IMPROVEMENTS IN BLAST FURNACES AND IN APPARATUS CONNECTED THEREWITH
Year: 1876

page_text: LETTERS PATENT to David George Hocy, of Workington, in the County of
Cumberland, Ironmaster, for the Invention of "IMPROVEMENTS IN BLAST
FURNACES AND IN APPARATUS CONNECTED THEREWITH."
PROVISIONAL SPECIFICATION loft by the said David George Hoey at the
Office of the Commissioners of Patents on the 21st August 1876.
DAVID GEORGE HOEY, of Workington, in the County of Cumberland, Ironmaster.
"IMPROVEMENTS IN BLAST FURNACES AND IN APPARATUS CONNECTED THEREWITH."
My Invention relates first to the utilization of the waste gasos of blast furnaces
for the purpose of heating the stoves and boilers employed in connection therewith,
and consists in providing means for causing the said gases to be mixed with air,
which air, according to my Invention, is introduced into the interior of the furnace
through perforations in the platform at the top of the furnace, the said perforations
entering the furnace above or near to the level of the charge or through such
perforations in the body of the furnace itself below the tunnel head, and in like
manner entering the furnace above or near to the level of the charge or through
tubes, pipes, or flues, conducting the said air into the interior of the furnace above
or near to the level of the charge or through perforations provided in the tunnel
head or in the charging doors, the said air being supplied from the blast engine by
means of a tube, pipe, or flue, or where suitable by the said perforations, and others
being left open at the outer end to the external atmosphere. The tunnel head to
be closed at the top by means of a damper of any suitable construction. The gases
after having been acted upon by the air are conducted in an ignited condition to
the stoves and boilers by means of a tube, pipe, or flue, provided with dampers
where necessary for regulating and directing the passage of the said gases.
My Invention relates, secondly, to an improved mode of maintaining the lower
outer portion of a blast furnace cool, and for conducting the vapor arising from the
cooling medium away from the tuyere rooms. According to this part of my
Invention I provide around the lower portion of the furnace a jacket, forming a
chamber below the level of the tuyeres, in which chamber thero is arranged a

page_text: perforated tube or series of perforated tubes through which water is caused to flow
and pass through the perforations on to or against the exterior of the lower portion
of the furnace down which it flows continuously. The vapour from the water is
carried away from the chamber by means of a pipe or pipes, which conduct it into
the atmosphere above the tuyere rooms. I also propose to cool the space imme-
diately surrounding the tuyeres, when necessary or desirable, by providing at that
part a pair of hollow shutters or chambers containing a perforated tube or perforated
tubes, through which water is caused to flow and pass through perforations, as
before described, on to the interior of the shutters when closed against the surfaco
surrounding the tuyeres, thereby maintaining it cool at that part, the vapor arising
from the water being carried away by means of a pipe or pipes in the same manner
to that herein-before described with reference to the other cooling chamber.
My Invention relates, thirdly, to means for drying the air in its passage from
the blast engine through the receiver into the stoves by causing such air before
entering the stoves to pass over or in contact with a layer or layers of chloride of
calcium or other suitable substance or substances containing absorbent properties,
or the absorbent materials may be suspended or arranged in any other convenient
manner.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said David George Hoey in the Great Scal Patent Office on the 21st
February 1877.
DAVID GEORGE HOEY, of Workington, in the County of Cumberland, Iron-
master. "IMPROVEMENTS IN BLAST FURNACES AND IN APPARATUS CONNECTED
THEREWITH.
"
My said Invention relates, first, to the utilization of the waste gases of blast
furnaces and consists in the employment of atmospheric air, which is mixed with
such gases by being introduced into the interior of the furnace above or close to
the surface of the charge, the gases after having been acted upon by the air being
conducted in an ignited condition to the stoves and boilers by means of a tube,
pipe, or flue, provided with dampers where necessary for regulating and directing
the passage of the said gases. When the gases are mixed with atmospheric air in
the manner before mentioned an intenso heat is produced which acts upon the
charge at the upper part of the furnace, and this part of my Invention may be
utilized for that purpose only without subsequently employing such gases for
heating the stoves and boilers.
My Invention relates, secondly, to an improved mode of protecting the lower
outer portion of a blast furnace in order to preserve the structure from the
destroying action of the molten contents, and consists in providing at that part a
jacket forming a chamber or chambers below the level of the tuyeres, and where
necessary or desirable extending to a higher level, in which chamber or chambers
I arrange a perforated tube or series of perforated tubes along and through the
perforations of which water is caused to pass so as to be projected in the form of
spray on to or against the exterior of the lower portion of the furnace down which
it flows continuously. I also protect the space immediately surrounding the
tuyeres when necessary or desirable for the preservation of that part of the
structure under the action of the hot blast and of the desconding products of tho
sinelting by providing at that part a hollow shutter or chamber or a pair of hollow
shutters or chambers containing a perforated tube or perforated tubes along and
through the perforations, of which water is caused to pass so as to be projected in
the form of spray on to or against the interior of the shutter or shutters or chamber
or chambers when closed against the surface surrounding the tuyeres. Any vapour
arising from the water in the chamber or chambers first herein-before referred to,
and also in the hollow shutter or shutters or chamber or chambers secondly herein-

page_text: before referred to is carried away by means of a pipe or pipes and conducted into
the atmosphere above the tuyere rooms.
And in order that my said Invention may be fully understood, I shall now
proceed more particularly to describe the same, and for that purpose shall refer to
the several figures on the annexed two Sheets of Drawings, the same letters
of reference indicating corresponding parts in all the Figures.
Figure 1, Sheet 1, of the accompanying Drawings represents a vertical section of
a blast furnace with my Invention applied thereto; Figure 2, Sheet 2, is a hori-
zontal section of the same taken along the line 1, 2, in Figure 1, with the plate of
the platform removed; Figure 3 is a similar section taken along the lino 3, 4, in
Figure 1, and the remaining Figures are modifications and details, which will be
herein-after referred to.
The gases arising from the charges of blast furnaces are in some cases allowed to
escape into the open air, whereby a considerable waste of fuel takes place. In
other cases means have been adopted for utilizing the waste gases for heating the
stoves and boilers employed in connection with the blast furnaces, but the results
obtained have been imperfect and unsatisfactory in consequence (1) of the gases in
all cases being taken off in a crude and impure state, and (2) of the furnaces being
in some cases closed in at the top against the admission of atmospheric air in order
to take off these crude gases, and the fresh charges as put into the furnace being
thus left comparatively cold and often saturated with moisture, or from other defects
not herein specifically set forth.
The first part of my Invention has for its object the purification of the waste
gases, in order to enable them to be more completely and satisfactorily utilized in
heating the stoves and boilers, as well as in effecting a reduction in the amount of
fuel used in the furnace, together with an increase in the quantity and an improve-
ment in the quality of the iron produced. In order to effect these objects, according
to one mode of carrying out this part of my Invention, I cause the air to be
admitted into the upper part of the furnace immediately above or close to the
surface of the charge through a series of holes, tubes, or nozzles, constructed round
the top of the furnace, and which may be made to communicate directly with the
external atmosphere either through the platform, as shewn at A, Figure 1, or
through the body of the furnace, as shewn by the dotted lines A¹ or Ax, but I
prefer to connect the nozzles, as shewn at A³ (Figures 1 and 2), to an annular tube
or hollow ring B built in and around the upper part of the furnace immediately
below the tunnel head C. The annular tube B communicates by means of pipes D
and D' with the air receiver E, which is connected by a pipe or pipes, not shewn
in my Drawings, with the blast engine, whereby cold air is forced through the
pipes D¹, D, annular tube B, and the nozzles A³, into and amongst the gases as they
are generated, so as to effect their immediate combustion. The ignited gases rising
towards the top of the tunnel head (which is closed by means of a damper Ds of
any suitable construction) are thence conducted by means of a tube, pipe, or flue F
(provided with branches having regulating dampers or valves) to one or more stoves
or heaters G and to the boilers, for the purpose of heating the blast and for generating
steam.
According to another mode of carrying out this part of my Invention I admit the
air into the upper part of the furnace through nozzles H fitted in apertures provided
in the columns I of the tunnel head C between the charging doors I¹, and so
arranged as to direct the currents of air towards the centre of the surface of the
charge, as shewn by the arrows in Figure 1; or I admit the air through per-
forations a in the charging.doors I themselves, and thus secure the additional
advantage of protecting the said charging doors from the action of the heat produced
at the top of the furnaco. In the former case the nozzles H may be connected by
branch pipes to the annular tube B or to a similar annular tube L (as shewn in my
Drawings) arranged above the charging doors, and connected by the pipes M and D'
with the receiver E. I also construct the columns I hollow, that is to say, with a
space 6 between the brickwork or other lining c and the metal or other casing d

page_text: and connect the space b with the tube L by branch pipes e, or with the annular
tube B by branch pipes, shewn by dotted lines, e², so as to cause air to circulate
through the spaces b into the furnace, whereby not only is air supplied to the gases,
but the columns I are protected from the action of the heat produced at the top of
the furnace.
h
Figures 4 and 5, Sheet 2, represent a front elevation and vertical section respec-
tively of one of my improved charging doors for admitting air into the interior of
the furnace. N is a metal or other frame built in the brickwork of the tunnel head,
or forming part of such tunnel head, and provided with ears or lugs O, to which the
charging door I is hinged. This door is made hollow, and the inner face f is per-
forated with holes a for the passage of air into the furnace, which air is admitted into
the space through one of the hinges i by means of a pipe k, communicating through
the branch Z (Figure 1) with the annular tube L. The passage of the air from the
space into the furnace is regulated by means of a plate or valve m, provided with
holes n corresponding with the perforations a in the face plate f, so that by rotating
the plate m more or less by means of the handle o, in order to partially or entirely
cover the perforations, the passage of air may be regulated or entirely cut off as
desired. A spy hole or passage p, fitted with a glass q and cover ?, may be provided
through the boss of the plate m, for the purpose of enabling the progress of the
operations to be observed."
The air inlets in the arrangements herein-before described for admitting air into
the furnace are capable of being worked separately, so that any one inlet may for
the time being be caused to act alone, or any two or more of such inlets may be
in action simultaneously, by opening or closing as required any one or moro (as
the case may be) of a series of stop-cocks or valves with which the inlets are
provided.
In my Drawings I have shewn stop-cocks or valves S applied to the nozzles H
and to the branch pipes Z hercin-before referred to, but it is to be understood that
the nozzles, tubes, and holes employed in the other arrangements are each to be
fitted with a similar stop-cock or valve. When the air is obtained from the receiver
E the supply to the furnace may be entirely cut off when required by closing the
stop-cock or valve t fitted to the pipe D¹, and the amount of supply and pressure
may be regulated by the degree of opening of the said stop-cock or valve, and of the
other stop-cocks or valves respectively. When the air is obtained from the outer
atmosphere the supply to the furnace may be entirely cut off in like manner when
required by closing the stop-cocks or valves with which the inlets are provided, and
the amount of supply may be regulated by the degree of opening of such stop
cocks or valves.
It is obvious that although for the sake of convenience I have illustrated in my
Drawings the various modes herein-before described for admitting air to the waste
gases as being combined in one and the same furnace, yet the arrangements may be
employed separately or in any combination required, and the air employed in the
operation may be taken from one or more of the stoves or heaters by any suitablo
connection if in any case it may be considered necessary or desirable to use hot
instead of cold air.
In carrying out the second part of my Invention, which is illustrated by Figure
1, Sheet 1, and Figures 3, 6, 7, 8, 9, and 10, Sheet 2, I fit to the external lower part
P of the furnace immediately below the tuyeres an annular metal or other jacket Q
forming a chamber or chambers, in the interior of which I arrange a perforated tube
or series of perforated tubes u and I connect it or thein to a water supply pipe vso 5
as to cause water to be projected in the form of spray through the perforations on to
or against the surface of the lower portion of the furnace, down which it flows con-
tinuously, whereby the exterior portion of this part of the furnace is cooled to a
greater or less degree, as circumstances may requiro, in order to protect that
part of the structure from the action of the molten contents. Openings or pas-
sages V are provided at the lower part of the case or jacket Q, by means of
which the water is conducted away from the interior continuously, and a pipe
5

page_text: W extending to any desired height above the tuyere rooms is fitted to the
upper portion of the case or jacket for conveying away any vapour arising
from the water. I also employ at that portion of the exterior of the furnace
immediately surrounding the tuyeres hollow shutters or chambers constructed
either in one piece as shewn in Figures 6 and 7, or in two parts or pairs as
shewn in Figures 8, 9, and 10. These shutters or chambers when in use are
pressed close up against the packing surrounding the tuyeres, and may be ex-
tended over the jams and lintle; they may be fixed temporarily by means of screws
or bolts, Figures 6 and 7, so as to admit of their being readily removed when
required, or they may be hinged to the sides of the recess in which they are fitted,
as shewn at ¹ in Figures 8 and 10, so as to admit of their opening out when re-
quired against the sides of the recess. In the interior of each of the shutters or
chambers I arrange a perforated tube or tubes Y, one end Z of which is connected
by means of a coupling 1 (arranged so as to be capable of being readily uncoupled
when it is required to remove or open out the shutters or chambers) to the water
supply pipe v, which is provided with suitable stop-cocks or valvos (not shewn in
my Drawings) for regulating the passage of the water to the perforated tube or
tubes y. Water is thus supplied from the pipe to the perforated tube or tubes
y, whence it is projected in the form of spray on to or against the interior surface
2 of the shutters or chambers contiguous to the furnace, down which it flows con-
tinuously when the shutters or chambers are closed, whereby that portion of the
furnace against which they are caused to bear is cooled to a greater or less degree as
circumstances may require, in order to protect this part of the structure under the
action of the hot blast and of the descending products of the smelting. The water
is conducted away from the interior continuously by means of an outlet pipe 3
fitted to the lower portion of the shutters or chambers, whilst any vapour
arising from the water is carried away by the pipe w connected by a coupling 4 to
the upper part of the shutter or chamber.
By means of the cooling arrangements above described the drawbacks attendant
upon the ordinary modes of cooling are avoided, as all moisture is kept from enter-
ing the furnace at the tuyere rooms and all danger of explosion is prevented, whilst
at the same time the degree of cooling generally or at any particular part can be
regulated or the supply cut off at will by means of stop-cocks or valves with which
the supply pipe of each chamber is provided.
By the use of the means adopted for the purification of the waste gases in the
manner herein-before described, great heat is brought to operate upon each succes
sive charge of ore which is thus prepared for the process of smelting, and a saving is
consequently effected in the consumption of fuel in the furnace, whilst by reason of
the reduced space occupied by the fuel a larger proportion of ore is operated upon,
so that the quantity of iron produced is increased, and as a large proportion of the
impurities is contained in the fuel, the reduction in the amount of fuel used effects
an improvement in the quality of the iron produced.
My Invention may thus be applied in order to reduce the quantity of fuel used
in the furnace, and to increase the quantity and improve the quality of the iron
produced without utilizing the waste gases for heating the stoves and boilers wher-
ever from any cause it is deemed unnecessary to do so, in which case the furnace
may be worked with an open top.
Having now described and particularly ascertained the nature of my said Invention,
and the manner in which the same is or may be used or carried into effect, I would
observe, in conclusion, that what I consider to be novel and original, and therefore
claim as the Invention secured to me by the herein-before in part recited Letters
Patent, is,―
First. The employment in effecting the utilization of the waste gases of blast
furnaces of atmospheric air which is mixed with such gases by being introduced into
the interior of the furnace above or close to the surface of the charge substantially
as lierein-before described.
Secondly. Protecting the lower outer portion of a blast furnace by the aid of

page_text: water, which is introduced into a perforated tube or tubes enclosed in a jacket,
⚫ forming a chamber or chambers surrounding the lower portion of the furnace, and
is projected in the form of spray through the perforations in such tube or tubes on
to or against the exterior of the furnace, any vapour arising from the water being
conducted from the chamber or chambers by means of an escape pipe or pipes, all 5
substantially as herein-before described.
Thirdly. Protecting the space immediately surrounding the tuyeres by the aid of
water, which is introduced into a perforated tube or tubes enclosed in a hollow
shutter or chamber, or in a pair of hollow shutters or chambers, and is projected in
the form of spray through the perforations in such tube or tubes on to or against the 1
interior of the shutter or shutters, or chamber or chambers, any vapour arising from
the water being carried away by means of an escape pipe or pipes, all substantially
as herein-before described.
In witness whereof, I, the said David George Hoey, have to this, my Specifi-
cation, set my hand and seal, this 17th day of February, One thousand 1
eight hundred and seventy-seven.
D. G. HOEY. (L.S.)