Furnace photograph

Processing equipment — belt furnace. (Photograph courtesy of DuPont and Co.)... 

Hall and Diederichsen (22) projected a stream of droplets (diameters 150 to 170 microns) from the periphery of a spinning disk up into a vertical furnace maintained at a sufficiently high temperature for ignition, 710° C. The spinning disk atomizer employed was capable of producing droplets of uniform, predetermined size. Drum photographic records were obtained of the luminous portion of the droplet trajectory and drop burning times were estimated therefrom. 

Bolt, Boyle, and Mirsky (2E) discuss and evaluate different techniques of producing droplets. Their work includes photographing drops falling through a vertical furnace. They have successfully suspended drops in a vertical wind tunnel, using a stationary ultrasonic field to center the drop. 

A large portion of the literature discusses the use of suspended drops on fine filaments. This technique has been used with visual and photographic observation (5E, 6Ef 8E, 9E, llEt 16E). Results show the mass rate of change of size due to evaporation to be proportional to the first power of the diameter. Kobayasi (HE, 15E) first suspends the droplet on a silica filament and then moves a heated furnace to surround the droplet. Nishiwaki (19E) uses a similar experimental device. Instead of a filament to support the drop, Wakil, Uyehara, and Myers (25E) use a fine thermocouple. 

Figure 2 is a photograph of a large, complex plant. Plants such as this contain reactor furnaces, distillation towers, heat exchangers, separators, dryers, compressors, and various other units as required by the specific feedstock and product distribution achieved. Figure 3 shows a simplified diagram of a plant. 

Fig. 3.0. View of spinning cup sulfur burner from inside sulfur burning furnace - burning capacity 870 tonnes of molten sulfur per day. The thermocouple at top and central blue sulfur-rich flame are notable. Photograph courtesy of Outokumpu OYJ. www.outokumpu.com...

Sessile drop method is the most frequently used method (c.f. Section 6.2.4.1.). In the measurement at high temperatures the drop of the melt is lying on the solid base placed in a horizontal furnace tube. The contact angle is measured on photographs of the drop. 

Multitube furnaces (14 to 18 tubes arranged in two rows) are frequently in use today. A photograph of an industrial aggregate is shown in Fig. 5.26. The boat material, in most cases, is an iron alloy high in Ni and Cr (Inconel). More seldom, because of the high price, boats are made of TZM (molybdenum alloy with Ti, Zr, and C) or pure tungsten. 

Fig. 5.1 Schematic diagram of the cell for extracting lead and zinc from electric arc furnace (EAF) dust together with a photograph of the pilot plant built for 5-kg dust extraction batches (Reproduced from Ref [19], with kind permission of The Royal Society of Chemistry)...

A beam of sodium atoms (of unknown spin), from a furnace (left), passes between the poles of a specially designed electromagnet (centre). When the magnet is switched off, the beam produces one dark spot on the photographic plate (right) but when it is on the beam is split into two components, up-spin and down-spin (represented by the arrows). 

Fig. 9.3 Photographs of simple atmospheric muffle furnaces (courtesy Gasbarre, Sinterite Furnace Div., St. Marys, PA, USA).

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