Heater for asphalt concrete roadways and the like

Claim 2

Equipment for heating the upper strata of asphalt concrete pavement, or the like, comprising in combination: a chamber having chamber-forming walls including a roof adapted to overlie an area of the pavement to be heated by radiant heat, said chamber-forming walls including downwardly extending peripheral side portions having lower edges thereof adapted to be closely spaced to the pavement, heater means positioned within said chamber for directing a flame toward the pavement, and radiant heating element means positioned within said chamber to be at all times between the products of combustion from said heater means and the pavement being heated, said radiant heating element means receiving the flame from said heater means, and redirecting the flame laterally and converting such flame heat to radiant heat, and exhaust manifold means in communication with said chamber at a point above said radiant heating element means to remove the products of combustion, whereby the pavement is heated to a depth greater than otherwise obtained by a direct flame from said heater means.

Claim 3

The equipment for heating the upper strata of asphalt concrete pavement according to claim 1 wherein said heating means comprises a plurality of discrete heating nozzles positioned within said chamber and directed toward the pavement, and wherein said radiant heating element means include a corresponding plurality of discrete radiant heating elements secured to the underside of each of said nozzles.

Claim 4

The equipment for heating the upper strata of asphalt concrete pavement according to claim 2 wherein said radiant heating elements are formed of a screen-like structure adapted to radiate energy of long red and infra-red wave lengths.

Claim 5

The equipment for heating the upper stratA of asphalt concrete pavement according to claim 3 wherein said radiant heating elements are formed of screen-like structures of heat-and-oxidation-resistant nickel alloy.

Claim 6

The equipment for heating the upper strata of asphalt concrete pavement according to claim 1 further including air blower supply means associated with said heating means, said air blower supply means including a variable air flow output for adjusting the turbulence of the flame produced by the heating means, whereby the pressure within said chamber is maintained substantially balanced with the atmospheric pressure externally of said chamber about the closely spaced edges of said side walls.

Claim 7

The equipment for heating the upper strata of asphalt concrete pavement according to claim 1 further including deflector means positioned between said heating means and said radiant heating element means to redirect the flame from said heating element means radially outwardly along the top surface of said radiant heating element means so that maximum heating thereof is effected and no direct flame impinges upon the pavement being heated.

Claim 8

The equipment for heating the upper strata of asphalt concrete pavement according to claim 1 further including a fuel distributing manifold positioned about said chamber wherein said heating means includes a plurality of discrete heating elements each having an orificed end thereof inserted into said fuel distribution manifold, and further including adjustable air supply means connected to said fuel distributing manifold for admixing a variable supply of air with the fuel to be burned.

Claim 9

The equipment for heating the upper strata of asphalt concrete pavement according to claim 7 further including preheating means positioned within said chamber adjacent said heating menas, said preheating means having an output end connected to said fuel distribution manifold for delivering thereto a quantity of preheated fuel to be mixed with the air supply prior to delivery to said heating means.

Claim 10

The equipment for heating the upper strata of asphalt concrete pavement according to claim 7 wherein said fuel distribution manifold is of substantially the same size and configuration as said chamber, said fuel distribution manifold being positioned above and closely spaced to said chamber.

Claim 11

Equipment for heating the upper strata of asphalt concrete pavement, or the like, comprising in combination: a heating chamber having chamber-forming walls including a roof adapted to overlie and area of the pavement to be heated by radiant heat, said chamber-forming walls including downwardly extending peripheral side portions having lower edges thereof adapted to be closely spaced to the pavement, a fuel distribution manifold positioned over said heating chamber and closely spaced thereto, said fuel distribution manifold having an air-fuel mixing chamber at the upper end thereof, a source of fuel connected to said air-fuel mixing chamber, a variable volume air supply connected to said air-fuel mixing chamber, a plurality of discrete heating nozzles positioned within said heating chamber for directing a flame toward the pavement, said heating nozzles each having a short conduit portion extending from said heating chamber into said fuel disribution manifold, and radiant heating element means positioned within said chamber to be at all times between the products of combustion from said heating nozzles and the pavement being heated, said radiant heating element means receiving the flame from said heating nozzles and redirecting the flame radially outwardly across said radiant heating element means for converting the flame heat to radiant heat, and exhaust manifold means in communication with said chamber at a point above said radiant heating element means to remove the products of combustion.

Claim 12

Equipment for heating the upper strata of asphalt concrete pavement, or the like, comprising in combination: a heating chamber having chamber-forming walls including a roof adapted to overlie and area of the pavement to be heated by radiant heat, said chamber-forming walls including downwardly extending peripheral side portions having lower edges thereof adapted to be closely spaced to the pavement, a fuel distribution manifold positioned over said heating chamber and closely spaced thereto, said fuel distribution manifold having an air-fuel mixing chamber at the upper end thereof, a source of fuel connected to said air-fuel mixing chamber, a variable volume air supply connected to said air-fuel mixing chamber, a plurality of discrete heating nozzles positioned within said heating chamber for directing a flame toward the pavement, said heating nozzles each having a short conduit portion extending from said heating chamber into said fuel disribution manifold, and radiant heating element means positioned within said chamber to be at all times between the products of combustion from said heating nozzles and the pavement being heated, said radiant heating element means receiving the flame from said heating nozzles and redirecting the flame radially outwardly across said radiant heating element means for converting the flame heat to radiant heat, and exhaust manifold means in communication with said chamber at a point above said radiant heating element means to remove the products of combustion.

Claim 13

The equipment for heating the upper strata of asphalt concrete pavement according to claim 10 wherein each of said heating nozzles includes a cylindrical body connected to the bottom of each conduit, A baffle element positioned radially inwardly within said body to create a turbulent condition of the flame as it leaves the nozzle, a plurality of radially outwardly and depending leg elements secured to said cylindrical body, and means securing said radiant heating element means to said legs.

Claim 14

The equipment for heating the upper strata of asphalt concrete pavement according to claim 11 further including flame deflection means secured to said radiant heating element means and in registry beneath said body so that the flame therefrom will impinge upon said deflector and be directed radially outwardly along said radiant heating element means.

Claim 15

The equipment for heating the upper strata of asphalt concrete pavement according to claim 10 further including fuel preheating means arranged between the fuel supply and said air-fuel mixing chamber for preheating the fuel mixture so that minimum expansion of gas occurs when the fuel mixture is burned.

Claim 16

Equipment for heating asphalt pavement or the like comprising chamber means for closely overlying an area to be heated, heater means associated with said chamber means for directing a heating flame within said chamber means and a radiant heating element mounted within the chamber means to be at all time between the products of combustion from said heater means and the pavement being heated for receiving heat from said flame and radiantly heating the pavement, and exhaust manifold means in communication with said chamber means at a point above said radiant heating element means to remove the products of combustion therethrough.

Claim 17

Equipment for heating asphalt pavement or the like comprising chamber means for closely overlying an area to be heated, heater means associated with said chamber means for directing a heating flame within said chamber means and a radiant heating element mounted within the chamber means to be at all time between the products of combustion from said heater means and the pavement being heated for receiving heat from said flame and radiantly heating the pavement, and exhaust manifold means in communication with said chamber means at a point above said radiant heating element means to remove the products of combustion therethrough.

Claim 18

In the equipment of claim 14 wherein said heating means is disposed for directing flame downwardly toward pavement and said radiant heating element, and means for deflecting the flame along said radiant heating element and for preventing direct impingement of the flame against said pavement.

Claim 19

In the equipment of claim 15 wherein said radiant heating element is a screen-like structure.

Claim 20

In the equipment of claim 16 including a plurality of said heating means and radiant heating elements, and mounting means for deflecting a flame and spaced in a predetermined pattern within said chamber means.

Claim 21

In the equipment of claim 14, further including, fuel feed manifold means having a main fuel input manifold section positioned over said chamber means and occupying an area less than said chamber means, a distribution conduit connected to said fuel input manifold section and extending across at least one dimension of said chamber means on top thereof, and a plurality of hollow arms connected to and in the fluid communication with said distribution conduit to feed air fuel mixture to said heater means assembled within said chamber means.

Claim 22

In the equipment of claim 18 wherein said heater means includes a plurality of discrete heating units each including a threaded pipe threadedly engaging a metering orifice secured to the interior of the respective associated hollow arms for receiving air fuel mixture therefrom.

Claim 23

In the equipment of claim 19 further including a coiled screen, spark arrester element positioned within said pipe to prevent backfire from said heater units into said hollow arms.

Claim 24

The equipment for heating the upper strata of asphalt concrete pavement according to claim 1, wherein said exhaust manifold means passes through said roof of said chamber.