FD-type drum screens are filtering devices for removing solid pollutants in sewage, the so-called screenings. Drum screens are characterized by high resistance to fibrous contamination, plastic bags, rags and strings. The offered series of types has a capacity range of 12 to 2000 m3 / h.
FD drum screens include a number of amenities that facilitate handling and allow the separation of large amounts of waste. Their efficient operation requires rinsing with process water (e.g. with purified sewage) and removing the solid fraction to the outside.
The use of the best technologies enables the drum screens to be connected to other devices in one integrated system. These can be, for example, screening presses or sand traps, into which, after preliminary filtering, the mechanically pretreated sewage will be discharged. FD-type drum screens are made of AISI 304 stainless steel or, at the customer's request, of higher quality steel (with increased corrosion resistance). Depending on the needs, the equipment can be started automatically within the treatment plant or controlled manually.
The principle of operation of drum screens is very simple and does not require any intervention during operation. The sewage is directed to the inlet chamber, from where it is evenly distributed to the outer surface of the cylindrical screen retaining the screenings. The drum is equipped with slots with the clearance required by the user. On its outer surface, solid impurities larger than the gaps through which the purified water leaves the device are retained. Screenings collected on the surface of the drum are removed by a special plastic scraper, from where they are discharged externally for further processing, usually in a screening press attached to the drum screen, which compacts them and squeezes out the remaining water. You can also install a permanent scrap container or a screw conveyor that transports the screenings elsewhere. The drum screens themselves are rinsed with process water, usually with treated sewage, to prevent clogging during continuous use. This is by far the most effective method for the first stage of mechanical wastewater treatment.
The correct type of strainers employed determines the quick and effective cleaning, which is expressed in the parameters related to the throughput. The range of offered drum screens has a capacity of 12 to 2000 m3 per hour, which covers the needs of most industrial and municipal sewage treatment plants.