Improvements in Regenerative Gas Heated Crucible Melting Furnaces.
Year: 1898

page_text: Date of Aplication, 28th Mar., 1898
Complete Specification Left, 28th Dec., 1998-Accepted, 28th Jan., 1899
PROVISIONAL SPECIFICATION.
Improvements in Regenerative Gas Heated Crucible Melting
Furnaces.
I, WILLIAM KIRKHAM, of 22, Brinsworth Street, Attercliffe, Sheffield, in the
County of York, Furnace Builder and Contractor, do hereby declare the nature of
my said invention to be as follows:-
My invention relates to improvements in the arrangement and construction of
crucible melting furnaces which are heated by the combustion of gaseous fuel and
which are provided with regenerators.
Firstly, the object of my invention is to construct a melting furnace so that the
crucible or melting pot can be drawn horizontally therefrom instead of vertically
as is the common practice in such furnaces. The advantage in so constructing the
furnace being that the crucible can be withdrawn by means of a pair of trolley
tongs on wheels and thereby a heavier crucible can be handled and a saving of
time effected.
Secondly, to construct a regenerative gas heated crucible furnace with the
regenerating chambers above ground and more accessible for repairs than is the
case where the ordinary practice is followed of building the regenerators below the
furnace and below the floor level.
Thirdly, to construct such a furnace or series of furnaces so that each melting
chamber can be worked and controlled independently of its neighbouring furnace
or of any other furnace in the same group.
Fourthly, to lessen the expense in the construction of crucible melting furnaces
by dispensing with the cellaring and vaults such as are necessary to the ordinary
type of furnace.
carry out my invention in the following manner:
As is customary in furnaces of this type I build a number of melting chambers
(or holes as they are commonly called) in line, each chamber being constructed
to hold one, two or more pots as may be required and as each furnace with its
regenerators and flues will be similar in construction a description of one such
furnace or melting chamber will suffice.
The bed of the furnace I make a sufficient height above the ground line to allow
of the trolley tongs to be conveniently manipulated in gripping and moving the
crucible pot.
The heating chamber I construct with rectangular sides and an
arched roof, the door or opening being placed and hung conveniently for opening
the furnace at the front. On each side of this chamber I form two passages or
ports communicating with vertical or diagonal passages or flues which lead upwards
to two regenerative chambers, one gas and one air regenerator being on one side
above the furnace, and one gas and one air regenerator being on the other side
above the furnace. The two gas regenerators being above the furnace to the
front, and the two air regenerators being above the furnace at the back. Between
one gas and one air chamber on one side and between one gas and one air
chamber on the other side I place a central downcast waste flue which communi-
cates along the back of the furnace with an horizontal flue running the full length
of the furnaces to the chimney stack.
Above the two gas regenerators I fix a reversing valve by means of which the

page_text: flow of the unburnt and waste gases are regulated, first through the regenerator
on one side of the furnace, to the regenerator on the other side, and above the air
regenerators I fix a similar reversing valve by means of which the flow of fresh
air and waste gases are similarly regulated, these reversing valves being connected
with the gas mains and air mains respectively.
The action of my improved furnace is as follows:
By means of the reverse valves the gas and air from their respective mains is
allowed to flow, first down their respective regenerators on one side of the furnace,
thence through their respective passages or ports until they meet in the combustion
or melting chamber herein previously called the furnace, where they are ignited
and by their combustion heat up the furnace and its contents.
The waste gases
then leave the furnace through the ports on the opposite side to that to which they
entered the furnace, passing upwards and through the two other regenerators
thence down the waste gas flue which is placed between the two pairs of
regenerators to the horizontal flue leading to the chimney.
After the waste gas has flowed in this direction for sufficient time to heat up
the checker bricks in the regenerators the direction of the air and unburnt gas
and of the waste gases is reversed so that the incoming air and gas now pass
down their respective freshly heated regenerators to the furnace at a very high
temperature which insures their more perfect combustion in the furnace or melting
chamber. These burning gases make their exit through the ports, passages, or
regenerators in the opposite direction to that first described and so on alternating
from one side to the other as may be required for the regulation of the temperature
of the furnace.
As a modification of the arrangement herein described I sometimes place the
regenerator chambers above the ground line at the back or behind the furnace
instead of immediately above it, and I sometimes arrange two rows of melting
furnaces back to back with blocks of regenerators placed between them. The
regenerator chambers being arranged to work either to one furnace only or with
two or more, furnaces on what may be called the co-operative system.
I am aware that melting and heating furnaces have been constructed with
regenerator chambers above instead of below the furnace and I lay no claim to
novelty in this respect neither do I claim any novelty in the working of a gas
heated furnace in conjunction with regenerative chambers, the essential features
of my invention being the particular arrangement and construction of a gas heated
crucible furnace with regenerators and flues which can be built either singly or
side by side or back to back in a row or rows and so arranged that the temperature
and working of each furnace or melting hole can be regulated independently and
the crucible or melting pot or pots withdrawn horizontally therefrom instead of
vertically as is the common practice in such furnaces, substantially in the manner
and for the purposes as herein described.
Dated this 26th day of March 1898.
R. HEBER RADFORD,
Agent for the Applicant.
Improvements in Regenerative Gas Heated Crucible Melting
Furnaces.
I, WILLIAM KIRKHAM, of 22, Brinsworth Street, Attercliffe, Sheffield, in the
County of York, Furnace Builder and Contractor, 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:-
-
My invention relates to improvements in the arrangement and construction of

page_text: crucible melting furnaces which are heated by the combustion of gaseous fuel and
which are provided with regenerators.
Firstly, the object of my invention is to construct a melting furnace so that the
crucible or melting pot can be drawn horizontally therefrom instead of vertically
as is the common practice in such furnaces. The advantage in so constructing the
furnace being that the crucible can be withdrawn by means of a pair of trolley
tongs on wheels and thereby a heavier crucible can be handled and a saving of
time effected.
Secondly, to construct a regenerative gas heated crucible furnace with the
regenerating chambers above ground and more accessible for repairs than is the
case where the ordinary practice is followed of building the regenerators below the
furnace and below the floor level.
Thirdly, to construct such a furnace or series of furnaces so that each melting
chamber can be worked and controlled independently of its neighbouring furnace
or of any other furnace in the same group.
Fourthly, to lessen the expense in the construction of crucible melting furnaces
by dispensing with the cellaring and vaults such as are necessary to the ordinary
type of furnace.
The nature of my invention will be better understood on reference to the
accompanying sheet of drawings, in which,
Fig. 1, is a sectional elevation of one of my
on the lines, A, B, and C, D, Figs. 2, 3, and 5.
improved melting furnaces taken
Fig. 2, is a plan of the same partly in section, taken on the line E, F, Figs. 1
and 4.
Fig. 3, is a plan in section on the line G, H, Figs. 1 and 4.
Fig. 4, is a front elevation.
Fig. 5, is a plan in section, taken on the line I, J, Figs. 1 and 4.
Fig. 6, is a plan in section taken on the line, K, L, Figs. 1 and 4.
Fig. 7, is a cross section on the line, M, N, Figs. 1, 2, 3, 4, 5 and 6.
Fig. 8, is also a cross section on the line O, P, Figs. 1, 2, 3, 4, 5 and 6.
The same letters refer to similar parts throughout the several views.
carry out my invention in the following manner:
As is customary in furnaces of this type, I build a number of melting chambers
(or holes as they are commonly called) in line, each chamber being constructed
to hold one, two or more pots as may be required, and as each furnace with its
regenerators and flues will be similar in construction a description of one such
furnace or melting chamber will suffice.
The bed of the furnace I make a sufficient height above the ground line to allow
of the trolley tongs to be conveniently manipulated in gripping and moving the
crucible pots, a, a.
The heating chamber, b, I construct with rectangular sides
and an arched roof, the door or opening, c, being placed and hung conveniently
for opening the furnace at the front. On each side of this chamber, b, I form two
passages or ports, d, d, communicating with vertical or diagonal passages or
flues, e, e, which lead upwards to two regenerative chambers, one gas and one air
regenerator being on one side above the furnace, and one gas and one air regene-
rator being on the other side above the furnace. The two gas regenerators, f, f,
being above the furnace to the front, and the two air regenerators, f¹, f¹, being
above the furnace at the back. Between one gas and one air chamber on one side
and between one gas and one air chamber on the other side, I place a central
downcast waste flue, g, g¹, which communicates along the back of the furnace with
an horizontal flue, h, running the full length of the furnaces to the chimney stack.
Above the two gas regenerators, f, f. I fix a reversing valve, i, by means of
which the flow of the unburnt and waste gases are regulated, first through the
regenerator on one side of the furnace, to the regenerator on the other side.
5 and above the air regenerators, f¹, fi, I fix a similar reversing valve, j, by means
of which the flow of fresh air and waste gases are similarly regulated, these

page_text: reversing valves being connected with the gas mains, k, and air mains, l, respec-,
tively. Figs. ī and S.
The action of my improved furnace is as follows:
...!
By means of the reversing valves, i and j, the gas and air from their respective
mains, k and 7, is allowed to flow first down their respective regenerators, f, f',
on one side of the furnace, thence through their respective passages or ports, c, d,
until they meet in the combustion or melting chamber, b, herein previously called the
furnace, where they are ignited and by their combustion heat up the furnace and
its contents. The waste gases then leave the furnace through the ports, d, e,
on the opposite side to that to which they entered the furnace, passing upwards
and through the two other regenerators, f, f, thence down the waste gas flue, g,
which is placed between the two pairs of regenerators to the horizontal flue, h,
leading to the chimney.
After the waste gas has flowed in this direction for sufficient time to heat up the
checker bricks, m, in the regenerators f, f', the direction of the air and unburnt gas
and of the waste gases is reversed so that the incoming air and gas now pass down
their respective freshly heated regenerators to the furnace at a very high
temperature which insures their more perfect combustion in the furnace or melting
chamber. These burning gases make their exit through the ports, passages, or
regenerators in the opposite direction to that first described and so on alternating
from one side to the other, as may be required for the regulation of the temperature
of the furnace.
As a modification of the arrangement herein described I sometimes place the
regenerator chambers above the ground line at the back or behind the furnace
instead of immediately above it, and I sometimes arrange two rows of melting
furnaces back to back with blocks of regenerators placed between them. The
regenerator chambers being arranged to work either to one furnace only, or with
two or more, furnaces on what may be called the co-operative system.
I am aware that melting and heating furnaces have been constructed with
regenerator chambers above instead of below the furnace and I lay no claim to
novelty in this respect, neither do I claim any novelty in the working of a gas
heated furnace in conjunction with regenerative chambers.
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. The particular arrangement and construction of a gas heated crucible furnace
with regenerators and flues which can be built either singly, or side by side, or
back to back, in a row or rows, and so arranged that the temperature and working
of each furnace or melting hole, can be regulated independently, and the crucible
or melting pot or pots withdrawn horizontally therefrom, instead of vertically, as
is the common practice in such furnaces, in the manner and for the purposes sub-
stantially as herein described and illustrated in the accompanying sheet of drawings.
2. In regenerative gas heated crucible melting furnaces, constructing two rows
of furnaces as described in Claim 1, placed back to back, with blocks of regene-
rators placed between them, so arranged to work two or more furnaces on what
may be called the co-operative system in the manner and for the purposes sub-
stantially as herein described.
Datad this 04th dow of Doomhar 1808
R. HEBER RADFORD,
Agent for the Applicant.