An experimental investigation of the effects of baffles on the agitation and removal of manure solids from a liquid manure holding tank

Adequate information on which to base efficient designs of internal baffles in liquid manure holding tanks is not available. Laboratory models constructed to one fifth scale of a prototype liquid manure system were investigated. The agitation nozzle, baffles, and pumping rates were also modeled. Peat moss was used to simulate scaled cow manure. The laboratory test consisted of the following tank arrangements; (1) no baffles, (2) center baffles, (3) side baffles, and (4) side and center baffles. The following conclusions were drawn: (1) the use of the three baffle arrangements decreased the amount of solids left in the tank, and (2) the geometric placement of the agitator nozzle in this study and the use of baffles had a favorable effect on slurry agitation. The least effective was the tank with no baffles, and the most effective treatment was with the side and center baffles.

The results of the test conducted in the model tank were evaluated on the basis of volume of settled solids left in the tank above a slurry base level of 1.5 inches. Based on the volume of solids buildup above the base level, these tests showed that a significant difference in the removal of settled solids existed between each of the four treatments.