Gases, temperature profiles

Fig. 7. Effect of inlet gas velocity on steady-state gas temperature profile, type I conditions.

Figure 26 shows the predicted axial gas temperature profiles during reactor start-up for standard type I conditions with varying numbers of axial collocation points. Eight or more axial collocation points provide similar results, and even simulations with six collocation points show minimal inaccuracy. However, reducing the number of collocation points below this leads to major discrepancies in the axial profiles. 

Fig. 26. Axial gas temperature profiles as a function of the level of axial discretization, type I conditions.

Figure 7. Radial process-gas temperature profiles at several bed depths. Key -------, averaged radial Tt and , TS as predicted by one dimensional model.

Figure 7.13 Calculated and measured radial gas temperature profiles in a wall-dominated laser discharge operating at 10.5 Torr [69].

B) Gas temperature profile through the converter. C) Ammonia concentration versus temperature (if. Fig. 82)... 

Figure 104. Block diagram and gas temperature profile for a steam reforming ammonia plant...

The measured values of NO, and CO at the exit are plotted in Figure 5 vs. residence time at high temperature. These values of residence time were computed from the gas temperature profile down the tube, which was estimated from the wall temperature profile. The NO, decreases, and the CO increases with decreasing residence time as might be expected from kinetic considerations. These very low values of NO, and moderate values of CO are comparable in magnitude and trend with those of Bem-... 

Kim, H. K., and Song, T.-H. "Determination of the Gas Temperature Profile in a Large-Scale Furnace Using a Fast/Efficient Inversion Scheme for the SRS Technique." Journal of Quantitative Spectroscopy Radiative Transfer 93 (2005) 369-81. 

The gas temperature profiles used for this analysis were calculated from the assumption of equilibrium in the reaction... 

Such a situation can be dealt with in two ways. The first way is to analyze the data as such. The temperature dependence of the rate parameters is then directly included into the continuity equation and the resulting equation is numerically integrated along the tube with estimates for the parameters. If the gas temperature profile itself is not available or insufiBciently defined, the energy equation has to be coupled to the continuity equation. To determine both the form of the rate equation and the temperature dependence of the parameters directly from nonisothermal data would require excessive computations. 

Figure I Gas temperature profiles in the l-butene dehydrogenation reactor.

Since the gas-to-wall heat transfer is strongly affected by the pressurizing-gas temperature gradient, a gas-temperature profile was assumed. This profile is defined as a linear gradient bounded by the inlet-gas temperature Ti and a temperature T that is a function of the mixed-gas temperature. ... 

T is a fictitious boundary to the assumed gas temperature profile. Since one of the profile boundary temperatures and the mean temperature are defined, the remaining profile boundary temperature, TT, is fixed but lot necessarily equal to the gas inlet temperature or saturation temperature. 

Pg gas temperature at some point y of assumed gas-temperature profile, °R Ti = inlet-gas temperature, °R... 

Tj = boundary of assumed gas-temperature profile, °R Tsl = saturated-liquid temperature, °R = saturated-vapor temperature, R V = tank ullage volume, ft ... 

Figures 7 and 8 show a comparison of the gas temperature profile between the baseline case and OENR (top view and front view). The oxygen jets quickly mix with the surrounding gas...

Figure 7 Gas temperature profile compaiison base case (top) and OENR (bottom)...

Figure 8. Gas temperature profile in the O2 injection cross-section (base case on top, OENR on...

The TBP-GLC s on the liquids are for calculation of yields of various boiling range liquid products. The C/H/S analyses are used for elemental material balance, calculation of heats of reactions and calculation of hydrogen distribution, i.e., hydrogen content of liquid product. From the material balance and the product analyses, a final yield report is made as shown in Table II. With each yield report, the operating conditions are reported which include tube identification, hydrocarbon and water feed rates and pressure and bulk gas temperature profiles. 

The capacity of Coil 2 is 4.3 times that of Coil 1. The gas temperature profiles of Coils 1 and 2 are shown in Figure 4. While the axial temperature profile in Coil 1 is approximately linear, the temperature profile of the SRT 111 coil is approximately hyperbolic. 

Figure 2. Gas temperature profiles along the reactor when inter-stage injection is applied and in standard operation (St = 20, Da = 0.0496, o) = 0.1, fi = 1, i%o=2, i o= 7, G2=W%G,).

Process gas temperature profiles in various types of reactors. From Plehiers and Froment [1987]. 

Fig. 190. Near-wall gas temperature profile for silica-lined graphite furnace at 1500 0 dial.

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