Abstract: The removal of impurities from exhaust gases takes place by cooling the exhaust gas by means of a circulation gas and condensing out of the impurities in two groups of reversible heat exchangers. Each group consists of two precoolers and one low temperature cooler. While the impurities condense out in one group, they are thawed in the other group. In order to simplify the control, only one precooler is used in each group, which is charged with two inside gases, namely, the exhaust gas and the circulation gas. Only two simple control systems which can be easily program-controlled are then required for the purification process. In addition, the temperature increase of the circulation gas in the circulation gas blower can be utilized for heating up purposes in the group to be thawed.

Abstract: A device for cooling bulk material by low-boiling liquefied gas includes a precooling zone and a spraying zone. The precooling zone is inclined from the horizontal downwardly toward its discharge end to which is attached a rotatable drum-shaped chamber as its spraying and draining zone which is constructed as a worm conveyor. Where used for scrap tires, a spray pipe is provided at the discharge end with a ring mounted on the internal wall between the spray orifices and the discharge opening, the ring having a thickness corresponding to the average tire thickness.

Abstract: A transportation device for conveying large volume and heavy goods to be cooled in cooling tunnels is characterized by a stationary grate mounted to the tunnel floor with supports for this grate located at intervals with respect to each other parallel to the direction of conveyance, and a movable grate having its supports disposed between the supports of the stationary grate with the movable grate driven in a closed curve or loop in a vertical plane parallel to the direction of conveyance in such a manner that the supporting surfaces of the movable grate are substantially above the supports of the stationary grate when moved in the conveying direction but are substantially below the supports of the stationary grate when moved against the direction of conveyance.