In the furnace where the temperature is more than 1000° C, high alumina tubes are used as protection tubes for a thermocouple. With the vision of continues development by adopting the latest technique, Tempsens introduce use of HWT specially designed tubes with heavy wall thickness for some critical areas like furnace crown and bottom of a glass furnace.
HWT (Heavy Wall Thickness) Protection Tubes
In furnace Crown the thermocouple
We can take an example of thermocouple with double protection tube to understand above point
With Normal Tube
Outer Tube Dimension
OD = 24mm, ID = 18mm, Wall thickness = 3mm
Inner Tube Dimension
OD = 15 mm, ID = 10 mm, Wall thickness = 2.5mm
Total wall thickness for thermocouple using above tubes is calculated as 3+2.5 = 5.5mm
Now, we will consider HWT tubes as outer Protection
Outer Tube Dimension (HWT)
OD = 24mm, ID = 12mm, Wall thickness = 6mm
Inner Tube Dimension
OD = 10mm, ID = 6mm, Wall Thickness = 2mm
Total Wall thickness for thermocouple using above tubes is calculated as 6 + 2 = 8mm.
Here we can observe the increase in wall thickness by 2.5 mm i.e. 45% of overall thickness. There is no major difference in price, but one can observe the enhanced service life of a thermocouple.
