Abstract: Vacuum filter belt apparatus has a continuous belt with an upper run at which suction filtering occurs, via passages which pass through a central thicker portion of the belt and open into a vacuum chamber. To avoid high frictional contact between the belt and the upper side of the vacuum chamber, the thick central portion of the belt passes right through the vacuum chamber from above to below and is supported below the chamber e.g. by rollers or a pressurized chamber.

Abstract: Vacuum filterbelt apparatus has a continuous belt moved by driving means along a continuous path which includes an operative portion at which filtering of material lying on the belt occurs. Apertures in the belt communicate with a slot in the top of a vacuum chamber beneath the belt, to apply suction to the material. At the operative portion, the belt is supported by plates whose upper surfaces have grooves extending in the direction of movement of the belt. Passages through the plates for the supply of lubricant open into these grooves.

Abstract: In a rotary drum vacuum filter, the drum sectors are connected by conduits to apertures in a rotary valve member on the drum which is opposed to a fixed valve member. The valve members thus control supply of vacuum (to cause suction filtering) and pressurized gas (to blow the cake of filtered material from the filter) to the drum sectors as the drum rotates. In order to eliminate the time delay between suction and blowing which is needed in order to allow the conduits to purge, another group of conduits is provided, having one-way valves adjacent their connection to the drum surface; this group is used only for blowing. The different groups of conduits are connected to apertures of the rotary valve member at different radial distances from the axis of rotation.