A Method of and Apparatus for Drying Moist Materials.
Year: 1896

page_text: Date of Application, 6th May, 1896
Complete Specification Left, 8th Feb., 1897-Accepted, 1st May, 1897
PROVISIONAL SPECIFICATION.
A Method of and Apparatus for Drying Moist Materials.
I EMANUEL STAUBER, Engineer of 11 Anhaltstrasse, Berlin, in the Empire of
Germany do hereby declare the nature of this invention to be as follows:-
My invention has for its object to dry, as quickly as possible, materials containing
much water, for instance peat material, without burning part of such material in
the last stage of the drying process.
By drying apparatus in which the material comes in direct contact with the
products of combustion passing through it the drying process is indeed accelerated,
but the danger of burning is not precluded. By drying apparatus in which the
material is dried by mears of steam pipes there is no danger of burning, but the
drying process takes place very slowly.
The process carried out according to the present invention is as follows: The
moist raw material is first freed from all unbound water by pressing or squeezing.
Then the material is dried in a drying apparatus through which the products of
combustion pass directly and withdraw from the material the greater part of the
bound water it contains. Next the material is conveyed to a cooling apparatus and
from this to a pulverizing or crushing apparatus. By the cooling I remove the
circulating waste steam which would otherwise be mixed again with the material
in the subsequent pulverization. The pulverization is necessary, because, in the
drying, the large pieces break up into small pieces the surfaces of which are covered
with a hard crust enclosing the liquid which may still be present. For obtaining
an effective re-drying or final drying this liquid must of course be exposed again,
which is effected by previous pulverization. From the pulverizing apparatus the
material passes into the re-drying or final drying apparatus wherein it is exposed
to the action of a steam heater. This second drying process takes place compara-
tively quickly, because the greater part of the liquid has been previously removed
and the pulverized material dries rapidly of itself. The burning of parts in the
last stage of the drying process is altogether precluded with this latter mode of
drying.
In carrying the before-described process into effect I use a drying apparatus in
which I arrange above a heating furnace a steam boiler connected with a feed
funnel terminating in one end of a rotary drying drum with oblique conveyor ribs
or the like and having peripheral apertures provided at the other end surrounded
by a fixed casing with suitable openings for the discharge of the dried material,
and the steam from the dried material, and the waste gases from the said heating
furnace.
The material is discharged into a trough shaped receptacle from which an
elevator conveys it to the feed hopper of a drying furnace having several hollow
heating floors. In the said bopper is arranged any desired kind of pulverizing
apparatus which may, for example, consist of two rotary beating, rubbing or
tearing rollers.
In the aforesaid drying furnace I arrange a number of endless
aprons with vertical conveyor plates and intermediate heating plates. The endless
aprons are continually kept in slow motion by suitable rollers or drums. At its
bottom the furnace is provided with an outlet for the dry material and at the top a
discharge pipe for the waste gases and steam, while a second discharge pipe is
under the action of an exhauster and is in connection with the steam heater of the
furnace.
A steam pipe extends through the beforementioned drying drum into

page_text: the lowest hollow heating plate or floor of the beforementioned drying furnace.
The said plates or floors preferably constitute broad flat heating pipes which may
be wholly or partly made of corrugated plates for the purpose of increasing their
heating surface. All the heating pipes are connected with each other alternately
on the right and left hand side by lateral pipes. In the upper heating pipe
terminates the beforementioned discharge pipe.
Dated this 6th day of May 1896.
WHEATLEY & MACKENZIE,
40 Chancery Lane, London, W.C., Agents.
atus for Drying Moist Materiais.
1, EMANUEL STAUBER, Engineer, of 11 Anhaltstrasse, Berlin, in the Empire of
Germany 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 :-
My invention has for its object to dry as quickly as possible, materials
containing much water, for instance peat material, without burning part of such
material in the last stage of the drying process.
By drying apparatus in which the material comes in direct contact with the
products of combustion passing through it the drying process is indeed accelerated
but the danger of burning is not precluded. By drying apparatus in which the
material is dried by means of steam pipes there is no danger of burning, but the
drying process takes place very slowly.
The process carried out according to the present invention is as follows: The
moist raw material is first freed from all unbound water by pressing or squeezing.
Then the material is dried in a drying apparatus through which the products of
combustion pass directly and withdraw from the material the greater part of the
bound water it contains. Next the material is conveyed to a cooling apparatus and
from this to a pulverizing or crushing apparatus. By the cooling I remove the
circulating waste steam which would otherwise be mixed again with the material
in the subsequent pulverization. The pulverization is necessary, because, in the
drying, the large pieces break up into small pieces the surfaces of which are
covered with a hard crust enclosing the liquid which may still be present.
obtaining an effective re-drying or final drying this liquid must of course be
exposed again, which is effected by previous pulverization. From the pulverizing
apparatus the material passes into the re-drying or final drying apparatus wherein
it is exposed to the action of a steam heater. This second drying process takes
place comparatively quickly, because the greater part of the liquid has been
previously removed and the pulverized material dries rapidly of itself. The
burning of parts in the last stage of the drying process is altogether precluded
with this latter mode of drying.
For
The accompanying drawing shows a vertical section of drying apparatus
constructed according to this invention. Arranged above the furnace a are the
steam boiler b, the steam pipe c connected therewith by c and the inlet hopper d.
The hopper d opens into the rotating drying drum e having oblique conveyor ribs f
or the like, and openings g at the other end which are surrounded by a fixed casing
with openings i and k. Au outlet pipe surrounds the opening i and underneath
the opening ka trough like container is fixed from which an elevator m leads into
the inlet hopper n of a tray drying oven. In the hopper n auy desired subdividing
apparatus n is arranged which may for example consist of two striking, grinding, or
tearing rollers rotating against each other. In the drying oven several transport

page_text: belts are arranged with upright carrying laths p and heating plates laying
between them. The transport belts are kept slowly travelling by rotating rollers r.
The drying oven is provided underneath with the outlets and at the top the
chimney t. A second chimney u is acted upon by an exhauster and is in connection
with the steam heating system of the oven. The steam pipe c passes through the
drum e and the connecting pipe v into the lower heating plate g of the drying oven.
The plates g form preferably broad flat heating pipes which for the purpose of
increasing their heating surface are made wholly or partially of rolled plate. All
the heating pipes y are connected together alternately right and left by side pipes w.
The outlet u opens out from the upper heating pipe q. The steam pipe c is provided
with a regulating cock x.
The hot gases from the fire a are drawn through the drum e and the outlet into
the open air. The steam at the same time generated by the fire is superheated in
the steam pipe e and drawn by the exhauster through the outlet u by means of the
pipes cvqwq....... through the drying oven. The material to be dried falls
through the hopper d into the drum e and is carried to the opposite end by the
conveyors f. During this operation it comes into direct contact with the hot gases
and is consequently very quickly dried. The moisture passes away with the hot
gases through the chimney into the open. At the back end the material to be
dried falls through the openings g and k into the container 7 and is here taken by
the elevator m and raised up to the hopper n of the tray-oven, whereby a cooling
and consequent removal of any accompanying vapour takes place. The material is
subdivided in the hopper n by means of the apparatus n', after which the material,
for drying falls on the topmost heating pipe g of the tray drying oven, the carrying
bands op of which, carry it in a zig zag course over the heating pipes g of each tray
down to the outlet s. In this way it is thoroughly dried by the steam heating of
the piping gw. The cock a of the steam pipe c effects the regulation of the flow
of steam. By this apparatus even the wettest material is comparatively quickly
dried in once passing through without danger of burning, the working being
continuous. For the first and final drying processes separate furnaces may be
arranged.
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. Process for the drying of wet materials characterised by the materials under
treatment after being freed from their uncombined water contents by pressure, being
first taken to a drying apparatus in which the material is acted upon directly by the
furnace gases, then to a cooling and subdividing apparatus and finally to a steam
pipe drying apparatus for the purpose of effecting a quick evaporation of the
moisture, without danger of burning, by one passage through the complete
plant.
2. A drying apparatus for carrying out the process described in Claim 1. in
which the hot gases from a steam-boiler furnace a pass through a rotating drying
drum e, the steam created by the fire passing in a superheated condition by means
of a series of pipes cv q w0 g ... through a tray drying oven, whilst the
material for drying passes successively through the preliminary drying drum e,
a cooling transporting arrangement m, a subdividing apparatus n' and the final
drying tray-oven.
3. The method of and apparatus for drying wet materials substantially as
described with reference to the drawings.
Dated this 8th day of February 1897.
WHEATLEY & MACKENZIE,
40 Chancery Lane, London, W.C., Agents.