HRD | Rapid Dryer


Thermally-mild drying

minimum material retention time

Thorough water evaporation

without overheating the material


compact, rugged



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HRD Rapid Dryer
HRD Rapid Dryer

The HAZEMAG HRD Rapid Dryer is a highly efficient, field-proven dryer which combines the advantages of short-time drying and uniflow drying. With the material to be dried turned mechanically, with agitator paddles, and a simultaneous flow of hot gas through the material, gentle thermal drying is possible in a short time.

Thermal drying (water vaporisation) in the HRD Rapid Dryer is suitable for use in diverse applications across a wide spectrum of materials including: Clay and loam, limestone chippings, pozzolana, iron ore, aluminium hydroxide, gypsum (natural, chemical, flue gas), fluorspar and bauxite.

These materials mostly comprise moist filter cake (25 – 30% moisture) or pasty products, and must be dried to specific moisture values which can be achieved by appropriate design of the rapid dryer.

Thermal Drying
Thermal Drying

The thermal drying (water vaporisation) in the rapid dryer provides for diverse application in a wide spectrum of materials including: Clay and loam, limestone chippings, puzzuolana, iron ore, aluminium hydroxide, gypsum (natural, chemical, flue gas), fluorspar, bauxite, etc.

These materials mostly comprise moist filter cake (25 – 30% moisture) or pasty products and must be dried down to given values of moisture, defined by following steps of the material processing.

Process / Procedure
Process / Procedure

Hot gas and feed material are passing the dryer in parallel flow. The feed material is mechanical agitated with the flow blades mounted on the two shafts. Therefore the material is optimally broken up and dispersed. This results in a thermally-mild drying within short time, without overheating the material and thereby causing material damages.

Generally, drying gases are provided by a hot gas generator fuelled with oil or natural gas. The hot flue gas temperature is between 500°C and 800°C.


The rapid dryer consists of frame, housing lower part, housing upper part, hot gas nozzles, exhaust gas nozzles and drive units.

In the housing lower part two rotating agitator shafts are assembled. The dryer is partially protected against wear with a lining in the interior compartment. The agitator shafts are equipped with throw arms on which throw blades are bolted. The shaft bearings at the feeder side are cooled with water, if required. Internal height adjustable compartment walls control the dwell time of the feed material.

  • Convection dryer utilizing hot gas as drying medium
  • Minimum material retention time and high heat efficiency
  • Material beneficiation achieved by drying / de-agglomeration
  • Extremely intensive heat exchange between gas and wet material
  • Compact, rugged design
  • Drying medium normally achieved by the flue gases from an oil-fired or gas-fired hot gas generator



Model Agitator Shaft
Max. Water
HRD 0630 590 x 3,000 670
HRD 0637 590 x 3,740 800
HRD 0837 780 x 3,740 1,400
HRD 0940 900 x 4,040 2,800
HRD 0946 900 x 4,640 3,800
HRD 1051 1,050 x 5,060 5,100
HRD 1061 1,050 x 6,080 6,600
HRD 1261 1,240 x 6,080 10,000/13,5000
HRD 1861 1,800 x 6,080 17,000/21,000
HRD 2170 2,100 x 7,040 27,000

* depending on feed material size distribution and density