Heat processing of minerals

Claim 2

In heat processing apparatus of the type employing a rotary kiln, material preburning and drying sections adjacent the inlet end of the kiln, a cooling zone adjacent the outlet end of the kiln, means for advancing the material through the apparatus, and gas flow means to draw exhaust gases from the kiln through the bed of material in the preburning section and for introducing said gases through a portion of the bed in the drying section; the improvement comprising means dividing said drying section into plural chambers through which the material is advanced, with said gas flow means transmitting the kiln exhaust gases from the preburning section to one of said chambers, gas conveying means connecting said cooling zone to a second of said chambers of said drying section, and means for causing hot gases of a desired temperature and volume from said cooling zone to flow through the gas conveying means for conditioning of the material in said second chamber.

Claim 3

The apparatus of claim 1, wherEin the material is advanced through said one chamber of the drying section before passing through the other chamber in which the flow of hot gases from the cooling zone is encountered.

Claim 4

The apparatus of claim 1, wherein said hot gases are drawn from the material receiving end portion of the cooling zone.

Claim 5

The apparatus of claim 3, wherein the material is advanced through said one chamber of the drying section and then through such other chamber thereof.

Claim 6

The apparatus of claim 1, wherein said exhaust gases and said hot gases are caused to flow respectively through the material in the chambers of the drying section in opposite vertical directions.

Claim 7

The apparatus of claim 1 wherein the gas conveying means comprises a fan, first conduit means connecting the inlet of said fan to the cooling zone, and second conduit means connecting the outlet of said fan to the said chamber of the drying section.

Claim 8

In heat processing apparatus of the type employing a rotary kiln, material preburning and drying sections, said sections being arranged in series to provide a material flow stream from said drying section to the preburning section and then into the rotary kiln, a cooling zone adjacent to the outlet end of the kiln, means for advancing the material through the apparatus, gas flow means comprising first conduit means to draw exhaust gases from the kiln through the bed of material in the preburning section and for introducing said gases through a portion of the bed in the drying section, a bypass conduit connecting a second portion of said preburning section to said first conduit means at a location between the preburning section and the inlet to the preburning section; the improvement comprising means for dividing said drying section into plural chambers through which the material is advanced, with said gas flow means transmitting the kiln exhaust gases from the preburning section to one of said chambers, gas conveying means connecting said cooling zone to a second of said chambers of said preconditioning section, said gas conveying means comprising: a fan; first conduit means connecting the inlet of said fan to said cooling zone; second conduit means connecting the outlet of said fan to said chamber of said second drying chamber; and damper means in said first conduit for controlling temperature and heat input of air entering said first conduit.

Claim 9

In heat processing apparatus of the type employing a rotary kiln, material preburning and drying sections, said sections being arranged in series to provide a material flow stream from said drying section to the preburning section and then into the rotary kiln, a cooling zone adjacent to the outlet end of the kiln, means for advancing the material through the apparatus, gas flow means comprising first conduit means to draw exhaust gases from the kiln through the bed of material in the preburning section and for introducing said gases through a portion of the bed in the drying section, a bypass conduit connecting a second portion of said preburning section to said first conduit means at a location between the preburning section and the inlet to the preburning section; the improvement comprising means for dividing said drying section into plural chambers through which the material is advanced, with said gas flow means transmitting the kiln exhaust gases from the preburning section to one of said chambers, gas conveying means connecting said cooling zone to a second of said chambers of said preconditioning section, said gas conveying means comprising: a fan; first conduit means connecting the inlet of said fan to said cooling zone; second conduit means connecting the outlet of said fan to said chamber of said second drying chamber; and damper means in said first conduit for controlling temperature and heat input of air entering said first conduit.