Rotary Breaker

The rotary breaker (Hgirre 6.6) essentially consists of an outer cylinder with an inner rotating perforated cylinder fitted with lifters which is operated at the lowest speed that will cause a small particle on the liner to centrifuge. Coal is fed into one end of the rotating cylinder where it breaks because of the tumbling action due to gravity faU, and pieces less than the hole sizes (typically 1.5 in. [38 mm]) 

FIGURE 6.4 Relationship of specific energy to hardgrove grindability index for two size reduction devices. (From Meyers, R.A., Ed., Coal Handbook, Marcel Dekker, New York, 1981, p. 177.) 

The liners of a rotary breaker are screen plates that allow peripheral discharge of properly sized material (Hicks, 1951). The unit size is based upon the diameter and length (Roman, 1967)  

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Primary breakers that treat ROM coal are usually rotary breakers, jaw crushers, or roll crushers some of these are listed below. 

Rotary Breakers (Fig. 1). The rotary breaker serves two functions—namely, reduction in top size of ROM and rejection of oversize rock. It is an autogenous size-reduction device in which the feed material acts as crushing media. 

The hammer mill is a variant of the conventional rotary breaker uses a closed far end with a series of hammers in a hammer mill rotating at this end, which breaks the harder coal and rock so that it is less than hole size and leaves through the holes. 

The screw consists of a feed section, a rapid transition section, and a metering section a rounded forward end prevents stagnation. The breaker plate that converts the rotary motion of the melt into smooth, straight flow should have as many holes as possible both ends of each hole should be countersunk for streamlined flow. 

Vortex breakers 1. A device used to straighten out rotary flow in a duct a short distance after a fan. 2. A device found in a cyclone discharge fitted to reduce shell erosion by particulate abrasion. 

Fig. 1. Schematic of continuous smelter for porcelain enamel glass production where A is a raw batch hopper B, batch hopper mixer C, screw feeder D, refractory furnace E, burner for gas and air (oxygen) F, spout G, water-cooled rollers for quenching glass H, finger breakers to break glass ribbon I, horizontal vibratory conveyer J, hammer mill K, vertical vibratory conveyer L, surge bin M, rotary magnetic separator N, product container O, exhaust...

Tube mills Roller mills Peg and disc mills Cage mills Impact breakers Vibration mills Rotary cutters and dicers Ball, pebble and cone mills Tube mills Ring roll mills Ring ball mills Roller mills Peg and disc mills Cage mills Impact breakers Vibration mills Ball, pebble, rod and cone mills ... 

EC-2, BC-6, BC-11 Conveyors G-3 Roll compactor CR-4 Breaker SC-5 Screen X-7 Grate calciner H-8 Rotary kI In C-9 Fluorine scrubber E-10 Cooler... 

Figure 15. One type of rotary shaker used to evaluate emulsion breakers.

A plant of this size will have a battery breaker and shredder, separation plant to recover metallic lead, pastes, polypropylene and other plastic and a single rotary furnace of 7 - 8 m working volume. 

FIGURE 7.2 Designs of rotary foam breakers, (a) Six-blade turbine, (b) Six-blade vaned disc, (c) Two-blade paddle. (From Takesono, S., Onodera, M., Ito, A., Yoshida, M., Yamagiwa, K., Ohkawa, A., J. Chem. Technol. Biotechnol. 2003. 78. 48. Copyright Wiley-VCH Verlag GmbH Co. KGaA. Reproduced with permission.)... 

FIGURE 7.11 Commercial centrifugal rotary plate foam breaker with conic plates and peripheral foam feed. (From FUNDAFOM, Chemap AG, 1977. With kind permission from Springer Science-tBusiness Media Theor. Found. Chem. Eng., 37, 2001, 372, Vetoshkin, A.G.)... 

Thereafter, the batteries are either fed in their entirety directly to a rotary hammer mill for component separation and washing, or are manually emptied and washed. The battery tops are independently processed through a hammer mill to separate metal components from casing mbber and plastic. Direct-feed hammer mill breakers offer significant labour cost savings and add to overall efficiency, and represent the preferred approach. 

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