Patent GB-759649-A (GB)
Title: Means for withdrawing from stocks related quantities of different materials
IPC: C21B5/00
Filed: 1954-07-02
Abstract: 759,649. Electric control systems. COMPAGNIE GENERALE DES CONDUITES D'EAU SOC. ANON. July 2, 1954 [July 3, 1953], No. 19413/54. Class 40(1) In a system where related quantities of different materials are required, e.g. cast iron, steel and coke for a cupola, a weight of each material approximately equal to the theoretically correct value is taken from stock. These quantities are measured and compared with the theoretically correct values after which more of that material is taken from stock the measured value of which shows a deficiency or the greatest deficiency. As shown, Fig. 3, a potentiometer arm 2 is adjusted to a position C, A or F, according to whether coke, steel or cast iron is being weighed, thereby adjusting the voltage applied to and hence the "scale" of a measuring potentiometer 4, the arm 5 of which is set automatically by the weight of the specific material being loaded. The voltage tapped off at 5, which thus corresponds to the actual weight loaded related to its desired proportion, is applied by a key 6 over a contact K ganged with the potentiometer arm 2 to the corresponding one of the inputs 9, 10, 11 of a comparator 7. The comparator input voltages applied at 9, 10, 11 thus correspond to the actual weights being fed to the cupola of coke, steel and cast iron, respectively, related to their theoretically correct proportions, and the comparator 7 functions to add these "weights" to those already fed, and to light one of three lamps 8 representing the most deficient material related to the theoretically correct proportions. The operation of button 6 automatically empties the weighing hopper, the operator then calling for a load of the material indicated as deficient by the operative lamp 8. Detailed circuitry, Figs. 4, 5, 6. Each operation of the key 6. Fig. 4, energizes a relay 14 for a time predetermined by a timer M, during which relays 17, 18 are energized. Relay 18 locks and as relay 17 falls off with 14, a thyratron 21 is fired and energizes a relay 22 which releases relay 18 to break the thyratron firing circuit. The thyratron is thus fired for a fixed time interval during which comparator condensers Fo, Ao, Co are connected by the relay 22 to their respective amplifiers 36, 37, 38. The potentiometer 1 of Fig. 3 is replaced by three pairs of potentiometers, one pair for each material, only the pair 27, 28 for coke being shown, Fig. 5. One of the relays F1, A1, C1 is always operated to indicate the deficient material. Assuming Cl operated to indicate a coke deficiency, then as relay 14 is energized by the button 6, a relay C2 is energized and equal potentials are supplied from sources V1, V2 to the potentiometers 27 28 which feed equal voltages corresponding to the desired coke proportion (position C, Fig. 3) to the measuring potentiometers 31, 32 which correspond' to potentiometers 5, Fig. 3. The equal voltages derived from the wiper 33, thus correspond to the weight of coke in the hopper (related to its desired weight) and are applied over high resistors 34, 35 for a time fixed by the timer M, Fig. 4, to charge condensers Ao, Co in opposite senses and thus add in the "weight" of coke being fed. Similarly, if relay A1 is operated instead of C1 indicating a deficiency of steel, then A2 is operated instead of C2 and, over contacts thereof equal voltages are applied to condensers Fo, Ao in opposite senses corresponding to the weight of steel being loaded. Similarly when cast iron is being loaded relays F1, F2 are operative to charge condensers Fo, Co. The reasons for charging the condensers in pairs is discussed mathematically in the Specification. As soon as timing relay 14 relapses, the condensers Fo, Ao, Co are connected via amplifiers 36-38, Figs. 4, 6, to respective thyratrons 39-40-41 arranged to be fired selectively according to the most negatively charged condenser Fo, Ao, Co.. The selected thyratron operates its associated relay F3, A3, C3 which via an intermediate relay F4, A4, C4 in turn operates its associated relay F1, A1, C1 to light its corresponding lamp 8f, 8a, 8c indicative of the now deficient material. If none of the thyratrons fire, (indicating correct proportions of the materials loaded), or if two or three fire simultaneously, then the intermediate relays F4, A4, C4 cause the coke indication to take precedence over that of cast iron which takes precedence over that of steel. Total load indication, Fig. 7 (not shown). At each closure of the key 6 auxiliary contacts thereof control through a thyratron a relay which permits a counter to be driven by a synchronous motor for a period proportional to the weight being loaded.