Abstract: An apparatus for fracturing a well has a propellant charge held by a carrier, and upper and lower restrictor plugs secured to the carrier above and below the propellant charge, respectively. The restrictor plugs allow a restricted flow of combustion gases generated by the propellant charge to pass the restrictor plugs, but maintain sufficient pressure in the well between the restrictor plugs to fracture the formation surrounding the well.

Abstract: An apparatus for fracturing wells employs a propellant charge with a metallic foil to rapidly ignite the surface of the propellant charge. The assembly can be covered with an protective coating to protect against fluids in the well bore.

Abstract: An apparatus for fracturing wells employs a propellant charge and an ignition cord wrapped around the outer surface of the propellant charge to rapidly ignite the outer surface of the propellant charge.

Abstract: A cement producing system includes a rotary kiln, a riser duct having lower portion communicably connected to the rotary kiln to pass process materials thereto, and a down draft calciner having a lower portion communicably connected to the lower portion of the riser duct. A tertiary duct is communicably connected to an upper portion of the down draft calciner to receive heated tertiary gas therefrom and a suspension burner is operably disposed in the down draft calciner in a manner to permit receipt of combustible waste and suspension of the waste therein for combustion thereof. A method of producing cement using the burner in the down draft calciner is also provided.