Re-crystallized Alumina & Mullite

Structure of Ceramic Pyrometry Tubes

Duralox 997 Recrystallised Alumina and MU140 / MW 70 Dense Mullite ceramic Pyrometry Tubes are fine grained, non porous and impervious.

Duralox 997 is high purity Alumina containing 99.7% Al₂O₃ and possesses good electrical resistivity as well as high thermal conductivity at high temperatures and can be used upto temperatures >1800°C (3272°F).

Material selection depends upon operating conditions and performance requirement such as temperature, atmosphere, sensitivity to contamination etc.

Mullite Grade MU 140 & MU 170 (3Al₂O₃ 2SiO₂) are excellent high temperature resistant ceramic composites having better thermal shock resistance than alumina, having low thermal expansion and good mechanical strength at elevated temperatures.

Following grade Mullite ceramic tubes are cost economical as compared to Duralox 997 and are ideal for use at high temperatures with good thermal shock resistance when application is less demanding.

Mullite MU140 is a dense composite of Mullite and glass formulation to provide the best performance in thermal shock and sag resistance at maximum operating temperature > 1400°C. Can be used suitably for many applications including rollers for roller hearth kilns where temperature is around 1250°C.

Mullite MU170 - This composition has a structure consisting of large proportion of interlocking micro crystals of Mullite for use at service temperature >1600°C, and is meant for specific applications. It is highly resistant to flux attack, relatively inert to Sulphurous and Carbonaceous atmospheres and has a high electrical resistivity.

Mullite MU170 is recommended for insulation of thermocouples when the service conditions are severe. Also it is ideal to use as combustion and furnace tubes including radiant heater tubes, rollers for high temperature (>1600°C.) roller hearth kilns, etc. Jyoti offers economically priced MU140 Mullite ceramic tubes with one-end-closed and both ends open, single and multi bore tubular insulators.

The most important properties of MU140 / MU170 grade Mullite ceramic tubes are imperviousness for long period, good rate of heat transfer, adequate refractoriness to prevent sagging and good resistance to thermal shock.