Improvements in Certain Apparatus for the Distillation of Ammoniacal Liquor.
Year: 1893

page_text: Date of Application, 12th Apr., 1893
Complete Specification Left, 12th Feb., 1894-Accepted, 3rd Mar., 1894
PROVISIONAL SPECIFICATION.
Improvements in Certain Apparatus for the Distillation of
Ammoniacal Liquor.
We, FRANCIS MUDIE SPENCE, and DAVID DICK SPENCE both of the
Manchester Alum Works, Manchester, in the County of Lancaster Chemical
Manufacturers, and JOHN GILCHRIST of Lyndhurst, Upper Chorlton Road,
Manchester, in the County of Lancaster, Works Manager, do hereby declare the
nature of this invention to be as follows:-
:-
Our invention consists in improvements in the form of the apparatus now
sometimes used for the distillation of ammoniacal liquor and composed of a vertical
iron still or column containing a series of horizontal iron shelves or diaphragms
placed at such a distance apart from each other as to leave an ample steain and
liquor way between them. In the said apparatus three sides or edges of each
shelf or diaphragm are joined to the walls of the column. The remaining side of
each shelf or diaphragm is left free and is kept at such a distance from the wall of
the column as to afford a free passage, or way for steam and liquor. The liquor to
undergo distillation either heated beforehand by waste heat or without being
previously heated is introduced continuously at the top of the still and falls from
shelf to shelf till it finally passes out at the bottom of the still. The opening or
way in any one shelf or diaphragm is always placed at the side of the column
opposite to the opening in the shelf or diaphragm next to it so as to compel the
descending liquor and the ascending steam to traverse as great a distance as
possible and thus expose to each other the maximum amount of contra-current
surface obtainable in a square column.
Our improvements consist :-
Firstly, in making the column oblong instead of square so as to greatly increase
the length of contra-current traverse between any two openings; an oblong still
with shelves or diaphragms of the same superficial area as those of a square one
giving a much longer contra-current traverse than one of the latter form.
Secondly, in providing each shelf or diaphragm of the still with a lip at the end.
or edge next to the opening for steam and liquor and thus securing at all times a
thin stratum of liquor over the whole surface of the shelf or diaphragm.
Thirdly, in providing in each end of the column or still a series of manholes or
openings for cleaning the shelves or diaphragms, every manhole or opening being
placed opposite the lip of a shelf or diaphragm and thus enabling free access to be
obtained, whenever requisite to the upper surface of each shelf or diaphragm and
also. to that of the shelf or diaphragm below it.
Fourthly, in so constructing the still as to enable us to boil off in it the ammonia
both of the fixed and the volatile salts of ammonia present in the liquor.
In the already described still hitherto employed the whole of the diaphragms or
shelves are used to distil off the volatile salts of ammonia and the boiled liquor
passes from the bottom of the still into one of two horizontal stills which work by
turus in conjunction with the vertical still. When one of the two horizontal stills
has received a charge of liquor the. cock supplying it is closed, a quantity of milk
of lime sufficient to decompose the fixed salts of ammonia which the liquor contains
is then introduced into it, steam is turned on to boil off the animonia and the now
ammoniacal steam is passed into the bottom of the vertical still to drive off the
volatile salts of ammonia contained in the descending liquor as already mentioned.
Whilst the charge of liquor in the horizontal still just referred to is being boiled
the liquor from the vertical still is being passed into the second horizontal one.

page_text: When the second one has received its proper charge of liquor and its dose of milk
of lime, and the charge of liquor in the first one has been sufficiently boiled, the
steam is diverted from the first one into the second. The spent liquor of the first
horizontal still is then rapidly discharged, its waste pipe is next closed, liquor from
the vertical still is again diverted into it and so on. In the case of a still
constructed according to our invention a number of the uppermost diaphragms or
shelves only are, employed to boil off the volatile salts of ammonia and the
remaining ones below them are used to distil off the ammonia of the fixed salts.
Our improvements further consist :-
Fifthly, in providing the first of the lower series of diaphragms or shelves with a
considerably deeper lip than is given to any of the diaphragms or shelves above or
below it. This ensures its holding at all times a considerable store of liquor.
Above this diaphragm or shelf we introduce the milk of lime and we thus.secure
its coutinuous mixture with the body or store of descending liquor retained by the
deep lip. The mixed liquor passes over the deep lip on to the several diaphragms
or shelves below it where it is exhausted or practically exhausted of its remaining
ammonia by the upward current of steam which it meets on its way to the bottom
of the column or still.
Sixthly, in providing near the closed end of the highest of the upper diaphragms
or shelves a lip of such depth as will retain behind it sufficient liquor to immerse
the mouth of the ammoniacal liquor supply-pipe and thus protect it from the
injurious action of the gases in the still and also ensure the spreading of the liquor
across the whole width of the diaphragm or shelf.
Dated this Eleventh day of April 1893. '
HOWARD
CHEETHAM,
Manchester, Agent to the Applicants.
Improvements in Certain Apparatus for the Distillation of
Ammoniacal Liquor.
We FRANCIS MUDIE SPENCE and DAVID DICK SPENCE both of the
Manchester Alum Works, Manchester in the County of Lancaster, Chemical
Manufacturers, and JOHN GILCHRIST, of Lyndhurst, Upper Chorlton Road,
Manchester in the County of Lancaster Works Manager 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 :—
Our invention consists in improvements in the form of the apparatus now
sometimes used for the distillation of ammoniacal liquor which apparatus as
hitherto used is composed of a vertical iron still or column containing a series of
horizontal iron shelves or diaphragms placed at such a distance apart from each
other as to leave an ample steam and liquor way between them. In the said
apparatus three sides or edges of each shelf or diaphragm are joined to the walls
of the column. The remaining side of each shelf or diaphragm is left free and is
kept at such a distance from the wall of the column as to afford a free passage or
way for steam and liquor. The liquor to undergo distillation either heated before-
hand by waste heat or without being previously heated is introduced continuously
at the top of the still and falls from shelf to shelf till it finally passes ont at the
bottom of the still. The opening or way in any one shelf or diaphragm is always
placed at the side of the column opposite to the opening in the shaft or diaphragm
next to it so as to compel the descending liquor and the ascending steam to traverse
as great a distance as possible and thus expose to each other the maximum amount
of contra-current surface obtainable in a square column.
Our improvements consist :-
Firstly, in making the column oblong instead of square so as to greatly increase

page_text: the length of contra-current traverse between any two openings; an oblong still
with shelves or diaphragms of the same superficial area as those of a square one
giving a much longer contra-current traverse than one of the latter form. The
advantages we thus secure are two fold-
(a.) By lengthening the total contra-current traverse we make practicable the
more complete exhaustion of the descending liquor by a given quantity of
ascending steam, whilst at the same time we are enabled to deliver stronger
ammoniacal gas or vapour at the gas exit of the still and in this way to
economise steam.
(b.). By lessening the width of the stratum of liquor passing along the
diaphragms it follows that we deepen and proportionately increase the
speed of its current and thus directly lessen the tendency of the lime to silt
and accumulate on the shelves or diaphragms used for lime liquor as will be
hereinafter described. In this way the accelerated current assisted only by
the ebullition caused by the giving off of the ammonia gas enables us to
completely overcome the tendency to deposit lime upon these lime liquor
diaphragms and thus to obviate the necessity either of the objectionable
bubbling valves or openings in the diaphragms or of the bulky sloping,
curved or other inclined surfaces now employed in so many stills to secure
the constant suspension of the lime in the liquor.
In the case of our still the only precautions necessary to secure this result are
the use of properly prepared milk of lime and the previous thorough boiling off
of the volatile salts of ammonia in the upper series of diaphragms described
below.
Secondly, in providing each shelf or diaphragm of the still with a lip at the end
or edge next to the opening for steam and liquor and thus securing at all times a
thin stratum of liquor over the whole surface of the shelf or diaphragm.
Thirdly, in providing in each end of the column or still a series of manholes or
openings large enough to admit of the free use of rakes or shovels for removing
any pitchy or other matter which may be deposited upon the shelves or diaphragms,
every manhole or opening being placed opposite the lip of a shelf or diaphragm
and thus enabling free access to be obtained, whenever requisite, to the upper
surface of each shelf or diaphragm and also to that of the shelf or diaphragm
below it. Every manhole is provided with a lid and cross bar.
•
Fourthly, in so constructing the still as to enable us to boil off in it the
ammonia both of the fixed and the volatile salts of ammonia present in the liquor.
In the already described still hitherto employed the whole of the diaphragms or
shelves are used to distil off the volatile salts of ammonia and the boiled, liquor
passes from the bottom of the still into one of two horizontal stills which work by
turns in conjunction with the vertical still. When one of the two horizontal stills
has received a charge of liquor the cock supplying it is closed, a quantity of milk
of lime sufficient to decompose the fixed salts of ammonia which the liquor
contains is then introduced into it, steam is turned on to boil off the ammonia and
the now ammoniacal steam is passed into the bottom of the vertical still to drive
off the volatile salts of ammonia contained in the descending liquor as already
mentioned. Whilst the charge of liquor in the horizontal still just referred to is
being boiled the liquor from the vertical still is being passed into the second
horizontal one.
When the second one has received its proper charge of liquor and
its dose of milk of lime, and the charge of liquor in the first one has been
sufficiently boiled, the steam is diverted from the first one into the second. The
spent liquor of the first horizontal still is then rapidly discharged, its waste pipe is
next closed, liquor from the vertical still is again diverted into it and so on.
In the case of a still constructed according to our invention a number of the
uppermost diaphragms or shelves only are employed to boil off the volatile salts of
ammonia and the remaining ones below them are used to distil off the ammonia of
the fixed salts. In the case of the distillation of the ordinary ammoniacal liquor
of the gas works we find it desirable to have two or three more diaphragms in the

page_text: •
lower series than in the upper series but the relative number will necessarily depend
upon the proportions of volatile and fixed salts of ammonia present in the liquor.
Some liquors may contain scarcely any volatile ammonia, and some may contain
scarcely any fixed salts of ammonia. We therefore do not restrict ourselves to
any given relative proportion in the number of the upper and lower series of
diaphragms but vary them with the variations in the character of the liquor to be
distilled.
Similarly we do not restrict ourselves to the precise height or dimensions of the
oblong still shown in the accompanying drawings, as it is obvious that in the case of
some liquors a still of greater height and having more diaphragms would with the
same quantity of steam allow of the distillation of a larger quantity than would a
still of the dimensions we have figured.
The quantity distilled will also differ with the different product to be
manufactured as for example whether concentrated ammoniacal liquor or sulphate
of ammonia is to be produced..
In a still of the moderate dimensions shown in the accompanying drawings we
are enabled if manufacturing sulphate of ammonia to distil continuously about one
thousand gallons per hour of the ordinary ammoniacal liquor of the gas works
provided that such liquor has been previously continuously heated by the waste
gases given off from the "absorber."
Our improvements further consist :-
:-
Fifthly, in providing the first of the lower series of diaphragm's or shelves with
a considerably deeper lip than is given to any of the diaphragms or shelves above
or below it. This ensures its holding, at all times a considerable store of liquor.
Above this diaphragm or shelf we introduce the milk of lime, and we thus secure
its continuous mixture with the body or store of descending liquor retained by the
deep lip. As this store is large enough to contain a considerable quantity of lime
liquor and in working the still we pump continuously into it a slight excess of lime
liquor over the proportion theoretically required, the store tends to minimise the
evil effects of any casual irregularities in the supply of such lime liquor. Such
irregularities would if there were no such store allow portions of the fixed salts of
ammonia at times to pass downwards and out of the still undecomposed. The
mixed liquor passes over the deep lip of the store on to the several diaphragms or
shelves below it where it is exhausted or practically exhausted of its remaining
ammonia by the upward current of steam which it meets on its way to the bottom
of the column or still.
Sixthly, in providing near the closed end of the highest of the upper diaphragms
or shelves a vertical plate or lip of such depth as will retain behind it sufficient
liquor to immerse the mouth of the ammoniacal liquor supply-pipe and thus protect
it from the injurious action of the gases in the still and also ensure the spreading of
the liquor across the whole width of the diaphragm or shelf. The liquor to be
distilled we introduce into the still in the usual way either (a) from a supply tank
placed at a sufficient elevation above it to give a column of liquor of higher
pressure than that of the ammonia gas or vapour within and at the top of the still,
such supply tank being provided with the usual equalizing box, with its ball valve
to give a uniform head of liquor in the pipe which passes out of its bottom to the
still. If the raw liquor is to be passed through a heater on its way from the
equalizing box to the still we in such case find it necessary to increase the height
of the column to overcome the frictional resistance caused by the pipes or other
liquor ways of the heater, or (b), we pump the liquor either direct or through a
heater into the still. We prefer method (a). The spent liquor we discharge from
near the bottom of the still into the usual exit balance pipe or in any other
suitable way.
.
13
In the accompanying drawings,
Fig. 1 is a longitudinal section and Fig. 2. an end elevation partly in section
10

page_text: :
each of similar parts to be distinguished distinguishing numbers are applied to the
reference letters applied to such similar parts.
(a¹) (a³) (a³) (a*) (a³) (a®) (a²) («³) (aº) (a10) (11) (a¹²) are the upper series of
shelves or diaphragms of the still, (b) is the pipe by means of which the aminoniacal
liquor to be distilled is admitted to the still and (c) is the outlet pipe by which the
liquor after being exhausted of its ammonia in the still is allowed to escape
therefrom. (d) (d) are the pipes by which the steam employed to distil off the
ammonia from the ammoniacal liquor is admitted to the still. (e) is the pipe by
means of which the milk of lime employed in the distillation from the ammoniacal
liquor of the aminonia' contained in the fixed salts of ammonia contained in such
ammoniacal liquor is admitted.
()() are the openings by means of which the upward passage of steam and
ammonia and the downward passage of liquid through the still take place.
Figs. 1 and 2 indicate that the column of the still is made oblong instead of
square for the purposes hereinbefore indicated.
(9) (9) are the lips provided upon each shelf or diaphragm in order to secure at
all times a thin stratum of liquor over the whole surface of the shelf or diaphragm.
Fig. 3 shows a longitudinal section upon a larger scale of one of the diaphragms (a)
with its lip (9), and the strong dotted line in Fig. 3 represents the upper surface of
the stratum of liquor retained upon it by the lip (g). Fig. 4 shows a plan of one of
the diaphragms (a). (h) (h) are the manholes or openings provided in each end
of the column every manhole or opening (h) being placed opposite the lip of a
shelf or diaphragm (a) and thus enabling free access to be obtained whenever
requisite to the upper surface of each shelf or diaphragm (a) and also to that of the
shelf or diaphragm (a) below it. The manholes or openings (h) are closed while
the still is in use, by lids, which are secured in position by cross bars.
The shelves or diaphragms (a¹) (a²) (a) (aª) (aª) («º) (u³) (µ³) (a³) (a¹º) (a¹¹) (a¹³)
are employed to distil off the volatile salts of ammonia and the shelves or
diaphragms (a) (a¹¹) (a¹³) (a¹) (a¹³) (a¹³) (a¹³) (a³) (aª¹) (a²²) (a²³) (a²) (a²) (a²6)
are employed to distil off the ammonia of the fixed salts of ammonia contained in
the ammoniacal liquor being treated.
The lip (G) provided upon the shelf or diaphragm (A") is considerably deeper
than the lips (9) provided upon any of the diaphragms or shelves above or below
the diaphragm or shelf (A18). The employment of such a deep lip (G) upon the
diaphragm or shelf (A") ensures that such diaphragm or shelf (A) shall at all
times hold a considerable store of liquor. As is indicated by the position of the
pipe (e) by means of which the milk of lime is introduced, we introduce the milk of
lime above the shelf or diaphragm (A"). We thus ensure the continuous mixture
of the milk of lime with the body or store of descending liquor retained by the
deep lip (G) upon the shelf or diaphragm (A"). As has been herein before
mentioned the mixed liquor passes over the deep lip (G¹³) on to the several
diaphragms or shelves (21). (alb) (219) (917), (ale) (619) (13) (a) diaphragms it is
(a) (a) below the shelf or diaphragın (A") on which shelves or diaphragms it is
exhausted or practically exhausted of its remaining ammonia by the upward
current of steam which it meets on its way to the bottom of the still and the outlet
pipe (c). The diaphragm or shelf (a), is provided near its closed end with a
vertical plate (m) made of such depth that it will retain behind it sufficient liquor
to immerse the mouth of the pipe (6) by which the ammoniacal liquor to be
distilled is introduced into the still. The pipe (b) is thus protected from the
injurious action of the gases in the still and the liquor is spread equally across the
whole width of the shelf or diaphragm (a'). The pipe (6) being thus kept
entirely out of contact with the gases may with complete immunity from injury be
carried if it be considered desirable as we find it to be across the whole width of
the diaphragm or shelf and may in such case bave perforations made along its
whole length to allow of the equable outflow of liquor behind the whole length of
the vertical plate (m). By immersing the pipe (6) and causing it to extend across
the whole width of the diaphragin and providing it with perforations we prevent

page_text: the ammoniacal liquor from splashing, and so prevent any of the liquor being
carried as spray along with the ammoniacal gas or vapour issuing from the still by
means of the pipe (n) and thus avoid the introduction into the product in the
manufacture of which the still is employed of impurities which would be caused by
the occurrence of splashing or spraying in the admission of the ammoniacal liquor
to be operated upon.
Stills constructed according to our invention may be made of iron. Either
wrought iron or steel will do but preferably the latter. We rivet the still at the
angles by angle iron in the way usually adopted by boiler-makers. We find that if
a still is made of such strength as to withstand a pressure not exceeding ten pounds
to the square inch it is strong enough for our purpose. The pipes (d) (b) (e) by
means of which the steam, the ammoniacal liquor, and the milk of lime liquor, are
respectively admitted to the still and the pipe (c) by which the liquor which has
been exhausted of ammonia is allowed to escape from the still are secured in collars
fastened to the walls of the still in suitable positions and leakage of liquid or gas
prevented in any suitable manner as will be obvious to persons conversant with the
construction of stills for the distillation of ammoniacal liquor.
is
As is indicated in Fig. 5 which is a horizontal section through the lower portion of
the still the pipes (d) by which steam is admitted to the still project only a short
distance into the interior of such still. We prefer to arrange them in this way and
to form them with perforations in the portions within the still in order that the
lowest compartment of the still may also be utilized in the distillation of the
. ammoniacal liquor. The perforations in each pipe (d) are formed. in that side of
such pipe which is turned towards the other of such pipes (d). Over the highest of
the upper series of diaphragms we leave a large free space (i) surmounted by a
dome () to prevent priming. Alongside the dome we construct a manhole with its
lid (k) to allow of entrance into the head of the still in case of any derangement of
the liquor supply pipe. We insert a dead weight safety valve (2) on the top of the
still to allow of the escape of steam in case the pressure within the still should from
any cause rise above the safe limit.
As has been herein before mentioned the number of shelves or diaphragms
employed for the distillation from ammoniacal liquor of the volatile salts of
ammonia and the number of shelves or diaphragms employed for the distillation
'from such liquor of the ammonia of the fixed salts of ammonia may each be adapted
to the relative proportions of volatile and fixed salts of ammonia in such liquor for
instance there may be in some cases only one shelf or diaphragm employed for the
distillation from the liquor of the volatile salts while the other and lower shelves or
diaphragms are employed for the distillation from such ammoniacal liquor of the
ammonia of the fixed salts and in other cases there may be only one shelf or
diaphragm employed for the distillation from the liquor of the ammonia of the
fixed salts while the other and higher shelves or diaphragms are employed for the
distillation of the volatile salts.
It is obvious that while in the construction of a still according to our invention
the precise arrangement of the shelves or diaphragms and other parts and the
dimensions and proportions of the parts must be adapted to the particular
ammoniacal liquor in the distillation of which such still is to be employed the
arrangement of the shelves or diaphragms and other parts can not afterwards be
changed except by the still being more or less reconstructed.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. For use in the distillation of ammoniacal liquor a still formed of an obloug
iron column containing a series of oblong horizontal iron shelves or diaphragms
such as are hereinbefore described and shown in the accompanying drawings at (a)
and having formed upon each of such diaphragms or shelves a lip such as (9) and
having the upper series of such shelves or diaphragmns used for distilling off from

page_text: the ammoniacal liquor the volatile salts of ammonia contained therein while the
lower series of such shelves or diaphragms are used for distilling off from the
ammoniacal liquor the ammonia of the fixed salts of ammonia contained therein,
and having upon the highest (a) of the upper set of the said shelves or diaphragms
and near its closed end a vertical plate such as (m) and having the highest of the
lower series (A1) of the said shelves or diaphragms formed with a special lip such
as (G) and having over such last named diaphragm (A") a milk of lime inlet pipe
such as (e) and having openings such as (h) opposite the lips of the several shelves
or diaphragms (a) all for the purposes and substantially in the manner hereinbefore
described and illustrated by the accompanying drawing.
2. For use in the distillation of ammoniacal liquor a still formed of a column
containing horizontal iron shelves or diaphragms made oblong for the purposes and
substantially in the manner herein before described and illustrated by the accom-
panying drawings.
-
3. In a still for use in the distillation of ammoniacal liquor and formed of a
column containing oblong horizontal iron shelves or diaphragms such as are herein-
before described, the employment of one or more of the upper shelves or diaphragmns
for distilling off from the ammoniacal liquor of the volatile salts of ammonia and
the employment of one or more of the lower shelves or diaphragms for distilling off
from the ammoniacal liquor of the ammonia of the fixed salts of ammonia contained
therein.
4. In a still for use in the distillation of ammoniacal liquor and formed of a
column containing horizontal iron shelves or diaphragms, lips such as (9) formed
upon the several shelves or diaphragms at the ends or edges thereof next to the
openings for the steam and liquor for the purpose and substantially in the manner
herein before described and illustrated by the accompanying drawings.
5. For use in the distillation of ammoniacal liquor a still formed of a column
containing horizontal iron shelves or. diaphragms (a) such as are hereinbefore
described, which shelves or diaphragms (a) are inade oblong and provided with
lips (9) for the purposes and substantially in the manner hereinbefore described and
illustrated by the accompanying drawings.
6. In a still for use in the distillation of ammoniacal liquor and formed of a
column of iron shelves or diaphragms, a vertical plate such as (m) formed near the
closed end of the highest (a) of the shelves or diaphragms for the purpose and
substantially in the manner herein before described and illustrated by the accom-
panying drawings.
7. In a still for use in the distillation of ammoniacal liquor and formed of a
column of oblong iron shelves or diaphragms such as are hereinbefore described a
special lip such as (G¹³) and a lime liquor supply pipe such as (e) employed for the
purpose and substantially in the manner herein before described and illustrated by
the accompanying drawings.
Dated this Tenth day of February 1894.
HOWARD CHEETHAM,
Manchester, Agent to the Applicants.