Patent GB-167820-A (GB)
Abstract: 167,820. Jackson, W. J. Mellersh-, (Herman, S. J. and Herman, R. [trading as Diamond Power Specialty Co.]). :May 7, 1920. Cleaning, fluid-pressure processes for.- In a system for cleaning boilers, electrical or fluidpressure means are employed to bring a number of soot blowers, which may be rotated by means of turbines, into and out of operation in succession. As shown in Fig. 1, blower units 1 - - 5 are successively connected with the main steam pipe 9 through branch pipes 8 by way of a multiple-port valve 17 controlled by a clock 18 which operates a solenoid 26 in a circuit with switches 21, 25 adjacent to the blower units. The initial closure by the clock energizes the solenoid to open a valve 27 and admit steam above a spring- controlled piston 28 provided with a plunger 31 linked with an arm 32 loosely mounted on the spindle 33, and provided with a pawl 45 engaging a ratchet-wheel 34 which, together with the valve-plate, is fast on the spindle. The downward movement of the plunger rotates the valve from its neutral position to open the main steam-pipe to the branch pipe 8 leading to the blower unit 1 thus giving access through the pipe 16 to a turbine 12, Fig. 3, controlled by a centrifugal governor 15<a> and mounted in a casing 15 attached to the blower-head. The operation of the turbine rotates the blower head, which is provided with the usual lateral nozzle, through planetary gear 14, worm 13, and worm-wheel 13a. Rotating with the blower unit, is a cam 37 comprising a circular plate with a wide peripheral notch with which co-operates a roller 38 on a bell-crank lever 39 connected by a link 41 with a lever 42 provided with a nose 43 which when the roller 38 is raised depresses a spring- controlled valve stem 44 to admit steam to the rotating blower head. A cut-out 77 opens the switch 21, thereby de-energizing the solenoid 26 and permitting the piston 28 to return to its upper position. The fall of the roller 38 into the peripheral notch of the cam cuts off the steam supply to the blower head and incidentally causes the closure of the switch 21, thereby re-energizing the solenoid 26 to depress the plunger 28 and rotate the valve one step further to admit steam to the blower head 2. The remaining blower heads are similarly operated in succession. In the event of the system being imperfectly drained, water standing in a sump cools the thermostatic valve 48, thus causing the stoppage of the apparatus through the withdrawal of a plunger 48<a>, and opening of a switch 49 in the clock circuit. If, through some defect, the valve has not been returned to a neutral position at the end of a cycle, a number of contacts on the clock drum intermittently close a circuit which is open when the valve is in its neutral position, and by imparting a rapid series of impulses to the solenoid 26 ensure that the valve is returned to its correct position. The cut out for breaking the solenoidcircuit comprises a cylinder 93, Fig. 11, in connection with a branch pipe 76 of the duct 8 and containing a spring-controlled plunger 116 which through a disc 94 with an eccentric aperture. bears against a second recessed spring controlled plunger 95. On admission of steam both plungers move upwards thereby opening the solenoid switch 21 and closing the motor circuit in cases where the blower head is electrically driven. When the lever 41 is disengaged from the cam surfaces 38, the hooked end 118 of the lever 41 brings a trip member 119 downwards to slide the member 41 laterally against the spring 117 until the aperture 115 is in registry with the plunger 116 whereupon the upper plunger falls to close the solenoid circuit prior to the fall of the plunger 116 consequent upon cutting off the steam supply upon the further operation of the valve 17. The steam pressure upon the valve surface is balanced, to avoid jam. ming under high pressure by the provision of a chamber 61, Fig. 6, in connection with the upper part of the steam cylinder 29 and containing a diaphragm 57 connected to a plate 56, against which abuts the extended valve stem 33. In modifications, a steam control is employed in place of the electrical system, and in place of a clock the system is put into operation by the rotating shaft of a mechanical stoker. In a further modification, the blowers are entirely electrically operated and controlled, a rotating drum being provided with main circuit contacts F, F', F<2> ' Fig. 18, contacts H, H<1>, H<2> for the individual boilers and contacts J - - J4 for the individual blowers.