Flow-control nozzle for flue-gas scrubber

Claim 1

In a duct traversed by a descending flow of hot flue gases and divided into coaxial upper and lower parts, the upper part of said duct being provided with spray means for irrigating the gas flow with a liquid and being further provided with a stationary central tube extending downwardly from said spray means for the guidance of said liquid, the combination therewith of a flow-controlling nozzle comprising a generally hourglass-shaped tubular body interposed between said parts, said body having a waist substantially narrower than said duct separating a downwardly converging upper portion from a downwardly diverging lower portion of said body, and an insert in said body having a downwardly diverging peripheral surface of generally frustoconical shape which defines with said lower portion a narrow annular channel, said insert being vertically displaceable in said body between several operating positions for varying the width of said channel and being provided with a refractory layer on at least an annular zone of said surface extending above said waist in any of said operating positions, said tube having a bottom edge which lies above said waist and defines with said body a ring space directing the gas flow from around said tube toward said refractory layer.