WO1999040553A1

WO1999040553A1 - Alarm device for sensing gas quantity within pressure vessel

Info

Publication number: WO1999040553A1
Application number: PCT/KR1999/000054
Authority: WO
Inventors: Wan Tae Kim; Sang Gu Bang; Byung Gul Lee
Original assignee: Wan Tae Kim; Sang Gu Bang; Byung Gul Lee
Priority date: 1998-02-05
Filing date: 1999-02-03
Publication date: 1999-08-12
Also published as: AU2188899A

Abstract

Disclosed is an alarm device for sensing an amount of gas within a pressure vessel (10) in which high pressure liquefied gas or liquid is charged such as, for example, an LPG tank used in general housings, a gas tank installed on LPG vehicles, a tank lorry for storing or carrying high pressure gas, a liquefied oxygen tank, a refrigerating pressure vessel and the like, to thereby inform a user that the pressure vessel (10) should be exchanged or recharged to be previously supplied with the shortage of the liquefied gas. The alarm device includes: a sensing unit (20) (a unit serving as a proximity switch, a photo-electric switch, an optical sensor, a magnetic sensor, an optical fiber, an oscillator and so on, or a unit being capable of performing other sensing operations) which is installed within a pressure vessel (10), for sensing an amount of gas stored in the pressure vessel (10); a transmission line (30) which is connected to the sensing unit (20), for transmitting a sensing result of the sensing unit (20); and an alarm unit (40) which is connected to the transmission line (30), for generating an alarm in response to an output signal of the transmission line (30).

Description

1 ALARM DEVICE FOR SENSING GAS QUANTITY WITHIN PRESSURE VESSEL

TECHNICAL FIELD

The present invention relates to an alarm device for sensing an amount of gas within a pressure vessel in which high pressure liquefied gas or liquid is charged such as, for example, a liquefied petroleum gas (hereinafter, referred to as "LPG") tank used in general housings, a gas tank installed on LPG vehicles, a tank lorry for storing or carrying high pressure gas, a liquefied oxygen tank, a refrigerating pressure vessel and the like, and more particularly, to an alarm device for sensing an amount of gas within pressure vessels which is capable of sensing an amount of liquefied gas within a pressure vessel in which an internal pressure exists therein to inform a user that the pressure vessel should be exchanged or recharged to be previously supplied with the shortage of the liquefied gas. Furthermore, the present invention relates to an alarm device for sensing an amount of gas within a pressure vessel which is capable of generating an alarm light or an alarm sound indicating a gas charging state during gas charging, to thereby charge a prescribed amount of liquefied gas to the pressure vessel. BACKGROUND ART

So as to store and delivery a large quantity of gas for the use of a fuel or other specific uses, high pressure is generally applied to the gas and thus the gas to which the high pressure has been applied is liquefied. As a result, the LPG or welding gas as a fuel generally used becomes in a liquid state, that is, liquefied gas state which is stored in the pressure vessel. However, in case of a small pressure vessel such as a general type of LPG tank or a high pressure oxygen tank, a user cannot previously sense a complete exhaustion of gas or a gas recharging time. Therefore, there frequently occurs a problem that the gas supply is abruptly stopped without warning, during consuming the gas.

On the other hand, in case of a gas tank installed on an LPG vehicle, since roughly 80% of a total amount of gas to be charged within the gas tank should be charged, there still remains a disadvantage in that an operator should continually check a gas charging state, while carefully monitoring a gauge attached on the gas tank.

To solve these problems, an effort that a spare pressure vessel is separately prepared is made, but it fails to suggest a complete solution thereto. In addition, a specific instrument board which adopts elasticity of a spring or a principle of a balance is 3 mounted on the pressure vessel, or the pressure vessel is made of a transparent synthetic resin. However, it accompanies some problems in that its structure is not simple or the instrument board is not accurate.

DISCLOSURE OF THE INVENTION

An object of the present invention is to provide an alarm device for readily sensing a residual amount of gas within a pressure vessel in which high pressure liquefied gas or liquid is charged such as, for example, an LPG tank used in general housings, a gas tank installed on LPG vehicles, a tank lorry for storing or carrying high pressure gas, a liquefied oxygen tank, a refrigerating pressure vessel and the like, to thereby inform a user that the pressure vessel should be exchanged or recharged to be previously supplied with the shortage of the liquefied gas. Another object of the present invention is to provide an alarm device for sensing an amount of gas within a pressure vessel which is capable of generating an alarm light or an alarm sound indicating a gas charging state during gas charging, to thereby charge a prescribed amount of liquefied gas to the pressure vessel.

To achieve these and other objects according to the present invention, there is provided an alarm device for sensing an amount of gas within a pressure vessel, which 4 includes: a sensing unit (a unit serving as a proximity switch, a photo-electric switch, an optical sensor, a magnetic sensor, an optical fiber, an oscillator and so on, or a unit being capable of performing other sensing operations) which is installed within a pressure vessel, for sensing an amount of gas stored in the pressure vessel; a transmission line which is connected to the sensing unit, for transmitting a sensing result of the sensing unit; and an alarm unit which is connected to the transmission line, for generating an alarm in response to an output signal of the transmission line.

BRIEF DESCRIPTION OF THE DRAWINGS

other objects and aspects of the invention will become apparent from the following description of embodiments with reference to the accompanying drawings in which:

FIG. 1 is a sectional view illustrating an alarm device for sensing gas quantity within a pressure vessel constructed according to a first embodiment of the present invention;

FIG. 2 is a sectional view illustrating a sensing unit in the alarm device according to the first embodiment of the present invention; FIG. 3 is a sectional view illustrating a differential pressure bush in the sensing unit of FIG. 2; 5 FIG. 4 is a circuit diagram illustrating an alarm unit in the alarm device according to the first embodiment of the present invention;

FIG. 5 is a sectional view illustrating an alarm device for sensing gas quantity within a pressure vessel constructed according to a second embodiment of the present invention;

FIG. 6 is a sectional view illustrating an alarm device for sensing gas quantity within a pressure vessel constructed according to a third embodiment of the present invention;

FIG. 7 is a sectional view illustrating an alarm device for sensing gas quantity within a pressure vessel constructed according to a fourth embodiment of the present invention; and

FIG. 8 is a sectional view illustrating an alarm device for sensing gas quantity within a pressure vessel constructed according to a fifth embodiment of the present invention.

BEST MODES FOR CARRYING OUT THE INVENTION

Hereinafter, an explanation on the construction and operation of an alarm device for sensing gas quantity within a pressure vessel constructed according to a first embodiment of the present invention will be in detail 6 discussed with reference to FIGS. 1 to 4.

As shown in FIG. 1, in an alarm device for sensing gas quantity within a pressure vessel constructed according to a first embodiment of the present invention, a sensing unit 20 is installed within a pressure vessel 10 in which high pressure liquefied gas or liquid is charged such as, for example, an LPG tank used in general housings, a gas tank installed on LPG vehicles, a tank lorry for storing or carrying high pressure gas, a liquefied oxygen tank, a refrigerating pressure vessel and the like. Sensing unit 20 serves to sense the current level of the liquefied gas remaining within pressure vessel 10 and sends the sensing result through a transmission line 30 to an alarm unit 40 which is installed within pressure vessel 10. As previously mentioned, sensing unit 20 is comprised of any one of a proximity switch, a photo-electric switch, an optical sensor, a magnetic sensor, an optical fiber, an oscillator and so on, or a means being capable of performing other sensing operations. In other words, sensing unit 20 may be comprised of various kinds of means in accordance with a pressure vessel type or a content characteristic within the pressure vessel, which is not limited to any specific means in the preferred embodiments of the present invention. In the first embodiment of the present invention, sensing unit 20 is comprised of the optical fiber. In 7 construction, as shown in FIG. 2, if the liquid level of the liquefied gas within pressure vessel 10 reaches a level 'Y' as the liquefied gas is consumed, a through hole h on an operator 21 which is descended along with a buoyant body 22 over the liquid level is shielded by the operation of a sensor 23. The shielding of through hole h by sensor 23 is sent via transmission line 30 made of the optical fiber to alarm unit 40, such that a user can recognize a residual amount of the liquefied gas. In the first embodiment of the present invention, the residual amount of the liquefied gas can be sensed by the ascending/descending operations of operator 21 over the liquid level thereof within sensing unit 20, but may be sensed by the same operation of sensor 23. Also, the bottom surface of pressure vessel 10 may be utilized as operator 21 in accordance with the characteristic of sensor 23.

As shown in FIG. 3, transmission line 30 includes a differential pressure bush 52 which contains a differential pressure packing 50 and a fixing supporting member 51, for preventing leakage of gas or disconnection of line in the connected portion of pressure vessel 10 with the exterior thereof. Otherwise, transmission line 30 may be used to be directly engaged with an existing vessel or a valve. On the other hand, only a jointed portion of differential pressure bush 52 and transmission line 30 is made of a glass fiber or both of them can be made of the glass fiber. A general gas leakage prevention law is applied in accordance with a type, a sensing position, or a characteristic of sensor 23. At the time, it is preferable that a cap 53 as shown in FIG. 1 is installed on the lower portion of fixed supporting member 51, for preventing sensing unit 20 and transmission line 30 from being damaged during the gas charging. In other words, an installation aim of cap 53 is to prevent the pressure generated from the liquefied gas during the gas charging from being directly applied to sensing unit 20 and transmission line 30.

Moreover, alarm unit 40 serves to indicate graduation or generate an alarm light or sound to thereby inform a user of a residual amount of the liquefied gas within pressure vessel 10, an exchange time of the corresponding pressure vessel 10, or a gas recharging time of the liquefied gas therein. For instance, predetermined lines A, B and C, as shown in FIG. 6, are defined to indicate the residual amount of the liquefied gas within pressure vessel 10. That is, line A indicates a full charging state of the liquefied gas, line B indicates a consumable time of the liquefied gas for 3 hours under the maximum heat power, and line C indicates a consumable time of the liquefied gas for 1 hours under the 9 maximum heat power. In this case, differential alarm sounds are generated at lines B and C in order for a user to correctly recognize the consuming states of the liquefied gas. At the time, a flow gauge indicating a residual amount of the liquefied gas within pressure vessel 10 is of course installed within alarm unit 40.

FIG. 4 is a circuit diagram illustrating alarm unit 40 in the alarm device according to the first embodiment of the present invention. A reference numeral 41 represent a switch of alarm unit 40, a reference numeral 42 a speaker for generating an alarm sound, and a reference numeral 43 an alarm light contained in alarm unit 40.

In another embodiment of the present invention, sensing unit 20 is separately installed on the top portion of the inner side of pressure vessel 10, and if a prescribed amount of liquefied gas is charged, alarm light 43 in alarm unit 40 is turned on and simultaneously the alarm sound is generated from speaker 42.

In FIG. 5 showing an alarm device constructed according to a second embodiment of the present invention, meanwhile, a pressure sensor 60 is installed within pressure vessel 10, for generating a radio wave in accordance with a sensing result thereof, and alarm unit 40 receives the radio wave generated from pressure sensor 60 to turn on the alarm light 10 and at the same time generate the alarm sound.

Pressure sensor 60 serves as a radio transmitter, and alarm unit 40 serves as a radio receiver. At the time, pressure sensor 60 functions as a buoyant body on the liquid level of the liquefied gas within pressure vessel 10 to thereby sense a residual amount of the corresponding liquefied gas.

Since the alarm device according to the second embodiment of the present invention does not install transmission line 30 which connects sensing unit 20 and alarm unit 40 in the first embodiment, it can obtain saving effects of production cost.

In FIG. 6 showing an alarm device constructed according to a third embodiment of the present invention, a sensing unit including two or more sensors 20 can be installed within pressure vessel 10. The construction where two or more sensors 20 are installed is useful in a pressure vessel (for example, a large size of vessel such as a storage tank, a tank lorry, and a ball tank) where a residual amount of liquefied gas should be frequently checked.

In case of the LPG tank installed in a laid-down state on the vehicle, as shown in FIG. 7 illustrating a fourth embodiment of the present invention, three or more sensing units 20 are arranged in a width direction. A line D 11 indicates a line for warning a smallest amount of liquefied gas, a line E indicates a normally charged level of the liquefied gas, and a line F indicates a regulated line for charging the liquefied gas. In more detail, line D is defined when the amount of the liquefied gas charged within pressure vessel 10 is exhausted and should be recharged, and line E is defined when approximately 80% of the maximum charging amount of the liquefied gas is charged. If the gas charging exceeds line E, there occurs a problem that the gas tank itself is under an unstable state. Accordingly, since sensing unit 20 is mounted on the corresponding portions to lines D, E and F, respectively, it can accurately sense the liquid level of the liquefied gas which passes through the corresponding line and send the sensing result via transmission line 30 to alarm unit 40.

FIG. 8 is a sectional view illustrating an alarm device for sensing gas quantity within a pressure vessel constructed according to a fifth embodiment of the present invention. In construction, a thin bar 71 which mounts a buoyant body 72 on the one end thereof and a permanent magnet 73 on the other end thereof is performed as a sensing unit. A thin display plate 74, which is made of a nonmagnetic material is mounted on a portion in the vicinity of 12 permanent magnet 73, and a tracer 75, which is comprised of a small permanent magnet, is installed on the opposite side of permanent magnet 73. If buoyant body 72 is moved upwardly and downwardly on the liquid level of the liquefied gas, permanent magnet 73 and tracer 75 are moved along with buoyant body 72. At the time, in case of indicating graduation on display plate 74, the residual amount of the liquefied gas within pressure vessel 10 can be accurately sensed. Moreover, display plate 74 is surrounded with a vinyl tape (not shown) , and tracer 75 attaches to the tape surface on permanent magnet 73. In this case, if the graduation is indicated on the outer surface of the tape, the graduation is descended as buoyant body 72 is descended along the liquid level of the liquefied gas. In other words, as the liquefied gas within pressure vessel 10 is consumed, the graduation indicative of the residual amount of the liquefied gas is also descended.

On the other hand, tracer 75 is moved for sensing the residual amount of the liquefied gas in the preferred embodiment of the present invention, but all of buoyant body 72, permanent magnet 73 and tracer 75 may function as the sensing unit which is connected to the transmission line (not shown) to send the sensing result to the alarm unit or 13 a level display.

A sensing means for sensing the movement of tracer 75 is comprised of magnetic sensing reed switches which are arranged in a predetermined interval to be recognized in a resistance type by grades, or a composite switch which operates by a magnetic force in accordance with the position of tracer 75. Furthermore, an additional sensing means which is comprised of an optical fiber may be contained. At the time, the corresponding sensing means should be engaged with the permanent magnet, tracer 75.

In a method of transmitting the movement of buoyant body 72, buoyant body 72 is connected by a wire and the movement thereof is changed to a straight line type manner or a rotational force type manner, or to various gear types manner in a conventional technical fashion. In case of a small buoyant body, it can be shaped by utilizing a principle of a pulley set.

As well appreciated, the alarm device constructed according to the preferred embodiment of the present invention can sense and inform the residual amount of the liquefied gas within the pressure vessel.

INDUSTRIAL APPLICABILITY 14 As discussed in the above, an alarm device according to the preferred embodiments of the present invention can sense an amount of liquefied gas within a pressure vessel in which high pressure liquefied gas or liquid is charged such as, for example, an LPG tank used in general housings, a gas tank installed on LPG vehicles, a tank lorry for storing or carrying high pressure gas, a liquefied oxygen tank, a refrigerating pressure vessel and the like, to thereby inform a user that the pressure vessel should be exchanged or recharged to be previously supplied with the shortage of the liquefied gas. In addition, an alarm device constructed according to the preferred embodiments of the present invention can supply only a prescribed amount of liquefied gas to the pressure vessel, to previously prevent generation of problems related to stability caused due to an overcharging.

Although a preferred form of the invention has been described, it will be understood by those skilled in the field that variations therefrom, and analogous uses, are within the knowledge of those skilled in the art.

Accordingly, it is intended that the scope of the invention be defined, not by the scope of the foregoing description, but rather by the scope of the claims as interpreted in view of the pertinent prior art.

Claims

15 CLAIMS

1. An alarm device for sensing an amount of liquefied gas within a pressure vessel, said device comprising: a sensing unit installed within said pressure vessel, for sensing an amount of the liquefied gas stored in said pressure vessel; a transmission line connected to said sensing unit, for transmitting a sensing result of said sensing unit; and an alarm unit connected to said transmission line, for generating an alarm in response to an output signal of said transmission line.

2. The alarm device as claimed in claim 1, wherein said sensing unit is comprised of: a buoyant body installed on a liquid level of the liquefied gas within said pressure vessel; an operator descended along the liquid level of the liquefied gas, together with said buoyant body; and a sensor for shielding a through hole on said operator which is descended to a predetermined position.

3. The alarm device as claimed in claim 1, wherein said transmission line is comprised of an optical fiber. 16

4. The alarm device as claimed in claim 1, wherein said sensing unit is additionally installed on a top portion of the inner side of said pressure vessel, for sensing whether a prescribed amount of the liquefied gas is charged.

5. An alarm device for sensing an amount of liquefied gas within a pressure vessel, said device comprising: a pressure sensor installed in the interior of said pressure vessel, for sensing a residual amount of the liquefied gas to generate a radio wave in accordance with a sensing result thereof; and an alarm unit for receiving the radio wave generated from said pressure sensor to generate an alarm sound.

6. An alarm device for sensing an amount of liquefied gas within a pressure vessel, said device comprising: a buoyant body installed on a liquid level of the liquefied gas within said pressure vessel; a transmitting unit for transmitting movement of said buoyant body to a front end of a transmitting axis by using a mechanical transmission method; a sensing unit comprised of an optical fiber, for sensing change on the front end of the transmitting axis; and 17 an alarm unit for generating an alarm in accordance with an output signal of said sensing unit.

7. The alarm device as claimed in claim 6, wherein said sensing unit is a plurality of switches which are operated by a magnetic force.

8. The alarm device as claimed in claim 6, wherein said sensing unit is comprised of a bar which installs said buoyant body on the one end thereof and a permanent magnet on the other end thereof; a display plate of a non-magnetic material which is installed on said permanent magnet; and a tape attached on said permanent magnet to surround said display plate.

9. The alarm device as claimed in claim 6, wherein said sensing unit is comprised of magnetic sensing reed switches which are arranged in a predetermined interval to be recognized in a resistance type by grades.