Jet Mill — supersonic, contamination-free
The THOR-JM Series Fluidized Bed Jet Mill harnesses supersonic gas dynamics to deliver pure, contamination-free micronization down to the single-digit-micron and sub-micron range. With no mechanical grinding media, it is engineered to deliver pharmaceutical- and electronic-grade purity — eliminating the metallic contamination found in mechanical mills, a proven choice for abrasive, cohesive and heat-sensitive powders.
- Output
- D50 1 – 10 µm
- Mechanism
- Fluid energy
- Jet velocity
- Mach 1 – 3
- Grinding media
- None
Particles grind
themselves
Supersonic Laval nozzles fire inert gas inward, creating a turbulent fluidized bed where particles collide with each other — never the walls. An internal classifier wheel releases only on-spec fines and recirculates the rest. No grinding media, and so no metallic contamination from media wear.
- Final D50
- 1–10µm
- Jet speed
- ≤1000m/s
- Cooling
- Isothermal
- Wear parts
- None
What is a Jet Mill?
A fluidized bed jet mill is an advanced, fluid-energy grinding machine designed for the ultra-fine micronization of powders down to the sub-micron and single-digit-micron range (D50 from 1–10 µm). THOR by CI engineers the series to operate without any mechanical grinding media or physical screens.
This technology is the benchmark for high-purity grinding — producing sub-micron powders with no grinding media and no metallic wear, the preferred ultra-fine pulverizer for battery materials, specialty chemicals and advanced active pharmaceuticals.
Where Jet Mill sits on the particle-size scale
How it works
Gas does the grinding. Supersonic jets fluidize the bed; particles collide with each other; a classifier wheel decides what leaves.
Supersonic gas expansion
High-pressure gas enters via radial Laval nozzles and expands to Mach 1–3, forming supersonic kinetic jets.
Fluidized autogenous collision
A turbulent fluidized bed forms; particles accelerate and shatter on mutual impact — never touching the chamber.
Pneumatic classifying drag
Expanding gas rises, carrying micronized particles upward toward the dynamic classifier wheel.
Dynamic selection cut
The wheel rejects oversize back to the bed; on-spec fines pass through and exit to the collection cyclone.
Main components
Five core assemblies — built around purity, supersonic gas and precise classification.
Autogenous grinding chamber
Heavy-walled circular chamber lined with high-purity polyurethane, alumina ceramic or silicon carbide to prevent contamination.
Supersonic Laval nozzles
Precision-machined tungsten-carbide or sapphire nozzles converting high-pressure gas into supersonic kinetic jets.
Internal air-classifier rotor
High-speed ceramic classifier wheel that screens out oversized particles aerodynamically.
Digital variable-frequency drive
Electronic controller regulating wheel speed — letting operators adjust the D97 top-cut in real time.
Explosion-proof housing
Pressure-shock-resistant steel shell that contains spikes when grinding flammable or explosive powders.
Advantages & limitations
Where fluid energy is unmatched — and the auxiliaries it demands.
Advantages
Zero metallic contamination
Autogenous grinding and ceramic linings prevent metallic pickup — ideal for EV battery graphite and silicon anode materials.
Isothermal grinding (self-cooling)
Compressed-air expansion absorbs heat (Joule-Thomson), keeping the chamber cool and protecting heat-sensitive APIs.
Precise sub-micron separation
The integrated classifier wheel produces clean, narrow PSD curves with no coarse oversize fraction.
No mechanical wear components
No gears, pins or screens — virtually no mechanical maintenance and immunity to hard-material damage.
Limitations to plan for
Substantial auxiliary equipment
Needs a steady supply of oil-free compressed air — rotary-screw compressors, air receivers and refrigeration dryers.
High specific energy consumption
Compressing air for fluid-energy milling costs significantly more energy per ton than mechanical impact mills.
Strict feed-sizing limits
The fluidized bed can't take coarse feed — material must be pre-milled below 1.5 mm for efficient fluidization.
Milling, mixing & bulk handling
The THOR-JM Series runs under continuous negative pressure — no dust escapes into the factory atmosphere.
Hygienic feeder integration
Double-flapped sanitary rotary valves or loss-in-weight twin-screw feeders introduce powder without losing pressure.
Sub-micron cyclone receivers
Output is conveyed to multi-stage cyclones and pulse-jet baghouses with PTFE membrane filters that capture sub-micron particles.
Closed-loop gas circuits
For explosive or toxic materials, run nitrogen or argon in a closed recycling loop with continuous O₂ monitoring and makeup.
Technical specifications & model range
Six frame sizes. Final sizing is confirmed after pilot trials with your actual feed material.
| Model | Chamber diameter | Compressed air flow | Rotor speed | Avg capacity |
|---|---|---|---|---|
| TH-JM-150 | Ø160 mm | 3.7 – 7.5 m³/h | 6000 – 18000 rpm | 10 – 50 kg/h |
| TH-JM-300 | Ø250 mm | 11 – 18.5 m³/h | 4000 – 12000 rpm | 100 – 800 kg/h |
| TH-JM-500 | Ø400 mm | 30 – 45 m³/h | 2500 – 7500 rpm | 800 – 1800 kg/h |
| TH-JM-800 | Ø630 mm | 55 – 90 m³/h | 1600 – 4800 rpm | 2000 – 4000 kg/h |
| TH-JM-1000 | Ø800 mm | 100 – 160 m³/h | 1200 – 3600 rpm | 4000 – 7000 kg/h |
| TH-JM-1200 | Ø1000 mm | 160 – 250 m³/h | 1000 – 2800 rpm | 7000 – 10000 kg/h |
Specifications are typical and subject to change. Final sizing confirmed after pilot trials with your feed material.
Other platforms
The rest of the THOR family Compare or pair — air classifying is often integrated with a mill