GB556657A - Improvements in and relating to tube cleaning apparatus for boilers and the like - Google Patents

Abstract

556,657. Cleaning boiler and like tubes. LUMB, C. F., and SPEARS, F. G. W. June 2, 1942, No. 7495. [Class 99 (ii)] In a soot blower in which a steam ejector 11 is reciprocated under the control of a screwed spindle 23 and nut 24, the nut is screwed internally to engage the spindle and externally to engage the steam chest 1 or a fixed casing, so that the reciprocation of the ejector is produced partly by movement of the spindle through the nut and partly by movement of the spindle and nut as a unit through the chest or casing, a stud 43 on the casing or the ejector engaging a straight line and scroll groove 42, 44 in the ejector or the casing. As shown the spindle 23 is actuated by a hand-wheel 31 having tongues 32 engaging notches 33 in a collar 34 on a block 28 pinned to the spindle, which at its inner end has a collar 22 in frictional engagement with a recess 21 in the grooved extension of a piston 19 on the steam ejector. A valve 17 on the ejector normally engages a valve seat 2 to shut off the steam supply, and a joint 20 in the steam chest enables the steam chest and ejector to be detached from the fixed steam branch 10. On rotation of the hand-wheel 31, the spindle 23 moves axially in the nut 24 and opens the steam valve 17 ; on the stud 43 entering the scroll groove 44, a taper portion 38 on the spindle 23 enters a tapered recess 39 in the nut and thereupon the spindle and nut turn as a unit to effect their axial movement through a threaded part la of the steam casing.