Thermal storage unit including: a receptacle including orifices allowing a heat-transfer fluid to be introduced into and extracted, and a stack of bricks, arranged in the receptacle in superposed strata, each stratum having lower and upper large faces and defining a plurality of ducts opening via lower and upper openings, the stack including a pair of strata of a lower and upper stratum, the upper and lower large faces of the lower and upper stratum being separated to define a passage, placing an upper opening of a lower duct of the lower stratum in fluidic communication with at least one lower opening, entirely offset with respect to the upper opening, of at least one upper duct of the upper stratum, the lower large face of the upper stratum closing off, at least partially, the upper opening, when the upper opening is observed, along its axis, from the lower duct.

A refractory layer structure includes a layer of refractory blocks locked by each other in a tessellated pattern.

A refractory layer structure includes a plurality of refractory layers stacked on each other. Each of the refractory layers includes refractory bricks. Each of the refractory bricks is formed as a cuboid having a pair of oppositely positioned first diverging sides and a pair of oppositely positioned second diverging sides. The first diverging sides diverge away from each other from a top to a bottom of the refractory bricks. The second diverging sides diverge away from each other from the bottom to the top of the refractory bricks. The first diverging sides and the second diverging sides are connected to each other. Each of the first diverging sides have a first diverging side protrusion projecting from a top surface thereof. Each of the second diverging sides have a second diverging side protrusion projecting from a top surface thereof.

A heat storage device such as a hot blast stove including a heat regeneration checkerwork made of checker bricks, the checkerwork being supported by a support assembly (16). In accordance with an aspect of the present disclosure, the support assembly having a carrier structure made of refractory material and carrier floor also made of refractory material, the carrier floor resting on the carrier structure and being arranged and formed to carry the checker bricks of the checkerwork.