Year: 1888

page_text: This Specification was, upon the 12th day of November 1889, Amended under
Sections 18 to 21 of the Patents, Designs, and Trade Marks Act, 1883.
I, EMIL PASSBURG of Breslau in the Empire of Germany, Engineer do hereby
declare the nature of this invention and in what manner the same is to be per-
formed to be particularly described and ascertained in and by the following
statement:
This invention relates to vacuum drying apparatus and consists in certain improve-
ments 'therein. The improvements comprise firstly the arrangement. whereby a
considerable heating surface is displayed in a place as small as possible, secondly: a
drying cylinder with a heated feed device of particular construction and an arrange-
iment for retaining dust and particles carried off with the vapour from the damp
material, thirdly a device for utilizing the vapours derived in one apparatus to heat a
second and third apparatus (double or triple effect), fourthly novel hoppers for feeding
the material to be dried continually and regularly and for carrying off the, dried:
material without destroying the vacuum.
Referring to the accompanying drawings,
Fig. 1 is a vertical, longitudinal section of the improved apparatus.
Fig. 2 is a vertical cross section through the same..
Figs. 3 and 4 represent in longitudinal and cross; section a novel hopper for
disintegrating and feeding the material.
Figs. 5 and 6 are representations in which the chief apparatus is enclosed in walls
to be heated by the furnace gases.
.
•
Figs. 7 and 8 represent a modified hopper for continual feed.
Fig. 10 is a vertical longitudinal section showing a further modification therein.
Fig. 11 is a detail view thereof, and
Fig. 12 is a diagramatic representation of said detail.
Figs. 13 to 17 represent another form of continuous feed and exhaust. Figs. 13.
& 15 in longitudinal section and Figs. 14 and 16 in cross section. Fig. 17 repre-
sents a side view of a vacuum cylinder with the feed apparatus represented in
Figs. 13 to 16 added thereto.
Figs. 18 to 19 represent in side and front elevation a vacuum drying apparatus
into which the material is fed through a long curved tube with pistons for continuous
automatic feed.
Fig. 20 represents the same device with short conical hopper.
Fig. 21 represents the same device fed by a conically tapered screw.
14
↑ "

page_text: In Figs. 1 and 2, A is the feed hopper; B the cylinder for receiving the material
and S the horizontal transport barrel to be heated. The latter is closed at both ends
with covers with hollow cast cones or journals carried in the stuffing boxes of the end
covers of the cylinder B. On the barrel are the inclined hollow ridges t and also
bars (for cleaning the cylinder walls B of substances adhering). The diameter of
the barrel is as large as possible to magnify the heating surface and to cause the
material to be pressed on the heating surfaces by reason of the narrow space between
the barrel and cylinder B and thus enhance the effect of the same.
In this manner the material is forwarded from the hopper A through the cylinder B
into the main cylinder C where it will arrive already dried to a certain extent so
that it will not adhere to the heating pipes. The cylinder C is surrounded in the
known manner by a jacket and contains a rotary heating pipe b' of large diameter,
giving the necessary strength to the beating system and a number of smaller heating
pipes 6 all fastened steam tight in the walls e. The walls e and the steam covers Ď
vaulted to the inside and therefore of greater strength are riveted steam tight on
a U-shaped iron ring as shown. The journals cast on the steam covers D rotate in
the stuffing boxes of the end closing cover of the cylinder C and are hollow and
provided in the known manner with the stationary steam inlet pipe f and exhaust
pipe respectively. Of the steam covers Done possesses a baffle plate v distributing
the entering steam, the hot air etc.; the other carries a bucket tube i throwing out
on the turn of the drum the condensed water.
On the drum b' are also arranged lugs carrying short shovels distributing the
material as the drum revolves.
The vapour disengaged in the cylinder C is absorbed by the air pump leading into
the upper part of the cylinder B and the dust and particles carried up are held back
by the damp material in the cylinder C.
The upper drying cylinder B can be shut off hermetically from the lower drying
cylinder and the latter from the exhaust hopper F by valves g and g' in the known
manner so as not to interrupt the vacuum and drying when filling in C.
The space between C and A is measured so that if the valve g is closed F can be
cleared out while the drum S transports the whole contents of the hopper A into C.
It is also possible not only to dry materials in this apparatus but also to bake them
if necessary after drying for a certain time in a higher temperature.
Thus malt may be dried therein at first at about 30° Centigrade and in a high
vacuum and afterwards at a higher temperature.
The hopper (Figs. 3 and 4) is destined for such substances as bave to be pulverized,
broken, or torn so that the water may be driven out. In the hopper two hollow and
heated rollers i rotate in contrary direction. The steam enters through the tube e in
both rollers and the condensed water leaves at e¹ by bucket pipe 8. f and 1 are
counterpoised spades for cleaning the surface of the rollers. The rollers press and
grind the material and transfer it to the cylinder B.
In the arrangement shown in Figs 5 and 6 two drying cylinders C and Cl and two
heaters B and B the interior arrangement of which is the same as described with
reference to Figs. 1 and 2 fire gases or hot air being here used for heating.
The ventilator V drives air through a tube system i ii placed in the flue of a
furnace, the gases heating the tubes i. The air passes through the tube D and hollow
journals into the drums of the cylinders B and C and thence through tube D¹ into
the chimney S. The warming of the cylinders A and C, may be performed either by
a part of the hot air heated in i led thereto or by the gases from the furnace passed
around the cylinders.
The latter case is represented in the drawings. The gases pass through pipe E
within the walls enclosing the cylinders and leave the latter through pipe E' into the
chimney S.
In this arrangement the double and triple effect before mentioned is represented.
The cylinders B and C are connected with a small air pump giving a low vacuum.
The cylinders B' and C¹ with a larger air pump giving a higher vacuum.
If the material is fed in the manner beforedescribed, first vapours are disengaged

page_text: in B and C the temperature of which is high corresponding to the lower vacuum.
These vapours.are used for heating the cylinders B' and C¹.
They pass into the dome 6 (Figs. 5 and 6) and thence through pipes K, H, into
the interior heating drums of B₁ and C¹. The condensed water is taken up by
pipes m by means of the small air pump beforementioned.
With the smaller air pump are connected the heating drums of the cylinder, B¹
and C and through them the drying spaces of the cylinders B and C. (Fig. 6).
Whereas the drying spaces of the cylinders B' and Care connected by tube L
(Fig. 6) with the larger air pump. The different temperature in the cylinders Band B¹
or C and C is balanced by the difference of the vacuum so that the drying can take
place equally in both drying apparatus.
This system can also be expanded to three or more drying apparatus.
The system of using the vapours again for heating (double and triple effect) is
known but the special arrangement here shown is claimed as an invention. The
apparatus described works with periodical filling and clearing out and is well fitted for
watery and slowly drying materials,
On the other hand for materials with less water contents or such as are easily and
quickly dried as wet grain, peat &c. a continual feed and exhaust of the material
without destroying the vacuum is prefered.
For this purpose are the following devices.
Figs. 7 to 9 illustrate a system of slide plates P P1 P2 horizontally arranged over
each other, sliding athwart a tube R, R1, R2. The tube R connects the system with
the vacuum drying apparatus the tube R with the hopper A. The plates P, P1, P2 are
connected with the rods S, S1, S2 carrying stop discs n and discs m between these discs
are the open or closed boxes K, K1, K2 with walls W through which the rods S, S¹, S³
pass. The boxes are moved by the rods B by known devices such as are shown in
the drawing the number and sequence of the strokes being equal.
The stroke of K is double as large as the distance between the plates n and m. The
rods S, S1, S2, and with these the slide plates P, P1, P2, are moved only when K, with
the wall W meets the plate n or m, and drives the same forwards or backwards.
During the other half of the stroke K, K1, K2 the rods S, S1, S2 and the slides
P P, P, remain at rest. The latter are so placed that during the movements
of K, K1, K2 at least one of the slide plates is always closed so as to prevent the
entering of air into the apparatus whereas at least one slide plate is opened to permit
free entering of the material from A, R R¹ into the apparatus.
Fig. 7 represents the box K moving in the direction of the arrow so that the
wall W has not yet reached the plate mand in consequence the plate P is at rest.
K' is just about to close completely the slide P¹ and the rod B moving the plate n
on S¹ in the direction of the arrow by means of the wall W.
The rod B of the box K2 has drawn back the rod S2. During the next quarter
revolution of the shaft C, K will begin to open by plate m, the slide P while P¹ is
closed and K2 is moved for of its stroke loosely on S2 in the direction of the arrow
whereby P2 remains open.
In consequence of this movement of the slides P, P1, P2 it is possible as described to
effect hermetically and continuously the feed of the material into the vacuum apparatus
and of course in the same manner the emptying therefrom.
Figs. 10 to 12 represent another form of slide movement. The rods of the slide
plates P P¹ have claws T T guided in a cam slot L arranged on the periphery of a
wheel K. If the wheel is rotated by means of the gear S the rods and slide plates P
and P¹ are alternately moved back and forth. The curving of the slot is so measured
that each slide plate is closed while the other is opened. This is represented by the
diagram of the slot L illustrated in Fig. 12 where D G F EC indicates the slot L.
From this it will be seen that at each revolution of the wheel K, of the revolution
opens the corresponding slide, of the revolution holds the same open, revolution
closes it and revolution retains it closed; further than that during that half revolution
during which one slide (P) is opened and closed, the other slide is retained closed.
A B (Fig. 12) shows the stroke of the claws and consequently of the slide plates.

page_text: The feed and exhaust of the material is analogous to the last mentioned arrange-
ment. Another form of continuous feed or exhaust is represented in Figs. 13 to 16.
It consists in the arrangement of one or more rotary plates having openings destined
for the falling through of the material,
Fig. 13 is a vertical section through such an apparatus with two rotating plates P
and P¹ fixed on the shaft W and rotating with the same. A is the hopper the base R
is secured hermetically to the vacuum drying apparatus. Each plate P and P¹ bas a
hole C, C respectively situated diametrically opposite to each other and sliding
on the stationary plates D and D¹ having holes corresponding thereto but arranged
one above the other. In the illustrated position of the plates P and P¹ the substance
falls from the hopper A through the holes C and E into the closed cavity K while P¹
closes the receptacle R.
In turning the plates for 180° the opening C of the plate P¹ will be before the
opening E¹ of the fixed plate D¹ and plate P will hermetically close the opening E,
the substance in K falls through the opening C¹ and E¹ in the apparatus. The
shaft W consists of two corresponding coupled parts so that if necessary the plates P
and P¹ can be rendered independent from each other.
There being a vacuum in R the pressure of the air holds down the plates P P¹ on
the stationary plates D and D' and tends to form a more perfect closing.
Figs. 15 and 16 represent a substantially similar apparatus with only one rotary
plate. The chamber R is open to the air, R¹ is connected with the vacuum apparatus.
P and P2 are two fixed plates above and below the rotating plate P¹ and having
each a hole A and A2 like a segment. The rotary plate P₁ has a similar hole A' and is
screwed on the shaft W and moves therewith. Fig. 15 shows the moment where the
contents of the opening A' of the plate P₁ fall into the space R and into the
apparatus,
On further turning of the shaft W the opening A¹ moves away from over the
opening A² and arrives under the opening A. After running for 180°, A³ is closed
by the plate P¹ while the opening A¹ is filled at A from the space R, with material
which is thrown out again into R¹ after another turning of 180°.
Fig. 17 represent the vacuum drying apparatus C connected with a continuous
feed A_and_exhaust B. An elevator_E_carries. material.into_the_hopper_whence_it
passes into A and thence through C to B and is thrown out dry from the latter. The
devices before described for continuous feed are especially convenient to such materials
as have a more or less hard and large granulous nature.
Substances of weak, pulpy or fine granulous nature would pass between the surfaces
of the slides or rotary plates thus causing wear thereto.
The latter substances may be fed successively by means of the devices hereinafter
described.
Referring to Figs. 18 to 20. Figs. 18 and 19 represent in longitudinal and cross
section the vacuum drying apparatus as shown in Fig. 1 with the exception of the
hopper. In place of this latter is arranged on the upper cylinder B a flange union
connected by a tube E with a cylinder P in which a plunger K runs back and forth.
P has a hopper D, beneath D the cylinder P is filled with material and the plunger K
pushes the same forward in the tube E in the direction of the arrow, which will be
filled up to the union, the material forming in the tube itself a hermetical plug.
The substance moving at each stroke the stroke regulates the quantity to be filled
in. It can be worked so that the substance filled in continually running through
the cylinders B and C falls dried in F through the opened slide G. The latter can be
closed while the plunger fills the pipe E. This being done K is set at rest and the
material in C falls into F through G when the desired degree of warmth or of drying
is attained.
Fig. 20 shows a modification the filling being done in the same manner as above
described but instead of the long tube E (Fig. 18) a short conically tapered tube E
is used so that the substance is pressed in the narrowed neck of E by the plunger
and forms a completely hermetical closing while being forwarded into the vacuum
drying apparatus.

page_text: With certain substances such as beer returns, coal dust etc., it is preferable to obtain
the dry produce in as concentrated or conglomerated a form as possible. For this
purpose the vacuum drying apparatus as shown in Fig. 19 is may be connected below
tube R with the press P¹. The This device may be applied in the same manner to
many modifications of feed devices.
The dried substance falling into P is pressed by the plunger in the form F and
leaves as a moulded cakė i.
The plunger and form can however have any desired shape, the material also forms
in the shape Fa hermetical closure against the air so that the substance may be
regularly and continuously removed by the device without interrupting the vacuum.
I do not however look upon this device us part of my invention.
Fig. 21 shows a conically tapered hopper T having a screw F fitting thereto and
revolving to compress the substance to be dried into the apparatus and forming a
hermetical closing.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. The combination with a drying cylinder and mechanism C of a cylinder Ba
horizontal hollow barrel S having inclined hollow ridges t t. in. said cylinder B and
an air exhaust in combination therewith substantially as set forth.
2. The combination with a drying cylinder apparatus of a hopper A and rollers i
adapted to be heated for the purpose set forth.
3. The combination of two or more drying apparatus in such manner that the
vapours and heated air arising from the material in the first apparatus are utilized for
heating the heating bodies in the following apparatus there being in the first apparatus
feeble vacuum and high temperature and in the second apparatus greater vacuum and
low temperature.
4. The process and apparatus whereby malt or other substance may be dried in a
vacuum cylinder the latter closed against filling or emptying and the contents baked
at a higher temperature.
5. The apparatus comprising in combination three slide plates P P P arranged one
above the other to divide a hopper into sections, rods S S¹ S plates nm thereon slide
boxes K K K operated in the sequence described for the purpose set forth.
6. The apparatus comprising in combination two slide plates arranged one above
the other to divide a hopper into sections and a wheel having a peripheral slot as set
forth for operating said slide plates for the purpose described.
7. The combination of a receptacle, plates D D' one above the other and dividing
said receptacle into sections, holes E E' respectively in said plates rotary plates P P
having holes C C¹ and arranged for operation in the manner described.
8. The combination of a receptacle parallel superposed fixed plates P P therein
holes A A² therein as set forth and a rotary plate P¹ having a hole A¹ therein and
arranged for operation in the manner described.
9. The combination with a vacuum drying apparatus of a tube E a hopper D and
a plunger K substantially as and for the purpose set forth.
10. The combination-with-a-vaeuum- -drying apparatus of -an--exhaust-or-ontlet
hopper R-a-press-P-having-a-plunger-K-and-shaper-F for the purpose-set-forth.
10. The combination with a vacuum drying apparatus of a substantially conical
hopper T and a screw S shaped thereto substantially as and for the purpose set forth
Dated this und daw of A
1000
Noted the 99nd do at
HERBERT & Co.,
18, Buckingham Street, Strand, London, W.C.,
Agents to Applicant.