IMPROVEMENTS IN THE MEANS AND APPARATUS FOR THE MANUFACTURE OF CAUSTIC AMMONIA AND AMMONIACAL SALTS
Year: 1869

page_text: LETTERS PATENT to Frederick Braby, of Fitzroy Works, Euston Road,
in the County of Middlesex, for the Invention of "IMPROVEMENTS IN
THE MEANS AND APPARATUS FOR THE MANUFACTURE OF CAUSTIC AMMONIA AND
AMMONIACAL SALTS."
Sealed the 28th January 1870, and dated the 19th August 1869
PROVISIONAL SPECIFICATION left by the said Frederick Braby at the
Office of the Commissioners of Patents, with his Petition, on the
19th August 1869.
I, FREDERICK BRABY, of Fitzroy Works, Euston Road, in the County
of Middlesex, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN THE MEANS AND APPARATUS FOR THE MANUFACTURE OF CAUSTIC
AMMONIA AND AMMONIACAL SALTS," to be as follows:--
My Invention has chiefly reference to a process for the extrication and
condensation of ammonia described in certain Letters Patent granted
to I. Baggs and F. Braby, bearing date 27 June 1868, No. 2067, and
consists in certain improved means and apparatus for practically carry-
ing out such process.

page_text: For this purpose in one arrangement of apparatus the gas or other
liquor from which the ammonia is to be extracted is introduced together
with lime into a boiler, still, or generator of wrought iron or other
suitable metal set in brickwork, and heated either by means of a fire
underneath, the flames from which are made to pass over a great
portion of its external surface, or by means of hot air or steam pipes
situated inside the still. In this latter method of heating the generator
may be of wood, or of wood lined with metal, or even of cement and
brickwork, or asphalte, or other material. A spindle passes through the
generator armed with a number of beaters or fans constantly kept
revolving in the liquor. Air is forced by means of a force pump, fan,
bellows, or other blowing apparatus into perforated pipes situated inside
the still, the perforations of which increase in number as they are further
from the inlet of air. Through these perforations the air passes in
bubbles among the gas liquor, is caught up by the fans, and in thus
together with the lime being brought into intimate contact with the
various constituents of the gas liquor, namely, water, ammonia, carbonic
dioxide, sulphuretted hydrogen, sulphocyanides, &c., takes up the
ammonia and passes together with the same into the steam or air chest of
the boiler, whence it is conducted through a pipe into a purifier or
washer. This consists of a wooden or iron vessel of comparatively small
capacity containing lime, and being about one-third full of water; it is
closed at the top, and is provided with a perforated false bottom or
diaphragm, the perforations of which increase in size and number as
they radiate from the point at which the air charged with ammonia is
introduced beneath the diaphragm. This purifier is furthermore pro-
vided with a revolving stirrer or agitator having revolving blades above
and below the perforated diaphragm, so as to bring the alkaline vapour
carried by the air into intimate contact with the solution of lime, and
two trial taps fixed at proper heights serve to test for gas and water;
there is also a pipe sealed at one end extending about halfway from the
bottom for conducting away any excess of liquid that may accumulate
by condensation of aqueous vapour coming over from the still with the
alkaline air; lastly, a safety pipe is provided for relieving the washer of
any excess of pressure. Safety and vacuum valves are also provided
to the generator or still. In the washer the ammonia is deprived of any
remaining hydro-sulphuric acid or other impurity that may have escaped
the action of the lime in the still or generator. When the lime in the
washer has taken up so much of such impurities as to lose its efficacy it

page_text: is caused to pass from the washer into the generator through a pipe at
the bottom provided with a tap, and a fresh charge is introduced into
the washer. The air and ammoniacal gas pass from the washer through
a pipe at the top thereof into a coil or worm contained in a cold water
cistern, which coil opens into the bottom of a deep close vessel. about
one-third full of pure cold water or ice, which vessel is provided with one
or more perforated diaphragms, upon which are placed if necessary
shallow layers of pebbles. The air charged with ammonia in bubbling
up through the water, with which it is brought into intimate contact
by passing through the perforations of the diaphragms and through the
layers of pebbles, parts with a certain quantity of the ammonia to the.
water, and on issuing into the space above the same it is conducted
through bent pipes in succession through one, two, or more similar
vessels, the water in which gradually absorbs the whole of the ammonia,
so that from the last of them the air deprived of all the ammonia is
allowed to escape into the atmosphere. The last vessel or receiver may
contain instead of water a strong solution of chloride of iron or sulphate
of iron, which being denser and possessing a higher specific gravity
than water offers a greater pressure and resistance to the passage of the
gas. The iron salt thus produced is decomposed with formation of
muriate of ammonia or sulphate of ammonia in solution, and the
deposition of a sesquioxide of iron, which when calcined and pre-
pared, affords a good pigment. When instead of caustic ammonia it is
desired to manufacture ammoniacal salts, the receivers are charged with
sulphuric or muriatic acid, or a metallic or saline solution capable of
arresting the ammonia. The saturated liquid salt is run from the.
receivers into shallow pans, and is evaporated to the crystallizing point
by means of heat and by means of air blown into the liquid from per-
forated pipes or from below a perforated false bottom.
After all the ammonia has been extracted by the above process from
the charge of gas liquor in the still the contents of the latter are run
off into a draining pit, from which the clear water passes off into a
sewer while the solid inodorous lime compound is carted away. The
sides of this pit are constructed of brickwork lined first with sand and
then with wood, while the bottom is formed of perforated wood resting
upon a layer of sand, beneath which is a layer of gravel, and beneath
this a bed of cement; channels and small drain pipes are provided for
conducting the water to a large central drain pipe leading to the sewer;

page_text: perforated shelves or trays are provided in the draining pit to catch the
solid deposit. To ascertain the exact state of the contents of the boiler
or still first described, and to avoid the necessity of providing taps at
too many levels for this purpose one single tap is provided at the lower
end, to which is attached a short pipe inside the still working easily on
an elbow. To this pipe is connected a copper wire or rod passing out
through a stuffing box in the top or side surface of the still, by which
wire or rod the pipe may be raised or lowered so as to have its orifice
presented at any required level at which it is desired to ascertain the
state of the contents of the still.
In place of forcing the air into the still through perforated pipes as
previously described it may be forced through one, two, or more vertical
pipes between two perforated plates held a small distance apart near
the bottom of the still, the one plate being bent down at the sides so as
to close these, or the plates may extend right across the still so as to
constitute diaphragms. The air forced into the still may either be cold
or it may be previously heated; for the latter purpose it may con-
veniently and economically be forced by the air pump through a series
of small pipes passing through one or more chambers, into which the
exhaust steam from the steam engine working the pumps is intro-
duced, the heat of which steam is thus utilized by being imparted to
the air.
In another arrangement of apparatus the ammoniacal gas liquor
having been first purified by means of lime and by agitation is allowed
to fall through a vertical shaft or oblong chamber provided with a series
of trays or shelves arranged to project alternately from opposite sides of
the shaft, so that the gas liquor in falling has to pass from one tray to
the next below, thus constantly presenting in its downward course a
great and continually changing surface, so that the atmospheric air,
which is forced in from near the bottom of the shaft, in its upward
course passes through and in intimate contact with the falling liquor,
thereby taking up from such liquor the ammonia held in solution
thereby. The before-mentioned shelves may be partially perforated so
as to allow both the air to bubble up through the perforations and the
liquor to drop partially down through the same, thus still further
increasing the contact between the air and liquor. Or in place of such
shelves complete perforated diaphragms may be employed, with or
without overflow pipes leading from above one diaphragm to the next

page_text: below, so that the whole of the air in forcing its way upwards has to
bubble up consecutively through the layers of liquor contained on each
of the diaphragms, and at the same time comes in contact with the
liquor falling down from one diaphragm to another. The ammoniacal
liquor may also be passed through the above-described apparatus with-
out previous purification; in such case the sulphuretted hydrogen and
The
other impurities are disposed of in any other well known manner.
liquor may be passed through the apparatus either in a heated or in a
cold state. The air loaded with the volatile alkali and some aqueous
vapour is conducted through a pipe from the closed top of the apparatus
first into a washer with lime water, and then into receivers of ice water,
acid or metallic or saline solutions, according to the produce desired to
be obtained, as before described in connection with the first arrange-
ment of apparatus.
In a third arrangement of apparatus the gas liquor is introduced
with or without the addition of lime into a large, long, closed vessel,
one part of which is deeper than the other, and contains a revolving
bucket wheel, by means of which the gas liquor is raised from the
bottom of the vessel, and is deposited in a trough, along which it
flows to the other part of the vessel, where it is caused to fall on to the
uppermost of two or more perforated shelves projecting alternately
from opposite sides of the vessel, so that the liquor passes down from
the one to the other of these shelves both by flowing over the edges of
the shelves and by dropping through the perforations. Or perforated
diaphragms may be employed, through the perforations of which the
whole of the liquor has to pass. At the bottom of the shallower part of
the vessel is introduced air under pressure, which in rising up is brought
into intimate contact with the falling liquor, and takes up the ammonia
therefrom, after which it is conducted away to be purified and thence
deprived of its ammonia as in the previous cases. The gas liquor after
falling down through the shelves or diaphragms passes again into the
deeper part of the vessel, where it is again raised by the bucket wheel,
and so on repeatedly until the charge of liquor has been deprived of all
its ammonia. The vessel or generator may if requisite be heated by
means of a fire or by hot air or steam pipes. In this arrangement of
apparatus steam may be introduced in place of air as the medium for
taking up the ammonia from the gas liquor.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Frederick Braby in the Great Seal Patent Office
on the 18th February 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FREDERICK
BRABY, of Fitzroy Works, Euston Road, in the County of Middlesex,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Nineteenth day of August, in the year
of our Lord One thousand eight hundred and sixty-nine, in the thirty-
third year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Frederick Brady, Her special licence
that I, the said Frederick Braby, my executors, administrators, and
assigns, or such others as I, the said Frederick Braby, my executors,
administrators, and 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, use, exercise,
and vend, within the United Kingdom of Great Britain and Ireland
the Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS
IN THE MEANS AND APPARATUS FOR THE MANUFACTURE OF CAUSTIC AMMONIA
AND AMMONIACAL SALTS," upon the condition (amongst others) that I, the
said Frederick Braby, my executors or administrators, by an instru-
ment in writing under my, or their, or one of their hands and seals,
should particularly describe and ascertain the nature of the said In-
vention, and in what manner the same was to be performed, and
cause the same to be filed in the Great 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 Frederick Braby, 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 thereof, reference being had to the accompanying
Drawings, and to the figures and letters marked thereon, that is to
say-
My Invention has chiefly reference to a process for the extrication and
condensation of ammonia described in certain Letters Patent granted
to I: Baggs and F. Braby, bearing date 27th June 1868, No. 2067,

page_text: and consists in certain improved means and apparatus for practically
carrying out such process.
For this purpose in one arrangement of apparatus the gas or other
liquor from which the ammonia is to be extracted is introduced together
with lime into a boiler, still, or generator of wrought iron or other
suitable metal set in brickwork, and heated either by means of a fire
underneath, the flames from which are made to pass over a great portion
of its external surface, or by means of hot air or steam pipes situated
inside the still, or by steam or hot air blown directly into the still. In
this latter method of heating the generator may be of wood or of wood
lined with metal, or even of cement and brickwork or asphaite or
other material. A spindle passes through the generator armed with a
number of beaters or fans constantly kept revolving in the liquor. Air
is forced by means of a force pump, fan, bellows, or other blowing
apparatus into perforated pipes, situated inside the still, the perforations
of which increase in number and size as they are further from the inlet
of air. Through these perforations the air passes in bubbles among
the gas liquor, is caught up by the fans and in thus, together with the
lime being brought into intimate contact with the various constituents
of the gas liquor, namely water, ammonia, carbonic dioxide, sulphuretted
hydrogen, sulphocyanides, &c., takes up the ammonia and passes
together with the same into the steam or air chest of the boiler, whence
it is conducted through a pipe into a purifier or washer. This consists
of a wooden or iron vessel of comparatively small capacity containing
lime, and being about one-third full of water; it is closed at the top
and is provided with a perforated false bottom or diaphragm, the per-
forations of which increase in size and number as they radiate from
the point at which the air charged with ammonia is introduced beneath
the diaphragm. This purifier is furthermore provided with a revolving
stirrer or agitator having revolving blades above and below the per-
forated diaphragm, so as to bring the alkaline vapour carried by the air
into intimate contact with the solution of lime, and two trial taps fixed
at proper heights serve to test for gas and water; there is also a pipe
sealed at one end extending about half way from the bottom for con-
ducting away any excess of liquid that may accumulate by con-
densation of aqueous vapour coming over from the still with the
alkaline air; lastly a safety pipe is provided for relieving the washer of
any excess of pressure. Safety and vacuum valves are also provided

page_text: to the generator or still. In the washer the ammonia is deprived of
any remaining hydrosulphuric acid or other impurity that may have
escaped the action of the lime in the still or generator. When the
lime in the washer has taken up so much of such impurities as to lose
it efficacy it is caused to pass from the washer into the generator through
a pipe at the bottom provided with a tap, and a fresh charge is intro-
duced into the washer. The air and ammoniacal gas pass from the
washer through a pipe at the top thereof into a coil or worm contained
in a cold water cistern, which coil opens into the bottom of a deep
close vessel about one-third full of pure cold water or ice which vessel
is provided with one or more perforated diaphragms upon which are
placed, if necessary, shallow layers of pebbles. The air charged with
ammonia in bubbling up through the water with which it is brought
into intimate contact by passing through the perforations of the dia-
phragms and through the layers of pebbles, parts with a certain quantity
of the ammonia to the water, and on issuing into the space above the
same it is conducted through bent pipes in succession through one, two,
or more similar vessels, the water in which gradually absorbs nearly
the whole of the ammonia, so that from the last of them the air is
allowed to escape into the atmosphere. The water in the receivers is
to be kept very cold by any convenient means, and the blowing of air
through the perforated pipes may be intermittent or discontinued during
a portion of the process. The last vessel or receiver may contain instead
of water a strong solution of chloride of iron or sulphate of iron, which
being denser and possessing a higher specific gravity than water offers
a greater pressure and resistance to the passage of the gas. The iron
salt thus produced is decomposed with formation of muriate of ammonia
or sulphate of ammonia in solution, and the deposition of a sesqui-oxide
of iron which when calcined and prepared affords a good pigment.
When instead of caustic ammonia it is desired to manufacture ammo-
niacal salts the receivers are charged with sulphuric or muriatic acid,
or a metallic or saline solution capable of arresting the ammonia. The
saturated liquid salt is run from the receivers into shallow pans and
is evaporated to the crystallizing point by means of heat and by means
of air blown into the liquid from perforated pipes or from below a per-
forated false bottom.
On Sheet I. of the accompanying Drawings is shewn by way of example

page_text: into practice. Figure 1 shews a longitudinal section of the same; Figure
2 shews a part front elevation in perspective, and Figure 3 shews an
enlarged transverse section of the generator. Similar letters of reference
indicate similar parts in each of the Figures.
A is the generator, into which the gas liquor together with lime or
lime and soda is introduced as before described; it consists of a strong
wrought-iron casing set in brickwork, with a fire-place B and flues C
surrounding it, similar to an ordinary steam boiler. Into this generator
air is forced by means of the air pumps D (worked by the steam
engine. E) through the pipes F passing into the generator, where they
branch to either side, as shewn at F', F¹, and terminate in two longi-
tudinal perforated pipes F2, F2, situated close to the bottom of the
generator. A longitudinal spindle G also passes through the generator,
carrying a number of.beaters G¹ and receiving rotary motion by means
of the external pulley G from the steam engine. By means of these
revolving beaters the heated liquor in the generator is effectually stirred
up so as to bring every portion thereof in contact with the air passing
in through the perforated pipes, which air is thus caused to take up the
ammonia from the liquor and to carry it up into the air space and
dome A¹ thereof. Thence the air charged with ammonia rises through
the pipe H into the purifier or washer I. The generator A has a
recess A at bottom, in which as also at the bottom generally the sedi-
ment is precipitated from the liquor, and from which it is discharged as
hereafter described. In place of heating the generator by means of an
external fire this may be effected by the introduction of steam pipes, or,
steam, or steam and air into it, in which case the generator may, if
desired, be constructed of wood instead of iron. The washer or purifier I
consists of a closed wooden vessel containing lime and water and soda
and having a perforated false bottom I', through which the pipe H con-
ducting the air. descends, so that the air charged with ammonia issues
beneath such false bottom and in rising up through the perforations
thereof is brought into intimate contact with the lime water, and' in
order to effect a still more intimate admixture revolving- stirrers J, J;
fixed to the central spindle J' are arranged above and below the
diaphragm, the spindle J¹ being rotated either by hand or by gearing
from the steam engine: The ammonia being purified by this process, as
herein-before mentioned; rises up together, with the air and passes away
-through the pipe K, whence it descends through the pipes. K1, K¹, to

page_text: near the bottom of the receivers L. These receivers are charged with a
solution of muriate of iron, in which on the entrance of the ammonia a
chemical reaction takes place resulting in the formation of muriate
of ammonia and sesqui-oxide of iron, the air which formed the vehicle
for the ammonia being allowed to escape from the receivers. After the
contents of the receivers have been entirely converted by the above
process they are discharged through pipes (not shewn on the Drawing)
on to the filtering tank M in order to separate the muriate of ammonia
from the oxide of iron, for which purpose the tank is provided with a
perforated false bottom M', upon which is spread canvas or other suit-
able textile fabric, which while it allows the ammoniacal salts to pass
through it retains the oxide of iron. This as it accumulates is removed
with a shovel and is thrown through the sheet N into the calcining
ovens O, O, upon the floors of which heated by fires P, P, underneath,
the oxide is spread out and calcined, after which it may be usefully
employed as a pigment. For facilitating the separation of the ammo-
niacal salt from the oxide of iron water is introduced into the filtering
tank M from the cistern Y. The solution of muriate of ammonia is run
off from the filtering tank M through pipes (not shewn) into the evapo
rating pans Q, Q, (shewn in perspective) heated by fires R underneath,
where the greater part of the water is evaporated, and from which the
solution when sufficiently concentrated is run off through a tap T into
crystallizing pans S, S. Lastly the crystallized salt is removed from
the pans S and packed in barrels U, U.
If it be desired to produce caustic ammonia in place of an ammoniacal
salt, as above described, the air charged with ammonia on issuing from
the washer or purifier I is caused to pass, firstly, into a condensing
worm V, Figure 4, contained in a cistern V₁ filled with cold water, from
which worm the condensed and uncondensed ammonia together with
the air are caused to pass through the pipe W down to the bottom of
the close receiver X containing cold water or ice; this receiver has two
false perforated bottoms X1, X3, the perforations of X¹ being made to
increase in number as their distance from the inlet pipe increases. These
false bottoms are provided if necessary with a shallow layer of pebbles,
as indicated, so that the ammoniacal vapour in rising up through the
perforations and among such pebbles is brought into intimate contact
with the cold water, which absorbes the ammonia from the air; it is
then caused to pass in a similar manner through one or more other con-

page_text: densing vessels of like construction, and finally through a vessel
containing a metallic salt. The receivers are kept very cold by means
of running water or by other known methods. After all, or nearly all,
the ammonia has been extracted from the charge of gas liquor in the
still the contents of the latter are run off into a draining pit from
which the clear water passes off into a sewer while the solid inodorous
lime compound is carted away. The sides of this pit are constructed of
brickwork lined first with sand and then with wood, while the bottom
is formed of perforated wood resting upon a layer of sand, beneath
which is a layer of gravel and beneath this a bed of cement. Channels
and small drain pipes are provided for conducting the water to a largę
central drain pipe leading to the sewer, perforated shelves or trays are
provided in the draining pit to catch the solid deposit. To ascertain
the exact state of the contents of the boiler or still first described, and
to avoid the necessity of providing taps at too many levels, for this
purpose one single tap is provided at the lower end, as shewn at a,
Figure 5, to which is attached a short pipe b inside the still working
easily on an elbow b¹. To this pipe is connected a jointed copper
wire or rod c passing out through a stuffing. box d in the top or side
surface of the still, by which wire or rod the pipe may be raised or
lowered so as to have its orifice presented at any required level at
which it is desired to ascertain the state of the contents of the still."
In place of forcing the air into the still through perforated pipes, as
previously described, it may be forced through one, two, or more vertical
pipes between two perforated plates held a small distance apart near
the bottom of the still, the one plate being bent down at the sides so as
to close these, or the plates may extend right across the still so as to
constitute diaphragms. The air forced into the still may either be cold,
or it may be previously heated; for the latter purpose it may conveniently
and economically be forced by the air pump through a series of small
pipes, passing through one or more chambers, into which the exhaust
steam from the steam engine working the pumps is introduced, the heat
of which steam is thus utilized by being imparted to the air.
In another arrangement of apparatus the ammoniacal gas liquor,
having been first purified by means of lime and by agitation, is allowed
to fall through a vertical shaft or oblong chamber provided with a series
of trays or shelves arranged to project alternately from opposite sides of
the shaft, so that the gas liquor in falling has to pass from one tray to

page_text: the next below, thus constantly presenting in its downward course
a great and continually changing surface so that the atmospheric air
which is forced in from near the bottom of the shaft in its upward
course passes through and in intimate contact with the falling liquor,
thereby taking up from such liquor the ammonia held in solution thereby.
The before-mentioned shelves may be partially perforated so as to
allow both the air to bubble up through the perforations and the liquor
to drop partially down through the same, thus still further increasing
the contact between the air and liquor. Or in place of such shelves
complete perforated diaphragms may be employed with or without over-
flow pipes leading from above one diaphragm to the next below, so
that the whole of the air in forcing its way upwards has to bubble up
consecutively through the layers of liquor contained on each of the
diaphragms, and at the same time comes in contact with the liquor
falling down from one diaphragm to another. The ammoniacal liquor
may also be passed through the above-described apparatus without
previous purification, in such case the sulphuretted hydrogen and other
impurities are disposed of in any other well known manner.
The liquor
may be passed through the apparatus either in a heated or in a cool
state. The air loaded with the volatile alkali and some aqueous vapour
is conducted through a pipe from the closed top of the apparatus, first
into a washer with lime water, and then into receivers of ice water, acid, on
metallic, or saline solutions according to the produce desired to be
obtained, as before described in connection with the arrangement of
apparatus.
Figures 6 and 7, on Sheet II. of the Drawings, shew vertical sections
of two modifications of this description of apparatus. In Figure 6 the
vertical closed shaft or chamber e has a number of superposed
trays f, f, f, f', projecting alternately from opposite sides of the
chamber, upon which trays the gas liquor introduced continuously
through the pipe g descends, passing from one tray to the next below in
the manner indicated. The trays may either be perforated, as at f, f, or
not, in the former case the liquor would also pass partially through such
perforations, as shewn. At the same time air is forced in at the bottom
of the chamber through the pipe h, and and in ascending in the con-
trary direction to the flow of the liquor, as shewn by the arrows, it is
brought into intimate contact with such liquor and takes up the ammonia
therefrom, the air thus charged with ammoniacal vapour escapes through

page_text: the pipe i at the top, which conducts it to a purifier or to a condensing
vessel, as in the previous case. The spent liquor as it collects in the
bottom of the chamber is caused to flow off through the pipe j, and if
necessary a steam pipe k is introduced for heating the liquor and dis-
engaging any remaining ammonia from it. The liquor might also, if
found requisite, be pumped up again to the top of the chamber and be
passed through the same a second time.
The arrangement shewn at Figure 7 only differs from the foregoing
in this, that the trays f, f, extend right across the chamber e, the liquor
being caused to descend from one tray to another partially through
the perforations and partially either through the overflow pipes 1, 1,
arranged at alternate sides of the trays or through central overflow
pipes m (or these may consist of longitudinal slits or openings) covered
by caps n, which in dipping into the liquor upon the tray causes the
air in rising up through the pipes m to pass through the liquor as in-
dicated by the arrows. The air also rises through the perforations in
the trays, and if these perforations are made sufficiently large and
numerous the overflow pipes may be dispensed with.
In a third arrangement of apparatus the gas liquor is introduced with
or without the addition of lime into a large long closed vessel, one part
of which is deeper than the other, and contains a revolving bucket
wheel, by means of which the gas liquor is raised from the bottom of
the vessel and is deposited in a trough, along which it flows to the other
part of the vessel, where it is caused to fall on to the uppermost of two
or more perforated shelves projecting alternately from opposite sides of
the vessel, so that the liquor passes down from the one to the other of
these shelves both by flowing over the edges of the shelves and by
dropping through the perforations. Or perforated diaphragms may be
employed, through the perforations of which the whole of the liquor
has to pass. At the bottom of the shallower part of the vessel is intro-
duced air under pressure, which in rising up is brought into intimate
contact with the falling liquor, and takes up the ammonia therefrom,
after which it is conducted away to be purified, and then deprived of its
ammonia as in the previous cases. The gas liquor after falling down
through the shelves or diaphragms passes again into the deeper part of
the vessel, where it is again raised by the bucket wheel, and so on
repeatedly until the charge of liquor has been deprived of all its
ammonia. The vessel or generator may if requisite be heated by means
of a fire or by hot air or steam pipes. In this arrangement of apparatus

page_text: steam may be introduced in place of air as the medium for taking up the
ammonia from the gas liquor.
The liquor in
Figures 8, 9, and 10 shew respectively a longitudinal section, a
transverse section on line 9, 9, Figure 8, and a transverse section on
line 10, 10, Figure 8, of an apparatus constructed as last described;
o, o', is a closed casing, the bottom of which is somewhat deeper at o'
than at o; in the part o are fixed two perforated trays or diaphragms p,
p', one above the other, on to the upper one of which the gas liquor is
introduced through the pipe q. The liquor falls through the perforations
on to the tray p' below, and thence to the bottom of the chamber, while
at the same time air is forced in through the pipe r, and in passing
through the perforations of the trays is brought into intimate contact
with the falling liquor, being thus caused to take up the ammonia
therefrom, and eventually escaping through the pipe s.
the bottom of the chamber o is heated by the perforated steam pipes t,
the intimate admixture of the liquor with the steam being insured by
means of the revolving beaters u on the shaft u¹ caused to revolve by
means of the external pulley u². By this a further quantity of ammonia
is taken up from the liquor by the steam which rises together with the
air through the perforated trays. Or, as before stated, steam alone may
be employed in place of air to take up the ammonia. The liquor flows
from the chamber o down into the chamber o¹, where it is caught up
by the revolving bucket wheel v, receiving rotary motion by means of
the pulley w, and which raises the liquor up and deposits it in the shoot x,
whence it flows on to the upper perforated tray p. The liquor is thus
made to circulate through the apparatus until it is deprived as nearly as
practicable of all its ammonia, after which the charge is withdrawn
through a pipe y, and a fresh charge is introduced through the pipe q.
Having thus described the nature of my Invention, and in what
manner the same is to be performed, I wish it to be understood that I
do not claim generally the employment of a closed boiler or still, wherein
the ammonia of the gas liquor is taken up by a current of air and is
thereby carried into a second vessel or receiver, as this has already been
mentioned in the Specification to the aforesaid Patent granted to myself
and Isham Baggs, but what I claim under the herein-before in part
recited Letters Patent is,-
'First. The construction and employment of apparatus for the manu-

page_text: facture of caustic ammonia and ammonical salts combined and
operating substantially as herein-before set forth.
Second. The peculiar arrangement and mode of operation of stills or
generators for separating the ammonia from gas or other liquor herein-
before described with reference to Figures 1, 2, 3, and 5, on Sheet I. of
the accompanying Drawings.
Third. The peculiar arrangement and mode of operation of stills or
generators for separating ammonia from gas or other liquor herein-before
described with reference to Figures 6 and 7 on Sheet 2 of the
Drawings.
Fourth. The peculiar arrangement and mode of operation of stills or
generators for separating ammonia from gas or other liquor, herein-
before described with reference to Figures 8 to 10 on Sheet 2 of the
Drawings.
Fifth. The peculiar construction and mode of operation of purifiers
or washers for purifying the ammoniacal vapours herein-before described
with reference to Figure 1 of the Drawings.
Sixth. The peculiar construction of receivers or condensers for con-
densing the ammoniacal vapour herein-before described with reference to
Figure 4 of the Drawings.
In witness whereof, I, the said Frederick Braby, have hereunto set
my hand and seal, this Sixteenth day of February, in the year of
our Lord One thousand eight hundred and seventy.
25 Witness,
JNO. MILLARD.
FREDERICK BRABY. (L.S.)