Rotating drums

Rotating-Drum Type This type (Fig. 11-55 a and b) is not an adaptation of a material-handling device (though volumetric material throughput is a first consideration) but is designed specifically for... 

Essentially a rotating drum mounted on slight incline. 

Some materials that are prepared in the molten state are converted advantageously to flake form by cooling a thin layer continuously on the surface of a rotating drum. Another way is to spray cool from the melt, using a spray diyer with cold air. Thus, massive cooling and subsequent pulverizing are avoided. See the Index for details of these other methods. 

Rotating-drum-type and belt-type heat-transfer equipment forms granular products directly from fluid pastes and melts without intermediate preforms. These processes are described in Sec. 5 as examples of indirect heat transfer to and from the solid phase. When solidification results from melt freezing, the operation is known as flaking. If evaporation occurs, solidification is by diying. 

A valveless configuration in which there is no bridge setting and the sealing between the rotating drum and the stationary outlet is by circumferential o rings rather than by a face seal used on conventional valves. 

Rotating Drum Filter Low space requirements Can be polymer dependent... 

The water-repellent wool is shredded by a flail and pneumatically transferred to a rotating drum nodulator to be further processed before bagging. 

Gray oxide can be produced by a milling process, which, strictly speaking, does not mill the material. A rotating drum is filled with solid balls or ingots of lead. 

This type of filter can be used for removal of Penicillium and Streptomyces mycelia in the production of penicillin and streptomycin, respectively.5 In these processes the rotary drum filter is used with a pre-coated cloth filter with filter aid the filter cake is removed by a knife blade which scrapes the cake from the rotating drum. 

The time duration which corresponds to the movement of the surface of the rotating drum thru this distance is calcd, and this is the time which was required for the deton of the column of known length of expl which lay between the two wires. From this, the vel of deton in m/s is computed... 

Optical Chronograph. Same as Rotating Drum Ophorite. A Brit perchiorate expl used during Chronograph, described briefly under Chrono-... 

Rotating drum granulators have length to diameter ratios of 2-3, speeds of 10-20 rpm, pitch as much as 10°. Size is controlled by speed, residence time, and amount of binder 2-5 mm dia is common. 

Laboratory reactors for studying gas-liquid processes can be classified as (1) reactors for which the hydrodynamics is well known or can easily be determined, i.e. reactors for which the interfacial area, a, and mass-transfer coefficients, ki and kc, are known (e.g. the laminar jet reactor, wetted wall-column, and rotating drum, see Fig. 5.4-21), and (2) those with a well-defined interfacial area and ill-determined hydrodynamics (e.g. the stirred-cell reactor, see Fig. 5.4-22). Reactors of these two types can be successfully used for studying intrinsic kinetics of gas-liquid processes. They can also be used for studying liquid-liquid and liquid-solid processes. 

Studies of relatively slow segregation in closed sample configurations, such as the rotating drum, are perhaps the easiest granular experiments to perform by MRI. Measurements can be made with the sample stopped the process can continue to evolve between the measurements. As mentioned above, MRI is much easier to perform on stationary systems as opposed to systems undergoing motion. 

F, produced by natural gas combustion in air, are used to heat the beans in a perforated steel rotating drum. Relatively small quantities at a time are heated for a total of only 5 min. When the beans have reached the selected internal temperature and corresponding color, they have already been moved through the oven to a heat lock. At this point they are released and rapidly cooled, with a fine water spray or air draft, so that further pyrolytic changes in the bean are prevented. 

It is evident that different roasting practices will produce a variety of chemical effects in the bean. Recycling of hot effluent gases, perforation of the rotating drum, and use of radiant heat will each give different chemical character to the final roasted coffee bean. 

The molds are cast and allowed to cool for a suitable time, often 30 to 40 min, before shaking out the castings. The shakeout work may be supplied by a vibrating conveyor or a rotating drum, which cause the molds to be broken up by the vibration, exposing the casting for removal. The sand... 

A vacuum rotary-drum filter consists of a porous septum that surrounds an empty rotating drum. The bottom of the drum is immersed in the sludge liquor. A vacuum pulled on the inside of the drum causes the water to enter the drum through the filter medium. The solids that cannot pass through are retained on the surface of the medium. As the drum rotates, the solids at the surface of the septum are lifted out of... 

Rotating drums, disks, and to a lesser extent, cones are used in continuous large-scale balling of iron ores (E3). A pelletizing disk of industrial type is shown in Fig. 1. Fertilizers are granulated in twin-shaft pug mills, drums,... 

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