pelletroneurope GmbH

DeDuster®

DeDuster® Removes Electrostatic Charged Dust

Pneumatic conveying of plastics pellets and regrind generates fine dust particles due to friction and velocity. Plastics are good insulators of electrical current, and can build a reasonably high potential charge by the conversion of mechanical energy to static electricity. Due to electrostatic charging, the dust particles stick to the pellet surfaces. These dust particles can cause various unwanted side effects at the molding or extrusion process, such as black spots, blurry surfaces, weak spots and others. Therefore, this dust should be removed before processing of the pellets.

Pelletron has developed various types of DeDusters® for removal of the electrostatic dust. All DeDusters® are equipped with electromagnetic coils that generate a magnetic flux field. One or more electromagnetic coils are located at the product inlet or outlet of the DeDuster®, which produce a low level electromagnetic flux field that covers the entire cleaning area, called wash decks. The wash decks are provided with a series of slots and holes. Pressurized wash air flows through the slots accelerating the pellet toward the end of the deck into the venturi chamber. The holes create jets of air lifting the pellets, and release the dust, lifting it upward. This combination of electromagnetic flux field and air flow effectively removes fines. Pelletron offers DeDusters® in sizes 5 kg/h up to 100 t/h. DeDusters® build very low and can be installed easily on top of IMM’s, Extruders or under silos.

Pellbow®

In traditional long radius elbow installations, the pellets slide along the elbow wall at a high velocity. The strong centrifugal forces press the pellets against the outer metal surface. This causes friction which creates heat that melts the outer layer of the pellets, resulting in a thin film build-up along the surface of the wall. This build-up eventually breaks loose, forming unwanted streamers and fluff that lead to product contamination. Abrasive materials wear out the elbow walls quickly due to these high frictional lorces. The Pellbow® is especially designed to minimize damage to the elbow and the conveyed product.

Pellcon3™

Pellcon3™ – A New Economical Pneumatic Conveying Process

Dilute Phase and Dense Phase conveying solutions are established technologies. Investment costs for dilute phase is low, but due to the high conveying velocity, the friction in the conveying pipe is very high and consequently creates a high amount of fines, dust and streamers, resulting in loss of product due to high fines content. Installation of Dedusters® are necessary to remove these fines. In order to avoid the fines problem, Dense Phase conveying systems were installed for large scale systems to reduce the velocity and the damage to the resins. However, Dense Phase conveying systems are not dust free and create very fine dust. This fine dust accumulates in silos and contaminates resins before packaging. Consequently, installation of DeDusters® in Dense Phase systems is a common practice. The investment costs for such systems are very high, compared with Dilute Phase. Pelletron developed a new economical solution for material handling, pellcon3™. The process consists of STRANDPHASE® conveying in combination with Pellbows® and Dedusters®. STRANDPHASE® minimizes the friction and degradation of the product during pneumatic conveying. The pick-up velocity is in the range of 15m/sec and the terminal velocity does not exceed 25m/sec. The medium product to air ratio is in the range 5-20 to 1. System design pressure is depends on the lengths of the conveying line and type of product and is in a range of 0.5 to 2bar. The Pellbows® avoid the creation of streamers and the DeDusters® remove the remaining dust.