Abstract: A filter apparatus and filtering system which is particularly applicable for extracting particulated material from hot gases comprising a collector overlying a portion of the upstream face of the filter element for applying a reduced pressure to the particulate filter cake formed thereover to effect a dislodgement and recovery of the filtered particulate material. The collector is movable to progressively traverse substantially the entire upstream face of the filter element to effect a cleaning thereof by removal of the filter cake without interruption of the operation of the filtering system. The invention further encompasses a separator for cleaning the granular filter medium withdrawn from the filter apparatus and for recycling the cleaned filter medium back to the filter apparatus.

Abstract: The staging or compounding of drag-type turbines having a high energy input is herein accomplished by disposing successive stages of a drag turbine in radially offset relation, i.e., nested relationship with nozzles between radially displaced stages mounted either in fixed spatial position or mounted for rotation with the upstream rotor and providing either like or opposite directions of rotation of successive stages. The successive radial stages of the present invention are separately coupled to coaxial drive shafts which, in turn, may be appropriately coupled to rotary output means in a conventional manner to provide the output power and high efficiency of the multistaged turbine.