Trommels and trommel screens are mechanical screening machines that are used to separate materials. They are often used in mineral and solid-waste processing industries. Additionally, they are used to remove fines from a given waste stream. A trommel consists of a wedge wire cylindrical drum that is usually elevated at an angle at the feed end.
How does recycling trommel screens work?
Material is fed into the trommel drum and is lifted up by the rotation and aerated as it falls back down. This action is repeated with each revolution along the length of the screening drum. Therefore smaller segments pass through the screen openings. In the meantime, larger fractions tumble towards its eventual exit at the rear of the trommel drum.
In conclusion, a trommel drum cylinder is used to separate materials by size. For example, they are sometimes used for separating biodegradable fraction of mixed urban waste or separating different sizes of crushed stone. Contractors may screen their site debris into two segments; a saleable topsoil for farms, nurseries and site-work, as well as rock cleaning for aggregates or landscaping work. In addition, this allows the contractor to resell their waste instead of incurring the cost of sending it for disposal.