Abstract: A float assembly for supporting a vehicle having three cylindrical float tubes tangentially secured together by a suitable adhesive with two of the float tubes being positioned so that the centerlines thereof are in a horizontal plane. The three float tubes are secured together to form a pyramid whereby the intersections thereof form a Y-shaped cross-sectional configuration so that the centers of the cylindrical float tubes form a triangle which is or approaches an equilateral triangle. Girths are secured to the float assembly in the horizontal plane and are suitably bolted to skids which are attached to the vehicle. The forward and aft ends of each of the cylindrical float tubes are frustoconical shaped cones which are inclined upwardly to increase the maneuverability of the vehicle and prevent pitch poling. The outboard and top float tubes have bulkheads to provide several sections to enable the float tubes to provide flotation in the event that one of the sections is deflated.

Abstract: Uniform heat treatment of particulate material of nonuniform gradation in a vertical heat treating vessel such as a vertical kiln or retort is affected by regulating the heat input to a heat treating zone in the vessel in response to changes in specific gravity of the mass of particles passing into the heat treating zone as detected by measurements such as differential pressure changes of combustion supporting fluid and process gas flowing into and from the heat treating zone to result in a balance between particulate mass flow and heat input and substantially uniformly heat treated particulate material.