State the causes of failure of heating element.
Following of the different causes of failure of heating element:
i) Formation of hot spot: Hot spot on heating element is the point which is at higher temperature than remaining heating element portion. So there is possibility of breaking of heating element at hot spot.
ii) Due to oxidization: At high temperature material gets oxidized which may cause failure of heating element.
iii) Due to corrosion: If heating element is directly exposed to chemical fumes then there is possibility of rusting of heating element which causes failure of heating element.
iv) Mechanical Failure: Measure heating element alloy contain iron which is brittle. Due to frequent heating & cooling of heating element, it may break (fail) due to small mechanical injury also.