Conical cylindrical

Squire [364] and Porath [300,301] developed geometrical pore models for gel chromatography media. Squire considered a gel with a set of conical, cylindrical, and rectangular crevices, and found the pore volume, assumed equal to the partition coefficient K y, to vary as... 

The structure of the circulative impinging stream dryer developed is sketched in Fig. 6.13, in which the flow configuration of vertical two impinging streams is employed. The equipment consists of three basic parts mounted co-axially the body, the upper and the lower accelerating tubes. The body is of a conical/cylindrical shape with different diameters. The lower-middle part of the body is a cylinder with a relatively... 

Typical mature roots have different shapes (conical, conical-cylindrical, cylindrical, fusiform) and different sizes (3 to 15 centimeters in diameter), depending on variety, age and growth conditions. The color of the outer peel varies from white to dark brown. The cross-section of cassava roots shows the two major components which are the peel and the central pith (Figure 12.1). The peel is composed of the outer layer (called the periderm) and the inner layer (called the cortical region or cortex), which contains sclerenchyma, cortical parenchyma and phloem tissue. The large central pith of the roots is the starch-reserve flesh, comprised of cambium and parenchyma tissue and xylem vessels. 

Figure 12.1 (a) Cassava roots with conical, conical-cylindrical, cylindrical and fusiform shapes (b) cross-... 

Note that in all these equations we have used the convention that the upper sign of the + and + symbols refers to upward particle movement (active state) and the lower sign to downward particle movement (passive state). The symbols D Dc, Ds, and Dy are called distribution factors, corresponding to conical, cylindrical, trapezoidal, and rectangular tube sections, respectively. 

The pressure gradient dP/dH) along the height of a spouted bed is small near the base and increases to a maximum value at the bed surface. In contrast to this, the pressure gradient in fluidization is constant, even in a conical-cylindrical bed. 

Fig. 8. Pressure drop curves for fluidization in conical and conical-cylindrical vessels (Gelperin et at, Gl).

This explanation for the existence of a peak pressure drop is supported by experimental results obtained by Manurung (M7), who measured pressure drops separately across the upper cylindrical part and the lower conical part of the bed contained in a conical-cylindrical column as a function of both increasing and decreasing air flow. It is seen in Fig. 9 that the pressure drop across the upper part of the bed, up to the point at which the spout breaks through, corresponds to that in a packed bed and remains the same irrespective of whether the flow is increasing or decreasing. A peak well before the onset of spouting occurs only in the curve for the lower... 

Particle-velocity profiles for several solid materials spouted in a 3.7-in. conical-cylindrical column, measured by the piezoelectric technique, have been reported by Mikhailik and Antanishin (M14, millet, silica gel, poly-... 

Designing cylindrical, conical/cylindrical, or tapered-shaped variable speed auger feed screws... 

The second part of the two-stage SBD is a conical-cylindrical device of traditional shape (Table 15.2). The drying capacity of this device was about 80 kg/h of dried com with 150°C air at a flow rate of about 200 m /h, which resulted in a moisture removal of about 5% in the falling rate period. 

In recent years, fluid-bed dryers with a central fountain (spouted) bed have become popular for drying of coal. The fountain bed is achieved in a conical-cylindrical apparatus (Figure 51.13). The hot gas stream supplied to the dryer by tube (3) carries away the coal grains supplied by screw (2) and moves them upward. The lifted coal grains fall aside and move downward along the annulus. 

The shape of an engineering object may be composed of predefined, controlled, and free form elementary shapes. On the other hand, geometric elements are linear and curved. Predefined shapes can be described by simple mathematics so that they are called analytical shapes. Linear analytical shapes are lines and flat surfaces. Curved analytical shapes are conics, cylindrical surfaces, cones, tori, and spheres. Circles and ellipses are the most common conics in engineering. Other conics are parabolas and hyperbolas. The form of predefined shapes is fixed. Any other shapes can be altered as controlled or free form. Controlled surfaces are created by surface generation rules such as tabulation, rotation, or sweeping. Free form shapes are free form curves and surfaces. They may have arbitrary shape however, their initial shape must be defined by curves or points for the procedures that generate them. 

Gu, B., 2004. Ballistic penetration of conically cylindrical steel projectile into plain-wovai fabric target - a finite element simulation. J. Compos. Mater. 38, 2049-2074. 

For creating a continuous jet we used a conical-cylindrical nozzle 8 mm in diameter for a drop-type jet we used hydropneumatic and ejector nozzles " The size of the drops was determined by trapping them with a sticky compoimd. (The median diameter of the drops obtained after emerging from the hydropneumatic nozzle was 275 M.) The specific pressure over the cross section of the jet was measured by means of a system of detectors and an MPO-2 oscillograph. 

The velocities of the jets emerging from hydropneumatic and conical—cylindrical nozzles greatly exceed those required for the transportation of the particles, and this ensures the removal of the particles from the zone of contact between the jet and the surface after being detached. 

Because of high turbulence in the spout and the regularity of particle mixing, different types of spouted bed are highly appropriate to the placement of spray nozzles for the purpose of particle formulation, such as granulation or coating. Two examples in which liquid spraying occurs directly at the entrance of the gas jet, and which results in a concurrent, upward flow of the droplets and gas with frequent droplet-partide collisions, are shown in Fig. 4.3. The equipment shown in Fig. 4.3a is of the conical-cylindrical type, whereas the cylindrical device of Fig. 4.3b is named Wurster equipment, after its inventor (Wurster, 1959). The main feature of... 

Fig. 4.2 Conical-cylindrical spouted bed, in contrast to the conical equipment of Fig. 4.1b.

Fig. 4.3 Spouted beds with circular cross-section and liquid spraying, (a) Conical-cylindrical ...

The previously explained method for the determination of the minimally required gas volume flow rate is of general applicability, but approximate. Alternatively, correlations that refer to a speciflc type of spouted bed may be used. A number of correlations of this type for conical and conical-cylindrical spouted beds are summarized in Tab. 4.1, based on an evaluation by Piskova (2002). The geometric quantities involved are illustrated in Fig. 4.10. All correlations of Tab. 4.1 lead to the minimal value of a Reynolds number ... 

Tab. 4.1 Correlations for the determination of the minimally required gas volume flow rate in conical and conical-cylindrical spouted beds.

Fig. 4.10 Characteristic dimensions of conical-cylindrical spouted beds.

Tab. 4.3 Correlations for the determination of the maximal bed pressure drop in conical, conical-cylindrical and prismatic spouted beds.

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