摘要 |
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. |