Determining the optimum size of a coal silo

Abstract

We have used computer simulation to help determine the optimum size of a silo for coal produced from the McInnes Mine in Pike County, Kentucky. The silo is used to store coal that is waiting to be cleaned. Previous experience suggested a silo capacity of 6000 tons. However, because of the complexity of the operation, we undertook a further study to evaluate the proposed size.

We used computer simulation to model the system and estimate the amount of lost coal production for different silo capacities. Based on the simulation results, we recommended a silo capacity of 7 500 tons to eliminate a potential bottleneck which could cause a loss of production.

The total study took two weeks, including model development and preparation of the report for model uses. The cost, including man-hour charges and computer charges, was approximately three thousand dollars.

We expect this study to provide savings of 1.5 million dollars, the difference in total life-cycle costs (including the cost of lost production and the initial investment) between the two proposed silo sizes. This cost/benefit ratio demonstrates the usefulness of computer simulation as a tool to solve real problems.