Improvements in Apparatus for use in the Ooncentration of Sulphuric Acid.
Year: 1898

page_text: Date of Application, 28th Dec., 1898
Complete Specification Left, 27th Sept., 1899-Accepted, 4th Nov., 1898
Improvements in Apparatus for use in the Ooncentration of Sulphuric
Acid.
WO, JOHN WILLIAM FISHER, JOHN ALBERT HALL, and FREDERICK MOORE, all
of Erie Street, Outer Wharf, Victoria, British Columbia, in the Dominion of
Canada, Chemists, do hereby declare the nature of this invention to be as
follows:
Our invention has for its object to provide improved means for use in the
concentration of sulphuric acid and consists of an arrangement wherein a cast
iron pipe or cast iron pipes 18, or are, employed in which the sulphuric acid 18
continuously boiled as it passes the ethiough
By "pipe" we mean a vessel or passage of closed cross-section whose length
is considerably greater than its greatest width (say from five times upward).
In carrying out our invention the pipe or pipes is, or are, so mounted horí-
zontally, or approximately horizontally, in brickwork so that the greatest pos-
sible surface is exposed to heat generated by any solid liquid or gaseous fuel
We have found that a cylindrical pipe, or pipes, 10 feet long, one foot in dia-
meter, and from to 1 inch thick, is, or are, suitable, but we do not limit our-
selves to these dimensions or to the use of a cucular pipe, or pipes.
The ends of the pipe, or pipes, are closed by means of separate pieces of
cast iron, or by casting the ends in one with the pipe, or pipes. In each end,
or in the pipe at, or near, each end, we provide a small pipe, or pipes, or open-
ing, or openings, say about 1 inches in diameter, for the inlet and outlet
respectively of the acid
The said small pipe, or opening, or pipes, or openings, 18, 01 are, placed at
such a level as to keep the large pipe, or pipes, about half full of acid
In the first named pipe, or pipes, or in the end pieces thereof, we provide
an outlet, or outlets, for the vapour, the said outlet oi outlets being sav 4 inches
in diameter They are connected to a condensing apparatus, preferably of such
a character as to admit of the specific gravity of the distillate being observed
The outlet pipe, or pipes, or opening, or openings, for the acid is, o1 are,
connected to a cooling apparatus
If the end pieces be bolted on, the first named pipe, or pipes, is, or are, pre-
ferably flanged, and the joint made good by means of asbestos soaked in a
strong solution of silicate of soda and placed between the rough faces of the
castings, and it is preferred to have a choke, o internal projection, cast around
the end, or ends, of the pipe, or pipes, to provide a greater suiface for the
Joint
The inlet pipe, or pipes, may be carried into the first named pipe, or pipes,
for a short distance, (say one-tenth of the length) for the purpose of diminish-
ing_wear
The source of heat is best placed under the inlet end of the first-named pipe,
or pipes, should only one source of heat be used. The said pipe, or pipes,
should be straight and in case the vapour is only withdiawn at one place it
is best withdrawn at the inlet end.

page_text: The bolt holes, or slots, in the pipe, or pipes, for the end pieces, should be
airanged so as to admit of the pipe being turned through quarter tuins in
order to regulate the wear
Irregular surfaces, coriugations, pittings, and the like, and internal divi-
sions, are preferably avoided as they are liable to cause deposits and consequent
cracking.
า
One pipe, or two, or more, pipes, may be mounted in the brickwork of-the
furnace, and when two, or more, are used they may be either separate, or con-
nected in such a manner as to cause the acid to flow through them successively.
The inlet and outlot pipes, or openings, are preferably in the end pieces
instead of in the body of the pipe, for ease of mounting and replacement in the
brickwork
The acid after coming out of the pipe, or pipes, may be run through a cast
iron settling box of any suitable size and shape such as for example a cylinder
standing on end. It should be provided with a mud hole for 'withdrawing the
sediment The settlement should take place before the acid 18 cooled as the
sediment settles more quickly from hot acid than it does fiom cold acid
The brickwork over the pipe, 01 pipes, is conveniently in the form of an
arch made up of sections in an iron fiame-work, or of fire-clay slabs, they
being in any case so arranged as to be easily removed, say by over-head gear,
to facilitate the removal of a damaged pipe
The heated products of combustion from the furnace, or the like, after heat-
ing the pipe, or pipes, may be conducted under ordinary lead pans in which
the distillate, o feed acid, may be concentiated
When the apparatus is in operation the pipe, or pipes, 18, 01 are, heated
whilst a stream of the sulphuric acid to be concentrated is iun through the said
pipe, or pipes If the acid be below 170 specific gravity it should be brought
up to this strength in lead pans The temperature of heating, or the rate of
flow of the acid, or both, 18, or are, so regulated that the distillate is at, or
about, a specific gravity previously determined as being requisite for the strength
of acid desired For example in an apparatus of the sizes mentioned a distil-
late of a specific gravity of about 1'45 corresponds to a strength of concen-
trated acid of 95-96 per cent using a feed acid of a specific gravity of 173
Dated this 28th day of December 1898
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, WC, Agents
Improvements in Apparatus for use in the Concentration of Sulphurio
Acid.
We, JOHN WILLIAM FISHER, JOHN ALBERT HALL, and FREDERICK MOORE, all
of Erie Street, Outer Whaif, Victoria, British Columbia, in the Dominion of
Canada, Chemists, do hereby declare the nature of this invention and in what
manner the same is to be performed to be particularly described and ascer-
tained in and by the following statement:
-
->
Our invention has for its object to provide improved means for use in the
concentration of sulphuric acid and consists of an arrangement as hereinafter
described and illustrated wherein a pipe, or pipes, of cast iron, or malleable
cast iron, is, or are, employed in which the sulphuric acid 18 continuously boiled
as it passes therethrough. By "pipe" we mean a vessel, or passage, of closed
cross-section whose length 18 considerably greater than its greatest width; say
وو

page_text: from five times greater or upwards The said pipe, or pipes, 18, or are, mounted
horizontally, or approximately horizontally, in brickwork, or other suitable, set-
ting, so that the greatest possible surface 18 exposed to heat generated by any
solid, liquid, or gaseous, fuel. We have found that a cylindrical pipe, or pipes,
10 feet long, one foot in diameter, and from 1 to 1 inch thick 18, or are, suit-
able, but we do not limit ourselves to these dimensions, or to the use of a oylin-
drical pipe, or pipes. The ends of the pipe, or pipes, are closed, by means
of separate pieces of cast, or malleable cast, iron, or by casting the ends in one
with the pipe, or pipes
In each end, or in the pipe at, or near, each end, we
provide a small pipe, or pipes, or opening, or openings, say about 1 inches
in diameter, for the inlet and outlet respectively of the acid; the said small
pipe, or opening, or pipes, or openings, being placed at such a level as to keep
the large pipe, or pipes, about half full of acid.
In the first named pipe, or pipes, or in the end pieces thereof, we provide an
outlet, or outlets, for the vapour, the said outlet, or outlets, being, say, 4 inches
in diameter, and being connected to a condensing apparatus preferably of such
a character as to admit of the specific gravity of the distillate being observed.
The outlet pipe, or pipes, or opening, or openings, for the acid 18, or are,
connected to a cooling apparatus
If the end pieces be bolted on, the first named pipe, or pipes, is, or ale, pre-
ferably flanged and the Joint made good by means of asbestos, soaked in a
stiong solution of silicate of soda or coated with graphite and placed between
the rough faces of the castings, and it is pieferied to have a choke, or internal
projection, cast around the end, or ends, of the pipe, or pipes, to provide a
greater surface for the joint
The inlet pipe, or pipes, may be carried into the first-named pipe, or pipes,
for a short distance (say one-tenth of the length) for the purpose of diminish-
ing wear
The source of heat is best placed under the inlet end of the first-named pipe,
or pipes, should only one source of heat be used The said pipe, or pipes,
should be straight and, in case the vapour 18 only withdrawn at one place, it
18 best withdrawn at the inlet end.
When the vapour outlet, or outlets, 18, or are, in the end piece, or end pieces,
the bolt holes, o1 slots, in the pipe, or pipes, for the end pieces, should be
arianged so as to admit of the pipe or pipes being turned partly round, say a
quarter turn, and refixed, for iegulating the wear
.
Irregular surfaces, corrugations, pittings, and the like, and internal divi-
sions, should be avoided as they are liable to cause deposits and conscquent
cracking.
One pipe, or two, or more, pipes, may be mounted in the same brickwork,
or other setting, and, when two, or more, are used, they may be either separate,
o be connected in such a manner as to cause the acid to flow through them
successively.
The inlet and outlet pipes, or openings, are preferably in the end pieces
instead of in the body of the pipe, for ease of mounting and replacement in
the brickwork.
The acid after coming out of the pipe, or pipes, may be run through a cast
11 on settling box of any suitable size and shape such as for example a cylinder
standing on end It should be provided with a mud-hole for withdrawing the
sediment The settlement should take place before the acid is cooled as the
sediment settles more quickly from hot acid than it does from cold acid
The brickwork, or the like, over the pipe, or pipes, is conveniently made in
the form of an arch made up of sections in an iron framework, or of fire-clay
slabs, they being so arranged as to be easily removed, say by over-head gear,
to facilitate the removal of a damaged pipe
The heated products of combustion from the furnace, or furnaces, after heat-

page_text: ing the pipe, or pipes, may be conducted under lead pans in which the distil-
late, o feed acid, may be concentrated
When the apparatus is in operation the pipe, or pipes, 18, or are, heated
whilst a stream of the sulphuric acid to be concentrated is run through the
said pipe, or pipes If the acid be below 170 specific gravity 18 should be
brought up to this strength in lead pans The temperature of heating, or the
rate of flow of the acid, or both, is, oi are, so regulated that the distillate is at,
or about, a specific gravity previously determined as being requisite for the
strength of acid desired for example in an apparatus of the sizes mentioned
a distillate of a specific gravity of about 145 corresponds to a strength of con-
centrated acid of from 95 to 97 per cent. using a feed acid of a specific gravity
of 1.73
We will describe with reference to the accompanying drawings an arrange-
ment according to our invention Figure 1 18 a plan; partly in section, and
Figure 2 is an elevation, partly in section, of the apparatus Figure 3 18 an
elevation of one of the end pieces and Figure 4 18 a section shewing one end of
one of the aforesaid pipes with the end piece in place.
The apparatus 18 shewn as having two of the aforesaid pipes heated by one
furnace and cach with its depositing vessel condensers and cooler, but it is to
be understood that one, two, or more, of each can be used as may be convenient.
The pipes A are mounted horizontally in the brickwork setting B within
which is the furnace C The ends of the pipes A are closed by the ends a,
each of the end pieces at the inlet end of the pipes A having cast with it a
piece for the attachment of an inlet pipe for the acid to be concentrated (the
said inlet preferably projecting into the pipe as shewn in Figure 4) and each of
the end pieces at the other end of the pipes A has cast with it a piece for the
attachment of an outlet pipe for the concentrated acid to the settling boxes E.
These inlets and outlets for the acid are at auch a level as to keep the pipes A
about half full of acid The aforesaid internal projections around the ends of
the pipes A to provide large surfaces for the joints are marked at. The outlet
pipes dip into the acid in the settling boxes E and sediment can be removed
by the mud holes as ate the acid leaving the settling box by the overflow
pipes which dip into the acid in the cooling boxes which have each an
upward overflow and each is Burounded by a water jacket through which
cold water, or other cooling agent, is passed The vapours and gases from the
pipes A are conducted by the outlet pipes D to the condensers D from which
the products of condensation are led off by the outlets d leading, by pipes d³,
into a hydrometer G The acid to be concentrated is fed by the pipes and
taps H into troughs from which it passes by the troughs to the inlets to
the pipes A
In Figures 1 and 2 we have shewn the pipes D³ as leading from the upper
parts of the pipes A themselves, but to enable the said pipes to be turned as
aforesaid we prefer to cast the end pieces with an elbow (for the connection
of the pipes D) as shown in Figures 3 and 4-the outlet pipe to the condenser
being then made with a bend ascending from the retort and descending to
the condenser and the latter part may be surrounded by a water jacket
We prefer to make the connection of the said end pieces to the pipes A and
of the outlet and inlet pipes to the parts for the attachment thereof by means
of bolts and nuts, the bolts being passed through slots in the flanges as
shewn in Figures 3 and 4
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is
—
1 An apparatus for concentrating sulphuric acid the said apparatus being
constructed or arranged substantially as herein before described and illustrated in
F1 and 2 of the accompanying drawings

page_text: 2. In apparatus for concentrating sulphuric acid a cast, or malleable cast,
iron pipe, or pipes, provided with end pieces having inlets and outlets cast
thereon as herein before described and illustrated in Figures 3 and 4 of the
accompanying drawings.
3. In apparatus for concentrating sulphuric acid a cast, or malleable cast,
iron pipe, or pipes, with a choke, or inward projection, at the ends and with
end pieces with inlet and outlet connections and means for attachment so
arranged as to allow of the turning of the pipe or pipes as hereinbefore explained
Dated this 27th day of September 1899
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.