ethylene plants maintenance coast

[aimanaly]

i am working in very big ethylene plants 650000 t/year and we have that much money for the running maintenance coast for the furnaces,rotating equipment,heat echangers and compressors
my question what is the ideal or the normal running coast for this types of plants
and if there are some servay i can use it ,and it wiil be easy if it is avelable in the net by useful links,or magazines

 

[davidb]

An interseting question. The maintenance costs are not immediately available but you can use the following with some confidence. Ethylene furnaces are subject to a great deal of maintenance. Your design will be of great importance. For instance, are furnace tubes such that online decoking is possible? Some have stretched the tube replacement time to 5-7 years with proper operation and on line decoking. The total annual maintenance cost for this type of plant, with the state of the art maintenance systems and a well trained work force could be 1.5 to 2 % of ERV. A third of that will be spent on furnaces. A complete assessment is necessary to fine tune the maintenance costs and budgets.