JP2019124653A - Gas meter - Google Patents

Abstract

To provide a gas meter that can measure the flow rate of a gas accurately with a simple configuration.SOLUTION: There is provided a gas meter 1 for measuring the flow rate of a gas which has entered a housing 11 from a gas entrance port 21. The gas meter includes: a gas chamber 13, communicated with the gas entrance port 21 and serving as an internal space of the housing 11; a flow rate measurement device 23 for measuring the flow rate of gas which has entered from the gas chamber 13; and a cut-off valve 25, closing the gas entrance port 21 and cutting off the entrance of the gas from the gas entrance port 21 to the gas chamber 13; and an explosion prevention motor 26 in the gas chamber 13, the motor closing or opening the cut-off valve 25.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a gas meter that measures the flow rate of gas.

  Usually, a gas meter is provided with a gas inlet connected to a gas supply and a gas outlet connected to a gas device such as a combustor. Thereby, in the gas meter, the flow rate can be measured in the process of passing the gas flowing in from the gas inlet into the series of gas flow paths from the gas inlet to the gas outlet.

  And as a conventional gas meter which was mentioned above, it is indicated by patent documents 1, for example.

Patent No. 5369940 gazette

  The gas flow path in the above conventional gas meter includes a flow rate measuring device for measuring the flow rate of gas, a supply flow path connecting the gas inlet and the upstream side of the flow rate measuring device, and the gas outlet and the downstream side of the flow rate measuring device And the discharge flow path which connects with.

  However, in the above-described conventional gas meter, since the supply flow channel and the flow rate measuring device are connected to be orthogonal to each other, the gas flowing in the supply flow channel changes its flow direction rapidly immediately before the flow rate measuring device. Do. As a result, in the flow of the gas supplied to the flow rate measuring device, the vortex flow and the turbulent flow are easily generated, and the measurement accuracy of the gas flow rate may be lowered.

  This invention solves the said subject, and it aims at providing the gas meter which can measure the flow volume of gas with high precision by simple structure.

  The gas meter according to the present invention is a gas meter that measures the flow rate of gas flowing into the housing from the gas inlet, and is in communication with the gas inlet and flows from the gas chamber serving as the internal space of the housing and the gas chamber A flow rate measuring means for measuring the flow rate of gas, a shutoff valve for closing the gas inlet and blocking the flow of gas from the gas inlet to the gas chamber, and an explosion-proof type disposed in the gas chamber for opening and closing the shutoff valve And a motor.

  According to the present invention, the flow rate of gas can be measured with high accuracy by a simple configuration.

It is a front perspective view of a gas meter concerning Embodiment 1 of this invention. It is a front view of the gas meter concerning Embodiment 1 of this invention. It is the III-III arrow sectional drawing of FIG. It is a principal part expanded sectional view of FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

Embodiment 1
FIG. 1 is a front perspective view of a gas meter according to Embodiment 1 of the present invention. FIG. 2 is a front view of a gas meter according to Embodiment 1 of the present invention. FIG. 3 is a cross-sectional view taken along the line III-III in FIG. FIG. 4 is an enlarged sectional view of a main part of FIG. The arrows shown in FIGS. 1 to 4 indicate the flow of gas.

  As shown in FIGS. 1 to 3, the ultrasonic gas meter 1 includes a housing 11 and a lid member 12. The housing 11 and the lid member 12 constitute the main body of the gas meter 1. The housing 11 is disposed on the back side of the gas meter 1, and the lid member 12 is disposed on the front side of the gas meter 1.

  The housing 11 has an opening 11a, and the opening 11a opens toward the front side. The lid member 12 is fitted in the housing 11 so as to close the opening 11 a. At this time, a seal member (not shown) is interposed between the housing 11 and the lid member 12, and the seal member seals the gap between them. As described above, the gas meter 1 has a hollow structure in which the housing 11 and the lid member 12 are fitted to each other, and the sealed space serving as the internal space thereof is the gas chamber 13 filled with the gas to be measured.

  Inside the housing 11, a gas inlet 21, a gas outlet 22, a flow rate measuring device 23, a communication member 24, a shutoff valve 25, and an explosion-proof motor 26 are housed.

  The gas inlet 21 and the gas outlet 22 are cylindrical, and penetrate the upper portion of the housing 11 and project outward from the upper surface of the housing 11. The gas inlet 21 allows the gas supplied from the gas supply source to flow into the gas chamber 13. The gas outlet port 22 allows the gas whose flow rate has been measured by the flow rate measuring device 23 to flow out toward a gas device such as a combustor.

  As shown in FIGS. 1 to 4, the gas inlet 21 has a gas inflow passage 21 a inside. The downstream side open end 21 b of the gas inflow passage 21 a is open upward on the back side of the gas meter 1 and is in communication with the gas chamber 13. That is, the gas supplied to the gas inflow port 21 passes through the gas inflow passage 21 a and flows in from the downstream side open end 21 b toward the upper side of the back side of the gas chamber 13.

  As shown in FIGS. 1 to 3, the flow rate measuring device 23 serves as a flow rate measuring means, and measures the flow rate of the gas flowing from the gas chamber 13. The flow rate measuring device 23 has a tubular shape, and has a measurement flow path 23a inside. The upstream side open end 23 b of the measurement flow path 23 a communicates with the gas chamber 13, while the downstream side open end 23 c of the measurement flow path 23 a communicates with the communication member 24.

  Further, a plurality of rectifying plates 23d are provided in the measurement flow path 23a. The straightening vanes 23d extend along the gas flow direction, and are arranged to overlap in the width direction of the measurement flow path 23a. Furthermore, in the flow rate measuring device 23, a pair of ultrasonic sensors 23e that enable transmission and reception of ultrasonic waves are provided. The pair of ultrasonic sensors 23e face the measurement flow path 23a, and are provided on the upstream side and the downstream side in the gas flow direction.

  Then, the flow rate measuring device 23 measures the flow rate of the gas based on the ultrasonic wave propagation time between the pair of ultrasonic sensors in the process of the gas flowing in from the gas chamber 13 passing through the measurement flow path 23a. , Output the integrated flow rate.

  That is, the gas meter 1 once introduces the gas flowing in from the gas inlet 21 into the measurement flow path 23a after filling the gas chamber 13 once instead of directly introducing it into the measurement flow path 23a. As a result, the flow of the gas introduced from the gas chamber 13 to the flow rate measuring device 23 has no abrupt direction change as compared with the flow of the gas directly introduced from the gas inlet 21 to the flow rate measuring device 23. Is a small flow. Therefore, the flow rate measuring device 23 can measure the flow rate of the gas with high accuracy.

  As shown in FIGS. 1 and 2, the communication member 24 is a cylindrical bellows member, and communicates the downstream opening end 23c of the measurement flow passage 23a with the gas outlet 22. . That is, the communication member 24 allows the communication between the downstream opening end 23 c of the flow rate measuring device 23 and the upstream opening end of the gas outlet 22 by absorbing the positional deviation by the expansion and contraction of the bellows. Can.

  As shown in FIGS. 1 to 4, the shutoff valve 25 and the explosion-proof motor 26 are provided on the downstream side of the gas inlet passage 21 a of the gas inlet 21. The shutoff valve 25 is disposed in the gas inflow passage 21a, and opens and closes the downstream side open end 21b from the inside of the gas inflow passage 21a. The explosion-proof motor 26 is provided outside the gas inflow passage 21a, that is, on the outer surface of the gas inlet 21, and moves the shutoff valve 25 forward or backward with respect to the downstream open end 21b to open the shutoff valve. Open and close 25

  That is, since the explosion-proof type motor 26 is disposed in the gas chamber 13 filled with gas, even if it is used in a hazardous gas atmosphere such as flammable gas and flammable vapor, it is possible to ignite, ignite, explode, etc. Is a motor that does not occur. Thus, the explosion-proof motor 26 has a sealed structure in which gas, dust and the like do not enter inside.

  For example, the shutoff valve 25 is advanced by the positive rotation drive of the explosion-proof type motor 26 to close the downstream side open end 21b of the gas inlet 21 in emergency use such as abnormal gas use and earthquake occurrence. Thereby, the inflow of gas from the gas inlet 21 to the gas chamber 13 is shut off. The shut-off valve 25 is retracted by the reverse rotation drive of the explosion-proof motor 26 during normal use of the gas meter 1, that is, at the time of flow rate measurement, to open the downstream side open end 21b of the gas inlet 21. Thereby, the inflow of gas from the gas inlet 21 to the gas chamber 13 is opened.

  Therefore, when measuring the flow rate of gas using the gas meter 1, first, the gas supplied from the gas supply source temporarily flows into the gas chamber 13 from the gas inlet 21. Subsequently, the gas flowing into the gas chamber 13 is introduced into the measurement flow path 23 a of the flow rate measurement device 23. Thus, the flow rate measuring device 23 measures the flow rate of the gas passing through the measurement flow path 23a using ultrasonic waves. Then, the gas whose flow rate is measured by the flow rate measuring device 23 passes through the communication member 24 and flows out from the gas outlet 22 toward the gas device.

  Further, in the gas meter 1, the flow path connecting the gas inlet 21 and the flow rate measuring device 23 is eliminated, and the supplied gas is allowed to flow from the gas inlet 21 into the gas chamber 13, and then the gas chamber 13 are introduced into the flow rate measuring device 23. Thereby, since the gas meter 1 can prevent a rapid directional change at the time of introduction to the flow rate measuring device 23 of gas, the measurement accuracy of the gas flow rate by the flow rate measuring device 23 can be improved.

  Furthermore, in the gas meter 1, the flow path connecting the gas inlet 21 and the flow rate measuring device 23 is eliminated, and the motor for opening and closing the shutoff valve 25 is an explosion-proof motor 26. It can be simplified.

  That is, by eliminating the flow path communicating the gas inlet 21 with the flow rate measuring device 23, the internal space formed by the housing 11 and the lid member 12 becomes the gas chamber 13 filled with gas. At this time, since the motor for opening and closing the shut-off valve 25 is the explosion-proof motor 26, the state where the explosion-proof motor 26 is exposed to the dangerous gas atmosphere without surrounding it and isolating it from the dangerous gas atmosphere Can be installed. As a result, it is not necessary to install a cover member or the like for protecting the explosion-proof motor 26 from the dangerous gas atmosphere, and therefore, the number of parts constituting the gas meter 1 and the manufacturing cost can be reduced.

  As mentioned above, according to the gas meter 1 which concerns on Embodiment 1 of this invention, it is the gas meter 1 which measures the flow volume of the gas which flowed in in the housing | casing 11 from the gas inflow port 21, Comprising: It communicates with the gas inflow port 21. The gas chamber 13 serving as the internal space of the housing 11, the flow rate measuring device 23 for measuring the flow rate of gas flowing from the gas chamber 13, and the gas inlet 21 are closed. In the simple configuration, the flow rate of gas is measured with high accuracy by providing the shutoff valve 25 for blocking the flow of gas and the explosion-proof motor 26 disposed in the gas chamber 13 and opening and closing the shutoff valve 25. be able to.

  In the present invention, within the scope of the invention, modification of any component of the embodiment or omission of any component of the embodiment is possible.

Reference Signs List 1 gas meter 11 housing 11a opening 12 cover member 13 gas chamber 21 gas inlet 21a gas inlet passage 21b downstream opening end 22 gas outlet 23 flow measuring device 23a measurement flow path 23b upstream opening end 23c downstream Open end 23d Rectifying plate 23e Ultrasonic sensor 24 Connecting member 25 Cut-off valve 26 Explosion-proof type motor

Claims (1)

A gas meter for measuring the flow rate of gas flowing into a housing from a gas inlet,
A gas chamber in communication with the gas inlet and serving as an internal space of the housing;
Flow rate measuring means for measuring the flow rate of the gas flowing in from the gas chamber;
A shutoff valve for closing the gas inlet and for blocking the flow of gas from the gas inlet to the gas chamber;
A gas meter comprising: an explosion-proof motor disposed in the gas chamber and opening and closing the shutoff valve.

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