Tophat Furnaces


Thermopower Furnaces was established in 1968 on the design and supply of the electrical Tophat furnace to the thriving ceramics industry of South Africa. Tophat furnaces consist of two modules, a fixed base and a movable lid (Tophat). The principle is that the furnace is moved to the load and not vice versa. The base is loaded with product after which the Tophat is lowered to form a seal with the base. Tophats are used extensively in the ceramics industry as well as the heat treatment industry. Tophats require an overhead hoist or crane for the raising and lowering of Tophat onto the base.

Convection Tophat Furnaces

Convection Tophat Furnaces operate at low temperatures from ambient to 650C. High temperature paddle fans or radial re-circulation fans are used to create a homogenous heating chamber with excellent heat transfer characteristics due to the high coefficient of convection heat transfer. Convection Tophats are thermally efficient with minimal heat losses to the surroundings coupled with excellent heat transfer into the load. Convection Tophats are well suited to low temperature heat treatment operations.

High Temperature Tophat Furnaces

Standard high temperature Tophat furnaces operate up to 1200C while special Tophats can achieve 1450C. A well heat-balanced Tophat provides an “infinite tunnel” effect achieving an even firing across the width, height and length of the load. Electrically fired Tophats have excellent temperature control allowing the close tracking of firing profiles or patterns. The accurate temperature tracking is core to the success of the Tophat in the firing of delicate ceramics.

Tophat Furnace Specifications

  • Controlled Atmospheres (Oxidizing, Reducing, Inert, Special)
  • Thyristor Fired, Solid State Relay Fired or Contactor Fired options available
  • Multi-channel Paperless Data Recorder available for firing history
  • Ramp/Soak PID Temperature control with Multiple Firing Patterns
  • Automatic Damping/Cooling optional
  • Single, Double or Triple Bases available for high volume operations (Firing, Cooling, Loading)
  • Hydraulic tilting base (for dropping the load into a quench pit) available.
  • Standalone Local Control  of the Tophat or Remote Control with a Plant PLC available
  • Heat Recovery is possible subject to the client’s operation. 


  • Firing of Ceramics
  • Firing of Refractories
  • Heat Treatment (Annealing, Tempering, Normalizing)