Method and device for the calcination of finely grained to dust-form material, particularly of comminuted raw material to be used in the manufacture of cement

Claim 3

The method of heat treating a comminuted raw material for cement including the steps of claim 1: wherein the fuel supplied to the second zone has a high ignition temperature.

Claim 4

The method of heat treating a comminuted raw material for cement including the steps of claim 1: wherein at least one of the reaction zones is supplied with oxygen containing gases.

Claim 5

The method of heat treating a comminuted raw material for cement including the steps of claim 1: wherein the first reaction zone is supplied with combustion air.

Claim 6

The method of heat treating a comminuted raw material for cement including the steps of claim 4 and further including the step of: cooling the particles discharged from said sintering kiln and passing air from said cooling into said first reaction zone as combustion air.

Claim 7

A mechanism for heat treating a comminuted raw material for cement comprising in combination: a preheating means for preheating all of the raw material; means defining a first reaction zone connected to receive all of the preheated material; a first fuel supply connected to the first reaction zone for supplying a first fuel which is a solid fuel having a first heat content for supplying thernal energy for carrying out a first partial calcination reaction of all of the pre-heated material in the first reaction zone; a first separation means connected to the first reaction zone for separating the partly calcined material from the hot gases received from the first reaction zone; means defining a second reaction zone remote from said first reaction zone and connected to successively receive all of the separated material as well as any unburnt solid portion of said first fuel from the separation means; a second fuel supply connected to the second reaction zone for supplying a second fuel having a second heat content to said second reaction zone to supply thermal energy for carrying out a second calcination reaction for completing calcination of all of the partly calcined material in the second reaction zone; a second separation means connected to the second reaction zone for separating material from the hot gases; a sintering kiln remote from said first and second reaction zones and having an input connected for receiving all of the discharge of completely calcined material from said second reaction zone for sintering the completely calcined material and for producing hot exhaust gases; and means for passing hot exhaust gases from said kiln sequentially through said second reaction zone and then said first reaction zone.

Claim 8

A mechanism for heat treating a comminuted raw material for cement comprising in combination: a preheating means for preheating all of the raw material; means defining a first reaction zone connected to receive all of the preheated material; a first fuel supply connected to the first reaction zone for supplying a first fuel which is a solid fuel having a first heat content for supplying thernal energy for carrying out a first partial calcination reaction of all of the pre-heated material in the first reaction zone; a first separation means connected to the first reaction zone for separating the partly calcined material from the hot gases received from the first reaction zone; means defining a second reaction zone remote from said first reaction zone and connected to successively receive all of the separated material as well as any unburnt solid portion of said first fuel from the separation means; a second fuel supply connected to the second reaction zone for supplying a second fuel having a second heat content to said second reaction zone to supply thermal energy for carrying out a second calcination reaction for completing calcination of all of the partly calcined material in the second reaction zone; a second separation means connected to the second reaction zone for separating material from the hot gases; a sintering kiln remote from said first and second reaction zones and having an input connected for receiving all of the discharge of completely calcined material from said second reaction zone for sintering the completely calcined material and for producing hot exhaust gases; and means for passing hot exhaust gases from said kiln sequentially through said second reaction zone and then said first reaction zone.

Claim 9

A mechanism for heat treating a comminuted raw material for cement constructed in accordance with claim 6: wherein said separation means connected to the first zone directs gases to the preheating means and directs raw material to the second reaction zone.

Claim 10

A mechanism for heat treating a comminuted raw material for cement constructed in accordance with claim 6: wherein said first and said second separation means each include a cyclone separator.

Claim 11

A mechanism for heat treating a comminuted raw material for cement constructed in accordance with claim 6: including a gas conduit leading from the sintering kiln to said separation means for the second zone wherein said second reaction zone is located in said conduit.

Claim 12

A mechanism for heat treating a comminuted raw material for cement constructed in accordance with claim 6: including a cooler connected to receive clinker from said rotary kiln with a cooler air exhaust duct leading from the cooler and connected to direct cooler air to said first reaction zone.

Claim 13

A mechanism for heat treating a comminuted raw material for cement constructed in accordance with claim 6: wherein said second reaction zone is connected directly to said rotary kiln.

Claim 14

A method of heat treating a comminuted raw material for cement including the steps of claim 1: including providing a pair of parallel paths for said material with each path providing said first and second reaction zones with the paths joining in advance of the sintering kiln.

Claim 15

A mechanism for heat treating a comminuted raw material for cement constructed in accordance with claim 6: including a second structure having each of the elements of claim 9 with the separation means of said first and second structures joining in advance of the sintering kiln so that the discharge of both structures feeds to a single sintering kiln.

Claim 16

A mechanism for heat treating a comminuted raw material for cement constructed in accordance with claim 13: wherein the second reaction zones are each connected at their upstream ends to the entry of the sintering kiln.

Claim 17

A mechanism for heat treating a comminuted raw material for cement constructed in accordance with claim 6: wherein each of said reaction zones is formed within a vertically extending conduit.

Claim 18

The method of heat treating a comminuted raw material for cement including the steps of claim 1: wherein the material is calcined in said first reaction zone in the range of 90% to 95% and is calcined in the second reaction zone to at least 100%.