ConJet® High-Density Bed Jet Mill

Efficient Air Jet Milling with controlled maximum particle size

The ConJet® High Density Bed Jet Mill combines a spiral jet mill with an integrated classifier wheel. This combination allows the ConJet® to produce materials with the highest fineness independent of the product load, and with higher throughput capacities. In the past, the fineness was controlled by adjusting the feed rate. Now, the integrated dynamic air classifier in the housing can be infinitely adjusted to guaranty exact and consistently reproducible product quality in this spiral jet mill.

Residue-free grinding and minimal build-up of material inside the machine make the ConJet® the ideal mill for a multitude of products, including high-quality products.

The compact design makes this machine very easy to maintain and clean completely when product is changed!



  • Finenesses from d97 2.5 µm to d97 70 µm (based on limestone)
  • Spiral jet mill for the fine grinding of soft to hard materials
  • Exactly defined maximum particle size through integrated dynamic air classifier
  • Variable setting of fineness independent of product load
  • Classifier wheel with exchangeable, simultaneously rotating immersion tube to achieve highest finenesses, unlimited adjustment
  • Gap between classifier wheel and fines outlet rinsed by gas for highest possible prevention of oversize particles
  • Classifier shaft seal rinsed by compressed gas to protect the bearings
  • Hinged housing door provides very good access for easy, fast cleaning and maintenance
  • Simple machine operation
  • Effortless product changes
  • High energy density as a result of rotating product bed, thereby up to 40% higher degree of efficiency, compared to a conventional jet mill
  • More efficient grinding (higher throughputs possible)
  • No residual material in the machine housing, therefore practically no product loss
  • Reproducible results
  • Optional designs available: pressure shock resistant, gas tight, wear protected
Grinding principle of the spiral jet mill with integrated classifier


Adhesives / Sealants


Ceramics / Glass


Pigments / Dyes

Ores / Minerals / Metals


Life Science



grinding of technical ceramics with ConJet




Typical toner products have a D50 in the range of 5 µm – 7 µm. NETZSCH Trockenmahltechnik GmbH entered the field of toner processing with the development of the CGS Jet Mill in the 1990’s followed by the CFS/HD-S High Dispersion Air Classifier a few years later.


As the global leader in particle-reduction machinery, NETZSCH offers the technology and machinery to provide true drug development solutions.


The ConJet® High Density Bed Jet Mill combines a spiral jet mill with a patented dynamic air classifier enables you to achieve high degrees of fineness, independent of the load on the gas flow.


NETZSCH Trockenmahltechnik GmbH, one of the global leading companies in the area of dry product processing, is part of the Business Unit Grinding & Dispersing of the NETZSCH Group. Customers profit from our comprehensive experience potential and our diverse machine program, ranging from laboratory- and production machines to complete production lines. Fine impact mills, classifying- and jet mills as well as fine-cutting mills and high-efficiency fine classifiers made by NETZSCH are mainly used in the application areas chemistry, inorganic materials/minerals, ceramics and life science for pharma- and food applications.

Application literature

Application literature

A new jet mill combines a spiral design with a patented dynamic air classifier wheel to achieve optimum levels of fineness and throughput.

Application literature

The high-density bed jet mill represents an advanced development of the spiral jet mill. Its core feature is the integration of a dynamic air classifier at the centre of the grinding chamber. This enables optimal independent setting of the grinding fineness and efficiency. In addition, the circular motion of the material ground in the grinding chamber and the air classifier restricting product discharge from the grinding zone result in a very intensive loading of the gas jets with the material to be ground. This leads to a considerable improvement in the mill efficiency, especially for the grinding of lightweight materials. The operating characteristics of high-density bed jet mills and fluidized bed jet mills are compared and finally, on the basis of this comparison, favourable applications for the new high-density bed jet mill are derived.

the new spiral jet mill with integrated classifier wheel

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Machine sizes with grinding air capacities of approximately 35 to 125 Nm³/h.

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Machine sizes available for grinding air volumes from approx. 50 to 12,000 Nm³/h.

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Available for separation limits from 2.5 to 60 µm (d97).

Machine sizes available for gas volume from approximately 350 to 2.600 Nm³/h.

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