摘要
综述了工业化刮壁式搅拌器的型式、刮板形状、刮板材质及其流型、搅拌功耗和刮膜给热系数,并探讨了刮壁机构强化高粘流体传热的机理。
Heat transfer enhancement for highly viscous fluids in solution polymerization for synthetic rubber is an important engineering problem which can be solved effectively by using scraped-surface apparatus .This paper presents a review of literatures pertaining to power consumption and scraped-film heat transfer coefficient for scraped-surface liquid processing equipment . Various types of industrialized scraped-surface agitators , the shape and material of the scraping blades and flow patterns are outlined . The mechanism of heat transfer enhancement for highly viscous liquids by using scraped-surface apparatus is discussed .The industrialized scraped-surface heat exchanger can be chiefly represented by the C & R Reactor and the Votator . The most commonly used materials for scraping blades are polytetrafluoroethylene , aluminium , copper , phenol formaldehyde bonded fabric laminate , knit mesh , et al . Spring-loaded , hinged and floated types are three main methods to fix scraping blades to agitator .Researches have been carried out on heat transfer in scraped-surface agitated vessels and pipes . Mostresearchers used the penetration theory model based on the transient heat conduction into a semi - infinite solid as the heat transfer mechanism which led to the following expression for heat transfer coefficient : hg= 1.128 (ρCpKnBN)0.5Researchers also made different corrections to the above theoretical correlation .In the meantime ,they presented many empirical correlations for heat transfer coefficient .The author of this paper indicates that in heat exchangers such as the Votator , fluids exert only a rotary movement due to scraping effects ; while in agitated vessels with helical ribbon agitator and scraping blades , fluids exert an axial movement due to the agitation of helical ribbon besides the rotary movement .Therefore it can be expected that the heat transfer coefficient for agitated vessels with helical ribbon agitators and scraping blades may be higher than that of the Votator .
出处
《合成橡胶工业》
CAS
CSCD
北大核心
1992年第2期120-124,共5页
China Synthetic Rubber Industry
关键词
传热
刮壁
搅拌器
合成橡胶
heat transfer
scraped - surface agitator
stirring power consumption
scraping blade
highly viscous fluid
review
