Cement silo’s can come in many different sizes but are typically filled by a 4″ or 5″ fill pipe.  Some high production concrete batch plants can have multiple cement fill pipes feeding the same silo.  The cement is transferred by a pneumatic blower, and depending on the blower size will determine the amount of cement that will be transferred per minute.  Although you might have the largest blower available, the transfer speed will remain slow if the dust collector is not sized to handle the C.F.M.  If the collector is to small, then the air cannot move efficiently into the silo and thus will slow down the transfer speed.  A good reference is the following chart;

Fill Pipe C.F.M.
850 CFM – Truck mounted blower
1,250 CFM – 60 H.P. blower
1,800 CFM – 75 H.P. blower

You can download the Cement Silo Collector specs from the manufacture to confirm the proper sizing of the collector to confirm the CFM.

Under sizing the silo collector can lead to the collector or cement silo roof being blown off.  Cement silo’s are typically designed to 3 PSI, and if the pop-off valve is not properly functioning, the silo can become over pressured and damage your equipment.