Image Number 14 for United States Patent #6929393.
An asphalt production plant includes an asphalt binder storage tank, a mixer for mixing asphalt binder and aggregate materials, an asphalt binder pumping system for conveying asphalt binder to the mixer and an asphalt binder metering system for controlling the rate of flow of asphalt binder to the mixer. The asphalt production plant also includes a cold feed proportioning system having a plurality of cold feed bins for holding aggregate materials, with each such bin having a discharge opening through which aggregate materials may be discharged, a cold feed conveyor system that extends from beneath the discharge openings for the plurality of bins for conveying aggregate materials to the mixer and an apparatus and system for adjusting the relative proportions of aggregate materials from each of the cold feed bins that are conveyed to the mixer. The asphalt production plant also includes an aggregate sample dryer for removing volatile components from a sample of aggregate materials and an aggregate sampler for obtaining a sample of aggregate material from the cold feed conveyor system and depositing such material in the aggregate sample dryer. A preferred embodiment of the production plant includes an asphalt binder calibration tank, an oven assembly for removing asphalt binder from a sample of asphalt, an asphalt sample collector, an asphalt sample conveyor assembly for conveying a sample of asphalt to the oven assembly and an aggregate gradation assembly for determining the gradation of a sample of aggregate.