Lifetime Evaluation of Electric Radiant Film Heaters

A theoretical expression is proposed for predicting the lifetime of electric radiant film heaters (ERFHs) based on parameters with values that can be determined using existing methods. The main ERFH-insulation elements responsible for the lifetime are determined: a conductive tape, conductive-tape bends, and points of contact of the conductive tape with supply wires. Ageing coefficients are obtained for these elements, and the polynomial dependences of the ERFH-insulation elements’ breakdown voltage rate on the main operating factors are determined. The Monte Carlo method is used to estimate the lifetime parameters. The MathCAD mathematical package is used for calculating and determining statistical characteristics of the ERFH element lifetime distribution with allowance for the random nature of the influencing factors, the results of which are presented as lifetime density histograms. The corresponding basic values of the gamma-percentile life of the elements and the ERFH as a whole are also calculated with allowance for the stabilization time. The obtained data make it possible to quickly assess the effectiveness of measures for ERFH design and quality improvement.