Adding liquid to a powder is not simply a “pour and mix” operation.
Whether the objective is coating, dedusting, or granulation, the real challenge is achieving uniform liquid distribution without creating wet spots, sticky “mud,” or large lumps that are wet on the outside but remain dry inside.
Several engineering factors determine the success of the process:
🔹 Particle Size & Surface Area
Fine powders have significantly greater surface area available for liquid absorption. Particle Size Distribution therefore plays a critical role in determining the liquid capacity of the blend.
🔹 Atomization & Powder Movement
Liquid should be introduced in a controlled spray of suitable droplet size into a powder bed that is in continuous, intensive motion. Simply pouring liquid onto a static powder can quickly create wet spots, lumps, and paste.
🔹 Viscosity & Temperature Control
Highly viscous liquids may require heating, dilution, or an adapted injection system. Heating the complete feed line up to the nozzle can be essential to prevent viscosity increase and nozzle blockage.
🔹 High-Speed Choppers
Choppers can break existing lumps, de-lump newly formed agglomerates, and increase the available surface area—allowing higher liquid injection rates and potentially shorter mixing times. However, the heat generated by the chopper must also be considered in the process design.
🔹 Working Volume & Void Space
The mixer should not simply be filled to its geometric capacity. Adequate free space is necessary to allow continuous movement and exposure of fresh powder surfaces to the liquid.
The key principle is simple:
Every drop of liquid must meet the right particle, at the right time, in the right place, and at the right temperature.
Successful liquid addition is therefore a combination of particle science, injection engineering, mixing dynamics, viscosity control, temperature management, and proper mixer selection.
What challenges have you experienced when adding oils, binders, extracts, or other viscous liquids to powder blends?
More information, contact Energetic Sun: Tel 095 8562473, Email sales@energeticsun.tech