Abstract: Pulverized coal feed tanks are emptied in sequence via a transport line into the hot blast of a blast furnace. Each tank is carried by three load cells whose outputs are summed and differentiated to obtain the actual feed rate. Gas pressure in the tank is controlled in dependence on the actual feed rate so as to achieve a desired feed rate. To reduce the possibility of inaccurate feeding of coal, the outputs of the respective load cells are compared, and if deviation from a predetermined weight distribution over the load cells is detected, feed from the tank is stopped. The load cells may be duplicated in series, and the summed outputs of the two sets of load cells compared to detect malfunctioning of a load cell, again resulting in cessation of feeding from that tank.

Abstract: In a support construction for a hot blast main which is connected by respective branches to the outlets of a plurality of hot blast stoves of a blast furnace, the main is suspended on each stove by means of a rod system secured to a stiffened transitional region between the wall and dome of the stove and having an outer end located above the main. The main is suspended from this outer end, to which at least one strut extends from the stove wall adjacent the hot blast outlet. A travelling crane track is secured to the lower side of the rod systems so as to extend above valves incorporated in the hot blast branches. Thus these valves can easily be removed and replaced.