Ceramic sleeve

The development of in situ electrolytic methods by Allied Chemical resulted in a novel unit, the electropulse column, in which mass transfer and electrolytic reduction are carried out simultaneously (25). The basic feature of the electropulse column, (Fig. 3), is the dual function of the horizontal perforated plates, acting as cathodes as well as pulse plates, and the introduction of vertical anode screens contained in porous ceramic sleeves. This design was found particularly suitable for Pu-U partitioning, since it permits operation with an aqueous-continuous phase, which is needed to maintain adequate electrical conductivity, while the organic to aqueous flow ratio is kept quite large to obtain a high plutonium concentration in the exiting aqueous stream. 

Figure 5.21. Commercial DTA sample holders evaluated by Dollimore et at. (139). ( ) Netzsch standard cell (nickel block, wells approx. 8 mm in diameter) (/>) Stanton Redcroft cell (aluminum pans, approx. 6 mm in diameter) (e) Netzsch catalytic cell (ceramic sleeves, approx. 8 mm in diameter) (d) Du Pont intermediate temperature cell (sample tube approx. I mm in diameter) (e) Wilburn cell (nickel block, wells approx. 9 mm in diameter) f) Du Pont high-temperature cell with platinum liners in place (sample holder approx. 5 mm in diameter) Arrows indicate normal direction of gas flow.

From the support ring to the lower brick lining, the quench was refined with four layers of chopped strand mat and two C-veil layers. Finally, a ceramic sleeve was fitted within the quench s 950 mm inner diameter, completing repairs. 

Although coatings have been successfully used on the shaft, improvements may be possible in light of the work discussed in Section f>, by replacing the HPSN with silicon carbide and employing a silicon carbide sleeve on the shaft. However the technical difficulties of fitting ceramic sleeves to shafts are well known and such problems have not been definitively resolved. 

Ceramic plug Quartz fiber Annular ceramic Sleeve... 

Ceramic Endcover Ceramic Rotor s. Ceramic Sleeve ... 

Radiation error may be largely eliminated through the proper use of thermal shielding. This consists in placing barriers to thermal radiation around the probe, which prevent the probe from seeing the radiant source or sink, as the case may be. For low-temperatiue work, such shields may simply be made of sheet metal appropriately formed to provide the necessaiy protection. At hi er temperatures, metal or ceramic sleeves or tubes may be employed. In apphcations in which gas temperatures are desired, care must be exercised so as not to cause stagnation of flow aroxmd the probe. 

Nylon and poly(vinyl chloride) sleevings ate used for preinsulated terminals. Ceramics (qv) ate employed in some high voltage power connectors. Hard mbbet shells insulate connectors that serve underground power distribution cables. 

The sample holders in (fc)-(m) are used in Linseis DTA equipment. In (k), removable sleeves made of metal or ceramic are used to contain the sample. This type of sample holder is convenient for cleaning purposes as the sleeve may be easily removed, leaving the exposed sample. A disadvantage of this type of sample holder is that the thermocouple is in direct contact with the sample and may be attacked by corrosive sample materials, thus changing its EMF output characteristics. A similar disadvantage is present for the probe-type sample holders in (/) and C/i). in which the thermocouple is immersed in the interior of the sample. The glass sample container in tei is usually a disposable capillary tube I -2 mm in diameter. A sample holder for horizontal use is illustrated in Iml. 

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