A UNIVERSAL DRUM SCREEN FOR SORTING MINERALS, EARTHS, AND CHEMICAL PRODUCTS, AND THE LIKE
Year: 1876

page_text: PROVISIONAL SPECIFICATION left by Frank Wirth at the Office of the Com-
missioners of Patents on the 9th Juno 1876. A communication from abroad
by Martin Neuerburg, residing at Kalk, near Cologne, in the Empire of Germany.
FRANK WIRTH, of the Firm of Wirth and Company, Patent Agency, of Frankfort-
on-the-Main, in the Empire of Germany. "A UNIVERSAL DRUM SCREEN FOR
SORTING MINERALS, EARTHS, AND CHEMICAL PRODUCTS, AND THE LIKE" A com-
munication.
kk
For dressing ores and coals, and for utilizing reduced minerals and chemicals, it
is sometimes necessary to separate the material into several sizes of grains. For
this purpose hand sieves and sieves of other construction have been used but more
recently only rotating drum sieves have been employed. These drum sieves have
had several forms and arrangements and their operation has been found satisfactory
for assorting a few sizes of grains but not for assorting all sizes of grains.
In order to obtain the desired result several sieves were employed, for instance,
in a preparatory drum coarse grains, middle grains, and fine grains were pre-
viously assorted, which grains were then thrown into lower drum sieves for
obtaining in these sieves the several sizes of grains.
A further improvement was made by arranging several drum sieves one above
the other, the number of these sieves corresponding with the number of sizes to be
assorted. By, this arrangement it was possible to separate first the coarse grains and
successively the finer grains which was not possible by the aforesaid arrangements.
The advantages arising from this arrangement were as follows, namely:-First,
there was no more need to bring the whole mass of the material over the finest
sieves, which are the most expensive, and the replacement or repair of which were
therefor the more costly. In consequence of the great friction caused by the whole
mass being brought to these fine sieves the latter were the most subject to wear,
and had to be the most frequently replaced.
Second. The greatest quantity was brought first over the widest sieves, which at
the same time are the most durable and less costly, in consequence the wear and
tear of the whole arrangement was reduced to a minimum.
Third. Every sieve could be made of dimensions exactly corresponding with the
quantity of material to be separated, and consequently the cost of construction was
economized.
But this arrangement had the great disadvantage that a great height or fall was
wanted, which heights must in most cases be attained by elevating wheels, eleva-

page_text: tors, lifting machines, and the like, whereby the whole arrangement became com-
plicated and costly.
Many experiments were made to avoid these disadvantages without dispensing
with the advantages proceeding from separating the coarse grains from the finer
sizes, but without any satisfactory result. A solution of this problem is effected by
the construction of my universal assorting drum sieve.
This sieve offers all of the above advantages, namely:-First, the separation of
the grains commences with the coarse grains and proceeds to the finer sizes; second,
every sieve may have the proper size; third, a slight height or fall only is required.
This apparatus has a shaft rotating in suitable plummer blocks, on this shaft are
fixed cross bars, the number of which corresponds with the number of sizes of
grains to be obtained, these cross bars are united by sheet iron sieves, the said
sieves are partly surrounded by sheet iron, and partly by another sieve, the aper-
tures of which are finer than those of the first sieves.
The mass to be assorted is brought into the drum through a funnel, and as the
first sieve has the widest openings all finer grains fall through this sieve on the
mantle, by the rotation of the sieve the material to be assorted moves to the cross
bars where the coarse grain is stopped and falls through the tubes and the funnel
to the magazine.
The grain that falls through the sieve is caught by shovels and brought to the
second section of the drum sieve, here the above operation is repeated, the coarsest
grains come to the cross bars and fall through the tubes and funnel to the maga-
zine. The grains that fall through the sieve are by the said shovels brought to the
third section. It is obvious that the number of such sections may be augmented
without departing from the principle of my Invention.
From the last section the coarest grains fall through the funnel to the magazine,
the finer grains to the finer sieve, which arrests those of a further size that fall
through the funnel into the magazine, whilst the finest materials fall through the
sieve to the funnel and therefrom to the magazine. If this series of drum sieves is
of a great length the same must be supported by bearing rollers.