chapter  12
22 Pages

## Leakage and gob flows

In establishing a ventilation network model of a longwall coal mine, it is natural to place a high emphasis on the modeling of the measurable main airways. These areas include main intake and returns, belt lines and the headgate, longwall face, and tailgate.Areas difficult to quantify, such as the gob and bleeder systems, are often modeled simplistically. However, these areas of the mine can be a critical component of the overall ventilation system.An inaccurately modeled bleeder system can result in under or overestimating the bleeder efficiency. This in turn may result in an unreliable base model.