Refuse Destructor and Steam Generator Combined.
Year: 1895

page_text: Date of Application, 13th Sept., 1895
Complete Specification Left. 20th Mar.. 1896-Accepted, 30th May, 1896
Date of Application, 13th Sept., 1895
Complete Specification Left. 20th Mar.. 1896-Accepted, 30th May, 1896
Refuse Destructor and Steam Generator Combined.
JOHN CHARLES COLTMAN ERNEST EDWIN COLTMAN WALTER WILLIAM
COLTMAN HURAM COLTMAN Engineers (Mechanical) all of Midland Ironworks
Loughborough Leicestershire, do hereby declare the nature of this invention to be
as follows:-
The object of our invention is to produce a steam generator, which when used in
combination with a furnace adapted for destroying, or burning refuse fuels such as
coke breeze town refuse and the like shall utilize to a greater extent, than has
hitherto been the case, the heat generated by the combustion of such refuse and
fuels, for steam raising purposes, at the same time avoiding the loss by radiation to
which those refuse destructors are liable whose furnaces are constructed or built
externally to or apart from the steam generator, and therefore usually necessitate
a more or less considerable length of flues before the hot gases, reach the steam
generator or boiler, the great extent of brickwork or masonry, in such furnaces
and flues, exposed to the atmosphere, naturally permitting the escape of a large
proportion of the heat units, arising from the combustion of the fuel on the
furnace grate.
Our invention therefore is designed to permit of large quantities of fuel of
inferior quality, & low calorific value, being burnt directly under, or within, the
steam generator, on a furnace grate of much larger area in proportion to the
heating surface of the boilers, than is customary or practicable in Cornish,
Lancashire, & other internally fired boilers, & for that purpose we construct a
steam generator, consisting of three cylindrical boilers, fixed in such a position in
relation to each other that, when seen in cross section, there is one at each end of
the base and one at the apex of a triangle.
Each of the two lower boilers, is connected with the upper one, by a continuous
junction or water casing for the full length of the boilers, or such other length as may
be found preferable in practice, & also by means of water tubes if deemed desirable.
Between the two lower boilers, at or below the level of their centres, the furnace
grate is fixed & consists of firebars specially adapted for burning dust fuels with
forced or natural draught. It will be seen that the arrangement gives a combustion
chamber, approximating in cross section to a triangle, the base being formed by
the firebars & the sides by the two boilers, with the water casings connecting them
with the third boiler at the apex.
As however such an arrangement though well adapted for steam raising with
fuels of high calorific value may be open to the objection that for towns refuse &
similar poor fuels, a combustion chamber enclosed entirely by metal surfaces in
contact with water & therefore incapable of storing up such a reserve of heat as
may be desirable or necessary when renewing the fires with fresh refuse fuel & that
consequently a fall in steam pressure might take place during and immediately after
such renewing of the fires.
To do away with any such possible objection we propose to form at a suitable
height above the fire, an arch or covering of firebricks or blocks, carried on fire
brick blocks, placed at each side of the furnace grate, or otherwise suitably
supported, such firebricks or blocks, to be of suitable thickness for the purposes
intended: viz. -to store up a reserve of heat & reflect it on to the newly made fire,

page_text: and also to intercept dust particles which might otherwise be blown from the
fire by the forced draught and cause to impinge detrimentally on the surfaces of
the boilers, exposed to the blast.
The fire brick cover, or arch, last referred to is carried over the furnace
grate, or firebars parellel, longitudinally, to the surface of such bars & is
therefore, either level or sloping according as the grate may be set level or inclined
from the front, or clinkering doors, to the drying hearth. From the back end of
the grate bars, a sloping drying hearth commences, on to which the refuse fuel is
thrown through the charging doors, at the back or opposite end of the furnace to
the clinkering doors referred to, over the drying hearth, the firebrick cover or arch
above referred to is carried at the same inclination longitudinally as the hearth.
The direction of the flow of the hot gases, may be thus described, the air passes
from the underside of the firebars, through the fire and into the first combustion
chamber, formed by the grate and the fire brick cover or arch referred to escaping
thence, into chamber No. 2. at the front or opposite end to the drying hearth thus
drawing the fumes from the drying refuse over the fire grate, this second chamber
is enclosed partly, by the three boilers and the water casing sides connecting the
two lower boilers with the upper one, and partly by the upper surface of the fire
brick furnace crown before referred to, the hot gases then leave the second chamber
at the back end and divide to right & left, passing through chamber numbered 3,
enclosed by the outer faces of the three boilers, and the water casings, and the
fire brick arch or wall, and passing down at the front end, into chamber + under
the bottoms of the two lower boilers finally escaping into the main flue at the back
of the destructor, and then thence to the chimney.
Dated this Twelfth day of September 1895.
JOHN CHARLES COLTMAN.
ERNEST EDWIN COLTMAN.
WALTER WILLIAM COLTMAN.
HURAM COLTMAN.
JOHN CHARLES COLTMAN Meadow Lane Loughborough ERNEST EDWIN
COLTMAN Meadow Lane Loughborough WALTER WILLIAM COLTMAN Bridge
Street Loughborough HURAM COLTMAN Park Road Loughborough, each and
all of whom are Mechanical 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:-
The object of our invention is to produce a ** refuse destructor" and steam
generator the combination of which with a furnace is adapted for burning and
destroying at a high temperature town refuse, colliery refuse, coke, breeze, and
other fuels of low calorific value, and shall utilize to a greater extent than has
hitherto been the case the heat generated by the more perfect combustion of such
town refuse and fuels for steam raising purposes, at the same time avoiding the loss
by radiation or premature escape to which those refuse destructors are liable whose
furnaces are constructed or built externally to or apart from the steam generator,
and therefore usually necessitate a more or less considerable length of flues before
the hot gases or heat units reach the steam generator or boiler, the great extent of
brickwork or masonry in such furnaces and flues exposed to the atmosphere
naturally permits the escape and loss of a large proportion of the valuable heat
units already obtained from the combustion of the before mentioned refuse and
fuels on the furnace grate.
Our invention is therefore designed to permit of large quantities of fuel of

page_text: inferior quality and low calorific value being burnt directly under or within the
steam generator upon a suitable furnace grate and thereby to give more perfect
combustion and better results than are otherwise obtained, and for this purpose we
construct a steam generator of three cylindrical boilers A, A' & A' fixed in such
a position in relation to each other, that when seen in cross section there is one at
each end of the base, and one at the apex of a triangle; each of the two lower
boilers is connected with the upper one by a continuous junction or water way B
and B for the full length of the boilers or such other length as may be found
preferable in practice, the junctions B & B or waterways form heating surface
and divisional walls preventing the units of heat escaping directly from furnace
into chimney without passing along the several chambers in the direction herein-
after described, thus bringing the whole of the heat in contact with the whole
heating surface of the boiler.
Water tubes, t, t, t, are inserted and connect the several boilers and intercept the
heat in the several chambers. Between the two lower cylinders or boilers at or
below the level of their centres the furnace grate C is placed and consists of
stationary or moving firebars specially adapted for burning the fuels mentioned by
means of forced or natural draught; it will be seen that the above arrangement
gives very large combustion chambers, approximating in cross section to a triangle
the base being formed by the firebars C the sides by the two boilers A' & A'
with the water-boxes B & B connecting them with the third boiler A. at the apex.
To ensure a reserve of heat necessary for the burning of the town refuse and
other inferior fuels, to prevent the fall of steam pressure when the furnace is
replenished and to aid in subsequent combustion we place at a suitable height above
the fire an arch or covering D of fireblocks which may be supported by the boilers
or upon fireblocks placed at each side of the furnace grate or otherwise suitably
supported, such fireblocks to be of approved thickness for the purpose intended,
viz. to store up a reserve of heat and reflect it upon the newly made fire; this
fireblock cover or arch is carried over the furnace grate or firebars parallel
longitudinally to the surface of such bars, and is therefore either level or sloping
according as the grate may be set level or inclined from the front or clinkering
doors E to the drying hearth F. From the back end of the grate bars a sloping
drying hearth F commences, upon which the refuse or fuel is thrown or fed through
the charging doors G at the back or opposite end of the furnace to the clinkering
doors E referred to.
The direction of the flow of the hot gases or heat units may be thus described, the
air passes from the underside chamber H upwards and between the firebars through
the fire and into the first chamber K formed by the grate C and the firebrick
cover D escaping thence into chamber K' by the front or opposite end to the
drying or feeding hearth, thus drawing the fumes from the drying refuse over the
firegrate, this second chamber K' is enclosed partly by the three boilers A, A¹ & A²
and the waterways B & B connecting the two lower boilers with the upper one,
and partly by the upper surface of the fireblock furnace cover D; the hot gases
then leave this the second chamber K at the back or charging end dividing to the
right and left passing into the chambers L & L', called the third chambers, these
chambers are enclosed by the outer faces of the three boilers, the water ways and
the firebrick walls M & M'; the water tubes t, t, t, found in this chamber absorb
their portion of the heat remaining as it passes through towards the front end,
thence downward into chambers N & N¹ situated under the bottoms of the two
lower boilers, finally escaping into the main flue at the back or feeding end of the
destructor thence into chimney.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim are
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page_text: 3. To get a more powerful and efficient plant in a smaller space than is obtained
by any existing arrangement.
AYM
JOHN CHARLES COLTMAN.
ERNEST EDWIN COLTMAN.
WALTER WILLIAM COLTMAN
HURAM COLTMAN.