IMPROVEMENTS IN THE MANUFACTURE OF HELICAL PIPES OF CLAY OR ARGILLACEOUS MATERIAL FOR CONDENSING OR REFRIGERATING VAPOURS OR LIQUIDS
Year: 1879

page_text: LETTERS PATENT to Ludwig Rohrmann, of Krauschwitz, in the Empire of
"
Germany, for the Invention of IMPROVEMENTS IN THE MANUFACTURE OF
HELICAL PIPES OF CLAY OR ARGILLACEOUS MATERIAL FOR CONDENSING OR
REFRIGERATING VAPOURS OR LIQUIDS."
Sealed the 11th November 1879, and dated the 13th May 1879.
PROVISIONAL SPECIFICATION left by the said Ludwig Rohrmann at the
Office of the Commissioners of Patents on the 13th May 1879.
LUDWIG ROHRMANN, of Krauschwitz, in the Empire of Germany. " IMPROVE-
MENTS IN THE MANUFACTURE OF HELICAL PIPES OF CLAY OR ARGILLACEOUS
MATERIAL FOR CONDENSING OR REFRIGERATING VAPOURS OR LIQUIDS."
This Invention relates to helical pipes or coils of clay of argillaceous material
used for the purpose of condensing vapours or distilling, or for refrigerating vapours
or liquids passed through them, and it has for its objects improved methods of
preparing the materials for making and of making such pipes.
I thoroughly dry the clay or argillaceous material which is to be used, and I then
reduce it to a fine powder and separate from it by sifting fragments of quartz,
feldspar, roots, or other substances.
The fine powder thus prepared is composed of the following materials :-Silicic
acid 67-45 per cent., argillaceous earth 20.56, sesqui oxide of iron 2.39, magnesia
074, water 576, alkali 3.10, all of which are more or less soluble in sulphuric
acid.
The clay compound consists of quartz powder 33.9 per cent., feldspar or other
mineral 13.24, and clay 52.86. The clay itself being composed of silicic acid 46-01
per cent., argillaceous earth 33.92, sesqui oxide of iron 4.52, magnesia 1.40, alkalis
3.25, and water 10.9.
I then take a feldspar composed as follows:-Silicic acid 63-21 per cent.,
argillaceous earth 22.93, sesquioxide of iron 0.45, limestone 3.62, lime 1.25, soda
845, and I first pulverize it and then reduce it to a very fine powder by grinding
it with the addition of water between quartz mill stones. I then separate the
water by decantation and dry the remainder, 20 parts of which I mix with sufficient
water to a thin fluid consistence and add to 80 parts of the dry clay powder first
described, the compound forming a soft dough or paste. I grind this paste between
Price di

page_text: two suitable granite stones forming a wet mill, until the principal part of the
contained water has been evaporated by the heat developed by the friction, so that
the mass can be formed into balls without becoming pasty, and I knead it in any
suitable form of mixing machine, and then form it into rolls which I cut into
pieces of convenient length.
These pieces are stored in a damp cellar until they are required for use, preferably
for about six months. I then take them and incorporate and knead them in a
machine constructed as follows:-
I take a vertical metal cylinder into the upper end of which the pieces are fed, a
vertical shaft being fitted in bearings and made to revolve in the centre of the
cylinder by steam or other suitable power. This shaft is provided with helically
arranged mixing blades or knives by which the clay is mixed and at the same time
is forced downward in the cylinder. At the lower end of the cylinder a helical
cutting screw or disc is fixed upon the shaft which forces the incorporated clay
out through a lateral opening, the mouth of which is of sinaller diameter than
the cylinder, into a horizontal pressing box or cylinder of the same diameter as the
Baid mouth.
This pressing chamber when filled contains a quantity of material sufficient when
it is placed horizontally into a press, by which the material can be forced out, to
form a hollow coil of pipe of the desired dimensions.
The delivery mouth of the pressing chamber is provided with a strong hollow
cone through the smaller end of which (representing the external diameter of the
pipe) the material is forced.
In the wider end of the cone is fixed a ring having three radial arms meeting in
the centre where they carry one end of a core bar, the other end of which is adjusted
within the smaller end of the cone and represents the internal diameter of the pipe.
As the material is forced forward it is divided by the radial arms, but re unites and
is discharged as a continuous pipe by passing through the annular space between
the end of the cone and the core bar.
The core bar may be adjusted in a position slightly excentric so that the annular
opening is narrower on that side on which the issuing pipe is bent automatically in
order to form a continuous coil.
If this. were not done the outer side of the pipe being stretched to form the coil
would not have sufficient substance to leave it of sufficient thickness.
The helically coiled pipe has its several bends or coils retained in their proper
position by vertical bars or supports of the same material, and the entire apparatus
so constructed may have its interior coated with any refractory glaze, and may
then be baked or burned at a very high temperature until vitrified, the outer side
being glazed in the well known way by means of salt.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Ludwig Rohrmann in the Great Seal Patent Office on the 13th
November 1879.
LUDWIG ROHRMANN, of Krawschwitz, in the Empire of Germany.
"IMPROVE-
MENTS IN THE MANUFACTURE OF HELICAL PIPES OF CLAY OR ARGILLACEOUS
MATERIAL FOR CONDENSING OR REFRIGERATING VAPOURS OR LIQUIDS."
This Invention relates to helical pipes or coils of clay or argillaceous material
used for the purpose of condensing vapours or distilling, or for refrigerating vapours
or liquids passed through them, and it has for its objects improved methods of
preparing the materials for making and of making such pipes.
I thoroughly dry the clay or argillaceous inaterial which is to be used, and I
then reduce it to a fine powder and separate from it by sifting fragments of quartz,
feldspar, roots, or other substances. The fine powder thus prepared is composed of
the following materials:-Silicic acid 67-45 per cent., argillaceous earth 20.56,
sesqui oxide of iron 2.39, magnesia 0.74, water 5.76, alkalis 3.10, all of which are
more or less soluble in sulphuric acid.
The clay compound consists of quartz powder 33.9 per cent., feldspar or other
mineral 13-24, and clay 52.86. The clay itself being composed of silicic acid 46-01
per cent., argillaceous earth 33.92, sesqui oxide of iron 452, magnesia 1·40, alkalis
3.25, and water 10.9.
I then take a feldspar composed as follows:- Silicic acid 63.21 per cent.,
argillaceous earth 22:93, sesqui oxide of iron 0.45, limestone 3.62, chalk 125, soda
8.45, and I first pulverize it and then reduce it to a very fine powder by grinding
it with the addition of water between quartz millstones. I then separate the water
by decantation and dry the remainder, 20 parts of which I mix with sufficient
water to a thin fluid consistence and add to 80 parts of the dry clay powder first
described, the compound forming a soft dough or paste. I grind this paste between
two suitable granite stones forming a wet mill, until the principal part of the
contained water has been evaporated by the heat developed by the friction, so that
the mass can be formed into balls without becoming pasty, and I knead it in any
suitable form of mixing machine, and then form it into rolls which I cut into pieces
of convenient length.
These pieces are stored in a damp cellar until they are required for use, preferably
for about six months. I then take them and incorporate and knead them in a
machine of which the accompanying Drawing is an illustration.
Figure 1 is a vertical section of the machihe. A is a vertical shaft driven by
steam or other power, and revolving in a vertical cylinder, into the upper end of
which the pieces are fed, and provided with helically arranged mixing blades or
knives C, C, C, by which the clay is mixed, and at the same time forced downward
in the cylinder; B is a helical cutting screw or disc fixed upon the shaft A, which
forces the incorporated clay out through a lateral opening, the mouth of which is
of smaller diameter than the cylinder, into a horizontal pressing box or cylinder D
of the same diameter as the said mouth.
The pressing chamber D, when filled contains a quantity of material sufficient,
when the chamber is placed horizontally into a press by which the material can be
forced out, to form a hollow coil of pipe of the desired dimensions.
The delivery mouth of the pressing chamber D, shewn in Figures 2 and 3, is
provided with a strong hollow cone H through the smaller end of which at J
(representing the external diameter of the pipe) the material is forced. In the
wider end of the cone H is fixed a ring having three radial arms h, h, h, meeting in
the centre where they carry one end of a corebar G, the other end of which is
adjusted within the smaller end of the cone at J, and represents the internal
diameter of the pipe. As the material is forced forward it is divided by the
radial arms h, h, h, but reunites and is discharged as a continuous pipe by passing

page_text: through the annular space at J between the end of the cone H and the core
bar G.
The corebar G may be adjusted in a position slightly excentric, so that the
annular opening at J is narrower on that side on which the issuing pipe is bent
automatically to form a continuous coil. If this were not done the outer side of the
pipe being stretched to form the coil would not have sufficient substance to leave it
of the proper thickness.
The finished coil made as above described in one piece is shewn at Figure 4, its
several bends or coils being retained in their proper position by vertical bars or
supports of the same material as shewn, and the entire apparatus so constructed
may have its interior coated with any suitable refractory glaze, and may then be
baked or burned at a very high temperature until vitrified, the outer side being
glazed in the ordinary well known way by means of salt.
Apparatus constructed according to my Invention has great capacity for resisting
internal pressure and changes and differences of temperature, and it also resists the
action of acid liquids or vapours. It may also be employed as a condenser in the
distillation of acids, such as acetic, muriatic, nitric, or sulphuric acids.
Having thus described my Invention, and the manner in which it is to be per-
formed, I claim,-First. The composition of the several ingredients in combination
with the method of preparing and manipulating such ingredients in the manufacture
of coils or helical tubes for condensing and refrigerating vapours or liquids, sub-
stantially as described.
Second. The kneading or mixing apparatus, the pressing chamber, and press, for
the purpose of manufacturing such coils or helical tubes, substantially as described
and shewn in the Drawing.
In witness whereof, I, the said Ludwig Rohrmann, have hereunto set my
hand and seal, this 11th day of November, in the year of our Lord 1879.