Improvements in and connected with Furnaces.
Year: 1892

page_text: Date of Application, 27th Oct., 1892-Accepted, 31st Dec., 1892
COMPLETE SPECIFICATION.
Improvements in and connected with Furnaces.
I ALFRED HORATIO NELSON of Sherland Works, Station Road Twickenham
Middlesex Scientific Instrument Maker do hereby declare the nature of this inven-
tion and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement :-
The object of this invention is the production of an intense heat by the com-
bustion of petroleum spirit vapour under pressure, for the assay and fusion of ores
and metals at high temperatures, for cremation, and for various operations in the
arts and sciences where an intense heat is required.
The vapour is produced and the desired pressure maintained automatically
according to the strength of blast required without the use of pumps, foot blowers
or fans.
The construction and arrangement of the different parts of this apparatus are
shown in the drawings hereunto annexed.
Figure 1 shows back view of flat form of vapourizer, chiefly for horizontal
blasts when using portable furnaces. The dotted lines indicate the borings through
the metal, with inlet for petroleum spirit at A and outlets for the vapour at B
and C.
The borings are securely closed at the sides with screw plugs.
This portion of the apparatus I construct preferably of gun-metal, and in size
according to power and volume of blast required.
For laboratory and workshop use, flat vapourizers from about four inches square
and about half an inch thick are a convenient size. For cremation and other
operations requiring a blast of greater volume the apparatus is increased in size in
proportion to the work it is intended to do.
Figure 2 (partly in section) shows side view of flat vapourizer, with blast tube
and air regulator attached; and with furnace, petroleum spirit tank, taps, unions,
tubing and pressure gauge in their relative positions when in use.
The action of the apparatus is as follows. Tank J is filled with petroleum
spirit and the stopper O securely screwed down. The vapourizer receives a primary
heating with the small hand blast Fig. 5. Tap M is fully opened, and tap L
gradually opened, when the petroleum spirit passing through tube K enters the
vapourizer at A. Fig. 1 where it is rapidly converted into vapour. One portion of
the vapour passes through B Fig. i into the nozzle when it is driven forward
through the blast tube F where it is ignited, and on into the furnace at G. The
supply of air is regulated by the perforated loose collar on socket at H.
The remaining portion of vapour passes from the vapourizer at C Fig. 1 and is
conducted by tube I Fig. 2 to upper part of tank J through tap M.
The pressure in tubes I and I Fig. 2 being equal, and the bottom of spirit tank
being about level with top of vapourizer, the supply of the liquid fuel is maintained
automatically by gravitation, and in quantity as may be desired by opening or
closing tap L Fig. 2. The heat produced in the blast tube maintains the
temperature of the vapourizer sufficiently high to supply the necessary quantity of
petroleum vapour.
A gauge to indicate the pressure at which the vapour is being driven through
the blast tube communicates with tank J through the cross way of tap L.
J Fig. 2 shows the tank for holding the petroleum spirit. This tank may be of
any convenient capacity from half gallon upwards, and is a stout cylinder of copper,
brass, steel or other suitable metal, with inlet on top for filling, closed by a well
fitting screw stopper O, and with bosses at top and bottom of side for attaching
fluid and vapour taps.

page_text: Tubes I and K I construct preferably of soft copper, the diameter of bore
being in proportion to the size of the apparatus, and commencing at
smaller sizes.
inch for the
The blast tube F Fig. 2 I construct in separate parts, viz.-an iron nipple which
passes freely through hole in centre of vapourizer and held on the front, or furnace
side by an iron nut and on the opposite side by a reducing socket. This socket is
pierced with a number of holes in the shoulder and also on the side, as shown in
drawing at H. On this reducing socket a loose collar of gun metal or brass is
fitted, being also pierced with holes corresponding to those in the reducing socket,
the spaces between the holes being a little more than the diameter of the holes.
A pin is attached to the narrow part of the collar by which the latter may be
moved so as to regulate the admission of air through the holes in the socket or to
close the holes as may be necessary according to the draught of air required. In
the small end of reducing socket-which is the permanent opening for the
entrance of petroleum spirit vapour to the blast tube-a nipple may be used to
decrease the aperture through which the vapour passes when working at low
pressure.
E shows the nozzle holder, constructed preferably of gun metal or brass, and
which is connected to the vapourizer at B (Fig. 1) by brass or iron tube as shown
in drawing, the dotted lines in E showing the boring through which the vapour
passes to the nozzle. The nozzle is pierced with one or more very small holes.
The vapour is driven in the direction of the small arrow-head, through the blast
tube F into the furnace at G.
With the ordinary blast as described, gold, silver, copper, cast iron, nickel &c.
are easily and quickly melted. When, however, extremely high temperatures are
required for the treatment of some of the more refractory substances, I introduce
a jet of oxygen gas to the furnace along with the petroleum vapour,
The oxygen
may be used direct from the cylinders as supplied commercially, or made as required
by any of the well known methods.
Figure 3 shows the coil form of vapourizer which I construct by winding a copper,
tube of suitable size round the outside of blast tube. This form may be used in
any position or at any angle that may be required for special metalurgical, chemical
or other operations. The arrangements for supply of petroleum spirit from tank
and regulation of air draught being substantially the same as those herein described
in relation to the flat form of vapourizer.
Figure 4 shows plan of the portable fire clay furnace which I construct in sections
of suitable dimensions according to circumstances, the sides of the sections being
concave and convex respectively. The advantage of this form is that a section
may be removed, or a section added so as to reduce or increase size of furnace as
may be required, the convex edge of one section fitting into the concave edge of
another and forming a close joint. The sections are held in position during use by
a light chain and clip at top and bottom,- -as shown in vertical perspective
sketch 4" and stand on a fire clay base, having a fire clay top with a central hole
for manipulating contents of furnace when in operation. A fire clay cap covers
the hole in top when required.
For the purpose of cremation the portable furnace is constructed of fire clay
slabs of suitable size form and thickness according to size of chamber required,
and arranged on a light iron framework as illustrated by Figure 8. The joints of
the fire clay slabs I construct as shown at 8 in which the edges of the slabs are
grooved and asbestos rope laid in the grooves which when pressed together make
thoroughly fire proof joints. Each end is free for the opening and closing of the
chamber. I use a double blast of large volume, one being placed at each side of
the chamber. In an extremely short time the combustion of everything placed
within the furnace is complete, nothing but clean ashes being left.
This arrangement mounted on a suitably constructed carriage is easily transported
from place to place.
41

page_text: Figure 5 shows section of small automatic hand blast for the primary heating of
the vapourizers, and for various blowpipe operations.
I construct the body of this portion of the apparatus of brass or copper, the top
and bottom being concave on the outside. In the top I insert and solder a copper
tube & Fig. 5, about two thirds the length of the body; within this tube is another
tube leaving a space of about 1inch between the tubes. These two tubes are
soldered to an intermediate ring at bottom of the inch space, leaving the inner
tube open at bottom. In the top of inner tube is fitted the vapour nozzle. A third
tube c, which acts as a blast tube and heat conductor, slides into the inch'space
between the two tubes aforesaid, the length of the blast tube being double the
length of the aforesaid space. This blast tube is pierced with holes of different
shape and size in each half of its length and may be reversed so as to alter the
shape of Hame.
•
In the bottom I fix a tap d similar in construction to those used on spirit tank
as aforesaid, to control the flame as may be desired, the wheel of the tap acting as
a foot when used vertically. 1 place an inlet for charging preferably at the side,
with-screw stopper also a boss on side into which a handle is screwed.
To use this hand blast the petroleum spirit is introduced at the inlet, the stopper
screwed down and the tap at bottom opened. It is then placed in an upright
position and the blast tube passed down into its place. A little spirit is poured
into the concave top and lighted, while burning off, this heats the metal which
vapourizes the spirit rapidly, producing the required blast.
•
Figure 6 shows a section of improved tap made in brass or gunmetal for use in
this apparatus and which I. construct as follows-a a Fig. 6 is a conical aperture
into which is fitted accurately the cone, shaped stopper bb, this stopper having a
raised screw cc working in a corresponding screw at
d, e
is a stuffing box packed
with asbestos, with ring at bottom resting on screw, and secured with pressure
ring and screw cap at f. Ordinary wheel or lever handle on outside end of
stopper.
These taps may be used in various positions being provided with crossways, and
are perfectly effective under very high pressures of liquid or vapour. I lubricate
the asbestos packing with black lead and glycerine.
Figure 7 shows section of improved union for connecting vapourizer with spirit
tank (by tubes I and K Fig. 2).
I make a conical seating in one portion of union at a into which the cone of the
other portion at is accurately fitted and ground.
The loose screwed collar c is provided with lugs, and on the other part corre-
sponding lugs for convenience of easily coupling or uncoupling the unions. These
unions are also perfectly sound under very high pressures of liquid or vapour.
The portable stands used for the furnace, the vapourizer, and the tank in this
apparatus are shown at Pa Pb pc Fig. 2. P is a flat ring of suitable diameter to
which are attached three legs, these being removable for packing, or secured in
their places by suitable bolts and nuts. Pb and P have folding feet as shown in
illustrations. The upright tubes to which they are secured by nuts above and
below, receive the sliding rods which support the vapourizer and tank respectively,
and are held in position by thumbscrews at the sides.
Figure 8 shows sperspective view of portable cremating chamber-furnace as
hereinbefore described, with one end removed.
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) The construction of portable automatic smelting blast and furnaces sub-
stantially as hereinbefore described and illustrated in the drawings annexed.
(2) The forms of vapourizers substantially as described for rapidly converting
the petroleum spirit into vapour.

page_text: (3) Conducting a portion of the petroleum vapour from the vapourizer to the
upper part of the spirit tank thus equalizing the pressure at all points and
allowing the spirit to pass into the vapourizer by gravitation substantially as
described.
(4) Conducting the other portion of the petroleum vapour to the burner nozzle
and thence through the blast tube to the furnace substantially as described.
(5) The combination of parts forming the blast tube and air regulator sub-
stantially as described.
(6) The construction of improved taps substantially as described for controlling
the passage of petroleum spirit or vapour under pressure.
(7) The construction of improved unions substantially as described for securely
connecting the spirit tanks with the vapourizers by their respective tubes.
The portable furnace in curved sections substantially as described.
The small. hand blast for primary heating of vapourizers and for other
purposes substantially as described.
(10) The admission of a jet of oxygen gas to the furnace in conjunction with
the petroleum spirit vapour when extremely high temperatures are required for
the treatment of refractory minerals, and metals having a very high fusing
point.
(11) The use of this portable automatic blast and chamber-furnace for the
purpose of cremation, this system being swifter, cleaner, and more economical than
when performed with solid fuel in the ordinary way.
(12) The combination of parts forming the whole apparatus to be used for the
purposes named herein, and constructed substantially as herein described, and
illustrated by drawings hereunto annexed.
27th October 1892.
ALFRED HORATIO NELSON.