Integrated Measurement Of Pulp Consistency And Pulp Flow Based On Sparse Decomposition

The pulp flow and pulp consistency are two physical quantities which are measured frequently in paper production. The real-time accurate performance of pulp flow and pulp consistency’s measurement are very important to improve efficiency and production effecs in pulp washing and pulp flow, and also important to ensure the quality of pulp and paper as well as in production cost savings. The electromagnetic flow-meters have been used most frequently, but the price is higher, and the core technology is still in the stage of confidentiality. Mechanical consistency sensors are used mostly in the production line, but they are often affected by noise interference in practical measure process which cause poor precision in pulp consistency measuring. This paper proposes a method to sparse decompose pulp consistency, analyze sparse atomic scale and sparse representation of inherent noise. Then the pulp flow and high precise pulp consistency can be obtained with consistency sensors. The main work of this paper is as follows:(1) The specific composition of pulp consistency signal and its corresponding properties are researched. Via the research of pulp existing form and measuring principle of mechanical type consistency sensor, the specific composition of pulp signal is derived. Then the specific composition is separated and analyzed one by one to prove and validate the inherent noise in consistency signal. The inherent noise is different from other internal components’multiple properties, which has Doppler effect, scale features and so on. These results provide theoretical support for the following work.(2) The pulp flow measurement method based on sparse decomposition is proposed. According to the characteristics of pulp consistency inherent noise signal, a complete atom library with scale properties to sparse representation of inherent noise is established. Then formula of pulp velocity is obtained by calibration. Furthermore, the pulp flow is derived. In addition, the feasibility of pulp flow measurement by consistency sensor is proven.(3)High precise measurement of pulp consistency based on sparse decomposition is researched. According to the characteristics of measured noise signal, a nonscale feature atomic library to sparse representation of measured noise is established. Then the inherent noise and measured noise are separated from pulp consistency signal. The pulp velocity value is used to compensate the pulp consistency. Eventually, higher precise pulp consistency is derived.(4) The integrated measurement system of pulp consistency and pulp flow is designed and implemented with the design of hardware and development of software, the integrated measurement based on DSP is realized, which can measure pulp flow value and high precise pulp consistency value by using pulp consistency sensors.Through above research, the pulp flow value could be obtained and the pulp consistency’s measurement precision could be improved by consistency sensors. On the premise of ensuring accuracy and real-time performance of measurement, the cost of system could be reduced greatly to provide technical support for its popularization and application.