US2168244A - Retard device for automatic fire control systems - Google Patents

Description

E. H. ROUSE Aug. 1, 1939.

RETARD DEVICE FOR AUTOMATIC FIRE CONTROL SYSTEMS Filed Dec. 18, 1934 Ill/Ill oRNEYi Patented Aug. 1, 1939 RETARD DEVICEFOR AUTOMATIC FIRE CONTROL SYSTEMS Edward H. Rouse, Thomaston, Conn, assignor to Automatic Sprinkler Company of America, Cleveland, Ohio, a corporation of Delaware Application December 18,1934, Serial No. 758,005

25 Claims.

My invention relates to automatic fire control apparatus wherein releasing devices are brought into action through theoperation of a heat actuated detector and has reference more particu- 5 larly to systems wherein said detector consists of a rate-of-rise temperature responsive device acting upon increase of temperature at a greater than a predetermined rate predetermined by the adjustment of the device or the intermediary del vices between the same and the releasing device.

The invention is particularly useful to those systems wherein the rate-of-rise device operates through expansion or change of air pressure condition and such change of pressure condition is -15 communicated to a pressure responsive diabe subject to abnormal changes of temperature incident to normal operations conducted in the building or plant where the same is installed and wherein such fluctuations do not necessarily indicate the presence of fire.

: The invention consists essentially in applying means for temporarily rendering the heat actuated detectors ineffective by modifying, neutralizing or nullifying the operation'of the intermediate devices between the same and the fire control mechanism such for instance as a valve controlling the flow of fire extinguishing fluid.

The invention is particularly useful also for installations wherein fans or blowers circulate the air in a way such that the circulated air will im- 0 pinge upon or affect the rate-of-rise device. The utility of my invention in such a plant finds an illustrative example in a paper making plant wherein the air is circulated todry the pulp by means of fans or blowersand wherein at the starting operation the conditions may be such that a change of temperature of an exceedingly great amount or rate due to the circulation of the air impinging upon the heat actuating device would in the absence of my invention call the 50 fire extinguishing appliance into operation.

The special utility of my invention in such an installation will be apparent from the statement below as to operating" conditions in a paper making plant, although, as will be obvious, the invention is equally'useful and advantageous in'its application to other plants or enclosures where an abnormal rate of rise of temperature is artificially produced.

My invention also consists in details of construction and combinations of devices as here- 5 after more particularly described and preferably involvesthe operation of a valve which is applied to the pressure conveying piping through which pressure is brought to the pressure responsive device, said valve being so constructed as tomodify such pressure or nullify the effect of the pressure mediumupon the pressure responsive device employed for governing the action of the fire control device and thereby temporarily disable the operation of the system. 5

It should be understood that while I have described the use of a heat detector which produces change of air pressure and operates on the rateof-rise principle I do not limit myself to such particular character of heat responsive device operatingthrough rate-of-rise of temperature but intend to cover by my claims any rate-of-rise device which upon operation releases or brings into operation a pressure which will act upon a pressure responsive diaphragm or other medium that is effective in bringing the release mechanism into action.

Referring now to the case of a paper making machine to which for sake of illustration my invention is herein shown as applied.

In a typical paper making plant it is usual to employ heat exchangers, sometimes called economizers, through which the heat of the heated vapor drawn from the machine by the blower or exhaust fan is used to heat fresh incoming air which is forced through suitable ducts into the machine room for circulation as the drying agent by passing over-the pulp or material to be dried. Due to the large quantitiesof vapor handled by the fans, the draft is very great, often 3000 lineal feet per minute. The heated vapor, as it leaves the paper machine, is heavily loaded with finely divided paper particles and is saturated with oil, grease and corrosive substances in suspension. These substances are deposited on the outer surr face of the corrugated metal boxes, enclosure and ducts of the economizer. The quantities of vapor involved can be visualized when it is considered that'the pulp supplied to the paper machine consists largely of water, which water must be evaporated before the paper is finished. Thus, for every ton of paper made, several tons of water must be vaporized and pass through the economizer. I Ordinarily, the material deposited on the boxes is wet and not highly inflammable, but "'65 are omitted. 1

As the-heat detectors A arelocatediniposition to be afiectedbyheated air incident to-the use of the manufacturing process, as for instance in the ducts or chambers through which theair is circulated during the operation of the plant, they may be at the temperature of the room or enclosure *which at times may be quite cold. When the process is started, such heated air reaching thermostats A may bring about a very rapid rate of increase in the temperature of the air contained in A, whereas there would be at that particular time no fire, with the result nevertheless that the fire control or extinguishing apparatus would be brought into operation although the action thereofis unnecessary or undesirable at this time,- as for instance on the resumption of operation of the machine after a shutdown.

In the particular manufacturing operation selected to illustrate the application of my invention S indicatesan electric motor obtaining its operating energy through electrical supply lines throughswitch Uused in starting and carrying on such' operation; Motor S dI'lVES. bloweriW causing air to' be drawn throughthe blower and discharged through economizer X. Y

To overcome the likelihoodaof operation by the heat detectors actuated underthese conditions,

I provide, in the preferred manner of carrying out my invention, a mercury valve acting as .a vent control and comprising essentially a body of mercury or other liquid which normally closes a ventconnected to the pressure conveying tube or some portion of the. apparatus in-whichthe change of pressure takes place for operating on the pressure responsive device andby suitable means; asfor. instancea magnet orsolenoid, change the position, or level. of said mercury or liquid to uncover orropen the vent, while the restoration of the liquid toits normalposition' or level effects the closing-of the vent ,and puts the apparatus in condition for normal operation. I The particular type of mercury valve show comprises a mercury holding dashpot 5 containing a body of mercury 6 the change of level ofwhich is efiectedqby the operation ofgthe plunger or liquid displacing element 4 under the control of the solenoid 2 .When the plunger is in the position shown in Fig. 2 in whichthe mercury 6 is at the level (if said mercury closes the branch or air vent tube 1 connected to 'the pressure conveying pipe B. At such time magnet or solenoid 2 is inactive-so that through thebias effected by the weight of 4 and associated parts the parts'will be in the position shown in that figure. When, however, the solenoid or magnet 2 is energized it draws the plunger or liquid displacing element 4 up into the position shown in Fig. 1 and temporarily maintains it in such position against the biasing action of gravity in which position the level of the mercury in. the dashpot or chamber 5 is allowed to fall thus uncovering the lower end of air tube 1, andpermitting the expanding air pressure in thermostat Ato escape to the atmosphere and temporarily nullify the effects of pressure or change of pressure. de-

*tion to one another; few seconds duration of time be desired, the positionof sliding contact 9' could be quite near the end of I!) so thatavery slight movement of the shown as asuitable starting switch U. Electrical connections'ohthe solenoid 2 suitable for this action; are shown diagrammatically as consisting of ;wiresor connections ll, I 2 and-l2' to which current issupplied throd'ghclosing the-control switch U for the motor Sr In the'conne'ctions 'l l-l2-l2' there isinterposed in the preferred form of-my invention, an electric switch the elements of which are indicated at 9' and H], such switch beinginterposed in the connection from wire- H to wire l2 leading to the control switch U. Said switch is normally closed but is caused to open after a predetermined interval of time to thereby break the circuit and thereby deenergize the solenoid 2 and allow the liquid displacing element 4 to drop back to the position shown in Fig. 2 and thus close the vent.

The-means for effecting the opening of the circuitat the switch 9'.-l Umay comprise an electric heating coil'8 which is connected to the circuit closed by the operation of switch U, by taps from the w ires I2-l2 as shown, said coil operating as a heating coil to cause distortion of the bi-metallicstrip 9 heated therein and attached to oneof the contacts as-for instance 9". The contact 9 "is caused to slide, by the action of the bi-metallic strip 9;" over contact l0 when current flows through coil8 so as to distort the element breaking'the electric circuit through solenoid 2, when the weight'of thearmature 2 and plunger 4 will allow these to assumefthe position shown in Fig. 2*and raise the'level'of mercury to 6 closing the outlet of tube 1 and putting the thermal system into normal fire detecting condition.

' The interva'lof time between the starting of the -motor' driven blower W and the breaking of contact between 9' and Ill can be made short or long by adjustingthe position of the parts, with rela- For-instance, should but a contact end of 9 would break contact. If, however, a longer period of time be desired, the distance that 9' would have to travel on IE! would be made proportionately greater.

Fig. 3 shows in-detail one way in which this period of time may be adjusted by adjustment of the position of the sliding contact 9 on the cooperating contact If) connected towire H; For

this purpose'the contact may be carried by an gadjustment'screw adjustable in the end of therthrough the action of. the vent valve may be readily adjusted since the effect'is. to prolong the magnet for opening the valve to prevent thereby creationof pressure from heat conditions,a blower acting to produce abnormal temperature changes when starting causing changes of pressure in the tube and means for energizing the magnet through the action of the starting means for the blower, said pressure conveying tube being in an environment influenced by the action of said blower.

8. In a fire control apparatus, the combination with a pressure conveying tubing in which pressure is produced under temperature changes for operating the apparatus, of an outlet valve con nected thereto and normally closed, means for opening the valve to prevent creation of pressure from abnormal changes of temperature other than those caused by fire and acting to cause pressure changes in the tubing, and means for closing the valve and for delaying the closing thereof to maintain the same open for a predetermined interval of time during the return of the abnormal temperature changes to normal conditions.

9. In a pressure controlled device, the combination with pressure conveying tubing in which pressure is produced under heat conditions resulting from fire, of a biased and normally closed vent valve for releasing pressure from said tubing, said valve being biased toward closed position, an electromagnet acting on the vent valve to open the same for venting the tubing and preventing operation of the pressure controlled device, under abnormal heat conditions not resulting from fire, and means for delaying the movement of said valve to closed position and thereby enable the abnormal heat conditions to become normal and the pressure to thereupon control the device under fire conditions.

10. In combination, a translating system adapted to supervise a progressively changeable atmospheric condition and to operate when said condition assumes a certain state, a condition changing system adapted to cause said condition to progressively change to said certain state, means for initiating operation of said condition changing system, and means set in operation on such initiating for disabling the translating system for operation at said certain state.

1 1. In combination, a translating system adapted to supervise a changeable temperature condition and to operate when said condition assumes a certain state, a temperature condition changing system adapted to cause said certain state, means for initiating operation-of said condition changing system, means set in operationby such initiating for disabling the translating system for operation at said certain state, and means for automatically again rendering the translating system normally operative after a predetermined time after the disabling thereof.

12. In combination, a translating system adapted to supervise a certain temperature condition subject to change and adapted to be set in operation by said condition when the rate of change exceeds a predetermined rate, operating means adapted when operated to change said condition at a different rate exceeding said predetermined rate, and means set in operation when said operating means is set in operation for preventing the operation of the translating means by said condition due to said difierent rate.

13. In a fire control apparatus having a pressure controlled operating element, a translating system including a heat detector and associated pressure producing means constructed and arranged to supervise a progressively changeable atmospheric condition and to produce a pres sure conditionof a degree to operate the fire control apparatus when said atmospheric condition assumes a certain state, a condition changing system constructed and arranged to cause said atmospheric condition to change for a time period to said certain state, means for initiating operation of said condition changing system, and means acting in the operation of said condition changing system for rendering the translating system ineffective for operation of the fire control apparatus during such time period and at said certain state.

14. In fire control apparatus having a pressure controlled operating element, a translating system including a heat detector and associated pressure producing means constructed and arranged to supervise a certain atmospheric condition subject to change and to produce pressure of a degree to set the fire control apparatus in operation on change of said condition to a cer-v tain state and when the rate of change of-temperature exceeds a predetermined rate, operating means adapted during a period of operation to change said condition at a different rate exceeding said predetermined rate, and means acting during such time period of operation of said operating means for preventing the operation of the translating means by said condition due to said difierent rate.

15. In combination, a fire control apparatus having a control system embodying operating means constructed and arranged to supervise a progressively changeable atmospheric condition and to set said apparatus into operation when said condition assumes a certain state, a condition changing system acting at a period of operation thereof to cause said condition to change to said certain state, and means acting in the operation of said condition changing system for rendering said operating means ineffective for setting the fire control apparatus in operation at said certain state.

16. In combination, a fire detector system con-- structed and arranged and normally efiective to.

operate upon an abnormal rate of rise of temperature, means external to said system for temporarily disabling it and rendering it ineffective forroperation when an abnormal rate of rise of temperature is artificially produced and automatic means for restoring said system to normal operation.

1'7. In combination, a fire detector system constructed and arranged to operate upon an abnormal rate of rise of temperature external to said system, means for rendering-said system ineiTective for operation during a period of time when the abnormal rate of rise of temperature is artificially produced, and means for automatically restoring said system to effective and normal operation at the end of such period of time to again render it responsive to a predetermined rate of rise of temperature.

18. In a fire detecting system, and in combination with an apparatus to be operated on the breaking out of a fire, an aerotube constructed and. arranged to be subjected to temperature changes producing pressure therein to operate the apparatus when the pressure increases at a rate greater than a predetermined rate, a device acting in operation to artificially produce a temperature change sufiicient to cause a pressure increase in the aerotube greater than said predetermined rate, and means acting in the operation of said device to reduce the pressure in the aerotube during said temperature change to prevent a pressure increase therein at a rate greater than the predetermined rate. r

19. In a fire detecting apparatus for use in a risk environment, a translating system in said enviromnent including pressure producing means adapted to supervise a progressively changeable atmospheric condition and to produce a pressure condition of a state to operate when said atmospheric condition assumes a certain state, a condition changing system adapted to cause said atmospheric condition to artificially change to said certain state, means for initiating operation of said condition changing system, and means set in operation on such initiating for disabling the translating system during such artificial change.

20. In a fire detecting apparatus for use in a risk environment, a translating system in said environment including pressure producing means adapted to supervise a progressively changeable atmospheric condition and to produce a pressure condition of a state to normally operate when said atmospheric condition assumes a certain state, a condition changing system adapted to cause said atmospheric condition to artificially change to said certain state, means for initiating operation of said condition changing system, means set in operation on such initiating for disabling the translating system during such artificial change, and means for automatically again rendering the translating system normally operative after a predetermined time after the disabling.

21. In combination, a thermally energized pressure generating translating system constructed and arranged to supervise a certain atmospheric condition subject to change and adapted to be set in operation by pressure generated under said condition when the rate of change exceeds a predetermined rate, operating means constructed and arranged to change said condition at a difierent rate exceeding said predetermined rate, and means set in operation when said operating means is set in operation for preventing generation of operating pressure and the operation of the translating means by said condition due to said different rate.

22. The combination of an enclosure, an apparatus responsive to changes in pressure for operating fire control mechanism including means responsive to an abnormal rate of change in temperature for effecting said change in pressure, the said means being located in said enclosure, operable means cooperating with said enclosure and which causes abnormal rates of temperature change therein when operation thereof is initiated, and means cooperating with said apparatus and responsive to initiation of operation of said operable means to render said pressure changes in the apparatus ineffective for a period of time commensurate with the duration of said abnormal changes in temperature resulting from the initiation of operation of said operable means.

23. In a fire control apparatus, the combination of a pressure operated control device responsive to pressure changes, a heat detector for producing such pressure changes, said detector being operative under heat conditions produced by fire and also under heat conditions artificially produced other than by fire to produce pressure sufficient to actuate said detector, a pressure control valve, means for moving said valve to a position to multiply or render efiective the action on the control device of the pressure changes developed by the heat detector, and means controlling said valve to shift the same in the presence of said artificial conditions to pressure nullifying position and to shift the same in the absence of such artificially produced pressure conditions to its efiective position to render the apparatus responsive to fire conditions.

24. In a fire control apparatus in an environment having an installation subject in normal operation to cause periodic abnormal heat changes not attendant upon fire conditions, the combination of a heat detector and means for governing the operation of the control apparatus through heating of the detector due to fire, and means responsive to abnormal rates of heat changes incident to operation of the installation for rendering the heat detector ineffectual to govern the action of said apparatus during said abnormal rates of heat changes taking place in the installation and incident merely to normal operation thereof but not attending a fire condition. V

25. The combination with fire control apparatus and a pressure actuated diaphragm installed in an enclosure subject to the operation of installations therein to abnormal artificially produced temperature changes other than those produced by fire, of means for developing changes of pressure upon temperature changes due to fire to operate the diaphragm, and means for nullifying or modifying said pressure during the presence of artificially produced abnormal temperature changes to render theapparatus irresponsive to said temporary abnormal changes of temperature occurring under normal operation of the installations in the plant. 7

' EDWARD H. HOUSE.

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