Silicon carbide and silicon nitride tubes that protect the heating element or burner and pass its heat into the metal.
The element sits in the tube, the tube sits in the metal.
Everything the element makes has to pass through that wall.
An immersion heater tube saves energy in an aluminum holding furnace when its wall passes heat into the melt quickly and stays free of oxide, because buildup on the tube insulates the element from the metal. Blasch immersion heater tubes are made of silicon carbide (OXYTRON, OXYTRON 015XDII, NITRON) and silicon nitride (SINTRON), which combine high thermal conductivity with thermal shock resistance and low wetting by aluminum and zinc. Standard heaters cover 5 to 30 kW, and nearly any custom size can be cast.
An electric element or a gas burner sits inside a closed ceramic tube that is immersed in the molten metal. The tube is the barrier: it keeps the metal away from the element and carries the heat through its wall into the bath.
Heating from inside the melt puts the heat where the metal is, instead of heating the furnace atmosphere above it. How well that works depends on the tube: how much heat its wall conducts, and how clean its surface stays over months.
Every layer of oxide on a heater tube is insulation between the element and the metal, so a tube that aluminum does not wet keeps delivering the heat you pay for.
Properties that decide efficiency and life in the holding furnace.
Silicon carbide and silicon nitride conduct heat well, so less energy is lost on the way to the melt.
Aluminum and zinc do not wet the tube, so dross builds up slowly and life becomes predictable.
The tube survives heat up, charging and changes in metal level without cracking.
| Material | Type |
|---|---|
| OXYTRON | Oxide bonded silicon carbide |
| OXYTRON 015XDII | Latest generation of oxide bonded silicon carbide |
| NITRON | Nitride bonded silicon carbide |
| SINTRON | Silicon nitride |
Heaters range from 5 to 30 kW, with controls available on request. Tubes are made for horizontal or vertical installation, with cast-in flanges, O-ring grooves or custom mounting points, and with internal element holders or gas separators where needed.
Aluminum holding and dosing furnaces in die casting, and zinc galvanizing lines, where the bath is kept at temperature from inside.
In the same furnace, the temperature reading comes from thermocouple tubes in the same materials, and low pressure cells draw their metal through aluminum titanate riser tubes.
Silicon carbide or silicon nitride. Both conduct heat well and resist thermal shock; the non-wetting OXYTRON grades limit oxide buildup in aluminum.
Yes. The tube protects either an electric element or a gas burner, and gas separators can be built in.
Heaters from 5 to 30 kW and controls are available on request. Tell us your furnace, and an engineer proposes tube and heater.
Send the furnace, the alloy and the tube size you use today. A Blasch engineer proposes the material and the mounting.
