System for handling high sulfur materials

In a material heat-treating furnace apparatus (9) having structure defining a drying chamber (21) for receiving a cement material to be treated and for preconditioning the material, and at least one preheat chamber (23-24) for receiving material from the drying chamber (21), a travelling grate (14) mounted within the structure for conveying the material successively through the respective chambers, a first windbox (30) located beneath the travelling grate (14) in the drying chamber (21), a second windbox (62) located beneath the travelling grate in the preheat chamber (23-24), a kiln (28) mounted to receive material directly from the preheat chamber (23-24), and at least one cooling chamber (43) disposed to receive material from the kiln, the drying and preheat chambers, the kiln, and the cooling chamber being connected in a series flow arrangement to define a material flow path from the drying chamber to the cooling chamber, a fan system means (74) including a first dust collector means (73) for withdrawing gases from the second windbox (62) and passing them to the drying chamber (21), and gas-conveying means for directing usable gases developed within the apparatus into various zones of the apparatus, comprising:

• means (81-91-93-98-99) for directing off-gases from the kiln (28) into the preheat chamber (23-24);
• a supply source (63) of lime-bearing material which is chemically reactive with sulfur;
• a first duct (67) means connected between said supply source of a lime-bearing material which is chemically reactive with sulfur and the preheat chamber (23-24);
• a mixing device (81) connected to the preheat chamber (23-24) for receiving kiln off-gases which have been treated with the lime-bearing material;
• an air supply (82) connected to said mixing device (81) for mixing air with the treated kiln off-gases to temper said kiln off-gases;
• a second duct means (109) connected to said mixing device (81);
• a second dust collector means (90-91) connected to said mixing device (81) and to the preheat chamber (23-24) for the removal of solid sulfur compound dust particles from the tempered mixed gases prior to said tempered mixed gases being supplied to the preheat chamber;
• and,
• a third duct means (93-99) connected between said second dust collector means (90-91) and the preheat chamber for passing cleansed tempered mixed gases back through the material in the preheat chamber.