Improvements in or relating to electrically operated sootblowers

878,770. Control of several motors; controllers. JONES, TATE & CO. Ltd. Feb. 28, 1958 [Aug. 28, 1957], No. 27180/57. Class 38 (3). Apparatus for sequentially controlling the operation of several electrically-driven soot blowers comprises means whereby each driving motor is connected as required to a power supply through a common main switch. A distributer is provided with a number of positions in each of which the control circuit of one sootblower is completed, the distrubuter being operated to complete each circuit in turn, and the main switch being opened before the distributer passes from one position to the next. As shown, the distributer comprises seven rings of contact-pairs, each ring consisting of eighteen pairs. A pressure bar 13 closes all the contacts of any row simultaneously, since it has parallel rollers 14 extending the length of the seven rings. The bar 13 is actuated by a ratchet 15 which is secured to arm 17 and rotated by solenoid 16, energization of the solenoid causing link 23 to move arm 22 clockwise, whereby a pawl pivoted to the bar engages a tooth in the ratchet. A further pawl is pivoted to a fixed member 21 for preventing reverse rotation of the ratchet, and both pawls are spring-urged to the engagement-position. A three-limbed member, Fig. 1 (not shown), prevents over-shooting of the pressure bar 13. When the ratchet has reached a desired position, one limb engages a fixed stop, and any further tendency for the bar to rotate causes another limb to engage a tooth of the ratchet. A spring is connected to the third limb for disengaging the second limb from the ratchet. The arm 22 is adapted to operate a heavy-duty switch which always opens before the distributer contacts to interrupt the motor-circuit. The arm also actuates a time-delay switch for ensuring that successive movements of the pressure-bar have an adequate time-delay between them. Each sootblower has its own motor M3, two-position sequence switch S3 for determining whether the sootblower is to be operated or by-passed, indicating lamp B3, and limit switch L3, the distributer D being shown in the condition at which the operation of the third sootblower is initiated. If the pressure bar is lying along the eighteenth row of contacts, the sequence is started by closing switch E to energize relay R, so causing solenoid O to move the pressure bar on to the first row. Contacts O1 open to disconnect the main contactor P, and contacts 02 open subsequently to de-energize relay R,