Wall cones

The entering fluid flows downward in a spiral adjacent to the wall. When the fluid reaches the bottom of the cone, it spirals upward in a smaller spiral at the center of the cone and cylinder. The downward... 

The swan neck adapter of Fig. II, 56, 12 is useful for distillations as it permits the use of a capillary tube (held in position by a short length of heavy-walled rubber tubing) not sealed to a ground joint. It may also be used for inser tion of a thermometer or a gas-inlet tube in the narrow neck and a reflux condenser into the ground joint this device virtually converts a three-necked into a four-necked flask. Common sizes are cone fil9, 24, 29, or 34 socket 19, 24 or 29. 

The spray pattern is also important. A soHd cone pattern mixes less well than a hoUow cone, sheet, or multiple jet patterns. Drops that enter along the edge of the spray pattern nearest the exit have less time to heat up and evaporate. Drops that enter along the edges of the spray pattern nearest the walls may not fully evaporate before hitting the walls, resulting in erosion and corrosion of the brick. 

SpiralTlevator Materials are moved upward by the centrally located spiral-type conveyor in a cylindrical or cone-shaped Nautamix vessel (Fig. 37c and d). Blending occurs by the downward movement at the outer walls of the vessel. The vessel serves the dual purposes of blending and storage. In these mixers the screw impeller actively agitates only a small portion of the mixture and natural circulation is used to ensure all the mixture passes through the impeller zone. In the case of Nautamix, an Archimedian screw lifts powder from the base of a conical hopper while progressing around the hopper wall. 

Fig. 4. Examples of expanded dow bins showing where funnel dow becomes mass dow (a) funnel dow cone modified with mass dow transition hopper, where BP = outlet width, DF = diameter, 0 = end-wall angle, and 0 = side-wall angle (b) long funnel dow slot modified with mass dow cones, where...

In most rotational viscometers the rate of shear varies with the distance from a wall or the axis of rotation. However, in a cone—plate viscometer the rate of shear across the conical gap is essentially constant because the linear velocity and the gap between the cone and the plate both increase with increasing distance from the axis. No tedious correction calculations are required for non-Newtonian fluids. The relevant equations for viscosity, shear stress, and shear rate at small angles a of Newtonian fluids are equations 29, 30, and 31, respectively, where M is the torque, R the radius of the cone, v the linear velocity, and rthe distance from the axis. 

A particle entering the cyclone finds a poiat where its velocity with respect to the fluid is equal to the radial velocity, and hence is at rest with respect to radial movement to or from the wall. Because the radial velocity changes with radius, the particle spirals down the cone section, foUowiag a path defined... 

Pipe size, in (mm) Pipe outside diameter, in (mm) Cone outside diameter, in (mm) Wall thickness, in (mm) Cone angle. Approximate weight per foot, lb (kg)... 

These devices are replacing the older tank and spiral-conveyor devices. Better provisions for speed and ease of fill and discharge (without powered rotation) minimize downtime to make this batch-operated device attractive. Heat-transfer coefficients ranging from 28 to 200 W/(m °C) [5 to 35 Btu/(h fF °F)] are obtained. However, if caking on the heat-transfer walls is serious, then values may drop to 5.5 or 11 W/(m °C) [1 or 2 Btu/(h fH °F)], constituting a misapplication. The double cone is available in a fairly wide range of sizes and construction materials. The users are the fine-chemical, pharmaceutical, and biological-preparation industries. 

For proper use of the equations, the chamber shape must conform to the spray pattern. With cocurrent gas-spray flow, the angle of spread of single-fluid pressure nozzles and two-fluid pneumatic nozzles is such that wall impingement wiU occur at a distance approximately four chamber diameters below the nozzle therefore, chambers employing these atomizers should have vertical height-to-diameter ratios of at least 4 and, more usually, 5. The discharge cone below the vertical portion should have a slope of at least 60°, to minimize settling accumulations, and is used entirely to accelerate gas and solids for entty into the exit duct. 

Reentrainmeut from the bottom of the cyclone can be prevented in several ways. If a typical long-cone dry cyclone is used and hquid is kept continually drained, vortex entrainmeut is uuhkely. However, a vortex breaker baffle in the outlet is desirable, and perhaps a flat disk on top extending to within 2 to 5 cm (0.8 to 2 in) of the walls may be... 

The split was centered in a distinct zone of severe wall thinning from the external surface. Close examinations of this surface under a low-power microscope revealed a forest of small, well-formed brass cones pointing straight up from the surface (Fig. 11.16). The external surface on the opposite side retained its smooth, original surface. 

Fig. 12-5 Voltage cone AU and pipe/soil potentials at a wall entrance in a steel-reinforced concrete foundation.

Structures or pits for water lines are mostly of steel-reinforced concrete. At the wall entrance, contact can easily arise between the pipeline and the reinforcement. In the immediate vicinity of the pit, insufficient lowering of the potential occurs despite the cathodic protection of the pipeline. Figure 12-7 shows that voltage cones caused by equalizing currents are present up to a few meters from the shaft. With protection current densities of 5 mA mr for the concrete surfaces, even for a small pit of 150 m surface area, 0.75 A is necessary. A larger distribution pit of 500 m requires 2.5 A. Such large protection currents can only be obtained with additional impressed current anodes which are installed in the immediate vicinity of the pipe entry into the concrete. The local cathodic protection is a necessary completion of the conventional protection of the pipeline, which would otherwise be lacking in the pit. 

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