IMPROVEMENTS IN TUBULAR STEAM BOILERS
Year: 1878

page_text: LETTERS PATENT to Benjamin Joseph Barnard Mills, of the Firm of Harris
and Mills, of 23, Southampton Buildings, in the County of Middlesex, Patent
Agent, for the Invention of "IMPROVEMENTS IN TUBULAR STEAM BOILERS."
A communication from abroad by Julius Gustav Schmidt, Manufacturer, of
Berlin, in the Kingdom of Prussia, and Empire of Germany.
Sealed the 12th July 1878, and dated the 28th January 1878.
PROVISIONAL SPECIFICATION left by the said Benjamin Joseph Barnard
Mills at the Office of the Commissioners of Patents on the 28th January
1878.
BENJAMIN JOSEPH BARNARD MILLS, of the Firm of Harris and Mills, of 23,
Southampton Buildings, in the County of Middlesex, Patent Agent.
"IMPROVE-
MENTS IN TUBULAR STEAM BOILERS." A communication from abroad by Julius
Gustave Schmidt, Manufacturer, of Berlin, in the Kingdom of Prussia, and Empire
of Germany.
The Invention relates to that class of tubular steam boilers in which zig-zag
series of tubes or pipes are united to each other and to the water and steam drums
or chambers by elbows, and in which are used more than one series of these tubes
or pipes, and the object of the Invention is partly to utilise in the best manner
the heat of the fuel by the counter current of the fire and water, and partly to
generate completely dry steam.
According to the present Invention the feed water enters by a check valve into
the feed water heater, and thence flows into the lower zig-zag row of tubes until
all the water tubes of the water reservoir and the lowest row of the steam tubes
are filled with it. The steam generator is composed of these steam tubes, joined
together by elbows so as to form two or more vertical zig-zag series of tubes, which
Drinn GJ1

page_text: are connected at the bottom with the water drum or chamber and at the top with
the steam drum or chamber from which the steam for driving purposes is
taken off.
The fire burning in the furnace envelopes the lowest row of the tubes of the
steam generator which are filled with water, but passes therefrom directly through
the flue to the top of the water reservoir, and enveloping its tubes it flows from
there down into the flue and into the chimney.
The lower row of tubes of the steam generator, which are filled with water, are
exposed to the direct action of the fire, and all the other tubes of the steam
generator are filled with steam and subjected only to the radiant heat of the
burning fuel. On the way from the grate to the chimney the products of com-
bustion take a direction exactly opposite to that of the feed water, coming at the
beginning in contact with its hottest and leaving it on its coldest part, therefore
the heat of the fuel is used at the greatest advantage.
The steam generated and contained in the steam generator is not subjected to
the direct action of the flames, but the radiant heat of the burning fuel is sufficient
to make it perfectly dry.
For the regulation of the flow of the water from the water reservoir to the steam
generator a cock fitted with a regulating valve is interposed between them.
All the other fittings, valves, cocks, and otherwise of the boiler may be as usual,
as may also be the details of construction of the boiler itself.
Heretofore the counter current of the fire and the water has not been fully
utilised, but according to the present Invention this problem is satisfactorily
solved.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by the
said Benjamin Joseph Barnard Mills in the Great Seal Patent Office on the
26th July 1878.
BENJAMIN JOSEPH BARNARD MILLS, of the Firm of Harris and Mills, of 23,
Southampton Buildings, in the County of Middlesex, Patent Agent. "IMPROVE
MENTS IN TUBULAR STEAM BOILERS." A cominunication from abroad by Julius
Gustave Schmidt, Manufacturer, of Berlin, in the Kingdom of Prussia, and Empire
of Germany.
The Invention relates to that class of tubular steam boilers in which zig-zag
series of tubes or pipes are united to each other, and to the water and steam drum
by elbows and in which are used more than one series of these tubes, and the object
of it is partly to utilize in the best manner the heat of the fuel by the counter
current of the fire and water, and partly to generate completely dry steam.
In the accompanying Drawing,-
Figure 1 represents a vertical longitudinal section of the boiler; Figure 2, half
a front view and half a vertical cross section; Figure 3, a horizontal section.
Figure 4, a modification of the boiler represented at Figures 1, 2, 3, in which
the water tubes are carried nearly to the level of the upper row of steam tubes.
According to the present Invention the feed water enters by a check valve c
at K into the feed water heater H, flows from there into the lower zig-zag row of
tubes A, A, until all the water tubes of the water reservoir and the lowest row of
the steam tubes are filled with it. The steam generator is composed of steam
tubes B, B, joined by elbows so as to form two or more vertical zig-zag series of
tubes, which are connected at the bottom with the water drum or cylinder C and
at the top with the steam drum or cylinder D, from which the steam for driving or
other purposes is taken off.
The flame and products of combustion from the fire burning upon the grate E
impinge upon the lowest row of the steam tubes, which is filled with water and
but a few of those containing only steam, but pass therefrom directly through the
flue W to the top of the water reservoir, and enveloping its tubes they pass from
there down into the flue F and into the chimney.
The lower row of tubes of the steam generator are filled with water and all the
other tubes of the steam generator are filled with steam, and to the greater part
subjected only to the radiant heat of the burning fuel. On their way from the
grate to the chimney the flame and products of combustion from the fire take a
direction exactly opposite to that of the feed water, coming at the beginning in
contact with its hottest and leaving it on the coldest part, therefore the heat of the
fuel is used to the greatest advantage.
The steam generated and contained in the steam generator B, represented at
Figures 1, 2, 3, is only to a small extent subjected to the direct action of the flames,
but in the arrangement shown at Figure 4 more of such steam tubes are subjected
to the direct action of the flames; but the radiant heat of the burning fuel is
sufficient to make it perfectly dry.
For the regulation of the flow of the water from the water reservoir, which may
be under high pressure, to the steam generator of a lower pressure the cock L fitted
with a regulating valve is interposed between them.
All the valves, cocks, and other fittings of the boiler may be as usual, as may
also be the details of the construction of the boiler itself.
There is also no necessity to place the water and steam reservoir exactly as
shown in Figures 1 to 3, but these two systems of tubes may be placed as in
Figure 4, or in any other convenient position.
Heretofore it has not been possible to utilize to the full extent the counter
current of the fire and the water, but the present Invention solves this problem
satisfactorily.

page_text: Having thus described the nature of the said Invention, and the mode of carrying
the same into effect, I would have it understood that what I claim and desire to
secure by Letters Patent is,-.
First. The separate high-pressure water reservoir composed of water tubes of a
tubular boiler in combination with the steam generator, in which the same or a
lower pressure than in the water reservoir may be maintained and of which only
the lower row of tubes is filled with water, for the purpose specified, and sub-
stantially as described.
Second. The construction of the steam generator of a tubular boiler n such way
that the greater part of its steam-containing tubes are subjected only to the radiant
heat of the burning fuel, whilst all the tubes containing water are subjected to the
direct heat of the flame and products of combustion passing in a direction opposite
to the current of the feed water.
Third. The employment of a cock L, fitted with a regulating valve, in combi-
nation with tubular boilers, constructed with high-pressure water reservoir
separated from the steam generator, which are arranged in such way that the flame
and products of combustion pass on in a direction opposite to the current of the
water, and situated as shown, and for the purpose specified.
In witness whereof, I, the said Benjamin Joseph Barnard Mills, have hereunto
set my hand and seal, this Fifth day of July, in the year of our Lord One
thousand eight hundred and seventy-eight.