Determining the efficiency of cleaning a milk line made from different materials from contaminants

While moving along the milk-conducting systems in a milking machine, milk is in contact with the inner surface whose area exceeds 20 m2. That leads to the formation of protein-fat biofilms of contamination, which are a nutrient medium for the development of microorganisms. With insufficiently effective cleaning of these contaminants, in the periods between milking, the number of microflorae located in milk-conducting systems increases by tens of thousands of times. When cleaned with ineffective cleaning agents, mineral elements from milk are adsorbed on the surface of a protein-fat bio-film, which are subsequently compacted, changed, and converted into milk stone. In this case, the technical implementation of milk conducting systems is of critical importance. It has been established that a milk line made from any material is better cleaned with a hot washing solution than a cold one. Thus, with an increase in the temperature of a washing solution from 60 °C to 85 °C, the cleaning time of the milk line is reduced from 9.5 minutes to 1.5 minutes, or by 6 times. It was established that during the washing phase of a milk line there is a significant decrease in the temperature of the washing solution (≈30 %), which reduces the effectiveness of cleaning the parts of the system. Therefore, there is a need to maintain the solution temperature throughout the entire cleaning process. It is proved that the specific energy of adhesion of pollution in water is 2 times higher than that in a washing solution. With an increase in the temperature of the solution for every 10 °C, the decrease in the specific energy of pollution adhesion is on average 13 %. With an increase in the period after the end of milking before washing the milk line, the specific energy of its purification increases. The study reported here could lead improve the productivity of milking machines and the quality of the resulting product. That involves designing milking and dairy equipment from innovative materials.