US 5,291,876 AGranted

Feed hopper for providing preheated aggregate material

AssigneeAstec Industries, Inc.

InventorJohn Milstead

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Abstract

An apparatus for feeding preheated aggregate material, such as for the production of asphalt. A feed hopper includes a heater within its interior and positioned adjacent a slotted discharge opening at the lower end of the hopper. A tent-like cover is positioned above the heater to deflect aggregate material from contacting the upper portion of the heater and to transfer heat to the aggregate material in a uniform and efficient manner. The heater may preferably be a gas-fired radiant heater extending lengthwise parallel to and for the full length of the slotted discharge opening. A series of hoppers may be arranged in side-by-side relation and a common conveyor positioned beneath the individual feed conveyors of each hopper to direct the preheated aggregate material to a subsequent processing apparatus, such as a drum mixer or other dryer, used for the production of asphalt.

Claims13

Dependent claims

An apparatus for feeding preheated aggregate material, comprising:

a feed hopper having opposite upper and lower ends, said upper end being open and adapted to receive aggregate material therein, said lower end having a rectangular lengthwise extending discharge opening adapted to feed aggregate material therethrough;
an elongate gas fired radiant surface heater having an upper portion and a lower portion, said heater positioned within said hopper adjacent said lower end and adapted for preheating aggregate material prior to the aggregate material passing through said discharge opening, said heater extending lengthwise generally parallel to and above said opening and for substantially the full length of said opening;
and
a cover positioned above and in spaced-apart relation from said heater and adapted for shielding the upper portion of said heater from direct contact with aggregate material, said cover, said heater, and said lower end of said hopper being dimensioned and positioned so as to allow the lower portion to have direct contact with aggregate material moving past said heater and toward said discharge opening.

1 more element

Dependencies are inferred from the claim text.