AN IMPROVED STEAM GENERATOR
Year: 1880

page_text: LETTERS PATENT to Leighton Mills, of Tynemouth, in the County of
Northumberland, Engineer, for an Invention of "AN IMPROVED STEAM
GENERATOR,"
PROVISIONAL SPECIFICATION left by the said Leighton Mills at the Office
of the Commissioners of Patents on the 16th July 1880.
LEIGHTON MILLS, of Tynemouth, in the County of Northumberland, Engineer.
"AN IMPROVED STEAM GENERATOR."
My Invention consists of an outer shell of iron or other suitable material of a
circular or other convenient form; this is fitted with an inner firo or combustion
chamber also of suitable material, and of such dimensions as to leave a water space
all around it, and a steam and water space above it. The lower part of such water
space below the level of the fire grate is enlarged, by turning inwards the bottom
end of the material of the inner chamber, or by the addition of angles and
suitably formed plates, and by forming sides and a bottom joining it to the outer
shell.
This obtains a horizontal plate surface all round or along the sides of the lower
part of the fire chamber, and if separate flue chambers are fitted, along those also.
The horizontal plate surfaces are pierced with one or more rows of holes, and to
these tubes are fitted; the tubes reach up to and through holes in the roof of the
fire or flue chamber.
The tubes are made secure in their holes by the usual means of-expanding or
screwing. From their position they surround the fire in a vertical or practically
vertical position, the heat from which has free action upon them, and they form a
connection between the upper water and steam space and the enlarged part of the
water space at the lower part of the generator. The arrangement as above
described is for the purpose of causing an upward current of the water through the
tubes, and a downward current by the water space between the outer shell and fire
chamber.
The generator instead of being as above described, may be formed by an 'upper
water and steam chamber, and by one or more bottom water chambers.
These chambers being joined by one or more sets of vertical or practically
vertical tubes, the tubes themselves thus forming the outer and inner water spaces,
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page_text: the fire being surrounded by the innermost set.
higher than the level of the bottom of the tubes.
The fire grate is always placed
The products of combustion in either arrangement are carried off by flue tubes of
convenient size, number, and form, passing through the upper water and steam
spaces.
The whole or part of the structure may be enclosed in a casing of iron or other
suitable material.
My improved steam generator is fitted with all necessary stops and feed valves,
steam domes, chimney, gauge glasses, cocks, and all usual furniture.
'
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Leighton Mills in the Great Seal Patent Office on the 15th January
1881.
LEIGHTON MILLS, of Tynemouth, in the County of Northumberland, Engineer.
"AN IMPROVED STEAM GENERATOR."
My Invention consists of an outer shell of iron or other suitable material of a
circular or other convenient form; this is fitted with an inner firo or combustion
chamber also of suitable material, and of such dimensions as to leave a water space
all around it, and a steam and water space above it. The lower part of such water
space below the level of the fire grate is enlarged by turning inwards the bottom
end of the material of the inner chamber, or by the addition of angles and
suitably formed plates, and by forming sides and a bottom joining at the outer
shell.
This obtains a horizontal plate surface all round or along the sides of the
lower part of the fire chamber, and if separate fluo chambers are fitted, along
those also.
The horizontal plate surfaces are pierced with one or more rows of holes, and to
these tubes are fitted; the tubes reach up to and through holes in the roof of the
fire or flue chamber.
The tubes are made secure in their holes by the usual means of expanding or
screwing. From their position they surround the fire in a vertical or practically
vertical position, the heat from which has free action upon them, and they form a
connection between the upper water and steam space and the enlarged part of the
water space at the lower part of the generator. The arrangement as above
described is for the purpose of causing an upward current of the water through the
tubes, and a downward current by the water space between the outer shell and fire
'chamber.
The generator instead of being as above described may be formed by an upper
water and steam chamber, and by one or more bottom water chambers, these
chambers being joined by one or more sets of vertical or practically vertical tubes,

page_text: the tubes themselves thus forming the outer and inner water spaces, the firo being
surrounded by the innermost set. The fire grate is always placed higher than the
level of the bottom of the tubes.
The products of combustion in either arrangement are carried off by flue tubes
of convenient size, number, and form, passing through the upper water and steam
spaces.
the tubes themselves thus forming the outer and inner water spaces, the firo being
surrounded by the innermost set. The fire grate is always placed higher than the
level of the bottom of the tubes.
The products of combustion in either arrangement are carried off by flue tubes
of convenient size, number, and form, passing through the upper water and steam
spaces.
The whole or part of the structure may be enclosed in a casing of iron or other
suitable material.
My improved steam generator is fitted with all necessary stops and feed valves,
Figuros 1, 1º, 2, 2ª, 3, 3ª, and 3b, illustrate the forms in which I prefer and
propose to make my steam generator; Figures 1, 10, and 2 and 2º, show it in a
circular form, and Figures 3, 30, and 3b, in a rectangular form.
In Figures 1 and 2, C is the upper steam and water chamber; A is an uptako
tube of which three may be a sufficient number to afford the required area;
B, B, are the rows of tubes connecting the upper chamber with the lower water
chamber D, which in this case is annular in form. The upper and lower end plates
of the upper chamber may be stayed by ordinary bow stays, by the tubes forming
the uptakes, or, in conjunction with them or not, a central tube E may be fitted, as
shewn, which may or may not be used as an uptake tube.
The fire bars rest on the upper part of the lower water chamber, as shewn.
More than two rows of tubes may be fitted, and a sufficient number are left out
opposite the fire door for stoking purposes.
Generally the upper chamber is made of sufficient depth to allow of any of the
tubes being removed or inserted in caso of repairs, as in Figure 2; but in lieu of
this the top of the upper chamber may be bolted on by means of a flange, as in
Figure 1, whero the height is limited.
The tubes are made tight on thin plates by the usual methods of expanding at
the top from the upper chamber, and at the bottom they may be also expanded by
inserting the expandor through the ordinary cleaning holes of the bottom chamber,
and working it by means of a box spannor inserted down the tubo from the top.
end; or other suitable means may be adopted for fixing the tubes in their plates,
Buch as screwing in either with or without stay nuts.
The products of combustion are carried through the uptake tubes A, A, as
shewn on Figures 1 and 2, or in lieu of them, where space allows, the upper
chamber C may be divided by an annular space F, such space answering the
purpose of the uptake tubes A, Å.
The inner and outer portions of the upper chamber C on each side of the annular
tube F are connected by openings formed of flanged rings rivetted in, or by tubes
passing through the annular space and expanded or screwed, see Figure 2, at C¹
and C. The outer row of water tubes is cased in by any convenient material,
either in the form of an earing or boiler composition by which as well the whole
boiler may be protected.
Figures 3, 3, and 3b show the steam generator in a rectangular form, Figure 3
being a longitudinal section; Figure 3ª, a sectional plan one half above tube plate
of upper chamber C, and one half through furnace (on line C, D, of Figure 3);
Figure 3b is an end view one half in section. Two rows of tubes B, B, are shewn
on each side of the fire grate, but more may be fitted if thought necessary.
The heated gases from the fire pass upward through the spaces between the inner,
and along the space between the inner and outer rows of tubes on either side to the
uptakes A, A, which in this instance are shewn only at each end, but may however
be increased in number and ranged along the sides of upper chamber C, passing
through and being mado secure in the top and bottom plates, or flanged and

page_text: rivetted thereto. This steam generator may be cased in at the sides, as described
per Figures 1 and 2, and the ends may be fitted with casings where necessary
bound with iron conducting material, so arranged as to guide the products of
combustion from the furnace through the spaces between the rows of tubes, thence
to the uptake tubes leading to the chimney; or the uptake tubes may be dispensed
with and separate uptakes attached to the ends of the boiler. A series of any of
these forms of steain generator may be connected by means of a steam receiver, or
by enlarging the upper steam and water chamber, and increasing the number of
lower water chambers with thin tubes to form additional furnaces.
In all the arrangements above described all or a sufficient number, of the tubes
may be screwed at one or both ends and screwed into one or both plates to form
stay tubes or not.
This arrangement of steam generator or other or the same principle are to be
fitted-with-all-the usual-and-necessary furniture, valves, cocks, water gauges,
pressure gauges, hand and manholes with doors, feed and steam valves, &c.
Having now described my Invention with reference to the accompanying
Drawings, I declare that what 1 consider novel and secured to me by Letters
Patent to be,-
The improved steam generator, constructed, arranged, and operating substantially
as herein before described.
In witness whereof, I, the said Leighton Mills, have hereunto set my hand.
and seal, this Eleventh day of January, in the year of our Lord One
thousand eight hundred and eighty one.
LEIGHTON MILLS. (L.S.)

page_text: LETTERS PATENT to Leighton Mills, of Tynemouth, in the County of
Northumberland, Engineer, for an Invention of "AN IMPROVED STEAM
GENERATOR."
PROVISIONAL SPECIFICATION left by the said Leighton Mills at the Office
of the Commissioners of Patents on the 16th July 1880.
LEIGHTON MILLS, of Tynemouth, in the County of Northumberland, Engineer.
"AN IMPROVED STEAM GENERATOR."
My Invention consists of an outer shell of iron or other suitablo material of a
circular or other convenient form; this is fitted with an inner fire or combustion
chamber also of suitable material, and of such dimensions as to leave a water space
all around it, and a steam and water space above it. The lower part of such water
space below the level of the fire grate is enlarged, by turning inwards the bottom
end of the material of the inner chamber, or by the addition of angles and
suitably formed plates, and by forming sides and a bottom joining it to the outer
shell.
This obtains a horizontal plate surface all round or along the sides of the lower
part of the fire chamber, and if separate flue chambers aro fitted, along those also.
The horizontal plate surfaces are pierced with one or more rows of holes, and to
these tubes are fitted; the tubes reach up to and through holes in the roof of the
fire or flue chamber.
The tubes are made secure in their holes by tho usual means of expanding or
screwing. From their position they surround the fire in a vertical or practically
vertical position, the heat from which has free action upon them, and they form a
connection between the upper water and steam space and the enlarged part of the
water space at the lower part of the generator. The arrangement as above
described is for the purpose of causing an upward current of the water through the
tubes, and a downward current by the water space between the outer shell and fire
chamber.
The generator instead of being as above described, may be formed by an upper
water and steam chamber, and by one or more bottom water chambers. These
chambers being joined by one or more sets of vertical or practically vertical tubes,
the tubes themselves thus forming the outer and inner water spaces, the fire being

page_text: surrounded by the innermost set. The fire grate is always placed higher than the
level of the bottom of the tubes.
The products of combustion in either arrangement are carried off by flue tubes of
convenient sizo, number, and form, passing through the upper water and steam
spaces.
The whole or part of the structure may be enclosed in a casing of iron or other
suitable material.
My improved steam generator is fitted with all necessary stops and feed valves,
steam domes, chimney, gauge glasses, cocks, and all usual furniture.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Leighton Mills in the Great Seal Patent Office on the 15th January
1881.
LEIGHTON MILLS, of Tynemouth, in the County of Northumberland, Engineer.
"AN IMPROVED STEAM GENERATOR."
My Invention consists of an outer shell of iron or other suitable material of n
circular or other convenient form; this is fitted with an inner fire or combustion
chamber also of suitable material, and of such dimensions as to leave a water space
all around it, and a steam and water space above it. The lower part of such water
space below the level of the fire grato is enlarged by turning inwards the bottom
end of the material of the inner chamber, or by the addition of angles and
suitably formed plates, and by forming sides and a bottom joining at the outer
shell.
This obtains a horizontal plate surface all round or along the sides of the
lower part of the fire chamber, and if separate flue chambers are fitted, along
those also.
The horizontal plate surfaces are pierced with one or more rows of holes, and to
these tubes are fitted; the tubes reach up to and through holes in the roof of the
fire or flue chamber.
The tubes are made secure in their holes by the usual means of expanding or
screwing. From their position they surround the fire in a vertical or practically
vertical position, the heat from which has free action upon them, and they form a
connection between the upper water and steam space and the enlarged part of the
water space at the lower part of the generator. The arrangement as above
described is for the purpose of causing an upward current of the water through the
tubes, and a downward current by the water space between the outer shell and fire
chamber.
The generator instead of being as above described may be formed by an upper
water and steam chamber, and by one or more bottom water chambers, these
chambers being joined by one or more sets of vertical or practically vertical tubes,

page_text: the tubes themselves thus forming the outer and inner water spaces, the fire being
surrounded by the innermost set. The fire grate is always placed higher than the
level of the bottom of the tubes.
The products of combustion in either arrangement are carried off by flne tubes
of convenient size, number, and form, passing through the upper water and steam
spaces.
Figures 1, 1, 2, 2, 3, 3ª, and 3b, illustrate the forms in which I prefer and
propose to make my steam generator; Figures 1, 14, and 2 and 2, show it in a
circular form, and Figures 3, 3, and 3b, in a rectangular form.
In Figures 1 and 2, C is the upper steam and water chamber; A is an uptake
tube of which there may be a sufficient number to afford the required area;
B, B, are the rows of tubes connecting the upper chamber with the lower water
chamber D, which in this case is annular in form. The upper and lower end plates
of the upper chamber may be stayed by ordinary bar stays, by the tubes forming
the uptakes, or, conjunction with them or not, a central tube E may be fitted, as
shewn, which may or inay not be used as an uptake tube.
The fire bars rest on the upper part of the lower water chamber, as shewn.
More than two rows of tubes may be fitted, and a sufficient number are left out
opposite the fire door for stoking purposes.
Generally the upper chamber is made of sufficient depth to allow of any of the .
tubes being removed or inserted in case of repairs, as in Figure 2; but in lieu of
this the top of the upper chamber may be bolted on by means of a flange, as in
Figure 1, where the height is limited.
The tubes are made tight in their plates by the usual methods of expanding at
the top from the upper chamber, and at the bottom they may be also expanded by
inserting the expandor through the ordinary cleaning holes of the bottom chamber,
and working it by means of a box spannor inserted down the tube from the top
end; or other suitable means may be adopted for fixing the tubes in their plates,
such as screwing in either with or without stay nuts.
The products of combustion are carried through the uptake tubes A, A, as
shewn on Figures 1 and 2, or in lieu of them, where space allows, the upper
chamber C may be divided by an annular space F, such space answering the
purpose of the uptake tubes A, A.
The inner and outer portions of the upper chamber C on each side of the annular
tube F are connected by openings formed of flanged rings rivetted in, or by tubes
passing through the annular space and expanded or screwed, see Figure 2, at C¹
and C. The outer row of water tubes is cased in by any convenient material,
either in the form of air casings or boiler composition by which as well the whole
boiler may be protected.
Figures 3, 3, and 3b show the steam generator in a rectangular form, Figure 3
being a longitudinal section; Figure 34, a sectional plan one half above tube plate
of upper chamber C, and one half through furnace (on line C, D, of Figure 3);
Figure 3b is an end view one half in section. Two rows of tubes B, B, are shewn
on each side of the fire grate, but more may be fitted if thought necessary.
The heated gases from the fire pass upward through the spaces between the inner,
and along the space between the inner and outer rows of tubes on either side to the
uptakes A, A, which in this instance are shewn only at each end, but may however
be increased in number and ranged along the sides of upper chamber C, passing
through and being made secure in the top and bottom plates, or flanged and
Q8985. Wt. P 1813.

page_text: rivetted thereto. This steam generator may be cased in at the sides, as described
per Figures 1 and 2, and the ends may be fitted with casings where necessary
lined with non conducting material, so arranged as to guide the products of
combustion from the furnace through the spaces between the rows of tubes, thence
to the uptake tubes leading to the chimney; or the uptake tubes may be dispensed
with and separate uptakes attached to the ends of the boiler. A series of any of
these forms of steam generator may be connected by means of a steam receiver, or
by enlarging the upper steam and water chamber, and increasing the number of
lower water chambers with their tubes to forin additional furnaces.
In all the arrangements above described all or a sufficient number of the tubes
may be screwed at one or both ends and screwed into one or both plates to form
stay tubes or not.
This arrangement of steam generator or other on the same principle are to be
fitted with all the usual and necessary furniture, valves, cocks, water gauges,
pressure-gauges, hand and manholes with doors, feed and steam valves, &c.
-
Having now described my Invention with reference to the accompanying
Drawings, I declare that what I consider novel and secured to me by Letters
Patent to be,
The improved steam generator, constructed, arranged, and operating substantially
as herein before described.
In witness whereof, I, the said Leighton Mills, have hereunto set my hand
and seal, this Eleventh day of January, in the year of our Lord One
thousand eight hundred and eighty one.
TOTA