How to select the correct furnace for your unique thermal process

Interested in the pros and cons of different high temperature industrial furnace technologies? Harper is here to help guide you through identifying the ideal system for your unique process considerations, material characteristics, manufacturing parameters and facility constraints.

The design of an optimized thermal processing line is a complex set of considerations and challenges. Your unique material deserves the attention of a uniquely qualified partner. Harper’s expertise is proven, as we have collaborated with customers on hundreds of installs worldwide, batch and continuous, from 500°C to 3000°C for a range of advanced materials.

Contact our experts at any time to discuss the ideal system for your advanced material process, or use the interactive chart below to guide you with basic information on Harper’s technologies.


Reactor TypeTypical Material ProfileMaterial Handling TransportVolumetric UtilizationHomogenity of ReactionTypical Production VolumeRelative Energy EfficiencyResidence Time
Rotary TubeIdeal for powder and bulk materials with good flowabilityVia rotating tube and angle of inclinationModerateHighModerateHighFor materials with Low residence times
Pusher / Roller HearthsUsed for powders, bulk materials and net shapes with flowability issuesTransport in saggers via PushersModerateModerateModerateModerateFor materials with Moderate to High residence times
Mesh / Strip BeltUsed for powders, bulk materials and net shapesVia mechanical beltModerateModerateModerateModerateFor materials with Low to Moderate residence time
Vertical Tube / SlotIdeal for powdersVia gravity or set by Rotary valve or augerHighModerateLowHighFor materials with Low to High residence times
Horizontal SlotIdeal for fibers with excellent flowabilityMaterial generally not in contact with furnace. Utilizes tension standsLowModerateHighHighFor materials with low residence times
Batch FurnaceIdeal for low production volumesSaggersLowLowLowLowFor materials with Moderate to High residence times
Fluid BedUsed for powders and pelletsGas streamModerateHighModerateHighFor materials with Low to Moderate residence times
MicrowaveUsed for powders and partsVia saggers, belts, or rotary tubeModerate to HighHighModerate to HighHighFor materials with Lower residence times


Harper’s range of experience across different applications allows us to deliver a unique solution for each customer, with precise control of temperature up to 3000˚C:

Applications Chart


Additional educational resources:

  • Get a tour of advanced Rotary furnace designs
  • See a complete Carbon Fiber process line in action