Liquid milk mainly includes ultra-high temperature sterilized milk and pasteurized milk, no matter which kind of product has higher requirements for the sanitary performance of sanitary pumps and valves. Milk contains rich nutrients such as protein and fat, which can easily be contaminated by microorganisms, resulting in corruption and deterioration, so it is necessary to strictly ensure the hygiene and asepsis of the production process. To meet the above requirements, sanitary rotor pumps and valves should have strict tightness.
Sanitary rotor pumps and valves should be made of sanitary stainless steel with smooth inner surface, difficult attachment of microorganisms, convenient cleaning and prevention of secondary pollution.
Sanitary rotor pumps and valves should also have the characteristics of mild handling of materials to ensure minimum nutrient loss in milk. Milk contains sensitive substances such as proteins and vitamins, and if the structure of the valve and sanitary rotor pump enhances the turbulence of the material during flow, then the resulting shear force will destroy these sensitive substances. Therefore, in the selection of sanitary rotor pump and valve should not only consider the flow rate, the flow state of material is a factor that can not be ignored.
The solubility of milk powder is a key index of its quality, and sanitary pumps and valves have an important influence on the solubility of the material. The solubility of milk powder is closely related to the structure, particle diameter and particle density of milk powder. Generally speaking, the particle surface is rough, the particle diameter is large, and its solubility is good. When the sanitary cam rotor pump and valve deal with the material softly, the molecular structure of protein and vitamin in milk is less destructive, so that the milk is easy to form highly soluble milk powder particles after spray drying.
In addition, the good sealing performance of sanitary rotor pumps and valves is very important in the vacuum concentration process of milk. In this process, it is easy to have the problem of too low vacuum, which is caused by many factors, but the leakage of sanitary rotor pump and valve is one of the important reasons. The discharge sanitary rotor pump of continuous concentration equipment works in vacuum. The performance of sanitary rotor pump itself is the key to continuous discharge, and the poor sealing performance can not be discharged at all.
The leakage of sanitary rotor pump will also cause continuous discharge interruption. At present, the shaft seal of the more advanced sanitary rotor pump adopts a unique balanced mechanical seal, and the fluctuation of inlet pressure will not affect the sealing of the shaft seal and prevent the entry of air, so as to ensure the smooth progress of vacuum concentration.
