Abstract: A method and a throttling device to control an air flow in a channel (1) or in a channel system. The air flow is brought to pass at least a first channel portion having a successively tapering channel cross section area being formed by a adjustable throttling device (4) in the channel, the air thereafter is led to an other channel portion having a cross section with an increased throttling formed by the adjustable throttling device, to continue flowing in the channel portion with the increased throttling over a distance being considerably longer than the distance between the outer wall of the throttling device and the inner wall of the of the channel portion to thereafter leave the second channel portion with the increased throttling at a third channel portion and be transferred into the not throttled channel.

Abstract: A method of preparing an installation of channel using units in several rooms on the one and same floor so as to allow a subsequent completion of units with multiple channel elements. Onto a flooring support between a distributing central unit and the rooms on the floor, the flexible channel elements which are enclosed in an exterior casing, are enclosed. These channel elements are a) a separate channel or conduit for the flow of a hot or cold brine to and from radiators in the rooms, b) channels for supplying electricity and/or for communicating with the units; and c) a channel space for fresh air between the elements. The floor is then finished to cover the multiple channel elements.

Abstract: A method of continuous mixing and homogenization of a main substance and at least one additive substance, liquids in particular, and a device for executing the method, said device comprising a primary conduit (1) for circulating the main substance, a secondary conduit (5) for circulating the main substance and the additive substance, to which conduit a mixing unit (7) is connected, and at least one proportioner (4) for supplying the additive substance, said proportioner constituting a connection between the primary and secondary conduits, the main substance and the additive substance being supplied to the secondary conduit in dependence of a discharge from the secondary conduit.