Patent GB-366551-A (GB)
Title: Improvements relating to blast furnace charging systems
IPC: C21B7/18
Filed: 1930-10-01
Abstract: 366,551. Charging blast furnaces. TRIGGS, W. W., 57, Lincoln's Inn Fields, London.-(Freyn Engineering Co. ; 310, South Michigan Avenue, Chicago, U.S.A.) Oct. 1, 1930, No. 29374. [Class 51 (ii).] . Blast furnace charging apparatus comprises a main charging bell B, an auxiliary charging bell A, and a controller 19, Fig. 2, having selector switches for causing the two bells to operate in a predetermined sequence, the complete cycle consisting of a number of dumps of the bell A, a dump of the bell B, a further number of dumps of the bell A (not necessarily the same as the first number), and a second dump of the bell B, after which the cycle is repeated. The electrical controls are interlocked so as to prevent operation of any part of the charging apparatus until the preceding operations have been completed. Thus, the bell A is not operated until the main bell has fully operated and again closed, and the charging skips ZE are prevented from dumping while the small bell is open, and are stopped if it does not fully open, or if the rotary distributer ZA is in motion. In the apparatus shown, the operating cables D, E, of the bells A, B are attached to vertically movable cylinders H, R with fixed pistons I, S. Pressure fluid is supplied to, and exhausted from, the space above the pistons under control of valves M, W in order to raise and lower them to operate the bells, the valves being operated through arms Q, Z by reversible motors P, Y. Limit switches 47-50 and 51-54 are operated respectively by the arms Q, Z when in their extreme positions. These switches, together with limit switches 32-40 and 42-45, operated respectively by abutments 41, 46 on the cylinders H, R during the movement of the cylinders are included in relay circuits (as shown in the drawings of the Specification) for controlling the sequential operation and interlocking means of the various parts of the charging apparatus. These circuits also include a controller, shown in Fig. 2, comprising a pivoted arm 20 rotated in a step-by-step manner by a reversible motor 31, and shown in position for starting a cycle of operations. Contact shoes 21, 25, 26 on the arm pass respectively over contacts 21a-j controlling the operation of the motor P which controls the movement of the bell A, contacts 25a-j controlling the motor 31 which gives step-by-step movement to the controller arm 20, and contacts 26a-j controlling the motor Y which controls the movement of the bell B. The contacts 26a-j are connected to selector switches 26l-t by which they may selectively be connected either to a ".first dump " bus 29 or a "second dump " bus 30 to predetermine the points at which the bell B is dumped. The operation of the controller is broadly that each downward descent of the small bell operating cylinder H, by closing one of the limit switches 35 or 36 completes a circuit through switch 50 (also closed, since the arm Q is in lowermost position) and the appropriate contact 25a-j to energize the motor 31 and cause it to move the arm 20 one step clockwise on to the adjacent set of contacts. Connections are thus completed through alternative circuits which, after another skip load has been discharged on the bell A, cause successive forward and reverse actuation of the motor P to operate the valve M and cause another dump of the bell A. Operation in this manner continues until the contact shoe 26 on the controller arm 20 is brought on to one of the contacts 26a-j, which has been connected to the " first dump " bus 29 by the corresponding selector switch 26l-t. This completes a circuit causing energization of the motor Y and movement of the cylinder R to dump the large bell B, the circuit of the motor P being meanwhile broken, so that the small bell A cannot operate. On the completion of the dump of the bell B the circuits are restored for further operations of the bell A, each followed by a clockwise step-by-step movement of the controller arm 20, until the shoe 26 is brought on to a contact 26a-j which has been connected by the corresponding selector switch to the " second dump " bus 30. A circuit is thus completed causing operation of the motor Y to produce a second dump of the large bell B, and at the same time a circuit is made through the reverse field winding of the controller actuating motor 31, causing it to rotate the arm 20 in an anticlockwise direction back to the starting position shown.