US3139143A

US3139143A - Fire protection system

Info

Publication number: US3139143A
Application number: US212963A
Authority: US
Inventors: Carmen J Renda
Original assignee: Automatic Sprinkler Corp
Current assignee: Automatic Sprinkler Corp
Priority date: 1962-07-27
Filing date: 1962-07-27
Publication date: 1964-06-30
Anticipated expiration: 1981-06-30

Description

June 30, 1964 c. J. RENDA 3,139,143

FIRE PROTECTION SYSTEM Filed July 27, 1962 2 Sheets-Sheet l CONTQOL. AMPLIFIEQ INVENTOR. Carmen c]. Pena/a [WWW ATTORNEY.

June 30, 1964 c. J. RENDA 3,139,143

FIRE PROTECTION SYSTEM Filed July 27, 1962 2 Sheets-Sheet 2 J g A l? INVENTOR. CarmendPe/vaa UESQQQ Q 3 Ekb W \h m l t-l Q Q2806 9 +0$$$QQ Q csacaw ATT RNEY.

United States Patent 3,139,143 FREE PROTECTEON SYSTEM Carmen J. Renda, Youngstown, Ghio, assignor, by mesne assignments, to Automatic Sprinkler Corporation of America, Youngstown, Ohio, a corporation of Ohio Filed July 27, 1962, Ser. No. 212,963 7 Claims. (Cl. 1169-19) This invention relates to a fire protection system and more particularly to a system capable of extremely fast detection of fire and minimum time lapse in delivering an extinguishing agent on the fire.

The principal object of the invention is the provision of a fire protection system that will detect fire and deliver a fire extinguishing agent on the fire in the elapsed time range of a few milliseconds.

A further object of the invention is the provision of a fire protection system in which the detection apparatus includes sensors instantaneously responsive to predetermined wave lengths in the electromagnetic spectrum which are characteristic of combustion of the material being protected.

A still further object of the invention is the provision of a fire protection system that includes electronic sensor units in its detection section and a responsive electronically actuated self-powered valve in its extinguishing agent controlling section.

A further object of the invention is the provision of a fire protection system capable of detecting a fire and delivering a fire extinguishing agent on the fire in a few milliseconds to effectively control a fire in an extremely hazardous material such as rocket propellants and similar self-oxidizing materials.

A still further object of the invention is the provision of a fast acting fire protection system designed for hazards where utmost speed is essential for effective fire control and in which the fire detection apparatus utilizes photoconductors so designed as to discriminate between certain portions of the electromagnetic spectrum and wherein the detectors are arranged in a balanced system to insure desirable response.

The fire protection system disclosed herein was conceived specifically for flash fire suppression. Where speed is of the utmost importance, a system capable of operating in the milliseconds range is needed to detect and extinguish fire at its very inception. The presently disclosed system accomplishes this primary object by utilizing electromagnetic detection which is arranged to respond to a portion of the electromagnetic spectrum as is produced by the burning of the material protected. A control unit comprising a portion of the system provides convenient connections between the detecting system and the extin guishing agent delivery portions of the system and provides continuity tests for the detection and actuation circuits connected therethrough. The fast acting valve controlling the fire extinguishing agent is operated by electronic detonation of an explosive charge which unlatches the clapper allowing the extinguishing agent to flow from the applicators. The system is so designed and arranged that it utilizes fully primed piping so that the extinguishing agent is at the applicators ready to flow when the system is actuated. Alarm signals such as horns, sirens, bells, lights, etc., may be added as desired. The system is arranged to be responsive to fire in the material protected and additionally to guard against false response to normally present electromagnetic spectrum sources.

With the foregoing and other objects in view which will appear as the description proceeds, the invention resides in the combination and arrangement of parts and in the details of construction hereinafter described and claimed, it being the intention to cover all changes and modifications of the example of the invention herein chosen for purposes of the disclosure, which do not constitute departures from the spirit and scope of the invention.

The invention is illustrated in the accompanying drawing, wherein:

FIGURE 1 is a schematic view of the complete fire protection system.

FIGURE 2 is a symbolic diagram of the electromagnetic detection portions of the fire protection system illustrated in FIGURE 1.

FIGURE 3 is a symbolic diagram of the control amplifier portion of the fire protection system. illustrated in FIGURE 1.

FIGURE 4 is a symbolic diagram of a time delay testing circuit used in connection with the control amplifier shown in FIGURE 3.

By referring to the drawings and FIGURE 1 in particular, a symbolic illustration of the fast acting fire protection system may be seen. The supervised area having the hazard to be protected is located at A. Fire extinguishing agent applicators 10, 10 are arranged adjacent thereto and directed thereon and the applicators 10, 10 are preferably nozzles with blow-out plugs. One or more sensors 11 are adjustably positioned as close to the hazard area A as practical. The applicators 10 are in communication with extinguishing agent supply piping 12 which in turn communicates with a fast acting deluge valve 13 which is of the explosive charge actuated type and which in turn is in communication with an extinguishing agent supply pipe 14. The explosive charge by which the fast acting valve 13 is operated is disclosed in the co-pending application for patent of Wayne E. Ault, Serial No. 200,122 and as disclosed therein and in FIGURE 1 hereof, the explosive charge is actuated by an electrical circuit 15 which is illustrated and indicated as a double conductor cable connecting the explosive actuated portion 16 of the valve 13 with a control amplifier generally indicated at 17.

Still referring to FIGURE 1 of the drawings, it will be seen that the sensor 11 which is shown in operative relation to the hazard area A is an infrared detector and comprises a solid state type of photoconductor so designed as to discriminate between certain electromagnetic waves. As used herein the electromagnetic wave sensor'will respond to the near infrared area of such electromagnetic waves. The sensor 11 includes three units arranged to form a voltage divider and is electrically connected at a signal takeoff point as hereinafter described to the control amplifier 17 by a multiple conductor cable '18. The control amplifier 17 is supplied with suitable energy from a power source 19 by way of conductors 20.

In addition to the sensor 11 positioned in proximity to the hazard area A, one or more heat actuated devices 21 are positioned in proximity thereto and in communication with tubing 22 which extends to an electrical control 23. The electrical control 23 is a device heretofore known in the art in which an air pressure actuated diaphragm controls an electric switch so that fire in the area of the heat actuated devices 21 will increase air pressure in the heat actuated device 21, the tubing 22 and act to move the diaphragm and close the electric switch in the electrical control 23 and thereby close an electric circuit comprising a two-conductor cable 24 which in turn communicates with the control amplifier 17.

In the unlikely event of the failure of the sensor 11 to actuate the system, the heat actuated devices 21 will provide the necessary actuation and the positive operation of the fire protection system is thus assured.

, It will thus be seen that fire in the hazard area A will result in the operation of the fast acting valve 13 and the delivery of the fire extinguishing agent through the primed piping 12 of the applicators 10 in the matter of milliseconds and such speeds are effectively used in extinguishing fires in materials or fuels containing their own oxidizing agents where the control of the fire is occasioned by lowering the temperature to a point below that necessary for ignition.

The principal point of novelty in the present fire protection system is the electromagnetic detecting and actuating circuitry and the sensors 11 which comprise part of it, and which circuitry operates at electronic speeds to open the extinguishing agent control valve 13 in milliseconds making possible the efliective control of fire in extremely hazardous materials.

By referring now to FIGURE 2 of the drawings, a symbolic diagram of the electromagnetic system may be seen and it will be observed that two of the sensors 11 are illus trated as being electrically connected by multiconductor cables to a terminal strip 25 which in the example illustrated includes twelve numbered terminals. One of the sensors 11 has four-circuit wires connected to numbered

terminals

1, 2, 9 and 11 while the other sensor 11 has its four circuit wires connected to the numbered

terminals

1, 3, 8 and 11. The conductors extending from the first sensor, the uppermost one as seen in FIGURE 2 of the drawings, includes a signal conductor 1 connected with numbered terminal 2; a test conductor 1 connected with numbered terminal 9 and the other sensor 11 includes a conductor indicated as signal 2 connected to numbered terminal 3 and a conductor labeled test 2 connected with numbered terminal 8. It will be observed that another sensor can be connected to numbered terminals 4 and 7 so that three sensors can be connected to the terminal strip 25.

The numbered

terminals

2, 3 and 4 are directly connected with the control amplifier 17 and by referring to FIGURE 3 of the drawings, a symbolic diagram of the same may be seen, it being observed that the diagram includes the representation of one of the sensors 11 which includes a photoresistor marked blue, a photoresistor marked red and a photoresistor marked compensator and that the current flow is from reference point 26 through the photoresistors marked blue, red and compensator to a reference point 27.

Conductors

28 and 29 are connected to the

respective reference points

26 and 27. A signal takeoff point indicated by reference numeral 30 is lo catedadjacent the photoresistor marked red, and those skilled in the art will realize that these three photoresistors form a voltage divider. As photons of different wave lengths fall on the photoresistors, the voltage at signal takeoff point 30 will vary. A resistor 31 is connected between a lead 32 in connection with the signal takeoff point 30 and the conductor 28. The resistor 31 is used to compensate for the high, dark resistance of the blue photoresistor cell,

Diodes

33, 34 and 35 act as gates for the signals from the different sensors. When the circuit between reference point 26 and reference point 27 is unbalanced in such a way that the voltage at signal point 30 increases as occasioned by a resistance decrease in the red photoresistor cell, the gate diode 33 will allow current to flow from the base of transistor 36 causing current to flow through a resistor 37, transistor 38 and transistor 39. This current is of the same" magnitude but does cause an impedance change in the cascaded common collector amplifier (input several megohms, output across resistor 37 100 k. ohms). The current flow through resistor 37 causes a voltage distribution such that the ground end is zero and the junction ofresistor 37, transistor 38 and diode 40 is positive Diode 40 is a 15 volt zener diode used to gate all signals below that potential. A decrease in resistance of the red photoresistor cell which causes an increase in current fiow through resistor 37 raising the voltage at the junction of resistor 37, transistor 38 and diode 40 beyond 15 volts will cause the base'of transistor 39 to bias the transistor into conduction. Current will then flow from ground up through resistor 41, diode 42 and transistor 39. This current flowing through resistor 41 causes the junction of resistor 41, diode 42 and silicon control rectifier 43 to become positive When the voltage approaches positive 2 volts, the silicon control rectifier will transfer into an on condition. The silicon control rectifier 43 circuit consists of resistor 44, the primer and resistor 45. The primer resistance is on the order of an ohm and is placed in parallel with resistor 44. Resistor 45 is a current limiting resistor. Resistor 44 comes into play only after the primer is fired. The current through resistor 44 causes the voltage on the gate lead of silicon control rectifier 46 to increase and allows the silicon control rectifier 46 to go into conduction and cause the actuation of the auxiliary circuit. The circuit of silicon control rectifier 43 and silicon control rectifier 46 allow a delay between the primer and auxiliary actuations which may be used to advantage when a secondary fire extinguishing system in the area is employed and its fire extinguishing agent supply taken from the same source as that communicating with the supply line 14 heretofore referred to. By referring now to FIGURE 4 of the drawings, it will be observed that a time delay circuit used in testing the hereinbefore described circuitry to the sensor 11. is disclosed. Reference points 47 and 48 in FIGURE 3 are electrically connected with reference points 47A and 48A in FIGURE 4 when the time delay circuit is used. The circuit of FIGURE 4 is used when a delay is needed between test and operating conditions in the actual unit associated with the control amplifier 17 as seen in FIG- URE 2 of the drawings. When used and in test position current will flow through relay 49 charging capacitor 50. As relay 49 pulls in, contacts 51 will open cutting off the voltage to the Z match amplifier, sensor 11 and the control amplifier 17. Capacitor 50 feeds voltage to relay 49 holding contacts 51 open until the control amplifier 17 and its associate control has been returned to an operating condition. By referring now to FIGURE 2 of the drawings, it will be observed that in addition to the control amplifier 17 which has been hereinbefore described, the circuitry includes test circuits and switches for controlling the same and the following operational description of the system will indicate their use.

When power is applied to the system by closing switch 52, a White indicating light 53 is illuminated indicating the system is energized. Current will flow from ground at numbered terminal 11 on terminal strip 25 through the sensor cable 18 and return to numbered terminal 10 on terminal strip 25 energizing relay 54. The lower contact of relay 54 connects a lamp 55 to a 24 volt power source. A light 55 indicates that a complete sensor circuit is in service. The upper contact of relay 54 (deenergized position) connects a trouble buzzer 56 to the 24 volt circuit so that the sounding of the buzzer 56 indicates an open circuit on the sensor line. Relay 54 has an additional set of contacts 54A that may be used to control external power equipment in case of trouble. When signal lights 53 and 55 are illuminated, the system is ready for operational test. I

Switches generally indicated at 57, 58 and 59 are multiple circuit sensor test switches. In a typical system one such switch is used for each sensor used. The circuitry of FIGURE 2 illustrates the

switches

57, 58 and 59 and three sensors and it will be understood that more may be employed. The uppermost section of the multiple circuit sensor test includes

switches

57A, 58A and 59A and these momentarily interrupt the supply voltage to the sensors 11 and the control amplifier 17. This guards against false actuation due to switching transients and will automatically reset the silicon control rectifier units 43 and 46. The next lower section of the switches indicated at 57B, 58B and 59B disconnects the control amplifier 17 from the primer circuit and connects it to the test lamp 60., The test lamp 60 will light when the sensor 11 detects the infrared from a built-in test light or receives voltage from the diode depending on which is used. The next-section of the switches indicated at 57C, 58C and 59C connects the 24 volt power supply to the sensor lead which connects to the built-in test light or diode. When heat from the built-in test light falls on the photoresistor cell of the sensor 11 the voltage on the signal lead will increase causing the control amplifier 17 to fire or gate the silicon control rectifier 43. When this occurs, current will flow through the test lamp 60, the switch 5813, the silicon control rectifier 43 and resistor 45 to the 24 volt power supply. The illumination of test lamp 69 comprises a check of the complete system excluding the primer and auxiliary circuit. The next lower portion of the

switches

57, 58 and 59 comprises the

contacts

57D, 58D and 59D and they act to disconnect the control amplifier 17 from the auxiliary circuit to assure against false actuation. The

switches

57, 58 and 59 are connected so that only one sensor 11 can be tested at a time.

A continuity tester for the primer and auxiliary circuit is provided and comprises a multiple contact switch 61 including contacts 61A, 61B and 61C and a meter 62. When the switch 61 is in central position the meter 62 is connected to the 24 volt power supply through resistors 63 and 64 and potentiometer 65. In this position the meter 62 indicates the voltage used for continuity testing. Such voltage is set by the potentiometer 65. Adjusting the voltage indicated on meter 62 to the same point each time will indicate the slightest change in the resistance of the primer bridge wire or auxiliary circuits. The contacts 61B and 61C connect the primer or auxiliary circuit across meter 62 and through the calibration potentiometer 66 or 67. In the primer position (left of center) contacts 61B and 61A connect the primer across the meter 62 as a meter shunt. A potentiometer 67 is then adjusted so that the meter 62 reads at mid-scale. The sensitivity of the meter 62 is such that any change in primer resistance will be indicated. Thus, if the primer is open the meter 62 will read full scale. Still referring to this portion of the system, it will be observed that there is a diode 68 connected across the meter 62 in such a manner as to act as a non-linear resistor, and it therefore protects the meter 62 against burn-out. The resistor 64 heretofore referred to acts as a current limiter for the primer under test conditions. When switch 61 is in the auxiliary position (right of center) the same test conditions take place for the auxiliary as outlined for the primer. A manual switch 69 including a secondary contact 6913 provides for manual firing and is so connected that when it is closed the 24-volt power supply will be connected directly to the primer and auxiliary circuit causing both to actuate.

An alarm light 7 0 is connected with the primer circuit in parallel so that it will light and stay lit in case of actuation of this circuit. To restore the system to operational condition, a reset switch 71 must be depressed restoring silicon control rectifiers 43 and 46 to the reset condition, the actuation of the reset switch 71 also disconnects the alarm light 70.

It will be seen that a complete description of the fire protection system including the various portions thereof rendering the system of electromagnetic detection responding to a portion of the electromagnetic spectrum has been disclosed and that an additional description of the continuity tests for the actuation and detection circuits connected therethrough has been included. Legends on the drawing in addition to the reference numerals are referred to in the specification for a clearer understanding of the invention, its operation and its components and 6 it will thus be seen that a fire protection system meeting the several objects of the invention has been disclosed and having thus described my invention, what I claim is:

1. In a fire protection system, apparatus comprising means for delivering a fire extinguishing agent, means controlling said fire extinguishing agent delivering means and means for generating and transmitting a trigger signal to said controlling means, said means for generating and transmitting said trigger signal including a control armplifier, electromagnetic wave sensitive photoresistors coupled to said control amplifier, said electromagnetic wave sensitive elements operable to discriminate between certain electromagnetic waves, said control amplifier including gate means coupled to said electromagnetic wave sensitive elements and responsive to an unbalanced output from said electromagnetic wave sensitive elements, and pulse generating means coupled to said gate means for generating said trigger signal, said photoresistors responsive to portions of the electromagnetic spectrum encompassing the near infrared area.

2. The combination of claim 1 and wherein said electromagnetic wave sensitive photoresistors comprise solid state type photoconductors responsive to portions of the electromagnetic spectrum encompassing the near infrared area of said electromagnetic waves.

3. The combination of claim 1 and wherein said electromagnetic wave sensitive photoresistors include three units arranged to form a voltage divider electrically connected to said control amplifier at a signal take-off point and wherein one of said units is responsive to the near infrared area of said electromagnetic waves, another portion is responsive to the visible portion of said electromagnetic wave spectrum and a third portion arranged to n act as a compensator.

4. In a fire protection system, apparatus comprising means for delivering a fire extinguishing agent, electronically actuated means controlling said fire extinguishing agent delivering means responsive in operation to a trigger signal and means for generating and transmitting a trigger signal to said controlling means, said means for generating and transmitting said trigger signal comprising a solid state type photoconductor including a red photoresistor cell, a blue photoresistor cell, and a compensating photoresistor cell responsive to the near infrared area of the electromagnetic spectrum, a control amplifier coupled to said photoconductor including pulse generating means for generating said trigger signal and gate means including a gate diode responsive in actuation to said photoconductor and controlling said pulse generating means.

5. The combination of claim 4 and wherein said control amplifier includes a cascaded common collector circuit coupled to said gate diode and comprising an impedance element establishing a normal potential and wherein a zener diode is coupled to said impedance element and acts to gate all signals below said normal potent ial.

6. The combination of claim 4 and wherein a silicon controlled rectifier is coupled to said pulse generating means.

7. The combination of claim 4 and wherein a silicon controlled rectifier is coupled to said zener diode.

References Cited in the file of this patent UNITED STATES PATENTS 2,570,280 Roifman Oct. 9, 1951

Claims

1. IN A FIRE PROTECTION SYSTEM, APPARATUS COMPRISING MEANS FOR DELIVERING A FIRE EXTINGUISHING AGENT, MEANS CONTROLLING SAID FIRE EXTINGUISHING AGENT DELIVERING MEANS AND MEANS FOR GENERATING AND TRANSMITTING A TRIGGER SIGNAL TO SAID CONTROLLING MEANS, SAID MEANS FOR GENERATING AND TRANSMITTING SAID TRIGGER SIGNAL INCLUDING A CONTROL AMPLIFIER, ELECTROMAGNETIC WAVE SENSITIVE PHOTORESISTORS COUPLED TO SAID CONTROL AMPLIFIER, SAID ELECTROMAGNETIC WAVE SENSITIVE ELEMENTS OPERABLE TO DISCRIMINATE BETWEEN CER-