Improvements in or connected with the Destruction or Combustion of Towns' and other analogous Refuse, and Furnaces therefor, and other analogous Furnaces.
Year: 1896

page_text: Date of Application, 2nd July, 1896
Complete Specification Left, 3rd May, 1897-Accepted, 12th June, 1807
Improvements in or connected with the Destruction or Combustion
of Towns' and other analogous Refuse, and Furnaces therefor,
and other analogous Furnaces.
We, JAMES JONES MELDRUM, THOMAS FREDERICK MELDRUM, and JOHN
WESLEY MELDRUM, all 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, primarily, to the destruction or combustion of
towns' refuse, and like material, and has, mainly for its object to render the
destruction or combustion of such material complete and efficient, as well as to
utilize to the utmost practicable extent the heat generated, and by an apparatus
or plant of simple and compact form, and one that can be worked or used with
ease.
According to this invention, the end sort to be accomplished is effected by burning
the material on a grate or grates in a brick chambered furnace having divided or
separate ashpits or chambers below, into which the air for its combustion is
introduced by air forcing apparatus, under a pressure greater than that of the
atmosphere, by feeding the material onto the different parts of the grate or grates
above said separate air chambers or ashpits, at different times, i.e. by a periodic
method of supply, so that one. part of the furnace is in a full state of combustion
when the other has been replenished with fresh material, and by causing the flames
or hot gases from one to mix with the fresh gases from another; and by heating
the air so delivered into said air chambers or ashpits, by passing it over the outside
of tubes heated, by passing the waste gases discharged from the furnace through
them; in some cases, the waste gases being first passed through or under, and used
in or under a steam generator, for the generation of steam, and then through the
air heating tubes of the air heater, and finally to the chimney or outlet.
The brick chambered furnace is preferably arranged with one practically
continuous grate, the underside of the fire-box being divided into two or more
compartments or aslipits supplied with air under pressure, and so arranged that the
air supply may be shut off from any one or more compartments as may be desired.
Over each compartment or ashpit is fixed a convenient door for cleaning the fire or
charging the material to be burnt. In some cases two sets of doors may-be
provided, one set at the back for charging the refuse through and a second set on
In other cases the
the opposite side through which to clinker or clear the fires.
material to be burned may be charged through hoppers or shoots over the
furnace.
The air heating apparatus is placed as near the ashpits as convenient and consists
of a ebamber, and preferably vertically disposed tubes extended between and fixed
by their ends in upper and lower tube plates. We prefer to pass the heated gases
through these tubes, the air passing laterally through said chamber, and over the
outside surfaces of the tubes, and conveyed in its heated state to the ashpit by a
flue or conduit.
We prefer to draw the air ibrough the air heater and force it into the ashpits at
a pressure above the atmosphere by means of steam jet blowers connected with or

page_text: lying within said ashpits. We do not however confine ourselves to this mode
of forced draught and in some cases may use a fan forcing air through the air
beater or regenerator, and thence into the several ashpits.
In one special combination and arrangement of apparatus under this invention,
the furnace portion consists of a number of grates, ashpits, and doors and sets of
blowers, say three or more of the kind above referred to; that is, these different
parts of the furnaces are arranged side by side, with their cleaning and feeding
doors in front, and so arranged that the gases flow in a direction parallel with the
front of the furnace, those from the one or others of the grates beyond or in front
of that at the outlet end, passing over this grate, or this and others as the case may
be, or otherwise suitably mixing together. The hot air conduit is conveniently
arranged below the level of the floor; and within the ashpit closing plate at the
front of the furnace, there are conduits or inner chambers to which air is supplied
from the hot air conduit; and in the back plate of these air conduits the heads of
the steam jet blowers are fastened, their bodies extending horizontally into the
ashpit. In one arrangement, a blower is arranged on either side of the ashpit; and
between them in the front plate is an air tight door-say of the Meldrum type-by
which access is had to the ashpit for clearing it of ashes, or for other purpose.
The air is thus drawn from the main air conduit (and through the air heater as
described) up into the conduits or chambers to which the heads of the blowers are
fastened, and thence, forced by the steam jets into the ashpits under the bars. At
one end of the furnace the air heater is arranged, having its front walls continuous
with the front wall of the furnace, and being practically a continuation thereof.
This air heater consists of tubes and tube plates arranged as described, and has the
conduit for the heating gases at the upper part, whilst the chamber for the outlet
is below, such outlet being provided with a damper for regulation. The air enters
the air heater at the end furthest from the furnace, and passes through it, and then
down into the hot air flue specified.
In some cases, at the back of the furnace and air heater, a horizontal steam
generator of any known suitable kind is arranged, the inlet for the hot gases to
which is disposed at the same end of the plant, as the common outlet for the hot
gases of combustion from the furnaces, the connection between these two being by
a transverse chamber at the end of the plant. Then, at the opposite end of the
plant, the gases leaving the steam generator pass by way of another transverse flue
to the space or chamber above the air heating tubes; while another passage
provided with a damper passes from it to the chimney flue or outlet, by which, in
conjunction with the damper on. the air heater outlet flue, the flow. of waste hot
gases can either be passed wholly through the air heater, or wholly direct to the
chimney or outlet flue, without passing through the air heater; or partially
through the chimney flue, and partially through the air-heater.
In some cases different parts of the grate over the different ashpits are of a
tilting kind whereby one or more sets of bars over each asbpit are made to work
on a hinge or pivot, so that the clinker or incombustible residue may be tipped into
the ashpit, instead of being raked out through the cleaning door into barrows as is
usually the case. By this plan, not only is the most arduous part of the fireman's
work very much reduced, but the heat of the clinkers is also utilized to still further
raise the temperature of the air for combustion. After the clinker has sufficiently
cooled in the ashpit it may be dumped into trollies running in a subway beneath
the ashpite or may be otherwise dealt with.
Although this invention has been described as applied mainly to the destruction
or combustion of towns' refuse and like materials, it may nevertheless be also used
in part or in whole as an apparatus or furnace in which the material burnt is coal,
coke, or other such material.
D
ليمه
CHEESBROUGH & ROYSTON,
15 Water Street, Liverpool, Applicants' Patent Agents.

page_text: Improvements in or connected with the Destruction or Combustion
of Towns' and other analogous Refuse, and Furnaces therefor,
and other analogous Furnaces.
We, JAMES JONES MELDRUM, THOMAS FREDERICK MELDRUM, and JOHN
WESLEY MELDRUM, all 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, primarily, to the destruction or combustion of
town's refuse, and like material, and has mainly for its object to render the
destruction or combustion of such material complete and efficient, as well as to
utilize to the utmost practicable extent the heat generated, and by an apparatus or
plant of simple and compact form, and one that can be worked or used with.
ease.
According to this invention, the end sought to be accomplished is effected by,
burning the material on a grate or grates in a brick chambered furnace having
divided or separate ashpits or chambers below, into which the air for its combustion
is introduced by air forcing apparatus, under a pressure greater than that of the
atmosphere, by feeding the material onto the different parts of the grate or grates.
above said separate air chambers or ashpits, at different times, i.e. by a periodic
method of supply, so that one part of the furnace is in a full state of combustion
when the other has been replenished with fresh material, and by causing the flames.
or hot gases from one to mix with the fresh gases from another; and by heating
the air so delivered into said air chambers or ashpits, by passing it over the outside
of tubes heated, by passing the waste gases discharged from the furnace through
them; in some cases, the waste gases being first passed through or under, and used
in or under a steam generator, for the generation of steam, and then through the
air heating tubes of the air heater, and finally to the chimney outlet.
The brick chambered furnace is preferably arranged with one, practically
continuous grate, the underside of the fire-box being divided into two or more
compartments or ashpits supplied with air under pressure, and so arranged that the
air supply may be shut off from any one or more compartments as may be desired.
Over each compartment or ashpit is fixed a convenient door for cleaning the fire or
charging the material to be burnt. In some cases, two sets of doors may be
provided, one set at the back for charging the refuse through, and a second set op
the opposite side through which to clinker or clear the fires. In other cases the
material, to be burned may be charged through hoppers or shoots over the
furnace.
The air heating apparatus is placed as near the ashpits as convenient and consists
of a chamber, and preferably vertically disposed tubes extended between and fixed
by their ends in upper and lower tube plates. We prefer to pass the heated gases
through these tubes, the air passing laterally through said chamber, and over the
outside surfaces of the tubes, and conveyed in its heated state to the ashpit by a
Hue or couduit.
We prefer to draw the air through the air heater and force it into the ashpits at
a pressure above the atmosphere by means of steam jet blowers connected with or
lying within said ashpits. We do not however confine ourselves to this mode of
forced draught and in some cases may use a fan forcing air through the air heater
or regenerator, and thence into the several ashpits.
In one special combination and arrangement of apparatus under this invention,
1

page_text: the furnace portion consists of a number of grates, ashpits, and doors and sets of
blowers, say three or more of the kind above referred to; that is, these different.
parts of the furnace are arranged side by side, with their cleaning and feeding doors
in front, and so arranged that the gases flow in a direction parallel with the front
of the furnace, those from the one or others of the grates beyond or in front of that
at the outlet end, passing over this grate, or this and others as the case may be, or
otherwise suitably mixing together. The hot air conduit is conveniently arranged
below the level of the floor, and within the ashpit closing plate at the front of the
furnace, there are conduits or inner chambers to which air is supplied from the hot
air conduit; and in the back plate of these air conduits the heads of the steam jet
blowers are fastened, their bodies extending horizontally into the ashpit. In one
arrangement, a blower is arranged on either side of the ashpit; and between them
and the front plate is an air-tight door-say of the Meldrum type-by which access
is had to the ashpit for clearing it of ashes, or for other purpose. The air is thus
drawn from the main air conduit (and through the air heater as described) up into
the conduits or chambers to which the heads of the blowers are fastened, and thence,
forced by the stean jets into the ashpits under the bars. At one end of the furnace
the air heater is arranged, having its front walls continuous with the front wall
of the furnace, and being practically a continuation thereof. This air heater
consists of tubes and tube plates arranged as described, and has the conduit for the
heating gases at the upper part, whilst the chamber for the outlet is below, such
outlet being provided with a damper for regulation. The air enters the air heater
at the end furthest from the furnace, and passes through it, and then down into the
hot air flue specified.
In some cases, at the back of the furnace and air heater, a horizontal steam
generator of any known suitable kind is arranged, the inlet for the hot gases to
which is disposed at the same end of the plant, as the common outlet for the hot
gases of combustion from the furnaces, the connection between these two being by
a transverse chamber at the end of the plant. Then, at the opposite end of the
plant, the gases leaving the steam generator pass by way of another transverse flue
to the space or chamber above the air heating tubes; while another passage
provided with a damper passes from it to the chimney flue or outlet, by which, in
conjunction with the damper on the air heater outlet flue, the flow of waste hot
gases can either be passed wholly through the air heater, or wholly direct to the
chimney or outlet flue, without passing through the air heater; or partially through
the chimney flue, and partially through the air-heater.
In some cases, different parts of the grate over the different ashpits are of a
tilting kind, whereby one or more sets of bars over each ashpit are made to work
on a hinge or pivot, so that the clinker or incombustible residue may be tipped into
the ashpit, instead of being raked out through the cleaning door into barrows, as is
usually the case. By this plan, not only is the most arduous part of the fireman's
work very much reduced, but the heat of the cliukers is also utilized to still further
raise the temperature of the air for combustion. After the clinker has sufficiently
cooled in the ashpit it may be dumped into trollies running in a subway beneath
the ashpits or may be otherwise dealt with.
Although this invention has been described as applied mainly to the destruction
or combustion of towns! refuse and like materials, it may nevertheless be also used
in part or in whole as an apparatus or furnace in which the material burnt is coal,
coke, or other such material.
Two modifications of the apparatus, the nature of which is above described,
are given in the accompanying drawings. In these, Figures 1 to 3 shew one
modification, having a duplex arrangement of apparatus or plant. In these,
Figure 1 is an elevation partly in section taken through the line A A Figure 2;
Figure 2 is a plan partly in section taken at the line B B Figure 1; and Figure 3
is a cross section taken at the line C C Figure 1.
The other modification is shewn in Figures 4 to 7; in which Figure 4 is an
elevation partly in section taken at the line E E Figure 5; Figure 5 is a plan in

page_text: section taken at the line F. F. Figure 4; Figure 6 is a cross section taken at the
line GG Figure 4; and Figure 7 is a longitudinal section taken at the line H. H.
Figure 5.
Referring in the first instance to Figures 1 to 3 of the drawings, the combustion
space or furnace proper is designated a, and comprises front and back walls a', and
an arched roof a of firebrick brickwork, one end being closed by a wall a³, the
other end being open above the bridge a. b is the bed on which the material is
burned, and consists substantially of fire bars, the direction of length of which is
from the front to the back walls a'; and b' is a brickwork dead plate or shelf, at the
back, onto which the refuse or material to be burnt is charged prior to being
placed and burnt upon the bed b. is a hopper or spout through which the
material is fed to the furnaces, the entrance to which is controlled by a door x.
care doorways in the front wall a, through which the material is raked from the
shelf bl, and by which the bed b is cleaned, and clinker, etcetera, is removed; the
doorways c being covered and uncovered by vertically moving doors d.
the chambers or ashpits below the firebed b, such chambers being separated
from each other by division walls f, and ridge vertical plates fi extending from
the top of these walls to between two of the bars of the bed. These chambers e
are enclosed at the back and bottom by brickwork; and at the front, by metal
enclosing walls g, which have air tight fitting doors g' at the lower part, covering
an opening therein for obtaining access to the ashpits for clearing them of ashes,
and other purposes. The ashpits e, as will be seen, lie side by side, while the fire
bed b extends across them and is common to them all.
e are
A part of the bed of each ashpit may be of the tilting kind, the object being to
utilize and carry back to the fires the heat of the large quantity of clinker that
is discharged from the grates of refuse destructors. The type of tilting grate
suitable for this purpose is that set forth in a former Patent Specification No. 16968.
of 1893.
The chamberse are supplied with air by steam jet blowers h, secured at their
heads to the back of a metal conduit i, their bedies lying horizontally, and wholly
within the ashpits e. The mouths of these blowers open out into the conduits i,
and are there provided with a central steam nozzle in any of the well known ways.
jare the steam pipes conveying .the motor or air forcing steam to the blowers.
The air introduced into the ashpits e is first moved through the air heating or
regenerative heating apparatus hereafter described, and then delivered into such
ashpits, and maintained therein under a pressure above that of the atmosphere, by
the steam jet blowers ; it being conveyed to the conduits i through and from
a main hot air trunk k, having branch conduits & connecting it at different points with
the conduits i. ' are caps on the ashpit front g by which access is had to the blower
inlets when they are removed.
The material which, say, is ordinary towns' refuse,. is charged into the supply
shoots from the inclined platform y, outo which it is tipped from the floor or
surface z.
As is seen by the drawing, the apparatus shewn in these figures is a duplex
arrangement, end for end. At the inner end of each of the furnaces, and forming
substantially a continuation of the furnace front, the air heater is disposed. This
comprises substantially a chamber enclosed at the top and bottom by plates m m³,
and at the back and frout by walls ; vertical tubes n extending between, and
being secured at their ends in the plates m m¹; an upper chamber or space o
between the plate m and the roof o'; and chamber p below the plate m'. The air
to the chamber is introduced through a passage 12, communicating with the
atmosphere at the top of the destructor; and it is conducted away from same, and
carried into the conduit k, by a conduit 13. The waste hot gases enter the
chamber o by a passage of from the waste gas flue of the steam generator,
hereinafter described, and pass down from the chamber o through the tubes n to
the chamber p, into the outlet conduit q for the cool gases.
At the back of the furnaces, and air heater, a steam generators of the Lancashire

page_text: type is disposed, into the internal flues s' of which, the gases from the furnaces a
are led by the end flue r; whilst at the opposite end of the plant, a flue is
provided which conducts the hot waste gases from the flues of the generator s by
the passage o² to the air heater chamber.o. This steam generator is, set in brick-
work in the usual way with. the .usual flues; and the end conduit r. is also, of
brickwork, as shewn.
u is the cool gas discharge flue, with,,which the gas, conduits are connected, and
by which the gases are led to the chimney or other outlet.. The conduits have.
upon them, dampers q', by the regulation of which the opening of the passages 7 is
regulated.
The operation of the plant or apparatus is as follows:-The material to be burned is
charged into the furnace through the hoppers or shoots a, the different fires upon the
bed b, above the different ashpits e, being worked in cyclical order; that is, in the case,
shewn, with three fires, they may be fed or charged at even intervals, in order, one every
20 minutes, so that one fire is charged with fresh, material once in the hour. By this
means, the material on one or more of the parts of the bed above one or more of the
ashpits e will be in a full state of combustion at all times; and therefore, when
fresh material is raked from the "dead-plate" onto that part of the fire which
has been burning the longest, the fresh gases given off will, on account of the,
furnace or space a being common to all the fires, and the gases from all having to
pass the same way, become mixed with the hot gases or flames from another or
other parts, and so complete combustion of all noxious and offensive gases is
promoted, and prevention of formation of smoke accomplished.
The gases from the fires all pass together over the bridge at into the end fluer,
and thence into the fluess of the generators, in which they give. up a greater
portion of their heat to the water therein; and the steam thereby made is used as
motor steam for the jet blowers h,(the surplus, being used for any other purpose),
it being carried to the blowers by the pipes j. From the flues of the steam
generator, the, gases pass into the chamber o, of the heater; and thence down
through the tubes n thereof into the lower chamber.p; whence they pass by the
conduit.q into..the outlet flue u. In passing through the tubes.n, these gases part
with some of their heat to them, and the heat so transmitted, is taken from them
by the air which is being moved over them externally by the steam jet, blowers h.
The air enters the chamber through the passage, and is discharged at the
opposite side through the conduit 13 down into the hot air flue k. From this flue,
as stated, the hot air passes by way of the branch conduits k', and vertical metal
trunks i in the chambers e, to the inlets of the blowers h; from whence it is forced
by the steam jet into the chambers.e, and maintained there at a pressure above that
of the atmosphere.
In the case of tilting grates being used in the furnace, the air, when delivered
into the ashpits e, is further heated by the clinkers that are discharged
into them by the tilting parts of the fire bed. As the quantity of clinker
discharged from the fires for burning refuse material of the kind referred to, is
comparatively very large, the amount of heat that is conserved and returned to
the fires through heating the air used to burn such material by them, is considerable.;
with the result that its combustion is more quickly and completely effected. The
operations.connected with, this feature of the invention, are, that when the fire is
cleaned and the clinker discharged through the aperture made in the bed by tilting
a part thereof, such clinker is retained in the ashpit until just prior to the next or
other cleaning operation, and the air entering the ashpits takes up the heat from
them.
1
The hot air under pressure, by its combined force and temperature, keeps the
combustion of the material ou, the firebars b in a very,active state; and these,
together with the arrangement of fires, and, their mode of action and treatment,
causes a ready burning and destruction of the material as it is charged onto it, and
effect a complete annihilation of all noxious or offensive.vapours or gases given off
from the material...
'

page_text: In the modification shewn in Figures 4 to 7, the apparatus is adapted to be feil.
with material in a modified manner to that shewn in Figures 1 to 3, and the,
arrangement and disposition of the air heater or regenerator are modified, there are;
also other modifications which will be included in the description hereafter given:
of this arrangement.
Referring to Figures 4 to 7, the material in this case to be burnt on the bed b is.
introduced through the doorways c which are normally covered by the vertically.
sliding doors d, and through these doorways also the fire is raked clean and
attended to. It will be seen, in this case, there are five separate ashpits instead of,
three as in the other arrangement'; and in this case, instead of the gases having
access, or being able to pass over the back portion of the furnace and walls, or
over the bed proper, namely, the dead plate in. Figures 1 to 3, they have all to
pass over the fuel directly upon and above the bed b, leaving the furnace chamber a
by the passage above the bridge a', and enter the end flue.r.
The gases pass to the steam generator s at the back of the furnace as in the:
former arrangement, and thence to the air heater.
.;
.
The air heater in this arrangement, is disposed directly. beyond the end of the
steam generator, and not at the end of the furnace a, which, in the case shewn, is
at this part provided with a doorway t covered normally. with a sliding door t¹.
The gases leaving the steam generator pass by way of the conduit or flue o to the,
chamber o, and then on through the tubes n into the chamber p and gas flue q, and.
away to the chimney or other outlet. The cold air enters the air heater through
the conduit 12; and passing in a horizontal direction over the surfaces of the.
heating tubes n in the chamber 1, leaves by the downtake hot air conduit ³, which
at the lower part opens out into a horizontal passage connected directly with the
hot air supply conduit k, beneath the ashpits e. Erom this conduit the hot air,
passes up by the branches and vertical metal conduits i to the steam jet blowers h,
as in the former arrangement.
In this arrangement there is also provided in connection with the steam generator
a flue v, having a regulating damper viponit. By the regulation of this damper,
and the damper g' in the air heater discharge conduit, the quantity of gases which
can be made to pass through the air heater, and directly to the chimney or other
outlet, can be regulated and controlled as desired; or, by opening one and closing
the other completely, the whole of the gases from the flue t can be passed either
through the air heater, or, be by-passed therefrom, and made to flow direct to the
chimney or other outlet through the passage v.
The material to be burned is contained in a hopper 1 in front of the furnace,
and is preferably of such a size as will hold say a day's supply. It is filled direct
from the carts, which back against the stop block 2. The bottom of the hopper
at 3 is preferably raised above the floor line for the convenience of the fireman
who shovels the refuse directly from the bottom 3 into the furnace through the
doorways c. The hopper openings 4 correspond in number with the fire-doors d.
In some cases, as those where the material to be burned is very poor in
combustible properties and condition, and the gases of combustion contain relatively
a small quantity of heat, the steam generator will not be employed, and the gases
will pass direct from the furnace to the air heater; the use of which, under such
conditions, will be essential to effective combustion and destruction.
In another modification, the gases of combustion of the fuel on the bed-b, may
be conveyed backwards to a flue behind or below the bed, instead of sideways as
shewn in the drawings.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The improvement herein set forth in or in connection with the destruction or
combustion of towns' and other analogous refuse, consisting in the employment of
apparatus comprising in combination a fire-bed on which the material is burned,

page_text: with a plurality of closed ashpits below same, and a fire-brick chamber above,
common to all the fires and ashpits, and having a number of cleaning or cleaning
and charging doors and doorways, air heating tubes connected by conduits with
the furnace tubes and with the air and a hot air supply conduit to the ashpits, and
air blowers or forcing apparatus by which the air is carried through the air heating
chamber and delivered into and maintained in the ashpit at a pressure above that
of the atmosphere: substantially as herein set forth for the purposes specified.
2. An apparatus for the destruction or combustion of towns' or analogous refuse,
comprising a furnace having a plurality of closed ashpits with air forcing apparatus
by which air is maintained at a pressure above that of the atmosphere in them, and
a common fire-bed and furnace chamber with cleaning or cleaning and charging
doors and doorways above them, and adapted to operate as described; a steam
generator connected with said furnace and heated by the gases of combustion
thereof; and an air heater, connected with the steam generator flue or conduits,
and with the air, and the ashpits, disposed at the end of the apparatus between
said steam generator and furnace; arranged, combined, and adapted to operate
substantially as herein set forth.
3. In apparatus of the kind herein specified, the arrangement and construction of
air heater with tubes, chambers, and passages or conduits for the gases of
combustion and air, connected with the furnace which it supplies hot air to:
particularly as herein set forth with reference to and shewn in the drawings.
4. In apparatus of the kind herein specified, the steam jet blowers h, and air
conduits i, arranged and disposed as set forth with reference to and shewn in the
drawings.
5. The apparatus for destroying or burning towns' and like refuse, arranged,
constructed, and adapted to be operated, particularly as set forth with reference
to and shewn in Figures 1 to 3; and Figures 4 to 7 of the drawings, respectively.
Dated this 30th day of April 1897.
CHEESBROUGH & ROYSTON,
15 Water Street, Liverpool, Applicants' Patent Agents.