IL45024A

IL45024A - Fire detection and extinguishing system

Info

Publication number: IL45024A
Application number: IL45024A
Authority: IL
Original assignee: Pyrotector Inc
Priority date: 1973-07-19
Filing date: 1974-06-12
Publication date: 1977-04-29
Also published as: AR202937A1; FR2237650A1; US3865192A; AU7018974A; IT1019711B; IL45024A0; DE2430100A1; FR2237650B1; JPS5088887A; JPS5423518B2; ZA744506B; NL7409711A; BR7405959A; GB1455755A; CA1009338A; CH571869A5

Abstract

A fire extinguishing system in which an optical flame detector, on seeing radiation from a fire, causes energization of a solenoid valve to release an extinguishant. Means responsive to the pressure created by the released extinguishant creates an additional circuit to the solenoid to lock it in the energized condition. Manual means is provided for operating the valve, in which case the pressure responsive means energizes the solenoid to insure continuous and complete discharge of the extinguishant. Timing means is also provided to open the solenoid after a predetermined time. [US3865192A]

Description

detection and system A fire extinguishing system in which an optical flame on seeing radiation from a causes energization of a solenoid to release an Means responsive to the pressure created by released extinguishant creates an additional circuit to the solenoid to lock it in the energized Manual means is provided for operating the in which case the pressure responsive means energizes the solenoid to insure continuous and complete discharge of the Timing means is also provided to open the solenoid after a predetermined OP The object of the invention is to provide a fire detection and extinguishing system which is particularly adapted for use on boats of the small pleasure craft which is fast enough in operation to extinguish burning before there is an substantial damage to the As is well gasoline fumes often collect in the bilges and engine compartment of such and when a spark such from a starter relay or from generator or starter an explosion can With the advent of new types of extinguishan and with the availability of a new type of solenoid disclosed in Israel Patent Specification it has become possible to provide an optically actuated extinguishing system which is fast enough in operation to suppress explosions of the type that occur in such vessels as a result of ignition of gasoline Although explosion suppression systems are known and which means that the explosion must be well started before the system is called into Hence the use of a squib operated valve is required to obtain the necessary speed of valve Although such valves are fast in they have serious The squib used to actuate such valves is explosive and is sensitive to stray currents such as are generated by radio frequency signals from a transmitter on the the valve operated by the squib must be disassembled after firing to the sealing diaphragm ruptured by the and pieces of the diaphragm can jam in the discharge piping or at a SUMMARY OF THE INVENTION The fire detection and explosion suppression system disclosed utilizes an optical detection device viewing the space to be device being responsive to radiation from a fire to provide a signal to an said amplifier actuating circuitry to energize a relay to actuate a solenoid valve of the type disclosed in the above mentioned The downstream pressure created by the released extinguishant operates a pressure responsive switch which locks in the circuit to the solenoid so that in case of temporary loss of signal by the optical the extinguishant will continue to The solenoid is energized from a voltage source greater than the designed voltage of the solenoid coil to insure rapid operation of the and timing means is provided in the solenoid circuit to the solenoid after a predetermined interval to avoid excessive heating of the solenoid BRIEF DESCRIPTION OF THE DRAWING Figure 1 is a schematic of an extinguishing system embodying the features of the Figure 2 is a schematic diagram of one form of electric circuit that may be used to control the operation of the system of Figure DESCRIPTION OF THE ILLUSTRATED EMBODIMENT Referring to Figure there is illustrated a fire detector and jxplosion suppression which comprises generally one or more optical Jetection units 10 for supplying a signal to an amplifier 12 to energize the solenoid 14 of a solenoid actuated valve to release extinguishant from a 18 and distribute it through suitable piping 20 to discharge nozzles to the space viewed by the optical detection A pressure switch 24 provided in the discharge piping near the outlet of the valve 16 for a to appear Referring to Figure 2 of the there is illustrated a schematic liagram of one form of electric circuit for use in controlling the operation the system of Figure in installations where it is desired that the entire contents of the extinguishant container be discharged when the valve is either automatically by the optical detector or manually in the manner lescribed in the above identified Tufts The optical detectors 10 are of the discriminating such as is in Patent issued June and each comprises two cells 26 and 28 connected in series across a voltage source described in the above identified the cells respond to different frequencies in such a manner that the voltage at the junction of the rises to a predetermined alarm voltage only when radiation flame is The voltage appearing at the junction of the cells is fed to the input a transistor amplifier 12 through diodes When the junction voltage reaches a predetermined the amplifier energizes a relay Rl to close relay contacts R1X1 to light a fire indicating light Bl and to energize the iolenoid 14 of the valve 16 to open the valve and discharge the contents of the 18 through the nozzles 1 Provision is made for either automatic or manual modes of operation by 2 means of switch When switch SI is in the automatic with contacts 3 S1X1 and S1X2 the energization of relay in addition to energizing 4 the solenoid also through the switch Si a feedback circuit through 5 line into the amplifier to maintain the amplifier in the energized 6 To further insure that the discharge of the once continues 7 until the container is and to provide means for on a master 8 control the fact that the discharge of extinguishant is taking 9 the pressure switch 24 is provided in the discharge The pressure switch is placed the discharge Tine just downstream from the solenoid and is normally but is closed by the pressure 12 that builds up in the discharge when the extinguishant discharges into the 13 from the valve The switch 24 is connected between the power source V and 14 the solenoid valve coil so that when the switch 24 is closed a circuit to 15 the solenoid is created through the switch 24 independently of the circuit 16 created by the amplifier The switch 24 also completes a circuit to a 17 light to provide a visual indication that the extinguishant is being 18 To operate effectively as a system capable of stopping the j 20 like burning of gasoline all of the components of the system must be 21 able to operate rapidly enough to cause discharge of the extinguishant into i 22 the compartment within about 200 milliseconds after Most of the time i 23 between appearance of radiation and the discharge of the extinguishan i 24 from the system is taken up by the operation of the to have 25 valve actuation to occur as rapidly as it has been found desirable 26 to energize the valve solenoid with a voltage greater than that for which the solenoid coil was For if the solenoid is intended to be operated by a six volt power it has been found that much greater speed of valve operation can be achieyed by energizing the solenoid from a 12 volt To prevent damage to the solenoid coil by the use of such excessive a timer 30 having normally closed contacts is inserted in series with the solenoid In one embodiment of the invention the timer is set to open its contacts and thereby break all circuits to the solenoid coil after the container of extinguishant has been completely Manual means may also be provided for opening the Such means the comprises means such as cable 32 attached to lever 34 for upsetting the pilot valve to cause opening of the main valve without energizing of the solenoid to accomplish such valve when extinguishant is released in this the pressure on the downstream side of the valve closes the pressure switch 24 to energize the Hence once the valve has been operated manually and the extinguishant has started to flow thereof will continue until the container is Hence the person operating the valve manually in an emergency not continue to hold the valve cable to insure complete The circuit to the solenoid may then be broken by either the opening of the pressure switch when the container is empty or by the timer switch In the illustrated the closing of the pressure switch 24 also completes a circuit to a feedback line to the amplifier so that the relay is energized to light the fire indicator light and to complete the same circuit to the solenoid that is created when a fire is detected 5 with the switch in the automatic Hence for any the switch is shifted to automatic from manual when the extinguishant is the automatic circuit to the solenoid is Although the extinguishant would continue to flow even without the automatic because of the circuit through the pressure automatic circuit may in some cases be used to power other such as external bells or other fire signal Since certain modifications may be made in the illustrated system without departing from the scope of the it is intended that all matter interpreted an illustrative and not a limiting with the switch ip the automatic Hence for any the switch SI is shifted to automatic from manual when the extinguishant is the automatic circuit to the solenoid is Although the extinguishant would continue to flow even without the automatic because of the circuit through the pressure the automatic circuit may in some cases be used to power other such as external bells or other fire signal Since certain modifications may be made in the illustrated system without departing from the scope of the it is intended that all matter contained herein be interpreted in an illustrative and not a limiting insufficientOCRQuality

Claims

I claim:

1. 1. A fire extinguishing system, comprising fire detecting means,

2. Extinguishant releasing means, and means detecting the released extinguishant 3 to maintain the extinguishant releasing means in the extinguishant releasing 4 condition. \ I 2. A fire extinguishing system, comprising. fire detecting means and 2 fire extinguishing means, said extinguishing means comprijsing-^a^supply of 3 pressurized extinguishant and a solenoid actuated valve for releasing the 4 extinguishant, amplifier means responsive to the detection of a fire by the 5 detecting means to energize the solenoid to open the valve and release the 6 extinguishant, and means responsive to the release of the extinguishant to 7 maintain said valve in the open position. I 3. A fire extinguishing system, comprising fire detecting means, and i fire extinguishing means, said extinguishing means comprising a supply of

3. Pressurized extinguishant and a solenoid actuated valve for releasing the 4 extinguishant to a discharge nozzle, means. responsive to the detection of a 5 fire by the detecting means to energize the solenoid of the valve to open the 6 valve to release the extinguishant to the discharge nozzle, and means responsive 7 to the increase in pressure downstream of the valve to complete a second 8 circuit to the solenoid, whereby said circuit remains energized so long as 10 the extinguishant is flowing.

4. A system as set out in claim 3 in which means is provided for opening the valve manually, whereby said pressure switch is operated tov energize the solenoid to hold the valve open so ;long as extinguishant is flowing. 45024/2 -Ψ'

5. A fir© detection and extinguishing system comprising a supply of pressurized extinguishant, valve means to release said extinguishant to a discharge nozzle, solenoid means for opening said valve, means responsive to infra-red radiation to produce a signal, means responsive to said signal to energize said solenoid to open the valve and release the extinguislaant, means to detect the release of the extinguishant, and means responsive to the detection of the released extinguishant to create another circuit path to said solenoid to maintain said solenoid energized so long as extinguishant is flowing. ND:dn - 8