Aggregate feed was conveyed to the drum’s feed end, first passing over a 4x12 scalping screen to remove any material over 25 mm. The RAP feed system was similar in design, except here the material enters the drum through a collar behind the flame and is heated indirectly by the aggregates. All of the aggregates used by this Gencor plant were supplied by the Dundas operation, with the exception of the RAP hauled from Lafarge’s Nebo Rd. (Hamilton) operation.

The plant’s 135 million Btu Gencor Ultra II long nose burner utilised number 2 furnace oil, atomized by compressed air for burning and stored in two 50 000-litre tanks. Two asphalt cement tanks (A/C) tanks held 114 tonnes of Petro-Canada’s PGAC 58-28 and 74 tonnes of PGAC 64-28.

Exhaust gases from the drum passed into knock out box, where coarse airborne material fell out of the air stream and was recycled back into the mix. Meanwhile, fine airborne dust was collected in the 76 000 cfm capacity low profile baghouse and either transferred to a 50-tonne mineral silo or back into the mix.

Finished product was stored in a 130- tonne product silo that incorporated an 8- tonne capacity weigh hopper in its bottom section. Trucks were typically loaded in six batches, depending on truck capacity. In a number of U.S. states, the loaded truck would be legal for road travel at this point, based on   the material weight recorded by this system. In Ontario, like most jurisdictions, the truck required a ticket from an approved scale, pulling forward in this case to Active Scale Manufacturing’s 60-tonne platform scale alongside the portable control room. The control room contained all the plant’s operating systems, including the Gencontrol 4 automatic burner control system, the BC 200 mix blending system as well as the SL100 loadout system.

At the time of the visit, the plant was producing Open Graded Drainage Layer (OGDL) at an average production rate of 275 tonnes/ hour, operating with a crew of five including loader operator.