Idaho semi-weekly world. [volume] (Idaho City, Idaho Territory) 1875-1908, 1893-01-20
HOW FLOUR rs MADE.
= JOURNEY THROUGH 4 MODEM
ROLLER PROCESS MILL.

wheat Il First Broken by Rollers ana
/ Gradually Crushed Into Flour bv sev.
erai series Of Other Rollers -separat-
Ing the Fine Flour from Bran.
Letus enter roller process mill and see
its devices for reduction and separation at
work. First Of all we are shown the ma
chimes which. bymeans Of sleeves and Air
blasts, remove from the wheat its admfx-
ture Of cookies, tares, ships and dirt. Next
come the securing machines. stoutly
framed and covered with cases Of perfo
rated cast iron. These are fed from the
cleansers we have just sect, and their
duty is to cut of the head Of the grain.
leaving 1t In a perfectly secured and pol
ished condition for reduction by the roll
ers. Some millers prefer cases made Of
very heavy rolled wire Of square sections,
whose sharp, impinging edges exert a
greater effect than Is possible with wire Of
ordinary round form.
Cleaned and prepared, the wheat Is now
ready for the first pair Of rollers. These
are usually twenty-four inches long, nine
inches In diameter and bear twelve cor
rugations to the inch. In contour these
corrugations resemble the teeth Of q saw.
and vary with the kind Of wheat to be
treated. For the hardest varieties Of grain
they are not 30 sharp as for soft wheats.
To prevent their interIocking with each
other they wind around the rollers I'm q
gentle spiral. To avoid splintering the
hror how Al
necessary TO accomplish the work Of each
reduction. They are completely boxed in
50 as to be breast high, and through lit
tie glass window the miller can see how
their work Is going on. As rule the
rollers are Of chilled iron, tough enough
not to need recutting until after two to
five years. use. 5
Porcelain rollers give satisfactory re-
suits, but their employment Is limited.
Chilled iron Is easier to manufacture and
repair. AS we watch the first pair Of roll
ers at work we observe that one Of them
revolves faster than its mate, so that a
grain Of wheat caught or the projection Of
slow roller is stretched out or unfolded
by the projection of the quick one. This
action it is which opens the grain 30 as to
shell out the middlings without at the
same time making more than trifing
quantity Of -four A point just here to
which the miller pays particular attention
is keeping these rollers at the right dis
lance apart. II too far from each other
they take no hold of the wheat. If too
near they mash it into fakes which resist
the -four separating process following up
the rollers work
When wheat has passed through the
first pair of rollers the product is con-
Quoted to scalping reel. This reel is a
revolving cylinder, covered with wire, hav-
ing about 324 openings to the square inch
As the meal is carried up its ascending side
the -four and middlings fall through. The
axis of the cylinder is inclined, and the
portions of wheat stock which cannot get
through its meshes gradually find their
way to the cylinders end or "tail," there
to be taken to second pair OF rollers for a
second reduction, In principal essentially
the same as the first. To the second pair
of rollers succeed others until fifth or
even sixth pair is reached. Each pair
has more corrugations to the inch than it's
predecessors, and has its two rollers placed
nearer together.
In following the partly broken wheat to
the second pair of rollers we left behind
us for moment the -four and middlings
due to the first pairs action. These two
products, the miller reminds us, were de
livere6 by the scalping reel as mixture.
He now submits them to boiling reel, a
frame clad with silk having hundreds or
| thousands of apertures to the square inch.
! This reel is cylindrical, form much pre-
| ferable to the six sided shape of old pat
| terms. Through its apertures the -four
readily passss. leaving the middlings in
/ the reel In this way scalping and boiling
reels follow up each successive pair of
rollers, their meshes gradually becoming
/ finer and finer. How much finer depends
/ upon the character Of the wheat and the
general conditions under which mill is
| operated. As a rule the silks run one
number or size finer at each reduction.
We are shown a variety of cloths, all Of
European make, ranging from SIC to Is, 900
meshes to the square inch.
The durability of these silks is astonish-
/ ing. With soft wheat reel will serve six
or seven years and remain In good condi-
ton. Wheat attracts moisture SO readily
from the atmosphere that its dampness
foretells coming storm as certainly as a
falling barometer. On muggy days boiling
is SO much retarded that if possible the
miller slows down operations.
Under his guidance we now retrace our
steps to where we left the boiling reels de-
livering their middlings. We are now to
see what becomes of them. Mixed as they
are with particles Of bran, fiber and Other
impurities, they go to separator, con
trived upon principle as simple as it is
effective.
In windy weather, If we inspect the dust
borne to the window sills at the various
levels of tall building, we find decided
difference in its quality. The dust which
has risen to the top story Is much finer
than the dust deposited at the ground floor
The wind has carried light particles fur
Their than heavy ones. This action is imi
tated in the aspirators and purifiers of oul
mill. A sharp blast of air is directed
against the mixture of middlings, brar
and fiber. As the finer and lighter frag
meuts can be blown further than the
heavier and coarser, they are separated
into their special boxes or chutes. Puri
fiers are made in a variety of designs. Thest
machines are set at the task Of dividing
middlinss into coarse, fine and low grades
incidentally freeing them from any admix
ture of bran and germ they may contain.
As the rollers have gradually turned ou
a finer and finer product, point is reachet
where middlings, germ and bran are de
livered in particles very similar in thei
minute size and weight. The differences
which exist between them are too Sigh
for any process of separation to seize upon
The silk of the boiling reel can divid,
small particles from large; the aspirasor
or purifier of other type, can disunite ligh
particles from heavy ones. Here tn
n...:.,. Nr,;t If both is nqssad Now b'