Abstract: A fish pond plant comprises a fish pond (1), a first conduit (2) for conducting sea water from the sea (11) to the fish pond (1), a second conduit (3) for conducting water from the pond to the sea, and pump means (4) for circulating sea water through the pond (1) via said conduits (2,3), a water magazine (5) associated with a solar collector (6) adapted to heat the magazine water, and a first heat exchanger (8) connected to said first and second conduits (2,3) to transfer heat from the sea water leaving the pond (1) to the fresh sea water entering the first conduit (2).A second heat exchanger (7) may be connected to the first conduit (2) and adapted to heat sea water fed to the first conduit (2) by heat exchange with warm magazine water.

Abstract: There is provided a solar collector apparatus comprising a rotatable platen supporting a solar collector, means for rotating the platen such that the solar collector follows the wandering of the sun, said solar collector comprising a plurality of elongated parallel sun radiation concentrators, each concentrator being associated with an elongated conduit which is arranged to be subjected to the radiation concentrated by the concentrator, and pump and control means for circulating a liquid through the conduits via a liquid magazine, the concentrators being located on the platen with their longitudinal axes aligned in the vertical plane of the solar direction, said means for rotating the platen being adapted to maintain such alignment of the concentrators.

Abstract: There is provided a heat exchanger apparatus comprising a plurality of mutually identical heat exchanger coils. Each coil has the shape of a cup. The coils are placed in close relationship on both sides of a base plate which blocks a flow channel. The base plate exhibits a plurality of orifices, and a coil is placed over each orifice with its rim in contact with the base plate and surrounding the edge of the orifice, but only one coil is assigned to each orifice. Adjacent coils on opposite sides of the base plate are stagger so that their rims overlap each other without covering any part of the orifice assigned to the adjacent coil on the opposite side of the base plate.

Abstract: There is provided a heat exchanger system for transfer of heat in the warm exhaust air from a mine to the cold input air flow to the mine. In the system there is provided a heat supply means, which supplies heat, recovered from the exhaust air, to the input air heat exchanger when an exhaust air heat exchanger is disconnected for defrosting.

Abstract: There is provided a distillation plant of the multiple stage flash distillation type. The plant comprises a reinforced concrete shell which is divided into a large number of flash chambers and a heat supply chamber by means of partitions. A bundle of condensation tubes, preferably of plastic, extend throughout all of the chambers. The inlet and outlet manifolds for the tube bundle are defined by an end of the shell and an adjacent partition. The shell has preferably a plastic coating or consists of a polymer concrete. Preferably, the partitions consist of or comprise plastic so that a bundle of plastic tubes may be sealed to openings in the partitions by gluing or welding.

Abstract: A heat exchanger coil is formed by winding a plurality of flexible tubes to form a coil. The turns of the coil are separated in the axial direction of the coil by means of radially disposed separator elements. The turns of the coil are separated in the radial sense by inserting separating means. Said separating means are positively controlled by the radially disposed separating elements relatively to the coil, both in the direction of winding the coil and in the opposite direction. The separating means are locked in the radial direction of the coil by winding the tube over them.

Abstract: There is provided a convector for heating rooms and a method for manufacturing same. This convector comprises a plastic tube wound to form a flat coil. The plastic used for the tube is preferably a cross-linked plastic, such as cross-linked polyethylene. Some of the coil-turns may be displaced inwards or outwards from the basic shape of the tube coil, in order to improve the convection.