Pullman herald. [volume] (Pullman, W.T. [Wash.]) 1888-1989, 1912-03-08
Drying Potatoes

lying 'iatOVS
The drying Of potatoes is an indus
try that has been developed in the
past five years in Germany, which
country grows One-third of the
worlds potato crop. During the past
year, under orders of the secretary
of Agriculture, an investigation has
been made in Germany of the starch
and dried potato industries, dealing
especially with machinery and meth
CHS in use. Germany has potato dry
ing plants with a combined yearly
capacity of nearly 25,OO0.OOO
bushels of potatoes, equal to more
than Z per cent of the average an
nual potato crop of the United States
for the three years ending with 1911.
The two general methods of manu-
facture are known as the roll system
and the drum system.
In the roll system the potatoes are
| steamed until softened, and then
passed between large revolving cyl
inders which are heated by steam.
The potato forms on the roll in
| layer, which dries and is scraped off
during a revolution of the roll. This
product has the appearance of one of
our breakfast foods known as corn
| flakes" and is used as a general sub
stitute for the fresh potato in the
|
household, in addition to being
ground to a flour and mixed with
other flours for bread making and in
making of cereal foods.
The drum system makes a product
at about half the manufacturing cost
of the roll system, and for all pur-
poses other than human food. the
| drum system is used. 1t consists. es-
sentially, of an iron shell about two
and one-half feet in diameter and
eight times this length. Through
this a heavy current of air is drawn
by means of fan, and the fire gases
from stove feed directly into it.,
the mixture of heated and cold air
being such as to make a temperature
of about 500 degrees f. at the en-
trance. From a cutting machine,
| clipped potatoes are conveyed to the
| slowly revolving drum, which is pro-
vided with an interior construction
that gives the potatoes the maximum
exposure to the drying action of the
hot air. The drying operation must
| be done on rather a large scale, as
small drums are not nearly so eff
ficient in proportion to size The
fuel requirements are about 800
pounds of coke, or its equivalent, for
one ton of potatoes, and the labor
requirements are small The ap-
| proximate cost of operation, includ-
ing fuel, labor, interest on invest
ment, taxes, wear, ETC., is $1.30 per
ton of potatoes. Four tons of pota-
| toes yield one ton of dried product
In Germany most of the product is
used as feed for all kinds of animals
having about the equivalent value of
| Npih iOl IdttlCt hOIS6S anu swine. III
| is used, technically, in the manu-
facture of yeast, alcohol, etc. The
product, being partially cooked, is
not suitable for the manufacture of
starch. One of the large manufactur-
ers of machinery is now trying out a
process for making a material that
will be suitable for making into fin
ished starch.
1t appears that this industry may
be applicable to the United States, es-
pecially where the question of freight
is one of Importance. for. as seen
above, the weight of product is re-
duced to one-fourth. 1t should en-
able our Western states to utilize the
advantages they have for potato
growing. both as a money crop and
as cultivated crop in the rotation
to prepare the land for wheat and
other grains. Furthermore, the ma
chimes could be used for drying sugar
beet pulp, beet leaves and other sim
liar products, as it is in this way the
German beet sugar factories conserve
their pulp. mixing 1t with a small
quantity of molasses for stock feed.
a part of which is exported to the
United States.