Improvements in Apparatus for Drying Earthy, Disintegrated, or similar Materials.
Year: 1889

page_text: Date of Application, 14th Aug., 1889
Complete Specification Left, 5th May, 1890-Accepted, 28th June, 1890
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Drying Earthy, Disintegrated, or
similar Materials.
I, VERNER FREDERIK LAESSOE SMIDTH, of 29 Vestergade, Copenhagen, in the
Kingdom of Denmark, Engineer, do hereby declare the nature of this invention to
be as follows:-
My invention relates to an apparatus for drying earthy, disintegrated, or similar
materials in large quantities by the application of hot air. My apparatus has the
form of a shaft, on the upper part of which I introduce the material, so that it shall
slowly descend by its own weight.
I place the shaft on a foundation of stono or brickwork by means of supports
rivetted to the shell of the shaft in such a manner as to leave a space all round
between the shell and the brickwork, through which the dried material may escape.
I introduce the hot air through a channel arranged through the centre of the
before mentioned brickwork and continued into the lower part of the shaft. On the
top of this channel I arrange a series of truncated conical rings, the uppermost of
which is closed by a disc.
By this arrangement 1 prevent the material to be dried entering the hot air channel,
though the hot air can enter freely into the material.
In order to introduce the hot air I arrange a blowing engine, fan, or other
suitable apparatus to produce the necessary pressure for forcing the hot air through
the material to be dried, after which it escapes through the top of the shaft. In
most cases, however, I prefer to arrange an exhauster on the top of the shaft by
which I suck the hot air through the material. This arrangement has the further
advantage of utilizing the heat given from the dried material to the outside air at
the foot of the shaft which would otherwise be wasted by sucking such heated air
into and through the shaft by the open space which serves for the escapo of the dried
material.
In order to allow of regulating the height of the open space at the bottom of the
shaft, I surround the lower end of the shell with a conical ring of sheet metal which
may be lowered or raised, so that the aperture becomes smaller or larger according
to requirement.
For feeding the material into the shaft I arrange on the upper part of the shaft a
funnel in an oblique direction which I carry through the shell and then downward
in the axis of the same, so that the delivery mouth of the funnel shall be some distance
above the cover of the uppermost conical ring. The position of the delivery mouth
of this funnel determines the height of the material in the shaft, and it is adjustable
by a sleeve sliding on the delivery end of the funnel.
In order to continuously carry away the dried material, I surround the foundation
of brickwork with a ring resting on rollers and supplied with receptacles for the
dried material. Over these receptacles I arrange scrapers on the ring, which slide
obliquely over the foundation. The ring with receptacles and scrapers is slowly
rotated, the rotation being regulated so that the scrapers fill the receptacles during
one revolution of the ring. Un the outer side of each receptacle 1 arrange a flap
closed by a counterweight, and on the foundation is placed a tappet which is formed
so as to lift the counterweight of the flap as soon as the receptacle arrives near it in

page_text: the course of its travel.
worm or other
When the counterweight is thus lifted, the closing flap of
the receptacle is opened and the contents of the latter fall into a
transporting device which carries it to any desired place.
Dated the 14th day of August 1889.
FELL & WILDING,
Agents for the Applicant.
Improvements in Apparatus for Drying Earthy, Disintegrated, or
similar Materials.
1. VERNER FREDERIK LAESSOE SMIDTH, of 29 Westergade, Copenhagen, in the
Kinglom of Denmark Engineer do hereby declare the nature of this invention
and the manner in which the same is to be performed to be particularly described, and
ascertained in and by the following statement:
My invention relates to an apparatus for drying earthy disintegrated or similar
materials in large quantities by the application of hot air.
In order that my invention may be the better understood, I now proceed to
describe the same in relation to the drawings hereunto annexed and to the letters
and figures marked thereon.
Figure 1, Sheet 1, is a vertical section of my apparatus.
Figure 1, Sheet 1 is a detail view of a striking crow bar.
Figure 2, Sheet II and figure 3, Sheet III are two horizontal sections of my
apparatus, and
Figure 4, Sheet IV. is a modification of the same.
My apparatus has the form of a round shaft C. in the interior of which is
arranged a dome C₁, covering the lower part of the shaft-Through the foundation
of the shaft enter one or more hot air channels A. ascending in the centre of the
shaft and ending in a nozzle formed by a series of truncated rings m. On the top of
the dome is arranged a cylinder C" of sheet metal, through the cover of which
reaches a funnel e. into the dome C¹.
The material is introduced into the funnel e. from which it sinks into the shaft
where it presses against the surrounding wall of the latter on account of the conical
form of the outside of the cover B. of the series of truncated rings, finally leaving
the shaft through a series of holes, v, arranged at one level around the lower edge of
the shaft. In order to prevent the entrance of outside air through the funnel e, tho
latter is always kept completely filled with the material.
An exhauster g. arranged on the upper part of the shaft C, on Figures 1 and 3
forces the hot air upwards through the descending material and sucks at the samo
time outside air through the exit holes v, which absorbs the otherwise waste heat of
the escaping dried material and utilizes the same in drying the higher zones of the
material.
The hot air leaving between the truncated rings m, endeavours to pass upwards
to the top of the shaft through the passages offering the least resistance and the
same is the case with the air sucked in through the exit holes for the dried material.
If this tendency of the air were not provided for, two air currents would be formed
ascending approximately vertical in the shaft viz. in a hot air current rising near the
conical cover B. and parlled to it a current of cold air ascending on inner side of the
wall of the shaft. The hot air would therefore penetrate only part of the material in
the shaft and the cold air from the exit holes would during the greater part of

page_text: its passage come into contact with material of low temperature and would absorb
heat only shortly before escape through the exhaust channel which heat would thus
be wasted.
In order to prevent the formation of the before mentioned currents, I have designed
the following arrangement.
On the inner side of the wall I form projections k rising radially towards the
centre of the shaft (Figures 1 and 2) on the edges or steps of which rest rings of
sheet metal, the upper rim of the lower of these rings, L, receding from the inner
side of the wall of the shaft and the upper rim of the upper ring P. coming into close
contact with such inner side, see Figure 1.
In this way I form an annular channel, between the ring L and the wall of the
shaft protected against the descending material and connected at its upper part to the
interior of the shaft by an annular opening ¹ formed between the upper end of
the ring L. and the lower rim of the ring P. This empty annular channel i.
offering no resistance to the passage of hot air from the nozzle rings, attracts the
same radially through the material and allows it to escape through the annular
opening to pass again through the material upwards to the exhauster. The hot
air is therefore compelled to penetrate all parts of the descending material.
The outside air sucked through the holes thus comes into contact with hot
material only, absorbs the heat of the same and is led by and with the hot air into
and through the channel i to enter through the channel the colder regions of the
material and to give off its heat before escape through the exhauster.
The mixture of air escaping from the shaft enters the cylinder (connected to
the exhauster g by the channel e through which the air escapes.
The before described division of hot air and direction of the cold air current may
be effected by the modified devices shown in Figure 4 Sheet IV.
While in the former case I formed the nozzlo or series of truncated conical rings B
by bevelled annular plates thus obtaining horizontal or nearly horizontal air passages
in this case I form the same by hollow truncated cones forming air passages in an
oblique downward direction.
Further I form the rings L. & P. obliquely above one another so that the lower
ring L again recedes from the wall of the shaft while the upper ring P is in close
contact with the latter.
Thus I form in a modified manner the before mentioned empty channel i. and
the annular opening .
In order to continuously carry away the dried material, I surround the brickwork
foundation of the apparatus with a revolving ring D in Figures 1, 3 and 4 carried
on wheels r and supported by sideward guiding rollers s. This revolving ring Dis
supplied with receptacles p for the dried material. The outer longitudinal side of
each of these receptacles is enclosed by a flap under the pressure of a weight o.
Sidewards over these receptacles I arrange scrapers on the revolving ring to slide
obliquely over the rim of the foundation.
The ring D with the receptacles is revolved slowly by any convenient motive
power and the velocity of such travel and the position of the scrapers is regulated
so that the latter scrape sufficient material into the receptacles to fill them during
one travel around the apparatus.
When a receptacle las completed its travel around the apparatus its weight o
strikes against the oblique edge of a cross bar or tappet 7 situated sideward on
a standard q, Figure 1, and is gradually lifted by the same, thus opening the
closing flap of the receptacle. In consequence the contents of the latter are
discharged into a transporting worm or other convenient vehicle for transport to
any desired place.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion and the manner in which the same is to be performed I declare that what
I claim is
1. A drying apparatus in the form of a shaft in which the descending inaterial fed
from the top is dried by means of hot air introduced centrally from below and
penetrating the material partly in an ascending direction and acting under the
influence of an annular channel around the inner side of the wall of the shaft in a
horizontal direction and in addition by outside air sucked in by an exhauster through
the exit holes for the dried material at the foot of the apparatus and mixing with
and travelling in the same direction as the hot air.
2. In a drying apparatus as before described the arrangement of a revolving
ring D travelling around the foundation of the apparatus and having receptacles p. o.
receiving the dried material scraped into them during the travel of the ring and
feeding it into a suitable device for further transport after the automatic opening of
their closing flaps by the counter weights of the latter striking against the tappet
of a standard q.
11.1.
1
Ր
1000
FELL & WILDING,
Agents for the Applicant.