Mathematical modeling and reliability analysis for pellet manufacturing unit of a polymer section

Abstract

The study has been performed to know the availability of operating equipment in the industrial unit with mathematical modeling. The pellet manufacturing unit is a repairable system that can work satisfactorily after getting proper maintenance of a polymer section at naphtha cracker unit. It consists of various subsystems, namely steamer agitator, dryer, rotary feeders, feeders and screw feeder machine. The number of failures of a subsystem and its repair rate with respect to time are assumed to be constant. In current paper, system behaviour was analysed for knowing the actual availability in the unit with available maintenance data. The maintenance department’s history sheets were used to compile the data for all five subsystems. The probability-based approach of Markov process used for developing partial differential equations which are further solved by putting the sum of all the events equal to one. The steady state availability with known parameters were calculated to know the system availability. A critical analysis of subsystems has been carried out to enhance the performance of above said unit. It was observed that feeder subsystem was affecting the system availability more as compare to other subsystems. If failure rate increases, system availability decreases up to 7.0% and repair rate increases, availability increases up to 9.4%. That’s why maintenance priority should be given to this subsystem. The calculated results are communicated to the relevant authorities so that the right maintenance choices can be carried out on time.