Product/Service

Ross SLIM - Powder Induction Technology

SLIM
Every process engineer who has worked with powders such as fumed silica, CMC, guar, xanthan, carageenan, alginates and other thickeners has come face to face with one of the toughest challenges in mixing. Many of the powders that are most often used in the process industries are infuriatingly hard to wet out and mix. They will float for hours on the surface of a liquid batch.
Every process engineer who has worked with powders such as fumed silica, CMC, guar, xanthan, carageenan, alginates and other thickeners has come face to face with one of the toughest challenges in mixing. Many of the powders that are most often used in the process industries are infuriatingly hard to wet out and mix. They will float for hours on the surface of a liquid batch.

Even with vigorous agitation, they'll sail in circles on the slopes of a vortex and resist being drawn down into the batch. Once submerged, they form agglomerates that continue to resist being separated and dispersed.

In-line mixing systems are designed to break down these agglomerates and wet out the solids. But many systems designed for powder induction actually create more problems than they solve. Especially in first-generation induction systems that combine a pump, eductor and rotor/stator mixer, clogging and maintenance problems can be unrelenting – while the mixing process slows to a crawl.

The total cost of mixing hard-to-disperse powders – considering all of the process-line delays and maintenance costs that these powders cause in the process industries is enormous. But today, many process engineers are looking at these powders from a new perspective. Precisely because powder induction is often the cause of bottlenecks, excessive maintenance costs and downtime, it also represents a great opportunity. The quest for a new way to mix and disperse lightweight powders began as an effort to solve one of the oldest challenges in mixing. But the result turns out to have much greater importance than that. By solving numerous production problems at once, the new SLIM (Solid/Liquid Injection Manifold) technology for high speed powder induction offers significant gains in overall production and profitability.

-A drastic acceleration in the mixing process provides a real increase in capacity  without having to finance additional lines, equipment upgrades, or construction. -Eliminating the costs associated with frequent clogging produces an immediate reduction in operating costs (maintenance and spare parts inventory). -In many cases, the new powder induction technology also produces an unexpected dividend –a measurable improvement in end-product quality, because the dispersion is both faster and finer.

Powder induction shifts into overdrive. In the SLIM system, solids are combined with the liquid flow at precisely the point where positive mixing takes place. A specially modified rotor/stator generator equipped with Progressive Spiral Porting creates a powerful vacuum and draws the powder directly into the high shear zone, where it is instantly dispersed into the liquid stream.

The rotor/stator generator in the SLIM system draws a large volume of powder into the high shear zone, where it is simultaneously combined and mixed with the liquid stream (blue). Because the apparent viscosity of pseudoplastic (shear-thinning) materials drops in the high shear zone, these materials can tolerate heavy solids loading – reaching viscosities up to 100,000 centipoise without clogging.

The SLIM technology for high speed powder induction is being used today in many plants to achieve extremely high induction rates with many powders that are notoriously hard to disperse.

Powder injection prevents "dusting' and lowers the risk of explosion. By preventing dust from escaping into the plant atmosphere, the SLIM system eliminates a significant respiratory hazard and lowers the risk of explosion in the plant. Dust has virtually no opportunity to escape into the air, because the powder is mixed directly into the liquid stream in a closed system.

Charles Ross and Son Company