IMPROVEMENTS IN APPARATUS FOR DRYING OR DESICCATING SUBSTANCES BY MEANS OF HEATED AIR
Year: 1880

page_text: LETTERS PATENT to Charles Denton Abel, of No. 28, Southampton
Buildings, Chancery Lane, in the County of Middlesex, for an Invention
of "IMPROVEMENTS IN APPARATUS FOR DRYING OR DESICCATING SUBSTANCES
BY MEANS OF HEATED AIR." A communication from abroad by Eugen
Langen, of Cologne, in the German Empire.
j
PROVISIONAL SPECIFICATION left by the said Charles Denton Abel at the
Office of the Commissioners of Patents, on the 6th November 1880.
CHARLES DENTON ABEL, of No. 28, Southampton Buildings, Chancery Lane, in
the County of Middlesex. "IMPROVEMENTS IN APPARATUS FOR DRYING OR
DESICCATING SUBSTANCES BY MEANS OF HEATED AIR." [A communication from
abroad by Eugen Langen, of Cologne, in the German Empire.]
According to the present Invention the drying or desiccating of substances is
effected by causing the same to travel firstly through a passage, flue, or chamber,
through which a current of heated air is made to pass in the opposite direction,
and then through a passage, flue, or chamber through which a current of cold air,
serving subsequently to supply the current of heated air, is made to pass in the
opposite direction, so that the substances first have the moisture evaporated from
them by the action of the heated air and are then cooled by the application of the
cold air, which at the same time takes up and thus utilises the heat on its way to
the heating apparatus.
The construction of the apparatus for carrying out the above described mode of
operating is according to one arrangement as follows:-A vertical chamber is
divided by hollow vertical partitions into three compartments, of which the middle
one is double the width of the two outer ones. In these compartments are two sets
of horizontal trays, cages, or receptacles attached at each end to vertical endless
bands, chains, or cords passing over pullies at the upper and lower ends, and
receiving motion therefrom in such a manner that the trays of each set, which are
charged at top with the substance to be dried (such as slabs of sugar), pass down-
wards side by side through the middle compartment and then pass separately up
through one of the side compartments. In the lower part of the chamber the
middle compartment communicates with the two outer ones by means of openings
[Price 6d1

page_text: in the beforementioned partitions sufficiently large to allow the trays to pass from
the one compartment to the other, which openings are provided with sliding doors
that are rapidly opened and closed as each tray passes through, in order to keep
the compartments separated from each other except at the times when the trays
are passing, such movement of the trays only being made to take place periodically.
The trays are suspended by trunnions or pivots from the endless bands, so that as
they pass round the upper and lower loops they preserve their horizontal position.
The upper ends of the two side compartments are open to the atmosphere, while at
the lower ends they communicate by a passage with a fan or blower by means of
which the cold outer air is drawn into and down through the said compartments,
and is then propelled into the bottom of the middle compartment in which is
a heating apparatus consisting, by preference, of a number of steam beated tubes
with external radiating flanges or discs, so that air blown in by the fan becomes
rapidly heated thereby, and then passes up through the middle compartment,
evaporating the moisture from the substances contained in the trays descending
therein. At the upper end of the compartment the air passes through side holes
into the hollow partitions through which it is conducted to a chimney flue.
-
The periodical movement of the endless bands with their trays and the simul-
taneous opening and closing of the before mentioned slides is effected as follows:-
The shafts on which the upper pullies of the endless bands are fixed carry worm
wheels, both of which are in gear with one and the same worm rotated by a crank
handle and bevil gearing, so that by periodically moving the worm wheels through
a certain part of a revolution, a tray with its dried contents is drawn up out of
each side compartment and two trays charged with fresh substance to be dried are
made at the same time to descend into the middle compartment. During the time
that the trays are stationary, those that have been raised from the side com-
partments have the dried substance removed from them and are charged with fresh
moist substance.
In gear with the worm wheels are pinions of such a diameter that at each before
mentioned part of the revolution of the worm wheels they perform a complete
revolution; the axes of these pinions carry cams which act upon levers connected
by rods to other levers, pivotted at one end and connected at the other ends by
rods or bands to the said slides closing the openings in the partitions, so that at
each revolution of the pinions the cams actuate the levers so as to first raise and
then lower the slides again, the levers being so proportioned that the small throw
of the cams produces a considerably greater and rapid up and down motion of the
slides,
In applying the before described apparatus to the drying of substances in the
form of flat cakes or slabs, these are arranged in upright positions in the trays with
sufficient space intervening between each two slabs for the passage of the air
current between them, this position of the slabs being maintained by any suitable
means, such as by providing the trays with distance pieces fitting between the
slabs, or by placing between these loose corrugate, ribbed, or buckled plates, leaving
channels for the passage of the air.
Although in the above described apparatus two sets of travelling trays have been
spoken of, it will be evident that the same mode of operating may be carried out
with only one or more than two sets of such trays.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Charles Denton Abel in the Great Seal Patent Office on the
5th May 1881.
CHARLES DENTON ABEL, of No. 28, Southampton Buildings, Chancery Lane, in
the County of Middlesex. "IMPROVEMENTS IN APPARATUS FOR DRYING OR
DESICCATING SUBSTANCES BY MEANS OF HEATED AIR." A communication from
abroad by Eugen Langen, of Cologne, in the German Empire.
According to the present Invention the drying or desiccating of substances is
effected by causing the same to travel firstly through a passage, flue, or chamber
through which a current of heated air is made to pass in the opposite direction, and
then through a passage, flue, or chamber through which a current of cold air, serving
subsequently to supply the current of heated air, is made to pass in the opposite
direction, so that the substances first have the moisture evaporated from them by
the action of the heated air, and are then cooled by the application of the cold air,
which at the same time takes up and thus utilises the heat on its way to the
heating apparatus.
The construction of the apparatus for carrying out the above described_mode of
operating, which is employed by preference, is shewn on the accompanying Drawing,
in which Fig. 1 shews a longitudinal section of the appartus, and Fig. 2 a transverse
section of the same on line XXX., Fig. 1. A vertical chamber A is divided at the
upper part by the hollow partitions B, B, into three compartments C, C¹, C¹, of
which the middle one C is double the width of the two outer ones C¹. In these
compartments are two sets of travelling trays, cages, or receptacles D, D, connected
at each end to travelling endless steel bands, chains, or wire ropes E, E, stretched
over pullies or drums F, F¹, at top and bottom, and receiving motion from the
upper ones in such manner that the trays D of each set, which are charged at the
top of the chamber A with the substance to be dried (such as slabs of sugar) first
descend side by side through the middle compartment C, and then pass below the
partitions B separately into each of the side compartiments C¹ in which they ascend
again. The space in the chamber A below the partitions B, B, is also divided into
three compartments by other partitions G, G, and by slides H, H, which latter are
rapidly opened and closed as each pair of trays pass from the middle to the outer
compartments, in order to keep the compartments separated from each other at all
times except when the trays are passing, such movement of the trays being made
to take place periodically. The trays are suspended by trunnions or pivots D' from
blocks or bearings fixed on the endless bands E, so that as they pass round the pullies
F, F, at top and bottom they swing on such trunnions so as to preserve their
horizontal position. The upper ends of the two side compartments C, C¹, are open
to the atmosphere, while at the lower ends they communicate with passages I, I,
leading to a fan or blower by means of which the cold outer air is drawn into and
down through the said compartments, and which propels such air through the
opening K into the bottom of the middle compartment, in which is placed a heating
apparatus, consisting by preference of a number of steam heated tubes L, L,
provided externally with radiating plates L¹ by which a very extended heating
surface is presented to the incoming current of air, thus effectually heating this
before it ascends in the central compartment C: At the top of this compartment
side openings B' are formed in the hollow partitions B, through which the hot air
escapes into these partitions which conduct it to a transverse chamber M at one
end communicating with a chimney flue N. The periodical movement of the
endless bands with their trays and the simultaneous opening and closing of the
before mentioned slides H, H, is effected as follows:-The shafts O, O, of the upper
pullies F, F, carry worm wheels P, P, both of which are in gear with a worm P¹,

page_text: rotated by means of a crank handle P2, and bevil gearing P³, so that on periodically
rotating the worm P¹ the pullies will be turned through a portion of a revolution in
contrary directions, whereby one of the trays will be raised out of each of the side
compartments C, C¹, while at the same time two of the trays will descend into the
middle compartment. In gear with the worm wheels are pinions Q, Q, of such a
diameter that at each before mentioned part of a revolution of the worm wheels
they perform a complete revolution. The axes of these pinions carry cams Q',
which act upon rollers R' on levers R pivotted at R2, and connected by rods R³ to
other levers S enclosed in a transverse casing B2 connecting the ends of the hollow
partitions B. These levers are pivotted at S', and to their free ends are connected
steel bands, ropes, or chains S2, passing under guide pullies T, T, and over other
pullies T, T¹, inside the partitions B, B, and after descending in these they are
connected respectively to each end of the slides H, H, which work in guides at their
ends and pass with their upper side through slits in the partitions. Thus it will be
seen that at each part revolution of the pullies or drums F the cams Q¹ will cause
the levers R and S to raise and lower the slides, so as to allow of the passage of one
The
of the trays from each of the compartments C₁ into the compartment C.
levers are so proportioned that the small throw of the cams will produce a
considerable and rapid up and down motion of the levers S, and consequently of the
slides H, which in rising pass into the hollow partitions. The lower edges of the
slides, when closed, dip into troughs U carried by brackets U¹ and filled with sand,
felt, or other suitable material for forming a tight joint, thus effectually cutting off
the communication between the compartments.
The mode of operating with the apparatus for effecting the drying of the
substances, which I will assume to be slabs of sugar, is as follows:-I will assume
that all the trays D are charged with these slabs, which are placed on edge therein
with sufficient space between them for the free passage of the air, and that the
slabs in the top trays in the compartments C₁are dried and ready for removal,
while fresh moist slabs are contained in the toy trays in the compartment C. The
trays immediately above the compartment C having been charged with moist slabs,
the pullies or drums F are caused to perform a part revolution, whereby the said
trays are lowered one step into the compartment C, while at the same time a tray
will have passed at bottom from the compartment C into each of the com-
partments C, and the trays with dried slabs will have been raised out of these
compartments at top. While these trays are having the slabs removed from
them and are being recharged with moist slabs, the cold air drawn down the
compartments C₁ by the action of the fan, takes up the heat and remaining
moisture from the slabs in these compartments, and at the same time the hot air
passing up through the compartment C will evaporate the moisture from the slabs
contained therein, escaping at top to the chimney flue as before described. After
a certain interval of time which may conveniently be made to correspond with
the time occupied in unloading the dried slabs from the top trays and re-loading
them, the pullies F are again turned so as to raise another pair of trays out of the
compartments C¹ and lower another pair into the compartment C, and so on, the
operation of drying being thus a continuous one. By arranging the trays to travel
in the contrary direction to that of the air currents, the most perfect drying action
will be obtained, as by it the coldest and driest air is brought in contact with the
coolest and driest slabs, and the hottest air is brought in contact with slabs that
have already been heated and dried to a considerable extent.
Although I have described this Invention as applied to two sets of travelling
trays in combination, this being the most convenient arrangement, yet it will be
readily understood that only one set of trays may be used, or more than two sets
may be arranged in combination.
In applying this apparatus to the drying of substances in the form of slabs, such
as slabs of sugar produced by processes for which previous Letters Patent have
been granted to me (as a communication from the said Eugen Langen), I prefer to
support such slabs in upright positions side by side in the trays, with sufficient

page_text: spaces intervening between them for the free passage of the air currents. To support
them in this position, the trays D may either be constructed with racks into which
the slabs are placed, or I insert loose, grooved, ribbed, or buckled plates, such as
are shewn at Figs. 3 and 4 between the slabs, or other suitable means may be
employed for this purpose which, while affording the necessary support to the slabs,
allow of the passage of the air currents in contact therewith.
Having thus described the nature of this Invention, and in what manner the
same is to be performed, as communicated to me by my foreign correspondent,
I claim,
First. The construction of apparatus for drying or desiccating substances, wherein
such substances are caused to travel first through passages or chambers through
which currents of hot air are passing in the opposite direction, and are then caused
to travel through passages or chambers through which currents of cold air are
passing in the opposite direction, such cold air being afterwards made to furnish
the said supply of hot air, substantially as herein described.
Second. The construction of apparatus for drying or desiccating substances,
wherein a set of trays containing the substance to be dried is suspended from
travelling bands or chains inside two separate passages or chambers, the trays being
made to descend in the one passage in which hot air is made to ascend, and to
ascend in the other in which cold air is made to descend, the two passages being
made to communicate with each other at bottom through openings that are closed
by slides, except when the trays are passing through them from the one passage
into the other, substantially as herein described.
Third. In apparatus for drying or desiccating substances, the combination of
the compartments C, C', travelling trays D, endless bands E, slides H, H, and
heating apparatus L, supplied with air by a fan or blower that draws air from
the compartments C¹, all arranged and operating substantially as herein described.
Fourth. In apparatus for drying or desiccating substances, the combination of
the endless bands E, trays D, pullies F, worm wheels P, worm P', pinions Q
cams Q', and levers R, S, operating slides H, so as to open and close these each
time that the trays are moved a step, substantially as herein described.
Fifth. In apparatus for drying or desiccating substances, the chamber A divided
by hollow partitions B, slides H, and partitions G, into three compartments C, C¹, C¹,
of which C contains the heating apparatus L supplied with air from the com-
partments C¹, C, and has side opening B' at top through which the air escapes to
a chimney flue, substantially as and for the purposes berein set forth.
Sixth. In apparatus for drying or desiccating slabs of sugar or other material,
the method of supporting the slabs in vertical positions in the travelling trays D
by the interposition of plates or distance pieces, leaving channels or spaces for the
passage of the air currents in contact with the slabs, substantially as herein
described.
In witness whereof, I, the said Charles Denton Abel, have hereunto set my
hand and seal, this Fifth day of May, in the year of our Lord One thousand
CHA³. D. ABEL. (L.S.)