Improvements in or connected with "Destructor” and other Furnaces.
Year: 1893

page_text: Date of Application, 1st Feb., 1893
Complete Specification Left, 1st Nov., 1893-Accepted, 2nd Deo., 1893
PROVISIONAL SPECIFICATION:
Improvements in or connected with "Destructor” and other
Furnaces.
We, JAMES JONES MELDRUM, and THOMAS FREDERICK MELDRUM, both 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 of or for "Destructors," and to other
kinds of furnaces wherein solid fuel is burned upon a grate, and to the combustion
of the fuel used therein.
In a furnace according to our invention there is employed a regenerator or
regenerators by which the primary air used to support combustion of the refuse or
fuel is heated prior to being passed through it, and a grate through a part or parts
of which water circulates or is circulated, such as a water-tube grate, or a grate
formed of water boxes, with tubes, conduits, or apertures therein to allow the
passage of air through them.
In some cases the regenerator or regenerators are of a continuous kind, wherein
the primary air is heated by being passed through conduits or passages heated
externally; whilst in other cases they are of an alternating type wherein chequer
work or other media is alternately heated up by the gases of combustion, or partly
used gases, and give out the heat so stored to the air by passing it over or through
the heated material.
In some cases the whole of the fire gases are passed through the regenerator,
while in others only a part is so used and such gases may pass direct into the
regenerator or regenerators. Or, there may be used in connection with the furnaco
and combined therewith a steam generator, or other article or apparatus or matter
to be heated, and a part of the heat of such fire gases taken out prior to its
application to the regenerative purposes.
The regeneration of heat may in some cases be effected in separate stages, as for
instance, the first regeneration or heating of the primary air may take place after
the fire gases have passed the steam generator or other thing to be heated, and a
part of the heat taken out; whilst the second regeneration or heating of the
primary air (already partially heated) may be effected by the whole or part of the
fire gases before reaching the steam generator or other thing to be heated.
The air used to support combustion of the fuel or refuse may be introduced into
or forced through the fuel by steam jot apparatus, namely, a steam jet blower or
blowers, or by steam jet exhauster or exhaustera. Suitable blowers for the purpose
may consist of a mixing tube with a coned inlet and tapered outlet; and it or they
may be arranged and mounted in a closed ashpit horizontally. When exhausters
are used a similar form of apparatus will serve. Or in lieu of these, other forms
and arrangements of parts may be employed.
In one form or construction of water tube grate, the tubes are preferably set
closely together; and to provide sufficient metal in the tube plates or headors to
which they are fixed, said plates or headers are provided with two rows of apertures
whilst one set of the tubes, or all the tubes, will be beut and fitted into said two
rows of apertures. This will provide for sufficient metal between the tube
apertures, and at the same time all the pipes between the bent parts within the
plates or headers may be level or even. Au equivalent construction by which the
same end is secured consists in employing tubes with ends which are fastened
to the tube plates or headers of less diameter than the body or intermediato
portion.
The invention may be applied to different kinds of " Destructors,” “Cremators,"

page_text: aud to different kinds of furnaces of other apparatus in whole or in part. It is also
not confined to the constructions of parts more particularly specified above, but can
be carried out by different forms or constructions of parts, or equivalents thereof
may be used; and it may be applied to the combustion of different kinds of
"refuse" and -fuels. ·
Dated this 31st day of January 1893.
CHEESBROUGH & ROYSTON, Fels. Chart. Inst. P.A.,
15, Water Street, Liverpool, Applicants' Patent Agents.
COMPLETE SPECIFICATION.
Improvements in or connected with "Destructor" and other
Furnaces.
We, JAMES JONES MELDRUM, and THOMAS FREDERICK MELDRUM, both 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 is to be
performed, to be particularly described and ascertained in and by the following
statement:-
This invention has reference to furnaces of or for Destructors, and to other kinds
of furnaces wherein solid fuel is burned upon a grate, and to the combustion of the
fuel used therein.
In a Destructor furnace according to this invention there is, amongst other
things, employed a regenerator or regenerators by which the primary air used to
support combustion of the refuse or fuel is heated prior to being passed through it;
a water tube grate through which or part of which water circulates or is circulated;
and certain improvements as to the working and utilization of the hoat of the
products of combustion of the material consumed therein.
3166
The invention may be applied to different kinds of "Destructors," Cremators,"
and to different kinds of furnaces or other apparatus in whole or in part. It is also
not strictly confined to the constructions of parts more particularly specified and
shewn in the drawings; and it may be applied to the combustion of different kinds
of refuse and fuels.
A Destructor or other furnace provided with improvements, or operating
according to this invention, is illustrated in the accompanying drawings, in which
Figure is a longitudinal sectional elevation, and Figure 2 is a cross section
thereof.
:
Figure 3 is an elevation shewing a detail of our improved furnace grate;
Figure 4 is a further view, i.e. side elevation, and Figure 6 is a plan, of said
grate; Figures 4+ 5 being a modification thereof. And
Figures 6 and 7, and 8 and 9 are respectively side elevation and plan of
modificatious.
Referring mainly in the first instance to Figures 1 and 2, a generally designates
the grate, cousisting of tubes, arranged at an inclination and closely together, and
fixed in the manner hereinafter described; 6 are "headers" in which the ends of
the tubes forming the grate are fixod. c is a tank adapted to aut as a circulating
tank to the grate, it being connected to the upper header & by pipes at the upper
part, and with the lower header b', at its lower part, by a pipe d'. The tank, tubes,
headers, and connecting pipes are filled with wator, and as it becomes heated by the
heat of combustion of material thereon, it passes upwards through the circulating
pipes d to the upper part of the tank c, and becoming somewhat cooled thorein flows
out at the lower part through the pipe d, by which it is carried to the lower
header b', and thence again into the grate pipes a, and so on, thus causing a
continuous circulation.
In some cases where steam generators are used in connection with destructor
furnaces, as in the arrangement shewn in Figures 1 and 2, the hot water froin the
grate may be used as feed water to the steain generators. Or, again in some cases

page_text: the steam generator may itself constitute a circulating tank to the grato, in which
case the headers would be directly connected with Baid generator.
The furnace proper or combustion space is designated, and it is enclosed by the
side wall f', and arch, which is provided with the apertures for the escape of
gaseous products of combustion. The front end of the furnace and destructor is
enclosed by a wall g, wherein, at the level of the grate, there is provided a door g¹
and aperture g³, covered normally by such door, for gaining access to the grate
bars, for raking the material down over the grate by hand, cleaning, removal of
matters, or otherwise; the door g' being hinged at the top, and normally kept
closed by a weighted arm connected therewith. Bolow this aperture is a close
fitting door h-say of the wedge fastening, "Meldrum," type-fitting on a plato k¹
secured to the front wall at this part; this door provides means of access to the
ashpit i, which lies directly below the grate, and is enclosed at its sides by the
walls and at its back end by the wall j. The opposite end of the furnace is
provided with a hoppar k, into which the mattor to be burned on the grate is
introduced, such matter being tipped or thrown into the hopper from a raised road
or platform I, supported upon columns l'.
9
Above the arch is a chamber m, the roof of which is formed by the upper
masonry platform n of the furnace; and out of this chamber lead to the left,
passages o, and to the right, passages o', which passages are carried down through
the wall in which they are built. At the bottom of the passages o and o¹ aro
flues of, out of which passages of lead to the "regenerator," as presently described.
Above the flue o', in that of the side walls in which the passages of exist, there
is provided another flue of, by which some of the gaseous products of combustion
are carried away to a steam generator and applied or utilized for the generation of
steam. These gases are led by way of a Hue p disposed transversely across the
furnace in the brick work p', the flue of leading direct into this flue. The proportion
of these gases which passes to the flues o' and regenerator, and to the flue p and
steam generatore, is controlled in this arrangement by a damper or valve p² shewn
in dotted lines; said valve being raised and lowered by a chain passing over the
pulleys p, and counterbalanced by a weight p'; thus accordingly as the exit of
the flue o, to the flue p, is more or less uncovered by the dampor p', so will more
or less gases pass to the steam generator, and be used for steam generation, and loss
or more used for regenerative purposes, namely for heating the primary air
employed in the combustion of the refuse.
"
The regenerator is disposed below the ground level-G L,-and consists of a
chamber filled with vertical tubes r', held at their ends in upper and lower tube
plates; a chambers above the upper tube plate and in communication with the
Hues o' through the aperturos o; a chamber beneath the lower tube plato; fresh
cold air supply flues ; and heated air discharge flues v. At, and in the front end
of, ench of the side flues u, are provided steam-jet blowers w (which are of the well
known "Meldrum" type, they being fixed by the head portions in the wall g (or
fixed to a moveable door, the frame of which is built in the wall g to facilitate
cleaning the flues) and having their diverging outlet portions disposed within the
flues u, and the inlet portions or heads being practically flush with the face of the
wall), whilst out of these flues us lead apertures u', forming communication
between us and the chamber r. The heated air outlet flues communicate with the
upper part of the chamber by the passages v', and at the back of the furnace they
lead into a vertical flue between the wall ; and tho brickwork p², and having its
upper end opening out into the ashpit i.
The chamber communicates with a main chimney flue x, by a flue ', having in
connection with it a damper, by which it is closed or opened, wholly or partially ;
whilst, in front of it is a door by which access is had to it, and the flues com-
municating with it. Similar doors (preferably of the "Meldrum" type above
referred to) to this are provided in the front walls g for gaining access to the
ohambors, and flues o, o' and r; of these a' are for access to the chambers an'l.
flues o, and to the fluos v, ..

page_text: In the operation of the Destructor furnace according to this invention-assuming
it to be in action,-the products of combustion of the matter being consumed upon
the grate a, pass from the grate chamber by way of the apertures into the
chamber m; and from thence they pass, partly to the right hand by way of the
passages o', to the steam generator y, through the flues of and p, and partly by way
of the passages o, to the flues o' and the chambers of the regenerator, whence they
pass through the tubes thereof into the chamber below, finally passing out by
the flue into the chimney flue_.. In passing through the tubes of the
chamber the hot gasos heat such tubes (theso transmitting such heat to the air
around them), leaving the regenerator chamber at a relatively low temperature.
The air, which is to be used for the combustion of the material on the grate a, and
to be heated previously to being so used by passing through the regenerator, is
introduced primarily from the atmosphere into the flues u by the steam-jet air
blowers, it being forced into same, and maintained at a pressure greater than
that of the atmosphere; that is to say, the air to be used in the combustion of the
material is artificially forced into and through the regenerator and through the
material to be burned. The air so introduced into the regenerator is distributed
over the bottom portion of the chamber r by the passages u', and then passes up
over the surface of the tubes, leaving the chamber r by the passages o' in a
heated state. It passes by these passages into the longitudinal flues v, which
convey it to the transverse end flue by which it is carried up and discharged into
the ashpit . The ashpit being a closed one, the air is forced through material on
the grate tubes, and being of a high temperature causes rapid and complete
combustion of the material thercon.
The portion of the products of combustion, takon and utilized for the generation
of steam, is taken from the flue p to the steam generator-a part of one being
shewn and designated y—in any suitable way, and employed as desired therein.
Referring now more particularly to the water cooled tubular grate according to
this invention, this part of our invention may be used with advantage for or in
connection with burning of different kinds of small and inferior fuels or combustible
matters. This improvement is illustrated separately in Figures 3 to 9, wherein four
methods of construction or arrangements are shewn; in all of which the construction
is such that the tubes are enabled to be placed, and are placed, closely together to
render the grate capable of supporting and having burnt upon it, the material or
fuels of small grade and poor quality. In the method of construction shewn in
Figures 3, 4, and 5, the alternate bars are, at one end, bent upwards, and the bent
end which fits in the tube plates of the headers, is swelled, and the hole in the
tube plate made of corresponding size. Thus the alternate apertures in the tube
plates of the headers will be small and large, so that half the tubes would be put
in position from one header, and half from the other. They, however, may be all
inserted from one end say through the front header of the grate. This in some
cases would be the preferred arrangement: it is shewn in Figures 4 and 5ª which
shew the two opposite ends of the tubes and headers of a. grate so arranged. In
this caso one half of the tubes would have their front beut ends swelled, and the
other half their front straight ends swelled (as shewn in the Figures) so as to
enable the tubes to. be passed through the tube plates of the headers and fixed
position.
in
In the modification shewn in Figures 6 and 7, all the tubes have one of their ends
of diminished diameter; whilst the alternate tubes at the opposite end are bent and
swelled, and plain, alternately.
In the modification shown in Figures 8 and 9, one end of all the tubes is
diminished in diameter, and half the tubes are passed into position through one
header in one direction, the other half being passed through the other header in the
opposite direction.
The grate a shewn in Figures 1 and 2, is, as will be seen, composed of tubes
forming an inclined bed for the material being consumed to rest upon, and side
tubes, carried up to a certain extent vertically on either side one above the other

page_text: which prevents the walls at the sides being rapidly destroyed, thus making a
channel shaped grate of water tubes placed very closely together, as described.
It will be seen by the drawings, that the part of the tubes near the lower header
in kept out of contact with the material to be burnt, by the plate g of the door-
way g; whilst the end portion of the tubes near the upper hendor, is shielded from
the action of the air passing through the grate, and little combustion goes ont at
that part. By these means, only those portions of the grate where the tubes are
close together, does combustion take place, and so the falling through of small
stuff is prevented at all points.
The main effect of this improvement, that is the improvement set forth with
raforence to Figures 3 to 9, is that, by the method of construction specified and
shown, the tubes can be arranged very closely to each other so that the spaces
between them would be as small as of an inch, or less if desired, whilst the
amount of inctal of the tube plates 6 between the tube ends is sufficiently great to
afford the required strength for boring, fitting, and fixing the tubes in them;
which obviously it would not be with ordinary tubes spaced of an inch, or
approximately this dimension, apart.
"By this construction of grate, and its application in connection with " Destructors,"
that is a grate with its bars or bearers artificially cooled by passing water through
them and set closely together so as to prevent unburnt matters from falling
through the employment of a regenerator (by which the air for burning the
material on the said grate is heated) is rendered practicable, as a high temperature
in the combustion of the material on the grate is obtained, and hot air can bo
passed through the grate without destroying the grate bars; and such combination
and arraugeinent constitutes a material advance in the utility and efficiency of
Destructor furnaces, or destructors.
In cases where the heat given out by the combustion and destruction of refuse
material such for instance as towns refuse-may be usefully employed for the
generation of steam, the improvement in the mode of working destructor furnaces,
consisting in dividing or taking a part of the products of combustion for regenerative
purposes to heat the primary air used for the combustion of the material on the
grate, and by taking the other part and applying it to the generation of steam,
effects a vory efficient and rapid destruction, and at the same time enables a
destructor to be rendered useful for providing motive power or a heating agent.
In cases where it is not desired to utilize the heat given off by the combustion of
the material burned in Destructor furnaces for the generation of steam, the special
arrangement in combination of grate, regenerator, air supply, etcetera, set forth with
reference to and shewn in Figures 1 and 2 of the drawings, may be employed with
advantage, without the parts or constructions by which a part of the gases are
conveyed away for steam generation. Also, in some cases, other means than steam
jet apparatus may be provided to deliver air into the flues u.
Having now particularly described and ascertained the nature of this inven-
tion and in what mauner the same is to be performed, we declare that what we
claim is :-
:-
1. The herein described improvement in "Destructor" or other furnace grates,
consisting of tubes secured in headers or chambers at each end, and having narrow
air spaces between them, the ends of the tubes, or some of them, being so formed
and arranged (substantially as described) as to enable said tubos to be set closely
together; for the purposes set forth.
2. The Destructor or other furnace grate, consisting of tubes set closely together
and having their onds formed as described, and headers in which said tube ends are
fixed, and through which water is caused to circulate, as set forth with reference to
and shown in the different figures of the drawings.
3. In a Destructor or equivalent or other "dry" furnace, a water tube grate,
comprising a plurality of tubes, and headers at each end of the grate in which said
tubes are fixed, and a circulating tank connected to both headers, substantially as

page_text: herein set forth, whereby a free circulation of water is maintained through the
tubes and parts, and the grate is prevented from becoming overheated or destroyed
by high temperatures.
4. The herein described improvement in Destructor furnaces or destructors,
comprising a grate having artificially cooled bearers onto which the material to be
burnt is introduced; and a regenerator consisting of a chamber through which a
plurality of tubes pass, disposed below the furnace, and whereto products of
combustion are brought by flues, and whereinto air is introduced and is heated by
being caused to flow over the surface of the tubes heated by the said products of
combustion, but on the opposite side thereof to that acted upon by the heating
gases, such air being then passed upwards directly into the ashpit and through the
grate; substantially as herein set forth.
5. The horoin described_improvement in the construction _and_working of
Destructor furnaces or destructors, consisting in effecting the division and
conveyance of the gases of combustion and the utilization and application of the
heat thereof, partly to the purposes of regeneration and boating of the primary air
used to effect the combustion of said material, and partly to the generation of steam
in steam generatora; substantially as herein described.
6. The Destructor furnace or destructor comprising an artificially cooled grate,
a tubular "continuous" regenerator, the tubes of which are heated by the products
of combustion of the material being burned, and steam jet blowers combined and
arranged in connection with air flues at the bottom of said generator, and delivering
air under pressure into said flues and regenerator, and forcing it through same, aud
into the ashpit which is closed-of the furnace and through the material on the
grate; all substantially as herein described and shewn in the drawings.
7. The Destructor furnace or destructor having parts arranged, constructed,
and adapted to operate, particularly as set forth with reference to and shown in the
drawing
mug
Dated this 31st day of October 1893.
CHEESBROUGH & ROYSTON, Fels. Chart. Inst. P.A.,
15, Water Street, Liverpool, Applicants' Patent Agents.