Apparatus for zone

To complete Chapters 6 and 7 describing zone 1 equipment, this chapter is focused on electrical apparatus for zone 0 and zone 2 application, i.e. hazardous areas endangered by combustible gases, vapours or mist. The relevant standards and their technical content have been covered in Sections 2.3 for zone 0 and 2.4 for zone 2. 

For the purpose of visually inspecting the interior of a vessel, tank or barrel which is classified as zone 0, light generated by a zone 1 luminaire, which is located outside the vessel in zone 1, is brought into zone 0 via a fibre optics bundle. In the luminaire, the light is focused on the aperture of the fibre optics bundle by means of a condensor lens (Figs 11.1 and 11.2). 

Very different from these indirect ways into zone 0 is instrumentation for inductive conductivity or concentration measurement in a pipeline or 

Special requirements for construction, Teil 12-1/2000-02 test and marking of electrical apparatus of equipment Group II, category 1G 

Draft Standard pr IEC 60079-26/2002 Electrical apparatus for explosive gas atmospheres Part 26  

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Compared with pressurized apparatus for zone 1 application, some benefits are given for zone 2 application ... 

The other column is a special veraon of the Uniphor apparatus for zone electrophoresis, also produced and sold by the same company. Apart from this commercial equipment, there is yet another type described in the literature. This is designed for electrofocusing using a column density gradient (56). This apparatus is suitable for the separation and fractionation of proteins but less suitable for pi determinations. 

LKB-Produkter AB is reported to be planning the manufacture and sale of apparatus for zone convection electrofocusing. 

Figure 1 Apparatus for zone electrophoresis in inorganic ionic liquids. A and A, platinum wires for measurement of the electric field B and B working electrodes C and C electrolyte reservoirs (fused salt) D and D electrode compartments with sintered disks at the bottom and E glass plate that supports the electrophoretic medium, F. (Reproduced with permission from Alberti G, Allulli A, and Modugno G (1964) Journal of Chromatography 15 420-429.)...

Figure 2 Apparatus for zone-drawing and zone-annealing method.

The apparatus for moving boundary electrophoresis itself and the associated Schlieren optics are very costly. This is another restriction for the use of free electrophoresis. In comparison, the apparatus for zone electrophoresis is simple and cheaper. 

ISA S12.0.01 (lEC 79-0 MOD), Electrical Apparatus for Use in Class I, Zones 0 and 1 Elazardous (Classified) Locations General Requirements. Instrument Society of America, Research Triangle Park, N.C. 

Fig. 6. Side-arm tube of the apparatus for the determination of the coefficients of the heterogeneous recombination, y, of atomic gases previously dissociated in the rf discharge zone. The heterogeneous recombination proceeds on the inner glass walls of the horizontal side-arm tube and on a catalytically active cylindric sample of the metal investigated (Smith-Linnett method).

Instead of scraping and manual collection of the adsorbent, the band can be sucked off the plate with a Vacuum-cleaner -type apparatus. Dekker [50] described an apparatus for the isolation of compounds from layers by elution and direct Millipore filtration, and Platt [51] designed a zone collector that used vacuum to transfer separated zones from layers direcdy to vials for hquid scintillation counting of radioactivity. 

Figure 2. Schematic of apparatus for ZEKE-PFI spectroscopy, including magnetically shielded electron flight path and microchannel plate detector. Not to scale flight path is 50 cm long interaction zone is 1 cm long.

Figure 6.14. Scheme of the experimental apparatus for gravimetric measurements described by Zavrazhnov et al. (2003) in their investigation of the phase composition control in chemical transport reactions. (1) quartz ampoule, (2) thermocouples, (3) two-zone furnace, (4) quartz rods, (5) wire for suspending the ampoule, (6) support, (7) weighing beam of the analytical balance,... 

Figure 15.10. Simple apparatus for measuring metastable zone widths 36 ...

In the case of constant interfacial-area-stirred cells, although zone A is certainly an indication that the process is controlled by diffusional processes, the opposite is not true for zone B. In fact, in spite of the increased stirring rate, it may happen that the thickness of the diffusion films never decreases below a sufficiently low value to make diffusion so fast that it can be completely neglected relative to the rate of the chemical reactions. This effect, sometimes called slip effect, depends on the specific hydrodynamic conditions of the apparatus in which the extraction takes place and simulates a kinetic regime. 

Preparation of Macrocrystalline Iron(III) Oxide. Assemble an apparatus for preparing hydrogen chloride. To dry the gas well, install a column with phosphorus(V) oxide in addition to two wash bottles with sulphuric acid. Spill amorphous iron(III) oxide into the middle part of a three-section quartz tube (Fig. 136). Put the latter into a two-zone furnace. To retain the temperature difference, wrap the unheated zone (the middle of the tube) with asbestos. 

Fig. 22. Apparatus for the detection of organic free radicals. Methyl radicals are formed in the heated zone and react with the lead mirror downstream to form volatile tetramethyllead (199).

Fig. 9.20. Apparatus for the generation and sampling of anion radicals. The sample is added to the purged apparatus, S, is sealed off, and the appartus is evacuated. Chunks of sodium are melted through the capillary and then sublimed into the reaction tube. Solvent is distilled into the sidearm from the vacuum line, and the apparatus is tipped so that the resulting solution is poured onto the sodium mirror in the reaction zone. The resulting solution of radical is poured into Ihe S-mm HSR tube, frozen down, and sealed off at S2. The radical generation and collection can be carried out at reduced temperature by immersing the tube in an appropriate slush bath.

To increase the yield of triethoxysilane, it is necessary to eliminate the hydrogen chloride formed from the reaction zone as soon as possible. It is hardly conceivable in periodical bubble reactors with a small phase contact surface. Because it is difficult to bring large amounts of heat for HCI desorption to the reactive mixture, packed towers do not allow for a continuous process either. The most convenient apparatus for the etherification of trichlorosilane is film-type, which allows for a continuous process. 

Electrical apparatus for coal mines, type firedamp-proof, are constructed, built and tested according to the same philosophy as for zone 1 apparatus. Therefore, most of the IEC and European Standards describe constructional requirements and testing procedures for zone 1 apparatus and firedamp-proof apparatus in parallel. 

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