IMPROVEMENTS IN APPARATUS FOR OBTAINING SULPHUROUS ACID
Year: 1878

page_text: LETTERS PATENT to James Mactear, of Glasgow, in the County of Lanark,
North Britain, Chemist, for the Invention of "IMPROVEMENTS IN APPARATUS
FOR OBTAINING SULPHUROUS ACID."
PROVISIONAL SPECIFICATION left by the said James Mactear at the Office
of the Commissioners of Patents on the 19th September 1878.
JAMES MACTEAR, of Glasgow, in the County of Lanark, North Britain, Chemist.
"IMPROVEMENTS IN APPARATUS FOR OBTAINING SULPHUROUS ACID."
This Invention has for its object the obtainment of sulphurous acid in a better
and more economical manner than heretofore from pyrites or other sulphur ores or
compounds, when such materials are in the form of dust or in a granular or
powdered condition, in which condition they are unsuitable for treatment in the
ordinary "burners."
The improved apparatus, which may be built of materials usually employed in
such structures, is made with two or more compartments situated one above the
other; and separate charges of the sulphur-yielding materials are treated in the
several compartments, such charges being entered at different times, so that they
may be at different stages of the burning process, in order that a sufficient and
approximately uniform temperature may always be maintained throughout the
structure.
The hearths or floors of the several compartments are made each with a number
of separate stages or levels arranged helically, and descending in each case from the
one on which a charge is first entered to that from which it is finally discharged.
In a simple and convenient modification of the apparatus each hearth is made with
four stages or levels and the entire structure is square in plan. There is a central
pillar, and a vertical wall or partition extends from this pillar to the outer wall, so
as to separate the highest stages from the lowest stages of the several hearths.
Doors are formed in the outer walls on a level with and facing each stage of each
Pin G21

page_text: compartment, these doors being for introducing hand tools for transferring the
materials successively from each stage to the next lower one, the fresh charges of
materials being introduced at the highest door of each compartment. The spent
materials are discharged through ducts constructed in connection with the lowest
stage of each compartment, and the gaseous sulphurous acid passes into a main flue
by separate ports communicating with the several compartments at the highest
stage of each, so that the gas from the materials on the lower stages passes over
the materials on the higher stages, and its heat promotes the combustion of the
fresher materials.
The apparatus may be modified by making each compartment with more than
four stages or different levels; and the entire structure may be made with more
than four sides in plan, or it may be made of a circular or otherwise curved form.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
"
by the said James Mactear in the Great Seal Patent Office on the 17th March
1879.
JAMES MACTEAR, of Glasgow, in the County of Lanark, North Britain, Chemist.
IMPROVEMENTS IN APPARATUS FOR OBTAINING SULPHUROUS ACID."
My said Invention has for its object the obtainment of sulphurous acid in a
better and more economical manner than heretofore from pyrites or other sulphur
ores or compounds, when such materials are in the form of dust, or in a granular or
powdered condition, in which condition they are unsuitable for treatment in the
ordinary "kilns" or burners.
My improved apparatus, which may be built of materials usually employed in
such structures, is made with two or more compartments situated one above the
other; and separate charges of the sulphur-yielding materials are treated in the
several compartments, such charges being entered at different times so that they.
may be at different stages of the burning process, in order that a sufficient and
approximately uniform temperature may always be maintained throughout the
structure.
The hearths or floors of the several compartments are, in some modifications,
made each with a number of separate stages or levels arranged helically, and
descending in each case from the one on which a charge is first entered to that
from which it is finally discharged. Or instead of there being a distinct step or
abrupt descent from one stage to the next, the entire compartment may be made
with an inclination or gradual descent from the entering part to the discharging
part. In any case, whether with separate stages descending by steps or with a
general gradual descent, the descent does not require to be very great, and may
indeed be dispensed with altogether.
In one modification the structure is square in plan, and there is a central pillar,
from which a vertical wall or partition extends to the outer wall, so as to separate
the highest or entering part of each compartment from the lowest or discharging
part. Doors are formed in the outer walls on a level with and facing each stage or
part of each compartment, these doors being. for introducing hand tools, for
transferring the materials successively from each stage or part to the next lower
one, the fresh charges of materials being introduced at the highest door of each.
compartment. The spent materials are discharged through ducts constructed in
connection with the lowest stage or part of each compartment, and the gaseous
sulphurous acid passes into a main flue by separate ports, communicating with the
several compartments at the highest stage of each, so that the gas from the
materials on the lower stages passes over the materials on the higher stages, and its
heat promotes the combustion of the fresher materials.
My improved apparatus may be modified by making each compartment with
more than four stages or different levels, and the entire structure may be made
with more than four sides in plan, or it may be made of a circular or otherwise
curved form. It is sometimes inconvenient to arrange space on every side of the
structure for the workmen to get access to the doors for stirring and moving the
materials in the burners or hearths; and in such cases the structure may be of an
elongated form, with the compartments extending from one end to the other of it,
and with working doors along one side.
And in order that my said Invention and the manner of performing the same
may be properly understood I hereunto append two Sheets of explanatory
Drawings, to be herein-after referred to, and representing two modifications of my.
improved apparatus. In these Drawings the same reference numerals are used to
mark the same or like parts wherever they are repeated.
Figures 1, 2, and 3, on Sheet 1 of the accompanying Drawings, show a modi-
fication of my improved apparatus which is square in plan, Figure 1 being a

page_text: horizontal section as taken through one of the compartments, and Figures 2 and 3
being vertical sections as at the lines A-A, and B-B, respectively in Figure 1.
In this example there are three distinct compartments constructed one above the
other, and with a slight general descending inclination. A square pillar 1, occupies
the centre of the structure, and a wall 2 connects this with the outer wall, the
pillar 1 and wall 2 extending up through all the compartments. Doors 3, 4, 5, 6,
are formed on each of the four sides of the structure, there being a set of these
doors for each compartment. The fresh materials are introduced at each door 3,
which is at the higher side of the wall 2, and they are transferred at intervals by
means of hand tools introduced at the doors 3, 4, and 5, from each quarter of the
compartment to the next lower one successively. The gaseous sulphurous acid
passes off into a main flue 7 by ports 8, formed in the side wall and near each
entering door 3. At the lower side of the wall 2 there are three discharge outlets
or ducts 9, 10, 11, communicating respectively with the three compartments, and
beneath them there is a recess or pit 12 into which trucks may be run to receive
the spent pyrites or materials from the outlets, these materials being moved
towards and into the outlets by means of tools introduced at the doors 6.
The shallowness or small depth of the compartments is an important feature of
my improved construction, its purpose being to cause the gaseous currents which
pass through the compartments to do so as closely as possible to the materials
which are spread in comparatively thin layers. The precise depth may be varied
in different cases to suit the nature or peculiarities of the particular materials
intended to be operated on.
Figures 4, 5, 6, on Sheet 2 of the accompanying Drawings show a modification of
my improved apparatus which is of an elongated form, Figures 4 and 5 being
vertical sections as at right angles to each other, whilst Figure 6 is a horizontal
section as taken through one of the compartments. In this example there are four
compartments constructed one above the other, and these compartments are level
and extend from end to end of the structure, which may be of any length found
suitable or desirable in practice. Working doors 3-6 are provided along one side
of the structure, the fresh materials being introduced through the doors 3 close to
one end, and being moved along towards the other end by means of hand tools
introduced at the several doors. The gaseous sulphurous acid passes off into a
main flue 7 by ports 8 at the end where the materials are entered, and the spent
materials are discharged down a single flue 13 and duct 14 at the other end.
Having thus particularly described my said Invention and the manner of
performing the same, I have to state that I do not restrict myself to the precise
details herein described or delineated, but that what I believe to be novel and
original, and claim as the Invention secured to me by and in terms of the herein-
before in part recited Letters Patent is,-
The constructing of apparatus for obtaining sulphurous acid, substantially in the
improved manner herein-before described, and particularly the making of the
apparatus with a series of shallow compartments one over the other, such com-
partments being arranged and used for operating on separate quantities of
materials.
In witness whereof, I, the said James Mactear, have hereunto set my hand
and seal, this Fifteenth day of March, in the year of our Lord One
thousand eight hundred and seventy-nine.
JAMES MACTEAR. (L.S.)