Conveyor Dryers and Calciners

Conveyor Dryers and Calciners

Continuous multi-zone, for minimum physical drying attrition. Low capacity <10tph


Conveyor drying uses a perforated belt to transfer feed materials through the dryer. Heated air is either passed under and through or over and through the belt and product bed before being reheated and re-circulated. Units are normally multi-zoned and may have differing airflow’s in successive zones. Additionally, each zone may use a different temperature profile and control. Saturated or close to saturated air is exhausted from the dryer via an exhaust duct.

Conveyor dryers’ range in capacity from 100 kg/hr to upwards of 10 tph depending on the operational parameters. A conveyor dryer can be configured in numerous ways to accommodate the processing requirements, ranging from single zone to multiple zones with varying temperature profiles as well as single pass configuration to multiple pass stacked configuration where space limitations dictated compactness.

  • Temperature profiles can range from as low as ambient condition up to 900oC depending on processing parameters.
  • Materials of construction can range from painted mild steel, through to various grades of stainless steel to special alloys depending on the processing environments and conditions.
  • Conveying platforms range from perforated plate driven on a chain and sprocket assembly to speciality weave meshes and cloth.
  • Heat sources range from steam, thermic oil, electric gas and liquid fuel burner systems.
  • All equipment is tailor designed to suit the processing requirements.


Manual, batch, automatic and continuous. Vibrators, oscillating feeders, gravity chutes

Feed Characteristics:

Large granules, agglomerates, pellets, preformed (extruded) products (pressure agglomerates), small solid particles, large solid particles, agricultural products. Low to high feed rates.

Heat Source:

Steam, electrical, coal, liquid fuels, or gas.


Mostly Direct. Flow can be through the bed (under to over, over to under, or both), cross, countercurrent or co-current. Indirect systems available for certain products.

Residence time:

Highly Controllable. Residence time can be altered by varying the feed and discharge rates affecting the bed depth. The belt can be slowed and modulated.


Normally central induced. Re-circulating fans used in each zone. Exhaust connected to a common header

Dust Collection:

Typically little required. For fine product, a central baghouse is sometimes used.


PLC control for each zone, infrequently solid-state controllers. System controls on above bed temperature. Can modulate energy.


Very intimate contact with air/gas stream.
Multiple zones offer flexibility for temperature and process control
Excellent transfer of energy
Can vary flows between zones
Gentle handling of product
Self-contained with distributed foundation loading
The unit can have an integral cooling section.


High-temperature units can be troublesome
The heater can clog on carryover
Belt tracking can be problematic