IMPROVEMENTS IN THE CONSTRUCTION OF FURNACES FOR HEATING, PROALTING, SMELTING, AND PUDDLING METALS, AND IN THE PROCESSES EMPLOYED THEREFOR
Year: 1873

page_text: LETTERS PATENT to Andrew Howatson, of Cronberry Auchinleck,
in the County of Ayr, North Britain, Engineer, for the Invention
of "IMPROVEMENTS IN THE CONSTRUCTION OF FURNACES FOR HEATING,
PROVISIONAL SPECIFICATION left by the said Andrew Howatson at
the Office of the Commissioners of Patents, with his Petition, on
the 13th May 1873.
I, ANDREW HOWATSON, of Cronberry Auchinleck, in the County of
Ayr, North Britain, Engineer, do hereby declare the nature of my In-
vention for "IMPROVEMENTS IN THE CONSTRUCTION OF FURNACES FOR HEATING,
SMELTING, AND PUDDLING METALS, AND IN THE PROCESSES EMPLOYED THEREFOR," to
be as follows:-
:-
The Invention relates to a novel construction of combination furnace
supplied with hot air in lieu of cold, in which the process of heating,

page_text: smelting, and puddling metals may be carried on simultaneously in an
expeditions and economical manner.
The present Invention is designed as a further improvement upon
Letters Patent granted to me on 21st day of December 1870, No.
3337, and relates more particularly to that portion of such Invention
in which heated air or gases are mentioned as being employed as the
agent for maintaining combustion in the furnace during the smelting
and puddling processes.
In order to carry out the object of this my present Invention I
propose heating the air before entering the furnace by an arrangement
of passages or thoroughfares in connection with and so disposed about
the furnace proper, that when the fire of the furnace is ingnited the air
from the outer atmosphere will be drawn through such passages in a
direction towards the bars of the furnace, underneath which it is
delivered, and between which it passes and mingles with the gases
evolved from the fuel of the furnaces, the heated state of such air as it
enters effects a thorough combustion of the gases on passing the bridge,
which consequently produces that intense heat which is necessary for
the purposes of heating, smelting, and puddling metals, in the manner
described and set forth in the Specification of my aforesaid Letters
Patent.
In order that the nature on my Invention may be clearly understood
I will describe as an example one arrangement of the adaptation of my
improvements which I have found to be most efficacious for the purposes
intended, viz., heating the air preparatory to its entering the furnace.
For this purpose I construct the furnace in every respect similar to that
described in my previously recited Letters Patent, with this exception,
that I cause to be constructed under the base of such furnace an
arrangement of air passages or thoroughfares having an entrance thereto
from the outer atmosphere at a point near the floor or base of the
puddling portion of the furnace, underneath which the cool air when
first receiving heat will pass and so keep the floor of such portion of the
furnace cool, and which will in its onward course receive heat which
becomes more and more intense up to the point of its exit underneath
the bars thereof. All the other entrances for feeding the furnace with
air being closed with the exception of this one, thereby allowing none

page_text: but air in a highly heated state to be admitted for supplying the furnaces
with the gases of combustion, which in consequence of their rarified or
heated properties effects a most thorough combustion of the gases evolved
from the fuel of the furnace.
Although I have described one arrangement of the adaptation of my
Invention it will be evident that the arrangement of the same may be
modified or altered in various ways so long as its essential features are
retained, the peculiarity of which consists in drawing air at a point
remote from the furnace into and through passages or thoroughfares so
disposed about the heating, smelting, and puddling furnace, that the air
so entering receiving heat in its onward course will become more and
more intensified until it is finally drawn into the fire from the exit
perforations or apertures underneath the grate bars.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Andrew Howatson in the Great Seal Patent Office
on the 13th November 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ANDREW
HOWATSON, of Cronberry Auchinleck, in the County of Ayr, North
Britain, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirteenth day of May, in the year of
our Lord One thousand eight hundred and seventy-three, in the thirty-
sixth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Andrew Howatson, Her special licence, that
I, the said Andrew Howatson, my executors, administrators, and assigns,
or such others as I, the said Andrew Howatson, my executors, adminis-
trators, and assigns, should at any time agree with, and no others from
time to time and at all times thereafter during the term therein ex-
pressed, should and lawfully might make, use, excrcise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN THE
CONSTRUCTION OF FURNACES FOR HEATING, SMELTING, AND PUDDLING METALS, AND
THE PROCESSES EMPLOYED THEREFOR," upon the condition (amongst others)
1

page_text: that 1, tho said Andrew Howatson, my executors or auSavors, Dy
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 Andrew Howatson, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement:-
The Invention relates to a novel construction of combination furnace
supplied with hot air in lieu of cold, in which the process of heating,
smelting, and puddling metals, may be carried on simultaneously in an
expeditions and economical manner.
The present Invention is designed as a further improvement upon
Letters Patent granted to me on the 21st day of December 1870,
No. 3337, and relates more particularly to that portion of such Invention
in which heated air or gases are mentioned as being employed as the
agent for maintaining combustion in the furnace during the smelting
and puddling processes.
In order to carry out the object of this my present Invention I
propose heating the air before entering the furnace by an arrangement
of passages or thoroughfares) in connection with and so disposed about
the furnace proper that when the fire of the furnace is ignited the air
from the outer atmosphere will be drawn through such passages in a
direction towards the bars of the furnace, underneath which it is
delivered and between which it passes and mingles with the gases
evolved from the fuel of the furnaces, the heated state of such air as it
enters effects a thorough combustion of the gases on passing the bridge,
which consequently produces that intense heat which is necessary for
the purposes of heating, smelting, and puddling metals, in the manner
described and set forth in the Specification of my aforesaid Letters
Patent.
In order that the nature of the Invention may be clearly understood
I will describe as an example one arrangement of the adaptation of my

page_text: improvements which I have found to be most efficacious for the purposes
intended, namely, heating the air preparatory to its entering the furnace.
For this
purpose I construct the furnace in every respect similar to that
described in my previously recited Letters Patent, with this exception,
that I cause to be constructed under the base of such furnace an
arrangement of air passages or thoroughfares having an entrance thereto
from the outer atmosphere at a point near the floor or base of the
puddling portion of the furnace, underneath which the cool air when
first receiving heat will pass and so keep the floor of such portion of the
furnace cool, and which will in its onward course receive heat which
becomes more and more intense up to the point of its exit underneath
the bars thereof. All the other entrances for feeding the furnace with
air being closed with the exception of this one, thereby allowing none.
but air in a highly heated state to be admitted for supplying the furnaces
with the gases of combustion, which in consequence of their rarified or
heated properties effects a most thorough combustion of the gases evolved
from the fuel of the furnace.
Although I have described one arrangement of the adaptation of my
Invention it will be evident that the arrangement of the same may be
modified or altered in various ways so long as its essential features are
retained, the peculiarity of which consists in drawing air at a point
remote from the furnace into and through passages or thoroughfares so
disposed about the heating, smelting, and puddling furnace that the
air so entering receiving heat in its onward course will become more and
more intensified until it is finally drawn into the fire from the exit
perforations or apertures underneath the grate bars.
In order that the Invention may be better understood and explained
in detail, I have hereunto attached a Sheet of Drawings made upon a
scale of about three-fourths of an inch to the foot, similar letters of
reference being marked on corresponding parts of all the Figures alike.
DESCRIPTION OF DRAWINGS.
Fig. 1 represents a longitudinal section of one arrangement of air
passages as applied to my improved furnace for heating, smelting and

page_text: which the heating, smelting, and puddling are carried on; Fig. 3 an
end elevation, and Fig. 4 a section of Fig. 1 through the lines x, x.
In these Figures a, a, aro the outer walls of the furnace; b, the fire-
place; c, the ash-pit; d, the puddling chamber, and e the smelting
chamber, all being parts described and referred to in the Specification of t
Letters Patent herein-before recited. Around and underneath the base
of the combination furnace therein referred to I construct a peculiar
arrangement of air passage or thoroughfare f which has an opening in
the outer wall a of the furnace at a point g remote from the fire-place b
where the air first enters. From this point the air is drawn by the draught
of the fire in a tortuous course along the passages f to the exit orifice i
in the ash-pit c, the openings of which may be so arranged that the hot
air on escaping from such orifice will be diffused so as to be drawn
uniformly through the bars into the fire. The course the air takes from
its entrance into the passage to its exit therefrom is indicated by the 1
arrows shewn in Fig. 2, and by which it will be seen that the cold air is
first subjected to the hottest radiation of heat from the base of the
puddling furnace d from whence it passes into the thoroughfares
constructed in the side walls, and so on to the exit openings i where it is
delivered in a highly heated state into the closed ash-pit c, and from
thence into the furnace. Thus it will be seen that the air in its passage
from the outer atmosphere to the ash-pit on first receiving heat when
passing under the base of the puddling furnace, has a tendency to make
and maintain the floor of the same more durable and perfect than
hitherto, and at the same time in its onward passage it becomes heated :
to a very high degree, in which state it is drawn into the furnace where
it materially assists in the rapid combustion of the gases evolved from
the fuel of the same. The waste heat from the furnace is passed
through the tubes of a steam generator by which means the heat
otherwise lost is utilized for the purpose of generating steam.
Having now described the nature of my said Invention together with
the method of carrying the same into practical effect, I wish it to be
distinctly understood in conclusion that I claim the novel construction
and adaptation to furnaces employed for heating, smelting, and puddling
metal, of an arrangement of passages or thoroughfares into and through
which air supplying the furnaces is drawn in the manner and for the

page_text: purpose, as substantially described, set forth, and fully illustrated in the
Drawings annexed.
In witness whereof, I, the said Andrew Howatson, have hercunto
set my hand and scal, this Third day of November, in the year
of our Lord One thousand eight hundred and seventy-three.
Witness,
HUBT. MAJOR.
ANDREW HOWATSON. (L.S.)