Інтенсифікація процесу ультрафільтрації знежиреного молока

Abstract

Розглянуто питання про використання м ембранних процесів під час обробки знежиреного м олока ультрафільтрацією. Подано аналіз результатів теоретичних та експерим ентальних досліджень стосовно визначення технологічних характеристик ультрафільтраційних м ембран під час ультрафільтрації знежиреного молока.

The paper presents a new methods of processing the findings on the ultrafiltration concentration of skimmed raw milk with the use of a new method to prevent a polarization layer on the membrane. Food liquids were treated by ultrafiltration with flat membrane module elements (the membranes proper). The process was carried out in dead end mode with using, as the method of intensification – perforated vibrating disc and bubbling device. The paper reveals the research findings on the bubbling method effect on a polarization layer in the membrane processing of skimmed milk and on the performance of ultrafiltration membranes. The devised mathematical models are based on the regression equations of the factorial experiment on the selection of technological parameters of the UF-concentration of skimmed milk with the use of the feedstock bubbling over the membrane surface. We have determined the rational working parameters of the process; these working parameters are as follows: the working pressure is 0.4…0.5 MPa, the skimmed milk temperature – 40-50 C, the skimmed milk bubbling frequency – 0.10-0.15 min-1 , and the bubbling pressure – 0.56-0.58 MPa. Analytical and experimental studies that were taken show the technological limits of the modes of regulation of receiving concentrate in ultrafiltration concentration process of food liquids. It is experimentally proved that the bubbling method that has the advantage of preventing the formation of a polarization layer improves the efficiency of the UF-separation of skimmed milk. It is found that in the bubbling mode, the UFconcentration of skimmed milk is 1.3-1.4 times more intensive in comparison with UF in the dead-end mode. Research on the PAN-types of UF-membranes in the UF-concentration of skimmed milk shows that the proposed method of controlling the polarization layer on the membrane can improve the latter’s performance due to a thinner layer of the accumulated macromolecular substances thereon and an enhanced working surface of the membrane.