GB1096296A - Method of controlling the operation of moving grate sintering installations - Google Patents

Abstract

<PICT:1096296/C1/1> In a moving grate sintering operation, the input of ore, coke, and returns to the grate is controlled automatically by the use of a first controller (R1) which compares the amount of returns in the returns bin with a set desired value (S1) and produces a signal representing the returns input/ore input ratio necessary to maintain S1, and a second controller (R2) which receives the signal from R1, compares it with a set desired value (S2) of returns production/ore input, and produces a signal representing the coke/ore input ratio necessary to maintain S2; the signals from R1 and R2 are then fed to a calculator (9) which regulates the ore, coke, and returns inputs to tend towards the ratios represented by the signals. Thus, if excess returns are produced, the system adjusts to feed more returns, less ore, and more coke on to the grate, and thus decrease the returns production. Ore from bins 10 and 11, coke from 12, and returns from 5, are fed by means of belt weighing devices B1-B4 on to conveyers 2 and 13, thence to mixing drum 14 and bin 15. The weight of mixture in bin 15 is compared with a desired feed value prescribed by computer 8 and any feed adjustment necessary is transmitted in calculator 9 to B1-B4. The mixture is then sintered on grate 1 (supplied with covering material from bin 16), screened, cooled, and screened again. Returns are recycled to bin 5 e.g. by bucket conveyer. The layer weight (h), and speed (v) of grate 1 (which is adjusted so that final combustion occurs at the end of the grate) are transmitted to computer 8, and used to calculate returns production R (from which S2 is obtained) from the equation F = Av.h-R (where F is the amount of final product, and A is a constant). Preferably S2 (wt. ratio of returns produced to ore input) is 0.3-1 and the wt. of coke input/ore input is 6-8%. If these limits are reached, a signal may be emitted, or the layer height (h) adjusted. The amount of returns in bin 5 may be measured by weight or depth.