Abstract: A trailer mounts a first unit having an aggregate classifier and a pair of cyclones for pivotal movement between a generally horizontal storage position on the trailer and a generally vertical upright operational position on the trailer. A second unit having a second classifier and a second pair of cyclones is pivotally mounted on the trailer for movement between a generally horizontal storage position and a generally upright vertical operational position. In the storage positions, the units leave an open area in the middle of the trailer for storing and transporting ducts for use when operational. The duct work includes a riffle splitter "Y" duct for releasable securement to the aggregate inlets of the first and second classifiers in their upright position to provide a common aggregate inlet thereto. The ducts include a rectilinear duct for interconnecting the dust outlets of the cyclones when in their vertical operational position for channeling the dust to a baghouse.