How to select gypsum calcination equipment according to calcination method

Gypsum calcination equipment depends on the type and properties of gypsum: natural gypsum or industrial by-product gypsum; It is granular or powdery. If it is powdery, rapid calcination equipment can also be selected. If it is granular, it is better to select equipment that stays in the kiln for a long time.

Type of terminal products: if gypsum building materials products are produced, such as various gypsum boards, gun blocks, etc., rapid calcining equipment should be selected. Because the building gypsum produced by the rapid method is fast in setting and hardening, it can improve the production efficiency and accelerate the turnover of molds; If gypsum cementitious materials are produced, such as plastering gypsum, gypsum binder, gypsum joint materials, etc., slow calcination equipment should be selected. Because the products calcined at a slow speed are slow in setting and hardening, which is conducive to reducing the amount of admixture and reducing production costs; If both types of products are produced, the products calcined slowly shall be selected.

The frying pan calcination belongs to the low temperature slow calcination mode. The calcined gypsum from continuous frying pan is a mature technology at home and abroad, with stable production, easy operation and guaranteed product quality balance. It is suitable for calcining powdered gypsum. If it is used for industrial by-product gypsum, a set of air flow drying device shall be added to remove more than 10% of free water. The frying pan can use solid, liquid and gas fuels.

Fluidized bed furnace: a vertical straight cylindrical vessel, with a gas distribution plate installed at the bottom, allows the air flow to enter the bed evenly from the bottom during operation. A large number of heating tubes are installed in the bed. The medium in the tubes is saturated steam or heat transfer oil. After gypsum particles enter the furnace, they become fluidized when heated. At the same time, the heat is transferred to the fluidized gypsum powder outside the tube through the tube wall, so that it can be boiled, dehydrated and decomposed.

Airflow calcination means that the hot gas directly contacts with the powder, and the dihydrate gypsum is rapidly dehydrated to form hemihydrate gypsum. This method has the advantages of reasonable heat utilization, compact equipment, simple use and high efficiency, and is suitable for natural gypsum and gypsum calcination equipment.

Direct heating rotary kiln: the thermal medium directly contacts with gypsum material to dehydrate it into hemihydrate gypsum or anhydrite. Gypsum rotates forward in the small angle inclined cylinder, and the thermal medium moves in the same direction or opposite direction with it. During the movement, gypsum dehydration is completed, and continuous feeding and discharging are continuous operations. Since the thermal efficiency of direct firing is higher than that of external firing rotary kiln, gas, oil and coal can be used as fuel.