JP2708701B2 - Wet gas meter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wet gas meter used for measuring a gas flow rate.

[0002]

2. Description of the Related Art As shown in FIGS. 6 to 9, a conventional wet gas meter includes a casing (90) and a drum (91) rotatably accommodated in the casing.

The drum (91) has a cylindrical drum body (1).
00) and four blade plates (101) for dividing the inside of the drum body into four measuring chambers (105).

Each of the blades (101) is provided with a partition plate (101).
a) and an outlet blade part (101b) and an inlet blade part (101c) provided on both sides of the partition part (101a) and bent in opposite directions.

[0005] Each of the blades (101) is provided inside the drum body (100) with an outlet blade (101b).
And the inlet blades (101c) face the open ends at both ends of the drum body (100), and are displaced in the circumferential direction, and are arranged inside the drum body in four measuring chambers (1).
05) is formed.

[0006] Also, on one end side of the drum cylinder (100),
A drum cover (102) is attached, and a gas conduit insertion hole (1) is provided at the center of the cover (102).
02a) is drilled. In addition, each blade (101)
In the center of the drum cylinder (1), a washer (103) is provided.
00) is mounted coaxially with the drum shaft (104).

The drum (91) has its drum shaft (1).
04) is held in a horizontal position, and the casing (9) is
0) so as to be rotatable around an axis.

At the time of use, the casing (90)
The sealing liquid (L) is injected into the inside to such an extent that the gas conduit insertion hole (102a) is disposed below the liquid level. In this state, gas is introduced into one end of the drum (91) via the gas conduit (91a). The introduced gas enters one measuring chamber (105) above the liquid level through the inlet formed by the blades at one end of the drum, and rotates the drum (91) by gas pressure. By the rotation of the drum (91), the gas is charged into the chamber and is replaced by the gas, so that the sealing liquid (L) passes through the outlet formed by the blades at the other end of the drum. Out of the weighing chamber. Further, when the drum (91) rotates and the outlet part appears on the liquid surface, the gas in the measuring chamber is released from the outlet part, and is replaced with the gas from the inlet part on one end side of the drum. The sealing liquid (L) flows. The gas discharged from the measuring chamber passes through the inside of the casing and is discharged to the outside from the exhaust hole (100b) in the upper wall of the casing.

On the other hand, the gas flowing from the gas conduit (91a) sequentially enters the measuring chamber (105) appearing on the liquid surface, and the same operation as described above is repeated.

As described above, the gas is discharged while being sequentially divided into the respective measuring chambers (105), and one rotation of the drum (91) discharges the gas for the four measuring chambers. Therefore, the gas flow rate can be measured by integrating the number of rotations of the drum (91).

[0011]

As described above, the drum (91) is rotated by the pressure of the gas flowing into the measuring chamber (105). The rotational moment at this time is obtained based on the product of the distance from the rotational center position of the drum (91) to the center of gravity of the pressure-receiving liquid surface in the measuring chamber and the load applied to the liquid surface by the gas differential pressure. For this reason, the rotational moment decreases due to the position of the center of gravity of the pressure-receiving liquid surface approaching the center of rotation, or a decrease in gas pressure or a decrease in the area of the pressure-receiving liquid surface.

On the other hand, in order to reduce the capacity (drum capacity) of the drum measuring section defined by the total capacity of the measuring chamber (105), for example, it is conceivable to reduce the size of the drum. The distance to the position of the center of gravity of the pressure receiving liquid surface in the measuring chamber is shortened, and the pressure receiving liquid surface area is also reduced. For this reason, the rotational moment becomes small, and a predetermined rotational force cannot be obtained,
Rotational unevenness occurs, resulting in a decrease in measurement accuracy.
Further, when the drum capacity is small, the dimension between the blades is also small, so that the influence of the surface tension of the sealing liquid (L) acting on the blades (101) increases, and rotation unevenness and the like occur as described above. As a result, the measurement accuracy is reduced.

[0013] Under these circumstances, the conventional wet gas meter described above cannot reduce the drum capacity while maintaining high accuracy. Therefore, conventionally, a drum having a large drum capacity, specifically, a drum (9
The gas flow rate during one rotation of 1) is 1.0 liter (l / l).
rev. Gas meters with drums) were commonly used.

However, in such a gas meter having a large drum capacity, the measurement time is long when a small amount of gas is measured, and the obtained measurement value has low accuracy.
There is a problem that it is difficult to detect a trace leak of gas.

Conventionally, the capacity of the drum is 0.1 mm.
Although a relatively small capacity of 5 (l / rev.) Is also produced, for the reasons described above, large unevenness in rotation occurs during use and high measurement accuracy cannot be obtained. 1.0 (l / rev.)
Is currently used.

On the other hand, a soap film flow meter is sometimes used for measuring a trace amount of gas. However, the soap film flow meter cannot measure gas permeating through the soap film first, and secondly can measure gas passing through the soap film. There is a problem inherent to a soap film flow meter, such as that it is only possible to measure a temporary flow rate and it is difficult to accurately measure an integrated flow rate. However, it goes without saying that this problem can be solved by using a wet gas meter.

The present invention solves the above-mentioned problems of the prior art and, while maintaining high measurement accuracy, can reduce the capacity of the drum measuring section with a high torque, thereby making it possible to reduce the amount of trace gas with high accuracy and shortness. It is an object of the present invention to provide a wet gas meter drum and a wet gas meter that can be measured in time.

[0018]

In order to achieve the above object, a wet gas meter according to the present invention has an inner cylinder disposed coaxially inside an outer cylinder and an annular space between the two cylinders. It is constant from one end to the other along the axial direction.
The two annular blades spirally extending at the lead angle are provided at different positions in the circumferential direction, so that the annular space is provided.
The distance between them is kept constant from one edge to the other.
A drum formed with two spiral gas measuring chambers separated by the two blades, and a casing in which the drum is rotatably accommodated. The gas that has flowed in flows out of the other end of the drum, and a gas path that is discharged to the outside through the inside of the casing is formed. Outside the drum in the casing, the sealing liquid injected into the casing is formed. The gist is to provide a balance member for reducing the liquid surface area.

[0019]

In the wet gas meter according to the present invention, the drum has a spiral shape in which two blades are displaced in the circumferential direction in an annular space between the outer cylinder and the inner cylinder disposed therein. , Two spiral gas measuring chambers are formed. In this configuration, since the measuring chamber is formed in the outer peripheral portion of the drum, the distance from the center of rotation to the position of the center of gravity of the pressure-receiving liquid surface in the measuring chamber is long, and a large rotational moment is obtained. Furthermore, since the number of blades used is specified to be two, the size between the blades can be kept large as compared with, for example, the existing four blades, and the surface tension of the sealing liquid acting on the blades can be reduced. The effect can be reduced.

Further, since the balance member for reducing the liquid surface area of the sealed liquid is provided in the outflow gas chamber in the casing accommodating the drum, the pressure receiving liquid surface area of the outflow gas chamber is reduced. Therefore, the ratio of the pressure receiving liquid surface area of the inflow side gas chamber to the area becomes large. Therefore, the fluctuation of the liquid level position of the inflow-side gas chamber, that is, the gas metering replacement liquid level is reduced by the hydraulic principle.

[0021]

1 is a side sectional view showing a wet gas meter according to an embodiment of the present invention. As shown in the figure, the gas meter has a casing (10) and a drum (20) housed therein.

As shown in FIGS. 1 to 3, the drum (2)
0) is an outer cylinder (21), an inner cylinder (22) arranged coaxially inside the outer cylinder (21), and two sheets arranged in an annular space between the two cylinders. And a blade plate (23).

A drum cover (24) for storing inflow gas is mounted on one end opening surface of the outer cylinder (21), and a gas conduit is inserted into the center of the cover (24). A hole (24a) is drilled.

The inner cylindrical body (22) is formed shorter than the outer cylindrical body (21), and end face members (25) and (26) are attached to both axial openings. One end member (25) has a central portion, that is, a drum (2).
0) is formed coaxially with the drum shaft mounting hole (25a), and around the mounting hole (25a), when the gas meter is in operation, the flow of gas into the inner cylinder (22) and the sealing of the liquid ( Four openings (25b) allowing passage of L) are formed.

A drum shaft mounting hole (26a) is formed in the other end member (26) in the same manner as described above, and around the mounting hole (26a), the passage of the sealing liquid is allowed. A through hole (26b) is formed.

As shown in FIG. 4, each of the two blades (23) is formed in a substantially C-shape when viewed from the front, and the inner peripheral surface of the outer cylinder (21) and the inner cylinder (22) are formed. In the annular space between the drum and the outer peripheral surface, a certain amount of
It is arranged so as to extend spirally at a card angle . The blades (23) are arranged so as to be shifted from each other by 180 degrees in the circumferential direction, so that two blades are provided in an annular space between the outer cylinder (21) and the inner cylinder (22). Board (23)
(23), the mutual interval is constant from one edge to the other edge
The two blades (2
A spiral measuring chamber (3) partitioned at equal intervals by 3)
0) are formed, and each measuring chamber (30) is
An opening between the blades at one end and the other end of the drum,
That is, it is opened by the inlet part (30a) and the outlet part (30b).

The drum (20) thus configured is
In the present embodiment, each of the constituent members is formed of a transparent hard synthetic resin such as vinyl chloride and joined by an adhesive. In the present invention, the drum (2
The material of each component in 0) is not particularly limited, and may be formed of metal or the like. Also, the joining method is not limited to the method using an adhesive, and a method for joining by, for example, soldering or welding can be used according to the material of each component.

As shown in FIG. 1, the drum shaft (27)
The gas passage tube insertion hole (24a) of the drum cover (24) and the drum shaft mounting hole (25) of the end face members (25) and (26) are arranged on the axis of the drum (20).
a) While being inserted through (26a),
c).

The casing (10) comprises a box-shaped casing body (11) having an open upper end, and a casing cover (12) for closing the upper end opening.

Then, with the drum (20) housed in the casing (10), both ends of the drum shaft (27) are rotatably attached to the side wall of the casing (10).

The upper wall of the casing cover (12) has a gas inlet (12) corresponding to one end of the drum (20).
a) is formed, and a gas outlet (12b) is formed corresponding to the other end of the drum (20).

Further, as shown in FIG. 5, on the inner surface of the peripheral wall of the casing (10), the liquid of the sealing liquid (L) corresponds to the liquid level of the sealing liquid (L) injected into the casing. A balance plate (40) for reducing the surface area is attached. In FIG. 5, (50) indicates an overflow mechanism.

In the casing (10), a gas conduit (13) whose upper end is connected to the gas inlet (12a) is disposed, and an upwardly projecting branch branched from the gas conduit (13). Branch pipe (13a) is drum cover (24)
And is inserted upward into the drum (20).

In this wet gas meter, a predetermined amount of the sealing liquid (L) is injected into the casing (10) at the time of use. At this time, the liquid level is higher than the through liquid level, that is, the gas conducting tube insertion hole (24a) of the drum cover (24) and the through hole (26b) of the other end member (26) are arranged below the liquid surface. The branch pipe (13) of the gas conduit (13)
a) and the opening (25) of the one end member (25).
b) The upper part is set so as to be placed on the liquid surface.

Further, by injecting the sealing liquid (L), an inflow-side gas chamber (14a) is formed in the casing (10) by the space inside the drum except for the measuring chamber, and the outflow-side gas chamber is formed by the space outside the drum. A chamber (14b) will be formed. Further, due to the presence of the balance plate (40), the liquid surface area of the outflow-side gas chamber (14b) is reduced as compared with the case where the balance plate (40) is not provided. In this embodiment, the liquid surface area (Si) of the inflow-side gas chamber (14a) shown by oblique lines to the left in FIG.
The ratio with the liquid surface area (So) of b) is set to about 1: 1.

In this state, the gas is supplied to the gas inlet (1a) of the inflow gas chamber (14a) of the drum (20).
2a) and pumping through the gas conduit (13),
As shown in FIG. 1, the gas pressure (14)
The liquid level in a) decreases and the outlet gas chamber (14)
The liquid level of b) rises, and each liquid level is kept constant.

On the other hand, the gas pumped into the inflow-side gas chamber (14a) is introduced into the measuring chamber (30) located above the liquid surface of the two measuring chambers (30) into the inlet portion (one end side of the drum). 30
a) and the drum (20) is rotated by the gas differential pressure.

With the rotation of the drum (20), the gas fills the inside of the measuring chamber (30), and the sealed liquid (L) is replaced with the gas so that the sealing liquid (L) is discharged from the outlet (at the other end of the drum). 3
0b). When the rotation of the drum (20) further proceeds, the measuring chamber (30) submerges from the inlet (30a), and after the inside is once sealed, the outlet (30b) at the other end of the drum rises above the liquid level. Appears in Further, as the measuring chamber (30) is submerged, the gas in the chamber is discharged into the casing through the outlet (30b) so as to be replaced with the sealing liquid (L), and the gas is released from the casing upper wall. Through the gas outlet (12b).

On the other hand, with the rotation of the gas measuring chamber (30), the other gas measuring chamber (30) appears on the liquid surface, and the same operation as described above is performed on this measuring chamber (30). Is performed, and this operation and the above operation are alternately repeated and continuously performed.

As described above, the gas is discharged while being divided into the measuring chambers (30) sequentially, and the gas of two measuring chambers is discharged by one rotation of the drum (20). Therefore, the gas flow rate can be measured by integrating the number of rotations of the drum (20).

According to this wet gas meter, the drum (20) having the measuring chamber (30) formed in the annular space between the outer cylinder (21) and the inner cylinder (22) is provided. The measuring chamber (30) is formed in the portion, the distance from the center of rotation of the drum (20) to the position of the center of gravity of the pressure-receiving liquid surface in the measuring chamber becomes longer, a large rotational moment can be obtained, and sufficient rotational force can be obtained. Can be obtained. Further, since the number of used blades (23) is specified to be two, the size between the blades becomes larger as compared with, for example, those of the existing four blades, and the sealing acting on the blades (23) is performed. The effect of the surface tension of the liquid (L) can be reduced. As described above, the influence of the surface tension on the blade plate (23) can be reduced, and a sufficient rotational force can be applied to the drum (20), so that the capacity of the drum measuring section can be reduced while maintaining high accuracy. Therefore, the trace gas can be measured with high accuracy and in a short time.

For reference, the drum (20) of this embodiment
The outer cylinder (21) has the same dimensions as the drum body of the conventional drum, and the dimensions of the inner cylinder (22) are adjusted so that the gas flow rate becomes 0.25 (l / rev.). It is formed so that it becomes. In this drum (20), high measurement accuracy can be maintained and a small amount of gas can be obtained with high accuracy and short time, although the drum capacity is reduced to ４ to １ ／ of the conventional drum. We could weigh in time.

Further, in this embodiment, since the drum has the same size as the conventional one, it is not necessary to manufacture a dedicated casing. For this reason, there is no need to manufacture a casing according to the dimensions of the drum, and since a conventional casing can be used as it is, while reducing costs,
A flow meter capable of measuring a trace gas with high accuracy can be provided. Furthermore, since the gas meter of the present embodiment can measure a trace amount of gas with high accuracy, it can be used in place of the soap film flow meter, thereby reducing the measurement of only the instantaneous flow rate to the integrated flow rate. Measurement can be performed.

In this embodiment, the balance plate (40)
Is provided, it is possible to further improve the accuracy. That is, since the volume of the gas to be measured is determined by the liquid level of the inflow-side gas chamber (14a), the smaller the fluctuation of the gas measurement replacement liquid level, the higher the accuracy. Therefore, as in the present embodiment, the liquid surface area (So) of the outflow-side gas chamber (14b) is reduced by the balance plate (40), so that the liquid level of the inflow-side gas chamber (14a) with respect to the area (So) is reduced. When the ratio of the surface area (Si) is increased, the fluctuation of the gas metering liquid level is reduced by the principle of hydraulic pressure, and high measurement accuracy can be obtained.

In this embodiment, the inner cylinder (2
Since the opening (25b) and the through-hole (26b) that allow the passage of the sealing liquid are formed in the end surface members (25) and (26) of 2), they pass through the measuring chamber (30) below the liquid level. The sealing liquid moved from the drum inlet side to the outlet side is opened (25
b), it is possible to smoothly return to the inlet side of the drum (20) through the inside of the inner cylinder and through the through hole (26b), and it is possible to prevent a sharp liquid level fluctuation and a liquid flow from occurring, and to achieve a high measurement accuracy. Can be obtained. Further, through the opening (25b) of the one end surface member (25), the inner cylindrical body (22)
Since the gas flows into the inside of the drum, the inflowing gas generates buoyancy in the inner cylinder (22), thereby reducing the load on the inner cylinder (22) acting on the bearing of the drum shaft (27). it can.

In the above embodiment, the ratio between the inflow side liquid surface area (Si) and the outflow side liquid surface area (So) is set to 1 to 1 by the balance plate (40). If the ratio of the liquid surface area on the outflow side is set to be smaller than the area ratio (1: 3 to 5), that is, if the ratio is less than 1: 3, the above-described effect can be obtained. If it is below, a remarkable effect can be obtained.

[0047]

According to the wet gas meter of the present invention,
Since the measuring chamber is formed in the annular space between the drum and the outer cylinder and the inner cylinder, the measuring chamber is formed in the outer peripheral portion of the drum,
The distance from the center of rotation to the position of the center of gravity of the pressure-receiving liquid surface in the measuring chamber becomes longer, so that a large rotational moment can be obtained and a sufficient rotational force can be obtained. further,
Since the number of blades used is specified as two, the size between the blades is larger than that of existing four blades, for example, and the effect of the surface tension of the sealing liquid acting on the blades is reduced. can do. In this way, the effect of surface tension on the blades can be reduced, and sufficient rotational force can be obtained.
While maintaining high accuracy, it is possible to reduce the capacity of the drum metering section, thereby making it possible to accurately measure a trace amount of gas in a short time. Further, since the outflow side gas chamber in the casing accommodating the drum is provided with a balance member for reducing the liquid surface area of the sealed liquid, the pressure receiving liquid surface area of the outflow side gas chamber is reduced, and the area thereof is reduced. , The ratio of the pressure-receiving liquid surface area of the inflow-side gas chamber becomes large. For this reason, the fluctuation of the liquid level position of the inflow side gas chamber, that is, the gas metering replacement liquid level is reduced by the hydraulic principle,
The effect that the measurement accuracy can be improved can be obtained.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a wet gas meter according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view showing a drum used in the gas meter of the embodiment.

FIG. 3 is a front and back side view showing the drum with its drum cover removed.

FIG. 4 is a front view showing a blade plate applied to the drum.

FIG. 5 is a schematic plan view showing the gas meter of the embodiment with its casing cover removed.

FIG. 6 is a side sectional view showing a drum of a conventional wet gas meter.

FIG. 7 is a perspective view showing the conventional drum in a state where a part of the drum body is separated.

FIG. 8 is a front view showing the conventional drum with its cover removed.

FIG. 9 is a perspective view showing a blade plate of the conventional drum.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Casing 20 ... Drum 21 ... Outer cylinder 22 ... Inner cylinder 23 ... Blade plate 30 ... Measuring chamber 40 ... Balance plate L ... Liquid sealing Si, So ... Liquid surface area

Claims (1)

(57) [Claims] An inner cylindrical body is coaxially arranged inside an outer cylindrical body, and a constant lead angle extends from one end side to the other end side along an axial direction in an annular space between the two cylindrical bodies. The two blades extending spirally are provided at positions shifted from each other in the circumferential direction so that the annular space has one edge from the other edge.
A drum formed with two spiral gas measuring chambers partitioned by the two blades , the intervals of which are kept constant at a distance from each other ; and a casing in which the drum is rotatably housed. A gas path into which the gas that has flowed into the gas measuring chamber from one end side flows out from the other end side of the drum and is discharged to the outside through the inside of the casing is formed. A wet gas meter comprising a balance member for reducing the liquid surface area of the sealed liquid injected therein.