Two main factors come into play when reducing cement silo filling times, dust collection and blower CFM. Cement silos can be round or rectangular and are typically filled by a 4-inch or 5-inch fill pipe. High volume batch plants will often have two fill pipes per cement compartment.
The cement, slag, or flyash is transferred by a pneumatic blower, the blower size will determine the amount of cement that will transfer into the silo per minute. Although blower size is a key factor to speed, dust collection plays just as important of a role. If the silo is unable to expel the air being charged into the silo to move the material, the load time per minute will be drastically reduced.
Dust collection should be appropriately sized to handle the CFM of the blower being used to transfer the material. It is important to know the manufacturer’s specifications before purchasing a new dust collector or a new blower. Buying a larger blower with higher CFM than your existing dust collector can handle will not increase loading speed.
850 CFM – Typical truck mounted blower
1,250 CFM – Typical 60HP blower
1,800 CFM – Typical 75HP blower
Under sizing the silo dust collector will not only reduce loading speed, but may lead to bigger problems. Typical cement silo is capable of handling 3 PSI of pressure. If you over pressurize the silo and the emergency pop-off valve fails, the silo could get damaged or even split the silo.