Screening equipment is used to sort bulk materials with great attention to detail so that only the right particles end up in the final bulk stream. Unlike separating equipment, screeners sift materials mechanically. There are many different types of screening equipment that can be used in a bulk system.
The piece of equipment that is used depends on the industry and type of material being processed. Sometimes solids must be separated from solids, and in other applications liquids are removed from solids or vice-versa. While there is a long list of screening equipment, below are a couple of the most popular and common types among bulk material handlers.
Vibratory screeners are likely the most common piece of screening equipment in bulk applications. As the material moves across the screen, the machine creates vibrations that shake out small particles and remove clumps from the material. This is one of the most effective and efficient ways to separate materials by size. The size of the particles being sifted out can be determined by the pattern and shape of the metal screen and the rate of the vibrations. Vibratory screeners come in many different sizes and can process large volumes of material in certain applications. A linear vibrator is used to gently process dry goods by sifting them on a fine screen at a low frequency and in a stationary horizontal position.
High Frequency Screens
High frequency screens use intense vibrations to separate fine particles in applications like mineral processing. An electromagnetic vibrator connected to the surface of the screen controls the intensity of the vibrations as materials are introduced to the screen from a conveyor. High frequency screens can be used as a secondary screening measure to remove fine particles before or after the primary screening process.
While high frequency screens and vibratory screeners are the most likely to be found in a bulk material handling system, other types of screeners that may be used include: rod decks, disc screeners and star screeners. Each of these is best suited to sort larger individual objects rather than the fine particles or granules that are typically processed in most bulk facilities. In recycling and waste recovery centers, disc and star screeners are usually used to separate recyclable materials based on their size.
Screening equipment in bulk applications allows bulk material handling facilities to refine and purify their materials before they are packaged or shipped to distribution centers. With the right piece of screening equipment in a system, bulk handlers can process material in large volumes without compromising the quality of their product or allowing it to be contaminated by unwanted debris. Applications for screeners vary greatly and can include agricultural products, pet food, bulk baking ingredients, pharmaceutical batches and more. Screening equipment is easy to maintain and designed to operate continuously for high volume production in a busy bulk material handling facility. Some machines are even self-cleaning, meaning that they remove debris from the mechanism without the need for manual cleaning between production runs.