Size reduction equipment roll crushers

The selection guides given by Lowrison (1974) and Marshall (1974), which are reproduced in Tables 10.12 (see p. 465) and 10.13, can be used to make a preliminary selection based on particle size and material hardness. Descriptions of most of the equipment listed in these tables are given in Volume 2, Chapter 2 or can be found in the literature Perry et al. (1997), Hioms (1970), Lowrison (1974). The most commonly used equipment for coarse size reduction are jaw crushers and rotary crushers and for grinding, ball mills or their variants pebble, roll and tube mills. 

Figure 14.5-3. Types of size-reduction equipment (o) gyratory crusher, b) roll crusher.

Comminution, or particle size reduction of solids, is considerably different from that of the breakup of one liquid by dispersal as small droplets in another. Particle size reduction is generally achieved by one of four mechanisms (1) compression, (2) impact, (3) attrition and (4) cutting or shear. Equipment for particle size reduction or milling includes crushers (which operate by compression, e.g., crushing rolls), grinders (which operate principally by impact and attrition, although some compression may be involved, e.g.,... 

Figure 12.5. Jaw, roll, impact, and tumbling equipment for size reduction, (a) Blake-type jaw crusher operates at 200-300 strokes/min (Allis-Chalmers Co.), (b) Smooth roll crusher, for which operating data are in Table 12.8(b). (c) Swing hammer mill operating data in Table 12.7(a). (d) View of a conical ball mill, showing distributions of balls and material and crusting ranges data in Table 12.6(b) (Hardinge Co.). (e) Tube mill with three compartments, length to diameter ratio 3-5. (f) Rod mill in a cylindrical tumbler, LID = 1.2-1.6 data in Table 12.6(d).

BatteUe personnel contacted manufacturers and vendors of these types of crushers to determine the applicability of the equipment types to the specific requirements for the explosives-contaminated debris. Toothed-roll crushers would be unable to achieve the required size reduction. This type of equipment was not recommended by the manufacturers and/or vendors. 

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