Double packs

Fig. 24.7. Schematic of acid heat to steam energy recovery system, after Puricelli et al., 1998. It is for intermediate H2S04 making, Fig. 9.6. Note (i) the double packed bed H2S04 making tower and (ii) boiler. Industrial acid heat recovery H2S04 making towers are 25m high and 10 m diameter. They produce 2000 to 4000 tonnes of H2S04 per day. For photographs see Sulfur, 2004.--------- large flows. small flows.

A second key feature of Fig. 24.7 s version of the process is its double packed bed H2S04 making tower - through which ... 

Double packs are one, often discussed, concept which helps to balance loads between the user s back and front (Johnson et al., 1995). Double packs can limit a user s field of view and awareness of foot placement, increase thermal load (they cover more of the torso), and may cause more discomfort at the shoulders and neck. There may be benefits from the use of waistcoat-type LCS, as a form of double pack concept, if the above issues can be mitigated. 

The analysis of NO and NO2 was effected by a continuous chemiluminescence apparatus (Beckmann model 955), NH3 was detected by a continuous IR spectrophotometer (Hartmann Braun model Uras 30y N2 and N2O concentrations were measured by gaschromatographic analysis on a double packed 5A molecular sieves-Porapak Q by a Hewlett Packard instrument (model 5890) with a TCD detector. 

Fig. 2.32 The FM21 SP Electrolyser. (a) The overall construction, (b) A single electrode, which has a nominal projected area of 0.21 on each face. The photograph shows the electrolyte ports and the current feeder busbar. A symmetrical lantern blade electrode is shown complete with its compression-moulded gasket, (c) An assembled, multi-electrode reactor, showing the electrolyte manifolds and the end plate. The electrolyser unit is capable of taking up to 60 electrode pairs, which would provide a projected cathode or anode area of up to 25 m. A double-pack version utilizes a central plate extending, the capacity to a maximum of 120 electrodes (50 m ). The construction of FM21 electrolysers for chloralkali production is considered in Chapter 3. (Photographs supplied by ICI Chemicals and Polymers Ltd.)...

Provision should be made to collect coolant vented and drained from the RCSASs. Leaks can occur from, among others, double packed valve stems, valve seats, pump seals and intergasket cavities during reactor operation. 

A.27. The heavy water collection system should be designed to cohect leaks from any anticipated leak source in the RCS, such as double packed valve stems, pump seals and intergasket cavities. The system should also be used to cohect venting and draining fluids from the RCSASs and from equipment of other systems. 

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