Abstract: A ventilation device may include first and second supply ducts, a mixing section having a mixing duct into which the first and second supply ducts may lead, the first and second supply ducts arranged in the mixing section adjacent one another in a transverse direction, and first and second guides in the mixing section each running in the transverse direction and being located opposite one another in a longitudinal direction running transversely to the transverse direction, each guide having two guide walls running in the transverse direction and located opposite one another in a height direction running transversely to the transverse direction and longitudinal direction, at least one of the guide walls sloping away from the other guide wall at a slope angle with respect to the longitudinal direction.

Abstract: A ceramic burner for the combustion chamber of air heaters and the like has a mixing body composed of layers of shaped ceramic bricks, the shaped bricks adjoin each other with radial flanks and engage and mutually interlock with one another by knobs or protuberances and corresponding recesses. The layers of shaped bricks are held together vertically by a ceramic bolding bar. In assembly, the mixing body has a mushroom shape wherein the upper layer shaped bricks have a larger radius than the lower layers.

Abstract: A refractory brickwork wall having an opening therethrough has incorporated therein, at a position above the opening, a relief brickwork configuration in the form of a gable or roof. The relief brickwork includes a plurality of relief bricks each having an upper inclined surface, a lower inclined surface and a lower, generally horizontal step surface. The relief bricks are arranged one above the other in an inclined formation with the lower inclined surface of the upper relief brick of each pair of adjacent relief bricks resting on the upper inclined surface of the lower relief brick of such pair of adjacent relief bricks, and with the upper relief brick of each pair of adjacent relief bricks being partially offset in a horizontal direction from the lower relief brick of such pair of adjacent relief bricks.

Abstract: A burner includes a central burner duct for passing combustion gas therethrough and an outer annular duct for the passage of combustion air and coaxial to the central burner duct. The ducts open or join at an opening area, upstream of which are one or two areas where the combustion gas and air are combined or brought together and mixed. A disk-shaped mixing element is positioned within the opening area centrally thereof and downstream of the first combination area and adjacent the second combination area. The mixing element has extending therethrough substantially in the direction of flow, a ring of separate passages.