Screening How to Remove Agglomerates: Sifter for Micron-Size Particles
You are looking for an equipment which is the ideal choice for continuous scalping of dry or moist materials, even those that tend to ball or agglomerate? This case study features a centrifugal screening device which combines high performance with easy maintenance.
Established in 1987 as the exclusive distributor of bromine-based compounds produced by the Dead Sea Bromine Group of Israel, Morre-Tec Industries of Union, New Jersey/USA is a leading producer of specialty chemicals and other products for the nutritional, food, personal care and biotech industries. With a 2,325 m2 facility designed to operate under ISO 9000-2008 and cGMP standards, the company also provides custom blending, grinding, and repackaging services for non-hazardous and food-grade chemicals and natural products.
One of the Morre-Tec’s services is a patented process for reducing solid particles to uniform micrometer size without damaging their crystalline structure. This “micronizing” process is used to produce a proprietary product called Micro-Phyte that is used to lower cholesterol levels in the blood. The material, a solid plant sterol, is insoluble in water, but once reduced to an average particle size of 3 µm it forms a stable emulsion that will not settle out.
“Soft Milling”: A Key Step for Particle Screening
A key step in the proprietary process is “soft milling” of the initial plant extract, which reduces incoming particles averaging 40 µm in diameter to particles averaging 2–5 µm. However, particles agglomerating into flakes on the walls of the vortex mill, and further compacting in the product collector, “were balling up and sitting on top” of the original circular vibratory screener, says Paul F. Caskey, Vice President, Administration and Operations. To solve this problem, Morre-Tec installed a Kason Centri-Sifter centrifugal screener that removes the oversize particles.
The plant extract is delivered to Morre-Tec facility in 907 kg bulk bags. These are gravity discharged into a horizontal feeder equipped with a dust collector to prevent valuable product from escaping into the atmosphere. The material is then fed by compressed air through an airlock into the micronization chamber.
How Vortex Milling Works
The patented micronization technology, licensed from Super Fine of Israel, is known as Vortex Milling. “Unlike jet milling, which relies on collision and abrasion to reduce particle size, the process creates rapid serial changes within a vortex chamber to replicate tornado-like conditions that cause the particles to fracture along their weakest fissure lines,” explains Leonard Glass, President of Morre-Tec Industries. “Since the particles never actually touch each other, they are reduced to their optimum size without being exposed to destructive forces that can affect crystal morphology.”