US2988150A

US2988150A - Fire extinguisher

Info

Publication number: US2988150A
Application number: US675661A
Authority: US
Inventors: Alonzo L Smith
Original assignee: Individual
Current assignee: Individual
Priority date: 1957-08-01
Filing date: 1957-08-01
Publication date: 1961-06-13
Anticipated expiration: 1978-06-13

Description

June 13, 1961 A. L. SMITH FIRE EXTINGUISHER Q 1 m2 %m a w w m w. A w 0 MK MN Z m m f/ Z A %w Filed Aug. 1, 1957 United States Patent 2,988,150 FIRE EXTINGUISHER Alonzo L. Smith, P.O. Box 6252, Houston, Tex. Filed Aug. 1, 1957, Ser. No. 675,661 8 Claims. (Cl. 169-2) This invention relates to fire extinguishers and more particularly to automatic fire extinguishers to be associated with high pressure gas transmission lines and prevent or extinguish the fires which usually occur upon a break in a pipeline.

Present day gas transmission lines are 30 inches and 36 inches in diameter and utilize welded seam pipe having a wall thickness as low as 0.312. Operating pressures in these lines are frequently as high as 800 to 1200 pounds per square inch. These lines run into and through cities, industrial areas, parallel to railroads, through alleys, etc. These lines are subject to corrosion, vibration, metal fatigue, and contraction. Any of these and other problems could and do cause blow-outs or line breaks.

Where a line break occurs in a gas transmission line in a rural area little damage is usually done even if a fire occurs. Where a break occurs in a highly industrialized or populated area the gas may be blown for many blocks and undoubtedly would be ignited in one of many different ways. For instance pilot lights, sparks, or the like may ignite the gas. Sparks are perhaps the greatest danger in either rural or urban areas due to blowing of rocks and other objects along the ground by the gas as it leaves the pipeline.

A transmission line packed with gas will blow for a considerable time depending upon the distance to the nearest compressor station. This blowing gas, when ignited becomes a tremendous blow torch and can cause tremendous damage.

Block valves are used in some areas for operational shut-off purposes, but are not generally located on opposite sides of highly industrialized or populated areas. Even if the block valves are present the fire danger is still tremendous as these valves will be located some distance apart and will require some time to close.

By this invention there is provided an automatic fire extinguisher which will deliver an atomized spray of fire extinguishing liquid such as water at the location of the break regardless of where it occurs in the area to be protected. This fire extinguisher functions automatically in response to conditions which are set up in the pipeline upon the occurrence of a break. The fire extinguishing fluid will reach the location of the break immediately after the break occurs and will extinguish any fire which has started. The area will also be wet down thoroughly with fire extinguishing fluid to prevent the occurrence of further fire as the line continues to blow.

It is an object of this invention to provide an automatic fire extinguisher for pipelines, particularly those which pass through congested areas.

Another object is to provide a fire extinguisher for pipelines which automatically blankets with fire extinguishing fluid the location of a break in a line, wherever it may occur, immediately after the break occurs.

Another object is to provide a plurality of fire extinguishers which upon the occurrence of a break, automatically blankets the area of a break with successive charges of fire extinguishing fluid.

Another object is to provide a the extinguisher for a pipeline which is automatically actuated upon the occurrence of a break in the line and which automatically blankets the area over which the escaping gas is being blown with fire extinguishing fluid.

Other objects, features and advantages of this invention will be apparent from the drawings, the specification and the claims.

In the drawings wherein there is shown by way of illustration one embodiment of this invention and wherein like referenced numerals indicate like parts:

FIG. 1 is a plan view of a section of pipeline employing two of the fire extinguishers of this invention;

FIG. 2 is an isometric view of a fire extinguisher constructed in accordance with this invention;

FIG. 3 is a view along the lines 3-3 of FIG. 1; and

FIG. 4 shows the manner in which a pipeline passing through a congested area will be protected by one or more of the fire extinguishers of this invention.

Referring now to the drawings the gas transmission pipeline indicated generally at 10 is protected by the fire extinguishers indicated generally at 11.

The fire extinguisher includes a tank or extinguisher supply reservoir located closely adjacent the pipeline for supplying fire extinguisher fluid thereto. This tank may be of any desired form and may be located above or below ground. Preferably, the tank is located below ground so as to not interfere with normal use of the ground surface. The tank is preferably provided by a length of pipe which may be the same diameter as the pipe of the transmission line 10. The preferred pipe tank 12 is closed at each end as shown at 13 and is laid parallel to the transmission line 10. The volume of tank 12 is preferably large enough to completely wet down the area of a break. By way of example for high pressure large diameter lines such as 30 inch pipelines it is preferred to use from 400 to 800 feet of 30 inch pipe to provide tank 12. 800 feet of 30 inch pipe would have a capacity of approximately 29,000 gallons of water. If the two extinguishers are installed in an area the volume of water to be released in the area would be approximately 58,000 gallons which would thoroughly wet down the area of a break and prevent fire.

The discharge of water from the tank should be automatic in response to the occurrence of the break. The water discharged may be triggered in any desired manner by the abnormal conditions which exist in a pipeline upon the occurrence of a break. The two most prominent abnormal conditions are increased velocity and increased pressure drop along the line. It is preferred to use the pressure drop to automatically discharge the fire extinguishing fluid from tank 12.

Pressure drop in the line may be utilized to automatically trigger discharge of fluid from tank 12 by connecting two lines 13 and 14 to the tank 12 and to the line 10 at spaced points. Thus the lines 13 and 14 will reflect the pressure drop along pipeline 10 due to a break. As a drop of approximately one pound per hundred feet of pipe is not normally possible between compressor stations in operation without a break the fire extinguisher may conveniently be triggered by a drop of, say, three to ten pounds.

The pressure drop at which it is desired to trigger the fire extinguisher will govern the height to which portions of lines 13 and 14 will extend above tank 12. Utilizing the well known physical phenomenon that differential in pressure will raise a water column approximately 27 inches per pound the portion 13a of line 13 and 14a of line 14 may be extended to the desired height to control the pressure drop at which the fire extinguisher will begin transferring fire extinguishing fluid to the pipeline 10. It will be noted from FIG. 3 that line 13 has one terminus 13b adjacent the bottom of tank 12. Thus if the line pressure drops from line 14 to line 13 the gas within the line will enter through line 14 and will force fire extinguishing fluid from the tank into the pipeline through line 13. Preferably both lines 13 and 14 have one end terminating at the bottom of tank 12 as shown in FIG. 3 to permit discharge of fire extinguishing fluid in event of a break on either side of the fire extinguisher. However it will be appreciated that one line might have its terminus at the top of the tank to permit the tank to operate in one direction only.

It will be appreciated that the diflerential in pressure will lift a column of fire extinguishing fluid to a predetermined height above the level of the fluid within the tank. Thus if the lines 13 and 14 are designed to permit the differential in pressure to just lift the fluid from the top of the tank to the height of portion 13a then as the pressure drop decreases the pressure differential might not be suflicient to drive the fire extinguishing fluid into the pipeline. To avoid any possibility of not driving all of the fire extinguishing fluid into the pipeline the height of portion 13a of line 13 as well as the similar portion 14a of line 14 may be designed to lift a column of fluid from the bottom of the tank to the height of portion 13a with a minimum diflerential which would be present in the line until the fire extinguisher is emptied. As an alternative the tank may be located all or partly above the pipeline as illustrated in FIG. 3 and the siphon action of fluid flowing between the tank and pipeline depended upon to empty the tank. Of course Where the tank is located above the pipeline and the fire extinguisher is triggered by operation of an automatic valve the fire extinguishing fluid may be withdrawn from the bottom of the tank. The illustrated form is preferred however as there are no moving parts involved which possibly might not function properly, nor are there any valves which with time could become inoperative due to valve members sticking in their seats.

The fire extinguishing fluid is preferably water but other fluids may be used if desired. Of course the design of lines 13 and 14 would be varied to accommodate fire extinguishing fluid of different density.

In the top of each tank 12 there is provided a fill valve 15. Also a vent valve 16 opens into the top of each tank 12. Lines 13 and 14 are provided with cutoff valves 17 and 18 respectively. When the tank needs filling the cut-off valves 17 and 18 are closed and fill valve 15 and vent valve 16 are opened. The tank may then be filled in any desired manner as from tank cars. After filling, the vent valve and fill valve are closed and the two valves 17 and 18 opened. The extinguisher is now in operative condition and upon a break in the line will introduce the fire extinguishing fluid into the pipeline. As the fire extingiushing fluid flows into the pipeline the high velocity gas will atomize the fluid and will carry it to the break in the form of an entrained fog. The water or other fluid will therefore be carried by the gas over the area which is blanketed with gas and this entire area will be wet down to extinguish and prevent fires.

Referring now to FIG. 4 this invention is shown in a typical application to a congested area such as an industrial area. A fire extinguisher 19 is provided for the pipeline on one side of the area and a second extinguisher 20 is provided on the other side of the area. If a break occurs in line 10 any where between the two

fire extinguishers

19 and 20 such as at 21 both

extinguishers

19 and 20 will discharge fire extinguishing fluid into the pipeline and it will be carried by gas to the break 21 to fog the area. It will be appreciated that the charges from the two fire extinguishers may reach the break in part simultaneously but will in part discharge successively to provide a continuous spray. The successive discharge from the two fire extinguishers will be more apparent if the break is closely adjacent one of the extinguishers. It will also be appreciated that the fire extinguishers could be positioned in banks of two or more on one or both sides of the congested area.

The gas within the conduits l3 and 14 will normally be stagnant and therefore there will be little or no tendency for the gas in the pipeline to absorb water from tank 12. However, if desired, a barrier may be inserted in each of these lines such as a frangible member or a barrier trap of the conventional U tube type filled with glycerin.

The foregoing disclosure and description of the invention is illustrative and explanatory thereof and various changes may be made within the scope of the appended claims without departing from the spirit of this invention.

What is claimed is:

1. A gas pipeline fire extinguisher comprising, a pipeline to be protected, a pipe for containing extinguisher fluid, said pipe closed at both ends to provide a tank and laid underground alongside the pipeline to be protected, two conduits connecting the tank to the pipeline for fluid communication at points sufliciently spaced to reflect a pressure drop along the line with abnormally high velocity flow in the line, each of said conduits having a portion positioned above the tank and at least one of the conduits terminating adjacent the bottom of the tank, the height of said portion of each of the said conduits which terminates adjacent the bottom of the tank being positioned above the normal fluid 'level within the tank by an amount which a column of extinguisher fluid will be raised by the differential in pressure between said points at which it is desired to begin injecting extinguisher fluid into the pipeline.

2. A pipeline fire extinguisher for a pipeline extending through a congested area comprising, a pair of tanks each provided by a closed end conduit laid alongside the pipeline to be protected, one tank being laid on each side of the congested area, a pair of conduits connecting each tank to the pipeline at points sufliciently spaced along the pipeline to reflect a pressure drop along the line with abnormally high velocity flow in either direction in the line, each of said conduits terminating adjacent the bottom of a tank, each of said conduits having portions positioned above the tank by an amount equal to the height of a column of water which will be supported by a pressure diiferential equal to the pressure differential between the conduits of each of said pair at which it is desired to inject Water into the pipeline.

3. A pipeline fire extinguisher system comprising, a pipeline to be protected, a tank for containing extinguisher fluid adjacent the pipeline, means connecting the tank to the pipeline and preventing flow of fluid from the tank to the pipeline while fluid flow in the pipeline is below a predetermined velocity, said means sensing pressure in said pipeline at points sufliciently spaced to reflect a predetermined pressure drop along the pipeline when fluid flow therein exceeds a predetermined normal velocity and operable in response to fluid flow in the pipeline above said predetermined normal velocity for transferring fluid from the tank to the pipeline.

4. A pipeline fire extinguisher system comprising, a pipeline to be protected, a tank for containing extinguisher fluid adjacent the pipeline, fire extinguisher fluid in said tank, means connecting the tank to the pipeline and preventing flow of fluid from the tank to the pipeline while fluid flow in the pipeline is below a predetermined velocity, said means sensing pressure in said pipeline at points sufficiently spaced to reflect a predetermined pressure drop along the pipeline when fluid flow therein exceeds a predetermined normal velocity and operable in response to fluid flow in the pipeline above said predetermined normal velocity for transferring fluid from the tank to the pipeline.

5. A pipeline fire extinguisher system comprising, a pipeline to be protected, a tank positioned alongside the pipeline, two conduits connecting the tank to the pipeline at points sufliciently spaced to reflect a predetermined pressure drop along the pipeline when fluid flow therein exceeds a predetermined normal velocity, said conduits having portions positioned above the tank, one of said conduits terminating in and adjacent the bottom of the tank, at least one of said portions positioned above said conduit terminus in the tank by a distance at least equal to a column of fire extinguisher liquid which will be supported by the pressure differential in the pipeline at said connections when fluid flow in the pipeline is flowing at said normal velocity but not more than a distance equal to the height of a column of fire extinguisher fluid which will be supported by the pressure differential in the pipeline at said connections when fluid How in the pipeline exceeds said normal velocity by a predetermined amount.

6. The system of claim 5 wherein both conduits terminate adjacent the bottom of the tank and have portions above the tank at approximately the same elevation.

7. The system of claim 5 wherein the tank is located at least in part at a higher elevation than the pipeline whereby once flow commences through said conduits such flow will continue through a siphoning action.

8. A pipeline fire extinguisher comprising, a pipeline to be protected, a tank alongside the pipeline to be protected, two conduits connecting the tank to the pipeline at points sufiiciently spaced to reflect a pressure drop along the line with a predetermined abnormally high velocity flow in the line, at least one of said conduits having a portion positioned above the tank and terminating adjacent the bottom of the tank, the height of said portion being suflicient to prevent flow of liquid from the tank to the pipeline due to the pressure differential at said points when the velocity of flow in said pipeline is not greater than a predetermined normal velocity but not enough to prevent flow of liquid from the tank due to the pressure diflierential at said points when the velocity of flow in said pipeline increases above said normal velocity to said predetermined abnormally high velocity.

References Cited in the file of this patent UNITED STATES PATENTS 1,640,839 Kliewer Aug. 30, 1927 2,141,591 Bonner Dec. 27, 1938 2,178,519 Gill Oct. 31, 1939 2,327,335 Boerner et a1 Aug. 24, 1943 2,606,690 Hansen Aug. 12, 1952 2,707,480 Klosse May 3, 1955