Vacuum Fluctuation in a 2×3 Tandem Milking Plant in Dependence on the Vacuum Control Method

Abstract

Vacuum fluctuation was measured using three different vacuum control methods. Firstly, the use was made of a control valve delivered by the manufacturer; then, an additionally installed frequency converter was used. Lastly, a frequency converter fitted with the stabilisation device prototype was used. First, the control sensitivity according to ISO was measured in all three alternatives. Then the vacuum fluctuation during milking was measured. To conduct the measurements under objectively identified conditions, another measurement was conducted with the air feed during milking being replaced with a precisely defined variable flow rate. The conducted measurement confirmed the fact that when the frequency converter is used, the vacuum fluctuation in the stabilised condition is at the same level as when the control valve is used. If there are sudden changes in the flow rate and the frequency converter is used, the vacuum fluctuation increases. The proposed stabilisation device prototype can reduce the fluctuation.

Keywords

• vacuum fluctuation
• vacuum control methods
• frequency converter