Abstract: A fan impeller has a hub and fan blade units with fan blades connected to the hub. The fan blade units are made of plastic material reinforced with first fibers for transmitting forces acting on the fan blades into the hub. The first fibers extend substantially parallel to a longitudinal direction of the fan blades. The first fibers are bundled at a radially inner end of the fan blades to form a tubular structure. The tubular structure has a free end that is bent radially outwardly substantially about 180.degree. to form an end ring. The end ring has a convex surface facing the hub and a concave surface facing the fan blade. Each fan blade unit has a fastening element with an annular groove for receiving the end ring, the fastening element connected to the hub. Each fan blade unit further has a fastening ring inserted into the concave surface. The fastening ring clamps the end ring at the fastening element.

Abstract: An apparatus for damping the noise of water charged in a cooling tower onto the top of heat exchanger elements by a distributing device and dropping down from the bottom of the heat exchange elements into a collecting basin, by means of vertically inclined impact surfaces of rigid insert elements which are arranged above the collecting basin in the cooling tower. In order to avoid the direct impingement of drops of water onto the surface of the water without impairing access to the collecting basin even with a greatly varying level of water, the lower edge of the rigid impact surfaces is arranged above the maximum water level in the collecting basin and extended by a flexible guide tail which extends into the water of the collecting basin with a minimum water level. This guide tail can be pushed aside and held out of the way upon cleaning and continuously diverts the water film into the vertical direction so that a noisy separation of the water film is made impossible.

Abstract: A sprinkler head for water spray cooling installations, attachable to a bottom wall of a hot water distribution conduit or distribution channel, the sprinkler head having a spray pipe reaching through an aperture of said bottom wall and a carrier shell or an open carrier cage surrounding the spray pipe and supporting one or several superposed cone-shaped spray plates at a short distance from the mouth of the spray pipe. Each spray plate has a pattern of spray distributor slots extending through its wall, so that a portion of the water passes through these slots and covers the central area underneath the sprinkler head, for an optimal distribution of the water.

Abstract: A flow grate structure for cooling installations in cooling towers in which several identical square grate units are vertically aligned in a stack, but so oriented, that their offset cell fields and splash plates are staggered in a regular pattern, in which the splash plates cover, in their vertical projection, a major portion of the flow cross section of the grate unit stack.