Produced by Gerard Arthus, David Gutierrez and the Online
Distributed Proofreading Team at https://www.pgdp.net








US Patent 4,293,314: Gelled Fuel-Air Explosive




    United States Patent [19]                [11]     4,293,314

    Stull                                    [45]  Oct. 6, 1981


    [54]  GELLED FUEL-AIR EXPLOSIVE METHOD

    [75]  Inventor:    Bertram O. Stull, Ridgecrest, Calif.

    [73]  Assignee:    The United States of America as
                       represented by the Secretary of the
                       Navy, Washington, D.C.

    [21]  Appl. No.:   111,453

    [22]  Filed:   Jan. 11, 1980

    [51]  Int. Cl.^3 ................................ C10L 7/00

    [52]  U.S. Cl. ............................ 44/7 A; 44/7 R;
                                        44/7 D; 102/90; 102/363

    [58]  Field of Search ................ 102/90; 44/7 R, 7 E,
                                                    44/7 D, 7 A

    [56]  References Cited

          U.S. PATENT DOCUMENTS

          3,539,311  11/1970  Cohen et al. ............. 44/7 A
          3,634,157   1/1972  Batson ................... 44/7 E
          3,685,453   8/1972  Hawrick .................. 102/90
          3,730,093   5/1973  Cummings ................. 102/90
          3,795,556   3/1974  Sippel et al. ............ 44/7 E
          3,955,509   3/1976  Carlsen .................. 102/90
          3,994,696  11/1976  Adicoff .................. 44/7 A
          4,157,928   6/1979  Falterman et al. ......... 102/90

    _Primary Examiner_--Edward A. Miller

    _Attorney, Agent, or Firm_--R. S. Sciascia; W. Thom
    Skeer; Lloyd E. K. Pohl


    [57] ABSTRACT

    1,2-Butylene oxide as a fuel for a fuel air explosive
    weapon. The oxide may be used either as a pure liquid
    or gelled with a gelling agent such as silicon dioxide,
    particulate carbon or aluminum octoate.

    3 Claims, No Drawings




    GELLED FUEL-AIR EXPLOSIVE METHOD


    BACKGROUND OF THE INVENTION

    1. Field of the Invention                                      5

    This invention relates to fuels for fuel air explosive
    weapons. More particularly, this invention relates to a
    method for causing an explosion comprising the steps of
    dispersing a cloud of liquid fuel in the air and detonating
    the cloud wherein the cloud is composed of particles of       10
    gelled or ungelled 1,2-butylene oxide.

    1. Description of the Prior Art

    Fuel air explosive weapons are now well known. A
    typical example of one is depicted in U.S. Pat. No.
    3,955,509 which was issued to Gary A. Carlson on May          15
    11, 1976.

    Fuel air explosive weapons may be described as devices
    which, upon activation, cause liquid fuel particles
    to be dispersed in the form of a detonable cloud in the
    air and then detonate the cloud.                              20

    A number of fuels have been used in fuel air explosive
    weapons. Among these are ethylene oxide and propylene
    oxide. Because of the ease with which is cloud of
    ethylene oxide or propylene oxide can be detonated,
    these two materials are the most commonly used. However,      25
    these fuels have certain drawbacks.

    One drawback, common to both ethylene oxide and propylene
    oxide, is toxicity. Both materials are highly toxic. A
    concentration of 50 parts per million of ethylene oxide       30
    in the air may have harmful effects on one breathing the
    air for about 8 hours. Propylene oxide is less toxic than
    ethylene oxide but is still highly toxic. A concentration
    of 100 parts per million of propylene oxide breathed for
    about 8 hours may have undesirable effects. Naturally,
    when fuel air explosive devices are stored in a confined      35
    area such as aboard a ship, exposure for 8 hours is not
    unusual.

    Another drawback common to ethylene oxide and propylene
    oxide is the fact that both have relatively low boiling       40
    points, 10.4° C. and 34.2° C. respectively. This makes
    the two difficult to handle in loading operations.
    High vapor pressures also contribute to difficulty in
    handling.

    A drawback particularly associated with ethylene oxide        45
    is its tendency to polymerize during storage. Left
    alone in a fuel air explosive weapon or other container,
    ethylene oxide tends to self polymerize. The polymerized
    material is unsuitable for use as a fuel for a fuel air
    explosive device. Unpolymerized ethylene oxide, on the        50
    other hand is highly desirable as a fuel insofar as
    detonability is concerned. Clouds containing from as
    little as 3 up to as much as 100 percent by volume of
    ethylene oxide are detonable. The detonation limits of
    propylene oxide, on the other hand, range from about
    3.1 to about 27.5 percent by volume.                          55


    SUMMARY OF THE INVENTION

    It has now been found that 1,2-butylene oxide, when
    used as a fuel for fuel air explosive devices, exhibits
    marked superiority over either ethylene oxide or propylene    60
    oxide. The marked superiority stems from the fact that
    1,2-butylene oxide is about 3 times safer than propylene
    oxide when long exposure to it is required and about
    3.5 times safer than ethylene oxide. Insofar as ease
    of detonation is concerned, 1,2-butylene oxide has about      65
    the same explosive limits as propylene oxide. However,
    1,2-butylene oxide is significantly easier to handle
    because its boiling point is nearly twice that of
    propylene oxide--63° C. as opposed to 34.2° C.--and over
    6 times that of ethylene oxide. According to this invention
    1,2-butylene oxide may be used in either its natural           5
    liquid state or gelled with a hereinafter named gelling
    agent.


    DESCRIPTION OF THE PREFERRED
    EMBODIMENTS                                                   10

    In one embodiment of this invention, neat 1,2-butylene
    oxide liquid is used as the fuel in a fuel air explosive
    weapon in lieu of the previously most commonly used
    fuels, ethylene oxide and propylene oxide. It has been
    found that butylene oxide is significantly less toxic than    15
    either of the two commonly used oxides. Air containing
    400 parts per million of 1,2-butylene oxide may be
    breathed safely for up to 8 hours with no undesirable
    results as compared to 100 parts per million for propylene
    oxide and only 50 parts per million for ethylene              20
    oxide.

    1,2-butylene oxide offers a second distinct advantage
    over ethylene oxide and propylene oxide. Its boiling
    point is 63° C. as opposed to 10.4° C. and 34.2° C.           25
    respectively for the other two oxides. Thus, loading
    operations are much easier to carry out. No special
    equipment is needed for its handling.

    Tests have shown that, insofar as ease of detonation is
    concerned, 1,2-butylene oxide is similar to propylene         30
    oxide. Its explosive limits range from about 3.1 to 25.1
    percent by volume as opposed to 3.1 to 27.5 percent by
    volume for propylene oxide. Thus, its significantly
    lower toxicity can be taken advantage of with very little
    loss in explosive efficiency.                                 35

    Another factor contributing to the ease of handling of
    1,2-butylene oxide is its vapor pressure. The vapor
    pressure of 1,2-butylene oxide is only 207.0 mm Hg at
    25° C. as opposed to 1,292.0 for ethylene oxide and
    569.0 for propylene oxide.                                    40

    In a second embodiment of this invention, 1,2-butylene
    oxide may be used in a gelled state. It has been
    found that, if 1,2-butylene oxide is gelled by adding
    about 3 to about 10 weight percent of a gelling agent
    such as SiO_2 (Cab-O-Sil), particulate carbon or aluminum     45
    octoate, it will still be dispersed into a detonable
    cloud by a typical fuel air explosive weapon. This is
    perhaps the best mode of practicing this invention for
    several reasons. First, the gel is more easily handled
    than the neat liquid. Second, if spilled the gel will not     50
    disperse as a liquid will.

    In storage, no self-polymerization of 1,2-butylene
    oxide has been detected. Thus, a warhead loaded with
    the material has an indefinite shelf-life.

    I claim:                                                      55

    1. In a method for producing an explosion comprising the
    steps of dispersing a cloud of liquid particles in the
    air and detonating the cloud, the improvement residing
    in utilizing 1,2-butylene oxide in gel form as said liquid.

    2. A method according to claim 1 wherein said gel consist
    essentially of 1,2-butylene oxide and a gelling agent
    selected from the group consisting of SiO_2, particulate
    carbon and aluminum octoate.                                  60

    3. A method according to claim 2 wherein said gelling
    agent is present in an amount in the range of from            65
    about 3 to about 10 weight percent.

           *       *       *       *       *