Wall cooling screen

The basin A is then gently heated by a small Bunsen flame, which should be carefully protected from side draughts by screens, so that the material in A receives a steady uniform supply of heat. The material vaporises, and the vapour passes up through the holes into the cold funnel C. Here it cools and condenses as fine crystals on the upper surface of the paper B and on the walls of C. When almost the whole of the material in A has vaporised, the heating is stopped and the pure sublimed material collected. In using such an apparatus, it is clearly necessary to adjust the supply of heat so that the crude material in A is being steadily vaporised, while the funnel C does not become more than luke warm. 

In an atmosphere of carbon dioxide, filings from the reguli were screened through a 200-mesh sieve and collected in thin-walled glass capillaries about mm. in diameter. The capillaries were then evacuated and sealed, and the specimens were annealed at 280° C. for 40 hr. and allowed to cool at the rate of about 0-001 ° C./ sec. (It was observed that specimens which were not annealed gave diffuse diffraction lines the lines were made sharp by the process of annealing as described above.)... 

In the process, chlorine is fed in below the surface of the aluminum, and the product sublimes and is collected by condensing. These air-cooled condensers are thin-walled, vertical steel cylinders with conical bottoms. Aluminum chloride crystals form on the condenser walls and are periodically removed, crushed, screened, and packaged in steel containers. 

Planetary coolers Acoustic screening wall with ventilation openings or fixed enclosure with ventilating fans, or movable enclosure around noisiest part of the cooler, provided (if necessary) with cooling fans if no water spraying system for cooling the tubes is installed. A more radical solution is to accommodate the whole kiln and planetary cooler in a closed sound-insulated building with air intake fans and with exhaust air outlets provided with sound attenuators (silencers) (see Funke, 1973). 

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