The disclosure discloses a method for preparing calcium oxide using multistage suspension preheater kiln. The steps of the method are: (1) the limestone powder is fed to the multistage suspension preheater kiln for preheating to 800 C. to 900 C.; (2) A preheated material is fed to a decomposition furnace, and calcined at 900 C. to 1100 C. for 25 s to 35 s; (3) A calcined material is fed to a rotary kiln, and calcined at 1100 C. to 1300 C. for 25 to 35 minutes, and finally cooled to obtain calcium oxide.

The disclosure discloses a method for preparing calcium oxide using multistage suspension preheater kiln. The steps of the method are: (1) the limestone powder is fed to the multistage suspension preheater kiln for preheating to 800 C. to 900 C.; (2) A preheated material is fed to a decomposition furnace, and calcined at 900 C. to 1100 C. for 25 s to 35 s; (3) A calcined material is fed to a rotary kiln, and calcined at 1100 C. to 1300 C. for 25 to 35 minutes, and finally cooled to obtain calcium oxide.

An apparatus for producing lightweight aggregates is provided that includes an elongate furnace vessel with a delivery end for receiving particulate matter feedstock to be processed and a downstream particulate matter discharge end for discharging processed particulate matter as lightweight aggregates. A perforated distributor plate is positioned in the vessel. A fluidized bed zone is defined above the plate that has an upstream heating section for converting the particulate matter into processed particulate matter due to exposure of pressurized combustion gases and a downstream cooling section for cooling the processed particulate matter. Below the plate is a heating compartment for delivering the combustion gases through the plate into the heating section and a cooling compartment for delivering cooling air through the plate into the cooling section to cool the particulate matter processed in the upstream heating section. A downstream airflow-inducing apparatus is provided for inducing a flow of the feedstock entrained in the airflow downstream from the heating section into the cooling section of the vessel. A discharge apparatus is provided for discharging the processed particulate matter from the vessel in a suspended condition in a fluidizing air stream.

Plants for regenerating foundry sand are provided having a combustion chamber, which has at least one inlet for introducing sand to be regenerated into the combustion chamber, nozzles for feeding combustible gas into the combustion chamber, nozzles for injecting air so as to maintain a heated fluidized bed of sand in the combustion chamber, a cooling chamber for cooling sand coming from the combustion chamber, the cooling chamber having nozzles for blowing air in order to maintain a fluidized bed of sand in the cooling chamber, refrigerating pipes arranged above the air nozzles, a communicating duct which connects the combustion chamber with the cooling chamber, the communicating duct including a vertical or inclined lower end portion which is at least partially surrounded by or adjacent to a plurality of the refrigerating pipes in the cooling chamber, and wherein the lower end portion has a bottom outlet arranged at a lower level with respect to at least one of the refrigerating pipes.

Plants for regenerating foundry sand are provided having a combustion chamber, which has at least one inlet for introducing sand to be regenerated into the combustion chamber, nozzles for feeding combustible gas into the combustion chamber, nozzles for injecting air so as to maintain a heated fluidized bed of sand in the combustion chamber, a cooling chamber for cooling sand coming from the combustion chamber, the cooling chamber having nozzles for blowing air in order to maintain a fluidized bed of sand in the cooling chamber, refrigerating pipes arranged above the air nozzles, a communicating duct which connects the combustion chamber with the cooling chamber, the communicating duct including a vertical or inclined lower end portion which is at least partially surrounded by or adjacent to a plurality of the refrigerating pipes in the cooling chamber, and wherein the lower end portion has a bottom outlet arranged at a lower level with respect to at least one of the refrigerating pipes.

A counter-current catalyst regenerator with at least two stages of counter-current contact along with a regenerator riser is proposed. Each stage may comprise a permeable barrier that allows upward passage of oxygen-containing gas and downward passage of coked catalyst into each stage, but inhibits upward movement of catalyst to mitigate back mixing and approximate true counter-current contact and efficient combustion of coke from catalyst. The regenerator riser may provide a passage to transport the catalyst and may serve as a secondary stage for coke combustion to provide the regenerated catalyst.

A counter-current catalyst regenerator with at least two stages of counter-current contact along with a regenerator riser is proposed. Each stage may comprise a permeable barrier that allows upward passage of oxygen-containing gas and downward passage of coked catalyst into each stage, but inhibits upward movement of catalyst to mitigate back mixing and approximate true counter-current contact and efficient combustion of coke from catalyst. The regenerator riser may provide a passage to transport the catalyst and may serve as a secondary stage for coke combustion to provide the regenerated catalyst.

A device and a method for producing high-purity nano molybdenum trioxide are provided. The device comprises a raw material bin (1), a feeding machine (2), a subliming furnace (7), a first vent tube (24), a second vent tube (25), a spraying device (23) and a filtering assembly. The sublimated molybdenum trioxide is cooled with clean and dehumidified air so as to finally obtain the nano molybdenum trioxide, and the recycling mode is reliable, pollution-free and high in efficiency.

A device and a method for producing high-purity nano molybdenum trioxide are provided. The device comprises a raw material bin (1), a feeding machine (2), a subliming furnace (7), a first vent tube (24), a second vent tube (25), a spraying device (23) and a filtering assembly. The sublimated molybdenum trioxide is cooled with clean and dehumidified air so as to finally obtain the nano molybdenum trioxide, and the recycling mode is reliable, pollution-free and high in efficiency.

A counter-current catalyst regenerator with at least two stages of counter-current contact along with a regenerator riser is proposed. Each stage may comprise a permeable barrier that allows upward passage of oxygen-containing gas and downward passage of coked catalyst into each stage, but inhibits upward movement of catalyst to mitigate back mixing and approximate true counter-current contact and efficient combustion of coke from catalyst. The regenerator riser may provide a passage to transport the catalyst and may serve as a secondary stage for coke combustion to provide the regenerated catalyst.