IMPROVEMENTS IN' PRE- PARING FETTLING FOR PUDDLING FURNACES EMPLOYED IN THE MANUFACTURE. OF IRON OR STEEL
Year: 1879

page_text: LETTERS PATENT to Samuel Thomas and David Thomas, both of Trowell, in
the County of Nottingham, for the Invention of "IMPROVEMENTS IN' PRE-
PARING FETTLING FOR PUDDLING FURNACES EMPLOYED IN THE MANUFACTURE.
OF IRON OR STEEL."
Sealed the 9th January 1880, and dated the 23rd October 1879.
PROVISIONAL SPECIFICATION left by the said Samuel Thomas and David
Thomas at the Office of the Commissioners of Patents on the 23rd October
1879.
SAMUEL THOMAS and DAVID THOMAS, both of Trowell, in the County of
Nottingham. "IMPROVEMENTS IN PREPARING FETTLING FOR PUDDLING FURNACES
EMPLOYED IN THE MANUFACTURE OF IRON OR STEEL."
"
We prepare the fettling by placing a sufficient quantity of cinder or slag together
with lime or limestone in a smelting furnace constructed at the sides, front, and
back of water boshes, a space, being left for a fuel chamber at the back, the top of
the furnace being arched in with firebrick. The fuel chamber is supplied with a
blast of cold air underneath. The bottom of the furnace is composed of one or more
cast iron plates, upon the underside of which jets of cold water play. The top of
these plates are covered with a layer of oxide of iron. The furnace is made hot
before charging it with the cinder and lime; when charged a blast of hot air is.
admitted into the furnace through one or more tuyers until the material is melted.
down to a liquid state. It is then run out into suitable sized boxes to cool
for use.
The water boshes before named have a stream of cold water constantly passing
1

page_text: The walls of the furnace not carried up from the foundations are built upon the
water boshes and are of fire-brick throughout, being also arched in with fire brick.
The water boshes are connected to each other by means of four sets of screwed
tubes and elbows C, one such set being shewn in plan at Figure 1 and in side view
at Figure 2. The top of the covering box is shewn broken away at Figure 1 and
the box removed at Figure 2, for that purpose the outer plates being cast with
openings where the connections are placed. Such openings are closed by covering
boxes C¹ bolted to the plates.
Outside the left end bosh a space is left for a fuel chamber E, a clear passage
being left between the fire bridge E¹ and the end water bosh to allow of the passage
of air between them, such air entering through an orifice E in each of the outer
plates B³ and B¹² at the sides. The outer ends of these plates are flanged and
bolted to the end plate B's, which has an orifice nearly the width of the interior of
the furnace and reaches from above the front end of the fire bars E³ to nearly the
bottom of the ash pit, the said orifice being closed by folding doors, shown at
Figure 4.
The fire bars rest upon the bottom of the fire bridge and two bearers E³, seen
in plan at Figure 1.
The fuel chamber is supplied with a blast of cold air underneath through the
orifices E. The side plates B and B have each a perforation through which fuel
is fed to the fire, each being closed by a door, seen at Figures 2 and 3.
There are
pipes D and D¹ (shewn broken off at Figure 2) screwed into the water boshes; these
pipes are connected above to a main water pipe or supply cistern, from which a
current of cold air circulates through the boshes and passes through pipes D3 at the
back into a two inch bore pipe F of cast metal, from the sides of which bosses
project which are screw threaded to receive branch pipes F¹ of one and a quarter
inch bore pierced with holes through which jets of water escape, each jet impinging
upon the lower side of the plates B forming the bottom of the furnace to keep them
cool; the branch pipes F¹ we prefer should be made of copper to avoid the enlarge-
ment of the jet holes by rusting if made of iron. The pipes F and F are supported
by two bearing bars G, the ends of which are carried by the walls of the furnace.
The outer side plates B6, B7, and an end plate B¹ are bolted to two other plates
B5, B6, enclosing two fourteen inch square flues H, H, and a blast pipe heating
chamber I. These flues are indicated by dotted lines in Figures 1, 2, 3, and 5. Both
flues are horizontal to beyond the centre of the length of the walls of the blast pipe
heating chamber, where they turn upwards and pass through holes in a cast iron
plate K', which is carried by and bolted to four vertical pillars which have their
lower flanges bolted to a foundation plate K. The upper and lower ends of the
vertical pillars instead of being bolted to the plates K and K' may take into sockets
cast in the plates. Above the plate K' both flues join and form one eighteen inch
square flue, which passes horizontally over the whole length of the furnace into a
chimney stack K, which is carried up to a height of forty feet, more or less,
according to circumstances and position.
The chimney stack is built upon a cast iron plate K³ carried by four vertical
pillars secured to a foundation plate K³. The eighteen inch flue is built upon metal
plates, shewn by a dotted line in Figures 2 and 3. These plates lie upon the lower
inner flanges of two inverted T girders L which rest at each end upon the plates
K¹, K³, before mentioned.
A blast of hot air is admitted into the furnace by the following means:- -A blast
supply pipe M may enter the chamber I either at the top side or at the bottom of
the heating chamber, as shewn in the Drawings, where it turns up into a single
socketed chamber M¹, one of which is shewn in section at Figure 7, from which it
passes up and down an inverted U shaped pipe M² into a double socketed chamber M³,
shewn in section at Figure 6, out and through two or more double chambers into
two or more lengths of pipes M*, the stack of pipes being highly heated through
spaces left in the sides of the chamber communicating with the fourteen inch flues,
shown by dotted lines at Figures 1, 2, 3, and 5, which are embedded in brickwork

page_text: below the bottom of the eighteen inch flue carried by the girders before named.
The end of the pipes M* terminate in a socket to receive one end of a four way
socket pipe M, the three other ends of which receive the horizontal ends of three
pipes M, each of which turn downwards and terminate in a blast box M', one at
each side of the furnace and one at the left or fire grate end, as shewn at Figures 1;
2, 3, and 4, each pipe being provided with a throttle valve of the usual construction.
Each blast box is bolted to the outer plates, and each covers eight holes cast or
otherwise formed in the plates and carried through the brickwork. The flanges of
the outer plates are not cast on them where the blast boxes are bolted to them.
The socket pipe Ms has in addition four sockets M³ on its underside to receive short
pipes through which hot blast is admitted through the crown of the furnace.
An underside view of the socket pipe M5 is shewn at Figure 9. The end pipe M6
passes through the chimney stack below the flue. Instead of directing the hot
blast into the chimney stack we may employ it to generate or to assist in generating
steam.
3
The materials to form the fettling are fed into the body of the furnace through
three openings N, one at the front which is shewn with the door raised, and two at
the back which are shewn with the doors down; these doors are raised by means
of chains and levers in the usual way.
We do not confine ourselves to the relative forms and dimensions of fuel chamber,
blast pipe, heating chamber, and flue, as we may vary them according to the size and
position of the furnace required.
In a furnace so constructed we prepare fettling in the following manner:-The
bottom of the furnace formed by the top side of plates B and the inner sides of the
water boshes we line with a layer of oxide of iron two inches more or less in
thickness while the furnace is cold. The furnace is then heated and charged with
cinder or slag and lime or lime stone in about equal quantities. The cinder
employed may include bosh dirt, that is, the cinder and oxide of iron knocked off
puddlers' tools. The fuel chamber is kept well supplied with fuel, and the hot blast
being turned on until the charging is brought to a fluid state, the refuse cinder and
silica rising to the surface under the intense heat. The liquid may then be run
into moulds of suitable shapes to be employed for lining, heating, or puddling
furnaces.
Having thus fully described our said Invention and the manner of performing
the same, we declare that we claim the employment of cinder slag or bosh dirt with
lime or limestone to produce fettling suitable for lining puddling furnaces employed
in the manufacture of iron or steel, substantially as hereinbefore described.
In witness whereof, we, the said Samuel Thomas and David Thomas, have
hereunto set our hands and seals, this Thirteenth day of April, in the
year of our Lord One thousand eight hundred and eighty.
SAMUEL THOMAS. (L.S.)
DAVID THOMAS..
(L.S.)