GB1604410A - Flameproofing and inerting systems - Google Patents

Flameproofing and inerting systems Download PDF

Info

Publication number
GB1604410A
GB1604410A GB52046/77A GB5204677A GB1604410A GB 1604410 A GB1604410 A GB 1604410A GB 52046/77 A GB52046/77 A GB 52046/77A GB 5204677 A GB5204677 A GB 5204677A GB 1604410 A GB1604410 A GB 1604410A
Authority
GB
United Kingdom
Prior art keywords
motor
sensor
equipment
actuator
flammable
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB52046/77A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Pyroban Ltd
Original Assignee
Pyroban Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Pyroban Ltd filed Critical Pyroban Ltd
Priority to GB52046/77A priority Critical patent/GB1604410A/en
Priority to ZA786928A priority patent/ZA786928B/en
Priority to DE19782854025 priority patent/DE2854025A1/en
Priority to JP15377278A priority patent/JPS5496751A/en
Publication of GB1604410A publication Critical patent/GB1604410A/en
Expired legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02HEMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H5/00Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal non-electric working conditions with or without subsequent reconnection
    • EFIXED CONSTRUCTIONS
    • E21EARTH OR ROCK DRILLING; MINING
    • E21FSAFETY DEVICES, TRANSPORT, FILLING-UP, RESCUE, VENTILATION, OR DRAINING IN OR OF MINES OR TUNNELS
    • E21F17/00Methods or devices for use in mines or tunnels, not covered elsewhere
    • E21F17/18Special adaptations of signalling or alarm devices
    • EFIXED CONSTRUCTIONS
    • E21EARTH OR ROCK DRILLING; MINING
    • E21FSAFETY DEVICES, TRANSPORT, FILLING-UP, RESCUE, VENTILATION, OR DRAINING IN OR OF MINES OR TUNNELS
    • E21F9/00Devices preventing sparking of machines or apparatus

Landscapes

  • Engineering & Computer Science (AREA)
  • Mining & Mineral Resources (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Geology (AREA)
  • Fire-Extinguishing By Fire Departments, And Fire-Extinguishing Equipment And Control Thereof (AREA)
  • Safety Devices In Control Systems (AREA)
  • Switch Cases, Indication, And Locking (AREA)

Description

(54) FLAMEPROOFING AND INERTING SYSTEMS (71) We, PYROBAN LIMITED, a Com- pany registered under the laws of England, of Endeavour Works, Dolphin Road, Shoreham by-Sea, Sussex BN4 6PB (formerly of Endeavour Works, Star Road, Estate, Partridge Green, Horsham, Sussex RH13 8QS) do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to the flameproofing of electrical equipment in order to make the equipment safe for use in hazardous locations.
Electrical equipment used for a variety of purposes on or in, for example, oil rigs, mines or other places where flammable materials may be present can entail a risk of ignition of the materials, or their vapours as a result of sparking.
These materials will frequently be hydrocarbons, but may be any material which is capable of spark igintion or explosion.
For the purposes of the present invention any location where such a risk may occur is to be regarded as a hazardous location.
According to the present invention, a shut-down system for electrical equipment for use in hazardous locations comprises a sensor for detecting the presence of a flammable mixture in the vicinity of the equipment, and means operable responsive to signals from the sensor to shut down the equipment, the said shut-down means comprising control means, a low voltage power pack (i.e. of a voltage and capacity insufficient to cause spark ignition of the said mixture) and an actuator disposed to operate an isolation switch between the equipment and its power source, the control means being programmed to operate the isolation switch by discharge from the power pack to the actuator on receipt of signals from the sensor.
The control means may be programmed to operate the isolation switch on receipt of signals from the sensor indicative of a threshold level of a concentration in air of flammable mixture at a low percentage, e.g. 20 %, of the lower explosive limit of that mixture.
It will be appreciated that for a given hazarddous location the nature of the flammable mixture which is likely to be encountered will be known thus enabling the control means to be set to respond at an appropriate point.
It has previously been necessary to flameproof electrical equipment intended for use in hazardous locations by encapsulation of the equipment, thus reducing to as low a level as possible contact of the atmosphere in the vicinity of the equipment with surfaces of the equipment at which a risk of arcing may be present. The encapsulation can also contain any ignition or explosion which might nonethe less occur. such techniques are costly and frequently involve unacceptable increases both in the bulk of the equipment and in its cost.
With the system of the present invention the electrical equipment is installed and operated as it would be for operation in a nonhazardous location, except in so far as modification is necessary to incorporate the shut down system of the invention, and the equipment is operated normally as long as the atmosphere in the vicinity of the equipment remains normal, i.e. non-hazardous. However as soon as a threshold concentration of a flammable mixture is detected by the sensor at some low proportion of the lower explosive limit, the equipment will be shut down so that no further risk of sparking is involved, and before the environment has reached hazardous proportions.
The system may further be provided with a source of non-flammable fluid and further means operable responsive to signals from the sensor to release the fluid from the source into the vicinity of the equipment, for example into the equipment compartment or into a space between the equipment and a canopy shrouding the equipment. The fluid may be released simultaneously to more than one item of equipment and may be an inert gas e.g.
carbon-dioxide or a halogenated gas snch is available in the United Kingdom under the trade name "Halon".
The control means, in addition to being programmed to operate the isolation switch, may also be programmed to operate the fluid release means at the same, or a different threshold concentration of a flammable mixture.
The actuator may be an electrically fired explosive linear actuator device such as that available in the United Kingdom under the trade name "Metron" or a solenoid. Such an actuator may also be used to release the fluid from the source.
In one form of the invention a battery powered vehicle or installation is provided with a shut-down system as defined above, the shut-down means operating to isolate the motor of the vehicle or installation from its batteries on detection by the sensor of a predetermined threshold concentration of a flammable mixture. The isolation of the motor from its batteries may be accompanied by injection of inert gas into the battery and motor compartments.
In another form of the invention, an externally powered motor driven electrical vehicle or installation is provided with an inerting system as defined above, the shutdown means operating to isolate the motor of the vehicle or installation from its power supply on detection by the sensor of a predetermined threshold concentration of a flammable mixture. The isolation of the motor from its power supply may be accompaied by an injection of inert gas into the motor compartment.
The invention may be performed in many ways and some specific embodiments will now be described, by way of example with reference to the accompanying diagrammatic drawings in which: Figure 1 shows an assembly embodying the invention and Figure 2 shows a further assembly embodying the invention, Referring to the drawings, a piece of electrical equipment 12, such as an electric motor, is connected to a source of electrical power 10, such as a battery bank or a mains supply through an isolation switch 11. The isolation switch 11 is spring loaded towards an open position but is held closed against the spring by a cam and latch mechanism when the electrical equipment 12 is in operation.
A gas sensor 15 is located in the vicinity of the electrical equipment 12 and when it detects the presence of flammable material in the air it sends a signal to electronic control means 20.
The control means 20 contains a low voltage, intrinsically safe, Nickel/Cadmium, power pack and is programmed to operate the isolation switch 11 by discharge from the power pack to an actuator 22 on receipt of signals from the sensor 15 indicative of a predetermined threshold level of flammable material in the air.
The actuator 22 is a "Metron" actuator disposed to trip the cam and latch mechanism when fired by the discharge from the power pack within the control means 20 and thereby to allow the isolation switch 11 to open with its spring bias, thus isolating the electrical equipment 12 from its power supply 10.
When the assembly is to be used in hazardous locations where hydrocarbons and other normal industrial flammable gases are likely to be the main source of danger, a suitable predetermined level of flammable mixture in the air may be 20% V/V of the lower explosive limit of the material so that the electrical equipment 12 is shut-down and therefore safe with regard to possible ignition of the flammable material well before any significant danger of ignition is present. Until the sensor indicates such a level the electrical equipment 12 is allowed to operate normally and in the absence of conventional flameproofing attachments and precautions.
Figure 2 shows a system substantially as described in relation to Figure 1 except in that the control means 20 is further programmed to fire a "Metron" actuator 23 disposed at the head of a cylinder 25 containing "Halon" inert gas under pressure. Firing the actuator 23 will rupture a seal (not shown) in the head of the cylinder 25 and allow the gas to escape along the conduits 30 and 31 leading to the power supply 10 and electrical equpment 12 respectively. The gas, when it reaches the electrical equipment 12 will render the atmosphere around those items inert to safeguard against ignition of the flammable material detected.
The control means may be programmed to operate "Metron" actuators 22 and 23 simultaneously or one before the other depending on the particular operational requirements.
In further embodiments the functions of the "Metron" actuators could be performed by other solenoid and mechanical linkages.
WHAT WE CLAIM IS: 1. A shut down system for electrical equipment for use in hazardous locations (as herein defined) comprising a sensor for detecting the presence of flammable mixture in the vicinity of the equipment, and shutdown means operable responsive to signals from the sensor to shut down the equipment, the said shut-down means comprising control means, a low voltage power pack, and an actuator disposed to operate an isolation switch between the equipment and its power source, the control means being programmed to operate the isolation switch by discharge from the power pack to the actuator on receipt of signals from the sensor.
2. A system as claimed in Claim 1 wherein the shutdown means operates responsive
**WARNING** end of DESC field may overlap start of CLMS **.

Claims (18)

**WARNING** start of CLMS field may overlap end of DESC **. The control means, in addition to being programmed to operate the isolation switch, may also be programmed to operate the fluid release means at the same, or a different threshold concentration of a flammable mixture. The actuator may be an electrically fired explosive linear actuator device such as that available in the United Kingdom under the trade name "Metron" or a solenoid. Such an actuator may also be used to release the fluid from the source. In one form of the invention a battery powered vehicle or installation is provided with a shut-down system as defined above, the shut-down means operating to isolate the motor of the vehicle or installation from its batteries on detection by the sensor of a predetermined threshold concentration of a flammable mixture. The isolation of the motor from its batteries may be accompanied by injection of inert gas into the battery and motor compartments. In another form of the invention, an externally powered motor driven electrical vehicle or installation is provided with an inerting system as defined above, the shutdown means operating to isolate the motor of the vehicle or installation from its power supply on detection by the sensor of a predetermined threshold concentration of a flammable mixture. The isolation of the motor from its power supply may be accompaied by an injection of inert gas into the motor compartment. The invention may be performed in many ways and some specific embodiments will now be described, by way of example with reference to the accompanying diagrammatic drawings in which: Figure 1 shows an assembly embodying the invention and Figure 2 shows a further assembly embodying the invention, Referring to the drawings, a piece of electrical equipment 12, such as an electric motor, is connected to a source of electrical power 10, such as a battery bank or a mains supply through an isolation switch 11. The isolation switch 11 is spring loaded towards an open position but is held closed against the spring by a cam and latch mechanism when the electrical equipment 12 is in operation. A gas sensor 15 is located in the vicinity of the electrical equipment 12 and when it detects the presence of flammable material in the air it sends a signal to electronic control means 20. The control means 20 contains a low voltage, intrinsically safe, Nickel/Cadmium, power pack and is programmed to operate the isolation switch 11 by discharge from the power pack to an actuator 22 on receipt of signals from the sensor 15 indicative of a predetermined threshold level of flammable material in the air. The actuator 22 is a "Metron" actuator disposed to trip the cam and latch mechanism when fired by the discharge from the power pack within the control means 20 and thereby to allow the isolation switch 11 to open with its spring bias, thus isolating the electrical equipment 12 from its power supply 10. When the assembly is to be used in hazardous locations where hydrocarbons and other normal industrial flammable gases are likely to be the main source of danger, a suitable predetermined level of flammable mixture in the air may be 20% V/V of the lower explosive limit of the material so that the electrical equipment 12 is shut-down and therefore safe with regard to possible ignition of the flammable material well before any significant danger of ignition is present. Until the sensor indicates such a level the electrical equipment 12 is allowed to operate normally and in the absence of conventional flameproofing attachments and precautions. Figure 2 shows a system substantially as described in relation to Figure 1 except in that the control means 20 is further programmed to fire a "Metron" actuator 23 disposed at the head of a cylinder 25 containing "Halon" inert gas under pressure. Firing the actuator 23 will rupture a seal (not shown) in the head of the cylinder 25 and allow the gas to escape along the conduits 30 and 31 leading to the power supply 10 and electrical equpment 12 respectively. The gas, when it reaches the electrical equipment 12 will render the atmosphere around those items inert to safeguard against ignition of the flammable material detected. The control means may be programmed to operate "Metron" actuators 22 and 23 simultaneously or one before the other depending on the particular operational requirements. In further embodiments the functions of the "Metron" actuators could be performed by other solenoid and mechanical linkages. WHAT WE CLAIM IS:
1. A shut down system for electrical equipment for use in hazardous locations (as herein defined) comprising a sensor for detecting the presence of flammable mixture in the vicinity of the equipment, and shutdown means operable responsive to signals from the sensor to shut down the equipment, the said shut-down means comprising control means, a low voltage power pack, and an actuator disposed to operate an isolation switch between the equipment and its power source, the control means being programmed to operate the isolation switch by discharge from the power pack to the actuator on receipt of signals from the sensor.
2. A system as claimed in Claim 1 wherein the shutdown means operates responsive
to signals from the sensor indicative of a flammable gas concentration of 20% of the lower explosive limit of the said gas.
3. A system as claimed in any of the preceding Claims having a source of nonflammable fluid and having further means operable responsive to signals from the sensor to release the fluid from the source in the vicinity of the equipment.
4. A system as claimed in Claim 3 in which the fluid is injected into the equipment compartment.
5. A system as claimed in Claim 3 in which the fluid is injected into the space between the equipment and a canopy shrouding the equipment.
6. A system as claimed in any of Claims 3 to 5 in which the fluid is released simultaneously to more than one item of equipment.
7. A system as claimed in any of Claims 3 to 6 wherein the fluid is an inert gas.
8. A system as claimed in any of Claims 3 to 7 wherein the fluid release means operates responsive to signals from the sensor indicative of a flammable gas concentration of 20 % of the lower explosive limit of the said gas.
9. A system as claimed in any of the preceding Claims in which the actuator is an electrically fired linear explosive device.
10. A system as claimed in any of Claims 1 to 8 in which the actuator is a solenoid.
11. A system as claimed in any of Claims 3 to 10 wherein the fluid release means comprises an electrically fired linear explosive device.
12. A system as claimed in any of Claims 3 to 10 wherein the fluid release means comprises a solenoid.
13. A shut down system for electrical equipment for use in hazardous locations (as herein defined) substantially as described herein with reference to the accompanying drawings.
14. A battery powered electrical vehicle or installation having a motor and shut down system as claimed in any of Claims 1 to 13 in which on detection by the sensor of a predetermined level of flammable vapour, the shut-down means isolate the motor from the batteries.
15. A vehicle or installation as claimed in Claim 14 in which isolation of the motor from its batteries is accompanied by injection of inert gas into the battery and/or motor compartments.
16. An externally powered motor driven electrical vehicle or installation having a motor and a shut-down system as claimed in any of Claims 1 to 13 in which on detection by the sensor of a predetermined level of flammable vapour, the shut-down means isolate the motor from its power supply.
17. A vehicle or installation as claimed in.
Claim 16 in which isolation of the motor from its power supply is accompanied by injection of inert gas into the motor compartment.
18. An electrical vehicle or installation substantially as described herein with reference to the accompanying drawings.
GB52046/77A 1977-12-14 1977-12-14 Flameproofing and inerting systems Expired GB1604410A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
GB52046/77A GB1604410A (en) 1977-12-14 1977-12-14 Flameproofing and inerting systems
ZA786928A ZA786928B (en) 1977-12-14 1978-12-11 Flameproofing and inerting system
DE19782854025 DE2854025A1 (en) 1977-12-14 1978-12-14 EXPLOSION PROTECTION DEVICE FOR ELECTRICAL SYSTEMS
JP15377278A JPS5496751A (en) 1977-12-14 1978-12-14 Breaking unit for electric equipment

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB52046/77A GB1604410A (en) 1977-12-14 1977-12-14 Flameproofing and inerting systems

Publications (1)

Publication Number Publication Date
GB1604410A true GB1604410A (en) 1981-12-09

Family

ID=10462442

Family Applications (1)

Application Number Title Priority Date Filing Date
GB52046/77A Expired GB1604410A (en) 1977-12-14 1977-12-14 Flameproofing and inerting systems

Country Status (4)

Country Link
JP (1) JPS5496751A (en)
DE (1) DE2854025A1 (en)
GB (1) GB1604410A (en)
ZA (1) ZA786928B (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2149658A (en) * 1983-11-18 1985-06-19 Barcrest Ltd Fire extinguishing systems
GB2205037A (en) * 1987-04-24 1988-11-30 Faini Spa Fire-extenguishing device for electrical equipment having flammable components
GB2217200A (en) * 1988-04-08 1989-10-25 Pyroban Limited Explosion protection system
GB2378559A (en) * 2001-07-03 2003-02-12 Lerwick Engineering & Fabricat Gas detection and the automatic shut down of apparatus
WO2012110965A1 (en) * 2011-02-16 2012-08-23 Ansaldo Sistemi Industriali S.P.A. Device for analysing the internal atmosphere of the casing of an electric rotating machine
WO2013132179A1 (en) * 2012-03-06 2013-09-12 Renault S.A.S. Rapid cooling device for a motor vehicle comprising a component fitted with a diffuser

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2126025B (en) * 1982-08-14 1986-01-15 Dresser Europe Sa Power supply system and mining machine incorporating such system
DE3271481D1 (en) * 1982-12-28 1986-07-03 Bernhard Schneider Clearing plate for a shearer drum

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2149658A (en) * 1983-11-18 1985-06-19 Barcrest Ltd Fire extinguishing systems
GB2205037A (en) * 1987-04-24 1988-11-30 Faini Spa Fire-extenguishing device for electrical equipment having flammable components
GB2217200A (en) * 1988-04-08 1989-10-25 Pyroban Limited Explosion protection system
GB2378559A (en) * 2001-07-03 2003-02-12 Lerwick Engineering & Fabricat Gas detection and the automatic shut down of apparatus
WO2012110965A1 (en) * 2011-02-16 2012-08-23 Ansaldo Sistemi Industriali S.P.A. Device for analysing the internal atmosphere of the casing of an electric rotating machine
US9366660B2 (en) 2011-02-16 2016-06-14 Nidec Asi S.P.A. Device for analyzing the internal atmosphere of the casing of an electronic rotating machine
WO2013132179A1 (en) * 2012-03-06 2013-09-12 Renault S.A.S. Rapid cooling device for a motor vehicle comprising a component fitted with a diffuser
FR2987871A1 (en) * 2012-03-06 2013-09-13 Renault Sa QUICK COOLING DEVICE FOR MOTOR VEHICLE COMPRISING A PIECE WITH A DIFFUSER
CN104159790A (en) * 2012-03-06 2014-11-19 雷诺股份公司 Rapid cooling device for a motor vehicle comprising a component fitted with a diffuser
US9482141B2 (en) 2012-03-06 2016-11-01 Renault S.A.S. Rapid cooling device for a motor vehicle comprising a component fitted with a diffuser

Also Published As

Publication number Publication date
JPS5496751A (en) 1979-07-31
DE2854025A1 (en) 1979-07-19
ZA786928B (en) 1980-07-30

Similar Documents

Publication Publication Date Title
US9259601B2 (en) Release device
US3789231A (en) Vapor detector safety system
GB1604410A (en) Flameproofing and inerting systems
WO2020114536A3 (en) Protection system for a hazardous load, in particular for electric vehicles which are defective or are involved in an accident, container for said load and method for protecting same
EP0988227A1 (en) Method to prevent explosions in aircraft fuel tanks
CN106659919A (en) Suppression and isolation system
EP3329970B1 (en) Safety system for fire suppressant distribution devices
US3023576A (en) Safety system for explosive actuated devices
JP2019509202A (en) Compressed natural gas vehicle safety system and method
US3335323A (en) Electrical apparatus and machines for protection against fire and explosion hazards
US6269746B1 (en) Disarm mechanism for explosive equipment
US4125886A (en) Protective installation
CN2613711Y (en) Automatic combustible gas alarm and exhausting apparatus
RU2557726C2 (en) Method and device for two-stage system to combat hazard
US6360526B2 (en) Rocket motor with desensitizer injector
Vishwakarma et al. Safety aspects, selection and use of equipment for material handling in mining and process industries: from conveying to cranes
Vishwakarma et al. Development of dust ignition protected electrically powered forklift truck for combustible dust environment
WO2011021967A1 (en) Device for preventing vehicle fires and explosions
US3817180A (en) Mine fuzes
EP0799077B1 (en) A safety system for a materials handling device
JP2009030529A (en) Safety device
WO2022130321A1 (en) Vehicle battery safety system
KR20240082527A (en) Fire Detection and Fire Extinguishing Devices for Vehicles
SU1710443A2 (en) Control device of explosion protection system of electrical equipment
KR200265863Y1 (en) a case of explosion prevention

Legal Events

Date Code Title Description
PS Patent sealed
PCNP Patent ceased through non-payment of renewal fee