Arc furnace boiler bases - using shapes which can replace expensive spherical bases

摘要

Base for a furnace boiler, esp. an arc furnace boiler, the novelty being that at least one part of the base forms a developable surface. The pref. surfaces are (a) a curve, i.e. a segment of a circle; or (b) a segment of a polygon resembling the arc of a circle; or (c) is formed by two pieces, each consisting of part of a cone or a pyramid. The invention is desired to replace the spherical bases normally employed to provide the required rigidity and strength on pressurised boilers, because such spherical bases are expensive to mfr. The new bases provide the rigidity required, but are simple and inexpensive to mfr., as neither hot forge-pressing nor special machines are necessary.