Manufacture of Sulphuric Acid.
Year: 1899

page_text: Manufacture of Sulphuric Acid.
A communication from the PRATT PROCESS COMPANY, a Corporation organized
and existing under the laws of the State of Georgia, one of the United
States of America, and doing business at Atlanta, in the County of Fulton,
and State of Georgia, and elsewhere.
I, ALFRED JULIUS BOULT, of 111, Hatton Garden, Holborn Circus, in the
County of Middlesex, Chartered Patent Agent, do hereby declare the nature of
this invention and in what manner the same is to be performed, to be -particu-
larly described and ascertained in and by the following statement: ---
The object is to cheapen the production of sulphuric acid, and to increase the
output of a given acid-producing space.
In the drawings:
Figures 1 and 2, are, respectively, views in side elevation and in plan, dis-
playing one form of embodiment of my invention.
Figure 3 is a view similar to Fig. 1, displaying another embodiment thereof.
Figures 4, 5 and 6, are views in side elevation, of slightly modified forms of
apparatus.
Figure 7 is a like view, of still another modified form of apparatus.
its rear,
A salient feature of this invention, and one common to all of the different
apparatuses shown in this application, is the employment of means for effecting.
rapid return of the partially-spent gases from any part of the apparatus towards
back toward the front thereof, and the mechanical projection and
thorough admixture of such returned gases with the freshly-entering gases or
acid-making materials from the generators, either before or after entry of these
latter gases into the apparatus, whereby intimate mixture of such gases will be
effected, resulting in rapid and continuous precipitation of sulphuric acid.
The mechanical appliances for effecting the results named, in this instance a
fan or blower, also operates to cause a direct pull or suction on the furnace and
Glover tower, or on either, and a positive and advantageous pressure on the re-
mainder of the system, this pressure being more or less under the control of the
operator by closing or opening suitable dampers located at proper points in the
system. The advantages named can be secured by withdrawing the gases from
any part of the system, top, sides, bottom, or ends of either chambers, flues, etc.,
and reintroducing them into the acid-producing space or chamber, under a strong
blast from the exhauster or fan, either passing them first through a converter
or converters, or using a flue or flues alone without connection with converters.
Referring to the first embodiment of the invention, illustrated in Fiøs

page_text: and 2, A designates the furnaces; B the nitre oven, arranged, by preference, in
rear of and connected with the furnace; C the Glover tower; D the Gay-
Lussac tower; E the acid chamber, which may be a single chamber, as shown,
or a number of communicating chambers; the converters; G the cooling
chamber; H the compressors; I and J the scrubbers; and K a flue connecting
the Glover tower and the acid chamber. These parts may be of any of the well-
known or preferred constructions in ordinary use, and need no further description.
Similar parts of the apparatus occurring in the various modified forms hereinafter
described, will bear like letters of reference, and will not, therefore, be again
specifically described.
Opening into the flue K, and having its discharge-mouth pointing in the
direction of the draft from the furnace, is a flue or pipe L which connects with
the casing M of a blower or fan located contiguous to the chamber E, said fan
being driven by any suitable power, as by an ordinary engine. In this instance
a single fan is shown; but two or more fans may, in some instances be employed,
or any other mechanical appliance, such as a steam-injector, capable of causing
an artificial draft in the furnace, consequent pressure on the chamber system,
and a progressive mixing or circulation within the acid chamber.
Connecting with the fan-casing M is a flue or pipe N which connects with
branch-pipes leading from the converters F at or near the tops thereof, and
connecting with the bottom portion of the converters are pipes or flues f2, leading
from the sides of the acid chamber, for conveying the acid-making materials
to the converters, which latter may occupy either a vertical or horizontal position,
as may be preferred. These converters are furnished with an acid-proof packing,
as are also the scrubbers I and J, the packing permitting spaces for draft, and
surfaces for precipitation, conversion, and decomposition. In lieu of the con-
verters, and scrubbers, any part of the flues N and f2 may be furnished with an
acid-proof packing, and be made to perform the functions of the said parts.
The scrubbers I and J are located, in this instance, respectively, between the
acid chamber E and the cooling chamber G, and at the rear of the cooling
chamber, and are connected with these parts by pipes or flues i, and j, suitable
dampers, at the rear portion of the flue O connecting the scrubber J with the
Gay-Lussac tower, and o2 in this flue adjacent to the tower, being provided for
the purpose of controlling the draft.
In this instance, there is shown only one fan and a single flue leading thereto;
but it is to be understood that two fans may be employed, the flues therefrom
to connect with a single flue L leading into the flue K from the Glover tower;
or, each fan may be provided with a flue connecting with the flue K.
The necessary water for hydration may be added to the system by a steam-
jet P, entering the chambers, or flues, or converters; or by showering water or
weak acid through the converters in the ordinary way, as from a tank f supplied
with water or acid in any convenient manner, or through one of the scrubbers, or
by all three procedures.
The operation of this embodiment of the invention is as follows:
The plant being in operation-that is to say, the generation of sulphurous
acid having begun, my process commences. By the mechanical means described,
the gases, etc., are mixed thoroughly and continuously throughout the whole
extent of the acid-producing portion of the apparatus, or any part thereof, from
and including the furnace or sulphurous acid generator, up to and as far as the
Gay-Lussac tower. At the same time, from near the rear of the acid-producing
portion of the apparatus, most of the suspended gases, vapors, and misty particles
not precipitated before reaching that point, are drawn through the flues into
the bottom of the converters and pass upward through the spaces between the
packing thereof. In this passage, by projection against the packing, most of the
sulphuric acid entering in a state of suspension from the acid-producing portion
of the apparatus is precipitated, also most of any nitro-sulphuric acid entering

page_text: State of suspension from the acid-producing portion of the apparatus, upon
meeting water or dilute sulphuric acid, showered through the packing at the
top of the converters, splits up into sulphuric acid and nitrous anhydride. The
sulphuric acid which is immediately precipitated, joins the other precipitated
5 sulphuric acid, and passes through a suitable pipe to the receiving-pan or tanks.
Also, most of any sulphurous acid which has escaped conversion in the acid-pro-
ducing of the apparatus combines, with the nitrogen acids and water, forming
nitro-sulphuric acid, which immediately splits up into sulphuric acid and nitrous-
anhydride, the oxygen excess, the inert nitrogen present, and any of the before-
mentioned, or other compounds, which have escaped retention in the converters,
are returned through the flues f and N, to the fan-casing, thence through the
flue L to the flue K leading from the Glover tower, and thence, in direct contact
with the freshly-entering acid-making materials from the generators, back to
the acid chamber. From the rear of the main chamber, or the last of the front
chambers, the gases not returned to the front of the chamber pass through a
flue into the scrubber I, thence into a small or cooling-chamber, wherein pre-
cipitation is effected of any small quantity of sulphuric acid which may be
mechanically carried over into it, and thence by the flue to the scrubber J
where most of any remaining sulphuric acid is precipitated, caught and returned
along with the acid from the scrubber I and the cooling-chamber G, to the
chamber-pan. By this procedure, there is a saving of practically the entire body
of sulphuric acid, any portion escaping to the Gay-Lussac tower being there
absorbed by the strong sulphuric acid showered down upon the gases passing
thereto, as described.
By the manner of presentation set forth, all the gases and compounds reintro-
duced are, at the same time, intimately mixed with the freshly-entering gases
from the furnace or generators thereof, before their initial entry into the acid-
producing space of the apparatus. The operations described in connection with
this form of embodiment of the invention, and those hereinafter described, are
continuous and very rapid, and are additional to and independent of the regular
draft.
Referring to the second embodiment of the invention, illustrated in Fig. 3, the
same general arrangement of parts is employed as that shown in Figs. 1 and 2,
the difference residing in certain minor details of construction, and in the manner
n which the partially-spent gases from the rear of the apparatus are reintro-
luced to the system. The acid chamber E may, as already stated, be either a
ingle chamber, or two or more chambers connected by suitable passages or flues,
nd the lead chamber, as well as the cooling-chamber G may have therein com-
inuting or converting columns E2, G2, respectively, against which the gases
ill contact on their entry into the chamber or chambers and be precipitated.
t is to be understood that the converters F and the scrubbers I and J, or their
quivalents, may be used in connection with this form of device. In this second
mbodiment of the invention, the discharge-end of the flue N, which flue includes
e fan or blower M, instead of entering the flue K connecting the Glover tower
nd the lead chamber E, passes up through the bottom of the lead chamber,
ear its front end, and extends upwards therein and terminates at or near the
ane of the discharge-mouth of the flue K, and discharges across the path of the
coming gases from the generators, thereby effecting a thorough admixture of
e fresh and partly-spent gases, and a rapid and continuous precipitation of
phuric acid. The cooling chamber G may be connected with the rear portion
the acid-chamber through the converter F, thereby, if desired, dispensing with
e employment of the scrubber I, and against the packing of this converter F
e gases mixed by the fan or blower are forced or drawn by an artificial draft
ated either by a fan A2 in a flue leading from the furnace to the Glover tower;
a fan E3 in the flue connecting the Glover tower and the acid chamber; or
an I² in the flue connecting the lead chamber and the converters; or a fan G³

page_text: in the flue connecting the converter and the cooling-chamber; or a fan 0³ in
the flue connecting the rear portion of apparatus with the Gay-Lussac tower, or
in the exit thereof; or a fan D2 in the exit-flue above the Gay-Lussac tower.
It is to be understood that the circulation through the flue N may be in either
direction, and that the connections of this flue with the chamber or chambers
may be at either the top, bottom, side, or ends of the same.
It will be seen that the gases entering through the flue K, are met by the
gases drawn from the rear portion of the apparatus through the flue N; but it
is to be understood that interference with the ordinary or induced draft is over-
come by having any one of the fans in the flues mentioned stronger than the
fan which draws the gases from the furnace, otherwise, there would be no circu-
lation, and the materials would remain inactive in the chambers. It is also to be
understood, that a steam-injector or gas-pump may be employed in lieu of the
exhausters or fans in every position where the latter are used.
Referring to the third embodiment of the invention illustrated in Figures 4, 5
and 6, there is exhibited a modified form of mechanism for effecting reintroduc-
tion of the partially-spent gases, together with the freshly-entering gases from
the generators, into the lead chamber. In Fig. 4 the usual flue K connecting the
Glover tower and the lead chamber is employed; but instead of having the gases
from the generators pass directly through this flue into the said chamber, such
communication is cut off by a valve or damper ³, and the gases from the generators
are shunted through a branch-flue K2 tapped at one end into the flue K and at the
other end into the flue N leading from the rear of the apparatus, where it may
connect with the rear portion of the acid chamber; or, where converters are
employed, with these; or, with a series of packed chambers, alone, in place of
the ordinary chambers; or, with an open chamber, only; or, with a combination
of open chambers and packed towers. The point of connection between the
flue K2 and the flue N is somewhat removed from the fan M, so that the fresh
gases and partially spent gases are mixed before entry into the fan-casing, whence
they are projected through the flue L into the lead chamber. As in the other
embodiments of the invention, this projection of the materials causes a direct
suction or pull on the furnace and an advantageous pressure on the remainder
of the system. A draft-regulating damper 3 is placed in the flue K, and also
a damper 7 in the flue L, (as shown in Fig. 5), so that in case it should be neces-
sary to shut down the fan or blower for any length of time, the said damper can be
closed, and the damper opened, and the process can then be carried on in the
usual way by employing the natural draft.
In Fig. 5, the same general arrangement of parts is employed as that shown
in Fig. 4, with the exception that the flue K is dispensed with, and the flue K²
is extended from the Glover tower to and connects with the flue N. The opera-
tion of this apparatus is the same as that shown in Fig. 4.
In Fig. 6, the same general arrangement of parts is employed as that shown in
Figs. 4 and 5, with the exception that the flue K2 instead of being tapped into
the flue N, is tapped into the fan-casing, so that the initial mixture of the freshly-
entering and partially-spent gases takes place within the fan-casing, instead of
in the flue N, as is the case in the structures shown in Figs. 4 and 5.
Referring to the fourth embodiment of the invention, illustrated in Fig. 7,
there is exhibited a modified arrangement of the acid-producing portion of the
apparatus, wherein an acid chamber, such as employed in the other embodiments
described, is dispensed with. In lieu of the said chamber, a plurality of con-
verters F, similar to those shown in Figs. 1, 2 and 3, are employed, each con-
verter constituting, in itself, an acid chamber. The converters are connected
in series in the following manner. The first converter which may be of the
ordinary type, or, as shown, a Glover tower C, is connected by a flue with the
nitre ovens and the furnaces, as in the other embodiments described. Where a
Glover tower is used, there is provision made for showering nitrous vitriol through

page_text: it, as usual. At the upper portion of this first converter C is connected the flue K,
common to all the structures shown, which extends down and into the lower
portion of the next converter, and from the upper portion of this latter converter
extends a similar flue k to the lower portion of the next converter, and so. on,
throughout the series, the last converter having connected with it a flue O, which
may discharge into the open air, or may lead to a Gay-Lussac tower D, where one
is employed, as heretofore described. Connecting with the upper portion of the
last converter just described, is the flue N, as in the other apparatuses described,
which extends to the fan or blower M, the latter for causing a suction and pressure
through the apparatus, as herein before set forth. The fan-casing is provided
with a drip-pipe m for carrying off any acid condensed in the casing. Connecting
with the fan-casing is the flue L leading to the first of another series of converters,
which are connected in like manner as that described, and with the first series
by a flue f. It is to be understood that suitable drip or escape pipes f³, discharg-
ing into storage tanks, may be employed, or, if preferred, the discharge of the
acid may take place directly into carboys, or other suitable receptacles, as fast
as produced, and as this arrangement is obvious, illustration is unnecessary.
The necessary water for hydration is added to the system either by steam-jets f
entering the flues, or the converters near their bottoms, or by showering water
or weak sulphuric acid through the converter tops in the ordinary manner, through
pipes supplied from tanks f³, or by both methods.
The other parts of the apparatus herein shown, as the acid-eggs, acid-tanks,
and the compressor, for forcing acid to the top of the converters, Glover tower
and Gay-Lussac tower etc., are not described, as their operation is well under-
stood.
Having now particularly described and ascertained the nature of the said in-
vention as communicated to me by my foreign correspondent and in what manner
the same is to be performed I declare that what I claim is:-
―:
1. The apparatuses herein shown, substantially as described.
2. In an apparatus for manufacturing sulphuric acid, a generator for acid-
making materials, an acid-producing chamber or space connected with such
generator, a conduit or the like establishing communication between the rear
portion of the apparatus and the front portion thereof, and a blast-mechanism
included in the conduit and operating to project the partially-spent gases with-
drawn from the rear portion of the apparatus into direct contact with the freshly-
entering materials from the generator, substantially as described.
3. In an apparatus for manufacturing sulphuric acid, an acid chamber having
an entrance for supplying acid-making materials and an exit-opening, in combina-
tion with a blast-device discharging through the said entrance and mouthing
towards the exit-opening, for projecting the matter towards the exit-opening,
and a return for reintroducing a portion of the uncombined gases, substantially
as described.
4. In the manufacture of sulphuric acid, the method of effecting thorough com-
mingling of the gases, of exerting a direct pull or suction on the generator, and
of creating a desired pressure in an acid-producing space, which consists in
withdrawing a portion of the gases already generated, from a point towards the
rear of the apparatus, and leading them toward the front thereof, and then
mechanically projecting the gases into the acid-producing space in direct con-
tact with the freshly-entering materials from the generators, substantially as
described.
5. In the manufacture of sulphuric acid, the method of effecting a thorough
commingling of the gases, of exerting a direct pull or suction on the generator,
and of creating a desired pressure in an acid-producing space, which consists
in withdrawing a portion of the gases, already generated, from a point toward
the rear of the apparatus, and leading them toward the front thereof, and then
mechanically projecting the gases into the acid-producing space along and in

page_text: direct contact with the freshly-entering materials from the generators, sub-
stantially as described.
6. In the art of making sulphuric acid, the method of accelerating and in-
creasing the production within a given acid-producing space, which consists in
introducing materials into such space, causing agitation of the same, during
mixture and combination of the materials, and withdrawing a portion from, one
part of such space and representing it at another along and in direct contact
with the freshly-entering materials before their entrance into such space, sub-
stantially as described.
Dated thin 92nd
1000