Improvements in or connected with Steam Generator and other Furnaces.
Year: 1893

page_text: Date of Application, 9th Sept., 1893
Complete Specification Left, 6th July, 1894-Accepted, 18th Aug., 1894
PROVISIONAL SPECIFICATION.
Improvements in or connected with Steam Generator and other
Furnaces.
We, JAMES JONES MELDRUM, and THOMAS FREDERICK MELDRUM, of
Atlantic Works, City Road, Manchester, in the County of Lancaster, Engineers,
do hereby declare the nature of this invention to be as follows:-
:-
This invention has reference to furnaces, but more particularly steam generator
furnaces of locomotive and other steam generators having little or no natural
draught; that is to say furnaces having little or no height of chimney. And it
also has reference to the construction of grates wherein artificial draught is
employed.
As regards the first part of our invention, we work furnaces of this kind with an
artificial draught created by jet blowers, and in such a manner that the firing or
stoking can be carried on with greater facility and convenience by the stoker,
or those employed in front of the furnaces, than heretofore; as for instance, we
work the artificial draught in such a manner that the flame or fire gases are
prevented from being forced out through the furnace door when opened into the
space in front thereof, and burning the attendant or attendants, or that the stoking
is not rendered difficult or inconvenient.
Under this invention this is effected by employing exhausting jet apparatus in
the outlet of the steam generator, and a jet blower or blowers blowing into the
ashpit; the latter being preferably within the ashpit, that is, lying wholly or
principally therein; whilst the supply of steam to both blowing and exhausting jet
apparatus is controlled by a common controlling device, so that it may be put on or
cut off at once to both sets of apparatus.
In one arrangement, this may be done by employing the valve or valvular device
or cock common to both apparatus.
The improvement connected with furnaces employing an artificial draught,
consists in employing a tipping grate or a portion of a grate combined or arranged
in conjunction with a jet blower or blowers lying wholly or mainly within the ashpit
and blowing or forcing the air into same.
It is to be stated that the improvements under this invention may be differently
arranged and constructed or modified without necessarily departing from its
legitimate scope.
Dated this 8th day of September 1893.
COMPLETE SPECIFICATION.
Improvements in or connected with Steam Generator and other
Furnaces.
We, JAMES JONES MELDRUM, and THOMAS FREDERICK MELDRUM, of
Atlantic Works, City Road, Manchester, in the County of Lancaster, Engineers,
do hereby declare the nature of this invention and in what manner the same
[Price 8d.]

page_text: :
is to be performed, to be particularly described and ascertained in and by the
following statement :-
"
This invention has reference to furnaces, more particularly furnaces of locomotive
and other steam generators having little or no natural draught, that is to say,
furnaces having little or no height of chimney; and secondly, it has reference to
the construction of grates of furnaces wherein artificial draught is employed.
The invention being, as stated, particularly applicable to locomotive steam
generators, the improvements thereunder will be described in connection with a
locomotive type of steam generator.
In these drawings, Figure 1 is a longitudinal elevation partly in section
illustrating our arrangement or means for carrying on firing so that the flame and
fire gases are prevented from being forced out, or having a tendency to pass out
through the furnace door when opened, and Figure 2 is a back end view of the
.arrangement of parts of and connected with the steam jet blowers and ashpit.
Figure 1 also shows the tipping grate according to this invention.
Figure 3 is a side elevation. and Figure 4 a plan illustrating the improved tipping
grate under this invention.
Referring more particularly to Figures 1 and 2, a are steam jet blowers by which
the air for combustion of the fuel on the grate is introduced into and maintained at
a pressure above the atmosphere in the ashpit of the locomotive steam generator,
the blowers being preferably of the form shewn, that is of the "Meldrum type,"
with a coned inlet, cylindrical mixing tube, and diverging outlet, and having the
portions forming the body lying substantially wholly within the ashpit, the blowers
being provided, one on each side thereof, and connected by their heads to the back
end plate c of the ashpit. d is the nozzle or steam jet device by which steam in a
jet is discharged up the funnel e of the steam generator, and whereby an exhaustion
in the snoke box f is created, and the pressure within it is maintained below that.
of the pressure of the atmosphere, and the pressure in the furnace above the fuel,
that is the combustion chamber, is maintained at or slightly under that of the
atmosphere. 9 are the steam pipes for conveying the steam from the steam
generator to the blowers a and exhausting steam nozzle d, and h is the cock or
valve common to said pipes by which the steam both to the blowers, and the
exhauster is supplied, regulated, or cut off at once, thereby keeping the relative
degrees of force of action of the blowing and exhaust devices constant at all times,
and so insuring the degree of plus pressure in the ashpit, and minus pressure in the
smoke box, being that necessary at all times to cause the pressure in the combustion
chamber to be that desired, and to enable the firing to be carried on so that the:
flame and fire gases are not forced out through the furnace door when opened, and
the firing and stoking to be conducted without difficulty or inconvenience. The
proper proportion of supply of steam to the blowers a and the exhausters d being
.found, is maintained by regulating the outlet of the nozzle or jet devices d by a
regulating spindle d'; or, it may be done by providing a regulating cock or valve
(shewn in dotted lines and marked *) or the like on the pipe g between the steam
pipe supplying the exbauster d, or a like cock or valve (shewn in dotted lines
and marked d) on the pipe supplying steam to the blowers a, or on both.
It may be here stated that as regards the particular form and arrangement of
parts described, by which the effect specified is obtained, the invention is not
necessarily restricted to those specifically shewn and specified, but at the same
time such arrangement and forms or parts are those which we at present prefer
to employ.
In the case of the application of the invention of the combined exhaust and
plus pressure forced draught as a mode of carrying on the combustion of fuel being
employed in locomotives, the exhaust from the engine cylinder or cylinders in some
cases, may be discharged direct from the engine into the air; or it may be used in
combination with the exhausting jet, thereby providing a supplementary means of
creating a rarefaction when the engine is running; or again, such steam may be
merely discharged from the cylinders into the smoke box. In Figure 1 the exhaust

page_text: shewn is supposed to be discharged into the open air through a pipe separate from
the funnel and we prefer not to use the exhaust steam for producing a rarefaction;
but where it is so used, the exhausting live steam jet should either be in the
centre of the jet of exhaust steam, or be arranged in the form of a ring of jets
outside it.
Access is had to the ashpit by doors ij, the door being hinged on the spindle-
and making an air tight joint with the ashpit end plate c on an inclined face, whilst
the door rests, when closed, on a seat in the opposite end plate k of the ashpit,.
making an air tight joint therewith, it being hinged on the bar j'. These doors are
in the case of the application of the invention to a locomotive, lifted or opened and
closed from the foot plate of the locomotive through suitable levers in the..
ordinary way.
The blowers and the cleaning door or doors are placed at that end of the ashpit™
which under different circumstances may render one or the other the more
convenient, and in most cases, a door at each end of the ashpit is provided, as.
shewn in Figure 1.
By the above described mode of and means for conducting combustion of fuel,
one of the advantages amongst others to be derived from the use of the invention
is that, in the application to locomotive steam generators, anthracite coal free from.
sulphur can be used, and effectively and efficiently burned; and in such a case-
practically no smoke and sulphurous fumes will be made or thrown off from the
engine, which on lines where a large proportion of the system is tunnel, is a feature.
of considerable importance.
The tipping grate arrangement above referred to which is used with great.
advantage in the case of or under the conditions last specified-but which may be:
used in any case is illustrated with reference to Figures 3 and 4 of the drawings..
These figures shew this improvement as applied to a locomotive type of boiler
furnace. In this arrangement, part only of the grate is adapted to tip, namely, the
part designated m, while the rest marked n consists of stationary bars. The tipping
portion m is made up of bars having saddle bearings o towards one end of same,..
resting on a fixed journal or bar p common to all of the bars, whilst the opposite end
of said bars forming the tipping portion are connected together by a tie bar q, a
distance piece being provided at each end, and at any parts where deemed necessary
to keep the bars at the right spacing or distance apart. The tipping bars are
operated by a lever supported upon a fulcrum bar s, and a T headed part t having
a bar t¹ at each side at right angles to it, which bears normally on the underside of
the bars. When the handle of this lever is raised, the bars, or the ends of the-
bars, supported by the end t of the lever fall, and the part on the other side at the
other end rise into the position shewn in dotted lines, the movement taking place on
and about the supporting shaft p. When the grate portion m is tipped in this.
manner, the whole grate can be cleaned, that is ridded of clinker, etcetera, through
the space made by the falling of the tipping portion m. To bring the grate back
to its normal state, the lever is depressed into the position shewn in full lines,.
thereby bringing the bars to their normal working position, and it is held there by
a pin, as, or other suitable means.
↑
As regards the tipping portion of the grate, this should be placed conveniently
in relation to the ashpit door or doors to enable the ashes and matters discharged
through the opening afforded by it, to be readily cleared or removed from the
asbpit.
The improvement described with reference to grates of steam generators, is
particularly applicable and useful in connection with locomotive types and vertical
types of steam generators wherein the ashpit is closed and forced draught is used,
and the doorway for stoking the furnace is through a water space, and where access.
to the grate through such doorway for cleaning purposes is difficult.
In some cases, as the exhausting means connected with the chimney, a multiple
arrangement of steam nozzles as the usual ring of nozzles is used instead of the
single arrangement set forth with reference to the drawings.

page_text: Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
-
1. A steam generator or other furnace comprising steam jet blowers by which
air is forced under pressure into a closed ashpit of the furnace, and a steam jet
exhausting device by which the gases from the furnace are forced up the chimney
or outlet, and the pressure in the furnace above the fuel is regulated, said steam jet
blowing and exhausting devices having their supply regulated by means substan-
tially as described, whereby pressures under and above the fuel are such as create
a forced draught and combustion, and at the same time prevent flame or fire gases
passing out of the furnace door; operating substantially as and for the purposes
set forth.
2. In or connected with a steam generator or other furnace, the combination with
a steam generator of a closed ashpit, steam jet blowers a with bodies comprising a
mixing part and diverging outlet tube lying horizontally in the ashpit thereof,
fastened by their heads to end plate, the whole blower being practically within said
ashpit; a door or doors for gaining access to the ashpit; an exhausting nozzle
connected with the chimney operated as specified; and a common system or
arrangement of pipes and steam regulating means by which steam from the
generator is supplied and regulated to both the blowing and exhausting devices;
arranged, combined, and operating substantially as set forth with reference to and
as shewn in Figures 1 and 2 of the drawings.
3. In or connected with a locomotive type or other water cased steam generator
or other furnace, the improvement consisting of a closed ashpit, steam jet blowers,
by which air is supplied under pressure into said ashpit, and a grate having a
tipping portion: substantially as described.
4. In or connected with steam generator or other furnaces, a grate composed of
fixed fire-bars or bearers, n, and a portion m, adapted to be tipped, arranged and
adapted to be operated as set forth with reference to and as shewn in Figures 3 and 4
of the drawings.
Dated thi Thind dor of Inl 1804
Thi
day of Imly 1204
CHEESBROUGH & ROYSTON, Fels. Chart. Inst. P.A.,
15, Water Street, Liverpool, Applicants' Patent Agents.