The air inlet scroll of a JACAN ACM air classifying mill is the lower annular air plenum, engineered to deliver uniform tangential airflow into the grinding chamber under negative pressure. Its geometry directly controls airflow distribution, particle circulation, thermal dissipation and mill stability.
1. Tangential Volute Profile
The scroll adopts a gradually expanding logarithmic volute shape. Process air enters tangentially rather than axially, creating a stable rotary air field around the grinding rotor. This tangential entry evenly distributes air along the full circumference of the grinding zone, avoiding local dead zones or airflow bias that would cause uneven particle classification and material buildup.
2. Integrated Annular Plenum & Flow Equalization
Inside the scroll chamber, built-in guide baffles and flow splitting ribs balance airflow velocity around 360°. The plenum evens out turbulence before air passes upward into the hammer-liner grinding gap. It separates main process air from feed material stream; material enters separately through the feed inlet, preventing powder deposition inside the scroll casing.
3. Wear-Resistant Lining Structure
The inner wall of the scroll is fitted with replaceable wear liners. Standard material is hardened steel; high-chrome cast iron or ceramic liners are used for highly abrasive minerals, battery powder and silica. Segmented liner blocks simplify maintenance, so worn sections can be swapped individually without removing the entire scroll housing. All joints are sealed to stop air leakage under vacuum operation.
4. Modular Flange Connection & Adjustable Air Duct
A standard PN10/PN16 flange is fitted on the scroll air inlet port. The inlet duct can be equipped with manual or pneumatic air dampers for continuous airflow tuning. Operators adjust air volume to modify particle residence time inside the grinding chamber, matching different target fineness requirements. For inert gas protection versions, the scroll flange is upgraded for gas-tight sealing with PTFE gaskets.
5. Heat Dissipation & Anti-Caking Geometry
Smooth curved inner surfaces eliminate sharp corners and recess pockets to reduce powder accumulation. The incoming cool air flows upward through the scroll into the grinding zone, removing impact heat generated by hammer collisions. This built-in cooling function limits temperature rise, making the mill suitable for heat-sensitive materials such as resins, food additives and organic powders.
6. Compact Split Casing Design
The scroll assembly forms the base of the grinding chamber. It uses split casing construction for easy access during inspection and liner replacement. It can be disassembled independently without detaching the upper classifier housing. Explosion-proof ACM models reinforce scroll wall thickness and add explosion relief ports, while maintaining the original airflow geometry.
The ACM air inlet scroll features logarithmic tangential volute, internal flow equalizing baffles, replaceable wear-resistant segmented liners, tunable air damper and smooth anti-deposition curved surfaces. It provides circumferentially uniform rotary airflow, controls grinding zone residence time, removes grinding heat and keeps stable negative-pressure circulation for integrated grinding and classification.
