National Research Tomsk Polytechnic University (Tomsk, Russia):

Tomilin A. K., Professor, Doctor of Physical and Mathematical Sciences, Professor, aktomilin@tpu.ru
Pashkov E. N., Associate Professor, Candidate of Engineering Sciences
Ziyakaev G. R., Associate Professor, Candidate of Engineering Sciences, Associate Professor

Increasing the rotor speed with a transition to the supercritical region allows improving the performance of a gas centrifuge by tens of percent. Another option enabling performance improvements for mineral processing equipment is the transition to multi-section centrifuges, when several rotor-cylinders are coaxially located on a single shaft. In a multi-section centrifuge, the shaft length is significantly longer than in a single-section centrifuge, therefore, the imbalances caused by elastic deformations of the shaft increase significantly. The use of automatic balancing devices (ABD) allows eliminating this problem. The aim of the study consists in an analytical description of vibrations of a two-section rotary centrifuge taking into account the elastic deformations and a calculation of the required balancing force of the ABD. The centrifuge is modeled as a system of two absolutely solid rods connected in series with an elastic element (bellows) and fixed in elastic bearings at the top and bottom. This system has three degrees of freedom. Respective kinetostatic equations have been compiled and critical frequencies have been established. The shaft deformations have been calculated at an operating rate exceeding the third critical rate for the given static imbalances. Particular cases of various ABD locations were investigated, when installed at the level of the upper and lower bearings and at the connection of the cylindrical sections. In all cases, the values of the force created by the ABD and the residual dynamic deformations have been established. It has been shown that the latter case is the most effective. The results of the work may be used to simulate the dynamics of high-rate twosection centrifuges with various technical specifications in order to solve the related dynamic auto-balancing problems.

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