to th position see pages to Article No LP B3-HH24A Bevel-helical gearboxes B3

Flender/Flender Gear Units/Bevel-helical gearboxes B3

Pulses need to be cleaned of dust, dirt, immature grains, and other extraneous materials. They have to be graded according to size. These operations are carried out by two typesof machines: rotary- or reel-type sieve-cleaners, and reciprocating sieve cleaners. The at,reciprocating sieve-cleaners are extensively used both by large- and small-scalemillingunits. However, this type is gradually being replaced by rotary-type cleaners in large mills. 2.3.3 Rotary-Type Screen Cleaner The construction of rotary-type screen cleaner is similar to one used in quarrying for grading of different-sized stones. It consists mainly of four compartments of screens ttedon shaft. The machine is usually placed on sloped platform and operates at low speed(1 rpm) for achieving better performance. The body of the machine is generallyconstructed of wood or mild steel. Advantages of this type of cleaners are lower dust andnoise pollution and low-maintenance cost. 2.3.4 Reciprocating Screen Cleaner The reciprocating-type cleaner consists of two or three compartments of different-sized screens (depending on the type of pulse being milled) and also suction arrangement toremove dust and other light particles. Normally pulses are graded into two or three differ-ent sizes. Screens would usually be at an angle of about 5 degrees, with an amplitude of close to 1 mm; the speed is about 3 rpm. The size of the reciprocating cleaner varies from 1 /H1 cm to 2 /H1 cm depending on the required capacity. 2.3.5 Pitting and Dehulling MachinesThese machines consist of emery-coated rollers, either cylindrical or slightly tapered, rotat- ing in cage of perforated sieve (Fig. . Cylindrical rollers are mounted at an incline, whereas the tapered rollers are mounted perfectly horizontal. These arrangements help in easy movement of the pulse. The size of different cylindrical rollers varies from 7 /H1 cm to 9 /H1 cm. The tapered rollers come in different sizes, such as 1.5 /H1/H1 cm to 3.0 /H1.0/H1 cm. The an