MILLING Flashcards
the mechanical process wherein rough rice is
transformed into a form suitable for human
consumption.
MILLING
Dehullers
under-runner disc type
rubber roller type
impeller type
whiteners
friction type
abrasive type
horizontal abrasive type
rice milling system
single pass system\
multi-pass system
husk and bran removal
are done in one pass and milled or white rice is produced directly out of
paddy.
single pass system
removing husk and removing
bran are done separately, and brown rice is produced as an intermediate
product.
multi-pass system
✓Foreign matters or impurities are removed to protect the
processing equipment and to improve the quality of the
product.
pre-cleaning
group of impurities
a. Large impurities
b. Small impurities
c. Impurities which are of the same size as the paddy grain.
one of the most advanced milling machineries
• works on the principle of centrifugal force and impact. –with rotating disc
which serves to accelerate the paddy being fed to the machine and a
rubber ring which absorbs the force of impact created by the high velocity
grain. The impact of the grain on the rubber ring breaks the hull open.
• advantage over other existing rice mills is its ability to dehull different grain
size uniformly and without damage due to breakage of fissures which is
common in friction type machines.
• milling recovery ranges from 63% to 68%. It is bracketed under high
recovery machine group.
impeller type rice mill
single pass rice mill example, then parts
centrifugal huller on friction type whitener
accelerating disc, blower, pinawa, impact huller, metal resistance blade, bran, kiskisan
Rice husk and broken rice are removed
from the hulled material at the
winnowing section which is referred to as
aspirator.
husk aspiration
tro or pols. The coefficient of friction of paddy is greater than that of brown rice.
tro
t or f. The specific gravity of the paddy is lower than that of brown rice.
tro
TF. The buoyancy of the paddy grains is lighter than that of brown rice.
true
Simple vibrating deck and air blower that suspends the grain
from the stones. The stones are thrown off in one end and the
brown rice in the other end.
DE-STONING
