IMPROVEMENTS IN DRYING SOLID SUBSTANCES, AND IN THE APPARATUS OR MEANS EMPLOYED THEREIN
Year: 1866

page_text: LETTERS PATENT to Robert Kunstmann, of Nuremberg, in the Kingdom
of Bavaria, Engineer, but at present residing at 384, City Road, in the
County of Middlesex, for the Invention of "IMPROVEMENTS IN DRYING
SOLID SUBSTANCES, AND IN THE APPARATUS OR MEANS EMPLOYED THEREIN."
Sealed the 22nd March 1867, and dated the 24th September 1866.
PROVISIONAL SPECIFICATION left by the said Robert Kunstmann at the
Office of the Commissioners of Patents, with his Petition, on the
24th September 1860.
I, ROBERT KUNSTMANN, of Nuremberg, in the Kingdom of Bavaria,
Engineer, but at present residing at 384, City Road, in the County of
Middlesex, do hereby declare the nature of the said Invention for "IMPROVE.
MENTS IN DRYING SOLID SUBSTANCES, AND IN THE APPARATUS OR MEANS EMPLOYED
THEREIN," to be as follows:-
This Invention relates to the drying of clay, peat, artificial fuel, sugar,
whitelead, cements, fibrous substances of all kinds, textile fabrics, and other
solid substances and articles, whether in a manufactured state or whilst under
going the process of manufacture.
According to this Invention it is proposed to effect the process of drying
either in a closed chamber in which a partial vacuum is maintained or in a
[Price 8d.1

page_text: closed chamber wherein a pressure is maintained slightly in excess of the
atmosphere, and to employ as the drying medium either a current or currents
of air, the temperature of which is gradually elevated as the drying proceeds,
or superheated or dry steam.
In carrying out this Invention in practice I construct a drying chamber
provided with doors for the introduction and withdrawal of the substances or
articles to be dried; this chamber, if the process of drying be intended to be
carried on in a partial vacuum or under a lower pressure than than of the
atmosphere, must be connected either at the top, bottom, or sides with a fan
or other suitable exhauster capable of maintaining a slight diminution of
pressure in the interior of such chamber. Opposite to that portion of the
chamber where the communication with the exhauster is effected I cause a
current of air to enter such chamber in a finely divided or dispersed con-
dition, and for this purpose I find it convenient to cause such air to pass
through a finely perforated plate or wire gauze extending over the entire area
of that portion of the chamber wherein it is admitted. In some cases I also
employ a second perforated plate or wire guage extending over the entire area
of that portion of the chamber whence the air is drawn off by the exhauster,
but the area of the perforations for the incoming air should be less than that
of the perforations or outlet for the outgoing air, so that a slight vacuum or
diminution of pressure may be maintained inside the drying chamber; this is
of great importance in drying bicks and similar articles which are liable to
crack in the process of drying. In treating articles of this description it is
also important, in order to prevent cracking, that the temperature of the air
be gradually elevated as the drying proceeds, for which purpose I introduce
hot and cold air in regulated proportions by the aid of cocks or valves in the
pipes for that purpose according to the temperature required, and intimately
mix the same together in a mixing chamber by means of a revolving agitator
before allowing such air to enter the drying chamber. In many cases the
hot air may be obtained from pipes or flues heated by the waste heat of the
furnaces or fires employed on the works; for example, in brick and cement
works the waste heat from the kilns may be used for that purpose. I do not
confine myself to any particular mode of drying or heating the air.
According to another system of drying I propose to admit superheated or
dry steam into the drying chamber, and to maintain a slight excess of
pressure therein above that of the atmosphere, for which purpose the per-
forations through which the steam enters the chamber should be of larger area
than the area of the perforations or outlet for the exit of such steam from the
said chamber; or in lieu of superheated or dry steam, dry air of the required

page_text: temperature may be employed and maintained at a slight pressure in the
drying chamber in the manner above described with reference to the use of
superheated or dry steam.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Robert Kunstmann in the Great Seal Patent Office on the
23rd March 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
KUNSTMANN, of Nuremberg, in the Kingdom of Bavaria, Engineer, but at
present residing at 384, City Road, in the County of Middlesex, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fourth day of September, in the year of our
Lord One thousand eight hundred and sixty-six, in the thirtieth year of Her
reign, did,for Herself, Her heirs and successors, giveandgrautunto me, the said
Robert Kunstmann, Her special licence that I, the said Robert Kunstmann,
my executors, administrators, and assigns, or suchothers as I, the said Robert
Kunstmann,myexecutors, administrators, and assigns,shouldat any time agree
with, and no others, from time to time and at all times thereafter during the
term therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN DRYING SOLID
SUBSTANCES, AND IN THE APPARATUS OR MEANS EMPLOYED THEREIN," upon the
condition (amongst others) that I, the said Robert Kunstmann, ny exe-
cutors or administrators, by an instrument in writing under my, or their,
or one of their hands and seals, should particularly describe and ascertain
the nature of the said Invention, and in what manner the same was to be
performed, and cause the same to be filed in the Great Seal Patent Office
within six calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that I, the said Robert Kunstmann, do hereby declare
the nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement,reference being had to theaccompanying Sheet of Drawingsforming
part of this Specification:-
This Invention relates to the drying of clay, peat, artificial fuel, sugar,
whitelead, cements, fibrous substances of all kinds, textile fabrics, and other

page_text: solid substances and articles whether in a manufactured state or whilst
undergoing the process of manufacture.
According to this Invention it is proposed to effect the process of drying
either in a closed chamber in which a partial vacuum is maintained, or in a
closed chamber wherein a pressure is maintained slightly in excess of the
atmosphere, and to employ as the drying medium either a current or currents
of air, the temperature of which is generally elevated as the drying proceeds,
or superheated or dry steam.
In carrying out this Invention in practice I construct a drying chamber
provided with doors for the introduction and withdrawal of the substances or
articles to be dried. This chamber, if the process of of drying be intended to
be carried on in a partial vacuum or under a lower pressure than that of the
atmosphere, must be connected either at the top, bottom, or sides with a fan or
other suitable exhauster, capable of maintaining a slight diminution of pressure
in the interior of such chamber. Opposite to that portion of the chamber
where the communication with the exhauster is effected I cause a current of
air to enter such chamber in a finely divided or dispersed condition, and for
this purpose I find it convenient to cause such air to pass through a finely
perforated plate or wire gauze extending over the entire area of that portion
of the chamber wherein it is admitted. In some cases I also employ a second
perforated plate or sheet of wire gauze extending over the entire area of that
portion of the chamber whence the air is drawn off by the exhauster, but the
area of the perforations for the incoming air should be less than that of the
perforations or outlet for the outgoing air, so that aslightvacuum ordiminution
of pressure may be maintained inside the drying chamber; this is of great
importance in drying bricks and similar articles which are liable to crack in
the process of drying. Intreating articlesofthisdescription it is alsoimportant,
in order to prevent cracking, that the temperature of the air be gradually
elevated as the drying proceeds, for which purpose I introduce hot and cold
air in regulated proportions by the aid of cocks or valves in the pipes for that
purpose according to the temperature required, and intimately inix the same
together in a mixing chamber by means of a revolving agitator before allowing
such air to enter the drying chamber. In many cases the hot air may be
obtained from pipes or flues heated by the waste heat of the furnaces or fires
employed on the works, for example, in brick and cement works the waste
heat from the kilns may be used for that purpose. I do not confine
myself to any particular mode of drying or heating the air. According
to another system of drying, I propose to admit superheated or dry steam
into the drying chamber, and to maintain a slight excess of pressure

page_text: therein above that of the atmosphere, for which purpose the perforations
through which the steam enters the chamber should be of larger area than
the area of the perforations or cutlet for the exit of such steam from the said
chamber; or in lieu of superheated or dry steam, dry air of the required
temperature may be employed and maintained at a slight pressure in the
drying chamber in the manner above described with reference to the use of
superheated or dry steam.
especially for drying of the bricks or other article in a partial vacuum;
Figure 2 is a vertical section ou the line x, x, Figure 1, Figure 3 is a hori-
zontal section on the line y,y,Figure 2; like letters indicate the same parts in
each of the Figures.
The drying chamber A is constructed of sheet iron or other suitable
material, and is made of any desired size and shape. The said chamber is
provided with doors which are arranged in the most convenient position to
allow the bricks or other articles to be readily introduced and removed, and
the said articles are supported upon the shelves A¹, or in anyother convenient
manner which allows the air to circulate freely round them. The fan B for
exhausting the air from the said chamber is in this case arranged at the top
of the same, and is driven by the belt C from a steam engine or other motive
power. The fan chamber B' is divided from the drying chamber A bythe per-
forated plate D; another perforated plate or sheet of wire gauze E is placed
at the lower end of the chamber A. The perforations or apertures in the
plate E are finer or smaller than those in the plate D. By means of these two
perforated plates the air is caused to pass equally through all parts of the
chamber A, and the difference in the size of the apertures in the said plates
allows the desired partial vacuum to be maintained in the same. The pipe F
communicates with a furnace or other vessel containing hot air, which is
conducted by the said pipe to each of the tubes G, cold air is at the same
time supplied to the said tubes by the pipe H, and the hot and cold air are
properly mixed in the said tubes before being admitted into the chamber A.
The tubes G are perforated to allow the mixed air to pass therefrom into the
said chamber. The pipes F and H are provided with cocks, dampers, or other
suitable devices to regulate the supply of hot and cold air; by this means
the temperature of the currents of air passing through the chamber A are
regulated to suit the nature of the substance or article being dried.
The arrangement of parts represented in the Drawing is more especially

page_text: adapted for drying articles and substances which will stand a high temperature
without being injured thereby, but for drying others which require a more
gradual treatment the drying chamber is constructed of brick work, and is
preferably made larger in order that a greater number of bricks or other
articles may be introduced at one time. In this case the cold air is conducted
through an arched passage which extends along the top of the drying chamber,
the top of which passage is perforated with holes for the admission of cold
air, and whose bottom is also perforated with holes to admit the same to the
drying chamber. The hot air passes through pipes which extend through the
said passage, and these pipes are perforated to allow the heated air to escape
and mingle with the cold air in the same before it passes into the drying
chamber; the bottom of the latter is perforated and communicates with
another passage below the drying chamber at the end, which passage the fan
or exhausting apparatus is placed.
By the employment of my improved method of admitting, distributing, and
regulating the currents of air the bricks or other articles are dried equally
throughoutwith great rapidityandwithout danger of fracture or other injury.
Having thus fully described my said improvements, and shown how the
same maybe convenientlyand advantageously carried into practice, I claim,
First, drying bricks or other articles or substances by means of currents of
air mixed, regulated, and distributed in a chamber wherein a partial vacuum
is maintained, substantially in the manner set forth.
Second, drying bricks or other articles or substances by currents of air or
steam in a chamber wherein a slight pressure is maintained, substantially in
the manner set forth.
In witness whereof I, the said Robert Kunstmann, have hereunto set
my band and seal, this Twenty-third day of March, in the year of
our Lord One thousand eight hundred and sixty-seven.
ROBERT KUNSTMANN. (L.S.)