Abstract: In an axial jet mill, an internal structure having a cylindrical outer surface is positioned within a housing to establish a raceway for the circulating movement of gas and solid material while maintaining the gas and solid material in close proximity to the outlets of gas nozzles distributed around the perimeter of the raceway. Solid material enters the jet mill though a bottom wall of the housing and passes into the raceway though gaps between the bottom of the internal structure and a bottom wall of the housing. Particles and gas exit the jet mill though a central outlet in the housing located above the internal structure.

Abstract: In an axial jet mill, an internal structure having a cylindrical outer surface is positioned within a housing to establish a raceway for the circulating movement of gas and solid material while maintaining the gas and solid material in close proximity to the outlets of gas nozzles distributed around the perimeter of the raceway. Solid material enters the jet mill though a bottom wall of the housing and passes into the raceway though gaps between the bottom of the internal structure and a bottom wall of the housing. Particles and gas exit the jet mill though a central outlet in the housing located above the internal structure.

Abstract: Preground cocoa cake powder is mixed with pH neutral or alkalized water and continuously fed into a recirculating jet mill operated by superheated steam. In the mill, butterfat is separated while the cocoa cake is ground to a uniform fine particle size. Flash vaporization of the water mixed with the cake causes the particles to “explode,” improves separation of butterfat, and aids in the grinding action of the mill. Solid particles in the exit stream of the mill are recovered by cyclone separation, as a finely ground, defatted, cocoa product. Exhaust gases and butterfat exiting the cyclone separator system are fed into a desuperheater, where butterfat is recovered. The exhaust of the desuperheater is delivered to a bag collector for further separation and recovery. Other components that have a negative effect on the cocoa powder are neutralized and/or removed, providing an enhanced taste to the final product.

Abstract: In a vertical loop jet mill, a grinding chamber in the lower part of the loop is trapezoidal in shape with side walls converging toward the outside of the loop. Removable nozzle plates are provided in the lower parts of the side walls of the grinding chamber, and the nozzles are directed so that gas streams from nozzles on one side intersect gas streams from nozzles on the other side. A removable insert, with trapezoidal end panels forms the upper wall of the grinding chamber.

Abstract: In a vertical loop jet mill, a grinding chamber in the lower part of the loop is trapezoidal in shape with side walls converging toward the outside of the loop. Removable nozzle plates are provided in the lower parts of the side walls of the grinding chamber, and the nozzles are directed so that gas streams from nozzles on one side intersect gas streams from nozzles on the other side. A removable insert, with trapezoidal end panels forms the upper wall of the grinding chamber.

Abstract: A process for vitrifying waste material containing environmentally hazardous metals or metal compounds includes drying a waste material using a flash dryer, where the drying is carried out at a temperature low enough to prevent volatilization of hazardous metals and metal compounds contained in the waste material. Preferably, more than about 95% of the water is removed form the waste material. The dried waste material is transferred from the flash dryer into a melting vessel, melted, collected and cooled to form a vitrified mass of waste material. Gases produced during the process of the invention are filtered, treated, and released into the atmosphere.

Abstract: A process for vitrifying waste material containing environmentally hazardous metals or metal compounds includes drying a waste material using a flash dryer, where the drying is carried out at a temperature low enough to prevent volatilization of hazardous metals and metal compounds contained in the waste material. Preferably, more than about 95% of the water is removed form the waste material. The dried waste material is transferred from the flash dryer into a melting vessel, melted, collected and cooled to form a vitrified mass of waste material. Gases produced during the process of the invention are filtered, treated, and released into the atmosphere.

Abstract: The expenditure of energy required to feed solid material into a jet mill or flash dryer is significantly reduced by the use of a novel feed system in which a blower, operating at a pressure slightly higher than the pressure within the jet mill or flash dryer, produces a stream of air which transports the solid material to be treated. Solid material is introduced into the stream of air through a rotary valve in which the rotary element is disposed for rotation about an axis parallel to the direction of air flow and its blades move through the path of air flow to prevent the accumulation of material on the blades.

Abstract: Significant improvement in the sharpness with which particles are classified by size in a recirculating jet mill is achieved by the provision of an elongated, flexible barrier strip located adjacent the outermost part of the wall of the classifier section. The positions of both ends of the strip are adjustable for controlling classification. The cross-section of the classifier section is pear-shaped, the narrow portion of the cross-section being toward the outside of the classifier section, and the barrier strip being within said narrow portion. An auxiliary outlet for large particles can be provided behind the barrier strip.