Diphuric &cia.
Year: 1898

page_text: AS Diphuric &cia.
I, JACQUES LOUIS KESSLER, of Clermont Ferrand, Department of Puy-de-Dome,
in the Republic of France, Manufacturer of Chemical Products, do hereby declare
the nature of this invention to be as follows:-
This invention relates to an improved apparatus for concentrating sulphuric
acid by contact with heated gases.
The arrangements of this improved apparatus are such, that the cleaning of the
part called "saturex" and of the plates is facilitated. By way of explanation I
may mention that " saturex " means saturator," or 66
concentrator," and it is in
this portion of the apparatus that the concentration properly so called of the
sulphuric acid is effected. The plates are superposed slabs forming a column above
the saturex, said plates receive the acid to be concentrated and prepare the con-
centration by utilizing the lost heat of the saturex. Furthermore, the arrange-
ments of this improved apparatus are such that the said plates are of a simpler
construction, and ensure a more convenient maintenance, and that, consequently,
it is possible to treat in the said apparatus sulphuric acid, containing impurities,
such as the acid obtained from Glover's apparatus and that obtained by re-using
the residues from the acids of nitration of organic acids.
In order that this improved concentrating apparatus may be thoroughly under-
stood, also the advantages obtained in practice employing the said apparatus, I
will hereinafter fully describe the same.
The concentrating apparatus, comprises as the primitive device, a saturex,
receiving the acid to be concentrated and being subdivided in a number of chan-
nels in which the hot gases serving to produce the concentration circulate. These
gases enter by way of the flues and the conduit pass through the said circulating
channels, act upon the surface of the acid, escape below the partitions while
forcing the gases into a chamber and escape from the apparatus by way of a
chimney after having traversed a range of superposed perforated plates. These
plates receive the sulphuric acid prior to its introduction into the saturex and
permit of depriving the gases of the greater part of their heat before they leave the
apparatus through the chimney. The whole arrangement of the saturex and of
the column of plates is enclosed in a leaden jacket and the v hole rests upon a
metallic bed, supported by columns. Each plate is moreover furnished with a
hooked mounting permitting of removing the same. The leaden flanges of each
plate are soldered together in such a manner, as to form a continuous lead jacket.
The particular arrangements, with which the apparatus is provided are as
follows:-
The partitions of the saturex are formed according to the present invention by
moulding, with compressed materials of pumice moistened with a solution of an
alkaline silicate of 20 or 30° Beaumé, then dried and even more or less calcined,
whereas up to the present time they were formed of cut or chiselled stone. The
pumice may be substituted by silicious sand or by pulverized glass or crystal or
by a mixture of these different materials.

page_text: The longitudinal channels formed by these partitions, that is to say the circulat-
ing channels through which the gases enter as well as the feed-conduit leading to
the chambers have their ends provided with openings, which are respectively
closed by stoppers or plugs of refractory stone. These plugs, when put in place,
are cemented with clay; when they are removed, it is possible to introduce into
the channels a small fire-iron, then a small scraper, by the aid of which tools it is
easy, to detach deposits of any nature, that may have formed and that will obstruct
the said channels. At one of the ends of the saturex a transverse gutter is
arranged terminating in lateral openings each leading into a leaden conduit closed
by a leaden plate screwed by means of iron caps to the flange of the said conduit.
These lateral openings may be simply closed with plugs of stone which resist
the action of acids; but in this case it is preferable that the said plugs be exter-
nally covered with a leaden plate soldered on to the leaden jacket of the saturex
in order to avoid any chance of escape.
.
The detached deposits, above referred to, are collected in the gutter, in order
to be removed by means of a scraper or rake, through the suitably uncovered
openings. After the cleaning has been effected that is to say, after the saturex
has been freed from its deposits, the openings are re-closed, as above explained
and a physical washing operation is effected by means of water or a weak acid,
with which the saturex is filled up to its overflow level..
It should be understood that the openings in question may be provided upon
one side only or may be alternating from one side to another, instead of being
formed upon opposite faces.
When the cleaning has been effected, the apparatus is re-charged and again
started. It is preferable, that during the action an acid layer of about ten to
fifteen centimetres in height be maintained instead of keeping a layer of only
from five to eight centimetres, as has heretofore been the case. Under these con-
ditions the salines of sulphate of iron and of sulphate of alumina, which constitutes
the greater part of the deposits which are formed in--this layer, have time to
become granular and to swell. They are then carried away to a lesser degree
and owing to their immediate precipitation, they leave an acid clear and non-
turbid, contrary to what has been previously the case.
The plates of the apparatus are formed of slabs, in which lateral openings are
provided, which are closed by the aid of plugs of inattackable stone, which may
be covered by small plates of lead, soldered to the leaden outer jacket of the plates.
The openings in question serve to facilitate the cleaning of the plates and the
replacing of their inner pieces.
.
The plates each comprise for the discharge of the acids a piece of porcelain in
the form of a syphon forming at once an overflow and a hydraulic seal.
In a modified form of device the porcelain pieces of the device above described
are completely omitted. These pieces are substituted by a particular shape
imparted to the plates. These plates are here so cut at their upper part, as to
present a perimetrical flange and for each of the holes for the passage of the gases
a sloping flange. At their lower part cavities are provided, which lie exactly
above the passage holes of the lower plate and are formed not unlike caps or pans
serving to cause the gases to impinge against the surface of the liquid. It is
evident that the flanged passage holes may be combined with turned back porce-
lain caps or pans and that in this case the cavities provided higher up would be
omitted. In like manner the holes with flanges may be furnished with porcelain
for the purpose of guarding against rupture of the cut flanges. The plates in
this device are likewise provided with cleaning openings, closed by plugs and a
sight hole likewise closed by a stone plug.
The apparatus improved in all its parts in the manner stated, is then more
suitable for concentrating sulphuric acids, containing impurities of a nature such
as to cause deposits during the operation, more especially of acids obtained from
· Glover's apparatus and of those produced by the re-employment of residues
resulting from acids of nitration of organic substances.

page_text: These acids could, in fact only be concentrated in platinum vessels, which the
adherence of the produced deposits, caused to redden and to become carburetted,
and could neither be concentrated in glass or crystal vessels nor even in porcelain
vessels in which this adherence was a cause of rupture owing to inequality of
temperature. Kessler's primitive apparatus itself was not at all properly suitable
for their concentration in as much as the deposits could not be removed in an
industrial manner and the acids resulting therefrom readily became turbid. This
concentration could only be affected in cast metal vessels; but then, without
even speaking of the considerable and irregular wear of this metal caused by this
concentration, it produced black and turbid acids presenting no longer the out-
ward guarantees of purity, to which commerce rightly attaches so great an
importance.
Owing to the above improvements applied to Kessler's apparatus the acids
prepared with those obtained from Glover's apparatus or other residual acids,
treated by the said apparatus, become clearer in proportion as their degree of
density or richness in acid increases, to such a point as to compete with the purest
acids obtained from lead chambers.
The extension of the application of Kessler's apparatus, due to these improve-
ments permits of passing into Glover's apparatus the largest possible
amount of acid produced in chambers and to bring it in a hot condition into the
said apparatus, wherein it leaves its impurities, whilst formerly it was the recog-
nized practice to treat the smallest possible amount.
that the deposits would be less in the concentrating apparatus if the acid were
It goes without saying,
not brought in until after its cooling. However the increase of the deposits is
not so great as one would imagine, because the Glover apparatus does not become
so much soiled from the moment, when the acids leaving the same do not enter
the same in so large a quantity and when a larger quantity is brought in, while
omitting to add water thereto. It is in fact preferable, to substitute the latter
by acid obtained from the chambers. In this manner the washing of the con-
centrating apparatus will, with an incomparable facility, replace that of the
partly removed refrigeratories at the bottom of the Glover apparatus, also the
washing of the Glover apparatus itself. In any case the latter operation becomes
a much rarer occurrence, so that hand labour and cost of fuel are saved.'
Moreover, in the case of the employment of acids of 60 degrees Beaumé. I
have found, that the improved apparatus produces more than twice the amount of
acid of 66 degrees within the same time and at the same cost of fuel as in case
of feeding with acid from chambers, which varies between 50 and 54 degrees
Beaumé.
Moreover, in the case of the improved apparatus it is profitable to introduce
stronger acids than those obtained from chambers, and preferably hot acids. I
thus gain in fuel and save the purchase price of one apparatus in each two.
It should also be observed, that the use of the improved apparatus, under the
conditions above stated, in continuation of Glover's apparatus dispenses with the
production of an acid of 60 degrees at the bottom of the latter apparatus and that
it is even found advantageous not to go beyond 58 or 59 degrees at the outside.
In the description of the improved apparatus I have only mentioned the apparatus,
in which the concentration is effected; the accessory parts such as the gas suction
device, the devices for cooling the acid and for condensing small acids, also the
gas generator remain the same.
It should be understood that I reserve the right of applying only a portion of
The improvements described in one and the same apparatus.
Dated this 10th day of December 1898
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.

page_text: An Improved Apparatus for Concentrating Sulphuric Acid.
I, JACQUES LOUIS KESSLER, of Clermont Ferrand, Department of Puy-de-Dome,
in the Republic of France, Manufacturer of Chemical Products, 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:-
This invention relates to an improved apparatus for concentrating sulphuric
acid by contact with heated gases.
66
con-
The arrangements of this improved apparatus are such, that the cleaning of the
part called saturex" (by
"is here understood "saturator," or
saturex
centrator," and it is in this portion of the apparatus that the concentration
properly so called of the sulphuric acid is effected. The plates are superposed
slabs forming a column above the saturex, said plates receive the acid to be con-
centrated and prepare the concentration by utilising the lost heat of the saturex)
and of the plates is facilitated, that the said plates are of a simpler construction
and ensure a more convenient maintenance, and that, consequently, it is possible
to treat in the said apparatus sulphuric acid, containing impurities, such as the
acid obtained from Glover's apparatus and that obtained by re-using the residues
of acids from the nitration of organic acids.
.
In order that this improved concentrating apparatus may be thoroughly under-
stood, also the advantages obtained in practice by employing the said apparatus,
I will now fully describe the same with reference to the accompanying drawing,
in which;
Figure 1 is a vertical section through a concentrating apparatus constructed
in conformity with my invention, taken on the line 1-1 of Figure 2.
Figure 2 is a horizontal section through the said apparatus on the line 2-2
of Figure 1.
Figure 3 is a cross section on the line 3-3 of Figure 2;
Figure 4 is a plan, of one of the plates of this apparatus without mountings;
Figures 5 and 6 are vertical sections, drawn to a larger scale, taken respectively
on the lines 5-5 and 6-6 of Figure 4, with mountings.
The concentrating apparatus, represented in Figures 1, 2 and 3, comprises as
the primitive device a saturex, A, receiving the acid to be concentrated and being
subdivided into a number of channels a in which circulate the hot gases serving
to produce the concentration. These gases enter by way of the flues B and the
conduit b, pass through the said circulating channels a act upon the surface of the
acid, escape below the partitions C, into the chamber D, and escape from the
apparatus by way of the chimney E after having traversed a range of superposed
perforated plates F. These plates receive the sulphuric acid prior to its intro-
duction into the saturex and permit of depriving the gases of the greater part of
their heat before they leave the apparatus through the chimney E. The whole
arrangement of the saturex and of the column of plates is enclosed in a leaden
jacket and the whole rests upon a metallic bed, supported by columns P. Each
plate is moreover furnished with a hooked mounting permitting of removing the
same. The leaden flanges of each plate are soldered together in such a manner,
as to form a continuous leaden jacket.
The particular arrangements, with which the apparatus is provided, are as
follows:
The partitions C of the saturex are formed according to the present invention
by moulding, compressed pumice stone moistened with a solution of an alkaline
silicate of 200 or 30° Beaumé, they being then dried and more or less calcined,

page_text: up to the present time they were formed of cut or chiselled stone. The
pumice stone may be substituted by sand or by pulverized glass or by a mixture
of these materials.
The longitudinal channels formed by these partitions C, that is to say the circu-
5 lating channels a, through which the gases enter, as well as the feed conduits a¹
have their ends provided with openings, which are closed by stoppers or plugs 61 of
refractory stone. These plugs, when put in place, are cemented with clay; when they
are removed, it is possible to introduce into the channels a a¹ a small rake, then
a small scraper, by the aid of which tools it is easy, to detach deposits of any
0 nature, that may have formed and that will obstruct the said channels. At one
of the ends of the saturex a transverse gutter d is arranged terminating in lateral
openings d', each leading into a leaden conduit closed by a leaden plate el, screwed
by means of iron caps to the flange of the said conduit. These lateral openings
may be simply closed with plugs of stone which resist the action of acids;
5 in this case it is preferable that the said plugs be externally covered with a leaden
but
plate soldered on to the leaden jacket of the saturex, in order to avoid any chance
of escape.
The detached deposits, above referred to, are collected in the gutter d, in order
to be removed by means of a scraper, through the suitably uncovered openings d¹.
After the cleaning has been effected that is to say, after the saturex has been freed
from its deposits, the openings are re-closed, as above explained and a washing
operation is effected by means of water or a weak acid, with which the saturex is
filled up to its overflow level.
It should be understood that the openings in question may be provided upon one
side only or may be alternating from one side to another, instead of being formed
upon opposite faces.
When the cleaning has been effected, the apparatus is re-charged and again
started. It is preferable, that during the action an acid layer of about ten to
fifteen centimetres in height be maintained instead of keeping a layer of only
from five to eight centimetres, as has heretofore been the case. Under these
conditions the salts of sulphate of iron and of sulphate of alumina, which consti-
tute the greater part of the deposits which are formed in this layer, have time to
become granular and to swell. They are then less liable to be carried away and
owing to their immediate precipitation, they leave an acid clear and non-turbid,
contrary to what has been previously the case.
The plates F of the apparatus (Figures 1, 2, 3, 4, 5 and 6) are constituted by
means of slabs internally recessed in the form of troughs, the bottom of which is
perforated with a certain number of oval apertures i.
cemented porcelain parts of oval section 1. Each of these parts, which are termed
Into these apertures are
supports, is surmounted by another part of the same material and which are
ermed "caps." These caps serve to direct the gases which come from the saturex
or from the lower plates, traversing the bottom of the said plate by way of the
pertures i and the supports, into the acid contained in the trough and there
vash them; the said caps are of the form of oval saucers having notched edges
nd they are of a section greater than that of the supports. They present a pro-
ection at about one fourth the length of their greater diameter, starting from
ach extremity. The two projections upon each cap serve to maintain this latter
a place and to leave between the cap and the support a space for the passage of
he gases.
In addition to the apertures i for the supports, the plates are perforated with a
ecial aperture in which is cemented a retrogradation cup h consisting of a
orcelain cup m, in the bottom of which is a central projecting tube m', and of a
ell of the same material m³ which is notched upon its edges; this bell is dis-
aceable. It is through this cup m, which forms a liquid seal joint, that the acid
ws from the upper plate upon the lower plate or upon the saturex. This cup
arranged in such a manner that the level of the acid in the plate may be such
to ensure a thorough washing of the gases.

page_text: ר
Finally, upon the vertical sides of the plates F are formed apertures which are
closed by means of plugs g of non-attackable stone, which may be covered with
small plates of lead soldered to the external leaden casing of the plates. The
apertures in question are intended to facilitate the cleansing of the plates and the
replacement of their internal parts.
C
The apparatus improved in all its parts in the manner stated is then more
suitable for concentrating sulphuric acids containing impurities of a nature such
as to cause deposits during the operation more especially of acids obtained from
Glover's apparatus and of those produced by the re-employment of residues of
acids resulting from the nitration of organic substances.
f
These acids could, in fact only be concentrated in platinum vessels, which the
adherence of the produced deposits, caused to redden and to become carburetted,
and could neither be concentrated in glass or crystal vessels nor even in porcelain
vessels in which this adherence was a cause of rupture owing to inequality of
temperature. Kessler's apparatus described in the specification attached to Letters
Patent No. 19215 of 1891 was not at all properly suitable for their concentration
in as much as the deposits could not be removed in an industrial manner,, and the
acids resulting therefrom readily became turbid. This concentration could only
be effected in cast metal vessels; but then, without even speaking of the consider-
able and irregular wear of this metal caused by this concentration, it produced
black and turbid acids presenting no longer the outward guarantees of purity, to
which commerce rightly attaches so great an importance.
Owing to the above improvements applied to Kessler's apparatus the acids
prepared with those obtained from Glover's apparatus or other residual acids,
treated by the said apparatus, become clearer in proportion as their degree of
density or richness in acid increases to such a point as to compete with the purest
acids obtained from lead chambers.
The extension of the application of Kessler's apparatus, described in the speci-
fication forming part of Letters Patent No. 19215 of 1891 due to these improve-
ments permits of passing into Glover's apparatus the largest possible amount of
acid produced in the chambers and to bring it in a hot condition into the said
apparatus, wherein it leaves its impurities, whilst formerly it was the recognized
practice to treat the smallest possible amount. It goes without saying, that the
deposits would be less in the concentrating apparatus, if the acid were not brought
in until after its cooling. However, the increase of the deposits is not so great
as one would imagine, because of the Glover apparatus not becoming so much
soiled owing to the fact that the acids which leave the same do not re-enter in
so large a volume and thus it will be possible to pass a larger quantity through
the apparatus without adding water thereto. It is in fact preferable to substitute
the latter by acid obtained from the chambers. In this manner the washing of
the concentrating apparatus will, with advantage, replace the refrigerating agents
at the bottom of the Glover apparatus, also the washing of the Glover apparatus
itself. In any case the latter operation becomes a much rarer occurrence, so that
hand labour and cost of fuel are saved.
Moreover, by employing acids of 60 degrees Beaumé, I have found that the
improved apparatus produces more than twice the amount of acid of 66 degrees
within the same time and at the same cost of fuel as in case of charging it with
acid varying between 50 and 54 degrees Beaumé.
Moreover, in the case of the improved apparatus it is profitable to introduce
stronger acids than those obtained from the chambers, and preferably hot acids.
I thus gain in fuel and save the purchase price of one apparatus in each two.
It should also be observed, that the use of the improved apparatus, under the
conditions above stated, in continuation of Glover's apparatus, dispenses with the
production of an acid of 60 degrees at the bottom of the latter apparatus and
that it is even found advantageous, not to go beyond 58 or 59 degrees at the outside.
It should be understood that I reserve the right of applying only a portion of
the improvements described in one and the same apparatus.

page_text: Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
1. An improved apparatus for concentrating sulphuric acid, characterized as a
whole; by a saturex A the longitudinal channels of which are so arranged, as to
admit of the operations of scraping and removing the deposits forming thereon;
by the contsitution of the partitions C, forming the said longitudinal channels,
by the aid of mouldings or the like; and by plates F so arranged, as to facilitate
their cleaning and the retrogradation of the acid obtained from Glover's apparatus
or of other residual acids, or of successive regenerations, in the manner and under
the conditions indicated.
2. The method of employing the improved apparatus, forming the subject of
the first claim, under the following conditions;
(a) Increase of the layer of acid within the saturex;
(b) Combination with the Glover apparatus in the manufacture of sulphuric
acid;
(c) Systemic feed with acids more concentrated than acid obtained from
chambers.
Dated this 11th day of September 1899
HASELTINE, LAKE & Co.,
45, Southampton. Buildings, London, W.C.,
Agents for the Applicant.