Abstract: Animal feeds and methods of forming animal feeds are provided wherein the feeds are formed by mixing poultry house litter and slaughterhouse wastewater sludges, followed by drying of the resulting mixture in a hot air convection rotary drum dryer. The resulting feed is high in fat and protein, and can be fed as a meal or in pelletized form. In a preferred embodiment, the feeds are formed by mixing litter comprising poultry manure and poultry feed with wastewater sludges comprising poultry fat, followed by drying in the rotary drum dryer. The feeds of the invention can be used to provide a high fat, high protein diet to any animal, particularly ruminants and aquatic animals.

Abstract: An anti-clogging rotary drum dryer for drying stranded material is provided which includes a tubular, rotatable housing having an inlet for receiving drying gas and wet material, as well as first and second, apertured, telescopically interfitted tubes within the housing and defining the dryer flow path. The first and second tube apertures are designed for passage of the stranded material without clogging, and filler and lifting flight structure is provided within the dryer for assuring smooth, trouble-free operation.

Abstract: An improved multiple-pass drum dryer (12) is provided which includes an enlarged, flighted premixing zone (65) including a frustoconical, converging transition section (68) leading to an innermost passageway (138) of a concentric multiple-pass final drying section (24). Product and drying air fed to the premixing zone (65) undergo an acceleration in the transition section (68), whereupon product and air are decelerated during travel through the multiple-pass final drying section (24). In this way, product is moved along a first region (66) of the premixing zone (65) at a relatively low average speed so that the initially wet product is proximally exposed to heated gases emitted from a burner for a maximally effective time period. The product then experiences a relatively rapid acceleration in the transition section (68) due to negative pressure from a downstream fan and decreasing cross-sectional area in the transition section (68).

Abstract: An improved, high efficiency rotary drum dryer and method is disclosed which achieves outstanding thermal efficiencies by provision of a multiple-pass rotary dryer designed so that the product to be dried is first conveyed through an outermost drum of relatively large cross-sectional area and then through succeeding internal drums of progressively smaller cross-sectional areas. In this way, the velocity of induced air currents traveling through the dryer increases from pass to pass, with the result that the net velocity of product through successive passes also increases. The preferred dryer also includes housing structure in surrounding relationship to the innermost drum permitting introduction of relatively low humidity ambient-derived air into the central drum so as to lower the partial pressure of moisture in the drying atmosphere, thus promoting the final stage of drying.

Abstract: An improved, high efficiency rotary drum dryer and method is disclosed which achieves outstanding thermal efficiencies by provision of a multiple-pass rotary dryer designed so that the product to be dried is first conveyed through an outermost drum of relatively large cross-sectional area and then through succeeding internal drums of progressively smaller cross-sectional areas. In this way, the velocity of induced air currents traveling through the dryer increases from pass to pass, with the result that the net velocity of product through successive passes also increases. The preferred dryer also includes housing structure in surrounding relationship to the innermost drum permitting introduction of relatively low humidity ambient-derived air into the central drum so as th lower the partial pressure of moisture in the drying atmosphere, thus promoting the final stage of drying.

Abstract: An improved, high efficiency rotary drum dryer and method is disclosed which achieves outstanding thermal efficiencies by provision of a multiple-pass rotary dryer designed so that the product to be dried is first conveyed through an outermost drum of relatively large cross-sectional area and then through succeeding internal drums of progressively smaller cross-sectional areas. In this way, the velocity of induced air currents traveling through the dryer increases from pass to pass, with the result that the net velocity of product through successive passes also increases. The preferred dryer also includes housing structure in surrounding relationship to the innermost drum permitting introduction of relatively low humidity ambient-derived air into the central drum so as to lower the partial pressure of moisture in the drying atmosphere, thus promoting the final stage of drying.