IMPROVEMENTS IN FURNACES FOR BURNING LIME, ROASTING ORES, AND FOR OTHER PURPOSES, AND IN APPARATUS CONNECTED THEREWITH, MORE ESPECIALLY WITH A VIEW TO UTILIZING THE EFFLUENT GASES FOR EVAPORATING PURPOSES
Year: 1875

page_text: Sealed the 14th September 1875, and dated the 31st March 1875.
PROVISIONAL SPECIFICATION left by the said James Thomas Lockey
at the Office of the Commissioners of Patents, with his Petition,
on the 31st March 1875.
I, JAMES THOMAS LOCKEY, of Northwich, in the County of Chester,
Mechanical Engineer, do hereby declare the nature of the said Inven-
tion for "IMPROVEMENTS IN FURNACES FOR BURNING LIME, ROASTING ORES, AND
FOR OTHER PURPOSES, AND IN APPARATUS CONNECTED THEREWITH, MORE ESPECIALLY
WITH A VIEW TO UTILIZING THE EFFLUENT GASES FOR EVAPORATING PURPOSES," to
be as follows :—
My Invention chiefly consists,-
Firstly. Of two furnaces similar in most respects to those used in
heating steam boilers which I will henceforth call the furnaces.

page_text: 2nd. In a reverberatory furnace or calcining kiln placed between
these furnaces and seperated only by a party wall. This furnace or kiln
I will henceforth call the kiln.
The two furnaces and kiln are constructed parallel to each other, their
fronts being in the same vertical plane. All three are lined and arched
with fire-bricks or other refractory material, and their front and back
walls are in line. On these walls above the arches and extending back a
long distance on walls and pillars in the usual manner I place a salt
or other evaporating pan or drying floor, as may be required, having
flues below separated from the furnaces and kiln by the back wall. The
hinder part of each furnace communicates with the kiln, and through
these communications the products of combustion pass into the said
kiln. After permeating the pile of limestone or ore, or heating gas
retorts, as the case may be, the gases then escape through a slit in the
top of the kiln near the front wall and proceed into the flue under the
pan or drying floor to the other extremity, and thence up the chimney.
Sometimes when the salt pans are thus heated the effluent products of
combustion are passed under the drying floors to still further utilize the
heat.
In order to increase the draft I usually place one or more fire-brick
tubes or flues over the kiln or the party walls (by preference two circular
flucs in the latter position), into cither of which the gases from the kiln
are drawn (after passing through the slit) by means of a steam jet.
This causes a pressure under the pan slightly greater than that of the
atmosphere, there is thus a constant pressure outward causing a splendid
draft without the use of a chimney, and entirely preventing indrafts of
cold air through defective walls.
To prevent the steam jet causing a strong current through the centre
only of the flue beneath the pan I place cross walls so arranged as to
cause a split draft, and make the products of combustion follow a
circuitous course.
The arches over the furnaces may be dispensed with altogether, or
made if desirable with numerous vent holes so as to allow a portion of
the gases to ascend at once and heat that part of the pan above them;
but this is usually not desirable, the main object of the arches being to
preserve the pans from the fierce direct radiant heat of the furnace so
destructive in the arrangements hitherto employed.

page_text: One of the chief advantages of this form of apparatus besides the
great economy of fuel which it effects is that by firing the two furnaces
alternately cach in turn burns the others smoke as it passes into the
combustion chamber.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said James Thomas Lockey in the Great Seal Patent
Office on the 29th September 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
THOMAS LOCKEY, of Northwich, in the County of Chester, Mechanical
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirty-first day of March, in the year
of our Lord One thousand eight hundred and seventy-five, in the thirty-
eighth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said James Thomas Lockey, Her special
license that I, the said James Thomas Lockey, my executors, admini-
strators, and assigns, or such others as I, the said James Thomas
Lockey, 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 FURNACES FOR BURNING LIME, ROASTING ORES, AND FOR OTHER
PURPOSES, AND IN APPARATUS CONNECTED THEREWITH, MORE ESPECIALLY WITH A
VIEW TO UTILIZING THE EFFLUENT GASES FOR EVAPORATING PURPOSES," upon
the condition (amongst others) that I, the said James Thomas Lockey,
my executors 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 tho
Great Seal Patent Office within six calendar months next and imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said James Thomas Lockey, do hereby
declare the nature of the said Invention, and in what manner the

page_text: same is to be performed, to be particularly described and ascertained
in and by the following statement thereof, reference being had to tho
accompanying Sheet of Drawings, and to the figures and letters marked
thereon, that is to say :-
Firstly. Of two furnaces similar in most respects to those used in
heating steam boilers, which I will henceforth call "the furnace."
Secondly. In a reverberatory furnace or calcining kiln placed between
these furnaces and separated only by a party wall. This furnace or
kiln I will henceforth call "the kiln."
The two furnaces and kiln are constructed parallel to each other,
their fronts being in the same vertical plane. All three are lined
and arched with fire-bricks or other refractory material, and their front
and back walls are in line. On these walls above the arches and
extending back a long distance on walls and pillars in the usual manner
I place a salt or evaporating pan or drying floor, as may be required,
having flues below separated from the furnaces and kiln by the brick
wall. The hinder part of each furnace communicates with the kiln,
and through these communications the products of combustion pass into
the said kiln. After permeating the pile of limestone or ore, or heating
gas retorts, as the case may be, the gases then escape through a slit in
the top of the kiln near the front wall and proceed into the flue under
the pan or drying floor to the other extremity, and thence up the
chimney. Sometimes when the salt pans are thus heated the effluent
products of combustion are passed under the drying floors to still further
utilise the heat.
In order to increase the draught I usually place one or more fire-brick
tubes or flues over the kiln or the party walls (by preference two circular
flues in the latter position), in either of which the gases from the kiln
are drawn (after passing through the slit) by means of a steam jet.
This causes a pressure under the pan slightly greater than that of the
atmosphere. There is thus a constant pressure outward, causing a
splendid draught without the use of a chimney, and entirely preventing
in drauglits of cold air through defective walls.
To prevent the steam jet causing a strong current through the centre
only of the fluc beneath the pan, I place cross walls so arranged as to

page_text: cause a split draught, and make the products of combustion follow a
circuitous course.
The arches over the furnaces may be dispensed with altogether, or
made if desirable with numerous vent holes so as to allow a portion of
the gases to ascend at once and heat that part of the pan above them,
but this is usually not desirable, the main object of the arches being to
preserve the pans from the fierce direct radiant heat of the furnace so
destructive in the arrangements hitherto employed.
One of the chief advantages of this form of apparatus besides the
great economy of fuel which it effects is that by firing the two furnaces
alternately each in turn burns the others smoke as it passes into the
combustion chamber.
Having described the nature of my said Invention, I will now proceed
by the aid of the accompanying Drawings to describe the same more
particularly, and also a mode or method by which the same may be
readily carried into effect, in which said description I have shewn my
apparatus as applied to the manufacture of salt.

page_text: enter the kiln near the bottom, and are thus caused to be more uniformly
distributed throughout the kiln in rising to the front end of the same
where they enter the flues D, D, through a slit or narrow rectangular
opening in the top of the kiln near the front wall. The flues D, D,
communicate at their back ends with the flue or space E underneath
the evaporating pan F, and in order to accelerate the draught through
the flues steam jets G, G, supplied through a pipe G₁ from any con-
venient boiler are introduced into them. Either of the flues D, D, may
be used at pleasure, the other being temporarily closed. I prefer to
have two instead of one central flue so as to have a spare one to use in
case of accidental damage to the other. As the tendency of the steam
jet would be to force the gases in a current of limited width straight
across the flue or space E beneath the pan, leaving the air or gases
almost stagnant on either side, whereby the heat would be applied in a
very imperfect manner to the evaporating pan. I cause the draught to
be diffused as much as possible throughout the flue by forming therein
baffle walls or partitions K, K, as shewn, which cause the gases to take a
circuitous course in the flue. When the gases have traversed the entire
length of the flue E and have thus imparted the greater part of their
heat to the evaporating pan F they are allowed to escape through the
openings L either into the atmosphere or into a chimney shaft, or if they
still contain useful heat they may be further conducted into the flues of
a drying floor or chamber. I prefer to make the salt pan F so large as
that it shall extend forward over the furnaces A and kiln B, in order
that the heat radiated from the arched tops of these may also be utilised.
The salt pan might serve to enclose the furnaces and kiln at top, as
before stated, dispensing with the brick arches; but I prefer to employ
these in order to protect the pan from the fierce direct heat of the
furnaces. H, H, are the handles for draining the salt crystals raked out
of the pan; and I is the brine pipe for supplying the pan with brine.
Having thus described the nature of my Invention, and in what
manner the same is to be performed, I wish it to be distinctly understood
that although I have described my said Invention as applied to the
manufacture of salt that it may be readily applied in other manufactures
in which evaporation by heat is applicable or requisite, and also that the
details of the apparatus herein described may be varied without departing
from my said Invention. And I also wish it to be distinctly understood
that I do not claim any of the parts of the apparatus which I have

page_text: herein described separately or apart from the combination thereof
forming the apparatus herein described, nor do I claim a combination
of a furnace, a combustion chamber, and flue with a steam jet for forcing
the combustion, as I am aware that such a combination has been
described before the date of my Patent, and particularly in the Specifi-
cation of a Patent No. 875, of the year One thousand eight hundred and
seventy-three, dated the Eleventh March, One thousand eight hundred
and seventy-three, and granted to Thomas Bright Wilson; but what I
claim as the Invention secured to me by the hercin-before in part recited
Letters Patent is, the apparatus, substantially as herein described, con-
sisting of two furnaces in combination with a kiln or reverberatory
furnace, a tank evaporating pan or vessel for evaporating liquids, or
vessel or drying floor to be heated, and steam jets and baffle walls or
partitions whereby the flames and gaseous products of combustion are
made to pass from the furnaces into the kilu, and after acting upon the
contents thereof are conducted from thence and forced into and through
flues beneath the evaporating pan or vessel or drying floor,
In witness whereof, I, the said James Thomas Lockey, have
hereunto set my hand and seal, this Twenty-eighth day of
September, in the year of our Lord One thousand eight hundred
and seventy-five.