Appeal 2006-3058
Application 10/386,070
invention is said to provide improved production rates with greater economy
and efficiency of plant design and operation. Specification [0003].
Independent claim 20 is reproduced below:
20. A counter-flow drum mixer asphalt plant for producing asphaltic
product from aggregate and liquid asphalt, said asphalt plant comprising:
a rotatable cylinder having first and second ends with an internal
passageway communicating therebetween and serially providing zones
therein from said first end to said second end defined progressively as a
drying zone, a combustion zone and first and second stage mixing zones;
a support framework carrying said cylinder in a substantially
horizontal orientation; a drive motor mounted on said framework and
engaged with said cylinder to rotate said cylinder about the central
longitudinal axis thereof;
a primary aggregate feeder with a material discharge extending within
said first end of said cylinder to deliver aggregate material to said drying
zone of said cylinder whereby rotation of said cylinder transports said
aggregate material progressively through said drying, combustion and first
and second stage mixing zones to said second end of said cylinder;
a combustion assembly projected into the second end of said cylinder
and extending through said first and second stage mixing zones to said
combustion zone to generate a hot gas stream in said combustion zone to
flow through said combustion and drying zones toward said first end of said
cylinder in a countercurrent direction to the flow of aggregate material
within said cylinder in order to heat and dry the aggregate material within
said combustion and drying zones, said combustion assembly including a
burner head positioned at said combustion zone, a fuel supply connected to
said burner head, and a primary combustion air supply connected to said
burner head to establish a combustion flame within said combustion zone of
said cylinder;
a liquid asphalt feeder disposed within said first stage mixing zone for
delivering liquid asphalt to the hot aggregate carried from the combustion
zone into said first stage mixing zone to form an asphaltic composition;
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Last modified: September 9, 2013