Study On Superfine Grinding Of Material Based On Ultra-pressure And Impinging Theory

Firstly, based on the technology of the superfine grinding, this thesis discussed the application, station and function in the national economy and the actuality of the technology of the superfine grinding at home and abroad. Then, considering relative theory of wet method superfine grinding, the microchannel of the homogenizing pipe, as subject investigated, is divided into five parts: leading zone, separation zone, impinging zone, compel jet zone and expanding zone. The different crushing acting forces imposed on the material in the five zones were analyzed serving as a theoretical base for designing the homogenizing pipe reasonably. Moreover, we modeled and simulated the inner flow flied of the homogenizing pipe and got the basic distribution of relative physical quantity. From analyzing, we knew that the velocity and the velocity grads should be very tremendous, and the change of the static pressure be very great after impinging, which brought huge force in the flow flied and caused a perfect crushing effect. After that we also discussed the broken wall technology of glossy ganoderma spore as an example. We modeled the distribution of the stress of the glossy ganoderma spore wall under the ultra-pressure with the finite element method (FEM). And found that the stress of the middle spore wall is maximum which brings stress concentration there and results in crushing easily. Moreover we find that the on-load pressure is approximately directly proportional with the maximum node stress of the spore and the broken wall effect of spore is better and better with the on-load pressure increased continuously. At last, through tentatively modeling the impinging course of spores with FEM using ANSYS/LS-DYNA software we could see intuitively that the change of the stress and meet an emergency of the spores during the course of impinging. The force between spores we calculated was used to explain that the greater force loaded and the faster velocity of impinging run, the better crushing effect would be caused. This research could provide a reference basis on designing of the homogenize-head, which is a key part of the superfine grinding equipment, and scientific basis for future development.