JP2543407B2 - Liquefied gas container remaining amount indicator - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a residual quantity indicator for indicating the residual quantity of a container that stores a liquefied gas such as liquid oxygen.

[Conventional technology]

Conventionally, various devices are known as devices for indicating the remaining amount of the seed liquefied gas container.

For example, in a liquefied gas container used for home oxygen therapy using liquid oxygen, a platform scale is applied to display the remaining amount by the weight of liquid oxygen, or the pressure at the bottom of the container is the gas above the container. There is known a “differential pressure type liquid level gauge” or the like that utilizes the fact that the weight of the liquefied gas is higher than the pressure of the part to convert the differential pressure between the two into a liquefied gas amount and displays the converted amount.

In addition, as an industrial liquid level gauge, a "float type liquid level gauge" that displays a liquid level using a float is known. An example of the "float type liquid level gauge" will be described with reference to FIG.

In FIG. 4, (1) is a liquefied gas container, which has an outer tank (2) and an inner tank (3), and both tanks (2) and (3).
The space (4) between them is evacuated. The upper opening of the liquefied gas container (1) is sealed by a lid (5), and the lid (5) has a pipe (6) for supplying and discharging the liquefied gas, a pipe (7) for discharging the gas, and a transparent scale. An attached gauge tube (8) is attached. Inside the inner tank (3), there is a display piece (9) at the top.
A rod-shaped float (10) made of light metal with the attached is provided in the vertical direction. This float (10) is made of a low temperature resistant metal that can withstand the temperature of the liquefied gas, and in order to compensate for the insufficient buoyancy, it is lifted by a reinforcing spring (11) whose one end is fixed to the gauge pipe (8). is there. The float (10) extends over almost the entire length of the inner tank (3) as shown. Note that (12) is the liquid surface of the liquefied gas.

When the liquid level (12) in the liquefied gas container (1) fluctuates, the float (10) moves up and down due to the difference in specific gravity between the liquefied gas and the float (10). The remaining amount can be confirmed by visually observing from outside.

In addition, in order to make the liquid level gauge compact, the buoyancy is adjusted so that the movement amount of the float (10) becomes small even if the liquid level (12) largely changes.

The float (10) used in this type of liquid level gauge is not a hollow body which is advantageous in terms of buoyancy, but has a closed structure, which is due to the following reasons.

For example, in the case of liquid oxygen, the liquefaction temperature of liquid oxygen is −
Since the temperature is 180 ° C, the temperature of the float (10) drops to -180 ° C when liquid oxygen is present in the container and is immersed, and the temperature rises to room temperature when liquid oxygen is not present in the container. To rise. Therefore, the difference in temperature applied to the float (10) is about 200 ° C. Therefore, the float (1
If (0) is a hollow body, the gas inside the hollow body repeatedly expands and contracts, so a structure must be able to withstand this, but it is extremely difficult to achieve this both in terms of technology and cost. Because.

In addition, if the airtightness inside the hollow body is incomplete, the liquefied gas may intrude into the hollow body due to the decrease in atmospheric pressure. In this state, when the float (10) returns to room temperature, the liquefied gas inside expands. It is extremely dangerous because it expands about 800 times in the case of liquid oxygen.

[Problems to be Solved by the Invention]

As described above, the float type liquid level gauge displays a change in the buoyancy caused by a change in the amount of the portion of the float (10) immersed in the liquefied gas as the remaining amount of the liquefied gas. The float (10) that senses the quantity must be in the form of a long rod, and at least the inner tank (3)
It is necessary to have a length corresponding to the height of the liquid surface at the time of full filling from the bottom of the above, and moreover, all the parts in contact with the liquefied gas must have the same diameter and be uniform.

In addition, the conventional level gauge can know the change of the remaining amount of the liquefied gas with time, but the user himself needs to confirm that the predetermined remaining amount has been reached. There is a risk that

The present invention has been made in view of such conventional circumstances, and an object thereof is to provide a remaining amount indicator for a liquefied gas container, which can automatically notify that the liquefied gas has reached a predetermined remaining amount. Is to provide. Still another object of the present invention is to ignite vaporized liquefied gas by sparks generated when the switch is turned on and off, even if the liquefied gas is a flammable gas such as LPG or acetylene gas. There is no safe liquefied gas container residual quantity indicator.

Another object of the present invention is to provide a remaining amount indicator of a liquefied gas container that can accurately issue an alarm without exerting an unreasonable force on the liquefied gas remaining amount sensing portion even if the container is tilted. Is.

[Means for solving the problem]

In order to achieve the above object, the present invention takes the following technical means.

That is, a main body mounted so as to seal the inside of the liquefied gas container, a shaft housed in the liquefied gas container and vertically movably attached to the main body, a magnet fixed to the upper end of the shaft, A clogged metal float attached near the lower end of the shaft, and a reinforcing spring that fixes one end to the main body and the other end to a position not immersed in liquefied gas at the top of the shaft to help the buoyancy of the float. , A liquefied gas container which is sealed in the main body and is operated by a magnet switch of the liquefied gas residual amount detecting means, and a liquefied gas residual amount detecting means comprising a magnet switch which is turned on or off by the approach of the magnet. And a warning means provided outside, wherein the float of the liquefied gas residual amount sensing means is exposed to a certain amount from the liquefied gas. When the shaft is lowered by and the influence of the magnet fixed on the upper end of the shaft disappears, the magnet switch is actuated to activate the alarm means, thereby providing a residual quantity indicator of the liquefied gas container. .

The remaining amount detecting means is slidably held by the connecting member having a concave spherical surface portion fixed to the opening of the lower opening chamber in which the magnet provided in the main body moves up and down. It is preferable to provide a tubular body having a spherical portion, and the shaft is attached to the tubular body so as to be vertically movable.

[Action]

Since it is configured as described above, when the shaft is inserted into the liquefied gas container and the main body is attached to the liquefied gas container,
The float is entirely immersed in the liquefied gas and is located near its bottom. The position of the float is set according to the remaining amount of liquefied gas for which an alarm should be issued.

When the use of liquefied gas is started, the buoyancy hardly changes while the float is submerged in the liquefied gas, the magnet switch provided in the liquefied gas remaining amount detection means maintains the initial state, and the alarm I can't speak.

When the amount of liquefied gas decreases and the float is exposed by a certain amount, the float and the shaft descend, and the magnet also descends. When the influence of the magnet disappears due to the lowering of the magnet, the magnet switch is activated and the alarm means is activated.

In this way, the remaining amount of liquefied gas can be automatically notified.

Since this magnet switch is sealed inside the body, even if the liquefied gas is a flammable gas such as LPG or acetylene gas, the spark generated when the switch is turned on and off causes the vaporized liquefied gas to ignite. There is nothing to do.

〔Example〕

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

FIG. 1 and FIG. 2 show an embodiment of the remaining amount indicator of the liquefied gas container according to the present invention. The remaining amount sensor (20), which is the means for detecting the remaining amount of liquefied gas, has a substantially cylindrical main body (21) that can be attached to a liquefied gas container,
The upper half of the body (21) is a substantially hexagonal engaging portion (22) for engaging a spanner or the like, and the lower half is a screw portion (23) for screwing into the opening of the liquid container. Has been done.

A vacant chamber (23a) having a lower opening is provided inside the screw portion (23), and a connecting member, that is, a connecting nut (24) is screwed into the opening. As shown in FIG. 1, the connecting nut (24) is provided with a concave spherical surface portion (24a) and a taper portion (24b) so that the spherical portion (25a) of the tubular body, that is, the free sleeve (25) is concave spherical surface portion. It is held by slidingly contacting (24a). Therefore, the free sleeve (25) can swing about the spherical portion (25a).

(28) is a shaft, the upper end penetrates the center hole (25b) of the free sleeve (25) and reaches the empty chamber (23a) of the screw part (23), and the float (29) is fixed near the lower end. I am doing it. A magnet (31) is fixed to the upper end of the shaft (28), and as the shaft (28) moves up and down, the empty space (23
It is designed to move up and down in a). Shaft (2
Even if 8) is located at the lowest position, it will not come off from the free sleeve (25) by a locking body (not shown). In addition, the shaft (28) is formed thin so that the influence of buoyancy due to it is extremely small.

The shape of the float (29) is not a slender bar like the conventional liquid level gauge, but a light metal round bar that is much thicker than the shaft (28). An annular recess (30) for setting the liquid level at which the remaining amount detector (20) operates is formed in the approximate center of the float (29).

The shaft (28) is suspended by a reinforcing spring (26) whose upper end is fixed to the free sleeve (25) in order to reinforce the buoyancy of the float (29). Reinforcement springs (26)
The lower end of the shaft is fixed by a spring stopper (27) at a position above the shaft (28) where the liquefied gas is not immersed.

The shaft (28), the float (29), and the reinforcing spring (26) constitute a liquefied gas remaining amount sensing unit.

The engagement portion (22) of the main body (21) has an internal space (23
A space (22a) that is airtightly partitioned by a partition wall is provided, and a magnet switch (32) that is operated by the magnet (31) is provided in the space (22a). The upper opening of the empty room (22a) is the filling material (33)
The magnet switch (32) is sealed and protected in this way.

The lead wire (34) of the magnet switch (32) is connected to the alarm device (36) via the connector (35) outside the liquefied gas container, and the alarm device (36) is activated according to the operation of the magnet switch (32). An alarm is issued to notify that the predetermined remaining amount has been reached. Incidentally, (37) is a lead wire of the alarm device (36), and (38) is a power outlet.

A packing (50) is provided on the outer peripheral portion of the screw portion (23).

Next, the usage state of the remaining amount indicator having the above configuration will be described.

In FIGS. 3 (a) and 3 (b), (39) is a conventionally known liquefied gas container, which is composed of an outer tank (42) and an inner tank (43) and is located between both tanks (42) and (43). The space (44) is evacuated. Liquefied gas is stored in the inner tank (43). Reference numeral (40) is a lid that closes the opening of the liquefied gas container (39), and the main body (21) of the remaining amount sensor (20) is screwed and attached to a through hole provided in the center thereof, and the float ( 29) is immersed in the liquefied gas inside. The float (29) is located near the bottom of the inner tank (43). The packing (50) seals between the main body (21) and the lid (40). In addition, the reinforcement spring (2
6) is in a position where it is not immersed in liquefied gas.

The main body (21) of the remaining amount sensor (20) is divided by the main body (21) because the empty chamber (23a) communicating with the inner tank (43) and the empty chamber (22a) communicating with the outside are separated by a partition wall. Lids (40)
Through holes are sealed.

In addition, (45) is a pipe for supplying liquefied gas, (46) is a pipe for discharging gas, (47) and (48) are stop valves attached to both pipes (45) and (46), and (49) is It is a safety valve attached to the pipe (46).

As shown in Fig. 3 (a), when the liquefied gas is full, the float (29) has its own buoyancy and a reinforcing spring (2
It is pulled upward by the elastic force of 6) and is at the upper limit position,
The magnet (31) is in contact with the upper wall of the empty chamber (23a). In this state, the magnet switch (32) is off, so the alarm device (36) does not operate.

Even if liquefied gas is used and the liquid level (41) of the liquefied gas is lowered, the force that pushes up the shaft (28) hardly changes until a part of the float (29) is exposed from the liquefied gas. The switch (32) remains off. In this embodiment, the shaft (28) is made thinner than the float used in the conventional float type liquid level gauge, while the diameter of the float (29) is made larger than that of the shaft (28) so that the liquefied gas is The buoyancy is hardly changed by the change of the length of the shaft (28) immersed in the, and is largely changed by the exposure amount of the float (29) from the liquefied gas.

As the liquefied gas decreases, the liquid surface (4
When 1) drops below the annular recess (30), the float (2
9) The buoyancy is reduced and the force of pulling the float (29) downward is stronger than the force of pulling the reinforcing spring (26) upward.
The shaft (28) and the magnet (31) descend and reach the lower limit position. Then, the magnet switch (32) is switched to the ON state, and the alarm device (36) is activated to issue an alarm. In this way, it is possible to notify that the liquefied gas has reached the predetermined remaining amount.

Even when the liquefied gas container (39) is placed on a surface that is slightly inclined from the horizontal surface instead of a flat surface, the above operation is performed smoothly and no trouble occurs. In the present invention, the shaft (28) supporting the float (29) is attached to the free sleeve (25).
Since it is attached to the main body (21) via the, it can swing about the spherical portion (25a) of the free sleeve (25). Further, even if the liquefied gas container (39) swings during transportation, the shaft (28) swings following it, so that bending or twisting stress does not act on the shaft (28).

As the alarm device (36), a known device may be used as appropriate, but in order to increase the certainty of the notification, it is preferable to make a visual appeal with a lamp or the like and an auditory appeal with a buzzer or the like. .

〔The invention's effect〕

As is clear from the above description, the remaining amount indicator according to the present invention prevents the liquid level (41) of the liquefied gas from decreasing by the float (2
It can be detected by 9), and it can be automatically notified that a predetermined remaining amount has been reached by a switch composed of a magnet switch (32) and a magnet (31) and an alarm device (36).

Further, when the shaft (28) is swingably provided by the connecting nut (24) and the free sleeve (25), even if the liquefied gas container (39) is tilted, an unreasonable force does not act on the shaft (28), which is durable. Not only that, but it also has the advantage that the movement of the float (29) is not hindered, so that an alarm can be issued accurately.

In addition, since the magnet switch (32) is sealed inside the main body (21), even if it is a flammable gas such as liquefied gas or LPG or acetylene gas, the spark generated when the switch is turned on or off It does not catch fire and is safe.

Further, since the reinforcing spring (26) is not immersed in the liquefied gas and is not cooled to an ultralow temperature, there is an effect that the mechanical strength of the reinforcing spring (26) is small.

[Brief description of drawings]

1 to 3 show one embodiment of the remaining amount indicator of the present invention, and FIG. 1 is an explanatory view of the remaining amount detector, and FIG.
FIG. 3 is an explanatory view showing the overall structure, and FIG. 3 is a sectional explanatory view showing a state in which a remaining amount detector of a remaining amount indicator is attached to a liquefied gas container. FIG. 4 is a sectional explanatory view showing a conventional liquid level gauge. (20) …… Remaining amount sensor, (21) …… Main body, (22) …… Engagement part (22a) …… Vacancy, (23) …… Screw part, (23a) …… Vacancy (24 ) …… Connection nut, (24a) …… Concave spherical surface, (24
b) …… Tapered part (25) …… Free sleeve, (25a) …… Spherical part, (26)
…… Reinforcement spring (28) …… Shaft, (29) …… Float, (31) ……
Magnet (32) …… Magnet switch, (36) …… Alarm,
(39) …… Liquefied gas container

Claims (2)

(57) [Claims] 1. A main body mounted so as to seal the inside of a liquefied gas container, a shaft housed in the liquefied gas container and vertically movably mounted on the main body, and a magnet fixed to the upper end of the shaft. And a clogged metal float attached near the lower end of the shaft, and one end is fixed to the main body and the other end is fixed to a position above the shaft so as not to be immersed in the liquefied gas to assist the buoyancy of the float. A liquefied gas residual amount sensing means comprising a reinforcing spring and a magnet switch which is sealed in the main body and is turned on or off by approaching the magnet; and a magnetic switch of the liquefied gas residual amount sensing means, which is operated by a magnetic switch. And a warning means provided outside the liquefied gas container, wherein the float of the liquefied gas remaining amount sensing means is exposed to a certain amount from the liquefied gas. As a result, when the shaft descends and the influence of the magnet fixed to the upper end of the shaft disappears, the magnet switch is activated to activate the alarm means. Remaining amount indicator. 2. The remaining amount detecting means is slidable on a connecting member having a concave spherical surface portion fixed to an opening of a lower opening chamber in which a magnet provided in a main body moves up and down, and the concave spherical surface portion. Equipped with a cylindrical body having a spherical portion held by,
The remaining amount indicator of the liquefied gas container according to claim 1, wherein the shaft is attached to the cylindrical body so as to be vertically movable.