Vessel dimensions

Batch mixing using fluidization has been successfully employed in many industries. In this case there is practicaUy no limitation to vessel dimensions. 

Vortex Depth In an unbaffled vessel with an impeller rotating in the center, centrifugal force acting on the fluid raises the fluid level at the wall and lowers the level at the shaft. The depth and shape of such a vortex (Rieger, Ditl, and Novak, Chem. Eng. ScL, 34, 397 (1978)] depend on impeller and vessel dimensions as well as rotational speed. 

Fig. 16.1. The weld between the shell and the end cap of the pressure vessel. Dimensions in mm.

Power is the external measure of the mixer performance. The power put into the system must be absorbed through friction in viscous and turbulent shear stresses and dissipated as heat The power requirement of a system is a function of the impeller shape, size, speed of rotation, fluid density and viscosity, vessel dimensions and internal attachments, and posidon of the impeller in this enclosed system. 

With consideration to the domestic industrial practitioner, the following illustrative examples utilize conventionally recognizable units as viscosity in centipoise, density in lbs/ft3, velocity in ft/sec, vessel dimensions in inches, and particle diameter in microns. 

Repeat Example 24-2 for the xylene (B) oxidation reaction carried out in an agitated tank reactor (instead of a bubble-column reactor). Use the data given in Example 24-2 as required, but assume the diameter D is unknown. Additional data are the power input without any gas flow is 8.5 kW the impeller rotates at 2.5 Hz the height and diameter of the tank are the same (h = D) the impeller diameter is DI3, and the impeller contains 6 blades assume ubr = 1.25usg. In addition to the vessel dimensions for the conversion specified (/B = 0.16), determine the power input to the agitator (P,). 

The solution is complicated by the fact that many of the parameters in the design equations depend on the vessel dimensions (h or D or V). In addition to the design equations, we give expressions for these parameters in terms of D. The result is a set of nonlinear algebraic equations to be solved for the unknown quantities, including D. We solve these by means of the E-Z Solve software (file ex24-3.msp). 

To validate both the particle velocity hypothesis and our scaling criteria, similar experiments were run in a number of different capacity V-blen-ders. Vessel dimensions are shown in Table 2, along with a schematic, shown in Figure 8. 

Feed to a spray dryer contains 20% solids and is to be dried to 5% moisture at the rate of 500 lb/hr of product. Pilot plant data show that a residence time of 6 sec is needed with inlet air of 230T, H = 0.008 lb/lb, and exit at 100°F. Ambient air is at 70°F and is heated with steam. Enthalpy loss to the surroundings is 10% of the heat load on the steam heater. The vessel is to have a 60° cone. Air rate and vessel dimensions will be found. 

Liddell MR, Deng G, Huack WW, Brown WE, Wahab SZ, Manning RG. 2007. Evaluation of glass dissolution vessel dimensions and irregularities. Dissolution Technol. 14 28-34. 

Westerterp et al, 1963), there is a minimum impeller speed for efficient operation above this, kLaL can be expressed as the sum of two terms, one related to impeller speed and diameter and vessel dimensions, and the other depending on the power per unit volume and the gas rate. The correlations for kLaL presented in this study are outlined in Table XXI. 

This section is devoted to the definition of the vessel dimension as long as the material properties. Typically, the dimension of the prototypes which are mannfactnred in onr Laboratory is a 1 litre bottle of 250 mm long for a 75.3 mm inside diameter. The thickness of the aluminium liner is 1.85 mm and the thickness of each layer of the laminate is 0.27 mm. The stacking sequence of the laminate is the following [+30] + [+50]4 + [90]3. This sequence means the liner is reinforced with 13 layers of composite 2 layers with a 30° angle, 8 layers with a 50° angle and finally 3 layers with a circumferential winding. 

The rates of these reactions depend on diffusion coefficients (and hence on pressure) and on the vessel dimensions and surface characteristics. 

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