JPH0828720A - Ball valve for gas conduit - Google Patents

Abstract

PURPOSE:To miniaturize a pit for receiving a ball valve capable of shutting off gas as a shut-off valve in a gas supply system and measuring a flow of the gas simultaneously, and reduce the installation cost. CONSTITUTION:A ball valve consists of a spherical valve element 22 having a through hole 25 having the same diameter as the inner diameter of a conduit in which the ball valve intervenes and a valve body 20 for rotatably supporting and receiving the valve element 22 around the vertical axis. The through hole 25 of the valve element 22 in opening the valve is located coaxially with a gas conduit and in closing the valve, located at a right angle to the conduit. This ball valve is provided with a flow detecting body 34 suspended in the through hole 25 of the valve element 22 and a flow calculator 42 for calculating the gas flow on the basis of a signal from the flow detecting body 34 so that a single valve is constituted to shut off the gas and measure the flow.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ball valve used as a gas shutoff valve or a flow rate adjusting valve on a conduit of a gas supply conduit, and more particularly to a flow rate detecting sensor in a spherical valve body having a through hole. The present invention relates to a ball valve which has a built-in valve and can simultaneously measure the gas flow rate in addition to the original function of the valve.

[0002]

2. Description of the Related Art As shown in FIG. 1, a gas supply system is
The gas (pressure = 10 kg / cm ² or more) produced in the factory 1 is sent to the governor station 3 through the high pressure conduit 2,
Gas decompressed at governor station 3 (pressure = 10k
(less than g / cm ^{2 to 1} kg / cm ² or more) is delivered to the district governor 5 of each consumption area by the medium pressure conduit 4, and the gas (less than 1 kg / cm ² ) decompressed in the district governor 5 is distributed by the low pressure conduit 6. The method of supplying to the consumer 7 is adopted.

In this gas supply system, as a measure against disasters such as an earthquake, the gas supply from the factory 1 is urgently urged to the high-pressure conduit 2 so that the gas supply can be shut off based on a command from the central monitoring center 8. A shutoff valve 10 is provided, and a regional block valve 11 (shutoff valve) is provided in the medium-pressure conduit 4 leading to the district governor 5 in each consumption area.

At the installation position of the regional block valve 11 (shutoff valve), the gas flow rate is measured at the same time as shutting off the gas so that it can be controlled whether or not the supply gas is stably supplied to each of the downstream consumption areas. I can do it. Therefore, normally, at the installation position of the regional block valve 11, a hot tapping 13 is provided in the installation pit 12 as shown in FIG. And a gas pressure gauge 14 are provided.

The hot tapping 13 has a sensor 15 for detecting a flow rate in the conduit of the intermediate pressure conduit 2 as seen in a known gas flow meter (see, for example, Japanese Patent Laid-Open No. 4-2922).
And the static pressure and dynamic pressure of the gas obtained from the sensor 15 are guided to the flow rate calculator 18 on the ground by the pressure guiding pipes 16 and 17 so that the gas flow rate can be calculated from the pressure difference between the two. It has a flow rate measuring means. During this flow rate measurement, water vapor or tar in the gas adheres to the flow rate detection sensor 15 to cause an error, so that the hot tapping 13 described above is performed so that maintenance work such as cleaning and replacement can be performed.
An opening / closing valve 19 and a space portion 20 for maintenance and inspection are formed above the valve position in the gas extraction passage, and the flow rate detecting sensor 15 is pulled up inside the space portion 20 to perform maintenance work there. I am trying. Therefore, the hot tapping 13 has a configuration in which it is relatively long in the vertical direction.

[0006]

When detecting the flow rate of gas, the flow rate detection sensor 15 must be installed in a straight pipe portion having the same length and a required length in order to ensure its accuracy. Therefore, the above regional block valve 11
When the hot tapping 13 and the pressure gauge 14 for detecting the flow rate are provided in the pit 12 for installing the (shutoff valve), the pit 17 must be large in order to secure the span of the straight pipe portion. And the construction cost for constructing the pit becomes expensive.

In particular, since the regional block valves 11 are separately provided in front of the district governor 5 which is divided from the governor station 3 into each consumption area, the number of the regional block valves 11 to be installed is several thousand as a whole (about 5000). As a result, the construction cost required to install the regional block valve 11 is enormous.

In view of the above problems, the present invention eliminates the need for a conventional hot tapping or pressure gauge when installing a regional block valve or the like as a shutoff valve on the conduit of the gas supply conduit. It is an object of the present invention to provide a ball valve that can perform gas shutoff and gas flow measurement simultaneously with a single valve.

[0009]

In order to achieve the above object, a valve according to the present invention comprises a spherical valve body having a through hole having the same diameter as the inner diameter of a conduit, and the valve body being rotatable about a vertical axis. A ball valve that is composed of a valve body that is supported and housed in the valve body, and has a through hole of the valve body positioned coaxially with the gas conduit to allow the gas to flow therethrough, and a through hole positioned at a right angle to the conduit to shut off or adjust the flow rate of the gas. The ball valve is provided with a flow rate detection sensor for the gas passing through the through hole of the valve body, and the gas flow rate is measured based on the signal obtained from the flow rate detection sensor. The present invention is characterized in that it is provided with a flow rate calculating means, and in addition to the original function of the valve, the flow rate of gas can be simultaneously measured by a single ball valve.

[0010]

According to the ball valve having such a structure, since the valve body is a spherical body having a through hole having the same diameter as the inner diameter of the conduit, a span of the straight pipe portion for providing the flow rate detection sensor is newly secured. Moreover, since the gas shutoff and the flow rate measurement can be achieved by a single valve, when the ball valve is used as, for example, a conventional regional block valve, It is not necessary to install hot tapping or a pressure gauge, and the pit installation space can be made smaller, so the pit can be made smaller.

As a result, the construction cost required to install the regional block valve can be greatly reduced as compared with the conventional construction. In addition, for the gas supply system downstream of the installed ball valve, it is possible to shut off the gas and measure the flow rate for each system, which facilitates the formation of a conduit network in the gas supply system and further It will also be possible to easily manage the stable gas supply and security.

[0012]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 3 shows a ball valve of the present invention which is used in place of the regional block valve 11 described above, and which has an upstream intermediate pressure conduit 4 a and a downstream intermediate pressure conduit 4 which traverse the inside of the pit 12.
The valve main body 20 is interposed between the valve main body 20 and b. This valve body 2
0 is supported on the bottom of the pit 12 via the base 21,
The medium pressure conduits 4a and 4b are interposed so as to connect the upstream side and the downstream side.

Inside the valve body 20, a spherical valve body 22 is installed as is found in a normal ball valve. The valve body 22 has an upper stem shaft 24 and a lower stem shaft 23 at the upper and lower sides thereof. It is rotatably supported by the valve body 20 via. Further, the valve body 22 is provided with a through hole 25 having the same diameter as the inner diameters of the medium pressure conduits 4a and 4b connected to the valve body 20, and a straight pipe for disposing a flow rate detecting body 34 described later. The span of the part can be shared by the valve body 22. Further, in the valve body 22, the through hole 25 has an intermediate pressure conduit 4a,
The valve is in the open position when it is positioned in the same direction as the axis of 4b, and the valve is in the closed position when the through hole 25 is positioned at right angles to the axes of the intermediate pressure conduits 4a and 4b.

At the top of the valve body 20, flanges 26, 2 are provided.
A gear box 28 is connected via 7, and a worm gear (not shown) is rotated by a rotating operation of a geared motor 30 or a handle 31 attached to the gear box 28.
The upper stem shaft 24 thrustingly supported in the gear box 28
The valve body 22 is rotationally driven by the geared motor 30 or the handle 31 by meshing with the pinion gear 32 fixed to the.

The upper stem shaft 24 is formed as a hollow shaft, and a hollow passage 33 is formed in the shaft core.
Then, in the hollow passage 33, the flow rate detector 34 is provided at the lower end.
And the flow rate detection body 34 is inserted into the valve body 2
It is suspended in the second through hole 25 and comes into contact with the gas flow passing through the through hole 25. The upper end of the conduit 35 inserted into the hollow passage 33 is airtightly connected to the signal converter 37 connected to the gear box 28 so that the signal obtained from the flow rate detector 34 can be converted here. I have to.

The signal conversion unit 37 converts a physical signal (for example, a pressure signal) from the flow rate detector 34 into an electric signal, and the flow rate calculator 4 installed on the ground via the signal line 40.
Connected to 2. Here, the flow rate calculator 42 is configured as flow rate measuring means for calculating the gas flow rate based on the electric signal from the pressure detection unit 37.

Next, an example in which the flow rate measuring means attached to the ball valve is constructed as a differential pressure type flow meter and an example in which it is constructed as an electric type flow meter will be described with reference to the drawings.

FIG. 5 shows an example in which a conventionally known average value pitot tube 60 is used as a differential pressure type, and the average value pitot tube 60 is a dynamic pressure pitot tube 62 having many holes. And a static pressure pitot 61 form a double pipe. A dynamic pressure line 51 is connected to the inside of the dynamic pressure pitot 62 and a static pressure line 52 is connected to the inside of the static pressure pitot 61. The gas flow rate is measured from the pressure difference between the pressures.

Further, a configuration using an electrical type example instead of the above-mentioned differential pressure type example will be specifically described with reference to FIGS. 5 and 6. FIG. 5 is an explanatory diagram showing a configuration of a flow sensor (heat-sensitive type). The flow sensor measures a gas flow velocity by a temperature difference and detects a gas flow rate based on the result. As shown in FIG. 5A, a first thermistor 71, a heater 72, and a second thermistor 73 are arranged on a flat center chip 70. The center chip 70 thus configured is arranged in the center of the flow sensor 74 and installed inside the ball valve, as shown in FIG. 5B. When the gas flows in the direction of the arrow in the figure, the temperature of the second thermistor 73 downstream of the heater 72 becomes higher than the temperature of the first thermistor 71 upstream of the heater 72. It is configured to measure the flow velocity of gas.

FIG. 6 is an explanatory view showing the structure of the Karman vortex sensor, in which the vortex generator 80 is arranged inside the ball valve. Then, as shown in the figure, when gas flows in the direction of the arrow in the figure,
A Karman vortex train is generated downstream of the vortex generator 80, and the gas flow rate is detected by measuring the frequency of the Karman vortex train.

When the electric sensor described with reference to FIGS. 5 and 6 is used, the static pressure line and the dynamic pressure line which are required in the differential pressure type flow meter are not required, and the static pressure line due to an impact due to an earthquake or the like,
There is no concern about gas leakage due to damage to the dynamic pressure line. Further, in the above-described embodiments, the flow rate detector is described as a single body (one piece), but the present invention is not limited to this, and a plurality of flow rate detectors may be arranged in series and provided in the valve body, In this case, even if one flow rate detector fails, it can be detected by another flow rate detector, and as a result, maintenance of the flow rate detector becomes unnecessary.

[0022]

As described above, according to the ball valve of the present invention, gas shutoff and flow rate measurement can be achieved by a single valve. Therefore, this ball valve can be used as a conventional regional block valve, for example. When it is used as, it is not necessary to provide hot tapping or a pressure gauge as in the conventional case, and the pit installation space can be reduced, so that the pit can be downsized.

As a result, the pit where the ball valve is installed is
The pit needs only to be small enough to accommodate a ball valve, and its pit can be made much smaller than before, and the construction cost of the pit, which is indispensable when installing a regional block valve, can be greatly reduced. The economic effect is that the construction cost required to install the block valve can be greatly reduced.

Further, at the position where the ball valve is installed, the gas can be cut off and the flow rate can be measured for each of the consumption areas separately for each supply area. Therefore, the effect of facilitating the formation of a conduit network in the gas supply system can be obtained. Further, it is possible to obtain an effect such that stable supply of gas and safety management to each consumer can be easily performed.

[Brief description of drawings]

FIG. 1 is a schematic diagram illustrating a gas supply system.

FIG. 2 is a schematic view showing the installation form of a conventional regional block valve.

FIG. 3 is a vertical sectional view of a ball valve according to the present invention.

FIG. 4 is a sectional view of a flow rate detector using an average value Pitot tube.

FIG. 5 is an explanatory diagram of a flow sensor.

FIG. 6 is an explanatory diagram of a Karman vortex sensor.

[Explanation of symbols]

 1 Factory 2 High-pressure conduit 3 Governor station 4 Medium-pressure conduit 5 District governor 6 Low-pressure conduit 7 Consumer 8 Central monitoring center 10 Emergency shutoff valve 11 Regional block valve 12 Pit 13 Hot tapping 14 Pressure gauge 15 Flow rate detection sensor 16, 17 Impulsive pipe 18 Flow rate calculator 19 Valve 20 Valve body 21 Base 22 Valve body 23 Lower stem shaft 24 Upper stem shaft 25 Through hole 26, 27 Flange 28 Gabox 30 Geared motor 31 Handle 32 Pinion gear 33 Hollow passage 34 Flow rate detector 35 Pipeline 37 Signal Converter 40 Signal Line 42 Flow Rate Calculator 60 Average Value Pitot Tube 61 Static Pressure Pitot 62 Dynamic Pressure Pitot 70 Center Chip 71 First Thermistor 72 Heater 73 Second Thermistor 74 Flow Sensor 80 Vortex Generator

Claims (1)

[Claims] 1. A valve provided on a conduit of a gas conduit for shutting off gas or adjusting a flow rate, the valve having a spherical valve body having a through hole having the same diameter as an inner diameter of the conduit, and the valve body. It consists of a valve body that is rotatably supported and housed around a vertical axis. The through hole of the valve element is located coaxially with the gas conduit to allow gas flow, and the through hole is located at a right angle to the conduit to block the gas. Alternatively, in the case of a ball valve for adjusting the flow rate, the ball valve is provided with a flow rate detection sensor for a gas passing through the through hole of the valve body, and a signal obtained from the flow rate detection sensor is used as a base. A ball valve for a gas conduit, characterized in that it is provided with a flow rate calculation means for measuring the gas flow rate, and in addition to the original function of the valve, measurement of the gas flow rate can be achieved simultaneously by a single ball valve. .