Continuous batch

Ton-exchange systems in process appHcations may be batch, semicontinuous, or continuous. Batch operations are not common but, where used, involve a ketde with mechanical agitation. Injecting with air or an inert gas is an alternative. A screened siphon or drain valve is requited to prevent resin from leaving with the product stream. 

FIG. 13-63 (Continued) Batch distillation paths, (h) Methanol-acetone-chloroform system. 

By operating cycle. Filtration may be intermittent (batch) or continuous. Batch filters may be operated with constant-pressure driving force, at constant rate, or in cycles that are variable with respect to both pressure and rate. Batch cycle can vary greatly, depending on filter area and sohds loading. 

Size Reduction Combined with Size Classification Grinding systems are batch or continuous in operation (Fig. 20-11). Most large-scale operations are continuous batch ball or pebble mills are used... 

Mathews and Rawlings (1998) successfully applied model-based control using solids hold-up and liquid density measurements to control the filtrability of a photochemical product. Togkalidou etal. (2001) report results of a factorial design approach to investigate relative effects of operating conditions on the filtration resistance of slurry produced in a semi-continuous batch crystallizer using various empirical chemometric methods. This method is proposed as an alternative approach to the development of first principle mathematical models of crystallization for application to non-ideal crystals shapes such as needles found in many pharmaceutical crystals. 

Understanding the production process involves knowing the function of each step to be covered by the Q system. Typical issues that must be discussed include the different process steps, the functions of each step, the measurable technological parameters such as time, temperature, and pressure, the measuring units present, the available analysis techniques and tools, and the way the process is orgaifized (continuous, batch, convergent, divergent, etc.). 

Flow (m3/h) Continuous Batch Continuous Batch Continuous Batch... 

The introduction of samples via nebulizers requires that they are either pneumatically or peristaltically pumped into the nebulizer for aerosol formation. This restricts the range of viscosities that can be easily handled by the nebulizer. For example highly saline or oil samples may well have to be diluted by an order of magnitude or greater. This dilution can be carried out either in a batch mode or continuously. Batch systems are quite complex in design but the rate of analysis is high. It is often the case that where dilution is required, in addition, a fast rate of analysis is also desirable. Some batch systems have been introduced commercially, notably to monitor wear metals in the oil industry. 

Batch or continuous Batch Semi Semi or continuous Continuous... 

A second consideration is the operating mode continuous, batch, or semi-continuous. An extensive textbook on theory, design and scale-up of multiphase reactors was published by Gianetto and Silveston in 1986 [22], supplementing "Three-phase catalytic... 

Figure 6.5 Fisher esterification reaction using a continuous batch flow reactor.

One of the most important biochemical reactors is the fermentor. We provided a simple example of a batch fermentor in Chapter 4. But there are many other types including continuous, batch, and fed-batch. There are some other useful references in the literature.16-17... 

Table 7.3 lists the various NPD for the well-stirred batch mixer, the plug-flow system with recirculation, and the well-stirred flow system. Figures E7.12a and E7.12b plot the distribution in the batch mixer and the continuous batch mixer. Note that in batch mixers the distribution widens considerably with increasing mean number of passages, and the distribution is much skewed toward low numbers of passages in the flow batch system. Therefore, two mixers with the same mean passages may have very different distributions. 

Recent advances on the Ca-Br cycle were presented in an ANL paper. The original concept for this cycle involved solid phase reactions in a semi-continuous batch operation. The ANL paper reported on experiments that used a direct sparging reactor in the hydrolysis reaction to allow continuous production of HBr which is then electrolytically decomposed to produce hydrogen. The sparging steam was introduced into the molten bath of CaBr2 which yielded HBr in a stable and continuous operation. 

Continuous steeping offers several major advantages over conventional continuous-batch countercurrent steeping. Since each tank operates independent of all other steep tanks, pump failures or other mechanical problems do not significantly affect plant operation as occurs within a conventional system. Steep capacity can be expanded easily and discretely, and does not need to be tied with the old steep tanks. 

The distillation process can be carried out in continuous, batch or in semi-batch (or semi-continuous) mode. 

Continuous, batch, and flow injection modes of hydride generation have been used successfully [39-41]. In the commonly used continuous mode the sample and sodium borohydride solutions are pumped by using a dual-channel peristaltic pump into a mixing chamber. The volatile hydride gas and hydrogen are carried into the plasma with a flowing argon gas and the excess liquid is directed to the drain. 

Figure 5,2 Continued) Batch distillation of benzene-toluene at constant rellux ratio, Example 5,3, (a-e) McCabe-Thiele diagram for progressively reducing still concentration to 0,13 mole fraction benzene.

Figure 5.3 (Continued) Batch distillation of benzene tohiene with variable reflux ratio, Example 5.4. if) l/(xD - xw) vs. xw plot.

Du, W., Xu, Y., and Liu, D. 2003. Lipase-catalyzed transesterification of soya bean oil for biodiesel production during continuous batch operation. Biotechnol. Appl. Biochem.,38,103-106. 

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