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.

A method for heating at least one semi-finished metal products to be further laminated, via a heat exchanging device comprising a chamber containing solid particles, supporting means able to support semi-finished metal product and a gas injector, having the successive steps of: i. injecting a gas into said chamber so as to form a fluidized bed, ii. inserting at least one hot semi-finished metal product such that said at least one hot semi-finished metal product is able to transfer heat to said fluidized bed, iii. inserting said at least one semi-finished metal product to be further laminated such that said fluidized bed is able to transfer heat to said at least one semi-finished metal product to be further laminated, iv. taking out said at least one semi-finished metal product to be further laminated of said fluidized bed when the temperature of said at least one semi-finished metal product to be further laminated is less than 100 C. below the temperature of said fluidized bed.