Refractory brick for a glass fusion furnace

A refractory brick, for a heat regenerator in a glass fusion furnace, in the form of a triangular hollow-prism brick body having a uniform wall thickness throughout its length, the hollow interior of the brick body defining a single flow passage extending through the brick body, the single flow passage having a substantially regular triangular cross-section and constituting the entirety of the hollow interior, the brick body having three notches on its lower end and three projections formed on its upper end for engaging the three notches of a like brick whereby relative movement between the plural refractory bricks is avoided when plural refractory bricks are vertically stacked, said notches being significantly larger than said projections so as to leave spaces therebetween forming lateral passages in a plane perpendicular to said single flow passage when plural refractory bricks are vertically stacked, said brick body having three inner round corners and three outer angular corners, the angle of each outer angular corner being 120 degrees, each of said notches being positioned intermediate two corners.