Tech Team · Kintek Solution

Heating elements can burn out due to a variety of factors including evaporation due to low vapor pressure, embrittlement, contamination, faulty wiring, and the formation of hot spots. Understanding these causes is crucial for ensuring the longevity and efficiency of heating elements in various applications.

Key Points Explained:

1. Evaporation Due to Low Vapor Pressure:

   • Mechanism: When a heating element is exposed to a vacuum or low-pressure environment, the material can evaporate if the operating pressure is below its vapor pressure. This evaporation reduces the cross-sectional area of the element, leading to burnout.
   • Prevention: To prevent this, heating elements should be made from materials with a lower vapor pressure than the operating pressure of the furnace. Using partial pressure atmospheres above the critical evaporation temperature of the element material can also help.

2. Embrittlement and Grain Growth:

   • Effect: Heating alloys containing iron can form large, brittle grains at high temperatures, making the elements brittle and prone to rupture.
   • Impact: This brittleness can lead to easy rupture during handling or operation, causing the element to fail.

3. Contamination and Corrosion:

   • Sources: Contamination can come from gases in controlled atmospheres, fumes from fluxes used in brazing, or oil fumes from heat treatment of contaminated components.
   • Consequences: These contaminants can lead to dry corrosion of the elements, reducing their lifespan. Corrosion can also cause small cracks, which over time can lead to burnout.

4. Formation of Hot Spots:

   • Causes: Hot spots occur when certain points in the heating element reach a higher temperature than the rest. This can be due to local oxidation, shielding by supports, or insufficient support leading to sagging and warping.
   • Effects: Hot spots increase local resistance and heat production, leading to breakdown of the element.

5. Oxidation and Intermittency of Operation:

   • Process: High temperatures cause the formation of a continuous oxide scale on the element's surface, which protects the inner metal. However, frequent heating and cooling cycles can cause this scale to crack and flake off.
   • Impact: This exposes fresh metal to oxidation, leading to increased local oxidation and the formation of hot spots.

6. Faulty Wiring:

   • Issue: Problems in the wiring of the furnace can lead to inadequate electrical power reaching the heating element.
   • Consequence: This can cause the element to burn out due to insufficient power or incorrect current flow.

7. Protection and Control Systems:

   • Measures: To prevent burnout, systems such as automatic temperature controls, overload relays, and fuses are used. These systems help manage the temperature and current flow, ensuring the element operates within safe parameters.
   • Importance: Properly functioning control systems are essential for the longevity of heating elements, as they prevent overloading and excessive temperatures.

By understanding and addressing these key points, one can significantly enhance the durability and performance of heating elements, ensuring they operate efficiently and safely in various industrial and laboratory settings.

Heating elements are the backbone of countless industrial and laboratory processes. From evaporation due to low vapor pressure to faulty wiring, understanding the challenges they face is crucial. At KINTEK SOLUTION, we offer robust solutions that tackle these issues head-on. Upgrade your equipment today to ensure longevity and efficiency. Don’t miss out on our specialized products designed to prevent burnout and enhance performance. Contact KINTEK SOLUTION now to learn how our expert solutions can transform your operations. Take the first step to reliability—reach out today!