IMPROVEMENTS IN THE MANUFACTURE OF CHLORINE
Year: 1852

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
WATSON PATTINSON, of Felling, New House, Gateshead, Manufacturing
Chemist, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Sixth day of April,
One thousand eight hundred and fifty-two, in the fifteenth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the
said William Watson Pattinson, my exors, admors, and assigns, Her special
licence, full power, sole privilege and authority, that I, the said William
Watson Pattinson, my exors, adiñors, and assigns, or such others as I, the
said William Watson Pattinson, my exors, admors, or assigns, should at any
time agree with, and no others, from time to time and at all times during the
term of years therein expressed, should and lawfully might make, use,
exercise, and vend, within England, Wales, and the Town of Berwick-upon-
Tweed, my Invention of "IMPROVEMENTS IN THE MANUFACTURE OF CHLORINE;"
in which said Letters Patent is contained a proviso that I, the said William
Watson Pattinson, shall cause a particular description of the nature of my
said Invention, and in what manner the same is to be performed, by an
instrument in writing under my hand and seal, to be enrolled in Her Majesty's
High Court of Chancery within six calendar months next and immediately
after the date of the said in part recited Letters Patent, as in and by the same,
reference being thereunto had, will more fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the
said William Watson Pattinson, do hereby declare that the nature of my
said Invention, and the manner in which the same is to be performed, are
fully described and ascertained in and by the following statement thereof,
reference being had to the Drawing hereunto annexed, and to the figures and
letters marked thereon, that is to say:-
That whereas on the Fourteenth day of July, One thousand eight hundred
and forty-six, I obtained Her Majesty's Letters Patent for "Improvements in
the Manufacture of Chlorine," and in the Specification of the said Patent I
describe and give Drawings of the still or vessel commonly in use for the
manufacture of chlorine, which, by reference to the said Specification and
Drawings, will be understood to consist of a double iron case, within which is
placed a stone vessel or still, with its shelf, cover, and stone pipe for introducing
steam into this stone vessel the charge of muriatic acid and oxide of
manganese is introduced, and the whole is heated up to a temperature of
about one hundred and eighty degrees Fahrenheit, by introducing steam into
the outer case, the operation being afterwards completed by the introduction
of steam at ten pounds per inch, or higher, among the residual materials
within the stone vessel or still now I have found in practice great incon-
venience and loss arise from the breaking of the stone vessel or still, and the
consequent escape of more or less muriatic acid into the space between its
outer surface and the inner surface of the iron steam case in which it is
placed, as well as great delay, inconvenience, and loss from the necessary
frequent renewal of the stone vessels themselves; my present Invention has
for its object the avoidance of this great loss, by permitting the use of the
stone vessels after they may have become cracked or broken in such a way as
would render them quite useless in the old mode of working which I have
just described. The method by which this is accomplished, and which
constitutes my Invention, is as follows:-I provide a case, consisting of
an external and internal iron vessel, shown at Figures 1 and 2, very similar to
the steam case described in the Specification already alluded to, except that
the inner iron case A, Figs. 1 and 2, instead of being whole, as formerly, is
perforated with a number of holes, shewn in the Figures. Into this perforated
iron plate the stone vessel B is placed, but the upper edge of the stone vessel
rises above the edge of the iron pan about 4 or 6 inches, as shewn in the
Figure. Around this projecting portion of the stone vessel or still is placed a
ring of iron a, a, Fig. 1, a little larger than the stone, so as to leave a space
of from to an inch all around, b, b, its flange resting upon the flange of the
inner iron pan and the outer iron pan. The inner iron pan and this ring are

page_text: irmly bolted together, as shewn, Fig. 1, and rendered water tight by cement.
The bottom of the space between the upper edge of the stone vessel and the
iron ring is covered with a strip of vulcanized india rubber c, c. A layer of
fire clay, of an inch thick, is pressed upon this, and the remainder of the
space b, b, filled with melted lead, which is then caulked, so as to render the
whole space c, c, between the outside of the stone vessel and the outer iron
pan steam or water tight under considerable pressure. Communicating with
this space by the pipe D is a small iron cistern E, 10 or 12 inches diameter
and three feet high, its upper edges being about two feet above the upper
edge of the stone vessel; and in this cistern is a lead pipe d, through which
steam may be passed so as to heat its contents when necessary, and this pipe
is continued and coiled quite round the inner iron pan in the space between it
and the outer one two or three times, as at d, d, Fig. 2, to where it issues at e,
at which point it is passed through the outer iron case, and the opening
secured by a flange, as shewn. The remainder of the arrangements of the
stone vessel or still, not being altered, it is needless to describe. On beginning
to work I run heated coal tar (which has been previously thickened by
boiling to such a degree as to be stiff when cold, but not brittle) into the
iron cistern E, until the whole of the space C between the outer iron pan and
the stone, and also the pipe, is completely filled in, and until the iron cistern
is nearly full. I then pass a current of steam through the lead pipe d, d, in
the iron cistern, and surrounding the inner iron pan A, by which the coal tar is
kept at a temperature near but slightly below its boiling point. I then charge
the still with muriatic acid and manganese, and afterwards proceed exactly in
the way detailed in the Specification of my former Patent already alluded to,
except that instead of using steam of 10 pounds within the still, I now use
steam of much higher pressure, the injury arising from the breaking of the
stone vessel, should it happen, being so much less. I have described the
still with a coil of pipe surrounding the inner iron vessel among the coal tar,
through which steam may be passed, so as to apply heat on the outside of the
stone vessel at first, in order to finish the operation by steam applied inter-
nally, as described in my former Patent; but this is not absolutely necessary,
for since steam of much higher pressure can be used without risk, there is less
danger of the muriatic acid being weakened by the condensation of the steam
than there is in the old method of working; and if the still is charged imme-
diately after a former charge is withdrawn there is no danger, as the still will
be quite hot enough to prevent any injurious condensation when steam of 20
or 25 lbs. is employed. It is, however, always essential to keep the small iron
cistern E pretty full of the thickened coal tar in a melted state, and the mode

page_text: in which this operates is obvious, for the pressure of the coal tar being into
the still, any cracks in the stone vessel are kept constantly full of coal tar, and
the tendency of this to pass inwards through these cracks effectually prevents
all leakage of acid into the iron case, while no disadvantage arises from the
passage of a little coal tar into the still. I prefer to work with a pressure of
about two feet, but this may be varied at the pleasure of the operator.
In describing my Invention I have confined myself to coal tar or thickened
coal tar as the material used for filling the interstice between the outer iron
pan and stone vessel, but many other substances will answer, as vegetable tar
or pitch, gutta percha, caoutchouc, different resins, oils, and fats capable of
being thickened by heat or otherwise, but coal tar is cheapest, and in many
respects best adapted to the purpose. I would, however, have it understood,
that I claim the surrounding a stone or earthen still or vessel with coal tar or
other suitable substance for the purpose and in the manner described when
used for the manufacture of chlorine.
In witness whereof, I, the said William Watson Pattinson, have hereunto
set my hand and seal, this Twenty-seventh day of September, in the
year of our Lord One thousand eight hundred and fifty-two.