cast iron mill roll

Specifications

:: Rice Roller & Polisher :: Specifications

Salient features to get maximum output from Rubber Dehusking Rolls. The life of rolls is not only governed by its quality but also several other factors such as variety and type of paddy (Short/Long, Raw/Parboiled), climatic conditions, Peripherals speed of Rolls distribution of paddy, moisture contents of paddy, dehusking percentage of paddy, clearance between the rolls cleaness of the paddy, cooling arrangement of rolls, eccentricity in shaft and operators skill. Some of these parameters e.g. Variety of paddy and climatic conditions are beyond the control of Rice millers but others can be controlled very well for which, following steps must be taken into account to get maximum output for rubber rills.

PERIPHERAL SPEED OF ROLLS

The Rolls rotate at different RPMS and in opposite direction. Normally the peripheral speed of the adjustable roll is about 25% slower than the fixed roll. Hence the former wears slower comparatively even as the rolls are interchangeable in position (Fig A). From above illustrations, it is clear that the pair of rolls must be changed at a time rather that the individual roll.

AGE OF ROLLS

Rubber rolls deteroiates gradually as shown in Fig. B below, hence they can be stored only for limited period and yet it is recommended that they should be utilized between 3 and 6 months after production. Therefore, rice millers should not store rubber rolls more than one year, rather a continuous supply should be maintained in order to receive optimum efficiency.

VARIETY OF PADDY

The size and roughness of husk affect the performance of the rolls when long grain varieties of paddy are dehusked by the contact area of the grain with the rubber is much longer compared to short grain varieties consequently, the wear is higher and the life of the roll is considerably reduced. The same quality of roll can dehusk about 200mt of short variety of paddy grown in Japan against only about 100mt of long grain paddy variety in tropical countries. When parboiled paddy is milled the husk gets loosened and thus spilt easily. Therefore same quality of rolls can dehusk about 300mt of parboiled paddy against only 200mt of raw paddy.

Quite often the grain distribution device does not function correctly and the roll surface wears out unevenly. Therefore, the Roll surface is corrected by removing the rubber from the sides of the roll. To obtain optimum life of the Roll and efficient dehusking performance. The Grain should be evenly distributed.

PRECAUTION FOR OPERATORS

1. At the time of installation of new rubber roll on the mendal, screw should be tight.
2. At the time of installation sleeve rubber roll it must be checked that the holes for nut and bolt should be of proper size and round in shape rather than elliptical to avoid vibrations.
3. The perforated Jali used for manufacturing rubber dehusking roll should be of proper size otherwise it may be distorted at the time of installation of rubber roll on mendal of the machine.
4. Don't use hammer on rubber rolls inner bore while fitting it on the mendal.
5. Set right the roll on mendal in quite straight in position as shown in the Figure. Please check both the keys of the roll. They should be in the center of the grooves of the mendal at the time of switching on the machine for applying pressure.
6. Paddy must be cool, clean and sound having fair average specifications.
7. Moisture contents of paddy to be dehusked should not be more than 14% to 15% i.e. it must be dried upto the safe level.
8. Paddy should not be damaged or partially damaged.