is set between the sensing points H/H and H/L, and the liquid level sensing interval of the sensing point H/H is located at the sensing point H/H Above the position, the liquid level sensing zone of sensing point H/L is located at a position lower than sensing point H/L, while the liquid level sensing zone of sensing point L/L is located at a position lower than sensing point L/L L's position. However, those with ordinary knowledge in this technical field can adjust the liquid level of the safety stock and the liquid level sensing range of the liquid level sensor 206 according to their design requirements.

Then, please refer to FIG. 3 , when diagnosing whether the function of the sensing point H/H is normal, the height of the separation tank 204 will be adjusted by the lifting device 202 so that the bottom of the separation tank 204 is located at a position lower than the bottom of the storage tank 300. The height difference is H1, so that the liquid level of the liquid 400 in the separation tank 204 falls within the liquid level sensing interval of the sensing point H/H. Next, observe whether the liquid level sensor 206 sends out the sensing signal of the sensing point H/H, if "Yes", it means that the function of the sensing point H/H is normal, if "No", it means that the function of the sensing point H/H Failed and needs to be repaired.

In addition, when the liquid level of the liquid 400 in the separation tank 204 has not yet entered the liquid level sensing interval of the sensing point H/H, observe whether the liquid level sensor 206 sends a sensing signal of the sensing point H/H, if "Yes " means that the function of the sensing point H/H is invalid, and if "none" means that the function of the sensing point H/H is normal.

Next, please refer to FIG. 4 . When diagnosing whether the function of the sensing point H/L is normal, the height of the separation tank 204 will be adjusted by the lifting device 202, so that the bottom of the separation tank 204 is located at a position higher than the bottom of the storage tank 300. The height difference between them is H2, so that the liquid level of the liquid 400 in the separation tank 204 falls within the liquid level sensing interval of the sensing point H/L. Next, observe whether the liquid level sensor 206 sends a sensing signal of the sensing point H/L, if "Yes", it means that the function of the sensing point H/L is normal, if "No", it means that the function of the sensing point H/L Failed and needs to be repaired.

In addition, when the liquid level of the liquid 400 in the separation tank 204 has not yet entered the liquid level sensing interval of the sensing point H/L, observe whether the liquid level sensor 206 sends out a sensing signal of the sensing point H/L, if "Yes " means that the function of the sensing point H/L is invalid, and if "none" means that the function of the sensing point H/L is normal.

Afterwards, please refer to FIG. 5 , when diagnosing whether the function of the sensing point L/L is normal, the height of the separation tank 204 will be adjusted by the lifting device 202 so that the bottom of the separation tank 204 is at a position higher than the bottom of the storage tank 300. The height difference is H3, so that the liquid level of the liquid 400 in the separation tank 204 falls within the liquid level sensing interval of the sensing point L/L. Next, observe whether the liquid level sensor 206 sends a sensing signal of the sensing point L/L, if "Yes", it means that the function of the sensing point L/L is normal, if "No", it means that the function of the sensing point L/L Failed and needs to be repaired.

In addition, when the liquid level of the liquid 400 in the separation tank 204 has not yet entered the liquid level sensing interval of the sensing point L/L, observe whether the liquid level sensor 206 sends out a sensing signal of the sensing point L/L, if "Yes " means that the function of the sensing point L/L is invalid, and if "none" means that the function of the sensing point L/L is normal.

It can be seen from the above embodiments that the self-diagnosis method of the liquid level sensing device 200 is quite simple and convenient in operation, so the inspection time of the liquid level sensor 206 can be effectively reduced.

FIG. 6 is a schematic diagram of a storage tank configured with a liquid level sensing device according to another embodiment of the present invention. Wherein, the same components as in FIG. 2 are assigned the same reference numerals and their descriptions are omitted.

Please refer to FIG. 6 , the embodiment disclosed in FIG. 6 is substantially the same as the embodiment disclosed in FIG. 2 , the difference between the two is only that the separation tank 504 of the liquid level sensing device 500 disclosed in FIG. 6 is an open tank. . Therefore, there is no need for the connecting pipe 210 to balance the air pressure difference between the separation tank 504 and the storage tank 300, only the bottom of the separation tank 504 and the storage tank 300 need to be connected by the connecting pipe 208, so that the separation tank 504 and the storage tank 300 The liquids 400 can flow with each other. The functions, advantages and self-diagnosis methods of the liquid level sensing device 500 in FIG. 6 are substantially the same as those of the liquid level sensing device 200 in FIG. 2 , so details are not repeated here.

In summary, the present invention has at least the following advantages:

1. The liquid level sensing device with self-diagnosis function proposed by the present invention will not cause material waste and environmental pollution when performing self-diagnosis on the liquid level sensor, and can effectively reduce production costs.

2. Using the liquid level sensing device with self-diagnosis function proposed by the present invention can make the manufacturing process go smoothly and prevent process errors from occurring.

3. The self-diagnosis method of the liquid level sensing device with self-diagnosis function proposed by the present invention can greatly reduce the inspection time of the liquid level sensor.

Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Anyone skilled in the art can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, this The scope of protection of the invention shall be defined by the scope of the attached patent application.

Claims (11)

1. A liquid level sensing device with self-diagnostic function, suitable for sensing the liquid level in the storage tank, characterized in that, the liquid level sensing device comprises: Lifting device; a separation tank arranged on the lifting device and communicated with the storage tank; and The liquid level sensor is arranged inside the separation tank. 2. The liquid level sensing device with self-diagnosis function as claimed in claim 1, wherein the volume of the separation tank is smaller than the volume of the storage tank. 3. The liquid level sensing device with self-diagnostic function as claimed in claim 1, characterized in that, the liquid level sensing device further comprises: a first communication pipe connecting the bottom of the separation tank with the bottom of the storage tank; and The second connecting pipe communicates with the top of the separation tank and the top of the storage tank. 4. The liquid level sensing device with self-diagnostic function as claimed in claim 1, characterized in that, the liquid level sensing device further comprises a first connecting pipe connecting the bottom of the separation tank with the bottom of the storage tank . 5. The liquid level sensing device with self-diagnosis function as claimed in claim 1, characterized in that, the liquid level sensor comprises an optical fiber liquid level sensor, an electrode type liquid level sensor, a photoelectric liquid level sensor, a float type liquid level sensor Level sensor, pneumatic liquid level sensor, electrostatic capacity liquid level sensor, float continuous liquid level sensor, ultrasonic liquid level sensor, pressure liquid level sensor or hammer liquid level sensor. 6. A self-diagnosis method of a liquid level sensing device with a self-diagnosing function, characterized in that the liquid level sensing device includes a lifting device, a separation tank arranged on the lifting device, and a separation tank arranged inside the separation tank A liquid level sensor, wherein the separation tank communicates with a storage tank storing liquid, the method comprising: Using the lifting device to adjust the height of the separation tank, so that the liquid level of the liquid in the separation tank falls within the liquid level sensing area of the liquid level sensor; and Observe whether the liquid level sensor sends out a sensing signal, if "Yes", it means that the function of the liquid level sensor is normal, if "No", it means that the function of the liquid level sensor is invalid. 7. The self-diagnosing method of the liquid level sensing device with self-diagnosing function as claimed in claim 6, characterized in that, the self-diagnosing method comprises that the liquid level of the liquid in the separation tank has not yet entered the liquid level During the liquid level sensing interval of the sensor, observe whether the liquid level sensor sends out the sensing signal, if "Yes", it means that the function of the liquid level sensor is invalid, if "No", it means that the function of the liquid level sensor is normal. 8. The self-diagnosing method of the liquid level sensing device with self-diagnosing function as claimed in claim 6, wherein the volume of the separation tank is smaller than the volume of the storage tank. 9. The self-diagnosing method of the liquid level sensing device with self-diagnosing function as claimed in claim 6, characterized in that, the liquid level sensing device further comprises: a first communication pipe connecting the bottom of the separation tank with the bottom of the storage tank; and The second connecting pipe communicates with the top of the separation tank and the top of the storage tank. 10. The self-diagnosing method of the liquid level sensing device with self-diagnosing function as claimed in claim 6, characterized in that, the liquid level sensing device further comprises a first communication pipe, which communicates with the bottom of the separation tank and the storage bottom of the tank. 11. The self-diagnosis method of the liquid level sensing device with self-diagnosis function as claimed in claim 6, wherein the liquid level sensor comprises an optical fiber liquid level sensor, an electrode type liquid level sensor, a photoelectric liquid level sensor, Float type liquid level sensor, pneumatic liquid level sensor, electrostatic capacity liquid level sensor, float continuous liquid level sensor, ultrasonic liquid level sensor, pressure liquid level sensor or hammer type liquid level sensor.

Images