The Study On Emulsion Concentration Measurement Online For Cold Rolling

During the process of cold rolling, emulsion usually plays an important role in cooling and lubrication as lubricant. The emulsion concentration is a key item on the physical-chemical specifications. The functions of emulsion will be affected due to its concentration's large variation. It is very necessary of mearsuring and controlling the emulsion concentration in the scope of the target value. So the emulsion concentration measurement online is very important. Firstly the newest domestic and overseas general developing situations of inspecting techniques in liquid concentration are summarized in detail. According to the physiochemical properties of emulsion, the essential properties of these techniques are analyzed, as well as problems occurred in inspecting concentration online. Meanwhile, the key problems that should be solved on application are presented. Secondly the relation between emulsion concentrations, temperature, pressure, and ultrasonic velocity is discussed when we use pulse-echo sound speed method of ultrasonic to measure its concentration. Through setting up models, the ultrasonic transmitted velocities that associate with the emulsion concentration ranging from 0 to 11 percent and with the temperature ranging from 20℃to 65℃are calculated. In addition, when the emulsion is adulterated with particles of iron, how they disturb the measurement results is analyzed in detail. Furthermore, a method to reduce the disturbance of the iron particles is put forward. Based on the theory analysis of the concentration measurement, the main project of measurement system is put forward. Its core of hardware system is micro-single-chip C8051F005 and CPLD MAX3064ATC44. The designs of the ultrasonic transmitting / incepting circuits, waves zero-cross detecting circuit, temperature measurement and man-machine interface circuits are introduced in detail. According to the difference of the functions about micro-single-chip and CPLD, their designs of software and their softerware interfaces of bus-mastering are described respectively. The prototype in principle is designed and the system software is completed. At the same time the methods of polynomial and the linear are put forward in order to decreasing error in measurement. The emulsion concentration in Wuhan Iron & Steel Co. is measured in term of these theories. The results show that the error and detecting time in test can keep up with the online measurement requirement, and the system stability is favorable.