IMPROVEMENTS IN THE FURNACES USED IN THE MANUFACTURE OF SODA OR ALKALI
Year: 1855

page_text: LETTERS PATENT to James Murdoch Napier, of the York Road, Lambeth,
in the County of Surrey, for the Invention of IMPROVEMENTS IN THE
FURNACES USED IN THE MANUFACTURE OF SODA OR ALKALI."
Sealed the 7th August 1855, and dated the 12th March 1855.
PROVISIONAL SPECIFICATION left by the said James Murdoch Napier
at the Office of the Commissioners of Patents, with his Petition, on the
12th March 1855.
I, JAMES MURDOCH NAPIER, of the York Road, Lambeth, in the County of
Surrey, do hereby declare the nature of the Invention for "IMPROVEMENTS IN
THE FURNACES USED IN THE MANUFACTURE OF SODA OR ALKALI" to be as follows:-
This Invention has for its object improvements in the construction of the
furnaces used in that part of the manufacture of soda or alkali where the wet
salt of soda is dried and roasted or carbonated. And the improvements consist
of constructing a furnace bottom of a series of shelves or surfaces which by
their movement cause the materials under process progressively to be moved
from one shelf or surface to the next shelf or surface, and thus the materials to
be dried and roasted or carbonated may be constantly or at short intervals
received in at one end and delivered out at the other end of a furnace; and to
economise heat as much as may be, the products of combustion having heated
the furnace, and the matters progressively moved through it (by the movement

page_text: of parts of the bottom of the furnace), pass through, between, and amongst
inclined shelves, down which the matters to be acted on are caused to descend
by mechanical action, and thus will the matters receive a preparatory action of
heat before they reach the furnace.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed 5
by the said James Murdoch Napier in the Great Seal Patent Office
on the 12th September 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
MURDOCH NAPIER, of the York Road, Lambeth, in the County of Surrey,
send greeting..
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twelfth day of March, in the year of our Lord
One thousand eight hundred and fifty-five, in the eighteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said James Murdoch Napier, Her special licence that I, the said James
Murdoch Napier, my executors, administrators, and assigns, or such others,
as I, the said James Murdoch Napier, my executors, administrators, and
assigns, should at 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 THE FURNACES USED IN THE MANUFACTURE OF
SODA OR ALKALI," upon the condition (amongst others) that I, the said James
Murdoch Napier, by an instrument in writing under my hand and seal,
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 James Murdoch Napier, do hereby
declare the nature of the said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement thereof (that is to say):-
This Invention has for its object improvements in the construction of the
furnaces used in that part of the manufacture of soda or alkali where the wet
salt of soda is dried and roasted or carbonated. And the improvements consist
of constructing a furnace bottom of a series of shelves or surfaces which by

page_text: their movement cause the materials under process progressively to be moved
from one shelf or surface to the next shelf or surface, and thus the materials to
be dried and roasted or carbonated may be constantly or at short intervals
received in at one end and delivered out at the other end of a furnace; and to
economise heat as much as may be, the products of combustion having heated
the furnace, and the matters progressively moved through it (by the movement
of parts of the bottom of the furnace), pass through, between, and amongst
inclined shelves, down which the matters to be acted on are caused to descend
by mechanical action, and thus will the matters receive a preparatory action of
heat before they reach the furnace.
Having thus stated the nature of my said Invention, I will proceed more
fully to describe the manner of performing the same.
DESCRIPTION OF THE DRAWING.
Figure 1 on the annexed Drawing shews a longitudinal section of furnace
No. 1; Figure 2 is a similar section of furnace No. 2; Figure 3 shews a plan
end view of both the
in section of the furnaces; and Figure 4 represents an
furnaces. When the same part is indicated in more than one Figure it is
denoted by the same letters in each Figure.
A, Figure 1, is a receiver, into which the wet salt of soda is put; B is a
revolving rake, which is regulated in speed so as to feed the material into the
furnace at the rate desired; a, a, a, are fixed shelves formed of fire brick placed
upon iron bed plates, which pass from wall to wall across the furnace; b, b, b,
are shelves of a similar kind, but they are attached to the vibrating frame C,
which is worked to and fro upon its wheels D by the excentrics E, E, through
the connecting rods d, d, and thus by the action given to the alternate shelves
the material is made to progress through the furnace, descending step by step
until it is thrown upon the sieve M, to which a quick vibrating motion is
applied for sifting the salt; F is a worm for collecting the fine portion of the
material which has passed through the sieve, and for conveying it to the elevator
G, which raises it to the distributing worm L, by which it is passed into the
hopper T of furnace No. 2; H is a rolling mill, into which the lumps which
do not pass the sieve fall and are crushed; I is a worm for collecting the
crushed matter and passing it on to the elevator J, which raises it to be returned
to the furnace by the distributing worm K.
The fires for heating the furnaces are at N, N, and the products of com-
bustion after passing over the matter under treatment escape by the flues e;
O, Figure 2, is an iron case containing a number of inclined shelves, down
which the matter under treatment is made to pass by the action of a number

page_text: of pins working through holes in the back plate of the iron case and pushing
the matter forward, which as it lays upon the inclined shelves is submitted to
the action of the heat and products of combustion from the furnace before it
falls on to the first fire brick of the furnace bottom to be progressively passed
from shelf to shelf, as in furnace No. 1, until it descends from the last shelf
through the inclined box P into the truck Q. Provision is made for closing
the bottom of the inclined box P, while the full truck is being replaced by an
empty one. R is the main shaft, through which the power is transmitted to
the various parts requiring motion. The vibrating frame C can be withdrawn
from the furnace by the doors S, S, when repairs are required to the brickwork.
Furnace No. 1 is intended to operate with a moderate heat, but so as thoroughly
to dry the material, which is afterwards passed to No. 2 furnace, then to undergo
a much stronger heat. The arrangement explained above for returning the
matter crushed by the rolls back, to pass again through the furnace No. 1, is
introduced in order to prevent the delay which would arise if the matter
is moved through the furnace slow enough to permit the lumps to be dried
completely.
Having thus described the nature of my said Invention, and the manner of
performing the same, I would have it understood that I do not confine myself
to the details so long as the peculiar character of my Invention be retained;
but what I claim is, the combination of the parts of a furnace herein described
to be used in the manufacture of soda or alkali.
In witness whereof, I, the said James Murdoch Napier, have hereunto
set my hand and seal, this Twelfth day of September, in the year of
our Lord One thousand eight hundred and fifty-five.
Witness,
JNO. ALCOCK.
JAMES M. NAPIER. (L.S.)