US3592270A

US3592270A - Double rate flow controller

Info

Publication number: US3592270A
Application number: US770248A
Authority: US
Inventors: William L Livingston
Original assignee: Factory Mutual Research Corp
Current assignee: Factory Mutual Research Corp
Priority date: 1968-10-24
Filing date: 1968-10-24
Publication date: 1971-07-13
Anticipated expiration: 1988-07-13

Abstract

A double-rate flow controller including a means for permitting fluid flow at a first high-flow rate, a means for reducing the first flow rate to a second lower flow rate and a means for regulating the volume of water passing through the flow controller during the high-flow condition before the high-flow rate is terminated and the low-flow rate begins.

Description

United States Patent Inventor William L. Livingston Sharon, Mass.

Appl. No 770,248

Filed Oct. 24, 1968 Patented July 13, 1971 Assignee Factory Mutual Research Corporation Turnpike, Mas.

DOUBLE RATE FLOW CONTROLLER 17 Claims, 3 Drawing Figs.

Int. Cl A621: 37/06 FieldotSeai-ch l69/l6,20,

References Cited UNITED STATES PATENTS Dahl Campbell et a1. Reid Zieg et a1. Parkison Scofield et a1. Ault Primary Examiner-Lloyd L. King Attorney-Lane, Aitken, Dunner & Ziems 138/46 239/534 X 169/20 169/20 x 138/46 169/42 X 169/42 X F 4F 3F 7 Jr 2 U [I no 4 I I: M

PATENTED JUL] 31971 INVENTOR WILLIAM L. LIVINGSTON DOUBLE RATE FLOW CONTROLLER BACKGROUND OF THE INVENTION The present invention relates to a fluid flow control device and more particularly to a fluid flow control device for use in a fire extinguishing system.

In a copending application entitled Method of Controlling Fire," Ser. No. 766,474 filed Oct. l0, I968, by the inventors William L. Livingston and Russel W. Pierce and assigned to the assignee of the present invention, a fixed fire extinguishing system is disclosed wherein fluid ablative material is formed by the addition of a water swellable polymer powder to water when the system is activated, which combines with the water and forms an ablative gel which is dispensed from sprinkler heads located over the fire. The gel material is substantially more viscous than plain water and tends to cling to the surfaces on which it is sprayed and therefore, its heat absorbing capabilities are substantially greater than plain water. An automatic fire extinguishing system using this ablative material is therefore effective at lower flow rates and with a lower overall volume of water than with conventional plain water systems. However, when the fluid ablative material is used in a conventional sprinkler system, health codes do not allow the ablative material to be maintained in the sprinkler system where the system is in fluid communication with the portable water supply. Since this is generally the situation with the majority of sprinkler systems presently in use, the gel forming material must be added to the water supply after the sprinkler system has been placed in operation. In a conventional wet pipe lire sprinkler system, initially the flow through the sprinkler head nozzles is pure water. The gelling powder which is subsequently added after the system commences operation, changes the pure water to the fluid ablative material. In fire extinguishing systems of this type it is desirable that the water and gel material mixture be built-up to the maximum concentration level as fast as possible to be the most effective. A feature equally important, is to build up an accumulation of ablative material at the fire exposure location in the shortest'possible time to maximize the fire extinguishing capabilities of the system.

To accomplish both of these ends, it is desirable that the system provide an initial high rate of flow from the sprinkler head nozzles. Subsequently, when the fluid ablative material is accumulated, the sprinkler flow may be reduced to a lower level sufficient to sustain the tire extinguishing capabilities of the system.

It is known to use various types of fluid flow control devices to regulate the rate of fluid flow, however, conventional flow control devices are not adequate for use in a fire extinguishing system of the type described above, where an initial high-flow rate at a high pressure is needed and where it is important tov regulate the volume and duration of the high-rate fluid flow.

SUMMARY OF THE INVENTION The present invention is directed to a double-rate flow control device adapted for use in a sprinkler-type fire extinguishing system and which permits an initial high-flow rate and a subsequent lower flow rate. This is accomplished by a flow regulating means including a pressure operated-dashpot to restrict the volume of fluid ablative material passing through the sprinkler system after a predetermined. volume has been passed through the flow control device.

Among the objects of the invention are the provision of a fluid flow control device adapted for use with fire extinguishing systems using fluid ablative material to initially maximize the buildup of the ablative material at a fire location, and sub sequently to maintain it at a sustaining level after the buildup of the material has been maximized, and the provision of a fluid flow control device for'permitting a first flow of fluid therethrough at a high-flow rate and a subsequent second lower flow. rate after a predetermined volume has been passed through the device at the first flow rate.

Other objects and further applicability of the present invention will become more apparent when taken from the detailed description given below in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a schematic diagram ofa fire extinguishing system including a cross section of the flow control device of the present invention shown in the high-flow position;

FIG. 2 is a cross section ofthe flow control device of FIG. 1- shown in the low-flow position and FIG. 3 is a view of the system taken along line 33 of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS iliary line 10. Each sprinkler head-6 is a conventional type and.

includes a nozzle I2 and a water deflector- 14 which is attached to the nozzle by means ofa yoke 16. In the nonoperative condition, the nozzle 12 is closed by means of'a' cap 18 maintained in position by means ofa fusible link 20. The nozzle portion of the sprinkler head assembly is threaded into the open end of the sprinkler head pipe line 4. The fire extinguishing system is preferably a wet pipe type, that is it contains water; although the invention is not restricted to such asystem.

The dual-rate flow control device of the present invention is generally designated by the reference numeral 30 in the;

drawings. It is normally positioned upstream of the sprinkler head nozzle 12in the sprinkler head pipe line 4. The flow control device 30 is formed of a circular mounting base 32.ma'de: of a noncorrosive metalic plate, placed in sealing engagementwith the inside of the sprinkler head pipeline 4. This is accomplished such as, for example, by spot welding prior to the assembly of the sprinkler system or by means of a threaded-con-- nection. The base 32 of the flow control device 30 includes a high-flow orifice 34 through which water is adapted to flow at a high rate when the system is activated. The orifice 34 is. formed by a tubular stand pipe 36, the lower end of which is attached integrally with the base 32. The upper portion of the stand pipe 36 extends vertically above the base 32v and includes a circular flange 38 having an annular recess 40 to receive a soft rubber O-ring seal 42.

The upstream end of the flow control device 30 is provided with a circular plate 44, the outside perimeter ofwhich generally corresponds to and is slidable within the interior ofthe sprinkler head pipeline 4. The plate 44 includes a pluralityof small fluid flow apertures 46 equally spaced apart in a radial directionin the plate 44, as shown in FIG. 3. One of theapertures 46a is positioned in the center of the plate 44 'so as to be directly over the-high-flow orifice 34. Although four apertures 46, in addition to the center aperture 460, are illustrated, it-

which is secured to the plate 44. The bellows 48, is filled with air when the system is in the nonoperative condition. The bellows 48 is vented to the atmosphere by means of a vent 50 which communicates with the bellows interior through an' opening 52in the base 32. The rate of venting of the air from within thebellows 48 may be regulated in-part by =the size of" the vent 50.

The operation of the flow controlled device-.will now be. described. In the static or no flow condition'of'th'e'fire'extin guishing system,-water is present in thepipeline 4.-'As shown in".

FIG. 1, the plate 44 of the flow control device 30 is maintained in the upstream position by means of the dashpot bellows 48. Since water is present in a static condition on either side of the plate 44 there is no pressure differential acting upon the plate 44 and air is not vented within the bellows 48.

During a fire condition, temperatures of the surrounding area are raised and the fusible link 20 melts to release the cap 18 and open the nozzle 12. Water then begins to flow through the sprinkler 6 from the head pipeline 4 at a fairly rapid flow rate and is discharged onto the fire location. Further upstream, the gelling powder material from the supply 8 is mixed with the plain water from the supply 2 to form the fluid ablative material. With the plate 44 in the upstream position, the initial high'flow rate is maintained since the fluid ablative material flows through all of the small apertures 46 and on through the high-flow orifice 34. This permits the gelling material to be completely mixed with the plain water in a minimum amount of time and maximizes the buildup of the fluid ablative material at the fire location. As the fluid ablative material continues to flow in the pipe line 4 and through the flow control device 30, the line pressure gradually builds up upon the upstream side of the plate 44 forcing it downwardly against the resistance of the air-filled bellows 48 This causes the air to be gradually vented front the interior of the bellows 48 through the vent 50, which inturn allows the plate 44 to gradually move downwardly toward the baseplate 32 and the high-flow orifice 34.

After a sufficient amount of air has been expelled from the bellows 48 due to the pressure of the flowing fluid ablative material against the plate 44, the low-flow position, as illustrated in H0. 2, is reached. At this point the plate 44 is clamped against the flange 38 and the O-ring seal 42 of the stand pipe 36 by the fluid pressure in such a way so that only the center aperture 46a on the plate 44 remains in flow communication with the high-flow orifice 34. A seal is maintained at this point by the line pressure and only the fire ablative material flowing through the center aperture 46a is permitted.

to pass through the high-flow orifice 34. It will be appreciated since the center aperture 460 is smaller than the openingof the high-flow orifice 34, the amount of fluid ablative material passing through the nozzle 12 and onto the fire location is substantially reduced.

Rate of flow is proportional to pressure and time and by determining the constants of the system, the sprinkler system .can be adapted to permit a predetermined volume of fluid ablative material through each sprinkler head 6 at the highflow rate before the flow control device 30 acts to reduce the flow rate to the lower sustaining level. It will be appreciated that bellows will vent faster at high pressures and as such the flow control device 30 becomes a flow integrator to maintain a substantially constant volume of high-rate fluid flow.

Thus with the fluid flow control device of the present invention, an initial high-fluid flow rate is provided to allow the gel material to build up to a maximum at the fire location. For example, it has been found that the volume of fluid ablative material which accumulates after approximately 15 minutes at the high-flow rate is sufficient under normal sprinkler system pressures to insure the maximum fire extinguishing capabilities of the system. By calculating the venting rate of the bellows 48, the size of the vent 50 may be established to insure the desired duration of flows at the high-fluid flow rate. After the high-rate fluid flow, the flow of fire ablative material is continued at a lower flow rate sufficient to sustain the fire extinguishing capabilities of the system and maintained at this rate until the fire is extinguished and the system shutoff.

Generally. the fire extinguishing systemis not used more than once, however, the fluid flow control device of the present invention may be reused by reinflating the dashpotbellows to reset the upper plate to its-static flow position.

It will be appreciated that the above description of the double-rate flow control device is illustrative only and numerous modifications and variations may be made in light of the above teachings. it is therefore to be understood that within the scope ofthc appended claims, the invention may be practiced otherwise than as specifically described herein.

I claim:

1. A fluid sprinkler fire extinguishing system comprising a fluid supply source, a plurality of sprinkler heads, closure means normally preventing the flow of fluid from said fluid supply source through said sprinkler heads, means responsive to a fire condition to release said closure means and initiate fluid flow through said sprinkler heads, and fluid flow control means to regulate the rate of fluid flow through said sprinkler heads, said control means being automatically responsive directly to supply pressure at each of said heads and time duration of flow through said heads respectively, thereby to change the rate of fluid flo,w upon the passage through each head of a predetermined volume of fluid after initiation thereof.

2. The system of claim 1 wherein said fluid flow control means comprises means for passing fluid at a first flow rate and means for reducing said first flow rate to a second flow rate after the passage of a predetermined amount of fluid at said first flow ratev 3. The system of claim 2 wherein said fluid flow control means further comprises means to regulate the operation of said reducing means to initiate said second flow rate.

4. The system of claim 3 wherein said fluid control means is a fluid flow controller having a first fluid passage to pass fluid at a first flow rate and a second fluid passage to pass fluid at said second flow rate,

5. The system of claim 4 wherein said regulating means comprises a dashpot assembly for regulating the operation of said controller at said first and second flow rates.

6. The system of claim 5 wherein said dashpot assembly includes means forming said first fluid passage when it is in a first position and means forming said second fluid passage I fluid supply source, a plurality of sprinkler heads, means coupling said sprinkler heads and said fluid supply, means responsive to a fire condition for activating said sprinkler heads to initiate flow therethrough, a fluid flow controller having a first fluid passage to pass fluid at a first flow rate and a second fluid passage to pass fluid at a second flow rate, and a dashpot assembly for regulating the operation of said controller at said first and second flow rates in first and second positions, respectively, said dashpot assembly including means forming a high-flow orifice and a plurality of low-flow orifices in fluid communication with said high-flow orifice when said dashpot assembly is in said first position to establish said first fluid passage, said second fluid passage being established by said highflow orifice and one of said plurality of low-flow orifices being in fluid communication with said high flow orifice when said dashpot assembly is in said second position.

8. The system of claim 7 wherein said dashpot assembly comprises a base including said high-flow orifice and a plate including said plurality of low-flow orifices, said plate being movable with respect to said base by said regulating means.

9. The system of claim 8 wherein said dashpot assembly includes a chamber being adapted to be filled with air, said chamber in its filled condition maintaining said assembly in said first position corresponding to said first flow rate whereby said plurality of low-flow orifices are spaced from and in flow communication with said high-flow orifice and said chamber in its empty condition maintaining said assembly in said second position corresponding to said second flow rate whereby all but one of said plurality of low-flow orifices are positioned out of fluid communication with said high-flow orifice 10. The system of claim 9 wherein said chamber comprises a bellows attached between said base and said plate adapted to be filled with air, said bellows being filled with air in said first flow rate position and said bellows being emptied of air in said second flow rate position.

11. The system of claim wherein said dashpot assembly further includes means for venting said chamber in response to fluid pressure caused by fluid flow from said fluid supply through said sprinkler heads.

12. A sprinkler head for use in a fire extinguishing system having a fluid supply source, said head comprising closure means normally preventing the flow of fluid from said fluid supply source through said head, means responsive to a fire condition to release said closure means and initiate fluid flow through said head, and fluid flow control means to regulate the rate of fluid flow through said head, said control means being automatically responsive directly to supply pressure at said head and time duration of flow through said head respectively, thereby to change the rate of fluid flow upon the passage through said head of a predetermined volume of fluid after initiation thereof.

' 13. The system of claim wherein said fluid flow control means comprises means for passing fluid at a first flow rate and means for reducing said first flow rate to a second flow rate after the passage of a predetermined amount of fluid at said first flow rate.

14. The system of claim 13 wherein said fluid flow control means further comprises means to regulate the operation of said reducing means to initiate said second flow rate.

15. The system of claim 14 wherein said fluid control means is a fluid flow controller having a first fluid passage to pass fluid at a first flow rate and a second fluid passage to pass fluid at said second flow rate.

16. The system of claim 15 wherein said regulating means comprises a dashpot assembly for regulating the operation of said controller at said first and second flow rates.

17. The systemof claim 16 wherein said dashpot assembly includes means forming said first fluid passage when it is in a first positionand means forming said second fluid passage when it is in a second position.

UNITED STATES PATENT OFFICE W CERTIFICATE OF CORRECTION Patent No. 3,59 7 Dated Julv l1, lQ'Zl Inventor(s) willlam Livlngston It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 10, change "766, 47 l" to --766,U75-.

Column 1, line 27, change "portable" to -potable--.

Column 2, line 10, change "highflow position" to -high flow rate position-.

Column 2, line 12, change "low-flow position" to -low flow rate position. Column 5, line 17, and column 6, lines 4, 7, 11 and 1,

"system" should be head-. Column 5, line l7, "15" should be --l2-.

Signed and sealed this 2nd day of May 1972.

(SEAL) Attest:

EDWARD M.FLETCHER, JR. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents

Claims

1. A fluid sprinkler fire extinguishing system comprising a fluid supply source, a plurality of sprinkler heads, closure means normally preventing the flow of fluid from said fluid supply source through said sprinkler heads, means responsive to a fire condition to release said closure means and initiate fluid flow through said sprinkler heads, and fluid flow control means to regulate the rate of fluid flow through said sprinkler heads, said control means being automatically responsive directly to supply pressure at each of said heads and time duration of flow through said heads respectively, thereby to change the rate of fluid flow upon the passage through each head of a predetermined volume of fluid after initiation thereof.

2. The system of claim 1 wherein said fluid flow control means comprises means for passing fluid at a first flow rate and means for reducing said first flow rate to a second flow rate after the passage of a predetermined amount of fluid at said first flow rate.

3. The system of claim 2 wherein said fluid flow control means further comprises means to regulate the operation of said reducing means to initiate said second flow rate.

4. The system of claim 3 wherein said fluid control means is a fluid flow controller having a first fluid passage to pass fluid at a first flow rate and a second fluid passage to pass fluid at said second flow rate.

6. The system of claim 5 wherein said dashpot assembly includes means forming said first fluid passage when it is in a first position and means forming said second fluid passage when it is in a second position.

7. A fluid sprinkler fire extinguishing system comprising a fluid supply source, a plurality of sprinkler heads, means coupling said sprinkler heads and said fluid supply, means responsive to a fire condition for activating said sprinkler heads to initiate flow therethrough, a fluid flow controller having a first fluid passage to pass fluid at a first flow rate and a second fluid passage to pass fluid at a second flow rate, and a dashpot assembly for regulating the opeRation of said controller at said first and second flow rates in first and second positions, respectively, said dashpot assembly including means forming a high-flow orifice and a plurality of low-flow orifices in fluid communication with said high-flow orifice when said dashpot assembly is in said first position to establish said first fluid passage, said second fluid passage being established by said high-flow orifice and one of said plurality of low-flow orifices being in fluid communication with said high flow orifice when said dashpot assembly is in said second position.

9. The system of claim 8 wherein said dashpot assembly includes a chamber being adapted to be filled with air, said chamber in its filled condition maintaining said assembly in said first position corresponding to said first flow rate whereby said plurality of low-flow orifices are spaced from and in flow communication with said high-flow orifice and said chamber in its empty condition maintaining said assembly in said second position corresponding to said second flow rate whereby all but one of said plurality of low-flow orifices are positioned out of fluid communication with said high-flow orifice

10. The system of claim 9 wherein said chamber comprises a bellows attached between said base and said plate adapted to be filled with air, said bellows being filled with air in said first flow rate position and said bellows being emptied of air in said second flow rate position.

11. The system of claim 10 wherein said dashpot assembly further includes means for venting said chamber in response to fluid pressure caused by fluid flow from said fluid supply through said sprinkler heads.

13. The system of claim 15 wherein said fluid flow control means comprises means for passing fluid at a first flow rate and means for reducing said first flow rate to a second flow rate after the passage of a predetermined amount of fluid at said first flow rate.

17. The system of claim 16 wherein said dashpot assembly includes means forming said first fluid passage when it is in a first position and means forming said second fluid passage when it is in a second position.