Harper’s patented vertical furnace systems is our latest thermal processing innovation for a wide range of product feedstocks, particularly for materials requiring high temperature solid-solid and solid-gas reactions, such as carbides, nitrides, borides and refractory metal powders. This new system is a design alternative to other traditional furnace types, with the following advancements:
- Minimizes the opportunity for product sticking or gas-phase entrainment during processing
- Maximizes product uniformity and reaction time by minimizing or eliminating bulk bed effects
- Provides better heat and mass exchange between products and reactants for improved efficiency
- Limits heating and cooling requirements to the process material only – containment remains at temperature and the process material moves through it
In Harper’s vertical conveyor furnace, reactions occur more uniformly and quickly over the surface layer of material, and off-gassed material exits the process upwards and away from the product. The system’s specialized material movement limits the potential for overheating problems, such as melting/sublimation, sintering or excessive grain growth. In addition to the container-less nature of the design, thermal transfer between product and reactants significantly improves the power efficiency of the unit.
Product mixing concerns during reaction are also minimized given that the peak process temperature is encountered at the immediate top of the reaction bed. This reaction zone is continuously removed and replenished in a fountain-like manner, ensuring that the entire bulk of material is exposed to radiative heating and solid-gas interchange in a nearly-uniform manner. Because the material is not continuously agitated, there are also lower levels of fine powder entrainment.