Abstract: A pressure-reducing device in a pneumatic transport system for particulate material having a first and a second transport channel which are arranged so that, at the transition between the two channels, the gas/particulate flow is bent through 180.degree.. After the bend, a throttling means is arranged. The throttling means consists of an annular nozzle, the inlet side thereof being rounded with an arcuate profile in radial section. The pressure-reducing device may be included in a transportation system for feeding particulate material out from a pressurized container to a container under a lower pressure, for example for removing dust from a dust separator in a PFBC plant to a collecting container.

Abstract: A power plant with a combustion chamber (8) with a fluidized bed (14) and a device for adjusting the bed height, comprising a storage container (21) for bed material, the storage container (21) being connected to the combustion chamber (8) by a first conduit (22) for feeding out bed compound from the combustion chamber (8) to the container (21) and a second conduit (23) for returning bed compound from the container (21) to the combustion chamber (8). The storage container (21) is connected, via a conduit (34) with a valve, to a space having lower pressure than the pressure in the combustion chamber (8). The return conduit (23) is connected, via a conduit (67) with a valve, to a pressure gas source (10) having higher pressure than the pressure in the combustion chamber (8). Transport of bed compound from the combustion chamber (8) is achieved by reducing the pressure in the storage container (21).