How to properly size a dust collector.
There are two types of dust control systems; central and individual collectors.  The central dust control system vents the storage silos and the mixer into one dust collector.  Individual dust collectors vent each storage silo, batcher and mixer separately.  Before you can determine the best collection configuration, you need to account for all of the dust collection points.  It is also a good idea to overestimate your collector C.F.M. requirements to account for any loss of efficiency such as worn ducting or plant production (higher yards per hour and mix design sack content).

Recommended Fill pipe CFM capacities;
850 C.F.M. – Truck mounted blower.
1,250 C.F.M. – 60 H.P. blower
1,800 C.F.M. – 75 H.P. blower
200 C.F.M. - Cement Weigh Batcher
5,000 C.F.M - Mixer Truck or 12 yard Tilt Mixer
* Note - If Flyash or Slag is incorporated into your concrete batch plant, we suggest increasing the CFM by 10%

The positive and negative aspects of a central dust control system.
CON- Increased cost for larger central system.  Requires ducting and ducting maintenance to connect to all dust pick up points to the central vacuum area.
PRO+ Central maintenance.
CON- Collects 1 pound per yard which is all reclaimed as fly ash.
CON- Requires damper valves.

The positive and negative aspects of individual dust control systems.
PRO+ Less cost for smaller multiple systems.
PRO+ Individual collected material will not be cross contaminated with foreign material.
CON – Individual collector maintenance.
PRO+ Reclaim same material directly into silo.
PRO+ Collects 1 pound per 10 yards (Collected at mixer only) which is reclaimed as fly ash.
PRO+ Does not require damper valves.