The causes of milk deposit formation on the walls of the heat exchangers during the heat treatment of milk

Abstract

Ovim radom opisani su rezultati istraživanja u otkrivanju uzroka i sprječavanju nastajanja mliječnog taloga. Toplinskom obradom mlijeka dolazi do nepoželjne pojave, nastajanja mliječnog taloga na ogrjevnoj površini izmjenjivača topline. Ova pojava uzrokuje smanjenje koeficijenta prijenosa topline i pad tlaka, blokira put mlijeku, stvara dodatne troškove u proizvodnji i povećava proizvodne gubitke. Nastajanje mliječnog taloga rezultat je složenih procesa uzrokovanih zagrijavanjem proteina i mineralnih tvari mlijeka. Nastajanje mliječnog taloga uzrokuje: pH-vrijednost, količina proteina i mineralnih tvari mlijeka, plinovi otopljeni u mlijeku, karakteristika ogrjevne površine, razlika temperature mlijeko - ogrjevna površina i režim strujanja mlijeka. Na kemijski sastav mlijeka ne možemo utjecati u većoj mjeri, ali zato možemo utjecati na parametre procesa toplinske obrade kako bi minimalizirali ovu pojavu, a to i je predmet novijih istraživanja.The results of research on finding the causes and preventing the formation of milk deposit are described in this paper. During the heat treatment of milk, an unwanted phenomenon occurs; the formation of milk deposit on heating surfaces of heat exchangers. This phenomenon causes the decrease of heat transfer coefficient as well as the pressure drop, it restricts the flow of milk, and causes additional production costs and increases production loss. The formation of milk deposit is a result of complex processes caused by thermal treatment of proteins and mineral substances in milk. Factors which cause milk deposit are: pH-value, the amount of proteins and mineral substances in milk, dissolved gases in milk, characteristics of heating surface, the difference in temperatures of milk and heating surfaces, and the regime of milk circulation. The chemical composition of milk can not be influenced, but the standards of heat treatment in order to minimise this phenomenon can, and that is precisely the topic of the latest researches