Funnel Fire



Thermal Failure Mode Analysis
Design Fault Investigation
Forensic Advisors

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Change of Working Conditions

A leading manufacturer of waste heat boilers and economisers engaged us as forensic advisors to investigate the increasing incidences of ship's funnel fires. Searches at Lloyds of London revealed little of direct interest, while inquiry into the clients' design procedures showed them to be entirely conventional.

Our analysis of reporting dates reflected a history co-incident with changing practices in ship operation - particularly the burning of increasingly heavy cuts of fuel oil and much-reduced times alongside.

The thermal failure mode analysis of current operating profiles showed uncombusted heavy oil fractions to layer a tacky film onto tubes and flue walls at the end of one operating cycle, attracting solid smuts from incomplete combustion upon the next cool start.

We demonstrated that temperatures would then rise during warm-through until the Lower Explosive Limit (LEL) was exceeded within the economiser tubestack, with ignition caused by sparks entrained in the exhaust gas stream.

Other examples include resolving the failure of a large perforated calender during commissioning of a new lofted absorbent tissue production line, thermal behaviour of rotor blades in military helicopters, and FMEA investigation of a new low pressure hot water boiler plant installed on a university campus.