Abstract: A device for conducting a fluid in heat transfer relationship with another liquid comprises a conduit through which the fluid flows to be heated or cooled by the other fluid flowing around the conduit. An elongated, thread like element helically extends around the conduit with the windings spaced from each other, causing the fluid flowing around the conduit to undergo circulation for improved heat transfer relationship.

Abstract: Water may be purified by passage through a filter of thickness 2 cm to 1 m composed from fibers obtained from a melt of composition about 80% diabase mineral and about 20% lime, at least 90% of the fibers having a diameter below 15 microns, the fiber solids content of the material being at most 20% of the volume at a flow rate above 10 meters per hour to remove suspended particles.

Abstract: The invention relates to a heating system comprising a compressor for supplying a heated medium, preferably a heated gas, for example Freon gas, to two pipe coils each adapted to heat one fluid by means of the medium, the fluid flowing through the pipe coils and from the pipe coils to the compressor. One fluid is stored within a tank through which one of the pipe coils extends. The other fluid is supplied by a regulator to a heat exchanger wrapped around the tank and second pipe coil. The compressor and regulator as well as flow of medium to the two pipe coils are controlled as a function of the temperatures of the two fluids.