| 摘要 |
PURPOSE:To reduce thermal load on a baking furnace by raising the decaroxylation rate of raw materials by supplying powdery raw materials for cement into the baking furnace through a preheater combined with a calciniing furnace with an independent heat source. CONSTITUTION:Powdery raw materials for cement, charged 1 in a raw material preheater NSP, is preheated to about 750 deg.C by a high-temperature waste gas discharged 2F upwards from a calcining furnace 4 and then charged into the furnace 4, where a fuel is injected and at the same time part of cooling air heated, coming from a clinker cooler 9, is supplied in such a way as to promote the decarboxylation reaction of the powdery raw materials. And, the calcined raw materials, after the decarboxylation reaction has been almost completely finished, are introduced into a baking furnace 6, where a fluidized bed is formed by a high-temperature air from the clinker cooler 9. And, the calcined raw matirials are granulated and baked in the furnace 6 kept at 1,400-1,500 deg.C. Then, clinker of comparatively coarse grain size, formed in the furnace 6, is sent to the cooler 9 and clinker and unbaked raw materials of fine grain size are sent in a fluidized state to a high-temperature separator 8. Solid substances separated and collected in the separator 8 are charged into the furnace 6 and unbaked raw materials are baked here. |
