Mass flow meter and mass flow controller with same

Abstract

A mass flow meter comprises a pipeline body and a sensor. The pipeline body is provided with a main flow channel, a first sensor branch flow channel, a second sensor branch flow channel and a containing chamber; and two ends of the first sensor branch flow channel and the second sensor branch flow channel are respectively communicated with the main flow channel and the accommodating chamber. The sensor is arranged in the containing chamber and connected to the first sensor branch flow channel and the second sensor branch flow channel, so that a part of fluid enters the sensor through the first sensor branch flow channel, and the flow of the fluid is measured. The pipeline body is further provided with a pressure chamber which is communicated with the containing chamber and the main flow channel, so that a part of fluid can enter the pressure chamber, and pressure inside and outside the sensor is consistent. In addition, the invention further provides a mass flow controller with the mass flow meter. The invention can reduce the probability that the sensor is damaged by high-pressure fluid.

Description

Technical Field

[0001] This invention relates to the technical field of detecting and controlling the flow rate of fluids, such as liquids and gases, and more particularly to a mass flow meter that reduces the probability of sensor damage by pressure and a mass flow controller having the mass flow meter. Background Technology

[0002] A mass flow controller (MFC) is a fluid flow measurement and control device that takes into account temperature and pressure. In recent years, it has been widely used to measure and control the flow rate of compressible fluids such as gases and liquids. Generally, the main components of a mass flow controller include a mass flow meter (MFM), a control valve, and a controller. The mass flow meter has a pipeline and a sensor. The pipeline serves functions such as filtering, flow stabilization, and connecting the sensor and the control valve; the sensor monitors the flow rate of the fluid passing through the pipeline and transmits a flow signal to the controller; the controller then controls the control valve based on the flow signal to adjust the flow rate of the fluid exiting the pipeline.

[0003] The most important component of the aforementioned mass flow controller is, obviously, the mass flow meter. Currently, the two most common types of mass flow meters on the market are thermal mass flow meters and Coriolis mass flow meters. Thermal mass flow meters measure flow using the thermal diffusion effect of gases, while Coriolis mass flow meters measure flow based on the Coriolis principle.

[0004] In practice, it has been found that because the pipe and the sensor are made of different materials (usually the pipe is metal and the sensor is plastic), the sensor is often damaged by the high-pressure fluid in the pipe or leaks, causing the sensor to fail to detect the fluid flow rate correctly. Summary of the Invention

[0005] The purpose of this invention is to provide a mass flow meter and a mass flow controller having the mass flow meter, which can reduce the probability of the sensor being damaged by high-pressure fluid.

[0006] To achieve the above objectives and effects, the present invention provides a mass flow meter comprising: a pipeline body having a main channel, a first sensor branch channel, a second sensor branch channel, and a chamber; wherein the two ends of the first sensor branch channel and the second sensor branch channel are respectively connected to the main channel and the chamber; a filter is disposed in the main channel; and a sensor having an inlet nozzle and an outlet nozzle; the sensor is installed in the chamber, with the inlet nozzle connected to the first sensor branch channel and the outlet nozzle connected to the second sensor branch channel, thereby allowing a portion of the fluid passing through the main channel to enter the sensor via the first sensor branch channel and then return to the main channel via the second sensor branch channel, thereby measuring the flow rate of the fluid. The pipeline body further comprises a pressure chamber, which is connected to both the chamber and the main channel, allowing a portion of the fluid passing through the main channel to enter the pressure chamber, resulting in uniform pressure inside and outside the sensor.

[0007] The present invention further provides a mass flow controller, comprising: a pipeline body having a main flow channel, a first sensor branch flow channel, a second sensor branch flow channel, a chamber, a downstream main flow channel, a first valve branch flow channel, and a second valve branch flow channel; wherein, the two ends of the first sensor branch flow channel and the second sensor branch flow channel are respectively connected to the main flow channel and the chamber; one end of the first valve branch flow channel is connected to the main flow channel, and one end of the second valve branch flow channel is connected to the downstream main flow channel; a filter is disposed in the main flow channel; a sensor having an inlet nozzle and an outlet nozzle; the sensor is installed in the chamber, such that the inlet nozzle is connected to the first sensor branch flow channel. The outlet nozzle is connected to the second sensor branch channel; thereby, a portion of the fluid passing through the main channel can enter the sensor via the first sensor branch channel, and then return to the main channel via the second sensor branch channel, thereby detecting the fluid flow rate; and a control valve having a valve inlet and a valve outlet, the control valve being disposed on the pipeline body, with the valve inlet connected to the first valve branch channel and the valve outlet connected to the second valve branch channel; thereby, the fluid in the main channel enters the control valve via the first valve branch channel, and then enters the downstream main channel via the second valve branch channel; the control valve adjusts the flow rate of the fluid flowing out of the valve outlet according to the flow rate detected by the sensor. The pipeline body further includes a pressure chamber and an air passage, the pressure chamber being connected to the container, and the air passage being connected to both the pressure chamber and the main channel, so that a portion of the fluid passing through the main channel enters the pressure chamber via the air passage, causing the pressure inside and outside the sensor to be equalized.

[0008] In one embodiment, the volume of the chamber is larger than that of the sensor, so that a space is created between the sensor and the side wall of the chamber, which forms the pressure chamber.

[0009] In one embodiment, the diameter of the first sensor branch channel is larger than the inlet nozzle of the sensor, so that a space is created between the inlet nozzle and the sidewall of the first sensor branch channel, and this space forms the air channel.

[0010] In one embodiment, an O-ring is provided at the outlet nozzle of the sensor to make the pressure chamber and the branch channel of the second sensor airtight.

[0011] In one embodiment, a cover is further included, which closes the chamber when the sensor is installed in the chamber.

[0012] The following describes preferred embodiments in accordance with the purpose and effects of the present invention, and in conjunction with the accompanying drawings. Attached Figure Description

[0013] Figure 1 This is a perspective view of the first preferred embodiment of the present invention, showing the appearance of the mass flow meter.

[0014] Figure 2 This is an anatomical view of the first preferred embodiment of the present invention.

[0015] Figure 3 This is a combined cross-sectional view of the first preferred embodiment of the present invention.

[0016] Figure 4 yes Figure 3 A magnified view of a portion of the image.

[0017] Figure 5 This is a cross-sectional view of a second preferred embodiment of the present invention, showing a mass flow controller having the mass flow meter. Detailed Implementation

[0018] Please see Figures 1 to 4 As shown, the mass flow meter 1 disclosed in the first preferred embodiment of the present invention includes: a pipeline body 10 and a sensor 12.

[0019] The pipe body 10 is made of metal and includes a main channel 14, a first sensor branch channel 16, a second sensor branch channel 18, and a chamber 20. The main channel 14 has a flow inlet 22 at one end and a flow outlet 24 at the other end. The first sensor branch channel 16 and the second sensor branch channel 18 are connected to the main channel 14 and the chamber 20, respectively, with the first sensor branch channel 16 closer to the flow inlet 22 than the second sensor branch channel 18. A first connector 26 is connected to the flow inlet 22 to introduce fluid into the main channel 14. A second connector 28 is connected to the flow outlet 24 to drain the fluid from the main channel 14. A filter 30 is installed inside the main channel 14 to filter the fluid. The filter 30 is provided with an airtight ring 32, which abuts against the wall of the main channel 14 and is located between the first sensor branch channel 16 and the second sensor branch channel 18, so that some of the fluid will enter the first sensor branch channel 16 from the outside of the filter 30.

[0020] One side of the chamber 20 is open on the outer surface of the pipe body 10. The sensor 12 is installed in the chamber 20 and then fixed to the pipe body with a cap 34 to close the chamber 20. The sensor 12 has an inlet nozzle 36 connected to the first sensor branch channel 16 and an outlet nozzle 38 connected to the second sensor branch channel 18.

[0021] Through the above combination, most of the fluid entering the main channel 14 through the first connector 26 will pass through the filter 30, while a small portion of the fluid will enter the sensor 12 through the first sensor branch channel 16 from the outside of the filter 30, and then return to the main channel 14 through the second sensor branch channel 18. In this way, the sensor 12 can detect the flow rate, pressure, temperature, humidity, etc. of the fluid, and generate a detection signal accordingly.

[0022] The main inventive feature of this invention is that the pipeline body 10 is provided with a pressure chamber 40 and an air passage 42. The pressure chamber 40 is connected to the container 20, and the two ends of the air passage 42 are respectively connected to the pressure chamber 40 and the main flow channel 14, so that a portion of the fluid passing through the main flow channel 14 can enter the pressure chamber 40 through the air passage 42. This allows the pressure inside and outside the sensor 12 to be approximately the same, thereby reducing the probability of the sensor 12 being damaged by the high-pressure fluid entering the sensor 12.

[0023] Please see Figure 4As shown, in the first preferred embodiment, the volume of the chamber 20 is larger than that of the sensor 12. Therefore, when the sensor 12 is installed in the chamber 20, a space is created between the sensor 12 and the side wall of the chamber 20, which forms the pressure chamber 40. In other words, the pressure chamber 40 is a part of the chamber 20, and this part is the space not occupied by the sensor 12. The diameter of the first sensor branch channel 16 is larger than that of the inlet nozzle 36 of the sensor 12, thereby creating a space between the inlet nozzle 36 and the side wall of the first sensor branch channel 16, which forms the air passage 42. Most of the fluid passing through the first sensor branch channel 16 enters the sensor 12 through the inlet nozzle 36, and a small portion enters the pressure chamber 40 through the air passage 42, so that the pressure inside and outside the sensor 12 remains constant. In practice, by simply installing an O-ring 44 on the outlet nozzle 38, the pressure chamber 40 and the second sensor branch channel 18 can be made airtight, while the inlet nozzle 36 can achieve the aforementioned effect without installing an O-ring.

[0024] Please see Figure 5 As shown, the second preferred embodiment of the present invention provides a mass flow controller 2, which includes the mass flow meter 1 disclosed in the first preferred embodiment and a control valve 46.

[0025] As previously described, the mass flow meter 1 includes the pipeline body 10 and the sensor 12. The pipeline body 10 has a main flow channel 14, a chamber 20, a first sensor branch channel 16 and a second sensor branch channel 18, a pressure chamber 40, and an air passage 42. The structure of these components is the same as described above and will not be repeated. The difference is that the pipeline body 10 further includes a downstream main flow channel 48, a first valve branch channel 50, and a second valve branch channel 52. A partition wall 54 separates the main flow channel 14 and the downstream main flow channel 48, preventing them from communicating with each other. The first valve branch channel 50 is located on one side of the partition wall 54, with one end connected to the main flow channel 14. The second valve branch channel 52 is located on the other side of the partition wall 54, with one end connected to the downstream main flow channel 48. In addition, the second connector 28 is instead connected to one end of the downstream main flow channel 48. The control valve 46 has a valve inlet 56 and a valve outlet 58. The control valve 46 is disposed on the pipeline body 10, such that the valve inlet 56 is connected to the first valve branch channel 50 and the valve outlet 58 is connected to the second valve branch channel 52.

[0026] With the above structure, the fluid entering the main channel 14 through the first connector 26 first passes through the filter 30, then enters the control valve 46 through the first valve branch channel 50, then enters the downstream main channel 48 through the second valve branch channel 52, and finally exits through the second connector 28. As mentioned above, a small portion of the fluid enters the sensor 12 through the first sensor branch channel 16 from the outside of the filter 30, causing the sensor 12 to detect the fluid flow rate, generate a detection signal, and transmit it to a processor 60. The processor 60 then controls the control valve 46 according to the detection signal to adjust the flow rate of the fluid discharged from the valve outlet 58 of the control valve 46, so that the fluid in the downstream main channel 48 is adjusted to have a preset flow rate.

[0027] As mentioned above, the pipeline body 10 is also provided with the pressure chamber 40 and the air passage 42, so that a part of the fluid in the main flow channel 14 enters the pressure chamber 40 through the air passage 42, so as to keep the pressure inside and outside the sensor 12 close, thereby reducing the probability of the sensor 12 being damaged by high pressure fluid.

[0028] The above description describes the preferred embodiments of the present invention and the technical principles applied thereto. For those skilled in the art, any obvious changes such as equivalent transformations or simple substitutions based on the technical solutions of the present invention, without departing from the spirit and scope of the present invention, shall fall within the protection scope of the present invention.

Claims

1. A mass flow meter, characterized in that, Includes: A pipeline body includes a main channel, a first sensor branch channel, a second sensor branch channel, and a chamber; wherein the two ends of the first sensor branch channel and the second sensor branch channel are respectively connected to the main channel and the chamber; a filter is disposed in the main channel; and A sensor has an inlet nozzle and an outlet nozzle; the sensor is installed in the chamber such that the inlet nozzle is connected to the first sensor branch channel and the outlet nozzle is connected to the second sensor branch channel, thereby allowing a portion of the fluid passing through the main channel to enter the sensor via the first sensor branch channel and then return to the main channel via the second sensor branch channel, thereby measuring the flow rate of the fluid; The pipeline body is further provided with a pressure chamber and an air passage. The pressure chamber is connected to the container, and the air passage is connected to the pressure chamber and the main flow channel respectively, so that a part of the fluid passing through the main flow channel will enter the pressure chamber through the air passage, causing the pressure inside and outside the sensor to be the same.

2. The mass flow meter as described in claim 1, characterized in that, The volume of the chamber is larger than that of the sensor, so that a space is created between the sensor and the side wall of the chamber, which forms the pressure chamber.

3. The mass flow meter as described in claim 1, characterized in that, The diameter of the first sensor branch channel is larger than the inlet nozzle of the sensor, so that a space is created between the inlet nozzle and the side wall of the first sensor branch channel, and this space forms the air channel.

4. The mass flow meter as described in claim 2, characterized in that, An O-ring is provided at the outlet nozzle of the sensor to make the pressure chamber and the branch channel of the second sensor airtight.

5. The mass flow meter as described in claim 1, characterized in that, It also includes a cover that closes the chamber when the sensor is installed in it.

6. A mass flow controller, characterized in that, Includes: A pipeline body has a main channel, a first sensor branch channel, a second sensor branch channel, a chamber, a downstream main channel, a first valve branch channel, and a second valve branch channel; wherein, the two ends of the first sensor branch channel and the second sensor branch channel are respectively connected to the main channel and the chamber; one end of the first valve branch channel is connected to the main channel, and one end of the second valve branch channel is connected to the downstream main channel; a filter is provided in the main channel; A sensor has an inlet nozzle and an outlet nozzle; the sensor is installed in the chamber such that the inlet nozzle is connected to a first sensor branch channel and the outlet nozzle is connected to a second sensor branch channel; thereby, a portion of the fluid flowing through the main channel can enter the sensor via the first sensor branch channel and then return to the main channel via the second sensor branch channel, thereby detecting the flow rate of the fluid; and A control valve has a valve inlet and a valve outlet. The control valve is disposed on the pipeline body such that the valve inlet is connected to the first valve branch channel and the valve outlet is connected to the second valve branch channel. In this way, the fluid in the main channel enters the control valve from the first valve branch channel and then enters the downstream main channel from the second valve branch channel. The control valve adjusts the flow rate of the fluid flowing out of the valve outlet according to the flow rate detected by the sensor. The pipeline body is further provided with a pressure chamber and an air passage. The pressure chamber is connected to the container, and the air passage is connected to the pressure chamber and the main flow channel respectively, so that a part of the fluid passing through the main flow channel will enter the pressure chamber through the air passage, causing the pressure inside and outside the sensor to be the same.

7. The mass flow controller as described in claim 6, characterized in that, The volume of the chamber is larger than that of the sensor, so that a space is created between the sensor and the side wall of the chamber, which forms the pressure chamber.

8. The mass flow controller as described in claim 6, characterized in that, The diameter of the first sensor branch channel is larger than the inlet nozzle of the sensor, so that a space is created between the inlet nozzle and the side wall of the first sensor branch channel, and this space forms the air channel.

9. The mass flow controller as described in claim 8, characterized in that, An O-ring is provided at the outlet nozzle of the sensor to make the pressure chamber and the branch channel of the second sensor airtight.

10. The mass flow controller as described in claim 6, characterized in that, It also includes a cover that closes the chamber when the sensor is installed in it.

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