Silo Top Filter
Silo Top Filter is a cylindrically shaped dust collector for venting of pneumatically filled silos. The stainless steel body contains vertically mounted, Silo Top Filter elements.
Dust filtration is based on elimination of extremely small solid particles from a certain volume of air. This is achieved through use of a filter made from fabric or non-woven spun-bonded materials which allows air to pass through but is able to withhold the dust particles. To avoid clogging, the filter medium must be cleaned regularly. Divided into two families of round and polygonal filters, each group includes a variety of choices and options. The round dust collector range includes versions with weather protection cover, suction fan or a flange connection for an existing fan. The filter media are cleaned either by mechanical vibration or by a compressed air jet. Depending on the type of dust and the application of the unit, round filters are equipped with either cylindrical bags, elliptical bags or with cartridges, the latter offering the most favourable filter surface to volume ratio. The filter media itself can be made of needlefelt, different qualities of plain or surface treated non-woven polyester in standard or antistatic version and of various other materials, again depending on the type of dust to be filtered. In this case the dust source consists of a moving mixture of powder and air pouring into a collecting hopper. On arrival inside the hopper the air must be allowed to escape, otherwise the hopper would burst. On top of the air outlet a round filter with weather protection cover is installed in order to hold back the dust. The contaminated air is blown into the filter body. While the dust settles on the outside of the cartridges, the air penetrates the filtering media and escapes through the clean air outlet at the top of the unit. To keep the media clean, groups of cartridges are cleaned alternately by compressed air jets shot inside the cartridges. An electronic panel controls both the sequence and the length of the intervals at which the solenoid valves fitted on top of the air distributor modules let air out of the externally mounted pressure tank. This so-called reverse air jet passes from inside the cartridges through the media removing the layer of dust deposit on the outside of the cartridge elements. The dust particles fall back down into the hopper. The great advantage of the air jet cleaning system, compared to mechanically cleaned filters, is that it is possible to clean the filter while it is working. Consequently, air jet filters become an obligatory choice for continuous operation.