Water cooling sources

Figure 1.5 Heat transfer strategies in multitubular packed-bed reactors, (a) Cross-flow, (b) parallel flow, and (c) boiling-water cooling. (Source Eigenberger [4]. Reproduced with permission of John Wiley Sons. Inc.)...

Source. This usually consists of a filament or rod of some refractory material, heated to a temperature of around 1500 K so as to emit infrared radiation. The Globar is probably the most common source of mid-infrared radiation, consisting of synthetic silicon carbide. This usually has to be water-cooled, however. Filament (Nernst), and nichrome wires are also popular—and may not require water cooling. Water-cooled sources should deliver a higher and more stable output, which is better suited to quantitative applications. 

The advantages of air-cooled sources are that they are rugged, simple, and cheap. The only potential drawback to air-cooled sources is that in a few very demanding applications they are not intense enough. In these cases water-cooled sources are used. However, for the vast majority of samples and applications, air-cooled sources provide enough intensity to give spectra of high SNR. 

Figure 1.8 Evaporation of a metal by laser beam irradiation to provide a source for the deposition of nanoparticles on a water-cooled substrate...

Cooling towers and evaporative condensers release into the atmosphere fine droplets of water, which may carry sources of contamination such as algae and bacteria. Many of these thrive at the temperatures to be expected in water cooling systems and one of them, Legionella pneumophila, has been identified as a particular hazard to health. Cooling apparatus should be cleaned and disinfected frequently to reduce these risks of contamination and should not be located where water droplets can be drawn into ventilation air intakes. 

The heat reclaim packaged unit system comprises water-cooled room units with reverse cycle valves in the refrigeration circuits. The water circuit is maintained at 21-26°C, and may be used as a heat source or sink, depending on whether the individual unit is heating or cooling. (See Figure 28.11.)... 

Three types of light sources for artificial weathering are in common use (1) enclosed UV carbon arc [7.5 UV energy output, approx. (x sunlight)], (2) open-flame sunshine carbon, and (3) water-cooled xenon arc. Selection of the light source involves many conditions and circumstances, such as the type of material being tested, product service conditions, previous testing experience, or the type of information desired. 

Fig. 5.12. DIP of a JEOL JMS-700 sector instrament for use with El, chemical ionization (Cl) and field ionization (FI). The copper probe tip holds the glass sample vial and is fitted to a temperature-controlled heater (left). The heater, a thermocouple, and circulation water cooling are provided inside. The (white) ceramics insulator protects the operator from the high voltage of the ion source.

Wastewater sources in this subcategory are the leaching process, makeup water, cooling water, and stripping water. Toxic pollutants are present at insignificant levels in the wastewater discharges. 

---