Reactor start

The highest power of a reactor of the HTGR type was 330 MWe in Fort St. Vrain, Colorado. The reactor, started in 1979, had many technical problems, including helium leaks, and did not perform up to expectations. It was shut down in 1989. 

The Los Alamos water boiler served as a prototype for the first university training reactor, started in September 1953 at North Carolina State College. The cylindrical reactor core used uranyl sulfate [1314-64-3] UO2SO4, and cooling water tubes wound inside the stainless steel container. A thick graphite reflector surrounded the core. 

Fed-batch mixed reactor starting with a relatively dilute solution of substrate this provides control over the substrate concentration. High rates are avoided. Fed batch is used for baker s yeast to overcome catabolite repression and to control oxygen demand. It is also used routinely for production of Penicillin. 

Steady state analysis explicitly evaluates model parameters, Dynamic simulations predict reactor start-up transients. 

N umerical simulations of reactor start-up were programmed, predicting monomer and initiator concentrations, total polymer concentration, weight and number average molecular weights, viscosity and population density distribution dynamics. The following two relationships obtained from steady state observations were utilized in the simulation. 

Reactor start-up simulations require initial values of A., T(n,t) and T. be zero. Monomer... 

Dynamic simulations for an isothermal, continuous, well-mixed tank reactor start-up were compared to experimental moments of the polymer distribution, reactant concentrations, population density distributions and media viscosity. The model devloped from steady-state data correlates with experimental, transient observations. Initially the reactor was void of initiator and polymer. 

Assume laminar flow and a parabolic velocity distribution. Calculate the temperature and composition profiles in the reactor. Start with 7=4 and double until your computer cries for mercy. Consider two cases (a) 7 = 0.01 m (b) 7 = 0.20 m. 

In Fig. 5(b), the reactor started with pH control and stopped pH control after 100 days. Then PAOs concentration increased significantly after stopping pH control and GAOs concentration decreased. 

Rhodium and platinum metals can be more conveniently vaporized with electron-beam vaporization source, in a stainless steel reactor, starting from metal powders deposited into a graphite crucible. 

The design of a reactor starts with the expression of material balance for any reactant (or product). The basis for all material balances is the law of conservation of matter, which states that matter cannot be created or destroyed in a given system (nuclear reactions are, of course, out of this dictum). Material balance is generally given as ... 

It was also established that the distribution of the liquid phase in the reactor depends on the reactor start-up procedure. When the flow rate of liquid AMS is reduced from 1.47 x 10 1 g s 1 (Figure 5.4.6, images 43 and 45) down to 2.96 x 10-2 g s 1 (images 85 and 87), the distribution of the liquid phase hardly changes and the catalyst bed contains a substantial amount of liquid. At the same time, if... 

For a single continuous reactor, the model predicted the expected oscillatory behaviour. The oscillations disappeared when a seeded feed stream was used. Figure 5c shows a single CSTR behaviour when different start-up conditions are applied. The solid line corresponds to the reactor starting up full of water. The expected overshoot, when the reactor starts full of the emulsion recipe, is correctly predicted by the model and furthermore the model numerical predictions (conversion — 25%, diameter - 1500 A) are in a reasonable range. 

At this temperature the reaction rate constant is equal to 0.082 liters/mole-min. If the reaction takes place in a constant pressure reactor, starting with pure gaseous alcohol at a pressure of 2 atm, find the time necessary to reach 20% decomposition ... 

A rate equation is required for this reaction taking place in dilute solution. It is expected that reaction will be pseudo first-order in the forward direction and second-order in reverse. The reaction is studied in a laboratory batch reactor starting with a solution of methyl acetate and with no products present. In one test, the initial concentration of methyl acetate was 0.05 kmol/m3 and the fraction hydrolysed at various times subsequently was ... 

A first order reversible reaction, A B, is carried out in a plug flow reactor, starting with pure A. The specific rate and equilibrium constants are functions of temperature, k = A exp (-E/T)... 

Suppose a constant 362,000 Btu/h of heat is transferred into the jacket from the reactor, starting at time equal zero when the jacket is at 145 T. How long will it take the jacket water to reach 99 F if the cold water addition rate is constant at 416 pounds per minute ... 

The reactor start-up was performed by feeding a water-free mixture of methane and air with an O2/CH4 molar ratio of 1.36 and by inducing for few seconds the voltaic arc between the spark plugs. When the mixture is ignited, the temperature on the SiC foam suddenly (1 min) reaches around 1000 °C. Furthermore, due to the heat transfer, the temperature in the catalytic zone reaches in about 2 min the light-off value with full reactants conversion. The whole start-up phase is no longer than 3 min. 

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. 

In an alternative process, the starting material consists of needle-shaped particles of a-Fe203 instead of FeOOH pigments [5.9], [5.10]. The synthesis is carried out in a hydrothermal reactor, starting from a suspension of Fe(OH)3, and crystal growth is controlled by means of organic modifiers. 

Figure 6.10 Example substitution reaction in the Isoperibolic batch reactor starting from 25°C with a constant cooling system temperature (Tc) at 25 °C. Reactor temperature (T,°C) and conversion as a function of time (h).

In Figure 4.26 a temperature profile has been specified. The reactor starts at 300 K at time equal zero, and the temperature is ramped to 400 K at 10 min. Then it is ramped to 430 K at 20 min and remains at this temperature for the rest of the 120-min batch. Figure 4.27 shows that the Reactions page tab permits the installation of reactions in the normal way, as discussed in Chapter 2. The primary reaction is ethylene and benzene forming ethylbenzene. 

Let us consider the increase in recycle flow. The higher flow initially decreases temperatures in the reactor. Pressure begins to build. Then the temperatures in the reactor start to increase because of the reaction rate increase due to higher pressure. At about 7 min the exit temperature increases to a value slightly above its steady-state level. The higher exit temperature increases the reactor inlet temperature through the FEHE, and this starts a temperature wave that moves down the reactor. Temperature Tt2, which is located at about 40% of the way down the reactor, spikes first. Then... 

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