JPH0590326U - Flow rate measuring device - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a flow rate measuring device which does not require difficulty in manufacturing and can reliably prevent extraction of a component into a fluid to be measured. A light emitting portion and a light receiving portion of an optical sensor are arranged at positions in the housing so as to sandwich the impeller from the axial direction, and the rotational speed of the impeller is detected by the optical sensor. Further, the housing and the impeller are made of a material having chemical resistance, and the portion supporting the impeller is made of a jewel having excellent wear resistance and chemical resistance.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an improvement in a flow rate measuring device for measuring the flow rate of pure water, a chemical solution or the like used in the manufacturing process of a semiconductor, liquid crystal, medical, food, etc. manufacturing factory.

[0002]

[Prior Art]

 The conventional flow rate measuring device has, for example, a configuration as shown in FIGS. 6 and 7. First, there is a housing 101, and an impeller 103 is rotatably arranged in the housing 101. The impeller 103 is composed of a shaft 105 axially supported by the housing 103, a boss portion 107 fixed to the shaft 105, and a plurality of blades 109 extending radially from the boss portion 107. ing. A magnet 111 is embedded on the upper surface side of each blade 109 in the drawing. On the other hand, a magnetic operation type proximity switch 113 is installed on one side of the upper part of the housing 103 in the figure. Reference numerals 115 and 117 in FIG. 7 are bearings, and these bearings 115 and 117 are made of resin, metal or carbon.

On the other hand, the measurement target fluid circulates in the pipe 116 as shown in FIG. 6, and the impeller 103 rotates due to the circulation of the measurement target fluid. The rotation of the impeller 103 causes the magnet 111 attached to each blade 109 to pass below the magnetically actuated proximity switch 113. By detecting the number of N / S pulses at that time by the magnetic operation type proximity switch 113, the flow velocity and thus the flow rate of the fluid to be measured is measured.

[0004]

[Problems to be solved by the device]

 The above-mentioned conventional configuration has the following problems. First, in semiconductor manufacturing plants, etc., the flow rate of various chemicals such as strong acidity and strong alkalinity may be measured, and at that time, the liquid contact part of the flow rate measurement device causes a chemical reaction by the chemicals and The ingredients may be extracted into the drug. In that case, the purity of the drug will be impaired. Therefore, as a member that constitutes the liquid contact portion, a limited material (for example, fluororesin) that does not cause such a chemical reaction is used. In the case of the type using the magnet 111 described above, when the magnet 111 is exposed and used, the above-mentioned chemical reaction is concerned, so in a state where it is not brought into contact with a fluid. It was necessary to attach it to the blade 109, which made assembly difficult. Further, even if the magnet 111 is embedded so as not to come into contact with the fluid, the fluid may permeate to reach the magnet 111 during long-term use, causing a chemical reaction there and extracting components.

Further, as the parts of the impeller 103, those made of a material having excellent chemical resistance are used as described above. However, for example, abrasion due to sliding friction between the shaft 105 and the bearings 115 and 117 is used. There is also a problem that powder may be generated, and this wear powder is mixed in the fluid.

The present invention has been made on the basis of such a point. The object of the present invention is to make it difficult to assemble and to reliably prevent the extraction of components into the fluid to be measured. At the same time, it is another object of the present invention to provide a flow rate measuring device capable of maintaining the purity of the fluid to be measured by suppressing the generation of abrasion powder due to sliding friction.

[0007]

[Means for Solving the Problems]

 In order to achieve the above object, in the flow rate measuring device according to the present invention, the fluid to be measured circulates in the housing, and at that time, the impeller rotatably arranged in the housing rotates to detect the rotational speed of the impeller In the flow rate measuring device for measuring the flow rate, the light emitting part and the light receiving part of the optical sensor are arranged at positions in the housing so as to sandwich the impeller from the axial direction. It is characterized in that the number of rotations is detected.

In addition, a fluid to be measured circulates in the housing, at which time an impeller rotatably disposed in the housing rotates, and a flow rate measuring device that measures the flow rate by detecting the number of revolutions of the impeller In the above, at least the housing and the impregnated part of the impeller are made of a material having chemical resistance, and the whole or part of the structure that pivotally supports the impeller is made of a gemstone excellent in abrasion resistance and chemical resistance. It is characterized by being configured.

[0009]

[Action]

 First, the light emitting part and the light receiving part of the optical sensor are arranged at positions in the housing so as to sandwich the impeller from the axial direction, and the optical sensor detects the rotational speed of the impeller. As described above, there is no need to perform a difficult work such as embedding a magnet in the blade, and there is no possibility that the fluid permeates into that portion and components are extracted into the fluid.

In addition, at least the housing and the impregnated portion of the impeller are made of a material having chemical resistance, and all or part of the structure that axially supports the impeller has excellent wear resistance and chemical resistance. When it is made of gemstones, it is possible to prevent the components from being extracted into the fluid due to the reaction with the fluid, and also to suppress the generation of abrasion powder due to sliding resistance and to extract the abrasion powder into the fluid. Can be prevented.

[0011]

【Example】

 An embodiment of the present invention will be described below with reference to FIGS. The flow rate measuring device according to the present embodiment has a configuration as shown in FIGS. First, there is a housing 1, and an impeller 3 is rotatably accommodated in the housing 1. The impeller 3 is composed of a boss portion 5 and a plurality of blades 7 extending radially from the boss portion 5 and the like. A bearing 9 is attached to the upper surface side of the boss portion 5 in the drawing, and a shaft 11 is attached to the lower surface side of the boss portion 5 in the drawing. On the other hand, a shaft 13 and a bearing 15 are attached to the housing 1 side. The shafts 11, 13 and the bearings 9, 15 are all made of sapphire, which is a gemstone having excellent wear resistance and chemical resistance. As a result, generation of abrasion powder due to sliding friction is suppressed. In addition to sapphire, it is possible to use jewels such as rubies and diamonds.

An optoelectronic sensor 17 as an optical sensor is attached to the housing 1. The optoelectronic sensor 17 is composed of a light projector 19 as a light emitting unit attached to the upper portion of the housing 1 in the drawing, and a light receiving unit 21 as a light receiving portion attached to the lower portion of the housing 1 in the drawing. The light emitted from the light projector 19 is received by the light receiver 21. At that time, when the impeller 3 rotates due to the flow of the fluid, each blade 7 passes between the light projector 19 and the light receiver 21, whereby the light is blocked. By detecting the output pulse resulting from this, the flow velocity of the fluid and thus the flow rate are measured. That is, as shown in FIG. 3, the digital tachometer 25 is used to display the instantaneous flow rate, and as shown in FIG. 4, the integrator 27 is used to display the integrated flow rate. As described above, the F / V converter 29 is used for analog output.

As described above, according to this embodiment, the following actions and effects can be achieved. First, unlike the conventional magnet type, it is not necessary to embed the magnets in the blades 7, so that the assembly is easy and the components may be extracted by the chemical reaction due to the contact with the fluid. lost. Therefore, the purity of the fluid to be measured can be maintained for a long time. Further, since the shafts 11 and 13 for axially supporting the impeller 3 and the bearings 9 and 15 are made of sapphire excellent in wear resistance and chemical resistance, generation of abrasion powder due to sliding friction is prevented. Can be suppressed. Of course, the other liquid contact parts are made of a chemical resistant material so that they do not cause a chemical reaction when they come into contact with the fluid.

The present invention is not limited to the above embodiment. First, the optical sensor is not limited to the phototube sensor in the above-described embodiment, and may be another optical sensor. Further, in the above-described embodiment, the shaft and the bearing are respectively provided on the boss portion 5, but both may be the shaft or both may be the bearings. Further, although the shaft and the bearing are all made of jewels in the above-mentioned one embodiment, it is also conceivable that only the contact portion is made of jewel.

[0015]

[Effect of the device]

 As described above in detail, according to the flow rate measuring device of the present invention, the assembly is simplified, the components of the flow rate measuring device are prevented from being extracted due to the reaction with the fluid, and the shaft of the impeller is prevented. It is possible to suppress the generation of abrasion powder due to the sliding friction of the bearing, and to prevent impairing the purity of the fluid.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of the present invention with a part of a flow rate measuring device cut away.

FIG. 2 is a cross-sectional view of a flow rate measuring device showing an embodiment of the present invention.

FIG. 3 is a diagram showing an embodiment of the present invention, showing a state in which a digital tachometer is connected to a flow rate measuring device.

FIG. 4 is a view showing an embodiment of the present invention, showing a state in which an integrator is connected to the flow rate measuring device.

FIG. 5 is a view showing an embodiment of the present invention in which a converter is connected to a flow rate measuring device.

FIG. 6 is a plan view showing a conventional example with a part of the flow rate measuring device cut away.

FIG. 7 is a cross-sectional view of a flow rate measuring device showing a conventional example.

[Simple explanation of symbols]

 1 Housing 3 Impeller 5 Boss 7 Blade 9 Bearing 11 Shaft 13 Shaft 15 Bearing 17 Photoelectric Sensor (Optical Sensor) 19 Emitter (Light Emitting Unit) 21 Light Receiver (Light Receiving Unit)

Claims (2)

[Scope of utility model registration request] 1. A fluid to be measured flows in the housing,
At that time, an impeller rotatably arranged in the housing rotates, and in a flow rate measuring device that measures the flow rate by detecting the number of rotations of the impeller, the impeller is sandwiched in the housing from the axial direction. A flow rate measuring device characterized in that a light emitting part and a light receiving part of an optical sensor are arranged at respective positions, and the rotational speed of the impeller is detected by the optical sensor. 2. The fluid to be measured circulates in the housing,
At that time, an impeller rotatably arranged in the housing rotates, and in a flow rate measuring device for measuring a flow rate by detecting the number of rotations of the impeller, at least the liquid contact portion of the housing and the impeller is chemically resistant. A flow rate measuring device comprising a jewel that has excellent wear resistance and chemical resistance.