Apparatus for calcining powdered cement material

Claim 2

Apparatus for calcining powdered cement material comprising: a kiln having an entrance; a suspension preheater including a plurality of cyclones arranged in vertical juxtaposition with at least a lowermost and a second lowermost cyclone being provided, said cyclones operating to separate cement material from gases when a mixture thereof is introduced therein, said lowermost cyclone having an upper inlet and a lower outlet connected to said kiln to introduce separated cement material thereinto; a gas duct connected at one end to the entrance of said kiln and at its opposite end to said upper inlet of said lowermost cyclone; a gas producer located beneath said second lowermost cyclone and having a bottom opening into said gas duct at a point below where said opposite end of said gas duct is connected to said upper inlet of said lowermost cyclone; means for supplying cement material from said second lowermost cyclone to said gas producer; means for supplying fuel and primary air to said gas producer; and secondary air supplying means located adjacent the point where said bottom of said gas producer opens into said gas duct.

Claim 3

Apparatus according to claim 1 wherein said secondary air supplying means is located above the point where said bottom of said gas producer opens into said gas duct.

Claim 4

Apparatus according to claim 1, further including means for supplying preheated cement material directly from said second lowermost cyclone into said gas duct.

Claim 5

In apparatus for heating powdered cement material, a gas producer comprising: a casing having a surrounding wall, a bottom center portion and a top, with a chamber including a chamber bottom being defined by said surrounding wall within said casing; a plurality of air injection nozzles for blowing primary air from said surrounding wall in said chamber defined therein so as to form a swirling air stream over and along said chamber bottom; a material chute for supplying powdered material into said swirling stream of air being issued from said air injection nozzles; an exhaust duct connected to said bottom center of said casing to draw in said powdered material downwardly in said swirling stream; and a burner for blowing fuel from the top of said casing downwardly toward said exhaust duct, with produced gas being conducted outwardly of said casing together with powdered material through said exhaust duct for further combustion with secondary air.

Claim 6

In apparatus for heating powdered cement material, a gas producer comprising: a casing having a surrounding wall, a bottom center portion and a top, with a chamber including a chamber bottom being defined by said surrounding wall within said casing; a plurality of air injection nozzles for blowing primary air from said surrounding wall in said chamber defined therein so as to form a swirling air stream over and along said chamber bottom; a material chute for supplying powdered material into said swirling stream of air being issued from said air injection nozzles; an exhaust duct connected to said bottom center of said casing to draw in said powdered material downwardly in said swirling stream; and a burner for blowing fuel from the top of said casing downwardly toward said exhaust duct, with produced gas being conducted outwardly of said casing together with powdered material through said exhaust duct for further combustion with secondary air.

Claim 7

In apparatus for heating powdered cement material, at least one gas producer comprising: a material dispersion chamber having a surrounding wall with a bottom center portion defined therein, and equipped with a plurality of air injection nozzles for blowing primary air into said chamber through said surrounding wall to form therein a swirling air stream; a material chute for supplying powdered material into said swirling stream of air being issued from said air injection nozzles; a swirl-mixing chamber defined in said gas producer below said dispersion chamber with a contour tapering downwardly away from said dispersion chamber to gradually enlarge said swirl-mixing chamber in said downward direction; said gas producer being structured with said dispersion chamber integrally communicated at said bottom center with said swirl-mixing chamber; and a burner located in the highest stage of said dispersion chamber for blowing fuel from the top of said chamber downwardly toward said swirl-mixing chamber; with produced gas being conducted downwardly and outwardly together with powdered material from the lowest stage of said swirl-mixing chamber for further combustion with secondary air.

Claim 8

In apparatus for heating powdered cement material, at least one gas producer comprising: a material dispersion chamber having a surrounding wall with a bottom center portion defined therein, and equipped with a plurality of air injection nozzles for blowing primary air into said chamber through said surrounding wall to form therein a swirling air stream; a material chute for supplying powdered material into said swirling stream of air being issued from said air injection nozzles; a swirl-mixing chamber defined in said gas producer below said dispersion chamber with a contour tapering downwardly away from said dispersion chamber to gradually enlarge said swirl-mixing chamber in said downward direction; said gas producer being structured with said dispersion chamber integrally communicated at said bottom center with said swirl-mixing chamber; and a burner located in the highest stage of said dispersion chamber for blowing fuel from the top of said chamber downwardly toward said swirl-mixing chamber; with produced gas being conducted downwardly and outwardly together with powdered material from the lowest stage of said swirl-mixing chamber for further combustion with secondary air.

Claim 9

Apparatus according to claim 5, wherein said burner for blowing fuel from the top of said dispersion chamber constitutes a main burner, said apparatus further comprising auxiliary burner means for supplying part of the fuel from the surrounding wall of said chamber to the mixture of oxygen-containing gases and cement material swirling together in the chamber.

Claim 10

Apparatus according to claim 5, wherein said material dispersion chamber is formed with a weir along its bottom center opening at which said swirl-mixing chamber opens.

Claim 11

Apparatus according to claim 5, wherein two material dispersion chambers are provided in two stages, one above the other.