IMPROVEMENTS IN TREATING HYDROCHLORIC ACID, IN APPARATUS OR APPLIANCES EMPLOYED THEREIN AND IN THE MANUFACTURE OF THE SAID
Year: 1882

page_text: LETTERS PATENT to John Hargreaves of Widnes in the County of Lancaster
Chemist and Thomas Robinson of the same place Iron founder for an
Invention of IMPROVEMENTS IN TREATING HYDROCHLORIC ACID, IN APPARATUS
OR APPLIANCES EMPLOYED THEREIN AND IN THE MANUFACTURE OF THE SAID
PROVISIONAL SPECIFICATION left by the said John Hargreaves and Thomas
Robinson at the Office of the Commissioners of Patents on the 6th December
1882.
JOHN HARGREAVES of Widnes in the County of Lancaster, Chemist, and THOMAS
ROBINSON of the same place Iron-founder, "IMPROVEMENTS IN TREATING HYDRO-
CHLORIC ACID, IN APPARATUS OR APPLIANCES EMPLOYED THEREIN, AND IN THE
MANUFACTURE OF THE SAID APPARATUS."
The invention consists in improvements in treating hydrochloric acid, in
methods means and appliances for cooling, condensing refrigerating, purifying,
moving conveying, storing heating and evaporating hydrochloric acid, in apparatus
employed therein, and in the manufacture of such apparatus.
Considerable difficulty has been found heretofore in cooling condensing and
handling hydrochloric acid especially hydrochloric acid evolved during the
manufacture of sulphate of soda, on account of the high temperature of the gas as
it issues from the apparatus in which the chloride of sodium is being decomposed
and also on account of the corrosive nature of the acid. The use of pipes or
conduits made of iron, earthenware or of glass as at present employed for cooling
the gaseous hydrochloric acid on its passage from the decomposing apparatus to the
scrubbers present many practical difficulties and inconveniences.
During the manufacture of sulphate of soda the hydrochloric acid gas evolved
always contains more or less acqueous vapour. When iron pipes are used they are
rapidly corroded wherever the temperature of the hydrochloric acid gas becomes so
low as to condense upon its surface. When earthenware pipes are used for the
[Price 6d1

page_text: purpose of cooling and condensing they are necessarily made of considerable
thickness to prevent breakage: their power of conducting heat is thereby greatly
diminished and large radiating surface becomes necessary.
Earthenware pipes too being more or less porous allow the gaseous and liquid
acid to permeate the body of the pipe, and cause considerable annoyance by
disseminating of the hydrochloric acid into the surrounding atmosphere. In
addition to these inconveniences earthenware pipes are frequently broken by the
heat of the gases and sudden changes of temperature.
Glass pipes as at present used are very fragile, liable to be broken by vibration
and sudden changes of temperature.
The heating and moving of hydrochloric acid (without dilution) has up to the
present time, except by means and methods recently invented by us been found
almost impracticable. It is to overcome the difficulties and inconvenience hitherto
attendant upon these operations and to render practical and expeditious the
treatment and manufacture of hydrochloric acid which forms part of the object of
our present invention.
We have found that pure or nearly pure metallic antimony or particular alloys
thereof to be the only available metal capable of withstanding the corrosive action
of hydrochloric acid; We have also found that when antimony is alloyed with
other metals electro-positive to any considerable degree to that of antimony, the
alloy thus formed is acted upon and destroyed by the action of liquid hydrochloric
acid. The only practically available metal with which to alloy antimony for the
purposes herein mentioned is bismuth. Pure unalloyed antimony is very brittle
and has feeble tenacity. We find however under certain conditions hereinafter
mentioned that pure antimony can be made available under our present invention.
To give extra tenacity to apparatus made of antimony we avoid as far as possible
the formation of large crystals in the body of the antimony casting; We find that
this is best accomplished by allowing the metal to solidify as soon as practicable,
after it has been poured into the mould. We support the pipes conduits or vessels
of antimony by means of other metals having a higher tenacity than that of
antimony, such as iron and copper.
Apparatus for the treatment of hydrochloric acid is arranged in the following
manner. A vessel preferably made of stone of any usual or desired construction,
the sides of which are perforated receives the ends of pipes, made of or coated with
antimony. These pipes pass into the vessel and are caulked and made tight from
the interior. Within the vessel and surrounding the pipes water is maintained at
a lower temperature than that of the hydrochloric acid gas passing through the
antimony pipes. The water in the vessel is maintained at a suitable temperature
by passing a stream of cold water into the bottom of the vessel and withdrawing
the warm water from the upper part.
Under a second method of treating hydrochloric acid a vessel made of antimony
or other suitable material has through perforations on opposite sides. Pipes made
of or coated with antimony fit into these perforations, and are caulked on the
outside. The hydrochloric acid to be cooled circulates on the exterior of the pipes
whilst cold air is caused to pass through them.
A third modification has a number of pipes made of or lined with. antimony (or
it may be glass) and closed at one end suspended from the cover of a rectangular
or other vessel through which vessel the gaseous hydrochloric acid is caused to
pass. The said pipes are maintained at a low temperature by means of, water
circulating therein in the manners described and thereby serve to convey the heat
from the hydrochloric acid. The packing of the said pipes effected by washers
of india-rubber or other suitable material.
In one arrangement of cooler or cooling pipes for hydrochloric acid we make the
pipes of antimony of a tapering form and cause them to fit at the ends or junction
one inside the other and we strengthen the junction by fitting a ring of iron
or other metal of high tenacity on the end of larger diameter. To prevent

page_text: bydrochloric acid by leaking coming in contact with the iron or other ring we
construct the pipes with antimony extending beyond the iron or other ring. The
joints of the pipes may be made tight with a mixture of china clay and tar or other
suitable material, or the sockets may be made to fit tight so as to dispense with
caulking.
$
A second modification of cooler or cooling pipes made of antimony has a spigot
and faucet connection the faucet being so strengthened as to avoid breakage either
by an iron or other ring or by extension of metal laterally..
1 .
A third modification of cooler or cooling pipes consists in making such pipes of
antimony strengthened by metal by preference of iron. The antimony overlaps at
the ends so that any acid leaking past shall not attack the iron. The antimony is
thickened at the overlapping part. This construction provides a strong durable
pipe.
A fourth modification of cooler or cooling pipe is made by casting antimony
around a perforated body of iron or other suitable metal. This provides a cheap
pipe when wire gauze is used as the body.
Pipes suitable for conveying hydrochloric acid particularly liquid hydrochloric
acid are made of antimony and other metal with true and slightly taper junctions,
and such junctions are kept together by clamped or bolted flanges.
For moving hydrochloric acid under our invention we construct pumps and other
like apparatus of antimony and iron or other metal expanding at about the same
rate as antimony. The antimony alone must come into contact with the hydro-
chloric acid hence it is better to embed the iron or other metal wholly in antimony.
although that is not strictly necessary. In casting such pumps or apparatus the
fluid antimony must not exceed 1600° fahrenheit. This temperature applies not
only to compound pumps and apparatus but also to these appliances when wholly
made of antimony.
For heating or evaporating hydrochloric acid we make a compound vessel, the
exterior one being of wrought iron with steam jacket and the interior one of
antimony. The antimony has the requisite ways extending past the outer iron
case. The antimony also extends over the iron around the mouth of the vessel. To
convey away the evaporated acid a close fitting hood and pipe are used. Evaporation
will be hastened by agitating the acid.
A modification of apparatus for heating or evaporating hydrochloric acid consists
of a containing vessel and of antimony pipes without joints in their parts which
are immersed in the acid. These pipes are by preference of bent form the points of
greatest depression being near to the bottom.
To obtain hydrochloric acid of high specific gravity, we pass gaseous hydrochloric
acid containing acqueous vapour through any of the cooling appliances previously
described and afterwards conduct the condensed hydrochloric acid together with
the excess of gaseous hydrochloric acid through refrigerating apparatus now to be
described. This apparatus consists of a closed vessel made of metallic antimony
surrounded by another vessel or casing a refrigerating medium being passed
between the two vessels. The excess of gaseous hydrochloric acid is conveyed
away to be condensed in any convenient manner
We will now proceed to describe the method and apparatus employed in the
treatment of hydrochloric acid for obtaining liquid bydrochloric acid comparatively
free from impurities. A scrubber constructed of stone, brick or other suitable
material packed with coke in the ordinary manner is placed midway betwixt the
furnace, pot or cylinder from which the hydrochloric acid is evolved The interior
of the said purifier is maintained at such a temperature as to condense only a small
portion of the hydrochloric acid. This temperature will vary according to the
amount of acqueous vapour contained in the hydrochloric acid. The perchloride of
iron and sulphuric acid which condense at a lower temperature than acqueous
vapour or hydrochloric acid will be retained more or less within the purifier whilst
the greater part of the gaseous hydrochloric acid will pass out to the cooling or

page_text: condensing apparatus herein before described. The gaseous hydrochloric acid is
conveyed to a scrubber of the usual form and materials. If the gas contains sufficient
acqueous vapour before entering the scrubber and is sufficiently cooled a small
quantity of the gas will be condensed together with a considerable portion of the
chloride of iron, sulphuric acid and arsenic with which the gas is always more or
less contaminated. If on the other hand the gas does not contain sufficient moisture
it is added in the scrubber when the same effects are produced. The gaseous
hydrochloric acid which has been purified in the scrubber is passed to be cooled
condensed or refrigerated in any of the appliances hereinbefore described. When
hydrochloric acid is used in antimony appliances under our invention it is highly
beneficial to subject such acid to the purifying treatment mentioned in this part of
our improvements.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John Hargreaves and Thomas Robinson in the Great Seal Patent
Office on the 6th June 1883.
JOHN HARGREAVES of Widnes in the county of Lancaster, Chemist, and THOMAS
ROBINSON of the same place, Iron Founder. "IMPROVEMENTS IN TREATING
HYDROCHLORIC ACID, IN APPARATUS OR APPLIANCES EMPLOYED THEREIN, AND IN
THE MANUFACTURE OF THE SAID APPARATUS"
The invention consists in improvements in treating hydrochloric acid, in methods
means and appliances for cooling, condensing refrigerating purifying, moving
conveying storing heating and evaporating hydrochloric acid, in apparatus employed
therein, and in the manufacture of such apparatus.
Considerable difficulty has been found heretofore in cooling, condensing and
handling hydrochloric acid especially bydrochloric acid evolved during the manu-
facture of sulphate of soda, on account of the high temperature of the gas as it
issues from the apparatus in which the chloride of sodium is being decomposed and
also on account of the corrosive nature of the acid. The use of pipes or conduits
made of iron, earthenware, or of glass as at present employed for cooling the gaseous
hydrochloric acid on its passage from the decomposing apparatus to the scrubbers
present many practical difficulties and inconveniences.
During the manufacture of sulphate of soda the hydrochloric acid gas evolved
always contains more or less aqueous vapour. When iron pipes are used they are
rapidly corroded wherever the temperature of the hydrochloric acid gas becomes so
low as to condense upon its surface. When earthenware pipes are used for the
purpose of cooling and condensing they are necessarily inade of considerable
thickness to prevent breakage; their power of conducting heat is thereby greatly
diminished and large radiating surface becomes necessary.
Earthenware pipes too being more or less porous allow the gaseous and liquid
acid to permeate the body of the pipe, and cause considerable annoyance by
disseminating of the hydrochloric acid into the surrounding atmosphere. In
addition to these inconveniences earthen ware pipes are frequently broken by the
heat of the gases and sudden changes of temperature.
Glass pipes as at present used are very fragile, liable to be broken by vibration
and sudden changes of temperature.
The heating and moving of hydrochloric acid (without dilution) has up to the
present time, except by means and methods recently invented by us, been found
almost impracticable. It is to overcome the difficulties and inconvenience hitherto
attendant upon these operations and to render practical and expeditious the
treatment and manufacture of hydrochloric acid which forms part of the object of
our present invention.
We have found that pure or nearly pure metallic antimony, or particular alloys
thereof, to be the only available metal capable of withstanding the corrosive action
of hydrochloric acid. We have also found that when antimony is alloyed with
other metals electro positive to any considerable degree to that of antimony, the
alloy thus formed is acted upon and destroyed by the action of liquid hydrochloric
acid. The only practically available metal with which to alloy antimony for the
purposes herein mentioned is bismuth. Pure unalloyed antimony is very brittle and
has feeble tenacity. We find however under certain conditions hereinafter
mentioned that pure antimony can be made available under our present invention.
To give extra tenacity to apparatus made of antimony we avoid as far as

page_text: 2
possible, the formation of large crystals in the body of the antimony casting; We
find that this is best accomplished by allowing the metal to solidify as soon as
practicable after it has been poured into the mould. We support the pipes,
conduits or vessels of antimony by means of other metals having a higher tenacity
than that of antimony, such as iron and copper.
Apparatus for the treatment of hydrochloric acid is arranged in the following
manner. A vessel, preferably made of stone, of any usual or desired construction,
the sides of which are perforated, receives the ends of pipes made of or coated with
antimony. These pipes pass into the vessel and are caulked and made tight from
the interior. Within the vessel and surrounding the pipes water is maintained at
a lower temperature than that of the hydrochloric acid gas passing through the
antimony pipes. The water in the vessel is maintained at a suitable temperature
by passing a stream of cold water into the bottom of the vessel and withdrawing
the warm water from the upper part.
T
Under, a second method of treating hydrochloric acid a vessel made of antimony
or other suitable material has through perforations on opposite sides. Pipes made
of or coated with antimony fit into theso perforations, and are caulked on the
outside. The hydrochloric acid to be cooled circulates on the exterior of the pipes
whilst cold air is caused to pass through them.
it
A third modification has a number of pipes made of or lined with antimony. (or
may be glass) and closed at one end suspended from the cover of a rectangular
or other vessel through which vessel the gaseous hydrochloric acid is caused to
pass. The said pipes are maintained at a low temperature by means of water
circulating therein in the manner described and thereby serve to convey the heat
from the hydrochloric acid. The packing of the said pipes is effected by washers
of india rubber or other suitable material..
Fig 1 is a vertical section, and fig 2 a plan of a condenser constructed in the
manner last above described. a are pipes made of antimony closed at the lower
ends and suspended by lips from the cover b of the rectangular vessel c. d'india
rubber washer. fg hydrochloric acid gas inlet and outlet. hi inlet and outlet
for water.
In one arrangement of cooler or cooling pipes for hydrochloric acid we make the
pipes of antimony of a tapering form and cause them to fit at the ends or junction
one inside the other and we strengthen the junction by fitting a ring of iron or
other metal of high tenacity on the end of larger diameter. To prevent hydro-
chloric acid by leakage coming in contact with the iron or other ring, we construct
the pipes with antimony extending beyond the iron or other ring. The joints of
the pipes may be made tight with a mixture of china clay and tar or other
suitable material, or the sockets may be made to fit tight so as to dispense with
caulking.
A second modification of cooler or cooling pipes made of antimony has a spigot
and faucet connection the faucet being so strengthened as to avoid breakage cither
by an iron or other ring or by extension of metal laterally.
A third modification of cooler or cooling pipes consists in making such pipes of
antimony strengthened by metal, by preference of iron. The antimony overlaps at
the ends so that any acid leaking past shall not attack the iron. The antimony
is thickened at the overlapping part. This construction provides a strong durable
pipe.
Fig 3 is a sectional view of a pipe constructed in accordance with the modification
last above described. j is an antimony pipe cast inside the iron strengthening
pipe. The antimony pipe j overlaps the iron pipe k at the ends Z.
A fourth modification of cooler or cooling pipe is made by casting antimony
around a perforated body of iron or other suitable metal. This provides a cheap-
pipe when wire gauze is used as the body.
Fig 4 is illustrative of a pipe constructed in the manner last above set forth.,
m wire gauze body., n, antimony.

page_text: Pipes suitable for conveying hydrochloric acid particularly liquid hydrochloric
acid are made of antimony or antimony and other metal with true and slightly
taper junctions, and such junctions are kept together by clamped or bolted flanges.
For moving hydrochloric acid under our invention We construct pumps and
other like apparatus of antimony and iron or other metal expanding at about the
same rate as antimony. The antimony alone must come into contact with the
hydrochloric acid lience it is better to embed the iron or other metal wholly in
antimony although that is not strictly necessary. In casting such pumps or
apparatus the fluid antimony must not exceed 1600° fahrenheit. This temperature
applies not only to compound pumps and apparatus but also to these appliances
when wholly made of antimony.
Fig 5 is a vertical section of a pump under our invention. o antimony; p iron,
strengthening pieces; it will be noticed that the parts bearing strain are made
much heavier than is necessary with the metals usually employed and that the
iron strengthening pieces are entirely surrounded by antimony.
For heating or evaporating hydrochloric acid we make a compound vessel, the
exterior one being of wrought or cast iron with steam jacket and the interior one
of antimony: The antimony has the requisite ways extending past the outer iron
case. The antimony also extends over the iron around the mouth of the vessel.
To convey away the evaporated. acid a close fitting hood and pipe are used.
Evaporation will be hastened by agitating the acid.
Fig 6 is a vertical section of a compound vessel for heating or evaporating.
hydrochloric acid constructed substantially as above set forth. q is an exterior
vessel of wrought or cast iron with steam jacket between it and the interior
vessels of antimony, t steam inlet, u condensed water outlet. The interior vessel
is carried by the flanges v, w outlet ways, antimony hood or cover and pipe
surrounded and strengthened by iron y. z caulking space.
A modification of apparatus for heating or evaporating hydrochloric acid consists
of a containing vessel and of antimony pipes without joints in their parts which
are immersed in the acid. These pipes are by preference of bent form the points
of greatest depression being near to the bottom.
To obtain hydrochloric acid of high specific gravity, we pass gaseous hydro-
chloric acid containing aqueous vapour through any of the cooling appliances
previously described and afterwards conduct the condensed hydrochloric acid
together with the excess of gaseous hydrochloric acid through refrigerating
apparatus now to be described. This apparatus consists of a vessel provided with
an inlet and outlet pipe and a draw off cock made of metallic antimony surrounded
by another vessel or casing, a refrigerating medium being passed between the
two vessels. The excess of gaseous hydrochloric acid is conveyed away to be
condensed in any convenient manner.
We will now proceed to describe the method and apparatus employed in the
treatment of hydrochloric acid for obtaining liquid hydrochloric acid comparatively
free from impurities. A scrubber constructed of stone, brick or other suitable
material packed with coke in the ordinary manner is placed midway betwixt the
furnace, pot or cylinder from which the hydrochloric acid is evolved and the
condenser in which the bulk of the hydrochloric acid is to be condensed. The
interior of the said purifying scrubber is maintained at such a temperature as to
condense only a small portion of the hydrochloric acid. This temperature will
vary according to the amount of aqueous vapour contained in the hydrochloric
acid. The per-chloride of iron, sulphuric acid and other impurities which condense
at a lower temperature than aqueous vapour or hydrochloric acid will be retained
more or less within the purifier whilst the greater part of the gaseous hydrochloric
acid will pass out to the cooling or condensing apparatus hereinbefore described.
The gaseous hydrochloric acid is conveyed to a scrubber of the usual form and
materials. If the gas contains sufficient aqueous vapour before entering the .
scrubber and is sufficiently cooled a small quantity of the gas will be condensed
together with a considerable portion of the chloride of iron, sulphuric acid and

page_text: arsenic with which the gas is always more or less contaminated. If on the other
hand the gas does not contain sufficient moisture it is added in the scrubber when
the same effects are produced. The gaseous hydrochloric acid which has been
purified in the scrubber is passed to be cooled condensed or refrigerated in any of
the appliances hereinbefore described. When hydrochloric acid is used in antimony
appliances under our invention it is highly beneficial to subject such acid to the
purifying treatment mentioned in this part of our improvements.
Having now described and particularized the said invention in such manner
that others will be enabled to carry our improvements into effect we would have it
understood that in some cases apparatus with glass as mentioned is to be preferred
to antimony as for instance when the hydrochloric acid gas is contaminated
with sulphuric acid and perchloride of iron or either of them. What we
claim is
The treatment of hydrochloric acid substantially as herein described.
The apparatus or appliances herein described for use in the treatment of hydro-
chloric acid substantially as set forth.
Manufacturing the apparatus herein described for the purposes set forth.
In witness whereof I the said John Hargreaves have hereunto set my
hand and seal this fourth day of June in the year of our Lord one
thousand eight hundred and eighty three.