Study On The Mechanic Of Variable Aperture And Dynamic Filtering And The Fuzzy Control Method To The System

Filtration is an old and new topic. Among all kinds of filtering problem, how to filter the superfine material is a very important question which is studied by engineers from all country. People usually use the deep level filter method to filtrate the superfine material, but the deep level filter method has its limitation. At first although that we can increase the filter efficiency by decrease the grain size of the filter material, we can抰 do that over a limitation. And the grain size of the filter material can抰 decrease endless. Second, we have to change the filter material according to different liquid and different requirement. So when the liquid changes, the filter material has to change. Further more, there are some difficulties for clean the traditional grainy filter material, the clean will also cause the loss of the filter material. So several years ago, some people advice that we can use some kind of material whose aperture is variable to take the place of the traditional grainy material. Mr. hutian in Japan advise that we can use some bundle of fiber which is tied together as such kind of filter material. When filtrating, we can make it compact, which ensure the filter efficiency. When cleaning, we can make it loosening, which ensure the clean result. The application of the fiber filtering material improves the technology of filtration a lot. Engineers in all countries exploit on it, and have developed it. But most of the application is under the static condition. It inevitable has the problem that after a period of the filtering process, filter impurity will stay on the surface of filter material, and it will accumulate and become filter cake, the filter cake will become more and more thick, at last it will do harm to the filter efficiency and filter accuracy. So this text III is aimed to solve this problem. We introduce the dynamic filter mechanic to the static deep level filtration, and study on the filter mechanic and control method for fiber filter material under dynamic condition. The following are works we have done in this text. 1. Introduce the history and development of filtering technology, and put forward the subject about the mechanic of variable aperture and dynamic filtering and the fuzzy control method to the system. 2. We have compared the traditional filter material with the new fiber filter material. We have also studied the cleaning mechanic of fiber filter material by using a new drag theory. 3. We have established the liquid dynamic model for the variable aperture dynamic filter process, both under static condition and dynamic condition. We also calculate the finite difference Navier-Stoke equation for incompressible viscous fluid under dynamic condition. 4. We have done some studies on the filter technology and the structure of variable aperture dynamic filter. 5. By using fuzzy controlling method, we have studied on how to control the variable aperture dynamic system. We also do some emulating study by using the simulate tool of Matlab. 6. We have also done some experimental investigation on the variable aperture and dynamic filter technology. Amend the dynamic model, probe into the relationship among concentration of slurry, pressure of fiber filter material, average grain diameter, rotational speed of filter cartridge, filtering velocity, filter accuracy, fil...