Cost analysis of soot blower use for boiler maintenance at sasol secunda

This paper presents cost analysis for maintenance in the steam plant department of Sasol in Secunda, South Africa, based on weekly boiler outage and general boiler breakdowns. All maintenance and contributing factors during a General Overhaul (GO) for a period of 48 months maintenance plan are carefully analyzed in this paper. The current cleaning technology which uses soot blowers was found to be the main contributor to the high costs due to its failure when the boiler is running, causing leaks and erosion on boiler tubes. As a result, there is a significantly high cost on superheater tubes with a variance of R29 704 191.18 from a budget of R50 919 502.53 in 14 days of a 90 days GO. The cost of soot blower repairs also exceeds the budgeted amount of R1 000000 by R428 884,73 in variance in 14 days of the GO. The results of metallographic examination of the tube used is presented in this paper. Based on this analysis a new maintenance method using an acoustics approach is proposed in this paper. This approach can either work hand in hand with the soot blowing technology currently being used for the existing design of boilers to minimize the exposure of the tubes to pressure hot air or be used independently for a whole new design of boilers.