Wire wrapped thick-walled

The single-tube heat transfer test unit (Figs. 1 and 2), was essentially a hollow, thick-walled, electrolytic copper cylinder 6 in. long with a 0.25 in. ID and a 0.75 in. OD. The outer surface was threaded with 3/4-10 threads. Thin-walled stainless steel tubes were brazed to the inlet and outlet to minimize heat conduction losses. The outer surface of the unit was coated with a 1/32 in. layer of Allens PBX ceramic cement and a bare 20 gauge constantan wire heating element was wrapped tightly in the thread grooves after the cement had dried. 

Very pure uranium Is obtained by electrolysis of KUFg In an NaCl-CaClg melt. A cylindrical graphite crucible serves both as the electrolysis vessel and the anode. It has an l.D. of 6 cm., a height of 15 cm. and walls 1-2 cm. thick. The electrical connection is made with a strip of Ni sheet wrapped around the upper part of the outside wall. The cathode is a strip of Mo sheet, 0.5 mm. thick and 1 cm. wide, which is immersed in the melt so that its lower end is 2.5 cm. above the bottom of the crucible. The latter stands in a suitable refractory vessel, around which a heating wire is wound. The entire apparatus is placed in a large-diameter lead vessel filled with thermal insulation. 

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