Parameter optimization of milk pulsation homogenizer

Abstract

Homogenization is one of the normative processing stages in dairy foods production. One of the topical problems of the modern food industry is to design energy effective equipment for homogenization of milk emulsions. The perspective method to intensify milk fat phase dispersing is to improve pulsation homogenization. Such machines combine high energy efficiency and dispersion degree which exceed the indexes of valve homogenizer. The aim of researches is to decline power consumption of the process of milk pulsation homogenization by optimizing its parameters. Experimental pulsation homogenizer has a piston with openings which performs sinusoidal oscillations in the cylindrical chamber and is driven by crank gear. The product is supplied into the homogenizer by the volumetric pump. Creating high velocity relative slip between a fat globule and milk plasma causes size reduction of the milk fat. To find out the optimal parameters of the process the graphic methods of the local optimization are used. Emulsion dispersion degree was determined by measuring fat globules sizes by optical microscope with digital camera. Conducted researches on the pulsation homogenizer showed high correlation between the acceleration of emulsion and fat globules average size. The analytically got results are experimentally confirmed on increasing dispersion degree whereas the specific energy consumption declines and piston oscillation frequency increases. Using conical openings of the piston compared with cylindrical ones makes it possible to reduce energy consumption of the homogenizer. Decreasing coefficient of the piston open area negatively affects milk dispersion degree. Using piston with the conical openings at its oscillation amplitude of 10 mm and vibrations frequency of 150 s-1 and emulsion acceleration of about 105 m/s2 it is possible to get milk emulsion with the average dispersion of the fat phase of 0.8 μm. Specific energy consumption here does not exceed 3400 J/kg. The received results prove high potential of further research- and-developments of the industrial prototype of the pulsation homogenizer.