Improvements in Treating Gases from Blast Furnaces, Gas Producers, and Coke Ovens, and in Apparatus therefor.
Year: 1889

page_text: Date of Application, oth NOV., 1889
Complete Specification Left, 5th Aug., 1890-Accepted 6th Sept., 1890
Improvements in Treating Gases from Blast Furnaces, Gas Producers,
and Coke Ovens, and in Apparatus therefor.
We, THE COLTNESS IRON COMPANY, LIMITED, of 109 Hope Street, Glasgow, in the
County of Lanark, North Britain, Ironmasters, and WILLIAM YOUNG, of Priorsford,
Peebles, in the County of Peebles, North Britain, Chemical Engineer, do hereby
declare the nature of this invention to be as follows, that is to say:-
This invention has for its object the treatment of gases from blast furnaces, gas
producers, and coke ovens, with a view to the separation and utilisation of their
constituents in a better and more satisfactory manner than heretofore.
In carrying out the invention the first operation consists in separating from the
gases, whilst still in a highly heated state, the dust which they mechanically carry
from the blast furnace in consequence of the great velocity with which they pass
through the materials in the furnace; and this operation is effected whilst the gases
are still hot, in order that little or no tar may be condensed and associated with the
dust. The separation of the dust in this way greatly facilitates the subsequent
treatment of the gases, diminishes the amount of purification required, and improves
the resulting products. Any suitable arrangement of apparatus in which the velocity
of the gasecus current is, once or oftener, temporarily diminished, to allow of the
deposition of dust, may be used; we, however prefer to employ a vertical cylindrical
domed chamber, lined with brickwork to prevent reduction of temperature, into which
chamber the gases are led tangentially or to one side of the centre, and at some
distance from the top, and from which they pass onwards from the centre of the top
by a pipe or flue. Within the chamber the gases circulate in a vortex and the dust
particles are thrown against the sides and drop thence to the bottom where there is a
water lute or seal through which they can be removed periodically.
The second operation consists in separating from the gases sooty tars which would
tend to choke pipes and apparatus if left to be deposited at a later stage; and this
operation is effected in a manner to facilitate subsequent distillatory processes. At
a later stage watery tar is separated from the gases by cooling and condensation; and
it is this watery tar which is used to separate the sooty tar from the still hot gases
freed from the mechanically suspended dust. The operation may be effected in any
suitable gas scrubbing apparatus; and in such apparatus whilst the sooty tars are
absorbed by the watery tar the heat of the gases evaporates the water, and leaves the
mixed tars in a dry or comparatively dry condition, in which condition they can be
more conveniently and satisfactorily distilled than when they have water mixed with
them. It is proposed to use as the scrubbing apparatus a vertical cylindrical
structure divided internally by horizontal partitions and a central column into a
series of annular chambers. The gases are admitted at the lower part of the structure
and are made to pass up through one chamber after another anil to pass round the
chambers alternately in opposite circular directions, finally passing off by a pipe from
the top. The watery tar is supplied at the top and passes down and through the
chambers in directions opposite to those of the gases and is finally led off from the
bottom. In some of the lower chambers paddles are arranged to rotate rapidly so as
to throw up the watery tar in spray to bring it more into contact with the passing
gases.
The gases leaving the scrubbing apparatus herein before referred to will still contain
the more volatile tar oils and the ammonia, which may be separated from them by
ordinary surface condensing apparatus, the last traces of ammonia being obtained by
washing and scrubbing the gases with water as is done in gas works. Or the gases
may be scrubbed or washed with sulphuric acid to directly obtain the ammonia as
ת!
017

page_text: sulphate. Or the gases may be cooled to a temperature of 100 degrees, Fahrenheit,
to recover the tar and part of the ammonia as ammoniacal liquor, after which the
gases may be passed through or in contact with sulphuric acid to separate the last
traces of ammonia. For this purpose the gases may be passed down through lead or
other suitable pipes dipping a little below the surface of the sulphuric acid in one
vessel or in two or more through which the gases pass in succession. The sulphuric
acid used in this way is afterwards saturated with ammonia by being employed
in the apparatus for absorbing the ammonia distilled off from the ammoniacal
liquor.
EDMUND HUNT,
Applicants' Agent.
COMPLETE SPECIFICATION.
Improvements in Treating Gases from Blast Furnaces, Gas Producers,
and Coke Ovens, and in Apparatus therefor.
We, THE COLTNESS IRON COMPANY, LIMITED, of 109 Hope Street, Glasgow, in the
County of Lanark, North Britain, Ironmasters, and WILLIAM YOUNG, of Priorsford,
Peebles, in the County of Peebles, North Britain, Chemical Engineer, do hereby
declare the nature of this invention and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following statement, that
is to say-
This invention has for its object the treatment of gases from blast furnaces, gas
producers, and coke ovens, with a view to the separation of their constituents in a
better and more satisfactory manner than heretofore.
In carrying out the invention in the case of blast furnaces the first operation
consists in separating from the gases, whilst still in a highly heated state, the dust
which they mechanically carry from the blast furnace, in consequence of the velocity
with which they pass through the materials in the furnace; and this operation is
effected whilst the gases are still hot, in order that little or no tar may be condensed
and associated with the dust. The separation of the dust in this way greatly
facilitates the subsequent treatment of the gases, diminishes the amount of purifica-
tion required, and improves the resuiting products. Any suitable arrangement of
apparatus in which the velocity of the gaseous current is, once or oftener, temporarily
diminished to allow of the deposition of dust may be used.
The second operation consists in separating from the gases sooty tars which would
tend to choke pipes and apparatus, if left to be deposited at a later stage, and this
operation is effected in a manner to facilitate subsequent distillatory processes. At
a later stage watery tar is separated from the gases by cooling and condensation; and
it is this watery tar which is used to separate the sooty tars from the still hot gases,
freed from the mechanically suspended dust. The operation may be effected in any
suitable gas scrubbing apparatus; and in such apparatus whilst the sooty tars are
absorbed by the watery tar the heat of the gases evaporates the water, and leaves the
mixed tars, in a dry or comparatively dry condition, in which condition they
can be more couveniently and satisfactorily distilled, than when they have water
mixed with them.
The gases leaving the scrubbing apparatus hereinbefore referred to will still contain
the more volatile tar oils and the ammonia, which may be separated from them
by ordinary surface condensing apparatus, the last traces of ammonia being obtained
by washing and scrubbing the gases with water as is done in gas works. Or the
gases may be scrubbed or washed with sulphuric acid to directly obtain the ammonia
as sulphate. Or the gases may be cooled to 100 degrees Fahrenheit to recover the
tar and part of the ammonia as ammoniacal liquor; after which the gases may
be passed through or in contact with sulphuric acid to separate the last traces of
ammonia.

page_text: six
The constructive.details of the apparatus used in carrying out the invention may
considerably varied as has already been indicated; we however show on
accompanying sheets of explanatory drawings, and hereinafter describe examples
of apparatus which we believe to be well adapted for effecting the desired operations
in a satisfactory manner.
Figures, 1, and 2, on sheets 1, and 2, of the drawings are vertical and horizontal
Fections of apparatus for separating dust from the hot gases. Figure, 3, on sheet, 3,
is a vertical section, and Figures, 4, and 5, on the same sheet are a plan and a
horizontal section of apparatus for absorbing the sooty tars from the gases by means
of watery tars obtained at a later stage of the operations. Figures, 6, and 7, on
sheets, 4, and 5, are a sectional elevation and sectional plan of additional apparatus
for washing the gases. Figure, 8, on sheet, 6, is a sectional plan, and figures, 9,
and 10, on the same sheet are longitudinal and transverse vertical sections of
apparatus for washing the gases with acid to separate ammonia after they have been
passed through ordinary air-cooled surface condensers. In these drawings the same
reference letters and numerals are used to mark the same or like parts wherever they
are repeated.
The dust separating apparatus shown in Figures, 1, and 2, consists of a vertical
cylindrical domed chamber, A, constructed with an outer casing of iron plates and
ined with firebrick to prevent or diminish reduction of temperature. The
gases are
led into the chamber, A, by a duct, A 1, and opening, A 2, in a tangential direction,
or to one side of the centre and at some distance from the top; and they pass off
from the centre of the top by a pipe or flue, A 3, which descends at one side and dips
into water in a box, A 4, so as to be sealed. At the top of the chamber, A, there is
an opening closed by a light lid, A 5, the edge of which is sealed by dipping into a
suitable liquid in a groove, and which gives easy egress to the gases in the event of extra
pressure being caused by internal combustion. For the same purpose a number of
lightly closed doors, A 6, are provided round the bottom of the structure. The lower
part of the chamber, A, is divided by radial partitions, A 7, which check the motion
of the gases and thereby promote the depositing of the dust from them. The dust
collecting at the bottom is raked out periodically through openings, A 8, provided for
the purpose, these openings being sealed by water which also retains the dust. Within
the upper part of the chamber, A, the gases circulate in a vortex and the dust particles
are thrown against the sides and drop thence to the bottom.
The apparatus for scrubbing the hot gases with the watery tars, and shown in
Figures, 3, 4, and 5, consists of a vertical cylindrical structure, B, made of iron
plates and with angleiron framing; and it is divided internally by horizontal par-
The gases
titions, B 1, and a central column, B 2, into a series of,aunular chambers.
are admitted at the lower part of the structure by a duct, B 3, into the space next
above the lowest of the horizontal partitions, B 1, and are made to pass up into one
chamber after another, and to pass round the chambers alternately in opposite circular
directions, finally passing off by a pipe or duct, B4, from the top. A vertical radial
partition, B5, with openings alternately on each side of it in the horizontal par-
titions, B 1, causes the gases to take the course indicated. The watery tar is supplied
by a pipe, B6, on to the top horizontal partition, B 1, and it flows over the hori-
zontal partitions in directions opposite to those of the gases, passing over a low weir
at the opening in each partition down to the next lower one. The weirs are serrated
to subdivide the watery tar into small streams, and distribute them across the openings.
In some of the lower chambers, paddles, B 7, are arranged to rotate rapidly so as to
throw up the watery tar in spray to bring it the more into contact with the passing
The tar which collects at the bottom of the structure passes away by an
gases.
outlet pipe, B 8. Along with the water evaporated from the watery tars some oil is
also volatilised; and the presence of the water vapor and volatilized oil in the gases is
of advantage in the subsequent condensing processes.
The apparatus shown in Figures, 6, and 7, is for washing the gases with simple
water or with ammoniacal liquor. The apparatus comprises a number of casings. of

page_text: which only parts of one are shown in the figures. The upper part, E, of each casing
is semicylindrical the lower part, F, being rectangular and containing the water or
liquor. The upper part, E, is divided by a longitudinal vertical partition, G, into two
horizontal flues, E 1, G 1, which are divided from the chamber or tank, F, below by
horizontal plates, H, formed with openings, E 2, G 2, along the sides. The gases are
led to the several casings by a transverse duct, J, from which a branch, J 1, conveys
a portion down into the upper casing passage, E 1, ou one side; and the gases are
ultimately led away from the other casing passage, G1, through a branch duct and
main duct like the supply ducts, J 1, and J, but not shown in the figures. On the
underside of the horizontal plate, H, there is formed or fixed a serpentine flange or
depending web, H1, the loweredgeof which is serrated and dips a little below the surface
of the water or liquor in the tank, F. The openings, E 2, and G 2, along the two sides
of the plates, H, are so placed as to communicate with the alternate spaces between
the folds of the serpentine web, H1, and the gas descending through any opening, E 2,
on one side gets into a narrowing space between two folds of the web, H 1, and having
sufficient pressure depresses the water in that space and passes between the serrations
in the bottom edges of the web, H 1, into spaces on each side which last communicate
through openings, G 2, with the passage, G 1, through which the gas passes onwards.
The apparatus partly shown in Figures, 8, 9, and 10, for separating ammonia from
the gases by means of sulphuric acid (which is employed in a suitably diluted state)
comprises a number of elongated horizontal iron casings, C, D, of which two are
shown in Figure, 8, the near one being shown in horizontal section at the right-hand
end. The upper part, C, of each casing is semicylindrical, and the lower part, D, is
rectangular and is lined with lead, the sulphuric acid being made to flow through it.
The gases enter the upper part, C, of each casing by a duct, C1, at one end, and pass
off by a duct, C2, at the other end, but they are prevented from passing directly
through by transverse vertical partitions, C3; and the upper part, C, is divided from
the lower part, D, by horizontal tube plates, D1, which have fixed in them lead
tubes, D2, dipping down into the sulphuric acid. The bottom edges of the lead
tubes, D 2, are serrated to make the gas pass from them through the sulphuric acid in
separate small streams or bubbles. Transverse vertical partitions, D3, divide the
lower part, D, into compartments like those of the upper part, C, these lower par-
titions, D3, being arranged relatively to the upper partitions, C3, so that each lower
compartment communicates by an opening, D 4, with the upper compartment next in
order to that one from which it has received the gas through the set of lead tubes, D 2,
which dip into it. With this arrangement the gases have to pass from compartment to
compartment and through successive sets of the lead tubes; and in this way the action
of the sulphuric acid is made exhaustive and complete. The sulphuric acid is made
to pass through the apparatus in a direction opposite to the general course of the
gases, being led through each of the partitions, D, through inverted-siphon tubes so
that it overflows from the surface in each compartment into the next compartment,
and the acid is in consequence maintainedata proper level in each compartment. The
sulphuric acid used in this apparatus is afterwards saturated with ammonia by being
employed in the apparatus for absorbing the ammonia distilled off from the ammonical
liquor.
In applying the invention to gas producers and coke ovens apparatus similar to
that herein before described may be used the various parts being proportioned to suit
the constituents found in the gases in different cases.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, we declare that what
we claim is :-
1-The improved combination of processes for treating gases from blast furnaces,
gas producers, and coke ovens, wherein the gases are first subjected to a dust-
separating process, next to a scrubbing process with watery tar, and afterwards to
condensing and ammonia-separating processes substantially as herein before described,

page_text: the apparatus employed being substantially such as is shown in the accompanying
drawings.
2-The improved dust-separating apparatus substantially as herein before described,
with reference to Figures, 1, and 2, of the accompanying drawings.
3 The process of, and apparatus for scrubbing the gases with watery tar sub-
stantially as hereinbefore described with reference to Figures, 3, 4, and 5, of the
accompanying drawings.
4 The apparatus for washing the gases with water or ammoniacal liquor sub-
stantially as hereinbefore described with reference to Figures, 6, and 7, of the
accompanying drawings.
5 The apparatus for washing the gases with acid to separate ammonia substantially
as hereinbefore described with reference to Figures, 8, 9, and 10, of the accompanying
drawings.
EDMUND HUNT,
Applicants' Agent.