Provided are: a useful bed medium for a fluidized bed with good fluidity, the bed medium being usable in a fluidized bed furnace using biomass material and coal material as fuel; and a useful bed medium for a fluidized bed with good durability, the bed medium not easily forming an agglomerate of its particles, and being resistant to collapsing. The bed medium for a fluidized bed in a fluidized bed furnace for combusting or gasifying the fuel is formed of artificially-produced spherical refractory particles containing not less than 40% by weight of Al2O3 and not more than 60% by weight of SiO2 and having an apparent porosity of not more than 5%, and a ratio by weight of agglomerated particles in the bed medium is not more than 20% after three heat treatment tests on the bed medium at 900° C. for 2 hours under coexistence with the fuel.

Provided are: a useful bed medium for a fluidized bed with good fluidity, the bed medium being usable in a fluidized bed furnace using biomass material and coal material as fuel; and a useful bed medium for a fluidized bed with good durability, the bed medium not easily forming an agglomerate of its particles, and being resistant to collapsing. The bed medium for a fluidized bed in a fluidized bed furnace for combusting or gasifying the fuel is formed of artificially-produced spherical refractory particles containing not less than 40% by weight of Al2O3 and not more than 60% by weight of SiO2 and having an apparent porosity of not more than 5%, and a ratio by weight of agglomerated particles in the bed medium is not more than 20% after three heat treatment tests on the bed medium at 900° C. for 2 hours under coexistence with the fuel.

A method of heat transfer wherein a flat metal product having a broad face and a temperature upper to 400° C. is put in contact with a fluidized bed of solid particles, the solid particles having a direction of circulation (D), wherein the flat metal product is put in contact with the solid particles so that its broad face is parallel to the direction (D) of circulation of the solid particles and wherein a gas is injected so that the solid particles be in a bubbling regime, the solid particles capturing the heat released by the metal product and transferring the captured heat to a transfer medium. An associated device is also provided.

Provided are: a useful bed medium for a fluidized bed with good fluidity, the bed medium being usable in a fluidized bed furnace using biomass material and coal material as fuel; and a useful bed medium for a fluidized bed with good durability, the bed medium not easily forming an agglomerate of its particles, and being resistant to collapsing. The bed medium for a fluidized bed in a fluidized bed furnace for combusting or gasifying the fuel is formed of artificially-produced spherical refractory particles containing not less than 40% by weight of Al2O3 and not more than 60% by weight of SiO2 and having an apparent porosity of not more than 5%, and a ratio by weight of agglomerated particles in the bed medium is not more than 20% after three heat treatment tests on the bed medium at 900 C. for 2 hours under coexistence with the fuel.

Provided are: a useful bed medium for a fluidized bed with good fluidity, the bed medium being usable in a fluidized bed furnace using biomass material and coal material as fuel; and a useful bed medium for a fluidized bed with good durability, the bed medium not easily forming an agglomerate of its particles, and being resistant to collapsing. The bed medium for a fluidized bed in a fluidized bed furnace for combusting or gasifying the fuel is formed of artificially-produced spherical refractory particles containing not less than 40% by weight of Al2O3 and not more than 60% by weight of SiO2 and having an apparent porosity of not more than 5%, and a ratio by weight of agglomerated particles in the bed medium is not more than 20% after three heat treatment tests on the bed medium at 900 C. for 2 hours under coexistence with the fuel.

A thermally treated metal sheet or article as well as processes and systems for making the thermally treated sheet or article is provided. The process comprises heating and/or cooling the metal sheet by non contact thermal conduction for sufficiently long to provide a desired microstructure and mechanical properties. The process results in thermally treated metal sheets.

A thermally treated metal sheet or article as well as processes and systems for making the thermally treated sheet or article is provided. The process comprises heating and/or cooling the metal sheet by non contact thermal conduction for sufficiently long to provide a desired microstructure and mechanical properties. The process results in thermally treated metal sheets.

A method for heating a semi-finished steel product, including a pre-heating step, performed in a pre-heating device including a chamber containing solid particles, a heat exchanger, a support able to support the semi-finished steel product, a gas injector, and a heating step, performed in a furnace, wherein, the pre-heating step includes the steps of i. injecting a gas into the first chamber so as to form a first fluidized bed, ii. heating the fluidized bed by the heat exchanger, iii. putting the semi-finished steel product, into the fluidized bed and onto the support such the fluidized bed is able to transfer heat to the semi-finished steel product, iv. taking out the semi-finished steel product when its temperature is from 200 C. to 1000 C., and the heating step includes the step heating the semi-finished product to a temperature from 1100 to 1400 C.

A method for heating a semi-finished steel product, including a pre-heating step, performed in a pre-heating device including a chamber containing solid particles, a heat exchanger, a support able to support the semi-finished steel product, a gas injector, and a heating step, performed in a furnace, wherein, the pre-heating step includes the steps of i. injecting a gas into the first chamber so as to form a first fluidized bed, ii. heating the fluidized bed by the heat exchanger, iii. putting the semi-finished steel product, into the fluidized bed and onto the support such the fluidized bed is able to transfer heat to the semi-finished steel product, iv. taking out the semi-finished steel product when its temperature is from 200 C. to 1000 C., and the heating step includes the step heating the semi-finished product to a temperature from 1100 to 1400 C.

A system comprises a furnace, a fluidized bed assembly and a powder bed. The fluidized bed assembly is positioned in the furnace and comprises an outer chamber having an outer chamber inlet for receiving gas, an inner chamber positioned inside of the outer chamber. The inner chamber comprises an inner chamber inlet in fluid communication with the outer chamber, and an outlet through which the gas may exit the inner chamber and the outer chamber. The powder bed is disposed in the inner chamber.