Improvements in Stoves or Apparatus for Drying Skins, Malt, Phosphates, and Animal, Vegetable and Mineral Products.
Year: 1892

page_text: Date of Application, 26th May, 1892-Accepted, 8th Oct., 1892
COMPLETE SPECIFICATION.
Improvements in Stoves or Apparatus for Drying Skins, Malt,
Phosphates, and Animal, Vegetable and Mineral Products.
I, AUGUST RÜBENKAMP, of Dortmund, in the German Empire, Engineer, do
hereby declare the nature of this invention and in what manner the same is to
be performed to be particularly described and ascertained in and by the following
statement :-
This invention relates to apparatus adapted for use in drying various animal,
vegetable and mineral products, both in a raw and in a manufactured or partly-
manufactured state; as, for example, skins, offal, vegetables, malt, raw ceramic
ware and phosphates; the objects of the invention being, first, to avoid the great
loss of heat arising when the products of combustion and the hot drying air are
allowed to escape directly into the atmosphere, and secondly, to allow of a gradual
warming and cooling of the goods under treatment.
In the accompanying drawings,
Fig. 1 is a transverse vertical section of drying apparatus constructed according
to the present invention; the section being taken on the lines 7, 8 and 9, 10 (Fig. 7);
Fig. 2 being a similar view on the line 11, 12 (Fig. 7). Fig. 3 is a front elevation.
Fig. 4 is a horizontal section on the line 1, 2 (Fig. 7); Figs. 5 and 6 being similar
views on the lines 3, 4 and 5, 6 (Fig. 7) respectively. Fig. 7 is a vertical longitu-
dinal section on the lines 13, 14 and 14, 15 (Fig. 4).
The heated air which serves to dry the goods, after passing through the drying
chamber, is brought back to the closed furnace, where it serves to effect combustion
of the fuel. The products of combustion, and the air which passes through the
drying chamber and the various tubes and channels for the purpose of heating
the apparatus, are not conducted directly to the chimney, but are first passed
through the heating tubes and channels of a second apparatus in order to bring
the same into a state ready for the commencement of the drying process.
A separate furnace may be employed for each apparatus, or several apparatus
may be connected to one furnace. In the latter case, it is necessary to use a special
system of pipes with dampers or stop-valves, so that the drying and the cooling of
the independent chambers can be conveniently and exactly regulated.
The hot gases pass from the closed furnace a (Fig. 7), which is fed with fuel
through the openings 6, over the bridge c, and through the channels & beneath the
floor; thus heating the drying chamber e, in which the goods to be dried are placed
through the doors f (Fig. 2). The lift-valve g' being open, the gases and smoke
flow past that valve and are drawn off through the channel h¹ (Fig. 4) into the
chimney or exhauster, as the case may be.
The air for drying the goods passes through the straight pipes or channels i
(Fig. 7), which are made of metal, fire-clay or brickwork. They may, however,
be spiral instead of straight. They are arranged in the furnace-chamber over the
closed hearth a, and extend to the drying chamber e, in which the air becomes
saturated with moisture from the goods under treatment. The saturated air is led
back through the pipes k, land m to outlets beneath the fire-bars of the closed
hearth a.
If the second apparatus contain goods requiring to be dried, the lift-valve g' is
closed and the lift-valve g' opened, so that the hot gases are no longer drawn off
directly through the channel ¹ into the chimney or exhauster, but pass through
the channel 2 to inlets m beneath the furnace of the second apparatus, and thence
into the channels & beneath the floor thereof. When the gases have given up their
heat, they are drawn off through the channel of the second apparatus by the
chimney or exhauster. While the second apparatus is being thus warmed, aqueous
vapour rises from the goods it contains, and escapes through the openings n, which

page_text: are furnished with dampers (Figs. 4 and 7); the tubes of the second apparatus,
through which the air enters, being however closed, as otherwise the cold air
would force its way in and cool the apparatus too-much.
When the required temperature and degree of dryness have been obtained in
the first apparatus, the lift-valve g is also closed; the fire on the closed hearth a
becoming extinguished. The closed hearth of the second apparatus is thereupon
lighted and gradually fed with fuel; the drying process being then carried out as
in the first apparatus.
In order to gradually cool the goods in the first apparatus, cold air is allowed to
enter the drying chamber from the atmosphere by way of the tubes i, such air
passing through the drying chamber, the tubes k, the system of pipes 1, the
'openings m, the fire-bars a, and the chaunels d. The valve g' being open, the air
is then sucked through the channel into the chimney or exbauster, or else it goes
past the valve 92 and along the channel into the next apparatus.
The preliminary warming, drying and cooling may be carried out in a series of
apparatus such as described. The apparatus may be arranged in a circle, so that,
when the process is finished in the last, it can be commenced in the first. Or, the
process can be repeated in an inverse order, the last drying chamber but one being
refilled and then warmed with hot gases from the last.
In the case of drying apparatus arranged in series, the hot gases for heating can
be derived from one central furnace. By such arrangement, a more gradual
warming and cooling of the whole series of chambers can be effected, and the
course of the drying process in the several sections can be accurately regulated.
The air heated by the central furnace may be conveyed to a special receptacle,
whence it can be withdrawn as required through a system of pipes, provided with
dampers and valves, to the various apparatus.
Where necessary, a rotary drum or a suitable mechanical arrangement for turning
over the goods, or for moving the same slowly from one end to the other of the
drying chamber, may be employed.
One great advantage incidental to the use of the improved apparatus is that any
noxious gases given off by the goods under treatment are led to the furnace and
burnt such gases being thus rendered innocuous.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, I claim :-
1. For drying raw or prepared goods, the herein-described apparatus in which
the air for drying the goods is drawn through the apparatus by means of a chimney
or exhauster, such air traversing a system of pipes or channels i arranged in a
closed furnace, and, after issuing from the drying chamber e, being conducted to
the furnace to effect the combustion of the fuel therein.
2. In drying apparatus such as herein referred to, conveying the hot gases and
the hot air issuing from one apparatus into another or several other apparatus,
substantially as and for the purposes set forth.
3. In a series of drying apparatus such as herein referred to, the employment of
a central closed furnace for the several apparatus and of a corresponding system
of pipes provided with dampers and valves for the purpose of conveying the hot
gases and the warm drying air respectively into the passages beneath the floors and
into the chambers of the several divisions of the apparatus, substantially as and
for the purposes set forth.
4. In a series of drying apparatus of the kind herein referred to, the employment
of a special receptacle for the hot air, such air being withdrawn from the receptacle
as required for the several apparatus, substantially as described.
Dated the 25th dox of Mor 1906
G. G. M. HARDINGHAM,
191, Fleet Street, London, E.C., Chartered Patent Agent.