Patent GB-906394-A (GB)
Title: Mechanism and method for controlling sintering
IPC: G05D5/03
Filed: 1959-08-14
Abstract: 906,394. Automatic control systems for sintering apparatus. UNITED STATES STEEL CORPORATION. Aug. 14, 1959 [Aug. 29, 1958], No. 27924/59. Class 38 (4). A control system for a sintering installation comprises means whereby the amounts of ore and hot recycle together with the speed of the grate are automatically controlled in accordance with the position of the burn through point of the sinter mix on the grate, the settings of the proportions of the additives and water to the sinter mix being manually adjusted. A sintering installation comprises a travelling grate 29 on to which is fed a sinter mix by way of a pug mill 12 and a conveyer belt 28. The ore, the additives and the hot recycle are fed into the pug mill 12 by a second conveyer belt 14, the ore being fed on to the belt 14 from bins 15 and trimmer bins 16, the additives from bins 17 and the hot recycle from bin 18 whilst water is fed into the mill 12 by a line 27. The point at which the sinter mix on the grate 29 burns through is set by adjustment of the slider 55 on a potentiometer 56. The actual burn through point of the mix is sensed by a burn through indicator 39 and any variation in the position of the burn through point from the set position will cause a servomotor 59 to run to seek the null position to determine a new feed rate which is given by the position of the slider 64 of a potentiometer 65. The feed rate signal is then taken to an integrator 66 whereby the effects of minor fluctuations in the position of the burnthrough point are eliminated. The feed rate signal computed by the integrater 66 is taken from a potentiometer 73 and fed to a memory device 75 which runs to position the slider of a potentiometer according to the computed new feed rate which signal is fed to potentiometer 65 to be used in computing a further feed rate signal should the burn-through point alter and to the control mechanism 37 to adjust the feed of ore from the trimmer bins 16. If the alteration in the feed of ore from the trimmer bins is not sufficient then mechanism 38 is operated to effect a change in the feed from the bins 15. The feed of ore on to the belt is also controlled according to the amount of hot recycle fed from the bin 18 which is calculated from signals derived from belt scales 42, 43 which signals in conjunction with a signal derived from another belt scale 41 which gives the weight of ore on the belt 14 is also fed into the control mechanism 37 to keep the sum of the ore and hot recycle feeds to a desired value. Thus any change in the position of the burn-through point on the grate 29 will cause the feeds on to the conveyer belt 14 to be changed, the system including relay and timing arrangements whereby new feed rates are only computed periodically. When the integrator 66 has computed a new feed rate and the new feed rate has been utilized, the integrator returns to its zero position. Manual control of the feed rate can be made by a potentiometer 84. The motor 31 driving the travelling grate 29 is controlled so that the depth of the bed S of the sinter mix is kept to a predetermined value by means of sensing members 34 and control mechanism 33, the arrangement being such that a temporary signal is introduced to return the bed to the desired depth and thereafter to introduce a permanent signal to maintain the desired depth. The control of the depth of the bed is substantially continuous.