Abstract: A method of preparing an adsorbent which contains a medium, which medium may comprise water. The medium is removed from the adsorbent by a hot regeneration gas, and the adsorbent is then cooled, wherein heat recovered during said cooling is used to heat the regeneration gas in a heat accumulator/exchanger. In order to improve the dewpoint characteristics of the dried gas, the adsorbent is passed successively through the following zones:an adsorption zone in which the adsorbent adsorbs the given medium;a regeneration zone in which the regeneration gas is passed through the adsorbent; anda cooling zone in which heat is withdrawn from the adsorbent, to be transferred to the heat accumulator/exchanger. An apparatus suitable for carrying out the described method is also described.

Abstract: A method of and an apparatus for drying plastic granulates in which the drying process is intermittently interrupted and dried plastic granulates are conveyed by a conveying medium during preset time periods which are short with respect to the periods of drying the plastic granulates within a drying container.

Abstract: A device for producing a continuous stream of dried gas supplied to a dryer for drying-up a particulate plastics material comprises a number of blowers and a number of adsorbent means-containing containers connected to heating arrangements which are inserted in the conduits leading to the drier. Each blower is immediately connected to an assigned adsorbent means-container and is switchable to operate for conveying dried-up gas and for regenerating adsorbent means in the container.

Abstract: A method and an apparatus for drying bulk material, preferably of plastic granules, in a drying hopper by means of dry air, whereby the exhaust air escaping from the drying hopper is dried in a drier containing a humidity adsorption means and fed to the bulk material as dry air. In order to utilize more efficiently the adsorption capacity of the adsorption means and to save thus thermal energy, the invention provides that the exhaust air is cooled by the heat-adsorbing portion of a heat pump before it is fed to the adsorption means. Preferably, a heat-conveying portion of said heat pump is used for preheating the dried air before being fed to the drying hopper for drying the bulk material.

Abstract: In order to ensure, in a method for extracting gases and vapors from plastics granules and powders which are being pre-heated and dried in a drying hopper by a stream of dry air flowing into the lower region of the hopper while the outlet air is extracted from the hopper above the granules, that also that part of the plastics granules which is in the lowermost region of the drying hopper is reliably dried and warmed, the method provides that a portion of the stream of dry air is guided in a direction opposite to that of the main stream and is extracted at the lowermost point of the hopper. A drying hopper for plastics granules is suitable for carrying out the method according to the invention which has in its upper part a feeding opening for the granules and an air outlet pipe, and further has a lower outlet port for the granules and an air inlet pipe which ends inside the hopper in an air distributing opening, wherein a second air outlet pipe is mounted in the hopper near the outlet port.

Abstract: The exhaust air from a bulk material drying hopper is conveyed through a chamber filled with an adsorbing medium and the air is fed back to the drying hopper in a closed circuit. The chamber is regenerated at intervals by a counterflow of drying gas. The frequency of regenerating the chamber is controlled as a function of the temperature of the exhaust air.

Abstract: A body of pulverulent material is confined in a receptacle, and a screw conveyor having a vertical axis conveys a predetermined quantity of the material per unit of time in the upward direction. The amount of the pulverulent material which is being conveyed is such that it fills the space between the turns of the helical conveyor screw of the screw conveyor, which is surrounded by a jacket, only in part, thus leaving a passage in the screw conveyor through which a stream of drying air is conveyed in contact with the pulverulent material so that the drying air withdraws moisture from the material. The rotational speed and/or the pitch or spacing of the consecutive turns of the conveyor screw is so selected that only such an amount of the pulverulent material enters through an opening in the jacket of the screw conveyor while the space between two consecutive turns is juxtaposed with the opening as to only partially fill such a space.

Abstract: The exhaust air from a bulk material drying hopper is conveyed through a chamber filled with an absorbing medium and the air is fed back to the drying hopper in a closed circuit. The chamber is regenerated at intervals in a second circuit. The air throughput through the hopper is controlled as a function of the temperature of the exhaust air.

Abstract: An apparatus for the adsorption of molecules from a gaseous medium comprises at least two adsorption chambers for receiving an adsorbent; at least one pair of ducts forming inlets and outlets associated with each of said adsorption chambers; means for passing the gaseous medium selectively into and out of said ducts and adsorption chambers so as to form an adsorption circuit; means for passing a hot gaseous regeneration medium into and out of said ducts and adsorption chambers so as to form a regeneration circuit; valve means associated with said ducts for selectively including one or the other pair of ducts and adsorption chambers in said adsorption circuit or in said regeneration circuit, the said valve means comprising a pair of cooperating and aligned, relatively rotatable valve discs, and openings provided in said valve discs for connection with said ducts forming the adsorption and regeneration circuit, all of said openings being equidistant from the central axis of said discs and the said openings bein

Abstract: An adsorption chamber is included into a conduit which further includes a blower and at least one heating arrangement; check valves are provided in the conduit which operate in dependence on the pressure conditions prevailing in the respective conduit sections. The blower may be operated in two mutually opposite directions, in one direction propelling the medium to be adsorption treated through the adsorption chamber, in the reversed direction propelling a regeneration medium through the adsorption chamber in counterflow. The adsorption chamber may be filled with two different adsorbents capable of adsorbing moisture in different temperature ranges. Thermostats may be provided for controlling the energization of the heating arrangement.