Temperature sensitivity of the gas

From Eq. (3.78), it can be seen that the temperature sensitivity depends on two par-ameters,[iil O and W O is the so-called temperature sensitivity of the gas phase , which is determined by the parameters of the gas phase, and W is the so-called temperature sensitivity of the condensed phase , which is determined by the parameters of the condensed phase. 

Fig. 7.22 Temperature sensitivities of the gas phase and the condensed phase of AP-HTPB composite propellants.

Substituting the and data into Eqs. (3.75) and (3.76), the temperature sensitivity of the gas phase, O, as defined in Eq. (3.79), and of the solid phase, as defined in Eq. (3.80), are determined as 0.0028 and 0.0110 respectively W is approximately four times greater than O. The computed Op represented by the sum of O and W is therefore 0.014 which is approximately equal to the Op derived from burning rate experiments. The heat of reaction at the burning surface is the dominant factor on the temperature sensitivity of the burning rate of the BAMO copolymer. 

Commercial Fischer-Tropsch processes have been based exclusively on gas-particle operations, mainly in fixed beds (P2). The chemical reactions are highly exothermic, however, and accurate temperature control is therefore difficult to achieve in a fixed bed. Good temperature control is important because of the temperature sensitivity of the chemical reactions taking place, and several attempts have therefore been made to develop processes based on other types of operation. 

For a perfect gas with P a pT, the temperature must therefore go up, which leads to instability, provided that the temperature sensitivity of the reaction rate is... 

The relationship between temperature sensitivity and burning rate is shown in Fig. 7.21 as a function of AP particle size and burning rate catalyst (BEFP).li31 The temperature sensitivity decreases when the burning rate is increased, either by the addition of fine AP particles or by the addition of BEFP. The results of the temperature sensitivity analysis shown in Fig. 7.22 indicate that the temperature sensitivity of the condensed phase, W, defined in Eq. (3.80), is higher than that of the gas phase, 5), defined in Eq. (3.79). In addition, 4> becomes very small when the propel-... 

As shown in Fig. 15.5, when a pyrolant of high pressure exponent is used, the variable flow range is increased. However, it is evident from Fig. 14.6 that the pressure exponent is required to be n < 1 for stable burning. It must also be noted that the temperature sensitivity of the pressure in the gas generator becomes high when a pyrolant of high pressure exponent is used. 

Experimentally measured pure-component adsorption characteristics of O2, N2, CO2, and SO2 on H-mordenite were correlated to predict the behavior of multicomponent mixture of these gases. These correlations, based upon the relationships developed by Myers and Prausnitz, were successfully substantiated experimentally. The CO2 and SO2, which are the predominantly adsorbed components, controlled the fate of the multi-component sorption. This prevailed even at the concentration levels where the pure-component data indicate comparable affinity for both the strongly and the weakly adsorbed species. Hence, indications are that adsorption may be effectively useful in exhaust gas cleanup processes. The temperature sensitivity of the pure components contributes significantly to the selectivity of the sieve for the various components, and the data obtained indicate that this also tends to favor the desired applications in pollution combat. 

The temperature sensitivity of gas phase 4> defined in Eq. (3.79) and the temperature sensitivity of the condensed phase V defined in Eq. (3.80) are obtained from the data of the burning surface temperature Ts, the temperature in the fizz zone Tg, the activation energy in the fizz zone Eg, the heat of reaction at the burning surface Qj, the temperature gradient in the fizz zone (f>, and the burning rate r. Figure 7-43 shows the temperature sensitivity of the burning rate of HMX-CMDB propellants as... 

Srivastava, R., Dwivedi, R., Srivastava, S.K (1998b). Effect of oxygen and hydrogen plasma treatment on the room temperature sensitivity of Sn02 gas sensors. Microelectronics Journal, Vol. 29, p>p. 833-838. 

Countercurrent flow of gas and sohds gives greater heat-transfer efficiency with a given inlet-gas temperature. But cocurrent flow can be used more frequently to diy heat-sensitive materials at higher inlet-gas temperatures because of the rapid coohng of the gas during initial evaporation of surface moisture. 

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