Solids handling equipment specialist, Ajax Equipment is supplying Hosokawa Micron Ltd with a hopper and screw feeder as part of a turnkey powder processing system designed for the pre-conditioning of potassium carbonate powder during agrochemical manufacture.
Ajax is providing a 5m3 hopper which will receive potassium carbonate powder from big bags. The batch held in the hopper will be measured by load cells, and discharged by a screw feeder into the process reactor. Potassium carbonate powder is a difficult to handle powder. It can be both ‘sluggish’ when stored and compacted, yet light and fluffy when aerated or loosely poured. In addition, it can be prone to caking. Therefore, mass flow is preferred as it avoids stagnant zones and secures flow through the smallest outlets.
Based on measured flow properties of the powder, Ajax Equipment has designed the hopper for mass flow with steep walls and a long slot outlet to the screw feeder. To serve such a long outlet, the screw feeder has a progressive pitch, Lynflow ribbon flights and stepped shaft. This ensures the entire hopper contents move in a mass flow pattern during discharge, achieving a smooth transfer of the powder at the rate of 200kg per minute. Both the hopper and screw feeder are gas tight, and the equipment is designed to comply with ATEX Zone 2 requirements.
“Given the nature of the powder we’ve designed the hopper with a V-shaped tapered bottom section to encourage mass flow during discharge. Of course the screw feeder has to fully serve the long length of the hopper outlet to avoid any stagnant zones, so we have to take a lot of care in selecting the geometry of the screw flights and shaft,” explained Eddie McGee, technical director, Ajax Equipment.
“We chose Ajax Equipment for supply of the hopper and screw feeder based on the successful use of their equipment in similar applications and their proven ability to design and manufacture hoppers and screw feeders capable of handling this type of powder,” said Kristien Barrett, Sales Manager, Hosokawa Micron Ltd.
For more information on Ajax Equipment hoppers and screw feeders visit www.ajax.co.uk.