Jacket-Cooled

The Q term in Eq. (2.5) depends on the heat removal scheme used. If a circulating jacket water system is used, the jacket is essentially at one temperature Tj, and the heat transfer rate depends on the jacket area, the overall heat transfer coefficient and the differential temperature driving force 

= jacket heat transfer area (m2) = 7rDL D = reactor diameter (m) 

The consumption of the cooling medium is calculated from an energy balance around the perfectly mixed jacket at temperature T,. Constant physical properties of the cooling medium are assumed 

The typical reactor design situation is to be given the feed conditions (flowrate, temperature, and composition), the kinetic information, and the desired conversion. The problem is to determine the temperature and the size of the reactor. 

In general, the temperature of the reactor is established in a number of different ways that depend very strongly on the chemistry and the kinetics. For the simple irreversible reaction studied in this section, in which the only issue is to achieve the desired conversion, it would appear that the reactor temperature should be made as high as possible. This would give the largest specific reaction rate and therefore the smallest reactor size, thus minimizing capital investment. However, as we show below, there are dynamic controllability considerations that must be factored in when selecting reactor temperature. For the more complex reactions considered in later sections (such as reversible, consecutive, or simultaneous reactions), in which issues of both conversion and yield are important, the selection of reactor temperature must consider the production of undesirable products as well as reactant conversion. 

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All refluxed melt will refreeze if reflux supphed equals that computed by Eq. (22-8). When reflux supplied is greater than the minimum, jacket cooling in the refining zone or additional cooling in the recoveiy zone is required to maintain product recoveiy. Since high-... 

One significant practical difference in use of polytropic head is that the temperature rise in the equation is the actual temperature rise when there is no jacket cooling. The other practical uses of the equation will be covered as they apply to each compressor in the later chapters. 

As in most jacket-cooled compressors, the cooling acts as a heat sink to stabilize the cylinder dimensionally. The jacket outlet temperature should be around 115 F and be controlled by an automatic temperature regulator if the load or the water inlet temperature are prone to change. 

Can use shell-and-tube exchanger with jacket cooling water or aircooled exchanger. 

Compressor Jacket Cooling. The compressor jacket cooling water does not have to be as warm as does the gas engine... 

An exception to the above are fatty acid methyl esters, which, due to the reaction mechanism involving molecular rearrangements with excess S03, have to be sulfonated at a slightly higher mole ratio of S03 to methyl esters (namely, 1.15-1.20/L). Outside the reaction tubes, in the reactor jacket, cooling water is circulated to control the liquid-film temperature and removing the reaction heat. 

An example of a low conversion reactor would be a conventionally agitated kettle with large turbine agitators and jacket cooling. The utility of this type of reactor can be extended to intermediate conversions by the use of anchor or helical agitators to partially overcome heat transfer and mixing problems at higher viscosities. 

Water Jacket Cooling Water Reflective Gold Film... 

St., Newark 5, New Jersey 07105. The lamp was suspended vertieally in a cylindrical, double-walled, Pyrex jacket cooled by flowing water. The inside diameter, outside diameter, and length of the cooling jacket were 3, 4, and 22 cm., respectively. The cooling jacket was clamped in place ca. 5 cm. from the reaction vessel to allow the cooling bath to be raised into position. The use of the 200-W. lamp did not alter the reaction time. 

CONTINUOUS STIRRED TANK REACTOR EQUILIBRIUM REACTION AND JACKET COOLING A < = > B ... 

A first-order, exothermic reaction occurs within a continuous stirred-tank reactor, equipped with jacket cooling, where the kinetics and reactor schemes are... 

CSTR WITH EXOTHERMIC REACTION AND JACKET COOLING Dynamic solution for phase-plane plots Located steady-states with THERMPLO and use same parameters. 

The stability of a first-order exothermic reaction A—>B, in a single CSTR with jacket cooling has been studied by Seborg (1971), and the usefulness of simulations for this type of investigation has been emphasised by Luus (1972). The influence of sinusoidal, feed-temperature variations is corrected by simple... 

CONTINUOUS STIRRED TANK REACTOR REVERSIBLE REACTION AND JACKET COOLING HEAT AND TEMPERATURE EFFECTS WITH CP = F(T)... 

Semi-batch reactor with heat production Feedback control of feed stream Jacket cooling... 

The example simulation THERMFF illustrates this method of using a dynamic process model to develop a feedforward control strategy. At the desired setpoint the process will be at steady-state. Therefore the steady-state form of the model is used to make the feedforward calculations. This example involves a continuous tank reactor with exothermic reaction and jacket cooling. It is assumed here that variations of inlet concentration and inlet temperature will disturb the reactor operation. As shown in the example description, the steady state material balance is used to calculate the required response of flowrate and the steady state energy balance is used to calculate the required variation in jacket temperature. This feedforward strategy results in perfect control of the simulated process, but limitations required on the jacket temperature lead to imperfections in the control. 

A chemical reactor is cooled by both jacket cooling water and condenser cooling water. A mathematical model of the system has yielded the following openloop transfer functions (time is in minutes) ... 

Jacket cooling systems, if provided, shall be designed to positively prevent the process stream from leaking into the coolant. Coolant passages shall not open into casing joints. 

Because of the highly exothermic nature of acrylonitrile polymerization, bulk processes arc not normally used commercially. Howevei. a commercially feasible process lor bulk polymerization in a continuous stirred lank reactor has been developed. The heat nl reaction is controlled hy operating at relatively low conversion levels and supplementing the normal jacket cooling with reflux condensation of umcaclcd monomer... 

Changing Kc increases the slope of the heat removal line because its slope is 1 + K If a bifurcation diagram is drawn for this nonadiabatic case with Kc as the bifurcation parameter and the jacket cooling temperature is the temperature of the middle steady state ym, we obtain a pitchfork type bifurcation diagram as shown in Figure 9 (A-2). 

Kinetic studies of the defective batch showed that the jacket cooling was capable of dissipating the amination heat up to approximately 190 °C. 

The temperature control of the CSTR can be realized in different ways, such as an adiabatic reaction without cooling system or with jacket cooling. These different modes of operation, and the effect of the operating parameters on the stability of the reactor, are described in the following subsections. 

Without jacket cooling, only three terms remain in the heat balance the accumulation, the heat release rate of the reaction, and the sensible heat due to the temperature difference between the feed and the reactor contents. Thus, we obtain... 

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