AN IMPROVED PROCESS AND APPARATUS FOR MANUFACTURING NITRO-GLYCERINE
Year: 1871

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine,
Lake, & Co., Patent Agents, Southampton Buildings, London,
for the Invention of "AN IMPROVED PROCESS AND APPARATUS FOR
MANUFACTURING NITRO-GLYCERINE."-A communication from abroad by
COMPLETE SPECIFICATION filed by the said William Robert Lake
at the Office of the Commissioners of Patents, with his Petition
and Declaration, on the 20th May 1871, pursuant to the 9th Section
of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London, send greeting.

page_text: petitioned Her Majesty to grant unto me, my executors, administrators,
and assigns, Her Royal Letters Patent for the same, and have made
solemn Declaration that it has been communicated to me from abroad
by Henry D. Berrett, of Washington, District of Columbia, United States
of America.
NOW KNOW YE, that I, the said William Robert Lake, do hereby
declare that the following Complete Specification, under my hand and
seal, fully describes and ascertains the nature of the said Invention,
and in what manner the same is to be performed, in and by the following
statement, reference being had to the accompanying Drawing forming a
part of this Specification :-
Nitro-glycerine is made of a mixture of nitric acid and glycerine, and
has heretofore been manufactured by pouring the glycerine (of 30°
gravity) and mixed acids composed of one part nitric acid (of 48° gravity)
with two and six one hundredth parts of sulphuric acid (of 66° gravity,
oil of vitriol), in the proportion of one pound of glycerine to nine pounds
of mixed acids in separate streams of mixed acids and glycerine into
water, the streams uniting and forming nitro-glycerine. Other plans of
mixing have also been used.
One great disadvantage of these methods is that water is rapidly
formed by the combination of oxygen and hydrogen in the chemical
reaction, and that the nitro-glycerine is apt to decompose by the
formation of other chemical combinations, and that a dangerous degree
of heat is apt to be generated. There is also a great loss of the acids
employed by the dilution effected by pouring them with the glycerine
into a water bath.
By my improved process and the apparatus which I employ I secure
the combination of a greater proportionate quantity of the glycerine and
nitric acid; I preserve a lower and safe temparature; and I also by
dispensing with the water bath effect a great saving of the mixed acids.
Another method in use is to pour the glycerine into a bath of mixed
acids, and agitate the contents by a churning action; but even in this
method, although there is not the same loss of acid, there is too great a
heat generated, and the acid is apt to decompose.
My improvement consists in keeping up a constant and regular cir-
culation of the fluid contents of the vessel in which the nitro-glycerine is
made by the pouring of glycerine into a bath of mixed acids, whereby

page_text: DESCRIPTION OF THE DRAWINGS.
Figure 1 is a top view of my apparatus; Figure 2 is a vertical trans-
verse section on the line a, a, Fig. 1; Figure 3 is a longitudinal vertical
section on the line y, y, Fig. 1; Figure 4 is a modification of the
apparatus shown in the other Figures. In Figures 1, 2, and 3, like
letters of reference denote similar parts of the apparatus.
a is a wooden tank or vessel of any size according to the capacity
desired, preferably of rectangular shape, and capable of holding water.
Inside of this tank a is a leaden mixing vessel b of the same shape as
the tank a, but a little smaller, which is supported by feet c, c, or
otherwise in such a manner as to leave a water space all around and
under the bottom of the mixing vessel b, so that the leaden mixing
vessel may be surrounded by water, excepting at the top, a space of one
or two inches between the tank a and mixing vessel b, being ordinarily
sufficient. One or more flues or diaphragms d, d¹, extend horizontally
from side to side of the mixing vessel b, opening with the water space,
so that water may flow through it or them. These diaphragms are made
of lead, and being liable to collapse are supported by leaden pipes i, i,
placed side by side through the diaphragms extending across within the
diaphragms, and also opening at each end into the water space of the
tank a.
If preferred the pipes or tubes i, i, may be used alone in place
of the diaphragms. If more than one diaphragm is used they are
placed horizontally one above the other, and a short distance apart. A
water pipe e admits a stream of cold water into the tank a outside of the
mixing vessel b at or near the bottom, and an overflow pipef at or near
the top allows the water to escape. If a sufficient head of water is
attainable the overflow pipe ƒ passes over an overshot water wheel g
placed to one side of the tank a, which turns the paddle wheel h
attached to the shaft j, which shaft extends through bearings placed
horizontally across the tank near one end of the same. The paddle
wheel h dips into the mixing vessel b, and by its revolution creates and
sustains a rapid current or circulation of the fluid contents of the mixing
vessel. If the power of the waste water is for any reason inapplicable to
turning the paddle wheel it must be kept in revolution by some prime

page_text: motor at the rate of about twenty revolutions per minute. The water
should flow rapidly through the water space between the tank a and
mixing vessel b, and through the diaphragms d, d', so as to keep down
the temperature of the contents of the mixing vessel. A discharge
pipe at the bottom of the mixing vessel 6 extends through the tank a
to the receiving tank 1, which contains water (see Fig. 3), and it is
furnished with a cock n. Through the pipe & the manufactured nitro-
glycerine, together with the residual mixed acids, are discharged into
the tank 1, where the acids mixed with the water and the nitro-glycerine
sink to the bottom. A vessel m containing glycerine (at about 30°
gravity) is placed conveniently over the mixing vessel b, from which the
glycerine is allowed to run in a constant small stream through a funnel o
into the acids in the mixing vessels. A thermometer p is inserted through
the cover of the mixing vessel, the bulb extending into the fluid
contents of the vessel, so as to indicate the temperature. On the shaft j
of the water wheel g and paddle wheel are placed two disks r, r, on
cach side of the paddle, which prevent any of the mixed acids or nitro-
glycerine in the mixing vessel from reaching the journals of shaft j.
The mixing vessel 6 has a leaden cover q which extends over the vessel,
having a semi-cylindrical projecting cap to cover the paddle wheel h.
An opening in the cover q for inserting the mixed acids into the
mixing vessel 6 has a separate lid u. In order to permit the convenient
emptying of the tank, the end at which the discharging pipe k is situated
is set a little (say, one inch, more or less,) lower than the other end.
The operation of this apparatus and the process employed by me in
the manufacture of nitro-glycerine are as follows:-The mixing vessel b
is filled to within about three inches from the cover with mixed acids of
the strength and in about the proportions before stated, the exact pro-
portions stated not being essential, but being such as actual experience
has proved to be suitable. The cold water being let on through the
water pipe e passes rapidly and constantly through the water space
around the mixing vessel b, and through the diaphragms or pipes i, i.
A small stream of glycerine is allowed to run through the funnel o into
the mixing vessel and the paddle h creating a constant and rapid current
throughout the entire fluid contents of the mixing vessel causes the
glycerine and mixed acids to flow in the direction indicated by the
arrows in Fig. 3 under the paddle h, and thence under the diaphragm
d, d, toward the other end of the vessel where they rise over the

page_text: diaphragms, and again passing under the paddle h are thus kept in
constant and rapid circulation, and become intimately commingled, tho
glycerine combining with the nitric acid to form nitro-glycerine. When
the charge is thoroughly mixed the contents of the mixing vessel are
run into the receiving tank 7, as before stated, where the acids mixing
with the water in the tank are separated from the nitro-glycerine which
sinks to the bottom.
A modification of my apparatus is shewn in Figure 4, consisting of an
outer water tank v surrounding a leaden mixing vessel w with a water
space all around between them.
Diaphragms x, x³, extend along or across the interior of the mixing
vessel in a vertical position, and communicate at each end with the
water space surrounding it. An inlet water pipe y and an overflow or
outlet pipe y¹ serve to furnish a constant current of cold water through
the water space between the water tank and mixing vessel w, and
through the diaphragms x, x¹. The mixing tank w has a discharging
cocks at the bottom. A revolving paddle z fixed on a vertical shaft z¹
and moved by any convenient means, has its seats so set as to cause a
downward flow of the fluid contents of the mixing vessel w which pass
under the diaphragms x, x¹, and thence upward between them and the
sides of the mixing vessel; or the flow may by reversing the paddle be
made to ascend in the middle between the diaphragms, and thence pass
downwards between the diaphragms and the sides of the mixing vessel.
Thus as the glycerine flows in a constant small stream into the mixed
acids in the vessel w a constant current is maintained, and the thorough
combination of the acid and glycerine is effected.
By means of the process which I have above described I procure a
larger yield of nitro-glycerine, and the temperature of the contents of
the mixing vessel is prevented from rising to a dangerous degree.
Having thus described my said Invention as communicated to me by
my foreign correspondent, and shown how the same may bé conveniently
and advantageously carried into practice, I claim, -
First. The process of mixing glycerine and mixed acids to form
nitro-glycerine by introducing the glycerine into a bath of mixed acids
(nitric and sulphuric) in which a rapid circulation of the fluid contents
of the bath is maintained, substantially as and for the purposes
described.

page_text: Second. The apparatus herein-before described for the manufacture
of nitro-glycerine, consisting of a mixing vessel having a diaphragm
or diaphragms in combination with a paddle wheel for creating and
sustaining a rapid circulation of the fluid contents of the mixing vessel,
substantially as and for the purposes herein-before described.
Third. The mixing vessel traversed by hollow diaphragm or dia-
pbagms communicating with an exterior and surrounding vessel or
reservoir of water for the purpose of making nitro-glycerine, substantially
as herein-before described.
In witness whereof, I, the said William Robert Lake, have here-
unto set my hand and seal, this Twentieth day of May, in the
year of our Lord One thousand eight hundred and seventy-one.
Witness,
W. J. LOWE.
WILLIAM ROBERT LAKE. (L.S.)