Abstract: Metering or dosing device for sand spreading apparatuses with a metering piston for sealing off and releasing the throughflow opening for the material to be spread, in which the metering piston and the opposite housing wall of the passage hole have profiles overlapping each other so that a labyrinth-like outflow of the spread material results.

Abstract: A sprinkling appliance (1) comprising a reservoir (2), a metering means (3) and a preferably compressed-air actuated conveying and dispensing (5), respectively, for dispensing the sprinkling material, wherein the metering means (3) for metering sprinkling material has at least one conveyer or closure surface (19), respectively, capable of being rotated about an axis of rotation (4′).

Abstract: The invention relates to a filter installation having at least one filter element for the filtering of a crude gas containing impurities, in particular particulate impurities. The crude gas flow to be filtered can be supplied to the filter installation via a crude gas line and at least two filter modules, each having at least one filter element, are provided. Each filter module is fluidly connected to the crude gas line via a module crude gas line through which a part of the crude gas flow can be supplied to the respective filter module. Each module crude gas line has a blocking member through which the supply of the respective partial crude gas flow can be interrupted for the cleaning of the filter element of the respective filter module.

Abstract: A method of cleaning dryer exhaust gases during the drying of wood chips, wood fibers and the like is described in which at least one part of the dryer exhaust gases is filtered at a temperature lying above its dew point. At least one part of the particles which are filtered out in this way is conveyed, together with flushing air which likewise has a temperature above the dew point, substantially continuously into a combustion chamber and is burned there for hot gas generation.