Staggered reactors

Temperature explicit functions for inactivation parameters considering substrate and product modulation and a two-stage series mechanism were also determined and validated as already presented in Table 5.2. Temperature optimization of CPBR was then accomplished by replacing these temperature-explicit functions in Eqs. 5.76 and 5.79. A battery of staggered reactors was considered to absorb output flow fluctuations due to enzyme inactivation (see Eqs. 5.82 and 5.83). Elow-rate was considered constant during each time interval (see Eq. 5.84) so that variation in substrate conversion was below 1%. Conditions of operation and design parameters used in the simulation of an industrial CPBR for the hydrolysis of whey permeate with immobilized p-galactosidase are summarized in Table 5.4. 

An alternative method to account for bed dispersion is to model the bed as a cascade of well stirred tank reactors, each with a uniform temperature and concentration (124,1 5) Transverse dispersion can be accounted for by staggering the cells so that each cell feeds into two different cells in the forward direction (126). When the value of L/d is large, say above 20, the two models are not very different if the number of cells in the cascade is chosen to equal N = PeL/2d. When Pe = 2, this amounts to considering... 

Perforated plate distributors are widely used in industry because they are cheap and relatively easy to manufacture. Simple perforated plate-type distributors suffer from particles passing back through to the plenum despite mean gas velocities well above the settling velocity for the particles. This is because of imbalances in gas flow between the orifices, which is difficult to eliminate. Hence, such plates take the form of either a layer of mesh sandwiched between two perforated plates or two staggered perforated plates without a mesh screen (Kunii and Levenspiel, 1991). However, these structures often lack rigidity and need to be reinforced or sometimes curved (concave to the bed) to withstand heavy loads. The diameter of the orifices in a perforated plate distributor varies from 1 or 2mm in small beds used for research or very small-scale production to 50 mm in very large chemical reactors. Most food applications are likely to use apertures of intermediate size. 

We have evaluated and developed new process modifications using the model. The concept of staggering the reactor inlet temperatures to equalize the aging rates in all three reactors (15) was evaluated with the model. Model simulations, to quantify the benefits of this modification, could be carried out in a day. Corresponding experiments showing similar effects would have required months to complete. With minimal modifications to the model, the benefits for splitting the reformer feed among the three reactors (16) were also determined. 

Fig. 11.15 RTD cumulative functions of a single screw tangential counter-rotating twin-screw extruder (TCTSE) under matched and staggered conditions, and the back-mixed extruder reactor. [Reprinted by permission from Y. Lu, Ph.D Dissertation, Department of Chemical Engineering, Stevens Institute of Technology, Hoboken, NJ, 1993.]...

Oxidation of the trialkylaluminum mixture is carried out using dry air in agitated batch reactors in the ALFOL alcohol process. Reactor temperature is maintained at approximately 35°C by cooling and the oxidation is operated at about 50 psig. Approximately six hours is required for each batch of growth product to be completely oxidized. The oxidation reactors are operated in staggered fashion to minimize the maximum heat load. 

All reactors will operate on identical staggered schedules. 

Fig. 5.22 Surface of response for temperature optimization of continuous staggered CPBR with chitin-immobilised P-galactosidase, based on data in Table 5.3, considering the annual cost of reactor operation as the objective function...

Material and utilities requirements for new products—will they overload existing system Can staggering of their running time be done to distribute the load more uniformly on motor control centres, electrical cables, hoists, DG sets, belt conveyors. Reactors, and cooling systems—if there are some common ingredients for old and new products ... 

Reaction modelling of a microstructured billing film reactor incorporating staggered herringbone structures using eddy diffusivity concepts. Chem. Eng. 227, 66. 

SCR, SAR, SHR Serpentine channel reactor, split and recombine reactor, staggered herringbone reactor... 

The SRVs and DPVs are actuated in groups of valves at staggered times as the reactor undergoes a relatively slow depressurization. This minimizes reactor level swell during the depressurization, thereby enhancing the passive resupply of coolant by the GDCS. 

The staggered arrangement leads to a favorable height-to-width ratio of the reactor building. This simplifies verification of its stability in the case of loads resulting from external impacts (e.g. earth-quake, explosion blast wave). 

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