| 摘要 |
<p>The present invention relates to a method for preheating the scrap by reheating the exhaust gases and to a device for performing the method. In a device that is known in the art and is described in EP-C-0190313 there is a melting furnace (1) into which a feeder channel (3) for the scrap (4) leads (figure 1, which shows the prior art). The exhaust gases produced in the furnace (1) are made to flow in countercurrent in the channel (3) and are aspirated by the aspirator duct (8). In order to cause the combustion in the channel (3) of the combustible gases contained in the exhaust gases and preheat the scrap (4), the channel (3) has a series of air feeder nozzles (9) distributed along the channel (3). In this device, however, it is not possible to obtain a flame along the channel (3) and therefore the preheating is insufficient. According to the invention, in order to improve the combustion of the gases in the channel (3), one takes into account, in terms of method, the propagation of the flame along the channel (3), which is controlled. This is achieved, in terms of a device, by virtue of the system of concentrating the air feeder nozzles (11) in a single point of the channel (3) that is arranged in the vicinity of the melting furnace (1), where the nozzles (11) then direct their jet of air so as to increase the flame propagation rate along the channel (3). In a preferred embodiment, two types of nozzle (11') and (11'') are used: one (11') blows the comburent air at right angles to the direction of the exhaust gases in the channel (3), and the other one (11'') blows the comburent air parallel to, and in the same direction as, the exhaust gases in the channel (3). <IMAGE></p> |
