IMPROVEMENTS IN UTILIZING THE GASES FROM BLAST FURNACES, AND IN THE APPARATUS OR MEANS EMPLOYED THEREIN
Year: 1871

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn
Fields, in the County of Middlesex, Gentleman, for the Invention
of "IMPROVEMENTS IN UTILIZING THE GASES FROM BLAST FURNACES, AND IN
THE APPARATUS OR MEANS EMPLOYED THEREIN."-A communication from
abroad by Jean Emile Arthur B. de Langlade, Forge Master, of
Paris France
Scaled the 20th October 1871, and dated the 7th August 1871.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson
at the Office of the Commissioners of Patents, with his Petition,
on the 7th August 1871.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County
of Middlesex, Gentleman, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN UTILIZING THE GASES FROM BLAST FURNACES,
AND IN THE APPARATUS OR MEANS EMPLOYED THEREIN," a communication to me
from abroad by Jean Emile Arthur B. de Langlade, Forge Master, of
Paris, France, to be as follows:-
:―
This Invention relates to the treatment of the gases evolved from
blast furnaces, and to the application of the same to the heating of

page_text: reverberatory furnaces, and to other heating purposes, also to apparatus
employed therein, and consists essentially in causing the said gases to
pass through a regenerator, such, for example, as Siemens' regenerator,
and in washing and purifying the said gases by causing them before
entering the regenerator to pass through an apparatus specially con-
structed for the purpose, which at the same time ensures the said gas or
gases being supplied to the furnaces where they are to be burned at a
uniform or nearly uniform pressure. The gases may be taken from the
blast furnace in any well known manner; it is preferred however to
employ an annular truncated metal ring let into the furnace, with an
annular passage for the gas round it, which gas enters a brick chamber
provided with a regulating damper. From this chamber an inclined
ascending tube conducts the gas to the top of a vertical descending tube
by which it enters an inverted open mouthed vessel or bell, having its
mouth sealed by dipping in a tank of water, the level of which is
maintained at or about a uniform height in any well-known manner.
An air pipe opening direct into the atmosphere is also fitted to the top
of the inverted vessel, its lower mouth being surrounded by a partition
which dips more or less according to the pressure of gas required into
the water in the tank, any excess of pressure causing the air pipe to be
unsealed, and allowing the superabundant gas to escape into the atmo-
sphere. Or the gas from the blast furnace may be made to pass under a
water sealed partition before it can enter the pipe leading to the
regenerator, hence the pressure must always be sufficient to unseal the
partition, and thus a certain uniformity is maintained. The gas passes
by another pipe from the inverted vessel into a washer, where all dust
and foreign matters are removed, and any steam that may be mixed
with the gas will be condensed. This washer consists of a vertical pipe,
down which a shower of water descends, the said shower not only
washing the gas but also imparting increased velocity thereto, and
ensuring a sufficient pressure. The lower end of the washer opens into
an apparatus constructed on the principle of the Davy lamp for the
purpose of preventing or at least localizing any explosion that might
occur through the admixture of air with the gas. This apparatus
consists of an inverted open mouthed vessel sealed by water in a tank,
and containing a number of closely packed metal bars, over which cold
water is kept constantly flowing. After leaving this apparatus the gas
passes through a Siemens' or other well-known regenerator, and thence

page_text: to the furnace to be heated. If desired the requisite velocity may bẹ
imparted to the gas by the aid of forced air jets placed axially in the
pipe along which the gas passes. When the furnaces where the gas is
to be utilized are situate a considerable distance from the blast furnace
then the artificial condensation and washing of the gas may be dispensed
with, as the condensation of the gas or vapour and the deposit of dust
will naturally take place during the passage of the gas through the long
pipes or passages..
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Henry Johnson in the Great Seal Patent
Office on the 7th February 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Mid-
dlesex, Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventh day of August, in the year
of our Lord One thousand eight hundred and seventy-one, in the
35th year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said John Henry Johnson, Her special
license that I, the said John Henry Johnson, my executors, admi-
nistrators, and assigns, or such others as I, the said John Henry
Johnson, my executors, administrators, or 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,
usc, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN UTILIZING THE GASES FROM BLAST FURNACES, AND IN THE
APPARATUS OR MEANS EMPLOYED THEREIN," a communication to me from
abroad by Jean Emile Arthur B. de Langlade, Forge Master, of Paris, in
the Empire of France, upon the condition (amongst others) that I, the
said John Henry Johnson, my executors or administrators, by an instru-
ment in writing under my hand and seal, 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 the Great
"

page_text: Seal Patent Office within six calendar months next and immediately
after the date of the said Letters Patent.
NOW KNOW YE, that I, the said John Henry Johnson, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement, reference being had to the accompanying
Drawings, and to the letters and figures marked thereon, that is to
say :-
The said Invention has for its object the utilization of the gases from
blast furnaces for the heating of furnaces in general. These gases arc
taken from the mouth of the blast furnace, and after having been pre-
viously deprived of the dust which they carry with them, and of the
greater part of their steam, they are caused to pass into a regenerator,
such, for example, as a Siemens' regenerator, and thence into furnaces
in order to maintain a suitable temperature. By this means the quantity
of fuel only that is absolutely necessary for the operation need be used,
and consequently the loss of heat attendant upon steam boilers may be
avoided by utilizing in those localitics where waterfalls exist hydraulic
motive-power engines, which are much less expensive. The gases may
be employed alone, or if necessary mixed with a certain proportion of
gas obtained from any suitable gas generator.
The furnaces to be heated may be situate either near to or at a
distance from the blast furnaces. In the former case it is necessary to
deprive the gases artificially by condensation and washing of the vapour
and dust they contain; in the latter case the vapour is condensed
spontaneously in consequence of the gases becoming cooled in their
passage from the blast furnace, and the dust is deposited in the conduits.
If artificial washing and condensation are required it is desirable to
direct a shower of cold water into the vertical pipe which conducts the
gases from the mouth of the furnace to the level of the works with the
triple object of condensing the vapours, washing the gases from their
dust, and imparting to them sufficient pressure. The gases after
passing through this pipe are caused to traverse a suitably arranged
condenser, whence they are conducted to the regenerators, and thence to
the furnaces. It will thus be seen that the essential feature of this
Invention consists in the application of the gases from blast furnaces to
regenerative furnaces, also in the apparatus required for purifying the

page_text: gases and regulating their pressure, the object being to conduct them to
the furnaces (where they are to be utilized) in the best condition
for use.
And in order that the 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 Sheet of Drawings,
the same letters of reference indicating corresponding parts in all the
corresponding Figures.
Figure 1 of the Drawings represents in vertical section the general
arrangement of apparatus employed in carrying out this Invention.
F is the blast furnace, and G its mouth. Near the mouth there is
disposed a truncated annular ring a of cast iron, in the interior of which
the charges fall whilst the gases pass outside into a chamber 6, which is
provided with a damper for the purpose of regulating their outlet.
Connected with the chamber 6 is a pipe T which conducts the gases into
the pressure regulating apparatus. This apparatus is composed of an
open tank C containing water, the level of which is maintained constant
by means of a continuous feed and an overflow; over the tank C there is
disposed an inverted receiver or bell C₁ of sheet metal, carrying on the
top three pipes t, t¹, t¹, (shewn more clearly in the plan view thereof at
Figure 2). A partition c separates the part containing the tube from
the other portion of the receiver. The lower edges of the receiver or
bell C¹ dip sufficiently into the water in the tank C to prevent the gases
from passing under its edges. The partition c is so arranged that when
there is no other than atmospheric pressure its lower edge dips for a
certain depth in the water in the tank. This depth, which is regulated
at will by raising or lowering the level of the water in the tank, is equal
to the height of water corresponding to the pressure that it is desired to
impart to the gas in the receiver or bell. The pipe is in communi-
cation with the atmosphere, the other two pipes t and (" respectively
receive the gases which arrive through the pipe T, and those which are
to pass off through the pipe T¹. The gases thus pass without obstacle
from the pipe T to the pipe T. By this means so soon as the pressure
of the gas in the portion of the receiver or bell corresponding to the gas
inlet and supply pipes exceeds the determined point the water will
descend below the edges of the partition c, and allow a portion of the
gas to pass, which will escape into the open air through the exit pipe t',

page_text: and from this moment the pressure will be unable to increase beneath
the bell. A constant pressure of the gas supplied may be ensured by
allowing always a little gas to escape by the exit pipe t'. The same
result may be obtained in another manner, thus, assume an open
tank containing water at a constant level, and a receiver or bell carrying
two pipes on the top, this receiver or bell is placed over the water in
the tank as in the apparatus herein-before described, so that the edges
only of the receiver or bell dip in the water. The two pipes arc
separated from each other by a partition, the edges of which dip in the
water in the tank to a depth corresponding to the pressure which it is
desired to maintain at the gas supply; one of these pipes serves to
introduce the gas from the blast furnace, and the other to conduct it to
the regenerators. In order to pass from one pipe to the other the gas
must necessarily pass under the edges of the partition, its pressure must
then be such as to drive back the water below this partition, otherwise it
could not pass off through the outlet pipe which supplies the gas to the
regenerators whatever exhaustion may be produced beyond the partition.
It will also be necessary to prevent the pressure of the gas exceeding
beyond the partition the pressure that it is desired to maintain at the
supply. In this case where this second apparatus is employed and the
furnaces do not consume all the gas which arrives in the conduit pipes
it will be requisite to provide near the furnaces an apparatus similar to
that firstly hercin-before described with an exit pipe, by this means the
pressure of the gas at the entrance to the regenerators will be regulated
as desired, providing that a compressing apparatus be employed to
impart the desired pressure to the gas. In order to impart a given
pressure to the gas it is proposed to adopt an exceedingly simple
arrangement. The pipe d conducts water from the tank C to a plate f
perforated with holes, and situate in the upper part of the vertical
pipe T. The water thus falls in a shower into this pipe, and conse-
quently carries down along with it the gas at a proportional velocity,
which is regulated at will. At the bottom the water falls and splashes
on a plate g, thus completing the washing of the gases. The pipe T
opens into an apparatus which is intended to prevent or at any rate to
localize explosions resulting from the mixture of air and gas which may
be produced. This apparatus is based upon the principle of the Davy
lamp, it is composed of a tank Q (shown in plan in Figure 3) in which
the level of the liquid is constant, above this tank there is disposed an

page_text: inverted vessel Q' of suitable form, shewn in plan in Figure 3. In a
chamber raised above the vessel Q₁ a number of rows of metal bars M
(composed of wrought or cast iron or other metal) are disposed with
spaces only as small as possible left between them. These bars are
constantly watered by a jet of water J in order to prevent the spaces
between the bars becoming obstructed with the dust which is carried
along with the gases, and also the metal becoming heated, which would
diminish the security which the apparatus is intended to ensure. It
should be observed that the thickness of the layers of bars should be
increased in proportion to the increased size of the spaces left between
the bars. The gases on leaving this latter apparatus pass through the
pipes T and T to the regenerators, whence they are conducted to the
furnaces.
One very simple means of imparting the desired velocity to the gases
when there is a blowing machine at disposal consists in employing a jet
of air placed in the centre of one of the conduits. This plan is equally
efficient in any case where it is required to impart motion to gases, as,
for example, for the purpose of effecting a draught in chimnics or other
similar purposes.
The various apparatus herein-before described may be used separately
or in combination either in conjunction with the improved method of
heating with gases from blast furnaces, or with any other system to
which they may be applicable, and may be arranged in any suitable
order in the passage of the gases.
Having now described and particularly ascertained the nature of the
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 he novel and original, and therefore claim as the Invention secured
to me by the herein-before in part recited Letters Patent is,-
First. The utilization of the otherwise waste gases from blast furnaces
for the heating of furnaces in general or other apparatus by causing the
said gases to pass into a Siemens' or other regenerator.
Secondly. The construction and arrangement of apparatus substantially
as herein-before described and illustrated by the Drawings for the purpose
of obtaining the desired pressure of gas at the supply pipe, and also on
its arrival at the furnaces, the limiting the space in which explosions can

page_text: occur, the washing and purification of the gases prior to their admission
to the combustion apparatus, and the imparting to such gases a given
velocity which may be modified at will.
In witness whereof, I, the said John Henry Johnson, have to this
my Specification set my hand and seal, the Seventh day of 5
February One thousand eight hundred and seventy-two.
J. HENRY JOHNSON. (L.S.)