JP5213583B2 - Flow measuring device - Google Patents

Description

  The present invention relates to a fluid flow rate measuring device, and more particularly to a flow rate measuring device capable of varying a flow rate measuring area of a differential pressure type flow rate sensor.

  There are various flow sensors such as a rotary flow sensor, a float flow sensor, an ultrasonic flow sensor, a Karman vortex flow sensor, and the like as flow sensors for measuring the flow rate of fluid. The rotary flow sensor and the float type flow sensor have a problem that particles (fine dust) are generated in the flow path when the impeller and the float move in the flow path. Ultrasonic flow rate sensors and Karman vortex flow rate sensors are vulnerable to bubbles generated during the flow of fluid (liquid) and have problems such as variations in accuracy due to fluid disturbance. In particular, it has been difficult to use in environments where high cleanliness is required, such as semiconductor manufacturing, or in the field where foaming fluid is used.

  A differential pressure type flow sensor is known as a flow sensor that solves the above problems. For example, there is known a differential pressure type flow rate sensor configured to detect the back pressure of one pressure receiving portion with one sensor with respect to two pressure receiving portions arranged integrally opposite to each other (see Patent Document 1). In the differential pressure type flow sensor of Patent Document 1, a first diaphragm and a second diaphragm are arranged opposite to each other at both ends of a shaft portion, and a first chamber and an inner side of the second diaphragm are in contact with the inside of the first diaphragm between the two diaphragms. A second chamber in contact with the first chamber, an intermediate partition portion having an intermediate diaphragm partitioning the first chamber and the second chamber, and a load difference sensor disposed on the back surface of the first diaphragm, and formed in the intermediate diaphragm By causing a fluid having a differential pressure to flow through the orifice portion, the load difference sensor detects the back pressure of the first diaphragm as a load difference and measures the flow rate. Therefore, the flow rate sensor is free from the possibility of generating particles in the fluid.

  Currently, when the flow rate is measured using the differential pressure type flow rate sensor, a differential pressure type flow rate sensor corresponding to an assumed flow rate measurement range is arranged in the distribution line. And when changing the piping of the measurement part or changing the measured flow rate outside the flow rate measurement range of the flow sensor, an unexpected pressure fluctuation occurs, so other flow measurement corresponding to the fluctuating pressure It was replaced by a differential pressure type flow sensor with a set range. However, such work is laborious and increases the running cost. For this reason, there is a demand for a differential pressure type flow rate sensor having a large range ability that can maintain optimum measurement accuracy corresponding to various flow rate regions.

  For example, in a medical device, in the case of a flow sensor built in an artificial dialysis machine, the amount of blood permeated through the dialysis machine varies depending on the physique of patients undergoing dialysis such as infants, children, and adults. The use of different dialysis machines for each patient and the use of dialysis machines with built-in flow sensors in a single dialysis machine impose an excessive burden on facilities such as hospitals.

  Also in the field of semiconductor manufacturing, in order to perform various processing on silicon wafers as appropriate, the wafers are cleaned using a chemical solution such as hydrofluoric acid, sulfuric acid, and ammonia, or ultrapure water. Since the amount of the chemical solution supplied to the wafer varies depending on the process to be performed, a differential pressure type flow sensor capable of measuring the flow rate over a wide range is required. However, the use of a plurality of ranges of flow rate sensors in a single semiconductor manufacturing apparatus not only increases the size of the apparatus but also increases costs.

Accordingly, in one apparatus, there has been a demand for a flow rate measuring apparatus that can be easily adapted to measure different fluid flow rates in a plurality of measurement ranges (measurement ranges) without affecting the cleanliness of the fluid to be measured.
Japanese Patent No. 3220283

  The present invention has been made in view of the above points, and can easily measure different fluid flow rates in a plurality of measurement ranges without affecting the cleanliness of the fluid to be measured while being a single device. Provided is a flow measuring device capable of

That is, the invention of claim 1 is a flow rate measuring device in which a differential pressure type flow rate sensor unit is connected to a main flow channel of a fluid to be measured via a primary side pressure channel and a secondary side pressure channel. The flow rate sensor unit has a first diaphragm and a second diaphragm disposed opposite to each other at both ends of the shaft unit, and a first chamber in contact with the inside of the first diaphragm and a second chamber in contact with the inside of the second diaphragm between the two diaphragms. A load detecting sensor for detecting a back pressure of the diaphragm on a back surface of the first diaphragm, and a load detecting sensor for detecting a back pressure of the diaphragm on the back surface of the first diaphragm. and an arithmetic unit for converting a signal to the flow signal, from the intermediate diaphragm or said first chamber to at least one of said intermediate partition portion Serial pressure loss portion to generate a differential pressure between the first chamber and the second chamber with the passing the fluid to be measured into the second chamber is formed, the primary pressure passage the said main channel The first chamber is connected, the secondary pressure channel is connected to the main channel and the second chamber, and the main channel is connected between the primary pressure channel and the secondary pressure channel. It has at least one movable valve within the movable valve has a poppet valve body with a through-hole is formed which has a diaphragm, wherein the valve chamber of the valve body moves forward and backward said poppet valve body The flow of the fluid flowing out from the outlet is controlled by opening and closing the inlet of the valve chamber, and when the through hole closes the inlet of the valve chamber by the poppet valve body, the flow passage diameter is larger than that of the inlet. The small flow path of the flow A mouth and the valve chamber communicates, according to the flow rate measuring apparatus characterized by causing a differential pressure between the outlet flow path from the valve chamber and the inflow flow path to the valve chamber.

A second aspect of the present invention, when provided with a plurality of the movable valve in one flow path, according to claim 1, any of the on-off valve unit also has the on-off valve unit is arranged in parallel with one flow channel provided The flow rate measuring device according to claim 1.

A flow rate measuring device according to the invention of claim 1 is a flow rate measuring device for connecting a differential pressure type flow rate sensor unit to a main flow channel of a fluid to be measured via a primary side pressure channel and a secondary side pressure channel, The differential pressure type flow rate sensor portion has a first diaphragm and a second diaphragm arranged opposite to each other at both ends of a shaft portion, and a first chamber in contact with the inner side of the first diaphragm and an inner side of the second diaphragm between the two diaphragms. A load detection sensor that includes a second chamber, an intermediate section having an intermediate diaphragm that divides the first chamber and the second chamber, and detects a back pressure of the diaphragm on a back surface of the first diaphragm; and the load detection and an arithmetic unit for converting a signal from the sensor to the flow signal, the intermediate diaphragm or said first channelization at least one of said intermediate partition portion From server to the second chamber pressure loss portion to generate a differential pressure between the first chamber and the second chamber with the passing the fluid to be measured is formed, the primary pressure passage the main channel And the first chamber, the secondary pressure flow path connects the main flow path and the second chamber, and the primary pressure flow path and the secondary pressure flow path are connected to each other. have at least one on-off valve unit within the main flow channel, the on-off valve unit is provided with a poppet valve member having a through hole is formed which has a diaphragm, a valve chamber of the valve body the poppet valve body moves back and forth The flow of the fluid flowing out from the outlet is controlled by opening and closing the inlet of the valve chamber, and when the through hole closes the inlet of the valve chamber by the poppet valve body, Depending on the channel with the smaller channel diameter And communicates with said valve chamber and said inlet, a flow measuring device for generating a differential pressure, to adapt to various applications between the outflow passage side from the inflow flow path between said valve chamber to said valve chamber The fluid pressure loss at the on-off valve part is suppressed and the replacement characteristics are excellent, and the on-off valve part is also used as the pressure loss part to simplify the configuration of the flow rate measuring device. It is possible to easily measure different fluid flow rates in a plurality of measurement ranges without affecting the cleanliness of the fluid to be measured even though it is a single device.

In a second aspect of the present invention, in the first aspect , in the case where a plurality of the on-off valve portions are provided in one flow path, any of the on-off valve portions is arranged in parallel to the single flow path provided with the on-off valve portion. Therefore, one flow path can be configured as a plurality of selectable flow paths.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a schematic view of a fluid supply line in which a flow rate measuring device is arranged, FIG. 2 is a cross-sectional view of a main part of a differential pressure type flow sensor part of FIG. 1 , and FIG. 3 is a main part of an on-off valve part having a poppet valve body. sectional view, cross sectional view of a differential pressure type flow sensor of the flow rate measuring apparatus according to the first embodiment of FIG. 4 is the invention, FIG 5 is other peripheral intermediate section of the differential pressure type flow rate sensor of the first embodiment It is principal part sectional drawing showing the example of.

Shown to the flow measuring device 10A in FIG. 1, the differential pressure type flow rate sensor part 20A via the primary pressure passage 12 and the secondary pressure passage 13 to the main channel 11 of the fluid to be measured is connected. In the figure, reference numeral 16 denotes a supply unit for supplying the fluid to be measured to the main flow path 11, and 17 denotes a use part of the supplied fluid to be measured. Here, the primary side is the upstream side (supply side 16 side) of the supply line through which the fluid to be measured flows, and the secondary side is the downstream side (use unit 17 side).

  As shown in FIG. 2, in the differential pressure type flow sensor unit 20 </ b> A, the first diaphragm 30 and the second diaphragm 35 are disposed opposite to each other at both ends of the shaft unit 36. Between the both diaphragms 30 and 35, a first chamber 23 facing the inside of the first diaphragm 30, a second chamber 24 facing the inside of the second diaphragm 35, a first chamber 23 and a second chamber 24 are provided. An intermediate section 22 having an intermediate diaphragm 26 for partitioning is provided. A back surface of the first diaphragm 30 includes a load detection sensor 40 that detects the back pressure of the diaphragm 30 and a calculation unit C that converts a signal from the load detection sensor 40 into a fluid signal.

  In the differential pressure type flow sensor unit 20A, the load detection sensor 40 is a known load cell that detects a compressive strain with a strain gauge and extracts it as a voltage signal. As the calculation unit C, known calculation means such as PLC is used. In FIG. 2, reference numeral 21 denotes a body body of the differential pressure type flow rate sensor unit 20 </ b> A, 27 denotes an inflow portion of a fluid to be measured formed in the first chamber 23, and 28 denotes a fluid to be measured formed in the second chamber 24. An outflow part 41 is a lead wire for connecting the load detection sensor 40 and the calculation part C.

  In the differential pressure type flow rate sensor unit 20A, the flow rate is measured based on the differential pressure generated according to the flow path area of the pressure loss unit 50 described later. Therefore, in the calculation unit C of the differential pressure type flow rate sensor unit 20A, a differential pressure value corresponding to the flow path area of the pressure loss unit 50, a flow rate value determined based on the differential pressure, or a polygonal line approximation thereof is previously stored. An optimum flow rate measurement range is set for the stored flow rate value in consideration of measurement errors and the like. As will be described later, when a plurality of types of pressure loss portions 50 are arranged in the flow channel to be measured, the differential pressure value and the flow rate value corresponding to the flow channel area of each pressure loss portion 50 respectively. Alternatively, those broken line approximations are stored, and a plurality of types of flow rate measurement ranges that are optimum for each flow rate value are set.

  In this flow measuring device 10 </ b> A, the primary side pressure channel 12 connects the main channel 11 and the first chamber 23, and the secondary side pressure channel 13 connects the main channel 11 and the second chamber 24. Between the first chamber 23 and the second chamber 24, a pressure loss part 50 that generates a differential pressure is arranged, and the main flow path between the primary pressure flow path 12 and the secondary pressure flow path 13 is connected. 11 is provided with at least one on-off valve portion 60.

  At least one pressure loss unit 50 is provided in a flow path that connects the first chamber 23 and the second chamber 24 of the differential pressure type flow rate sensor unit 20A. Then, the differential pressure type flow rate sensor unit 20A is configured to measure the flow rate of the fluid to be measured based on the differential pressure generated by the pressure loss unit 50. The pressure loss portion 50 may have any configuration as long as the flow path area can be reduced to generate a differential pressure. For example, the flow path has a known Venturi tube structure. An appropriate configuration, such as providing an orifice portion, can be employed.

The on-off valve unit 60 is configured to freely open and close an appropriate flow path through which the fluid to be measured flows. The on-off valve unit 60 may have any configuration as long as it can open and close an appropriate flow path. For example, the on-off valve part 70 provided with the poppet valve body 75 shown in FIG. 3 etc. is used.

  The on-off valve portion 70 shown in FIG. 3 is a fluid that flows out of the outlet 74 by controlling the opening and closing of the inlet 73 of the valve chamber 72 by the poppet valve body 75 having a diaphragm 75A moving forward and backward in the valve chamber 72 of the valve body 71. Control the distribution of In this figure, reference numeral 76 is a fluid inflow channel, 77 is an outflow channel, 80 is an operating mechanism (cylinder device) of the poppet valve body 75, 81 is its cylinder chamber, 82 is a cylinder chamber 81 and a valve chamber 72. A partition block for partitioning, 83 is a piston member connected to the poppet valve body 75, 84 and 85 are inflow / outflow portions of the working fluid for moving the piston member 83 forward and backward, 86 is an air vent portion, 87 is a mounting member for the poppet valve body 75, Reference numeral 88 denotes an elastic member that urges the poppet valve body 75 in the forward direction.

  In this on-off valve portion 70, as shown in FIG. 3, the outlet 74 is formed on the side of the valve chamber 72 and the outlet passage 77 is connected, so that the valve passes from the inlet passage 76 through the inlet 73. The fluid flowing into the chamber 72 flows from the valve chamber 72 through the outflow port 74 to the outflow channel 77 in the linear direction. Therefore, the pressure loss of the fluid is reduced and the replacement characteristics are excellent.

  Further, as shown in FIG. 3, a through-hole 78 is formed in the poppet valve body 75. The through-hole 78 allows the inlet 73 and the valve chamber 72 to communicate with each other through a channel having a channel diameter smaller than that of the inlet 73 when the poppet valve body 75 is advanced to close the inlet 73. Therefore, the through-hole 78 acts as an orifice part that generates a differential pressure between the inflow channel 76 side and the outflow channel 77 side. Thereby, it becomes possible to make the on-off valve part 70 share the pressure loss part 50, and simplification of the structure of the said flow measurement apparatus 10A can be achieved. When the through-hole 78 is formed in the poppet valve body 75, the pressure loss part 50 such as an orifice part may not be arranged in the flow path in which the on-off valve part 70 is arranged.

In flow measuring apparatus 10A, as shown in FIGS. 1 and 2, a plurality off valve 60 (first opening and closing valve 61, second on-off valve 62) of (two in this example) relative to the main channel 11 Are arranged in parallel. That is, the main flow path 11 has a first branch flow path 15a and a second branch flow path 15b, and the first on-off valve section 61 and the second on-off valve section 62 are provided in each of the branch flow paths 15a and 15b. Configured to be deployed. Incidentally, the on-off valve unit 60 of this, inlet passages (76, 96) corresponds to the branch paths 15a, 15b supply 16 side flow path of the outflow channel (77,97) is the branch paths It corresponds to the use part 17 side flow path of 15a, 15b.

  In the flow rate measuring device 10A, when the first on-off valve unit 61 is in the open state and the second on-off valve unit 62 is in the closed state, the first chamber 23 and the second chamber 24 of the differential pressure type flow rate sensor unit 20A The primary side pressure channel 12 communicates with the secondary side pressure channel 13 via the first branch channel 15a.

  When the first on-off valve portion 61 is closed and the second on-off valve portion 62 is in the open state, the first chamber 23 and the second chamber 24 of the differential pressure type flow rate sensor portion 20A are connected to the primary side pressure channel 12. To the secondary branch pressure channel 13 through the second branch channel 15b.

  On the other hand, when each of the on-off valve parts 61 and 62 is in an open state, the first chamber 23 and the second chamber 24 of the differential pressure type flow rate sensor part 20A are connected from the primary pressure flow path 12 to the first branch flow path 15a. In addition, the secondary side pressure channel 13 communicates with the secondary side pressure channel 13 and the secondary side pressure channel 13 communicates with the secondary side pressure channel 13 through the second branch channel 15b.

  As described above, the plurality of on-off valve portions 60 (61, 62) are arranged in parallel to the main flow path 11, thereby allowing the first chamber 23 and the second chamber 24 of the differential pressure type flow rate sensor portion 20A to communicate with each other. It is possible to selectively configure the types of flow paths.

Further, in this flow measuring device 10A, as described above, there are a plurality of types of flow paths for communicating the first chamber 23 and the second chamber 24 (in this example, the first branch flow path 15a and the second branch flow path 15b). When configured, at least one or more pressure loss portions 50 are arranged for any flow path (the first branch flow path 15a and the second branch flow path 15b) that communicates the first chamber 23 and the second chamber 24. (In this example, the first pressure loss portion 51 is configured with respect to the first branch flow path 15a, and the second pressure loss portion 52 is configured with respect to the second branch flow path 15b). In that case, each pressure loss part 51 and 52 is suitably set so that the differential pressure | voltage corresponding to the flow volume of each flow path 15a, 15b can be generated, respectively.

  Here, the operation of the flow measuring device 10A will be described. In this flow measurement device 10A, the calculation unit C of the differential pressure type flow sensor unit 20A has a polyline approximation of the differential pressure value of the first pressure loss unit 51 arranged in the first branch flow path 15a and the flow rate value based on the differential pressure value. The differential pressure value of the second pressure loss portion 52 arranged in the second branch flow path 15b and the broken line approximation of the flow rate value based on the differential pressure value, the differential pressure value of the first pressure loss portion 51 and the second pressure loss portion 52, and The broken line approximation of the flow rate value based on each is memorize | stored. And the flow measurement range corresponding to each flow value is set up, respectively. Temporarily, the flow rate measurable by the first pressure loss unit 51 is 10 to 50 mL / min, the flow rate measurable by the second pressure loss unit 52 is 50 to 150 mL / min, the first pressure loss unit 51 and the second pressure loss unit. The flow rate measurable by 52 is explained as 10 to 200 mL / min.

  First, when a fluid to be measured of 50 mL / min is circulated, the first on-off valve unit 61 is opened and the second on-off valve unit 62 is closed, and the first chamber 23 and the second chamber of the differential pressure type flow rate sensor unit 20A. 24, the flow path is selected so that the fluid to be measured flows only through the first branch flow path 15a. At that time, the calculation unit C of the differential pressure type flow rate sensor unit 20A selects the value of the differential pressure based on the first pressure loss unit 51 and the broken line approximation of the flow rate value, and sets the corresponding flow rate measurement range.

  Further, when the fluid to be measured of 150 mL / min is circulated, the first on-off valve portion 61 is closed and the second on-off valve portion 62 is opened, and the first chamber 23 and the second chamber of the differential pressure type flow rate sensor portion 20A. In the main channel between the channels 24 and 24, the channel is selected so that the fluid to be measured flows only through the second branch channel 15b. At that time, the calculation unit C of the differential pressure type flow rate sensor unit 20A selects the value of the differential pressure based on the second pressure loss unit 52 and the broken line approximation of the flow rate value, and sets the corresponding flow rate measurement range.

  Further, when the fluid to be measured of 200 mL / min is circulated, both the on-off valve portions 61 and 62 are opened, and in the main flow path between the first chamber 23 and the second chamber 24 of the differential pressure type flow sensor unit 20A. The flow path is selected so that the fluid to be measured flows through both the first branch flow path 15a and the second branch flow path 15b. At that time, in the calculation unit C of the differential pressure type flow rate sensor unit 20A, a polygonal line approximation of the differential pressure value and the flow rate value based on the first pressure loss unit 51 and the second pressure loss unit 52 is selected, and the corresponding flow rate measurement range is selected. Is set.

Therefore , in the flow measurement device 10A, even when the fluid to be measured having different flow rates is switched and circulated, the measurement range corresponding to each target flow rate can be easily set even though it is a single device. Can do.

The flow rate measuring device 10B according to the first embodiment of the present invention shown in FIG. 4 includes a differential pressure type flow rate sensor unit via a primary side pressure channel 12 and a secondary side pressure channel 13 in the main channel 11 of the fluid to be measured. 20B is connected. In the following examples , the same reference numerals as those of the flow measurement device 10A represent the same configuration, and the description thereof is omitted.

  In the flow rate measuring device 10B, in the differential pressure type flow rate sensor unit 20B, a through channel 29 is formed in the intermediate diaphragm 26 to allow the fluid to be measured to pass from the first chamber 23 to the second chamber 24. The through channel 29 acts as a pressure loss unit 50 that generates a differential pressure between the first chamber 23 and the second chamber 24.

  In the flow rate measuring device 10B, when the first on-off valve unit 61 is in the open state and the second on-off valve unit 62 is in the closed state, the first chamber 23 and the second chamber 24 of the differential pressure type flow rate sensor unit 20B Is communicated from the primary side pressure channel 12 via the first branch channel 15 a and through the secondary side pressure channel 13 and through the through channel 29.

  When the first on-off valve portion 61 is closed and the second on-off valve portion 62 is in the open state, the first chamber 23 and the second chamber 24 of the differential pressure type flow rate sensor portion 20B are connected to the primary side pressure channel 12. To the secondary pressure flow channel 13 through the second branch flow channel 15 b and the through flow channel 29.

  When each of the on-off valve parts 61 and 62 is in an open state, the first chamber 23 and the second chamber 24 of the differential pressure type flow rate sensor part 20B pass from the primary pressure flow path 12 through the branch flow paths 15a and 15b. The secondary side pressure channel 13 communicates with each other and the through channel 29 communicates.

  On the other hand, when both of the on-off valve portions 61 and 62 are in the closed state, the first chamber 23 and the second chamber 24 of the differential pressure type flow rate sensor portion 20A are communicated only through the through passage 29. That is, the fluid to be measured is circulated from the primary side pressure channel 12 to the secondary side pressure channel 13 through the through channel 29.

  As described above, the intermediate diaphragm 26 of the differential pressure type flow rate sensor unit 20B is provided with the pressure loss unit 50 (through channel 29) through which the fluid to be measured can be passed from the first chamber 23 to the second chamber 24. By providing at least one on-off valve part 60 in the main flow path 11 while the secondary pressure flow path 12 and the secondary pressure flow path 13 are connected, the first chamber 23 and the second pressure sensor 20B of the differential pressure type flow rate sensor part 20B are provided. A plurality of types of flow paths that communicate with the chamber 24 can be selectively configured.

  Further, in the flow rate measuring device 10B, as described above, there are a plurality of types of flow paths for communicating the first chamber 23 and the second chamber 24 (in the embodiment, the branched flow paths 15a and 15b and the through flow path 29). In this case, at least one or more pressure loss portions 50 are disposed in any flow path (each branch flow path 15a, 15b, through flow path 29) that communicates the first chamber 23 and the second chamber 24 ( In this example, the first pressure loss section 51 corresponds to the first branch flow path 15a, the second pressure loss section 52 and the through flow path 29 correspond to the third pressure loss section 53 to the second branch flow path 15b) It is configured as follows. In that case, each pressure loss part 51,52,53 is suitably set so that the differential pressure | voltage corresponding to the flow volume of each flow path 15a, 15b, 29A can each be generated.

  Here, the operation of the flow measurement device 10B will be described. In the flow rate measuring device 10B, the calculation unit C of the differential pressure type flow rate sensor unit 20B includes a value of the differential pressure of the third pressure loss unit 53, which is the through passage 29, and a polygonal line approximation of the flow rate value based on the differential pressure value. A value of the differential pressure between the first pressure loss part 51 and the third pressure loss part 53 arranged in the passage 15a and a broken line approximation of the flow rate value based on the value, a second pressure loss part 52 arranged in the second branch flow path 15b, and The differential pressure value of the third pressure loss part 53 and the polygonal line approximation of the flow rate value based on it, the differential pressure value between the first pressure loss part 51, the second pressure loss part 52 and the third pressure loss part 53 and the flow rate based thereon A broken line approximation of values is stored. Temporarily, the flow rate measurable by the 3rd pressure loss part 53 is 1-10 mL / min, The flow rate measurable by the 1st pressure loss part 51 and the 3rd pressure loss part 53 is 1-60 mL / min, 2nd pressure loss part The flow rate measurable by 52 and the third pressure loss part 53 is 1 to 160 mL / min, and the flow rate measurable by the first pressure loss part 51, the second pressure loss part 52 and the third pressure loss part 53 is 1 to 210 mL / min. This will be described as min.

  First, when the fluid to be measured of 60 mL / min is circulated, the first on-off valve portion 61 is opened and the second on-off valve portion 62 is closed, and the fluid to be measured is the first chamber 23 of the differential pressure type flow sensor unit 20B. The flow path is selected so as to circulate via the first branch flow path 15 a and the through flow path 29 between the first chamber 24 and the second chamber 24. At that time, in the calculation unit C of the differential pressure type flow rate sensor unit 20B, a polygonal line approximation of the differential pressure value and the flow rate value based on the first pressure loss unit 51 and the third pressure loss unit 53 is selected, and the corresponding flow rate measurement range is selected. Is set.

  When the fluid to be measured of 160 mL / min is circulated, the first on-off valve unit 61 is closed and the second on-off valve unit 62 is opened, and the fluid to be measured is connected to the first chamber 23 of the differential pressure type flow rate sensor unit 20B and the first chamber 23. The flow path is selected so as to circulate via the second branch flow path 15 b and the through flow path 29 between the two chambers 24. At that time, the calculation unit C of the differential pressure type flow rate sensor unit 20B selects the line pressure approximation of the differential pressure value and the flow rate value based on the second pressure loss unit 52 and the third pressure loss unit 53, and the corresponding flow rate measurement range. Is set.

  When the fluid to be measured of 210 mL / min is circulated, both the first and second on-off valve portions 61 and 62 are opened, and the fluid to be measured is in the first chamber 23 and the second chamber 24 of the differential pressure type flow rate sensor portion 20B. The flow paths are selected so as to circulate through both the first branch flow path 15a and the second branch flow path 15b and the through flow path 29. At that time, the calculation unit C of the differential pressure type flow rate sensor unit 20B selects the polyline approximation of the differential pressure value and the flow rate value based on the first pressure loss unit 51, the second pressure loss unit 52, and the third pressure loss unit 53. Accordingly, the corresponding flow rate measurement range is set.

  When circulating a fluid to be measured of 25 mL / min, the first and second on-off valve portions 61 and 62 are closed, and the flow path is selected so that the fluid to be measured flows only through the through flow path 29. The At that time, the calculation unit C of the differential pressure type flow rate sensor unit 20B selects the value of the differential pressure based on the third pressure loss unit 53 and the broken line approximation of the flow rate value, and sets the corresponding flow rate measurement range.

  Therefore, in the flow rate measuring device 10B of the present invention, even if the fluids to be measured having different flow rates are switched and circulated, a measurement range corresponding to each target flow rate can be easily obtained even though it is a single device. Can be set. In the differential pressure type flow rate sensor unit 20B, the pressure loss unit 50 that causes the fluid to be measured to pass from the first chamber 23 to the second chamber 24 and generates a differential pressure between the first chamber 23 and the second chamber 24. Even when the through flow passage 29A is formed in the intermediate partition 22 as shown in FIG. 6, the same effect can be obtained.

In the flow measuring device 10A, 10 B, each passage 11, 12, 13 and, differential pressure type flow sensor unit 20A, 20B, the pressure loss unit 50, the measured fluid contacts the movable valve 60 (70) or the like The member is made of a fluororesin excellent in corrosion resistance and chemical resistance. The fluororesin that is the material of the member is PTFE (polytetrafluoroethylene), PFA (perfluoroalkoxyalkane), FEP (perfluoroethylene propene copolymer), PVDF (polyvinylidene fluoride), or the like. These fluororesins are selected in consideration of the properties of the flowing fluid, ease of processing, and the like. Thereby, it is suppressed that the cleanliness is influenced at the time of measurement of the fluid to be measured.

Above illustrated as described, the flow measuring device 10B of the present invention, without affecting yet one device to cleanliness of the fluid to be measured, measuring the fluid flow rate of different conveniently plurality of measurement range Can do. Therefore, for example, in a medical device, if the flow measuring device is built in an artificial dialysis machine or the like, the patient undergoing dialysis may have different blood volume permeating through the dialysis machine due to differences in physique between infants, children, adults, etc. However, it is not necessary to use a different dialysis machine for each patient, and the work efficiency and equipment burden can be greatly improved.

In particular, in the flow measuring device, by adopting the structure that (a through channel formed in the diaphragm or the intermediate partition portion between the medium) connecting the first chamber and the second chamber, adapted to a variety of applications, such as the Therefore, it is possible to design the flow rate measuring device flexibly and perform more accurate flow rate measurement.

  Also in the semiconductor manufacturing field, it is not necessary to use different flow rate sensors with different measurement ranges for each required process, and the equipment burden can be reduced.

  The flow rate measuring device of the present invention is not limited to the above-described embodiment, and can be implemented by appropriately changing a part of the configuration without departing from the spirit of the invention. For example, the opening / closing operation or the like of each opening / closing valve unit may be configured to be controllable by the calculation unit of the differential pressure type flow rate sensor unit. If comprised in this way, selection switching of each flow path can be performed effectively and efficiently.

  In the embodiment, the main flow path is provided with two branch flow paths and the on-off valve parts are arranged in parallel. However, the number of the on-off valve parts to be arranged in parallel is not limited to this, and as necessary. Can be increased or decreased.

Flow rate measuring device is a schematic view of a supply line arrangement fluid. It is a fragmentary cross-sectional view of a differential pressure type flow rate sensor of FIG. It is principal part sectional drawing of the on-off valve part provided with the poppet valve body. It is principal part sectional drawing of the differential pressure type flow sensor part of the flow measuring apparatus which concerns on 1st Example of this invention . It is principal part sectional drawing showing the other example of the intermediate partition part periphery of the differential pressure type flow sensor part of 1st Example. It is a schematic diagram.

10A, 10 B flow measuring device 11 main flow path 12 primary pressure passage 13 secondary pressure passage 16 supplying unit 17 using unit 20A, 20 B difference pressure flow sensor unit 50 the pressure loss unit 60 on-off valve unit

Claims (2)

A flow rate measuring device for connecting a differential pressure type flow rate sensor unit to a main flow channel of a fluid to be measured via a primary pressure channel and a secondary pressure channel,
The differential pressure type flow rate sensor portion has a first diaphragm and a second diaphragm arranged opposite to each other at both ends of a shaft portion, and a first chamber in contact with the inner side of the first diaphragm and an inner side of the second diaphragm between the two diaphragms. A load detection sensor that includes a second chamber, an intermediate section having an intermediate diaphragm that divides the first chamber and the second chamber, and detects a back pressure of the diaphragm on a back surface of the first diaphragm; and the load detection A calculation unit that converts a signal from the sensor into a flow signal, and allows the fluid to be measured to pass from the first chamber to the second chamber through at least one of the intermediate diaphragm and the intermediate partition unit, and the first chamber And a pressure loss portion that creates a differential pressure between the second chamber and the second chamber,
The primary pressure flow path connects the main flow path and the first chamber, the secondary pressure flow path connects the main flow path and the second chamber,
Possess the at least one movable valve in the main flow path between said primary pressure passage and the secondary pressure passage is connected,
The on-off valve portion includes a poppet valve body having a diaphragm and having a through-hole, and the poppet valve body advances and retreats in the valve chamber of the valve body to control opening and closing of the inlet of the valve chamber. And controlling the flow of the fluid flowing out of the inlet and the valve chamber by means of a channel having a smaller channel diameter than the inlet when the through hole closes the inlet of the valve chamber by the poppet valve body. To generate a differential pressure between the inflow channel side to the valve chamber and the outflow channel side from the valve chamber . 2. The flow rate measuring device according to claim 1 , wherein when a plurality of the on-off valve portions are provided in one flow path, any of the on-off valve portions is arranged in parallel to the one flow path provided with the on-off valve portion.

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