IMPROVEMENTS IN DRYING APPARATUS FOR TREATING PULP AND OTHER SUBSTANCES
Year: 1884

page_text: I ARNOLD MUNZINGER of Olten in Switzerland, Manufacturer, do hereby
declare the nature of said invention for "IMPROVEMENTS IN DRYING APPARATUS
FOR TREATING PULP AND OTHER SUBSTANCES "
to be as follows:-
This invention has for object improvements in apparatus for drying wool, cotton,
grain and other materials at a low temperature.
The material to be dried is placed in a box, case or vessel through which a
current of dry air is made to pass-entering at the bottom and passing out at the
top; whilst an agitator keeps the material in motion and effects its gradual delivery
at the back or bottom. The box or vessel is, by preference, of an upright
cylindrical or prismatic form, and is provided at or near the bottom with a small
aperture for the exit of material and with an air inlet near the aforesaid aperture.
This inlet serves for the introduction under pressure of warm or dried air, which
passes in an upward direction through the material to be dried. The box or vessel
is provided, according to the nature of the material to be treated, with appliances
to prevent the formation of interstices or hollow spaces: that is, with an agitating,
stirring, beating, shaking or centrifugal apparatus to secure an even distribution of
the material.
The material may be introduced into the box or vessel by a creeper or conveyer
delivering over a rotary distributor on a vertical shaft which also carries beaters
or stirring arms and a screw for the delivery of the dried material at the bottom.
The size of the outlet can be regulated by an adjustable bell over which the
material falls into a funnel, and thence into a hopper or receiver whence it is
removed by any suitable means, as for instance, by a belt carrying cups.
To prevent the air duct becoming stopped up, a guard plate is fixed over the air
outlets. Some kinds of material can be delivered more satisfactorily by means of
withdrawing rollers, capable of adjustment so that the space between them may be
regulated according to the speed of delivery required.
In some cases one roller working against a plain or curved surface is sufficient.
The speed of delivery of the dried material may be also regulated by the
number of revolutions of the rollers. To ensure the material being evenly
distributed in the box or vessel it may be fed through a tube carried round and
round by a rotating arm over the feed inlet. If it should require to be broken
Dries 0.71

page_text: first it is passed through toothed, grooved or serrated rollers on its way to the inlet.
For the rotary or stirring apparatus there may be substituted various other
analogous devices as, e.g., a shaking apparatus working in conjunction with a sieve
which sieve is shaken by an eccentric. The stirring or shaking motion causes the
rebounding of the material from the circumference and thus effects an even drying.
Certain materials such as wool and cotton must not be subjected to this process as
their fibrous nature would tend to entanglement.
As the material is piled up in the box or vessel and exit downwards is not
allowed to the air which is forced in, the dry air-which on its entrance into the
shaft is warm can at the bottom energetically act upon the slowly descending
material and thus obtain its highest degree of efficiency; the driest and warmest
air encounters first of all that stuff which is furthest advanced in the process of
drying and the higher the air goes and the cooler and more saturated it becomes,
the wetter the stuff it meets with.
Thus the apparatus can work with a comparatively low temperature, which is
chiefly of importance where the material to be treated is wood; for if wood or
cellulose are dried by air which is too hot the resin components of the material
undergo a change.
"
I, ARNOLD MUNZINGER, of Olten, in Switzerland, Manufacturer, do hereby
declare the nature of my invention for "IMPROVEMENTS IN DRYING APPARATUS FOR
TREATING PULP AND OTHER SUBSTANCES and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement :—
This invention has for object improvements in apparatus for drying wool cotton
grain and other materials at a low temperature.
The material to be dried is placed in a box case or vessel through which a current
of dry air is made to pass entering at the bottom and passing out at the top whilst
an agitator keeps the material in motion and effects its gradual delivery at the
back or bottom.
The box or vessel is by preference of an upright cylindrical or prisinatic form
and is provided at or near the bottom with a small aperture for the exit of material
and with an air inlet near the aforesaid aperture. This inlet serves for the
introduction under pressure of warm or dried air which passes in an upward
direction through the material to be dried: The box or vessel is provided according
to the nature of the material to be treated with appliances to prevent the formation
of interstices or hollow spaces: that is with an agitating, stirring, beating, shaking,
or centrifugal apparatus to secure an even distribution of the material.

page_text: The material may be introduced into the box or vessel by a creeper or conveyer
delivering over a rotary distributor on a vertical shaft which also carries beaters or
stirring arms and a screw for the delivery of the dried material at the bottom.
The size of the outlet can be regulated by an adjustable bell over which the
material falls into a funnel and thence into a hopper or receiver whence it is
removed by any suitable means as for instance by a belt carrying cups.
To prevent the air duct becoming stopped up a guard plate is fixed over the air
outlets. Some kinds of material can be delivered more satisfactorily by means of
withdrawing rollers, capable of adjustment so that the space between them may be
regulated according to the speed of delivery required.
In some cases one roller working against a plain or curved surface is sufficient.
The speed of delivery of the dried material may be also regulated by the number
of revolutions of the rollers. To ensure the material being evenly distributed in the
box or vessel it may be fed through a tube carried round and round by a rotating
arm over the feed inlet.
If it should require to be broken first it is passed through toothed grooved or
serrated rollers on its way to the inlet.
For the rotary or stirring apparatus there may be substituted various other
analogous devices as e.g. a shaking apparatus working in conjunction with a sieve
which sieve is shaken by an eccentric. The stirring or shaking motion causes the
rebounding of the material from the circumference and thus effects an even drying.
Certain materials such as wool and cotton must not be subjected to this process as
their fibrous nature would tend to entanglement.
As the material is piled up in tlie box or vessel and exit downwards is not allowed
to the air which is forced in, the dry air-which on its entrance into the shaft is
warm can at the bottom energetically act upon the slowly descending material
and thus obtain its highest degree of efficiency; the dryest and warmest air
encounters first of all that stuff which is furthest advanced in the process of drying
and the higher the air goes and the cooler and more saturated it becomes, the wetter
the stuff it meets with.
Thus the apparatus can work with a comparatively low temperature which is
chiefly of importance where the material to be treated is wood; for if wood or
cellulose are dried by air which is too hot the resin components of the material
undergo a change.
In the accompanying drawings Fig I is a vertical section of a drying apparatus
provided with simple stirring or agitating appliances; Fig II is a similar view of
a drying apparatus provided with modified arrangements of appliances for stirring
or agitating the material under treatment and effecting its evacuation.
Fig III shews a modified arrangement of distributing and feeding appliances.
Fig IV shews & modified arrangement of rollers for expelling the contents of the
apparatus.
Fig V is a vertical section of a drying apparatus provided with improved agitating
appliances.
Fig VI is a top view of the same, the cover Z being removed.
Fig VII is a vertical section of another modification of the improved drying
apparatus provided with other forms of agitating apparatus.
Fig VIII is a top view of same, the cover Z being removed.
Fig IX. is a horizontal section on line A. B of Fig VII.
Fig X. is a horizontal section on line C. D of Fig VII.
The apparatus consists of a vessel or receptacle A, which with the exception of
a small outlet a for the dried material, is entirely closed at the bottom and
communicates, above the outlet a with an air channel through which warm or dried
air is forced. This air is unable to escape downwardly but ascends through the
substances requiring to be dessicated, and which are placed in the vessel A.
According to the nature of these substances, there are arranged inside the vessel or
receptacle A appliances which have for their object to prevent the formation of
irregular interstices or cavities in the said substances,

page_text: Fig I shews a drying apparatus into which loose and wet substances are fed by
means of the conveying cloth b. They are delivered on to a rotating distributor d
which may be fluted if required, and drop from it into the receptacle A. Upon a
rotating vertical shaft fare mounted (besides the distributor d) the stirring arms e
and at the lowest part of the vessel or receptacle is arranged the screw g serving
for the expulsion of the substances already dried. The bell h serves to regulate the
capacity of the outlet a the dried substances falling from the latter over the said
bell h, into the hopper i and from this into the trough K. From this trough they
are removed by any suitable conveying means (such as an elevator belt provided
with buckets).
The modification of the drying apparatus shewn in Fig II relates mainly to the
rollers m which serve for the evacuation of the substances under treatment, and
together form the outlet a¹. In order to cause the material in the vessel to settle
in a regular manner, stirring discs which may be provided when required, with the
rakers e², are used as a substitute for the stirring arms e shewn in Fig I. Instead
of two or more rollers m, one may be found sufficient; in this case the outlet
would be formed on one side by the roller and on the other by one wall of the
hopper. The hopper may be dispensed with, by the employment of two large
rollers substituted therefor, as shown in Fig IV. Such a modification is chiefly
useful when the material operated upon requires a large surface for its successful
delivery. The quantity of dried material which issues from the vessel, when the
rollers m are employed is regulated by altering the distance between the shafts
(and consequently-enlarging or diminishing the capacity of the outlet a¹) and by
increasing or decreasing the speed of the rollers.
Fig III shews a modification of the feeding distributor in which a pipe d³ is
caused to move round at the top of the vessel or receptacle by means of a rotating
arm p. In the same figure there is also shewn an arrangement applicable to
substances which previously to being dried are subjected to a crushing process;
the two ribbed rollers q crush the material passing between them before it falls into
the hopper and into the pipe d².
The modification shewn in Fig IV is particularly suitable for substances consisting
of long fibres.
The stirring and agitating motion assists in effecting a regular and thorough
dessication.
In Figs V and VI is illustrated an improved stirring arrangement by means of
which substances requiring dessication are caused to descend by a step-by-step-like
motion, by means of fixed and moving arms s and e.
In this form of drying apparatus, arins arranged in the shape of a spiral staircase
are fixed in the walls of the receptacle, (these arms are shewn in the present
construction as being arranged in a helical form of uniform pitch). Instead of
giving to the said arms the form of a helix with uniform pitch, they may also
assume that of a helix with varying pitch or they may make double pitched helical
or screw like convolutions such arrangements being highly advantageous for drying
apparatus of large dimensions.
The shaft f carries directly or indirectly by means of a sleeve F rigidly keyed to
it so that the two form but one piece (as shewn in the figures) an arm or scraper e
for each fixed arm. These scrapers may be provided with brushes on their edges
which face the fixed arms.
In order that the scrapers should not all operate simultaneously they are arranged
in such a manner that two adjacent scrapers form together, as shewn in the
plan, a different angle to that formed by two adjacent fixed arms; thus, (as shewn
in plan Figs VI and IX) there are used five scrapers for six fixed arms, so that a
certain quantity of material accumulates by the side of each scraper, and hence, the
helix formed by the scrapers has a different pitch to that of the helix formed by
the fixed arms.
The steps are perforated in order to allow the dried air to penetrate through the
substances which are being dessicated. Z is an ordinary cover which holds the central

page_text: shaft Ffin position; the scraper eo serves to level the material. c is the air channel,
n is a valve to prevent the obstruction of the said air channel, g is a screw placed
in the hopper fixed to the vessel or receptacle and his the bell movable in an
upward direction and placed under the outlet for the material.
In order to regulate this outlet with regard to the pressure under which the
substances arrive to it, there is employed a lever W fixed to the bell and carrying
a weight movable upon one of its armis.
In order that a certain quantity of material may be permitted to collect in the
hopper, without boing forth with expelled by the screw g the arrangement shewn in
Fig V allows of the screw g being thrown out of action by means of the lever
and sleeve y and the wheel X, which is keyed so as to slide upon the nave of the
screw.
The modification shewn in Fig VII to X comprises likewise a scraper e which
stirs the material by scraping the fixed arms 8 and three plates p¹, p³, p³ above the
fixed arms 8 over which the scrapers also pass.
One or several of these plates may be used, one however being sufficient to
prevent the air from escaping too easily. The said plates are so arranged that they
close upon the helical fixed arms. Each plate has an opening which corresponds
in pitch and length with an opening below it. One set of these openings marked q¹
next the perforated part al is shewn in Fig VIII and from that will be understood
the position of the other openings q³, g³, which correspond to the plates p³, p³, but
are not shewn.
Thus, the plate p³ has an opening q³ which corresponds in size and position with
the nearest fixed arm below and the part 3 of the plate p³ is perforated so as to
correspond in direction and size with one fixed arm and upon this part are also
placed the substances requiring dessication.
The next plate p³ has an opening q³ situated above the perforated part of the
plate p and the subsequent plate p¹ (shewn at the top in the drawing) has likewise
an opening g' situated above the perforated part 8³ of the plate p³.
Fig VIII is a plan of the apparatus, the cover Z being removed, and shows the
top plate p¹ its sieve s' and opening q².
The air enters from the channel Cinto the box c¹ which has a straight or angular
cover u provided with perforations, its position being such that the dried material
falls from the last step 8 upon the said cover u.
Fig X is a plan of the same arrangement corresponding to the horizontal
section C. D, whilst Fig 1X is a section at A. B and consequently a plan of a series
of the fixed arms (as in Fig VI).
When the arms are constructed so as to form a helix with varying pitch, several
boxes like C must be employed.
The above described apparatus with helical arms and scrapers may also be
provided with rollers for the outlet of material such as are used in the modifications
shewn in Figs II to V, the said rollers serving as a substitute for the screw g.
The apparatus may also be constructed in such a manner, that the arms a may
be caused to rotate with the sleeve F. and the scrapers e may be fixed to the
receptacle A.
The apparatus may be further modified by causing the casing A to rotate and
the sleeve F. to become a fixture.
As the stuff in the receptacle A may be of various densities and may be thrown
down from a great height the air being moreover prevented from escaping
downwardly, the dry and warm air entering at the bottom operates energetically
in dessicating the layers of material which sink slowly, and the best effects are
thus obtained from its action.
Having now particularly described and ascertained the nature of my said
nvention and in what manner the same is to be performed, 1 declare that what
I claim is:-
1. The use for treating pulp and other substances of a drying apparatus
comprising a vessel or receptacle which receives at its upper part material to be

page_text: dried and at its lower part a current of dry or heated air, and through which there
is maintained a descending current of material to be dried and an ascending current
of air substantially as described.
2. In drying apparatus for treating pulp and other substances the use in combi-
nation with a vessel or receptacle which receives at its upper part material to be
dried and at its lower a current of dry or heated air, of appliances, such as elevators,
for feeding the material at the upper part, and other appliances, such as worms or
rollers for effecting the evacuation of the material together with air channels
Bituated above the outlet, substantially as described.
3. In drying apparatus for treating pulp and other substances the use in
combination with a vessel or receptaclo which receives at its upper part material
to be dried, and at its lower part a current of dry or heated air, of a distributor
such as d or d for feeding the material regularly, substantially as described.
4. In drying apparatus for treating pulp and other substances the use in
combination with a vessel or receptacle which receives at its upper end material
to be dried and at its lower end a current of dry or heated air, of a screw for
effecting the evacuation of the substances under pressure, and a bell or plate for
regulating the pressure substantially as described.
5 In drying apparatus for treating pulp and other substances the use in
combination with a vessel or receptacle which receives at its upper part material
to be dried and at its lower part a current of dry or heated air, of agitating
apparatus for effecting the regular descent of the material and for ensuring its
thorough exposure to the ascending air substantially-as described.
6. The improved drying apparatus for treating pulp and other substances con-
structed, arranged and operating substantially as described with reference to Fig 1
and to Fig 2 of the drawings.