Device for the acoustic damping of a radiant-heating tube for an industrial furnace

Claim 1

In a fuel-fired radiant-heating tube assembly for an industrial furnace in which a radiant-heating tube has an end projecting through a furnace wall, a fuel-feed pipe extending into said tube at said end, a combustion air fitting at said end for delivering air to said tube, and an exhaust gas outlet at said end for leading combustion exhaust gas from said tube, the improvement which comprises: an acoustic damper connected to said outlet, said damper including an elongated insulated outer shell, an elongated inner shell disposed in said outer shell and defining an elongated outer annular passage therewith, and a core body disposed in said inner shell and spaced therefrom to define within said inner shell an elongated annular inner core passage; means connecting said outer passage to said outlet for traversal by said exhaust gas; means connecting said inner passage to said fitting for traversal by said air whereby said air is preheated in said other passage in indirect heat exchange through the wall by said inner shell by said exhaust gas; and thermally conductive acoustic-damping elements in said outer passage for limiting sound generation by said exhaust gas and conducting heat to said inner passage.