Improving the design of a vacuum pump for milking units

Abstract

The analysis of the existing and new technical decisions which promote increase of efficiency and reliability of work of vacuum pumps of milking units is resulted. Review and comparative evaluation of existing milking equipment and installations, indicates the feasibility of using in their composition rotary vane vacuum pumps as a power element. Compared to others, they have a fairly high efficiency (0.8-0.9), low energy consumption (0.06-0.08 kWh/m3), simplicity of construction and maintenance, the possibility of direct connection to the motor. In the pump housing, the inlet and outlet pipes of the pump to the working chamber are located (in the cross-sectional plane) close to the radial direction. In this case, the inlet and outlet windows have a length (in the direction of rotation of the rotor), and along the axis of the housing, it is close to the diameter of the respective nozzles, and the length of the air compression zone is significantly increased and is almost 180o. The disadvantage of this solution is to reduce productivity and increase energy consumption.
The conducted graphic modeling, analysis and generalization of known technical solutions and results of researches of working process of vacuum pumps of rotary type, concerning substantiation of their design and technological parameters, allow to note that for achievement of the set purpose it is expedient to make such changes in a vacuum installation design:
• increase the volume of the intake and exhaust chamber on the inner surface of the vacuum pump housing.
This solution allows the volume created between the two rotor plates to be filled with air faster and to provide a fuller exhaust. These conditions help to increase the performance of the pump at the same values of the diameter of the rotor and its speed;
• place the inlet and outlet pipes in places where the forces acting on the blade provide maximum pressure to the rotor body (as the rotor rotates in the plane of its cross section), and increase the length of the inlet and outlet windows to such an extent that the angle between blades provided capture of windows;
• minimize the length of the air transportation and compression zone.