A method for coating fibres includes coating short fibres having an average length less than or equal to 5 mm by chemical vapour deposition in a fluidised bed, the short fibres treated being made of ceramic material or carbon and being mixed with spacer particles distinct from the short fibres, the spacer particles having an average diameter greater than or equal to 20 μm.

The present invention relates to a gas distribution unit for a fluidized bed reactor system, a fluidized bed reactor system having the gas distribution unit, and a method for preparing granular polysilicon using the fluidized bed reactor system. The gas distribution unit for a fluidized bed reactor system according to the present invention enables gas flow rate control and gas composition control for each zone within the plenum chamber. In addition, a fluidized bed reactor system having the gas distribution unit enables shape control of a fluidized bed (in particular, transition between a bubbling fluidized bed and a spout fluidized bed). The method for preparing granular polysilicon using the fluidized bed reactor system not only simultaneously improves process stability and productivity, but also enables more flexible handling in the event of an abnormal situation.

A method and a sensor device for evaluating residual Sulphur in a cement preheater of a cement kiln, wherein the residual Sulphur is based on the values of the fuel Sulphur content, the fuel rate of consumption, the hotmeal quality and the clinker Sulphur content. A method for evaluating blockage in a cement preheater includes evaluating the residual Sulphur in the cement preheater, determining an agglomeration rate of Sulphur compounds agglomerating on an inner surface of the cement preheater based on the residual Sulphur, and evaluating a level of blockage in at least one predetermined pathway of the cement preheater using a blockage evaluation unit, wherein the level of blockage is based on the agglomeration rate.

A method and a sensor device for evaluating residual Sulphur in a cement preheater of a cement kiln, wherein the residual Sulphur is based on the values of the fuel Sulphur content, the fuel rate of consumption, the hotmeal quality and the clinker Sulphur content. A method for evaluating blockage in a cement preheater includes evaluating the residual Sulphur in the cement preheater, determining an agglomeration rate of Sulphur compounds agglomerating on an inner surface of the cement preheater based on the residual Sulphur, and evaluating a level of blockage in at least one predetermined pathway of the cement preheater using a blockage evaluation unit, wherein the level of blockage is based on the agglomeration rate.

A fluidized bed system includes a first nozzle group that is provided inside a fluidized bed furnace, a second nozzle group that is provided inside the fluidized bed furnace, a first supply section that supplies a gas into the fluidized bed furnace through the first nozzle group, a second supply section that supplies the gas into the fluidized bed furnace through both the first and second nozzle groups, and a control section that controls the second supply section during a start-up operation to supply the gas into the fluidized bed furnace to form a fluidized bed of a fluid medium inside the fluidized bed furnace, and stops the supply of the gas by the second supply section and controls the first supply section during a normal operation to supply the gas into the fluidized bed furnace to form the fluidized bed of the fluid medium inside the fluidized bed furnace.

A fluidized bed system includes a first nozzle group that is provided inside a fluidized bed furnace, a second nozzle group that is provided inside the fluidized bed furnace, a first supply section that supplies a gas into the fluidized bed furnace through the first nozzle group, a second supply section that supplies the gas into the fluidized bed furnace through both the first and second nozzle groups, and a control section that controls the second supply section during a start-up operation to supply the gas into the fluidized bed furnace to form a fluidized bed of a fluid medium inside the fluidized bed furnace, and stops the supply of the gas by the second supply section and controls the first supply section during a normal operation to supply the gas into the fluidized bed furnace to form the fluidized bed of the fluid medium inside the fluidized bed furnace.

The present invention relates to a gas distribution unit for a fluidized bed reactor system, a fluidized bed reactor system having the gas distribution unit, and a method for preparing granular polysilicon using the fluidized bed reactor system. The gas distribution unit for a fluidized bed reactor system according to the present invention enables gas flow rate control and gas composition control for each zone within the plenum chamber. In addition, a fluidized bed reactor system having the gas distribution unit enables shape control of a fluidized bed (in particular, transition between a bubbling fluidized bed and a spout fluidized bed). The method for preparing granular polysilicon using the fluidized bed reactor system not only simultaneously improves process stability and productivity, but also enables more flexible handling in the event of an abnormal situation.

Embodiments of a system and a method for manufacturing calcined gypsum can include a calcination unit having a heating unit with at least one variable heater and a calciner temperature control device having a temperature sensor and a controller in operable arrangement with the temperature sensor and the heating unit. The calciner temperature control device is configured to adjust a thermal energy output rate of the heating unit based upon a comparison of the detected temperature and a target set point temperature so as to allow the supply of gypsum to be fed into the calcining chamber at a constant rate.