No abstract

No abstract

No abstract

AlSXRMPFIM/AP,T!%,~ X-ray analysis ard dilatonetry irdicate that both 3 C precipitation and a solutedreglike effect are associated with reacticn retaz&tim i n F d H b allay. %ere is no e v i h for molybdennn or carbcn/wlybdenm clustering in awtenite. INIIICDUCPIZHThe inhibiting effects of mlybdmm rn the t r a m f o m i c n of Fe++b alloys are d i a m m [1-6], but their origin d m mlear. What is clear is that l d of mlyb&mu of only a.few tenths of an atomic per cent significantly retard the rate of deccmposition of atstedte t o ferrite 4% carbids at a l l temperatures. This effect is particularly marked a t i n t e n d l a t e teapetahlres ( 50 C -703 C ) resulting in the deep lsys in the lllkwws of mny mlyWenrm steels. Similar effects are observed with other solute additions tut n b t o the sare degree a s with molylxbum. The molybdenum effect has been mriously attributed t o (1) Mo/ C clustering in the azsrenite pinning the interface [4], (2)solutedrag at the transPonnaticn ineerfaoe [3,6,7] a d (3)Merphsse interface precipitation [8,9]. There is no strong preferential evidence for any one of these hypotheses, * = Less than 2 s t a n d a r d d e v i a t i o n s .

in which the amounts of produced goods are rather small. To improve thermal and chemical resistance and widen the operational windows, Lapp Insulators Alumina GmbH and TU Dortmund, Equipment Design, have developed new concepts for small-scale plants with integrated key components made of ceramics. Here, the development of a smallscale extraction column [1] with ceramic components made of Al 2 O 3 , which are produced by 3D printing [2], shall be presented. The column and ceramic stirring elements are shown in the figure together with flow visualization in the stirring cell.The column with an active height of 220 mm was investigated with the EFCE test system n-butyl acetate/acetone/water for fluid dynamics and separation performance. The images in the right side of the figure show the droplet distribution in a single stirred cell with 900 min -1 and two different column loadings. Droplet size distribution was determined for different column loadings with mean diameters ranging from 0.55 to 0.7 mm. Mass transfer and separation efficiency is in the same range as the previously investigated column with metal internals [1] for direction disperse continuous d c and slightly lower for the opposite direction. Further investigations will focus on improved internals and other chemical systems.[1] A. Holbach et al., Chem. Eng. Process.