US2260515A - Method for extinguishing fires in bales and loosely piled materials - Google Patents

Description

Oct. 28, 1941. I H. ENSMINGER ET-AL METHOD FOR EXTINGUISHING FIRES IN BALED AND LOOSELY PILED MATERIALS 2 Sheets-Sheet 1 Filed Dec ilfilillllmg l Oct. 28, 1941. H. ENSMINGER E AL 2, 1

METHOD FOR EXTINGUISHING FIRES'IN BALED AND LOQSELY PI-LED MATERIALS Filed Dec. 14, 1958 2 Sheets-Sheet 2 atented Oct. 28, 1941 UNITED STAT ES} PATENT OFFICE METHOD FOR EXTINGUISHING FIRES IN BALED AND LOOSELY FILED MATERIALS Harry Ensminger, Chicago, and Clarence H.

Caughey, Aurora, 111., assignors to Cardox Corporation, Chicago, Ill., a corporation of Illinois Application December 14, 1938, Serial No. 245,776

2 Claims.

This invention relates to new and useful improvements in methods for extinguishing fires in baled and loosely piled materials, and relates particularly to fires which are burning beneath the surfaces of the bales or piles.

The application of a fire extinguishing liquid .to the exposed surfaces of baled or piled material, in which a deeply seated fire is burning, is a relatively ineflective way of combating the fire. If the liquid is capable of remaining in liquid form after being released to the atmosphere, it must' seep or, flow by gravity through the crevices and relatively small void spaces until it reaches the location of the fire. If the blanket.

It is the primary obie'ctof this invention to provide a method which deals with delivering a suitable fire extinguishing medium, such as liquid carbon dioxide, to the immediate location of a fire which is deeply seated in baled or loosely piled material and for effectively discharging the medium directly onto the material being consumed or so that it will expand uniformly in all directions to exclude oxygen.

In combating deeply seated fires in storage piles of coal, grain, feed. cereals, cotton, or the like, it has been found to be highly desirable to not only deliver the extinguishing medium directly to the location or the fire, but also deliver-a medium of such a' character and in such a state or condition that it will expand or travel throughout all the crevices or void spaces uniiormly in all directions at a relatively low velocity. l v

It is a further important object of the invention to provide a method for extinguishing fires which are deeply seated in storage piles of loose material by delivering directly to the location of the fire and at a relatively low velocity and pressure an extinguishing medium, such as liquid carbon dioxide, which is so conditioned that, upon being released, it will expand uniformly and relatively gradually or with a prolonged action in all directions, whereby the percentage of oxygen in the crevices and void spaces will be lowered to a point insufficient to support combustion.

In combating fires which are deeply seated in bales of cotton, rags, paper and the like, it has been found to be highly desirable to deliver the extinguishing medium directly to the central portion of the bale at a low velocity and pressure and in a highly concentrated conditio These special requirements regarding baled materials are made necessary by the fact that there is very little circulation of air'within the void spaces and the fire essentially is a smoldering one. The incandescent particles of material combine with oxygen to sustain their incandescence and it is well known that incandescent particles of material, especially carbonaceous material, have the ability of maintaining their inoandescence on appreciably lower concentrations of oxygen in the air than is required to support open combustion.

A still further important object of the invention is to provide a method for extinguishing fires which are deeply seated in baled material by delivering to the central portion of a bale an extinguishing medium, such as liquid carbon dioxide, with the delivery or discharge taking place at a very low velocity and pressure, with the medium being concentrated at the delivery zone, and with the medium properly conditioned so as to cause it to travel or expand uniformly and relatively gradually in all directions, whereby the percentage of oxygen will be reduced to a point where it will not even support incandescence.

Another object of the invention is to provide a method for applying liquid carbon dioxide, or other compressible gases or liquids, which are especially adapted for extinguishing fires that are deeply seated in baled or piled material and which are designed to effect discharge of the liquid in such a manner as' to prevent freezing up of this specification and in which like numerals are employed to designate like partsthroughout the same, v

Figure 1 is'a diagrammatic view illustrating a method suitable for extinguishing a fire which is burning beneath the surface of a storage pile of loose material,

of discharging a. fire extinguishing medium thereinto,

Figure 6 is a side elevational view of the form of applicator disclosed in Fig. 5,

Figure '7 is a transverse sectional view taken on line 1-1 of Fig. 6, and

Figure 8 is a fragmentary longitudinal sectional view of the applicator disclosed in detail in Figs. 6 and 7.

In the drawings, wherein for the purpose of illustration are shown the preferred embodiments of this invention, and particularly referring to Fig. 1, extensive experiments have shown that liquid carbon dioxide is an extremely effective fire extinguishing medium in combating either surface or deeply seated fires which are consuming baled materials or loose materials which are arranged in storage piles. Liquid carbon dioxide when discharged into the atmosphere and permitted to suddenly expand, will be converted into a mixture of gas and snow. It has been determined that the percentage of snow produced by the sudden expansion of liquid carbon dioxide can be materially increased by lowering the discharge temperature of the liquid carbon dioxide. In fact, the percentage of snow will increase in proportion to the lowering of the discharge temperature of the liquid carbon dioxide. For example, carbon dioxide gas released at what will be termed atmospheric temperature, or 70 F., theoretically will produce 29% snow, while liquid carbon dioxide released to the atmosphere at 0 F. produces 50% snow.

In combating fires which are deeply seated in storage piles of loose material, such as coal, feed. grain, or the like, it is essential that the extinguishing medium be of a character which will expand uniformly in all directions. Carbon dioxide gas is very suitable for this purpose It, also, is essential that the fire extinguishing medium be discharged at a sufllciently low velocity and pressure to preclude the possibility of the medium expanding or spreading with a sufficient velocity to blow vent holes or fiues in the material through which the expanding medium may flow to the surface of the pile without being uniformly distributed through the void spaces in the pile. The discharge velocity and pressure, of course, may be varied depending upon the size of the material stored in the pile.

Of course, it is possible to deliver nothing but carbon dioxide gas to the point of discharge in the pile of burning material. It, also, is possible to deliver liquid carbon dioxide from a source of supply where the carbon dioxide is maintained at or subject to temperature variations; 1. e., where the liquid carbon dioxide is stored at atmospheric or room temperature. With both of these types of discharge, however, the vapor pressure of the carbon dioxide necessarily is extremely high and the possibility of forming blow holes or flues in the material is great. If the liquid carbon dioxide is delivered to the point of discharge at a subatmospheric temperature, for example, 32 F. or lower, the pressure of the discharge is considerably lower and the medium may be discharged at a lower velocity. Furthermore, the discharged low temperature liquid carbon dioxide will be converted into a much higher percentage of snow which will be static until it is converted to gas as the result of sublimation. The discharge of liquid carbon dioxide at a subatmospheric temperature, therefore, assures a uniform distribution or expansion of carbon dioxide gas in all directions at a suitable low velocity and pressure while the sublimation of the carbon dioxide snow brings about a prolonged or delayed delivery of gas even after actual discharge of the liquid carbon dioxide is discontinued. This delayed or prolonged release of gas is very helpful in preventing refiash. Naturally, the delivery of a fire extinguishing medium directly to the location of the fire or into the combustion zone of the fire results in raising the temperature of the medium. Therefore, the lower the temperature of the liquid carbon dioxide at desired quantity of liquid carbon dioxide. Preferably, the carbon dioxide is charged into the container ID at a suitable subatmospheric temperature. The charging temperature, however,

may be higher or lower than the temperature at which it is desired to maintain the liquid carbon dioxide during the storage period. A conventional commercial or domestic refrigerating unit II is associated with the insulated storage container i0 and is connected to a cooling coil, or the like. not shown, within the container by means of piping II. This conventional refrigerating unit ll functions to maintain the liquid carbon dioxidestored in the container It at any desired subatmospheric temperature.

To effect discharge of this low temperature carbon dioxide liquid to the location of the fire, a discharge pipe l3 communicates with the insulated container iii. A flexible tube or hose II is coupled at ii to the pipe". A supply control valve l6 may be placed at a suitable point 5 in the pipe l3.

Fig. 4 discloses the flexible hose or tubing ll as being coupled at H to a distributing manifold l8 with a valve l9 arranged to control com- I munication between this manifold and the tube or hose ll. Coupled to the opposite ends of the manifold i8 is a pair of applicators 20. It is to be understood that these applicators may be of any desired length and that either one or more than two applicators may be suitably connected to the delivery hose or tubing i4 instead of the two applicators disclosed in Fig. 4.

Figs. 2 and 3 disclose in detail the construction of each applicator 20. The applicator consists of a suitable-length of rigid pipe or tubing of any end of the-tubular body 2! by brazing or welding, as at 25, or, if preferred, by casting the plug in the end of the said body.

To efiectdischarge of the fire extinguishing medium, the body 2| is provided with a circumferential series of ports orslots 26. Fig. 3 clearly illustrates these ports or slots are being tangentiallyarranged with respect to the circular bore 21 of the body. Fig. 3 also illustrates the tangential type of discharge of the medium. As stated above, the character of the material stored in the pile being consumed by the fire will determine the pressure and velocity at which the medium is to be discharged. The quantity of carbon dioxide discharged per unit of time may be varied by varying the total area of the discharge ports or slots 26. It'has been determined that the total area of these discharge ports may vary from 25% to 70% of the total cross sectional area of the bore 21.

In discharging liquid carbon dioxide to the atmosphere, refrigeration naturally occurs and for that reason the discharge apparatus must be of a proper construction to preclude the possibility of clogging or freezing up of the ports. The

from a source of supply-of subatmospheric temperatured'liquid carbon dioxide.

i be employed for connecting the plug to the tuburectangular type of ports 23 produces a fiat and very emcient character of discharge of the extinguishing medium and this design of discharge port precludes the possibility of freeze-ups or clogging due to refrigeration during discharge. Sufiicient follow-up pressure should be maintained in the bore of the tubular body 2| to insure lar body. A spiral series of small circular ports or apertures 3'5 is formed in the tubular body. Figs. '1 and 8 clearly disclose these apertures as being countersunk at 33 or on their downstream side to form thin edged entrance openings 38. This removal of metal from the downstream ends or sides of the ports precludes the possibility of rapid refrigeration which would cause freezing or plugging up of the ports. The total combined areas of allof these discharge ports 31 may be varied as desired to provide a suitable low velocity and low pressure type of discharge. It has been found that most efllcient operation will be provided if the total combined areas of the discharge ports ranges from 25%.to 75% of the total cross sectional area of the bore of the tubular body 34.

the delivery ofliquid carbon dioxide to the outer or atmospheric ends 23 of the ports. Expansion of the liquid carbon dioidde then will occur beyond the outer ends of the ports and the metal surrounding these ports is of such shape that the extreme cold, due to refrigeration, is conducted in the direction indicated by the arrow- 30 and freeze-ups are prevented.

It will be noted by inspecting Fig. 2 that the discharge ports "are spaced inwardly from the outer end of the body 2i 9. sufllcient distance to provide a pocket 3| between the ports and the plug as. This pocket functions to receive any metal scale or other foreign matter which is delivered to the applicator in the extinguishing medium and thus willavoid clogging of the discharge ports.

Fig. 1 discloses an applicator 20 after being inserted in thestorage pile 3| for the purpose of delivering the fire extinguishing medium to the location of the deeply seated fire. The sharpened or pointed plug 24 makes possible this penetration of the applicator.

Fig. 5 discloses a bale 32 of cotton, rags, paper, or the like. It has been determined that the best way to combat a fire burning in baled material is to deliver the extinguishing medium to the central portion of the bale so that it may uniformly expand in all directions. Due to the scarcity of oxygen in the tightly packed baled material, the fire essentially is a smoldering one. To extinguish such a fire, it is necessary for the medium to reduce the concentration of oxygen to such a low point that it will not sustain incandescence. It, furthermore, is essential that the extinguishing medium be delivered to the central portion of the bale at slower velocity and pressure than is suitable for extinguishing fires in loosely piled material.- For that reason, Fig. 5 discloses a flexible hose or tubing l4 which is intended to receive a supply of carbon dioxide in the same manner as that illustrated in Fig. 1; i. e.,

Fig. 6 clearly illustrates the flexible hose or tubing M as being coupled to a manually con- I trolled valve casing 40. This valve casing is connected by a nipple iii to an internally threaded boss 42 formed on the tubular body 34.

To enable the applicator to be driven into the central portion of the bale 32, a solid-round driving or striking head 43 is secured to the inner extremity of the tubular body 34 by welding, brazing, or the like 44. A handle bar 45 extends through the striking ball or head 43 and is welded in place at 48. This cross handle 43 may be employed for extracting the applicator from the bale 32 by twisting or turning the applicator to loosen it Although it has been determined to be highly desirable to employ liquid carbon dioxide at a suitable subatmospheric temperature for extinguishing deeply seated fires in baled or piled materials, it will be appreciated that the ap plicators disclosed and described herein also may be employed for discharging other compressible ases or liquids as well as carbon dioxide and that the extinguishing medium may be supplied to the applicators at atmospheric or room temperature.

It is to be understood that the forms of this invention herewith shown and described are to be taken as preferred examples of the same, and that various changes in the shape, size, and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the subloined claims.

Having thus described the invention, we claim:

1. A method of extinguishing fires which are deeply seated relative to the exposed surface of the combustible material being consumed, comprising conducting carbon dioxide as a liquid at r 'a sub-atmospheric temperature and its corresponding low vapor pressure to a location adiacent or approximately within the combustion zone of the fire, allowing said liquid carbon dioxide to suddenly expand at said location to form a mixture of vapors and snow, and discharging said mixture at a velocity and pressure which is sufilciently low toprevent the formation of fines in the material through which the carbon dioxide vapors of said mixture and those resulting from sublimation of the snow may directly escape, said vapors thereby being compelled to expand uniformly in all directions to reduce the oxygen concentration in the burning material below that which is necessary to support combustion.

2. A method of extinguishing tires which are deeply seated relative to the exposed surface of the combustible material being consumed, comprising maintaining a supply of liquid carbon dioxide at a sub-atmospheric temperature and its corresponding low vapor pressure, conducting said carbon dioxide as a liquid at a sub-atmospheric temperature and pressure to a location adjacent or approximately within the combustion zone of the fire, allowing said liquid carbon dioxide to suddenly expand at said location to form a mixture of vapor and snow, and discharging said mixture in a plurality of radial directions at a velocity and pressure which is sumciently low to prevent the formation of fines in the material through which the carbon dioxide vapors of said mixture and those resulting from sublimation of the snow may directly escape, said vapors thereby being compelled to expand uniformly in all direction throughout the void spaces provided by the combustible mixture to reduce the oxygen concentration below that which is necessary to support combustion.

- CLARENCE H. CAUGHEY.

HARRY ENSMINGER.

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