Reducing noise emission during chipper operation. 1. Measurement data, noise sources, positioning and outfitting. 2. Noise reduction methods
Hulshorst, H.; Wurzel, W.
Holz-Zentralblatt 111(146; 148): 2154-2156; 2176, 2178
In part 1, the acoustic pressure, noise emission pattern, and noise frequency are reported of (a) knife-ring chippers, (b) hoggers, and (c) rotating-knife chippers under no-load and loaded conditions. Acoustic pressure (in operation) ranged from 102 to 112 dB(A) in (a), 89-104 dB(A) in (b), and 88-103 dB(A) in (c). Reduction of noise emission by encasing or spatial isolation of chippers is outlined. In part 2, primary (structural) and secondary noise reduction methods are discussed in detail.