Disc Spiral Centrifuge Dynamic Characteristics Calculations And Balance

The Disc Decanter which has discs in a decanter is a new centrifuge developed by Dorr-Oliver in 1994, combining the beneficial features of a disc centrifuge and a decanter providing clear overflow and dry cake. It has fully applied in the advanced industrial countries of Europe and U.S currently. If we China first produce this new centrifuge in whole Southeast Asia by using its advanced design technology and experience, it must have broad market prospects. But compared to the foreign technology, our country has not yet reached the manufacture and assembly of high precision, which lead the eccentric mass of the manufactured centrifuge to produce centrifugal forces and couples. The unbalance forces will cause vibration and even invalidation of the machine finally. Especially for the multi-rotor and multi-speed disc-decanter centrifuge, its unbalance state is more complex. So the dynamic balance of disc-decanter centrifuge during manufacturing or use is of great importance, which has been earlier focused by manufacturers.For the research of dynamic balance of this kind of rotating machinery, the accurate calculation of rotor dynamic behavior is a key aspect, which can provide evidences for the manufacture, improvement on structure design and dynamic balance of the machine. The main aspects of the research work done in this paper are: first, the working principle, structural characteristic of a disc-decanter centrifuge and the research background of this paper are introduced; Second, based on the basic principles of FEA about rotor systems, a self developed finite element equation of dual-rotor system is given, which provides theoretical reference for the dynamic characteristic of the dual-rotor system; And then, the function of ANSYS is introduced, a program was developed by Ansys Parametric Design Language - APDL, through which the dynamic characteristic of rotor-sliding bearing model and dual-rotor model is verified to make sure the reliability when the calculation program is applied to of disc-decanter centrifuge; At last, parametric program of modeling, loading and calculation of the disc-decanter centrifuge through APDL is developed, the calculation of dynamic characteristic including critical speeds, vibration mode, unbalance response and the analysis of influencing factor for single-rotor and tri-rotor system is done, and reasonable dynamic balance method of single-rotor and separating method of the "beat" signal in whole machine are put forward in theories.