Production of heated bituminous mixes

Claim 3

The method of claim 1 wherein the base products are heated without direct flame contact from said burner.

Claim 4

The method of claim 1 or 2 further comprising mixing and to at least a large extent stabilizing and homogenizing the base products prior to their being fed to the treatment chamber.

Claim 5

The method of claim 1 or 2 wherein said controlling of the gaseous flow includes controlling the volume rate of exhaust of gases from the chamber.

Claim 6

The method of claim 4 comprising withdrawing a mixture of exhaust gases and external air from the chamber at a constant rate, and controlling the volume rate of exhaust of gases by controlling the proportion of external air in the mixture of exhaust gases and air.

Claim 7

The method of claim 1 or 2 comprising controlling the gaseous flow in dependence on a comparison of the measured pressure in the treatment chamber with a preset value.

Claim 8

The method of claim 1 or 2 wherein said base products include a bituminous binding agent and the method comprises feeding the base products to the treatment chamber towards the burner end thereof, and heating said base products while being tumbled to a temperature sufficient to convert the base products to a heated bituminous mix in which the binding agent is adheringly coated on the aggregate particles.

Claim 9

The method of claim 1 or 2 comprising controlling both the air supplied to the treatment chamber and the fuel supplied to the burner in dependence upon the temperature of said retrieved mix.

Claim 10

The improved method of claim 1 or 2 further comprising monitoring the pressure just axially nearer the burner than whichever of the base products feed port and heated mix retrieval port is nearer the burner.

Claim 11

A reactor for producing a heated aggregate mix comprising: a bodying defining a closed treatment chamber, which body is mounted for rotation about a predetermined longitudinal axis and arranged to permit tumbling of its contents when in such rotation; an inlet port for feeding base products including at least an aggregate mix into the treatment chamber, an outlet port for retrieving heated mix from the treatment chamber; respective inlet and outlet ports for admitting air to the treatment chamber at or adjacent one axial end thereof and exhausting gases at or adjacent the other axial end; means for inducing a flow of gases through the chamber to the gas exhaust port; a burner for heating the base products in the chamber to a temperature sufficient to convert them to a heated mix of desired specification; means for maintaining said base products feed port and said mix retrieval port substantially airtight during use of the reactor; means for supplying air to the treatment chamber via said air inlet port at a rate which depends directly upon the rate at which fuel is supplied to the burner; a sensing device within the treatment chamber for monitoring gas pressure therein in the vicinity of whichever of the base products feed port and the mix retrieval port is nearer the burner; and means for controlling said flow of gases in direct dependence upon the gas pressure monitored by said sensing device.

Claim 12

A reactor for producing a heated aggregate mix comprising: a bodying defining a closed treatment chamber, which body is mounted for rotation about a predetermined longitudinal axis and arranged to permit tumbling of its contents when in such rotation; an inlet port for feeding base products including at least an aggregate mix into the treatment chamber, an outlet port for retrieving heated mix from the treatment chamber; respective inlet and outlet ports for admitting air to the treatment chamber at or adjacent one axial end thereof and exhausting gases at or adjacent the other axial end; means for inducing a flow of gases through the chamber to the gas exhaust port; a burner for heating the base products in the chamber to a temperature sufficient to convert them to a heated mix of desired specification; means for maintaining said base products feed port and said mix retrieval port substantially airtight during use of the reactor; means for supplying air to the treatment chamber via said air inlet port at a rate which depends directly upon the rate at which fuel is supplied to the burner; a sensing device within the treatment chamber for monitoring gas pressure therein in the vicinity of whichever of the base products feed port and the mix retrieval port is nearer the burner; and means for controlling said flow of gases in direct dependence upon the gas pressure monitored by said sensing device.

Claim 13

The reactor of claim 10 wherein the flow control means includes valving positioned to control the volume rate of flow through the gas outlet port.

Claim 14

The reactor of claim 11 wherein a constant evacuation rate exhaust fan is mounted in an exhaust duct communicating the gas outlet port and wherein said valving comprises an adjustable bleed from atmosphere interposed in the exhaust duct between the gas outlet port and the fan.

Claim 15

The reactor of claim 10 wherein said flow control means includes comparison means to compare the pressure monitored by said sensing device with a preset value and to pass a control signal dependent upon said comparison to a device for adjusting gas flow through the gas outlet port.

Claim 16

The reactor of claim 10 wherein a second sensing device is positioned at or adjacent said heated mix retrieval port for monitoring the temperature of the retrieved mix, said burner being coupled to said second sensing device for controlling said fuel supply to the burner in dependence upon the monitored temperature.

Claim 17

The reactor of claim 10 further including means to mix and to at least a large extent stabilize and homogenize the base products prior to their being fed to the treatment chamber.

Claim 18

The reactor of claim 10 wherein the sensing device is disposed just axially nearer the burner than whichever of the base products feed port and mix retrieval port is nearer the burner.