Crushing rolls

Brechungs-ebene, /. (Optica) plane of refraction. -exponent, m. refractive index, -ge-setz, n. law of refraction. -Index, m. refractive index, -k effizient, m. coefficient of refraction. -kraft, /. refractive power, -messer, m. refractometer. -verhaltnis, n. refractive index, -vermfigen, n. refractive power, -winkel, m, angle of refraction, Brech-walzwerk, n. crushing rolls (or rollers), crushing mill. >weln, m. (Pharm.) wine of antimony, antimonial wine, -weiustein, m. tartar emetic, -werk, n. crusher, -wurzel, -wurz,/. ipecacuanha, ipecac. 

Quetsch-walze, /. crushing roll, -werk, n. crushing mill, crusher squeezing apparatus, -wirkung, /. squeezing action or effect, -wunde, /. bruise, contusion. 

Crushing rolls a) bowl mill classification dicers ... 

If crushing rolls 1 m diameter are set so that the crushing surfaces are 12.5 mm apart and the angle of nip is 31°, what is the maximum size of particle which should be fed to the rolls ... 

The single roll crusher shown in Figure 2.13 consists of a toothed crushing roll which rotates close to a breaker plate. Figure 2.14 is an illustration of an industrial model. The material is crushed by compression and shearing between the two surfaces. It is used extensively for crushing coal. 

Crushing rolls are extensively used for crushing oil seeds and in the gunpowder industry and they are also suitable for abrasive materials. They are simple in construction and do not give a large percentage of fines. 

The roller mill consists of a pair of rollers that rotate at different speeds, a 3 1 ratio for example, in opposite directions. As in crushing rolls, one of the rollers is held in a... 

The only significant difficulty in processing occured at carding where static electricity caused the web to behave erratically. The static was controlled by carding the cotton with a static bar in place under the web just as it exited the crush rolls. Processing and yarn quality results for the 3 cottons made into 19.7 mg/m yarns at 13000 rpm spindle speed are shown in Table X. Spinning quality results for the Mississippi and California cottons that were made into 14.8 mg/m yarn are shown in Table XI. 

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.,... 

HR foam usually contains closed cells which become a cause of foam shrinkage. In general, therefore, immediately after demolding, the foams are passed through a crushing roll to break the closed-cell membranes, and are then cured in an oven. The choice of proper surfactant for HR foam is also an important solution to the problem of shrunk or collapsed foams. 

The crushing roll is a type of machine that has been in use for a great many years. It consists of two solid cylinders with bearings in the same horizontal plane, set fairly close together, the stream of rock to be crushed passing between the two. One or both of these cylinders may be positively driven. They are usually adjustable so that the rock may be reduced to a desired size. Rolls are usually made with a solid cylindrical core having removable shells which take up wear. These shells are made of hard steel, often so alloyed as to present a surface highly resistive to abrasion. 

The most favorable condition for crushing rolls is when the ratio of size of feed product does not exceed about 4 or 43 1. When this ratio is exceeded, the efficiency of the roll is greatly decreased and the power requirement increased. With the ratio of 4 1, the power is practically constant whether the ratio is applied to large feed and large product, or fine feed and finer product. The capacity of the machine, however, will usually be in proportion to the size, that is, with production on large pieces, the capacity will be greater than with reduction on smaller pieces other factors remaining constant. 

As to power, the accompanying formulae show the requirements for crushing rolls of all kinds. The power to drive rolls at normal speed, without load, varies for different sizes, speeds and makes of machines. An approximate idea being obtained from the following formula. ... 

Crushing rolls are very widely used for such work and are usually very satisfactory. The distance between the roll faces can be definitely set to the size of particle desired and there can be no oversize. There will be, however, a large percentage of underside because roll crushing is the result of direct compression, and consequently a good deal of fine dust is produced. Another objection to the use of rolls is that the crushing... 

For brittle materials, shear force is restricted to hammer mills, acting along with impact and attrition, as well as to toothed crushing rolls. The prerequisite for successful size reduction of particles is the existence of macro- or microstructure weaknesses (e.g., layered structure, schistosity) or differences in the characteristics of adjacent minerals (e.g., hardness, friability). Contrary to rocks and minerals, shear force is widely applied in soUd waste size reduction, as most of its constituents are soft, nonbrittle, plastic, and ductile, and, consequently, shear forces are effective. The various forms of shredders use shear force to reduce the size of solid waste constituents. 

Some sugar is still retained in the bagasse. Hence in some plants it is passed on an endless belt through a shallow trough containing water and then pressed once more in crushing rolls. This extract is added to the first juice. 

Forces commonly used in food processes for particle size reduction are compressive, impact, attrition (or shear), and cutting forces. More than one force usually participates in the comminution operation in industrial size-reduction equipment. In particular, crushing rolls use mainly compressive forces, hammer mills are based on impact, disc mills cause particle attrition through shear force application, and rotary knife cutters use cutting forces. 

PP-1 Surge Bin PP-2 Scale PP-3 Crushing Roll PP-4 Heats Conditioner PP-5 Hechanical Screw Press... 

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