Flow Chart of the Gypsum Powder Production Line:
Jaw Crusher → Hammer Crusher → Lifter → Material Silo → Measuring Pump → Mill → Selecting Power Machine → Lifter → Raw Material Silo → Screw Feeder → Calciner(Fluidized Bed Furnace) → Electrostatic Cleaning → Cooling → Lifter → Finished Material Silo
1. Break the Raw Material System
The crusher(Jaw Crusher, Hammer Crusher) breaks the big sized gypum ore/stone into small ones with 25mm in diameter.
The diameter of gypsum lump should less than 300mm, we use bucket lift truck or manpower transport gypsum lump into jaw crusher, stone crusher gypsum plaster stone, so that less than50mm, the bucket elevator and screw conveyor into the grinder bin.
2. Mill System
After Storing and conveying, the storing and conveying, the crushed parts are taken into the mill for grinding.
Grinding Powder Process.
The gypsum materials from crushing process, they will be conveying into mill silo pass through bucket elevator and screw conveyor. These gypsum materials will be evenly feed into mill via vibrating feeder, the small size gypsum materials will become to gypsum powder due to the grinding effect, gypsum powder will go out of mill with wind, and will be chosen by powder separator which is on the top of mill, the qualified fineness of powder are separated from the top of mill, other unqualified powder will return into mill for grind again. The qualified powder through cyclone dust collector and bag-type splitter will gather into screw convey, and then bucket elevator & screw conveyor transport gypsum powder to calcination process, the surplus powder will be storage into raw material silo through screw conveyor.
3. Calcining System ( the key point for the drying and dehydration process)
The powder concentrator carries the gysum powders which match to the needed fineness to the calciner for calcining. And the unqualified powder are back to the mill until it is qualified.
Composition: The body of the Calciner, Roots Blower, High Voltahe Electrostatic Precipitator, Transformer
Working Principle of the Drying System: The calciner mainly consists of intensice thermal coils which are narraw in diameter. The hot oil are put into the thermal coils. After the exchangeing of the heat, the heat energy are released to the calciner. On the bottom, there is a root blower. The cool wind blows into the calciner by optimum of the distributor in order to mae the powders become ebullient. In certain degree, the quality of the powders which are dehydrated the crystal water is becoming light. Then they will flow to the exit. So the quality of the gypsum powders is stable.
Moreover, this equipment equiped with dry electrostatic precipitator to dust. The rate of the dusting can reach to at least 95%, which eliminate the dust pollution very well.
The powder materials which are from grinding powder process or powder silo, they will through vertical, horizontal conveyor and then through measuring screw conveyor into boiling furnace for calcination. Boiling furnace take high temperature heat transfer oil as heat source, high temperature heat transfer oil is provided by coal-fired thermal oil boiler. When the high temperature transfer oil enter boiling furnace, its heat will transmit to gypsum powder by heat exchanger, and make CaSO4 *2H2O become into CaSO4 *1/2H2O (building gypsum). During calcination, we adjust discharge temperature according to raw gypsum’s feeding quantity, calcined building gypsum continuous automatic discharge from boiling furnace, and are conveyed to building gypsum silo pass through screw conveyor and bucket elevator. And the heat transfer oil will return flow into coal-fired thermal oil boiler for reheat.
4. End Product Transportation and Storagy
After calcining, the qualified gypsum powder(usually called plaster of paris) are sent to clinker container for storing, or are sent to the manufacturing workshops for use.
The time of production: 300 days/year×24 hours
The initial setting time: 3~8min adjustable;
The final setting time: 6~15min adjustable