Improvements in Furnaces or Grates for the Consumption of Mineral Oils or the like as Fuel.
Year: 1898

page_text: COMPLETE SPECIFICATION.
Improvements in Furnaces or Grates for the Consumption of Mineral
Oils or the like as Fuel.
ALEXANDER MITCHELL, of 41, Devonshire Street, Portland Place, London, W.,
Gentleman, do hereby declare the nature of this invention and in what manner the
same is to be performed, to be particularly described and ascertained in and by the
following statement and accompanying drawings:-
This invention relates to the use or employment of mineral oils or the like as
fuel in the furnaces or grates of either land, marine or locomotive boilers or other
purposes for the generation of heat in manner hereafter described.
In the first instance, as in the case of land boilers, especially of the type or class
known as the Cornish or Lancashire boiler (although equally applicable or adapt-
able to other furnaces), a plate would be placed within the lower part of the boiler
flue and adjusted between the front portion of the fire bridge and that of the
furnace or grate surface, and upon the upper surface thereof a certain quantity of
asbestos fibre or other suitable material for the purpose would be placed and above
same and at a suitable distance therefrom, a perforated divisional plate would be
disposed so as to rest or bed at an agreed distance just apart that of the lower or
bottom plate and above or clear of the loose asbestos fibre or the like, and imme-
diately upon or above the entire surface of the upper perforated plate just referred
to I place blocks or balls composed of asbestos and fire clay or other suitable material
added to and formed therewith. The said blocks or balls would be placed in
successive layers over one another and preferably would have either a perforated
plate over and between each series or layers, or rods or bars of metal or other suitable
material may be interposed instead so as to keep the blocks or balls clear and apart.
An oil chamber or reservoir would be provided in the vicinity of the boiler
and so situated that the contents of same would be above the level of the lower
portion of the furnace grate. A series of pipes or tubes would be placed and
fitted within the said oil chamber or reservoir and their outer parts or ends led
toward and into the lower part of the furnace wherein the asbestos fibre or like
material is contained or held in position and the oil supply gradually fed thereto by
means of the said tubes in required quantities.
Suitable provision would be made to regulate the oil supply from the reservoir
to the furnace by means of either cocks, taps or valves and when required to
instantly cut off same.
I also propose to place and fit at the stoke hole end of the furnace a suitable
and convenient number of tubes closed at their inner portions and with numerous
holes or perforations formed around same in their length which are intended to
be placed or inserted between the layers or series of asbestos and fire clay balls or
blocks or the like and having their outer ends projecting from the front of the
boiler of cone like or other shape, open at their ends for the particular purpose of
enabling a free and ready admission of air into the furnace to aid and assist in
producing the necessary combustion desired.
As soon as it required to get up steam in a boiler, which can be readily effected

page_text: by simply turning on the tap, cock or valves as the case may be of the tubes or
pipes forming the connection from the oil reservoir to the furnace as before referred
to, the oil will then steadily flow into and among the asbestos fibre, and upon a light
being applied thereto through a small door or opening as would be suitably pro-
vided, the oil would then be speedily caused to ignite and steadily burn and be so
converted at same time into a vaporous form. The volume of flame by this means
would speedily become very intense and rapidly permeate through and around the
series of asbestos and fire clay blocks or balls or the like, rapidly converting them
into an intensely heated and incandescent state and at the same time readily taking
up and consuming all carbonaceous matters and gaseous or other products evolved
from the oil.
In addition to the natural inrush or air admission as would be secured by means
of the tubes placed as in manner previously referred to within the furnace, closed
at their inner ends and suitably perforated throughout but having the outer pro-
jecting ends of same open to the atmosphere;-I may in some cases provide a
revolving fan or other suitable means to create and give further draught or air
current either as forced or induced draught is needed, so that the atmospheric
current may be very rapidly brought into direct contact with the oil as fuel under
consumption.
The asbestos and fire clay balls or blocks, or of other highly incombustible material
such as may be best found in practice most suitable for the purpose, would by
preference be shaped somewhat similar to that of a hollow sphere or of like or
slightly irregular in form but in either case suitably perforated angularly through-
out.
In the case of marine boilers similar conditions would apply in the method of
fitting and working entirely dispensing with the use of fire bars and the ordinary
method of stoking.
In locomotive boilers this arrangement would likewise require but slight altera-
tion to fit and arrange and the tender of same could be easily converted into an oil
chamber or reservoir. The air admission to the furnace for securing the required
amount of combustion would in like manner be obtained by means of perforated
tubes placed within the furnace and having the inner ends of same closed and the
outer projecting ends open to the atmosphere with enlarged nozzles or openings
fitted thereto both at the front and back of the furnace or in other suitable manner.
Due provision would be made in all cases to keep the oil chamber or reservoir at
as low a temperature as possible which can be easily effected and so arranged as to
be provided with an outer chamber to contain water therein and a thick felting or
lagging of any suitable material as a non-conductor of heat around same.
The usual guage glasses would be provided so as to indicate the position or level
of the contents both of the oil fuel and that of the water surrounding same in the
outer case and if considered needful both pressure guages as well as relief or blow
off valves would be fitted should the surrounding temperature to the storage
reservoir in certain cases be far greater in excess to that of the average boiler room
or stoke hole.
The projecting tapered or open cone shaped nozzle portions in front of the stoke
hole or furnace for the inlet of air would be provided with a small pivotted disc, to
enable the air supply at any time to be either reduced or entirely cut off, this
together with the means provided for either regulating or shutting off the oil supply
would much more rapidly and with greater certainty than in drawing fires in the
usual manner.
In the accompanying drawings Figure 1 (Sheet 1) exhibits a longitudinal section
of a Lancashire or Cornish type of boiler wherein I have shewn my particular
system as applied thereto. And Figure 2 (Sheet 1) likewise shews my method as
applied to an ordinary type of marine multitubular boiler wherein in each case
the same letters of reference refer to like or corresponding parts.
A, is a divisional chamber or space formed within the lower part of the furnace
to receive asbestos fibre or other suitable material as may be preferred to be applied

page_text: in position therein. B, is a perforated divisional plate just above the asbestos fibre
or other material when in position. C, C, are blocks or balls of asbestos and fire
clay placed in layers or tiers just above the said perforated divisional plate B,
having also other perforated plates 1), D or rods or bars of metal or other suitable
material so as to keep the blocks or balls apart and in position. E, E are a series
of pipes or tubes suitably fitted in position from the oil chamber or feed reservoir F,
as shewn in Figure 2, and leading toward and into the lower part of the furnace
or asbestos chamber and contents A, and steadily supplies same with the liquid
mineral fuel or the like, the supply of which is capable of being regulated by means
of necessary cocks or valves G, G. H, H, are inlet or air admission pipes or tubes
closed at their ends and perforated throughout in their length by which means free
combustion is afforded. J is the water space or jacket surrounding the oil
reservoir F, K, is also a coating of suitable non-conducting material to aid in keep-
ing the oil reservoir F at a low temperature. L is a guage to indicate the level
of the oil contents.
In Sheet 2, Figure 3 shews my system or method as applied to a locomotive boiler
and tender and the same letters of reference and method of working as before
referred as at Figures 1, and 2 equally applies.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I claim
is:-
:―
I. In the particular manner and method in combination for the consumption or
burning of mineral oils or the like as fuel in furnaces of various types in manner
substantially as herein described and illustrated.
Dated this 22nd day of March 1898.
ALEXANDER MITCHELL.