IMPROVEMENTS IN APPARATUS FOR DRYING STARCH AND OTHER MOIST SUBSTANCES OF A PULVERULENT, MEALY, GRANULAR, OR SIMILAR CHARACTER.
Year: 1879

page_text: LETTERS PATENT to Alexander McDiarmid, Manager to Messieurs James
Anderson and Company, of Glasgow, in the County of Lanark, North Britain,
for the Invention of "IMPROVEMENTS IN APPARATUS FOR DRYING STARCH AND
OTHER MOIST SUBSTANCES OF A PULVERULENT, MEALY, GRANULAR, OR SIMILAR
CHARACTER.
"
Sealed the 27th February 1880, and dated the 30th August 1879.
PROVISIONAL SPECIFICATION left by the said Alexander McDiarmid at
the Office of the Commissioners of Patents on the 30th August 1879.
ALEXANDER MCDIARMID, Manager to Messieurs James Anderson and Company,
of Glasgow, in the County of Lanark, North Britain: "IMPROVEMENTS IN
APPARATUS FOR DRYING STARCH AND OTHER MOIST SUBSTANCES OF A PULVERU-
LENT, MEALY, GRANULAR, OR SIMILAR CHARACTER."
This Invention has for its object the drying of starch and other moist substances
of a pulverulent, mealy, granular, or similar character, in an improved and
expeditious manner.
.
The improved apparatus consists of a semi-cylindrical trough or channel placed
in a horizontal or slightly inclined position, and having working within or upon it
a screw or series of screw or oblique blades upon a longitudinal shaft, which is
turned to cause the screw or blades to agitate and move the substances gradually
along the trough. The trough is made of metal and hollow, or in other words,.
with an outer shell enclosing a jacket space into which steam is admitted for the
purpose of supplying the heat for the drying operation. It is an important feature
of the arrangement that the trough is uncovered, so that the vapors may escape
freely from all parts, and so long as this feature is retained the trough may in shape'
correspond to less or more than the half circle, as may be found convenient in
practice.
In cases in which a considerable length of trough is required, such length may
be made up of two or more short lengths, the substances operated on being guided
by ducts or shutes from one to the other in succession. In a convenient modi-
fication there are three lengths, the second and third being under or lower than
the first, and the substances are moved along the second in the opposite direction
to that of their movement in the first, whilst their movement is again reversed in'
the third, so that they are finally delivered at the opposite end of the apparatus
from that at which they were entered.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alexander McDiarmid in the Great Seal Patent Office on the 27th
February 1880.
ALEXANDER MCDIARMID, Manager to Messieurs James Anderson and Company,
of Glasgow, in the County of Lanark, North Britain. "IMPROVEMENTS IN
APPARATUS FOR DRYING STARCH AND OTHER MOIST SUBSTANCES OF A PULVERU-
LANT, MEALY, GRANULAR, OR SIMILAR CHARACTER."
My said Invention has for its object the drying of starch and other moist
substances of a pulverulent, mealy, granular, or similar character, in an improved
and expeditious manner.
My improved apparatus consists of a trough or channel placed in a horizontal or
slightly inclined position, and having working within or upon it a screw or series
of screw or oblique blades upon a longitudinal shaft, which is turned to cause the
screw or blades to agitate and move the substances gradually along the trough.
Heat is applied to the trough by means of a steam or hot-air jacket; and it is an
important feature of my improved arrangement that the trough is uncovered so
that the vapors may escape freely from all parts.
In cases in which a considerable length of trough is required, such length may
be made up of two or more short lengths, the substances operated on being guided
by ducts or shutes from one to the other in succession.
And in order that my said Invention and the manner of performing the same
may be properly understood, I hereunto append a Sheet of explanatory Drawings,
to be hereinafter referred to, and representing a convenient modification of my
improved apparatus. In these Drawings the same reference numerals are used to
mark the same or like parts wherever they are repeated.
Figure 1 on the accompanying Sheet of Drawings is a transverse vertical
section of the apparatus, and Figure 2 is a side elevation partly in longitudinal
vertical section, and as with portions broken away to reduce the length of the
Figure. In this modification there are three troughs 3, 4, 5, placed one above the
other, and each about 30 feet long. Each trough is formed with two shells 6, 7,
represented as of castiron, but which may be of wrought iron or other suitable
metal if preferred. Steam is admitted to the jacket spaces between the two shells
6, 7, by branch steam pipes 8 having regulating valves; and outlet branches 9 are
fitted to the jacket spaces, and communicate with a discharge pipe 10, having a
__ small pipe 11 at the bottom by which water due to condensation can pass off.
The troughs 3, 4, 5, are placed between wooden (or it might be metal) uprights 12,
and rest on transverse rollers 13 carried in bearings on the uprights 12, the rollers
allowing the troughs to be acted on by changes of temperature without the
strains that might arise if they were rigidly fixed.
The lower part of the interior of each trough 3, 4, 5, is by preference made semi-
cylindrical or to correspond to rather less or more of a semicircle, but always with
its top or upper part uncovered or open, so that the vapors rising from the moist
materials that are being dried may escape freely from all parts. Within each
trough there is a longitudinal shaft 14 carried in bearings 15, 16, and on this
shaft screw or oblique blades 17 are fixed for the purpose of agitating the starch
or other substances and gradually moving them along the troughs. The blades 17
are by preference made adjustable so that they can be set more or less obliquely
as may be found desirable in practice. The shafts 14 are geared together by spur-
wheels 18 at one end, and the uppermost spur-wheel has in gear with it a pinion 19
on a shaft having on it a pulley 20 for a driving belt, the requisite motion may
however be communicated in any other convenient way.
The starch or other moist substance to be dried is supplied by means of a spout
or duct 21 to one end of the top trough 3, and is gradually moved along that

page_text: trough by the oblique blades 17 at length falling out at the other end where it is
led by a spout or duct 22 into the second trough 4. The substance travels along
the second trough 4 in the opposite direction, and falls from its end by a duct 23
into the third trough 5, along which last it travels in the same direction as along
the first, being finally delivered in a dried state at the end 24. The dried
substance inay be delivered into any convenient receptacle, there is however shown
in the Drawing the trunk 25 of an elevator, and a duct is indicated by dotted
lines at 26 for leading the substance into the bottom of such elevator.
The heat may be applied by means of heated air, such air being either heated in
separate apparatus and passed through the jacket space, or being admitted to the
inner compartment of a double jacket and heated by steam admitted to an outer
compartment of the jacket. The shafts 14 may be made hollow, and the blades 17
also, and steam or hot air may be passed through them to assist the drying
operation.
Having thus particularly described my said Invention and the manner of per-
forming the same, I have to state that I do not restrict myself to the precise
details herein described or delineated, but that what I believe to be novel and
original and claim as the Invention secured to me by and in terms of the herein-
before in part recited Letters Patent is,-
1. The constructing of apparatus for drying starch and other moist substances of
a pulverulent, mealy, granular, or similar character, substantially in the improved
manner herein before described.
2. The employment of an open-topped trough heated by means of a steam or
hot-air jacket, and having the lower part of its interior of a segmental cylindrical
form, substantially in the manner and for the purposes hereinbefore described.
In witness whereof, I, the said Alexander McDiarmid, have hereunto set
any hand and seal, this Twenty-fifth day of February, in the year of our
Lord One thousand eight hundred and eighty.
Witness,
EDMUND HUNT,
Patent Agent,
Glasgow.
A. M'DIARMID. (L.S.)