US3505957A - Apparatus for dissemination of materials by implosion - Google Patents

Description

April 1970 E. J. TICHAUER ETAL 3,505,957

APPARATUS FOR DISSEMINATION OF MATERIALS BY IMPLOSION Fiied Nov. 20, 1967 v 2 Sheets-Sheet 1 F'Go I l6 Z9 INVENTORS.

47 ae/vssr .1 7701/41/52 smzvusr 4'. H11 #55 BY 0941550708 C OLE/V April 14, 1970 E- J. TICHAUER ETAL 3,505,957

APPARATUS FOR DISSEMINATION OF MATERIALS BY IMPLOSION Filed Nov. 20,1967 2 Sheets-Sheet 2 Patented Apr. 14, 1970 3,505,957 APPARATUS FOR DISSEMINATION OF MATERIALS BY IMPLOSION Ernest J. Tichauer, Santa Ana, Stanley G. Hughes, Palos Verdes, and Lambertus Coolen, Los Angeles, Calif., assignors, by mesne assignments, to the United States of America as represented by the Secretary of the Air Force Filed Nov. 20, 1967, Ser. No. 684,353 Int. Cl. F42]: 25/14 US. Cl. 102-6 1 Claim ABSTRACT OF THE DISCLOSURE Wide dispersal of material is effected by detonating simultaneously a pair of spaced explosive charges adjacent to the material, one of the explosive charges being positioned above the material and the other smaller explosive charge being below the material.

In the conventional explosive dissemination of material, a single explosive charge is usually employed to break up the material and hurl outwardly the resultant particles thereof. Ordinarily, the force of the explosion propels particles of material in all directions and a considerable amount' of the total explosive force is consumed in hurling material upwardly. Consequently, only a fraction of the explosive force is effectively used to disseminate material laterally and the ground area over which the material sprays is often relatively small.

Where a single explosive charge is used in disseminating a flammable liquid fuel, such as a hydrocarbon fuel employed in fire bombs, the force of the explosion often creates an almost spherical cloud of fuel before ignition is achieved. Since the ensuing flame front passes quickly across the entire fuel cloud, the bulk of fuel is consumed in a ball of fire before the droplets of fuel can settle. In most military applications, however, it is preferred to disperse the fuel over a much larger area and effect combustion of the fuel nearer the ground.

Attempts have been made to effect wider dispersal of liquid fuels by simultaneously detonating a pair of balanced explosive charges placed above and below the container of fuel. By imploding the fuel in this manner, a hemispherical cloud of fuel is formed which also burns as a fire ball before settling of fuel occurs. Although combustion of the total mass of fuel occurs slightly nearer the ground when two such explosive charges are used, the ground area over which the fuel spreads is not substantially greater than when only a single charge of the same total weight of explosive is employed.

It is therefore a principal object of the invention to provide an improved process of effectively using explosives to disseminate materials.

Another object is to provide in a bomb structure an improved arrangement of explosives for disseminating materials by implosion.

Yet another object is to provide an improved fire bomb for creating a low lying cloud of liquid fuel over a relatively large area.

Still another object is to provide an improved bomb for the dissemination of solid materials over a wide area.

These and other objects and advantages of the invention will become apparent upon reference to the following description, drawings and claim appended hereto.

To attain the foregoing objects, it has been surprisingly found that the simultaneous detonation of a pair of explosive charges, one above and the other below the material, produces wide dissemination of the material when the top explosive charge is at least 1.1 times greater than the bottom charge.

In practice, the weight ratio of the top explosive charge to thebottom charge is from about 1.1 to 1.7, preferably from about 1.2 to 1.5, more preferably from about 1.3 to 1.4. The charges can be in the form of relatively thin plates or discs which cover both the upper and lower surfaces of the container holding the material to be dispersed. Although an explosive charge of any shape can be used, it is preferred to employ symmetrical charges of uniform thickness. These explosive charges can be mechanically affixed to either the inside or the outside of the container for the material, or else, bonded thereto by the use of a conventional adhesive.

Among the various materials which advantageously can be disseminated according to the present invention are relatively frangible solids such as naphthylene, acetyl benzyl peroxide, bismuth ethyl chloride, coal, as well as non-frangible solid materials such as parafiins, magnesium, etc. Since the force of the explosion breaks up the frangible solids as they are being dispersed, any desired size of such dispersed particles can be effected by merely regulating the initial particle size and the size of the explosive charges.

The process of the present invention is particularly suitable for the dissemination of flammable liquid fuels such as benzene, alcohol, kerosene, jet fuel, gasoline and other similar petroleum hydrocarbons. Where such liquid fuels are used as in a fire bomb, they preferably contain jelling agents such as polystyrene and isobutyl methacrylate as well as metal soaps such a aluminum alkyls and aluminum arylalkyls.

Suitable explosives for the use herein can comprise mixtures of, for example, trinitrotoluene, ammonium picrate, lead azide, pentaerythritol tetranitrate, cyclotrimethylene, trinitramine and other of the explosive compositions disclosed in US. Patent 2,999,793 and 2,992,- 087, the disclosures of which are incorporated herein by reference. These explosives can be advantageously blended with an elastorneric material such as poly isobutylene or polystyrene and/or a wax to yield an explosive composition which is more easily cut, bent, and otherwise formed into the desired shape.

With the fire bomb of the present invention, the particle size of dispersed fuel which affects the duration of burning and the flame temperature can be controlled by regulating the charge to fuel ratio, i.e., the weight ratio of explosive to combustible fuel. In this way, the variation in the amount of explosive can be tailored to provide a bomb for various intended purposes. In most applications, the charge to fuel ratio ranges between about .04 to .15, preferably between about .05 to .12.

To effect optimum dispersal of the liquid fuel, the fuel container is preferably formed of relatively light gauge material which can be easily ruptured. Suitable materials for the container are, for example, rolled aluminum or steel sheet. In a typical bomb, for example, an explosive disc of pentaerythritol tetranitrate .500 inch in thickness is used with a bomb casing of aluminum .060 inch thick. Where an explosive disc is used on the outside of the casing, it is preferred to use a protective outer skin of thin gauge aluminum sheet. In case the explosive sheet or disc is to be situated on the inside of the bomb casing, an interliner of thin gauge sheet metal or synthetic resin sheet can be used as a protective liner.

Although the liquid fuel container can, in general, be of any desired shape, it is preferred to use a fuel tank tailored in length to best suit the particular application. With the generally right circular fuel tank, optimum radial dissemination of the fuel is obtained using a ratio of length to diameter of about 1:1. In cases where a large fire ball is desired, other shapes can be employed such as a spherical fuel tank.

Bombs constructed according to the present invention can also be employed to disperse various of the liquid chemical agents which produce a toxic or irritating physiological effect, a smoke screen, an incendiary action other than a fire bomb effect, or a combination of these effects.

The invention will be illustrated further in the accompanying drawings in which:

FIG. 1 is a perspective view of the several components making up a fire bomb, the principal components being shown in their relative position;

FIG. 2 is a fragmentary view taken along line 22 of FIG. 1, showing an enlarged cross section of one of the fuel expansion chambers;

FIG. 3 is a top view of the fire bomb of FIG. 1, illustrating the arrangement of the three expansion chambers and the booster assembly shown in dotted lines;

FIG. 4 is a side elevational view of the assembled fire bomb of FIG. 1, showing in partial broken sections the fuze and the booster assemblies connected thereto;

FIG. 5 is a fragmentary view taken along line 55 of FIG. 3, showing an enlarged cross section of the fuel loading port;

FIG. 6 is a fragmentary view taken along line 66 of of FIG. 4, showing an enlarged cross section of the fuze assembly;

FIG. 7 is a fragmentary view taken along line 77 of FIG. 4, showing the propagating cord sleeve;

FIG. 8 is a fragmentary view taken along line 8-8 of FIG. 4, showing in an enlarged cross section the connection betwen the skirt and the lower stabilizer plate.

Referring now to the drawings, the bomb structure shown in FIG. 1 comprises a generally cylindrical fuel tank assembly 5 with a plurality of expansion chambers 11 connected thereto, an outer housing or skirt 21, a top protective cover assembly 33, a resilient cushion 43, and a bottom counterweight or stabilizer plate 47. The fuel tank assembly 5 consists of a relatively thin walled cylindrical metal shell 6 with flanged and reinforced flat heads 7 welded at each end thereof (FIG. 2).

Three pairs of expansion fittings, a bottom fitting 12 and a top fitting 13 are Welded to the cylindrical tank shell, each pair of such fittings being connected by an elastic expansion tube 11 formed from a material inert to the fuel in the tank. The tube 11 can be advantageously formed from flexible polymers or copolymers of polyvinyl chloride, and other similar elastic synthetic resins. Clamps 15 are secured about the tube at each end thereof to efiect a liquid seal between the tube and the expansion fitting. Each of the top fittings 13 are provided with a threaded vent screw 16, an associated sealing washer 17, the vent screw 16 being removed to permit escape of entrapped air when the tank is being filled. The flow of both fuel and gases between tank 5 and expansion tubes 11 is facilitated by passage 18 formed in expansion fittings 12, 13.

Fuel is introduced into tanks through fill fitting 19 which can be closed by pipe threaded filling plug 20 (FIGS. 1, 3, and 5). Should the ambient temperature rise causing the volume of fuel to increase because of the change in density, fuel in the filled fuel tank flows through passage 18 into the flexible tube 11 which expands to accommodate the increase in fuel volume. Due to the resistance of the elastic tubes to such dilation, the internal pressure of fuel rises which can cause slight bulging deformation of flat heads 7.

The skirt 21 comprises a relatively thin sheet metal housing, square in cross section having rounded corners, the four sides of the skirt being tangent but not mechanically attached to the cylindrical fuel tank 5. The skirt is sufliciently longer than the fuel tank to permit installation of the cover assembly 33, cushion 43, and base plate 47 (see FIGS. 1 and 4).

An impact mechanical fuze can be screwed into a flanged and internally threaded fuze seat 22 which can be attached to the skirt 21 at about the mid length of the skirt below filling fitting 19. Although any of the conventional impact type mechanical fuzes can be used, it is preferred to employ an omnidirectional fuze of the delayed arming and instant acting type. Attached to the inner end of the fuze seat 22 is a lead out assembly 23 which consists of a disc of sheet type explosive material 24 in close proximity to the output end of the fuze 25 and the respective ends of two equal lengths of detonating cord 26.

The other ends of the detonating cords 26 are connected to booster assemblies 27, 28 attached, respectively, to the upper and lower explosive charges 29, 30 (FIGS. 2, 4, and 5 These booster assemblies shown in dashed lines in FIG. 3 comprise a detonator'and booster charge 31 encased within a plastic housing 32. In a preferred embodiment shown in FIG. 4, relatively thin cushion pads 34, 34 (FIGS, 2 and 4) lie on the upper and lower surfaces of top explosive charge 29.

Intermediate the bottom head 7 of tank 5 and the lower explosive charge 30 is another cushion pad 37, the lower surface of charge 30 resting on a relatively thick resilient cushion 43. A groove 35 is formed in an upper surface of cushion 43 for the lower detonating cord 26, and a hole 44 is cut in this cushion to accommodate booster assembly 28. A conventional adhesive can advantageously be used to secure the assemblies 27, 28 to the respective explosive charges. A protective sleeve 36 surrounds the detonanng cord 26 where it bends around the corners of tank 5 (FIG. 7).

A relative heavy metal base plate 47 is secured to the lower end of the skirt 21 by means of countersunk, fiat headed machine screw 49 (FIG. 8). Because of the relative thickness of the skirt, the skirt metal is dimpled, or swaged, into the oversized countersunk bore in the base plate, to provide a flush exterior.

From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of this invention, and without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions. Consequently, such changes and modifications are properly, equitably, and intended to be, within the full range of equivalency of the following claim.

What we claim is:

1. A device for disseminating flammable liquid materials by implosion which comprises:

a container for the flammable liquid to be disseminated;

an explosive charge on both the top and bottom of said container, the charge above the container being at least 1.1 times larger than the charge below the container;

at least one elastic expansion tube connected to and communicating with said container to permit the flow of said flammable liquid from said container into the expansion tube, thereby preventing rupture of said contain-er when said flammable liquid fuel expands;

a fuze to initiate simultaneous detonation of both explosive charges whereby to redirect the upward blast force and eifect wide lateral dispersion of said flammable liquid materials.

References Cited UNITED STATES PATENTS 1,287,372 12/l9l8 McGaw 102-66 2,535,309 12/1950 Mari 102-34.4- 2,586,801 2/1952 Epler et al. 1026 3,382,800 5/1968 Biggs 1026 SAMUEL W. ENGLE, Primary Examiner US. Cl. X.R. 10266,

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