US3369608A - Discharge horn for liquefied fire extinguishing agent - Google Patents

Description

Feb. 20, 1968 w. M. HAESSLER .ETAL

SHING AGENT DISCHARGE HORN FOR LIQUEFIED FIRE EXTINGUI Filed April 18, 1966 INVENTORS. #4555451? Mz 75? M T ORNEY Unite States Patent 3,369,608 DISCHARGE BURN FOR LIQUEFIED FIRE EXTINGUISHING AGENT Walter M. Haessler, Chatharn, and Ronald M. Taylor, Madison, N.J., assignors to The Fyr-Fyter Company, New York, N .Y.

Filed Apr. 18, 1966, Ser. No. 543,192 Claims. (Cl. 16911) ABSTRACT OF THE DISCLOSURE A discharge nozzle for fire extinguishing fluid having a housing with a discharge horn projecting from the housing. On the closed end of the discharge horn is positioned a plate having an outwardly turned edge which may be serrated. An inlet pipe is positioned in front of the said plate, the inlet pipe being apertured to provide an orifice on its side facing said plate.

This invention relates to an improved method and apparatus for discharging fire extinguishing medium.

In using carbon dioxide as a fire extinguishing agent it is generally discharged under pressure from containers to a fire. It is important that the velocity of the discharge stream be reduced so that the issuing stream of carbon dioxide does not entrain air which would be carried to the fire. Furthermore, the effectiveness of carbon dioxide as a fire extinguishing agent is increased by convetting a large portion of the discharged fluid into carbon dioxide snow.

Early in the art a discharge device used extensively was a horn shaped member with an orifice at its narrow end. The horn served as a shield for the nozzle to prevent the entrainment of air until the velocity of the flow had been reduced to the extent that a negligible amount of air was entrained. Further, the back pressure in the horn resulted in the formation of a satisfactory amount of carbon dioxide snow. The discharge which issued from the horn was of a considerably larger diameter and more greatly reduced in velocity than the discharge from the orifice. Such discharge horns have been satisfactory excepting that they are cumbersome because of the length and size of horn required for large capacity discharges of carbon dioxide.

In an attempt to overcome the disadvantage of the long horn other constructions have been proposed such as that shown in Scott E. Allen Patent 1,993,696. In this construction a batfle member was placed ahead of the orifice so as to reduce the velocity of the discharge. In order to provide space for the discharge of the carbon dioxide around the baflie member the back or closed end of the horn was made of increased diameter.

Another construction proposed as an improvement on the Allen patent was Kucher Patent 2,547,018 in which the baflle member was made of an inverted cone and a pipe was provided from the orifice directed at the apex of the cone. The gas flow thus was around the discharge pipe and out of the wide mouth of the cone into the discharge horn of the same diameter throughout. This construction was an improvement over the Allen construction in that there was a heat exchange relationship between the expanding gas and the unexpanded gas by means of the tube so that there was believed to be a somewhat greater carbon dioxide snow production. However, under intermittent operation, in some constructions there was some clogging from carbon dioxide snow.

The present invention aims to provide an improved method and apparatus for discharging fire extinguishing medium.

In accordance with the invention a method and apparatus are provided in which the supply pipe is attached to the horn adjacent the closed end and at the side thereof. The expanded fluid is reversed in direction after discharge through the orifice, a portion of the expanded fluid being directed back over the supply pipe and the extremely cold first issuing gas, the remainder of the expanded gas being directed back outwardly over said first portion.

The construction in accordance with the invention is advantageous in that the distance required by the discharge pipe and the horn is shorter than that heretofore required.

Another object of the invention is to provide an improved method for discharging fire extinguishing medium which does not cause carbon dioxide snow clogging of the discharge nozzle even under intermittent operation.

Another object of the invention is to provide an improved apparatus for discharging fire extinguishing medium which is simple and economical in manufacture, efiicient in operation, and durable in use.

Other objects and advantages of the invention will be apparent from the following description and from the accompanying drawing which shows, by way of example, an embodiment of the invention.

In the drawing:

FIGURE 1 is a vertical cross sectional view of the discharge nozzle in accordance with the invention.

FIGURE 2 is an end view of the construction of FIG- URE l as viewed in the direction of the arrows 2-2.

Referring .to the drawing there is shown in FIGURE 1 a vertical cross sectional view of a discharge nozzle 1 in accordance with the invention and including a housing 2, an inlet pipe or tube 3 and a discharge horn 4. A deflector member 5 provides first deflecting means 6 and second deflecting means 7. The housing 2 may have its outer surface made of flattened surfaces for engagement by a wrench. A passage 8 extends through the housing 2. The passage 8 is reduced in size at one end as indicated at 9 and of increased diameter adjacent thereto to provide a shoulder it The passage 8 outwardly of the shoulder It is still further increased in diameter as indicated at 11 and made with a threaded surface 12 for attachment to a piping system.

The inner end of the housing 2 is turned over as indicated at 13 to provide means for firmly holding the discharge horn 4 in position. Further, if desired, a weld may be made as indicated at 14. The inlet pipe 3 is provided with an enlarged end 15 adapted to abut against the shoulder 19. A hole or other suitable marking means may be made as indicated at 16 to provide visual indication of the proper position of the inlet pipe 3 as will appear later. The inlet pipe 3 is retained in position in the housing 2 by a force fit between its enlarged end 15 and the adjacent inner wall 11 of the housing 2. As may be seen from the drawing the inlet pipe 3 is spaced from the circular plate or deflector member 5 by a distance less than the outer diameter of said inlet pipe.

Orifice means 29 is provided on the side Wall of the inlet pipe 3 at a position along the length of the pipe centrally of the discharge horn 4, and in line with the marking hole 16. The inlet pipe 3 is provided with a closed end 21, the pipe extending beyond the orifice 20 to provide a space 22 wherein may be entrapped dust or particles which may be carried with the gas and which might interfere with the flow of carbon dioxide through the orifice 20.

The discharge horn 4 is provided with a closed end wall 25 and an open end 26. The diameter of the open end 26 is preferably somewhat larger than the diameter of the closed end 25. The drawing is quite accurate with respect to the size and proportions of a working model.

The deflector member 5 is preferably formed of a circular plate forming the first deflecting means 6 having its edge turned out approximately at right angles to the plane of the plate 6 as indicated at 27 forming the second deflecting means ,7. The turned out edge 27 may be serrated so as to form notches 29 and teeth 30. Generally the base width of the notches 29 of the serrated edge 27 is greater than the base width of the teeth 30. In alternative constructions, for example, if the discharge horn 4 is reduced in size while the orifice and supply tube are maintained at the same size, it may be found advantageous to omit alternative teeth 30. The deflector member 5 may be secured in position against the end wall 25 by rivets 31 and 32., In an alternative construction the deflector member 5 might be made of a section of cylinder welded or otherwise suitably attached to the end wall 25 in which event the first deflecting means would be provided.

by the inner surface of the end wall 25. In assembling the nozzle 1, the marking hole 16 of the inlet pipe 3 enlarged end is placed towards the end Wall there by assuring that the orifice 20wil1 be properly positioned opposite the first deflecting means 6.

In testing commercial constructions in accordance with the invention it has been found that the spacing between the orifice and the spreader should be maintained rather closely to the proportions shown in the drawing even though the diameter of the nozzle is varied to provide different rates of discharge. While the inlet pipe 3 might be terminated just shortly after the orifice 20 it is preferable that it be extended as shown.

In practicing the method in accordance with the invention a fire extinguishing medium liquefied under pressure is discharged through the orifice 20 thereby allowing the fluid to expand while it is directed to impinge against the center of the deflecting means 6 so that the fluid is radially dispersed at practically right angles to its issuing direction. A portion of the dispersed fluid impinges against the turned out edge 27 and the teeth 30 which provide a second deflecting means causing a first portion of the radially dispersed expanded fluid to flow back over itself and over the inlet pipe 3 in a heat exchange relationship, the remainder of the radially dispersed expanded fluid being directed outwardly by the discharge horn 4. The issuing expanded gas and carbon dioxide snow issuesat a uniform rate from, the open end 26 of the horn 4.

While the invention has been described and illustrated with reference to a specific embodiment thereof, it will be understood that other embodiments may be resorted to without departing from the invention. For example, the method of the invention might be practiced by the use of a construction in which the inlet pipe is arranged to enter through the open end of the discharge horn, in which event the orifice would be positioned in the end of the inlet pipe. Therefore, the form of the invention set out above should be considered as illustrative and not as limiting the scope of the following claims.

We claim:

1. A discharge nozzle for fire extinguishing fluid liquefied under pressure comprising a housing having an inlet, an inlet tube carried by said housing at said inlet,

discharge orifice means being an aperture through the turned approximately at right angles to the plane of the plate, said plate located on the end wall of said discharge horn and spaced from said orifice, means and positioned at approximately right angles thereto.

2. A discharge nozzle according to claim 1 in which the inlet tube is positioned with its axis parallel to the plane of said circular plate.

3. A discharge nozzle according to claim 1 in which said inlet tube is spaced from said circular plate by a distance less than the outer diameter of said inlet tube.

4. A discharge nozzle according to claim 1 in which said inlet tube extends beyond its orifice so that the end wall of said tube is positioned outwardly of the edge of said circular plate.

5. A discharge nozzle according to claim 1 in which said turned edge of said plate is serrated.

References Cited UNITED STATES PATENTS M. HENSON WOOD, JR., Primary Examiner.

VAN C. \UILKS, Assistant Examiner.

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