JPS5831063Y2 - Gas meter with differential pressure generation mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gas meter equipped with a differential pressure generating mechanism that has an improved structure of a connecting pipe connected to an outlet pipe of a gas meter main body.

For large city gas consumers, it is necessary for gas suppliers to know the instantaneous flow rate in addition to the cumulative flow rate in order to set rates and stabilize supply and demand. The conventional method was to establish and measure the generation mechanism, but this method not only required the preparation of measuring instruments as accessories, but also resulted in a large loss of time.

The present invention was developed in view of the above circumstances, and its purpose is to connect a large venturi pipe that also serves as a connection pipe to the outlet pipe of the gas meter, and to combine it with a small venturi pipe button and a full pressure pipe. To provide at low cost a gas meter having a highly accurate differential pressure generation mechanism that has a small gas passage pressure loss, occupies a small area, is easy to install, and generates a large differential pressure.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

Reference numeral 1 in FIG. 1 denotes a gas meter main body, into which gas whose flow rate is to be measured is introduced via a gas inlet pipe 2, measured in a measuring chamber (not shown), and the cumulative flow rate is displayed through a flow rate indicator window. 3 and then led out from the gas outlet pipe 4.

A differential pressure generating mechanism 5 of the present invention is attached to this gas outlet pipe 4 with a union nut 6.

A threaded portion 8 is provided at the lower output of the differential pressure generating mechanism 5.
As shown in FIG. 2, various types of pipe fittings 9, 10, and 11 such as T-type, L-type, and straight type can be selectively used to freely connect the pipes.

Next, the differential pressure generating mechanism 5 is composed of a large bench lily tube 12, a total pressure tube 13, and a small bench lily tube 14, as shown in FIG.

The throat portion 1 is located approximately in the center of the large bench lily tube 12.
5 is formed, and a small bench lily tube 14 is supported concentrically at the center of the large bench lily tube 12 by supporting members 16 near this throat portion 15.

A through hole 18 is bored in the throat portion 17 of the small bench lily tube 14.

One end of a communication pipe 19 is fitted into the through hole 18, and the other end of the communication pipe 19 is connected to the inner wall 2 of the large bench lily pipe 12.
The gas passage 22 is fitted into a portion perpendicular to the gas flow path of the communication passage 22 that communicates with the outer wall 21 from the outside.

Furthermore, the large venturi tube 12 is provided with another communication passage 23 that also communicates from the inner wall 20 to the outer wall 21.
The above-mentioned full pressure pipe 13 is fitted into a portion of the communication path 23 parallel to the gas flow path.

In this way, the outer wall 21 of the large bench lily pipe 12 has an opening 24 for the static pressure P3 exerted on the throat portion 17 of the small bench lily pipe 14, and a total pressure P2 directed toward the vicinity of the inlet 25 of the large bench lily pipe 12 by the total pressure pipe 13. An opening 26 is formed therein.

A connecting pipe 29 in which a static pressure side passage 27 and a full pressure side passage 28 communicating with the openings 24 and 26 are provided is fixed to the outer wall 21 of the large bench lily tube 12.

Further, a protrusion 30 is formed on the peripheral edge of the outer wall 21 on the inlet 25 side of the canine Venturi tube 12, and the lower surface of the protrusion 30 and the upper end of the gas outlet pipe 4 provided in the main body 1 meet the backing 31. The airtightness is maintained by making contact through the

Name 32 is an instantaneous flowmeter.

Next, when gas flows from the gas meter 1 equipped with this differential pressure generating mechanism 5 into the large venturi pipe 12 at a pressure P1 as shown by arrow A and flows out from the lower part as shown by arrow B, a large By passing through the throat portion 15 of the bench lily tube 12 and the throat portion 17 of the small bench lily tube 14, pressure loss occurs and the pressure becomes P4.

During this time, the total pressure pipe 13 receives the total pressure of the inflowing gas and transmits it as high pressure P2 to the opening 26 of the outer wall 21 of the large bench lily pipe 12 via the communication passage 23.

In addition, the through hole 18 provided in the throat portion 17 of the small bench lily tube 14 receives the static pressure of the gas passing through, and is connected to the communicating tube 19 fitted into the through hole 18 and the communicating path provided in the large bench lily tube 12. 22 to the outer wall 2 of the large bench lily pipe 12
1 is transmitted to the opening 24 as a low pressure P3.

In this way, the above-mentioned total pressure P2 and static pressure P3 are transmitted to the connecting pipe 29 fixed to the outer wall 21 of the large bench lily pipe 12.

Therefore, the instantaneous flow meter 33 connected to this connecting pipe 29
The instantaneous flow rate can be displayed.

As explained above, in the present invention, a large venturi tube and a small bench lily tube are used together, so unlike a single venturi tube which requires a long expanded section, an extremely short and small expanded section is sufficient, reducing the occupied area. It has become possible to significantly reduce the size.

In Figure 4, which shows the experimental results of the relationship between flow rate, generated differential pressure button, and pressure loss for the differential pressure generation mechanism of the present invention, the passing pressure loss toward the maximum flow rate is reduced by the shortening of the pipe length. Since the aperture ratio was also increased, the resulting pressure difference was as small as 5 mm in the water column, and the differential pressure generated was 30 mm in the water column, which was 6 times the pressure loss.

Since such a large differential pressure is generated, measurement accuracy is improved, and in addition to displaying the instantaneous flow rate by connecting the above-mentioned instantaneous flowmeter to the connecting pipe, various applications are possible by attaching an alarm.

In addition, the large bench lily pipe can be used as a connecting pipe, with T-shape,
It was confirmed through experiments that it is possible to connect various types of pipe joints, such as L-shaped and straight pipe joints, and that there is no difference in the differential pressure generated even when these different pipe joints are used.

Therefore, the optimum piping can be selected for the conditions of the gas meter installation location, and the installation work is facilitated, and a gas meter equipped with a differential pressure generation mechanism that satisfies all of the objectives of the present invention can be provided at a low cost. can.

[Brief explanation of the drawing]

Fig. 1 is a front view of an embodiment of the present invention, Fig. 2 is a front view of an embodiment in which various pipe joints are connected, Fig. 3 is a longitudinal cross-sectional side view of the main parts, and Fig. 4 is an experiment. This is a graph of unity. 1...Main body, 4...Gas outlet pipe, 5.
...Differential pressure generation mechanism, 12...Large bench lily pipe, 13...Full pressure pipe, 14...Small bench lily pipe, 15...Large Venturi tube throat section, 17...Small Venturi tube throat section.

Claims (1)

[Scope of utility model registration request] A gas meter main body, a large bench lily pipe that is connected to the gas outlet pipe of this main body and formed integrally with a connecting pipe, and a total pressure pipe that is inserted into the communication passage of the large bench lily pipe and supported opposite the gas flow path. , also a gas meter equipped with a differential pressure generating mechanism consisting of a small bench lily tube supported concentrically at the center of this large bench lily tube.