Abstract: A butt reducer machine is provided to remove excess wood from the swelled butt ends of logs. Cutting heads supported on pivoting arms, carried in turn within a rotating frame, are caused to oscillate circumferentially about the portion of the log to be removed. This butt-removal process may be carried out while a log is in motion longitudinally, either before or after the log enters a de-barking machine. The process may also be effected on a stationary log.

Abstract: A tank contains water heated by a heat pump having a heat exchanger part in a waste-water reservoir or in a waste air conduit and a further heat exchanger part in the water of the tank, heat being picked up in the reservoir or conduit and delivered to the water in the tank. The latter is a closed tank and the space above the water is connected to the inlet of a motor-driven centrifugal turbine. The lower pressure thus formed above the level of the water by the turbine inlet causes evaporation of the water and the turbine compresses this vapor into pressurized steam.