Quench Zone

FIG. 23-3 Temperature and composition profiles, a) Oxidation of SOp with intercooling and two cold shots, (h) Phosgene from GO and Gfi, activated carbon in 2-in tubes, water cooled, (c) Gumene from benzene and propylene, phosphoric acid on < uartz, with four quench zones, 260°G. (d) Mild thermal cracking of a heavy oil in a tubular furnace, hack pressure of 250 psig and sever heat fluxes, Btu/(fr-h), T in °F. (e) Vertical ammonia svi,ithesizer at 300 atm, with five cold shots and an internal exchanger. (/) Vertical methanol svi,ithesizer at 300 atm, Gr O -ZnO catalyst, with six cold shots totaling 10 to 20 percent of the fresh feed. To convert psi to kPa, multiply by 6.895 atm to kPa, multiply by 101.3. 

Color reproduction of the chromatograms can be achieved by color photography — the best, but also the most expensive method of documenting thin-layer chromatograms. It can be used not only to produce true-color reproductions of colored zones but also — with the aid of a Reprostar (Fig. 64) or a UVIS analysis lamp (Fig. 6) — of fluorescent or fluorescence-quenched zones. When photograph-... 

Many other plate designs are now available with specific functionaHties, and because of modular conception, it is possible to perform aU the steps required in a chemical reaction in various zones such mixing zone, residence time zone, and quench zone. 

Schematic representation of a typical two-stage hydroconversion unit. The reactors contain multiple catalyst beds and quench zones. The second stage reactor is a recycle reactor.

C(v,P). It is seen that the temp of the spike N is somewhat lower than half of the C-J temp. Since the temp is low, it is not expected that the chem reactions could occur to any appreciable extent in the short time required for the gas to pass thru the initial shock. Actually the temp at Njis so low that in many practical cases one would expect a time lag or a quenching zone before the reaction sets in. Hirschfelder inferred that accdg to NDZ theory some chem reaction can take place within the detonation front (in cases of unusually high reaction rates), and blunt the von Neumann spike, as can be seen in Fig 4 (Ref 7, pp 172-74)... 

Zone 3 cool-down/quench zone—end product surrogate, C02, 02, 700°F... 

Ni-based steels, including Ni/Co alloys, showed much greater corrosion than the Pt alloys in zones other than the quench zone... 

The reaction kinetics of nitrogen fixation with hydrogen peroxide is defined by the quantity of fixed nitrogen. The primary fixation product is N20 which is uniquely formed in the reaction zone, whereas secondary products (H2N202, HN02, HN03) are, as shown below, formed in the quenching zone [44],... 

Temperature dependence of fixed nitrogen quantity ratio in gaseous and aqueous equation products on the quenching zone... 

Tests in the commercial boiler showed no significant differences in PNA emissions from EDS fuel oil and petroleum regular sulfur fuel oil. It is speculated that increasing the boiler size decreases the surface-to-volume ratio which provides a smaller quench zone for partially pyrolyzed combustion products. Emissions of PNA from the commercial scale combustion of coal-derived fuels may not be a problem. 

Figure 180 The range (Ze) of electrons (right ordinate) and the recombination probability [P ] for electrons (left ordinate). A comparison between the theoretical predictions according to Eqs. (153) and (328) (lines) and experiment (data points) shows good agreement for the electron mobility jie = 3.3 x 10-8 cm2/V s (a). Schematic cross-section of the EL device and monitoring of emission from two different emitters (PSu + TSA)—a blend of polysulfone (PSu) and tris(stilbene)amine(TSA), and PPV-poly(phenylenevinylene). Their thicknesses (dly d2) are subject to variation, d0 is the quenching zone of excitations by the Ca cathode (b). Adapted from Ref. 344.

Quantification. Fluorescence quenched zones of samples and standards scanned at 276 nm. 

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