Production scheme of construction gypsum with use of rotating furnaces
Samara plant "Strommashina" performs the design, production, supply and installation supervision of construction gypsum production line. Phone references: (846) 244-43-83
Production scheme of construction gypsum in rotating furnaces (drying cylinders) is provided in fig.1
Depending on a lump size of initial gypsum rock and the required lump size headed to firing, crushing is effected according to one-or two-level scheme in jaw or other types of crushers. Raw material is crushed up to the particle sizes 0…20-35 mm in cross section.
Gypsum broken stone received if necessary undergoes screening into fractions 0…10, 10…20 and 20…35 mm that are headed into the relevant hoppers above the firing kiln. Usually broken stone of various fractions is fired separately. For each fraction the relevant mode of firing is being chosen. Gypsum broken stone from hopper by means of a feeder for example a disk-shaped, continuously enters the rotating furnace.
Firing of gypsum in rotating furnaces can be effected at immediate contact with hot gases forming at fuel consumption or by means of heat transfer through drum walls at its outer heating.
Rotating furnaces (drying cylinders) can operate at solid, liquid and gas fuel. For each variant Samara plant «Strommashina» selects separate processing equipment and a firing technology.
Furnace inlet gas temperature (drying cylinder) at direct current – 950…1000oС, at counter current – 750…800oС. Furnace outlet gas temperature at direct current – 170…220oС, at counter current – 100…110oС.
Fired material enters the supply bunkers located above the ball mill. Uniform mill feeding with material is provided by feeder. Material supplied to the mill has temperature 800…1000oС.
In a ball mill 1456А (usually two-chambers) the grinding of fired gypsum stone is performed. As opposed to kettles the fired product in furnaces turns out nonhomogenous on modification composition; there is a significant quantity of underfiring (two-hydrate calcium sulfate) and overfiring (anhydrite). In a ball mill except of grinding the aligning of product material constitution occurs by means of transition of underfiring and overfiring into semihydrate.
After grinding the gypsum binding is headed to storage bins (silo) and for packaging.
Modern gypsum binding productions are effected under similar processing schemes, however preferably for transportation of granular and dust materials the pneumatic conveying systems are sued providing the high level of air cleaning from dust.