Abstract: The invention relates to a method for the direct reduction of oxidic iron carrier particles to a reduction product in a fluidized bed through which a reduction gas containing 30-100 mol % hydrogen H2 flows in crossflow. At least 90% by mass of oxidic iron carrier particles introduced into the fluidized bed have a particle size of less than or equal to 200 micrometers. The superficial velocity U of the reduction gas flowing through the fluidized bed is set between 0.05 m/s and 1 m/s such that, for the particle size d equal to d30 of the oxidic iron carrier particles introduced into the fluidized bed, it is above the theoretical suspension velocity Ut and is less than or equal to Umax.

Abstract: The invention relates to a method for the direct reduction of oxidic iron carrier particles to a reduction product in a fluidized bed through which a reduction gas containing 30-100 mol % hydrogen H2 flows in crossflow. At least 90% by mass of oxidic iron carrier particles introduced into the fluidized bed have a particle size of less than or equal to 200 micrometers. The superficial velocity U of the reduction gas flowing through the fluidized bed is set between 0.05 m/s and 1 m/s such that, for the particle size d equal to d30 of the oxidic iron carrier particles introduced into the fluidized bed, it is above the theoretical suspension velocity Ut and is less than or equal to Umax.

Abstract: A heat storage system using sand as a solid heat storage medium has a fluidized bed heat exchanger (3) arranged between and separated from a storage tank (1) for cold sand and a storage tank (2) for hot sand by weirs (4, 5). The heat exchanger (3) is divided into a plurality of chambers (7) by weirs (6). The weirs (4, 5, 6) are arranged as a combination of overflow and underflow weirs. Fluidized sand is produced in the chambers (7) by a blower (14) positioned underneath the heat exchanger (3). Heat is transferred from a heat source to the sand fluidized and from the fluidized sand to a heat transport medium by transferring mechanisms (8, 9) in the chambers (7). The sand is redirected in a horizontal direction by horizontally acting blowers and/or installations (12) projecting into a respective chamber from a side.

Abstract: The invention relates to a heat storage system using sand as a solid heat storage medium, characterized in that it comprises the following components: a storage tank (1) for cold sand; a storage tank (2) for hot sand; a fluidized bed heat exchanger (3) arranged therebetween, which is separated from the storage tanks (1, 2) by weirs (4, 5) and divided into a plurality of chambers (7) by weirs (6), wherein the weirs (4, 5, 6) are arranged as a combination of overflow and underflow weirs; wherein means (8) for transferring heat from a heat source to the sand fluidized therein as well as means (9) for transferring heat from the sand fluidized therein to a heat transport medium are provided in the chambers (7) of the heat exchanger (3); and at least one blower (14) positioned underneath the heat exchanger (3) for fluidizing the sand.