Improvements in the Construction of Furnaces and in the Roofs thereof.
Year: 1884

page_text: Improvements in the Construction of Furnaces and in the
Roofs thereof.
I JOSEPH ELTON BOTT, of 230 Stockport Road, Levenshulme, in the County of
Lancaster, Metallurgical Engineer, do hereby declare the nature of my said
invention of "IMPROVEMENTS IN THE CONSTRUCTION OF FURNACES AND IN THE
ROOFS THEREOF to be as follows:-
"
The object of this invention is to construct a furnace with a minimum quantity
of brickwork sufficient only being required to support the weight of the roof and
prevent loss of heat by refraction, instead of as heretofore providing for the thrust
of an expanding arch against skew-backs. The roof is also so constructed in
removable arched sections that unskilled labor can be used to renew an arch
section even during a metallurgical operation thus saving an immense amount of
time and entirely obviating the enormous expenses incidental to repairing the roofs
of furnaces by means of timber centres and the aid of skilled workmen.
In perforining my invention I construct the side walls of a regenerative chamber
or furnace only sufficiently strong to support the weight of the roof which is so
constructed as to rest upon and not to thrust against the side walls. In this
manner I leave the ends of the roof free to expand and slide on a retaining ledge-
all gases being prevented escaping by means of sand or other loose material strewn
along against the edges of the roof so resting upon the side walls.
In constructing my improved form of roof in removable arched sections I employ
a pair of grip-clamps connected to each other by and at opposite extremities of two
wrought iron tension bars held together laterally by means of studs passing
between and connecting the two together and having loose ferrules mounted upon
the studs to keep the tension bars at the desired distance apart the centre ferrule
of the series carrying a lifting hook. These grip-clamps are pivoted or their
respective pins or fulcrums to the tension bars to the inner sides of which at a
suitable distance therefrom are secured a pair of lugs the upper portion of which
form bearings for a pin or journal which carries a regulating screw. This
screw passes through a suitable boss upon the grip clamp and is controlled by a
lock nut.

page_text: In operation the bricks to form the arched section are laid upon a suitable
former or template, when the tension bars with the grip-clamps are placed in
position the lock nuts upon the regulating screws being now screwed against the
grip-clamps sufficient pressure is exercised against the bricks to securely hold them
in the form of the required arch when the whole may be lifted by the lifting hook
and be placed in position upon the furnace walls. In this manner a roof is capable
of being built up in sections laid side by side-each section being free to expand
and slide its ends on the side walls of the furnace and all leakage being stopped by
the application of the loose sand or other material as aforesaid.

page_text: COMPLETE SPECIFICATION.
Improvements in the Construction of Furnaces and in the
Roofs thereof,
I, JOSEPH ELTON BOTT of 230 Cornwall Terrace Levenshulme,. Manchester in
the County of Lancaster, Metallurgical Engineer, do hereby declare the nature of
my invention of "IMPROVEMENTS IN THE CONSTRUCTION OF FURNACES AND IN
THE ROOFS THEREOF," and in what manner the same is to be performed to be
particularly described and ascertained in and by the following statement :-
The object of this invention is to construct a furnace with a minimum quantity
of bricks sufficient only being required to support the weight of the roof and
prevent loss of heat by refraction instead of as heretofore providing for the thrust
of an expanding arch against skew-backs. The roof is also so constructed in
removable arched sections that unskilled labor can be used to renew an arched
section even during a metallurgical operation thus saving an immense amount of
time and entirely obviating the enormous expenses incidental to repairing the roofs
of furnaces by means of timber centres and the aid of skilled workmen. The
improvements being specially applicable to such as the Siemens-Martin, open
hearth, 'annealing, puddling, reheating glass and other furnaces where the cutting
action of heated gases varies at different parts of the roofs or coverings thereof.
In performing my Invention I construct the side walls of the regenerative
chamber or furnace only sufficiently strong to support the weight of the roof
which is so constructed as to rest upon and not to thrust against the side walls
In this manner I leave the ends of the roof free to expand and slide on a retaining
ledge all gases being prevented escaping by means of sand or other loose material
strewn along the edge of the roof so resting upon the side walls.
On the accompanying drawing Fig. 1 represents a front view and Fig. 2 an end
view of so much of a furnace as is necessary to illustrate my improvements.
In both views AA are the side walls which are constructed only sufficiently
strong to support the weight of the roof .B. This roof B is formed in arched
sections and so as to rest upon the top of and not to thrust against the side walls
all gases and heat being prevented escaping by means of sand or other loose
material C strewn along the edges of the roof so resting upon the side walls.
In constructing my improved form of roof in removable arched sections I employ
a pair of grip clamps or levers DD connected to each other by and at opposite
extremities of two wrought iron tension bars E E. These grip clamps or levers
DD have their fulcra d d at each extremity of the tension bars E E and by
suitable nuts F F and lock-nuts F¹ F¹ serowing upon opposite extremities of a
rod G the clamping jaws D' D' are capable of approaching each other and so of
gripping the bricks arranged in arch form and holding them together to form a
roof section. The grip clamps being thus set and maintained at a suitable angle
for holding and retaining the refractory bricks with the requisite thrust against the
key brick H. In practise the bricks forming a roof section are in the first instance
laid on a suitable former or template when the tension bars E E with their grip
clamps D. D. opened out are placed in position upon them, the necessary pressure

page_text: is then exercised upon the clamp jaws D¹ D' by means of the nuts F F to impart
cohesive pressure to the bricks and so to hold them securely in the form of the
required arch-when the whole may be placed over the furnace in position for
work.
•
As the bricks expand during the progress of heating up a furnace the lock
nuts F F are used to relieve the strain on the tension bars E E and grip clamps
DD whilst each roof section is thus free to expand and in doing so simply slides
its ends on the side walls A-all leakage being prevented by the loose sand C as
aforesaid.
In order to keep the tension bars and thrust rod G parallel and central with the
side bars E I interpose the sufficient spacing ferrules ce between same each ferrule
where required. being clongated as indicated by J. J. and perforated for the
passage of the tension and thrust rod G thus preventing side movement of the
same. Intermediate spacing ferrules K are placed where required according to
the strain of each section. Suitable washers L and L' are interposed between the
nuts F and the clamps D for the purpose of equalising the strain on the said nuts.
Although shewn as applied to an angular roof the tension bars may be curved and
a radial brick arch be employed. It will be seen from the said drawings that each
roof section is quite self sustaining no thrust being exerted on the side walls A of
a furnace and being free to expand and contract without injury to the furnace,
consequently the expansive side plates, brickstaves and other forms of stays
required with the ordinary form of spring roofs are in my invention almost
entirely dispensed with whilst isolated sections subject to excessive wear and tear
can be readily and quickly removed even from a steel melting furnace in full
operation without the danger of losing a charge or having to suspend operations to
make such repairs as would be required to repair an ordinary roof in case of falling
or burning away.
Having thus particularly described and ascertained the nature of my inven-
tion, and in what manner it is to be performed, I wish it to be understood that
I am aware bricks have been bound with cast iron and tightened by means of set
screws, cotters etc for use in puddling and other reverberatory furnaces, also that
entirely removable roofs linve been used for round furnaces-and therefore I do
not claim a removable roof broadly but, what I do claim is
1st The improved construction of furnace with roof formed in arched sections
and capable of sliding upon the side walls substantially as and for the purposes
hereinbefore described.
2nd The employment of tension bars and grip clamps for holding bricks together
in an arched form substantially as and for the purposes hereinbefore described and
illustrated on the accompanying drawing.
Dabad thin 9th do 100K
JOHN G. WILSON,
Agent for the Applicant.