New Method to Measure Flow Velocity Based on Short Time Power Spectrum Analysis of Pulp Consistency Noise

Pulp flow velocity is acquired according to time frequency analysis of consistency signal which is measured by consistency sensor during the paper-making process. The method theoretically verifies Doppler Effect of pulp consistency system noise, and detailed procedures to the analysis and processing of pulp consistency signal are proposed. Firstly, the system noise signal is separated from pulp consistency signal. Then it is estimated by the short time power spectrum. Finally the pulp flow velocity is obtained according to the expansion or contraction of time frequency scale. It shows that the method is feasible with high precision and fine dynamic performance, and it can be applied to the occasions of quick velocity fluctuation and high precision.