RESEARCH INTO USAGE EFFICIENCY OF THE PULSATION MACHINE WITH A VIBRATING ROTOR FOR MILK HOMOGENIZATION

The modification of rotor-pulsation machine – pulsation machine with a vibrating rotor (PM with VR) has been researched in the work. Rotor in such modification not only rotates but also oscillates axially with the frequency about 3000 min-1 and amplitude 0,5–1,0 mm. The aim of this research was to define specific features of milk homogenization process in PM with VR and disperse characteristics of milk emulsion.Analytical researches resulted in finding dependence of milk emulsion acceleration as a main factor of milk fat particles breakup subject to the design and kinematic parameters of PM with VR. Experimental researches were carried out on the laboratory setup of the pulsation machine with a vibrating rotor which was designed by the authors. The subject of experimental researches is cow's milk. The sizes of milk fat globules after homogenization were measured by the optical microscope equipped with a digital camera.The researches resulted in defining characteristics of milk emulsion dispersing in PM with VR. Thus acceleration grows when diameter, oscillation amplitude and rotation frequency of the rotor are increased, and channels length of the rotor and stator, the gap between them are decreased and the number of rotor openings is 4 or less.Empirical dependence between the average diameter of the fat globule (0,7–1,9 μm) and the average emulsion acceleration ((1–10)·103 m/s2) in the interrupter of PM with VR is defined which proves that the emulsion flow acceleration is the main cause of homogenization of PM with VR with 92 % confidence. High quality of the milk emulsion after processing in PM with VR has been proved. The crankshaft rotation frequencies up to 2880 rpm and rotor oscillation amplitude of 1 mm enable to receive milk emulsion with the average dispersion about 0,8 μm that corroborates using PM with VR in the industrial conditions for milk homogenization to be perspective

Дослідження гомогенізації молока в пульсаційному апараті з ротором, що вібрує

In the modern dairy production schemes one of the main problems is high energy consumption in the process of homogenization. One of the perspective ways to solve this problem is to research and develop the variety of rotor-pulsation machine – pulsation machine with a vibrating rotor. Homogenization in such machine allows getting high values of emulsion flow acceleration and using the resonance phenomenon that has a positive impact on quality and energy consumption of the machine.As a result of analytical researches, the hypothesis is suggested about the key role of emulsion acceleration in the process of milk emulsion fat phase dispersing in the pulsation machine with a vibrating rotor. We received dependences that associate instantaneous and average acceleration of the emulsion with the frequencies of rotation and vibration of the rotor, its diameter and amount of openings. These dependences allow determining conditions for increasing degree of emulsion dispersing. The experimental researches resulted in defining interconnection between acceleration of emulsion and dispersion of fat phase of milk, which confirms the hypothesis about the mechanism of homogenization in the pulsation machine with a vibrating rotor. The middle sizes of fat globules of milk are found to be dependent on the frequency of rotation and amplitude of rotor vibration. With the frequencies of rotation of the crank shaft up to 2880 rpm and amplitude of rotor oscillation 1 mm it is possible to get milk emulsion with the average size of around 0.8 μm. The results of the research prove the use of such machines in the technological processing lines of milk to be promising. The investigated machine allows receiving highly dispersed emulsion that is on the same level as processed in valve homogenizers with considerable decrease in energy consumption.Обосновано влияние основных кинематических и конструктивных параметров пульсационного гомогенизатора с вибрирующим ротором на среднее ускорение эмульсии в отверстиях прерывателя. Установлена зависимость средних размеров жировых шариков молока от ускорения эмульсии в прерывателе аппарата и частоты вращения и амплитуды вибрации ротора. Определенные дисперсные характеристики молока после гомогенизацииОбґрунтовано вплив основних кінематичних і конструктивних параметрів пульсаційного гомогенізатора з ротором, що вібрує, на середнє прискорення емульсії в отворах переривника. Встановлено залежність середніх розмірів жирових кульок молока від прискорення емульсії в переривнику апарата та частоти обертання й амплітуди вібрації ротора. Визначені дисперсні характеристики молока після гомогенізаці