Operation and hydraulic modeling of a dairy flush system

Model studies were conducted on the effect of slope of the concrete alleyways in dairies on the efficiency of manure removal from alleys by flushing. Peat moss was used in an attempt to simulate cow manure in a distorted hydraulic model of an alley, but the physical behavior of the peat moss was not similar to manure because peat moss does not have the adhesion qualities of cow manure. Therefore, the experimental determinations were made using cow manure.

The hydraulic model of the dairy alley was distorted with a vertical scale of 1:1 and a horizontal scale of 1:10. model to prototype.

Boundary layer theory, dimensional analysis, and the Buckingham Pi Theorem were used in developing the similar model. The model was calibrated from comparisons of a prototype alley flush system at the West Tennessee Experiment Station in Jackson. Seven significant equations for the system were established and these might be used in future prediction of manure transport in dairy alleys cleaned by flushing. Predictions on which alley flush designs may be made were presented. The results of the laboratory tests conducted on the model showed that the suspended load of manure in the alley flush per unit time and per unit of length was characteristic of the condition.

The results showed that the slope of the channel was the major factor affecting flushing system efficiency as well as the velocity of the flow of the flush water. An alley slope range of 3 to 4 percent was found to give high alley flushing efficiency.