Agitated vessels, jackets

This chapter reviews the various types of impellers, die flow patterns generated by diese agitators, correlation of die dimensionless parameters (i.e., Reynolds number, Froude number, and Power number), scale-up of mixers, heat transfer coefficients of jacketed agitated vessels, and die time required for heating or cooling diese vessels. 

Equations for calculating inside film coefficients (hj) of jacketed agitated vessels... 

Surface area for heating or cooling agitated vessels can be provided by eidier external jacketing or internal coils (or tubular baffles). Jacketing is usually preferred because of ... 

Heating or cooling of process fluids in a batch-operated vessel is common in the chemical process industries. The process is unsteady state in nature because the heat flow and/or the temperature vary with time at a fixed point. The time required for the heat transfer can be modified, by increasing the agitation of the batch fluid, the rate of circulation of the heat transfer medium in a jacket and/or coil, or the heat transfer area. Bondy and Lippa [45] and Dream [46] have compiled a collection of correlations of heat transfer coefficients in agitated vessels. Batch processes are sometimes disadvantageous because ... 

Heat Transfer in Jacketed, Agitated Vessels/Ketdes... 

Baker and Walter report tests performed on open jacketed agitated vessels and published some of the limited results for this type of equipment. These data indicate the effects of jetting the fluid at various velocities into the jacket. 

The crystallizer was an agitated vessel with an Inside diameter of 9.0 cm and a volume of about 1 1. It was equlppet with four vertical baffles, a water jacket to keep the solution temperature constant, and a nozzle through which nitrogen gas was Introduced In several experiments to suspend a speed crystal more effectively In the solution. Agitation was accomplished with a 5.0 cm stainless steel marine propeller having three blades driven by a variable speed motor. 

The inside him coefficient / , of an agitated vessel depends on the type and degree of agitation. Geankoplis1 gives parameter values, which have been drawn from many sources, for a jacketed CSTR. The basic equation is... 

PVC bulk polymerizations are two-slage processes in which a very porous PVC seed particle is produced in a vessel provided with very high speed agitation. The wet polymer powder from this stage is fed to horizontal autoclaves in which the polymerization is finished. Reaction heal is removed by cooling the helical ribbon blender-type agitators as well as the vessel jacket. 

Step 10. The wetcake produced in the reactor centrifuge is conveyed to a resin neutralizer, another large, jacketed, agitated vessel, where the HCI in the resin is neutralized with sodium bicarbonate in the reaction... 

An agitated vessel is used for heating 500 kg/min of an aqueous solution at 15°C by saturated steam condensing in the jacket outside the vessel. The vessel can hold 6200 kg of the aqueous solution. It is fabricated from 15-mm-lhick sheet of 1.0 percent carbon steel [k = 43 W/m K), and it provides a heat transfer area of 12.0 m . The heat transfer coefficient due to agitation is 5.5 kW/m K, while the steam condensation at... 

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