Abstract: A fan includes a frame, rotor supported by this frame and having a central hub and a number of blades and a drive mechanism for rotatably driving the rotor, in addition to a ring to which the end zones of the blades are connected. The ring is assembled from two part-rings of the same form which each include a circular strip of sheet material, the free ends of which are mutually connected to form the outer surface of a truncated cone, and a third part-ring which mutually connects the inner edges of the first two part-rings. The end zones of the blades are connected to the third part-ring. The ring has a diameter of more than about 1.50 m. The number of blades amounts to at least eight. The blades are hollow and include a framework structure which is provided with a skin connected thereto.

Abstract: A fan includes a frame, rotor supported by this frame and having a central hub and a number of blades and a drive mechanism for rotatably driving the rotor, in addition to a ring to which the end zones of the blades are connected. The ring is assembled from two part-rings of the same form which each include a circular strip of sheet material, the free ends of which are mutually connected to form the outer surface of a truncated cone, and a third part-ring which mutually connects the inner edges of the first two part-rings. The end zones of the blades are connected to the third part-ring. The ring has a diameter of more than about 1.50 m. The number of blades amounts to at least eight. The blades are hollow and include a framework structure which is provided with a skin connected thereto.

Abstract: A heat exchanger, comprising a shell designed as a pressure vessel, provided with shell-sided supply and discharge means with which the shell can be flowed through with a first medium under pressure. The heat exchanger further comprises a nest of tubes extending at least partly within the shell, provided with tube-sided supply and discharge means with which the tubes from the nest can be flowed through with a second medium in heat exchanging contact with the first medium under pressure. The individual tubes of the nest are each included with a supply and a discharge side in tube bores extending substantially transversely to the plane of a tube plate included in the shell. The heat exchanger has the special feature that the tubes are connected with the tube-sided supply and discharge means via connecting channels located in the plane of the tube plate and crossing the tube holes.

Abstract: An apparatus for carrying out a physical and/or a chemical process, such as a heat exchanger, a reservoir, in which a fluidized bed of granular material is present, is provided with upwardly directed tubes to a top box. Particles circulate up through the tubes, to a downcomer arranged outside the reservoir. The top of the downcomer is connected to a separating device, and the bottom of the downcomer opens into a collecting reservoir. The collecting reservoir communicates via a valve with the fluidized bed in the reservoir.

Abstract: An apparatus for carrying out a physical and/or chemical process, such as a heat exchanger, comprising a reservoir (1) provided with upwardly-directed tubes (2), in which reservoir (1) a fluidized bed is present consisting of granular material and maintained by medium to be treated. The invention is provided with means for causing fluidized bed particles to circulate from a bottom box (3) of the reservoir (1) through the riser pipes (2), a top box (4) and a downcomer (15) back again to the bottom box (4), and with a closable bypass line (27) for feeding a portion of the fed medium to the riser pipes (2) while shortcutting the fluidized bed.

Abstract: A dipole separator, wherein solid or liquid non-conductive particles are removed from a gas stream by an electric D.C. field generated between two co-axial cylindrical electrodes and having a relatively low intensity so that substantially no ionization occurs in the gas stream. In order to increase the separating efficiency, one of the electrodes, preferably the inner electrode, is provided through at least a part of its axial length with a covering consisting of a semi-conductive fibrous material having a multitude of outwardly projecting fibers, such as asbestos.