NOZZLE FOR REMOVING BASE METAL OF OXYGEN INJECTION LANCE

摘要

A decimating time discrete filter comprises transform means (2) for transforming a real valued input signal (i) into a complex signal (u) represented by its real part Re{u} and its imaginary part Im{u}. The output signal (u) is down sampled by means of a decimator (4) which reduces the sample frequency by a factor of 2. Due to the downsampling process, a desired tone input signal can be translated to a different frequency. In order to prevent interference from signals at the input having the same frequency the desired input signal, in the prior art filter a Hilbert transformer (8,b) is used as transform means (2). In the filter according to the invention, the transform means (2) have a transfer function with a increased width transition band from the frequency of the desired input signal to the frequency to which said input frequency is converted.