METHOD FOR CALCULATING THE PARAMETERS OF THE VORTEX CHAMBER OF THE ACTIVE HYDRAULIC DRIVE OF OIL CLEANING CENTRIFUGES
Full-flow centrifuge for cleaning of technical liquids with active vortex hydraulic drive is considered. Hydraulic drive is radial-axial centrifugal turbine. The guide vane is a cylindrical vortex chamber with tangential inlet channels. It forms a flow of liquid that rotates and conically diverges at the outlet. Turbine impeller is installed in rotor. Its blades and channels are located at the same taper angle. The problem of designing a vortex chamber is solved to ensure the required rotation speed of the centrifuge at a given fluid flow rate in the hydraulic drive. The optimal geometric parameters of the vortex chamber are determined: its height, radius, as well as the number and width of tangential inlet channels, the radius of the outlet hole from the vortex chamber. A calculation algorithm is proposed. First, radius of outlet from vortex chamber or inlet to turbine impeller is determined. It is based on the condition of equality of the driving moment developed by the hydraulic drive and the moment of resistance of the rotating rotor. Formulas are given for calculation of moving moment and resistance moment taking into account resistance in cylindrical seal of vortex chamber connection with rotor. An equation is obtained for calculating the radius of the outlet of the vortex chamber depending on the flow rate of liquid. Then there is internal radius of vortex chamber on condition of minimum loss of kinetic moment of liquid in it. By operating on the width and number of inlet channels of the chamber, their height is determined based on the condition of minimum hydraulic losses in the vortex chamber. Results of calculation of moments of rotation resistance of rotors of different sizes and optimal radius of outlet hole from vortex chamber at different flow rates of liquid are given. Parameters of the vortex chamber of the experimental centrifuge were calculated. Its tests were carried out. Their results confirm the effectiveness of the developed procedure for designing a vortex hydraulic drive. Conclusions and recommendations on optimization of geometric parameters of vortex hydraulic drive of cleaning centrifuges are formulated.