Trommel Screen Machine: Importance, Advantages, and Working in Paper Making

In the pulping process of paper making Trommel Screen machine is used for reject handling and fiber recovery from pulp slurry containing lite particles larger than 8-10mm rejected by the secondary screen after pulper. Trommel Screen is typically installed in the initial stages of the process to remove non-fiber particles like plastic and other contaminants from the pulp mixture ensuring no loss of valuable fiber.

Construction of Trommel Screen Machine:

Drum:

The main component of the trommel screen is a cylindrical drum, usually made of steel or stainless steel. The drum is mounted horizontally or inclined at an angle. It rotates on its axis driven by a motor or gearbox.

Perforated Screen with a Welded Helical Screw to its inner diameter:

The drum is perforated with holes or slots of customised sizes. The hole diameter and pattern choice depend on the desired classification and separation efficiency. The size of the perforations determines the maximum particle size that can pass through the screen. The helical Screw of same length as Perforated Screen is welded to an inner diameter of the perforated Screen drum.  As the drum rotates in a circular motion, the material inside the drum moves forward with Crests of helical screws.

Trommel Perforated Screen

Frame and Support Structure:

The drum is supported by a sturdy frame or chassis, typically made of steel. It provides structural integrity and stability to the Trommel Screen.

Support Rollers:

The drum is supported by a series of support rollers or trunnions, which facilitate the smooth rotation of the trommel screen. These rollers are often adjustable to maintain proper tension and alignment of the drum.

Drive System:

A motor or gearbox is used to provide rotational motion to the drum. The drive system should be capable of controlling the rotation speed and direction of the Trommel Screen machine as needed.

Water Spray Systems:

The spray system consists of multiple high-pressure water showers mounted inside the Perforated screen drum is a potion in that all the large-size particles get washed efficiently leaving fiber to water.

Working Principle of Trommel Screen Machine:

In Paper Manufacturing, the Trommel Screen machine is mostly used in recycled paper mills. The recycled paper as raw material contains plastics and tapes, a lite material called Lite Rejects in Paper Manufacturing Process.

The plastic lite particles get rejected from secondary screens and the pulp slurry goes through acceptance for further process. Fibrous materials, which are valuable for sustainable manufacturing also must be on the lite particles rejected. Hence the fiber must be recovered from this rejection before it is removed from process. The Trommel Screen is designed for fiber recovery from lite particles.

Trommel Screen Pulper Cleaning Systeam

Reject from the secondary screen is an inlet to Trommel Screen. In cylindrical drum lite reject material get efficiently washed due to water spray from high-pressure showers and Cataract motion of particles in drum due to its circular motion.

The Perforated Screen drum is also can installed in a Inclined position keeping its inlet in a lower position and reject it to the higher position, this mechanism insures that lite material washed efficiently and for a sufficient time.

While the lite reject is being washed, due to the circular motion of drum helical screw, it directs the lite particles towards the reject end of the Trommel Screen this reject is final reject containing plastics and other non-fibers particles finally dropped out from the pulping process. While the fiber on lite reject goes to the accept of trommel with water through the holes or slots of Perforated Screen drum. The accept from Trommel Screen, which is of a low pulp consistency goes back to pulper chest for further process.

Importance of Trommel Screen Machine in Paper Making:

By employing the Trommel Screen machine, up to 10% of Fiber can be recovered from reject of a Secondary Screen in Pulping loop of Recycled Paper Manufacturing.

Advantages of Trommel Screen Machine:

1. Efficiency: The rotating action of the drum helps to agitate and separate particles, ensuring thorough screening and separation.
2. Versatility: Trommel screens can be used for various materials and applications, making them a versatile screening solution.
3. Customization: The size of the perforations or mesh, drum dimensions, and inclination angle can be adjusted according to the specific requirements of the material being screened.
4. Low maintenance: Trommel screens have a relatively simple design with few moving parts, making them easy to maintain and operate.
5. Scalping and cleaning: Trommel screens can effectively remove contaminants and perform scalping (removal of oversized particles) and cleaning of the material simultaneously.

Applications Other than Paper Industry where Trommel screens working principle is used:

Mining and Mineral Processing :

In mining and mineral processing operations, Trommel Screen machine play a crucial role in material classification, separating valuable minerals from waste rock, and preparing ores for subsequent stages of processing.

Waste Management and Recycling :

Trommel screen machines are extensively used in waste management and recycling facilities. It efficiently separates different types of waste materials, such as plastics, paper, glass, and metals, facilitating recycling processes and reducing landfill waste.

Construction and Demolition :

Construction and demolition sites generate substantial amounts of debris and waste materials. Trommel screen machines aid in sorting and segregating these materials, allowing for efficient recycling, reuse, or appropriate disposal.

Composting and Organic Waste Processing :

In composting and organic waste processing facilities, Trommel screen machines help separate organic matter from composting materials. This ensures the production of high-quality compost by removing contaminants and achieving consistent particle size.

The Trommel Screen machine is a vital component in the pulping process of paper making, specifically in the recovery of valuable fiber from rejected pulp slurry. Its efficient design and working principle allow for the removal of non-fiber particles, such as plastics and lite contaminants, while preserving the valuable fiber for further processing. The machine’s construction, including the perforated screen drum, helical screw, frame, support structure, and drive system, ensures reliable operation and easy maintenance.

The importance of the Trommel Screen machine in the paper industry cannot be overstated. By utilizing this technology, paper manufacturers can recover up to 10%. The machine’s advantages, such as high efficiency, versatility, customization options, low maintenance requirements, and the ability to perform scalping and cleaning simultaneously, make it a valuable asset in papermaking and other industries.

Moreover, the Trommel Screen machine finds applications beyond the paper industry. Its working principle is utilized in mining and mineral processing operations for material classification, waste management and recycling facilities for waste separation, construction and demolition sites for debris sorting, and composting and organic waste processing facilities for organic matter separation. These diverse applications showcase the versatility and effectiveness of the Trommel Screen Machine in various industries. Overall, the Trommel Screen Machine is a reliable and efficient solution for screening, separating, and recovering valuable materials. Its widespread use in paper-making and other industries demonstrates its effectiveness in optimizing processes, reducing waste, and promoting sustainable practices. With ongoing advancements and innovations, the Trommel Screen Machine continues to play a significant role in enhancing productivity and environmental stewardship across different sectors.