Introduction
The main composition of gypsum is hydrate gypsum(CaSO4.2H2O). however, the gypsum powder used in practical production(such as the gypsum powder for gypsum board, for mould, for plastering)is to dry and dewater the dehydrate gypsum which of certain fineness, reduce the content of crystallization water in it, so the standard of crystallization of gypsum powder can qualify all kinds of gypsum powder, because it can change into plaster of pairs. Plaster of pairs can re-integrated with water when it is applied into production, and it can be processed into new type building materials with a high intensity, such as gypsum board, gypsum block, etc.
Existing gypsum powder drying technologies are frying boiler and rotary kiln plant. It means that put the gypsum powder into the frying boiler and coil pipe, and before the gypsum powder was put, the heat produced by the burning of the medium in kiln furnace was send into the frying boiler and rotary kiln plant by fan. In this way, the quality of gypsum powder is difficult to guarantee, because the content of crystallization water is uneven.
2.The working principle of ebullience calciner
The main working principle of the ebullience calciner drying system: the main part of the ebullience calciner is formed by the small-diameter cooling coil pipes. The heat transfer oil is piped into coil pipe and releases heat into the internal of furnace after exchanging heat. Roots blower which can blow the cold wind into the furnace by air distribution plate is equipped at the bottom part of the ebullience calciner, by blowing let the powder in furnace boiling. And under certain temperature, the powder which has been dried and without crystallization water becomes light, so it can flow to the outlet automatically. The quality of the gypsum powder produced in this way is stable and the content of crystallization water is large, so it is easy to control the time of solidification. In addition, the dry electrostatic precipitator was equipped to this machine; the efficiency of dust removal can reach more than 95% after the dust removal, eliminating the dust pollution.