Abstract: In a rotary drum type device for coating granular solids of the type having a rotary drum with a perforated cylindrical wall section, a supporting ring surrounding the cylindrical wall section of the drum for rotatably supporting the same, and inlet and outlet duct means defined within the supporting ring and opening to the perforated cylindrical wall section of the drum in such a way that the hot air or the like is directed from the top of the drum toward a tumbling bed of granular solids formed within the drum, the perforated cylindrical wall section is so divided that the area which faces the opening of the inlet duct means will not face the opening of the outlet duct means and vice versa, whereby the coating agent which is deposited on the walls of the small holes of the cylindrical wall section facing the opening or inlet of the outlet duct means can be prevented from being separated and falling into the drum by the hot air or the like flowing through the opening of the inlet duct means into the drum.

Abstract: A rotary drum type apparatus for applying a coating to tablets including a rotary drum supported by a support frame for receiving a body of tablets to be coated by spraying with a solvent. The drum is inclined through about 10-20 degrees in such a manner that its front surface is turned upwardly, and an air inlet tube and an air outlet tube are connected to the support frame in positions slightly displaced toward the rear surface of the support frame from the center line of the support frame extending perpendicular to the center axis of the drum. The support frame cooperates with an outer periphery of the drum to define an air suction duct disposed on the front side of the support frame and an air exhaust duct disposed on the rear side of the support frame so that a smooth flow of hot blast through the drum can be obtained.

Abstract: In a device for coating granular solids of the type having a double-cone rotary drum which is perforated so as to permit the flow of air or gas into and out of the rotary drum and which is tiltable about the axis at right angles of the axis of rotation of the rotary drum so that in the case of the discharge of product solids, the discharge opening of the rotary drum may be directed downwards, axially annular insulating covers are provided which ensure the effective thermal insulation of the rotary drum when the hot air or gas is blown thereinto. The present invention further provides means which are very effective in gas-tightly sealing the gas supply and exhaust passages defined in the duct around the rotary drum and the annular covers attached thereon so as to provide the air thermal insulation layers.

Abstract: A device for coating granular solids has a rotary drum and a casing or housing air-tightly housing the rotary drum. The space between the rotary drum and the casing is divided by sealing means into a gas supply passage and a gas exhaust passage which in turn are communicated with a gas supply duct and a gas exhaust duct, respectively. The rotary drum is of a double-cone structure consisting of a cylindrical section and frustoconical side walls, and the cylindrical section consists of a plurality of circumferentially arcuated louvers overlapped one upon another and radially spaced apart from each other at a suitable distance to define gas passages between the interior and exterior of the rotary drum.