anything special about how you piped the vac intake and exhaust on the lid
Lid specs- Intake ( coal) 2'' pvc Exhaust to ( shop vac) 1 1/2" Bottom side of lid you'll need to create a vortec of air to remove coal dust. To achieve this place a 90 degree elbow on exhaust only.
do you have to move the intake on the coal pile around while it is filling the drum or does it stay buried in the pile?
Coal bin intake pipe is 2" that is buried about 3 ft into coal pile. You'll need to tweak this by adding (1/8) drill holes to topside of pvc pipe to allow air flow so it doesn't get air bound.