How to Handle Sticky Powders...
Many of these powders are sticky and most tend to form dust. Layers of crusts and agglomerates build up at the wall of the vessel and other equipment installed inside the vessel. These agglomerates in a later process are very difficult to destroy and require a lot of energy and time.
The quality of the product suffers by a coarse defined dispersion and with the consequence of different quality from batch to batch. Because of the inefficient use of the raw materials much more raw materials than normally required to be added in order to achieve the desired effect. A part of the raw materials “disappear” as dust in the environment, exhaust systems and dust filter systems. In total, this results in high production and general cost.
Powder Wetting Machines and the Rotor-Stator-Principle
Different to the installations described above, the Conti-TDS powder wetting machine is installed outside and beside the vessel and connected via a simple piping system.
The basic liquid is circulated in a loop which creates a vacuum inside the dispersing chamber of the machine. This vacuum is used to induct powders dust- and loss-free, directly from bags, containers, big-bags, silos or even from a silo truck.
The powders are transported in a dense-phase without the need for false air, and are directly dispersed into the liquid under vacuum. Due to the vacuum, the entrained air is expanded, opening up the surface of the powder, ready for wetting. Simultaneously the surface of the liquid in the dispersing zone is also extremely expanded. Only at this point, the powder comes in contact with the liquid (see the picture on the left) and become wetted in a most efficient way. In this area, the shear gradient is about 1000 times higher compared to a dissolver.
Colloid Wetting and Foamy Surfaces
Due to the blast waves created during the pumping action the colloid wetting is completed. The micro air bubbles that stick onto the surface of the particles are separated, coagulated and will collect on the surface of the liquid as a layer of coarse foam, even in products considered difficult to ventilate.
Learn how to achieve “Ready Made” dispersed bulks on page 4!
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