US 4,229,109 AGranted

System for producing bituminous paving mixtures

AssigneeBoeing Construction Equipment Company

InventorBernard A. Benson

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Abstract

A closed loop system which includes (1) a drum mixer, (2) a heat source separate from the drum mixer for producing a heated gas, (3) intake and exhaust ducts which channel, respectively, the gas produced by the heat source to the intake end of the drum mixer, and the gas at the discharge end of the drum mixer back to one intake of the heat source, and (4) a fan for maintaining the flow of gas in the system. The gas produced by the heat source is between 700.degree. F. and 2000.degree. F. when it enters the drum mixer at its intake end from the intake duct. Graded aggregates and a bituminous binder are fed into the drum mixer at its intake end. The graded aggregates are mixed with the bituminous binder, in the presence of the heated gas, by rotational action of the drum mixer. The resulting bituminous paving mixture is discharged at the discharge end of the drum mixer, along with exhaust gas, a portion of which is channeled back to one intake of the heat source by the exhaust duct.

Claims14

Dependent claims

A partially closed system for producing bituminous paving mixtures comprising:

drum mixer means having an intake region in the vicinity of one end thereof and a discharge region in the vicinity of the other end thereof, said drum mixer means being operable, when fired, to produce a bituminous paving mixture at said discharge region;
means for introducing graded aggregate into said drum mixer means at said intake region;
means for introducing a bituminous binder into said drum mixer means at said intake region;
plenum means disposed at said intake region and arranged to substantially enclose the end of said drum mixer means at said intake region, the interior of said plenum means being open to the interior of said drum mixer means;
exhaust manifold means disposed at said discharge region and arranged to substantially enclose the end of said drum mixer means at said discharge region;
heating means, spaced apart from said drum mixer means, for producing a heated gas having a temperature in the range of 700 to 2000 degrees Fahrenheit;
said heating means comprising a burner, a combustion chamber having an outer periphery within said heating means and a heating means manifold substantially surrounding said combustion chamber;
said burner being arranged to produce an open flame for direction into said combustion chamber for a portion of the length thereof;
sealing means for sealing the ends of said heating means manifold to the outer peripheral surface of said combustion chamber;
said combustion chamber having a plurality of slot-like openings in at least a portion of its peripheral surface for permitting gas from said heating means manifold to pass into said combustion chamber through said openings;
first channeling means for receiving heated gas from said heating means and directing said heated gas to the interior of said plenum means;
second channeling means communicating with the interior of said exhaust manifold for directing a selected portion of exhaust gases within said exhaust manifold to the interior of said heating means manifold;
means for maintaining a flow of heated gas throughout said partially closed system.

10 more elements

A partially closed system for producing bituminous paving mixture comprising:

drum mixer means having an intake region in the vicinity of one end thereof and a discharge region in the vicinity of the other end thereof, said drum mixer means being operable, when fired, to produce a bituminous paving mixture at said discharge region;
means for introducing graded aggregate into said drum mixer means at said intake region;
means for introduing a bituminous binder into said drum mixer means at said intake region;
plenum means disposed at said intake region and arranged to substantially enclose the end of said drum mixer means at said intake region, the interior of said plenum means being open to the interior of said drum mixer means;
exhaust manifold means disposed at said discharge region and arranged to substantially enclose the end of said drum mixer means at said discharge region;
heating means, spaced apart from said drum mixer means, for producing a heated gas having a temperature in the range of 700 to 2000 degrees Fahrenheit;
said heating means comprising a gas-to-gas heat exchanger comprising a length of duct having a duct inlet and duct outlet at its respective ends;
a substantially sealed chamber having a chamber inlet and a chamber outlet;
said substantially sealed chamber being arranged to surround substantially all of said length of duct;
burner means for receiving fuel and ambient air and for producing a flow of heated combustion gas into said chamber inlet and around said length of duct, the temperature of any gas in said duct being heated to a desired level by the flow of heated combustion gas therearound;
said chamber outlet being vented to the atmosphere;
first channeling means for receiving heated gas from said duct outlet and directing said heated gas to the interior of said plenum means;
second channeling means communicating with the interior of said exhaust manifold for directing exhaust gases within said exhaust manifld to said duct inlet;
means for maintaining a flow of heated gas throughout said partially closed system.

11 more elements

Dependencies are inferred from the claim text.

Facts

Application: 05/899,385Filed 24 Apr 1978
Granted: 21 Oct 1980
Term ends: Not estimatedThe source records don’t support an estimate.

Classification4 codes

E01C 19/1027
Plant characterised by the mode of operation or the construction of the mixing apparatus; Mixing apparatus: mixing in a rotary receptacle
E01C 19/1031
Mixing in a rotary receptacle: the mixture being discharged continuously
E01C 2019/1095
Details not otherwise provided for: mixing containers having a parallel flow drum, i.e. the flow of material is parallel to the gas flow
E01C
Construction of, or surfaces for, roads, sports grounds, or the like