Patent GB-844675-A (GB)
Title: Improvements relating to the reversing mechanism for regenerating ovens
IPC: C10B21/14
Filed: 1959-02-10
Abstract: 844,675. Thermal regenerators. KOPPERS G.m.b.H., H. Feb. 10, 1959 [Feb. 10, 1958; April 5, 1958], No. 4698/59. Class 64(1) The gas valves of a regenerative oven are operated in sequence by reversing mechanism comprising rocking levers each connected by draw members 12, 12a (Figs. 4 and 5) to the valves (not shown), each such lever having a driving element such as a tooth, pin, roller or the like co-operating with a driving wheel shaped to cause corresponding movement of the driving element with consequential rocking of the lever during part of the revolution of the wheel in either direction and, during the remainder of such revolution to lock the lever against rocking. The invention is described in its application to a horizontal coke oven battery heated by combustion of rich or lean fuel gas and preheated air, control of the valves regulating the flow of these gases to and from the regenerators being effected by two sets of reversing gear one at each side of the battery (Figs. 1 to 3, not shown). Each set of reversing gear comprises three rocker levers 5, 6, 7 pivoted on a shaft 9 and actuated in sequence by cams 26, 27, 28 carried on a shaft 18 rotated intermittently by manual or power drive in alternately opposite directions to open and close the gas and air valves as required. In the form shown each cam comprises two profiled discs each of which co-operates with one or other of a pair of rollers 34, 35 on the lever arm as the shaft 18 is rotated. Fig. 8 shows the starting position and Figs. 9 to 11 show successive stages reached during rotation in direction 37 of the shaft 18 in a reversal taking place at the end of a heating period during which the levers 5, 6 and 7 have been in the positions shown in Figs. 4 and 8. It will be seen from Fig. 8 that discs 26a, 26b of cam 26 are so orientated that the end wall 36 of recess 30a of cam disc 26a is abutting roller 35 whilst roller 34 is just on the trailing end of a cylindrical locking surface 29b of cam disc 26b. Hence rotation of shaft. 18 in direction 37 rocks, lever 5 in direction 38 (Fig. 4) the rocking torque being imparted by wall 36 acting on roller 35 whilst roller 34 moves into a recess 30b on cam disc 26b. Fig. 9 shows the angular position of cam discs 26a, 26b immediately after lever 5 has reached its new end position whence it will be seen that roller 35 is now positioned to run over the locking surface 29a of cam disc 26a which accordingly acts to hold the lever 5 in its new end position during further rotation of shaft 18 to operate the remaining levers. Owing to the phasing of cams 26, 27, 28 on shaft 18 lever 5 is rocked prior to movement of either of the other rocking levers 6, 7 but when lever 5 reaches its new end position shown in Fig. 9, cam 28 will have rotated to bring wall 36 of recess 30a in cam disc 28a almost into engagement with roller 35 of lever 7 so that there will be a short pause before continuing rotation of shaft 18 causes similar rocking of lever 7 to reverse the condition of the waste gas and combustion air valves. During this pause, fuel gas downstream of the now closed fuel gas cocks is swept through the heating system and burned in the flues thereof. During rocking of lever 7 between its end positions movement of its associated drawmember 12 momentarily opens the decarbonizing air valves to effect decarbonization of the rich fuel gas nozzles if the battery is being operated on rich fuel gas. Following rocking of lever 7 into its new end position (Fig. 10) by continued rotation of shaft 18, the lever 6 is rocked to open the previously closed fuel gas valves. Thus, as seen in Fig. 10, when lever 7 has reached its new end position the end wall 36 of recess 30a in cam disc 27a will have come into engagement with roller 35 of lever 6 and hence continuing rotation of shaft 18 rocks lever 6 to a new end position shown in Fig. 11. The subsequent reversal is effected by rotating shaft 18 in a direction opposite to that of arrow 37, from the position shown in Fig. 11 to that shown in Fig. 8. In another form of rocking lever described, a cylindrical rocking surface is necessary on one only of the cam discs actuating each lever. In a further form only one cam is associated with each lever which only requires one roller.