IMPROVEMENTS IN STEAM GENE- RATORS
Year: 1877

page_text: LETTERS PATENT to Arthur Greenwood, of Leeds, in the County of York,
Machine Maker, for the Invention of "IMPROVEMENTS IN STEAM GENE-
RATORS."
Sealed the 6th July 1877, and dated the 12th January 1877.
PROVISIONAL SPECIFICATION left by the said Arthur Greenwood at the
Office of the Commissioners of Patents on the 12th January 1877.
ARTHUR GREENWOOD, of Leeds, in the County of York, Machine Maker.
PROVEMENTS IN STEAM GENERATORS."
"IM-
This Invention relates chiefly to the construction of small generators for high
pressure steam where gas or hydrocarbon products are employed as fuel; solid fuel
however may be used, and the generators may be made of large as well as of small
capacity.
The steam generator is provided with a vertical water reservoir of as small
capacity as circumstances will admit of, and it is composed of a flanged tube plate
which forms the inner end wall of the furnace, and a curved front plate, the
flanges of which are connected with the tube plate by means of bolts and nuts.
The front plate is so shaped as to give to the water reservoir such an internal
form as will provide the largest plane area at the height destined for the water.
level.
The tube plate is fitted with a set of syphon-shaped tubes, which extend along
nearly the whole length of the furnace, and are severally fixed in vertical planes.
The lower limbs of these tubes are set at an angle to each other; and the lower
limbs being in the hottest part of the furnace, there will be a tendency for the water
supplied to the tubes to flow upwards through them, and discharge into the upper
part of the water reservoir.
An inlet is provided near the bottom of the front plate for the admission of the
feed water, and the upper part of this plate carries a safety valve.
Within the furnace and at the upper part thereof a pipe of large capacity is pro-
vided for receiving the steam as it is generated. The steam reservoir is secured to
the upper part of the tube plate and set at or about the same angle of inclination
as the lower limbs of the water tubes; and as the heated gases are free to circulate
around it, the steam will become superheated before it leaves the generator.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Arthur Greenwood in the Great Seal Patent Office on the 12th July
1877.
ARTHUR GREENWOOD, of Leeds, in the County of York, Machine Maker.
PROVEMENTS IN STEAM GENERATORS."
"IM-
This Invention relates chiefly to the construction of small generators for high
pressure steam, the object being to produce steam in a rapid and economical
manner.
The fuel employed may be gas or hydrocarbon products, or solid fuel may be used
when fire-bars are fitted to the combustion chamber.
The steam generator is provided with a vertical water chamber of as small
capacity as circumstances will ȧdinit of, and it is composed of a flanged tube plate
which forms one of the walls of the furnace, and a curved front plate, the flanges of
which are connected with the plate by means of bolts and nuts.
The front plate is so shaped as to give to the water chamber such an internal
form as will provide the largest plane area at the height destined for the water
level.
The tube plate is fitted with a set of syphon-shaped tubes, which extend along
nearly the whole breadth of the furnace and are severally fixed in vertical planes
The limbs of these tubes are set at an angle to each other to facilitate the flow
through the tubes of the water supplied thereto.
Within the furnace and at the upper part thereof a pipe of large capacity is pro-
vided for receiving the steam as it is generated. This steam chamber is secured to
the upper part of the tube plate, and at or about the same angle of inclination as
the lower limbs of the water tubes; and as the heated gases are free to circulate
around it, the steam will become superheated before it leaves the generator.
In the accompanying Drawing, Fig. 1 is a side elevation of the improved steam
generator, the outer case being in section; and Fig. 2 is a vertical section of the
same taken in the line 1, 2, of Fig. 1.
A is the fire chamber, the walls of which are made for the sake of portability of
a double sheet-iron case B, B, filled with some suitable nonconducting substance,
but fire-brick walls may be used when thought desirable. C is the tube plate in
which are fitted syphon-shaped water tubes D, D, which extend across nearly the
whole width of the fire chamber, and are arranged in vertical planes; the tubes of
each vertical row being out of line with tubes of the adjacent rows in order the
better to intercept the ascending flames and heated gases generated by the com-
bustion of the fuel.
In front of the tube plate is a plate E which at its upper part is made concave on
its inner face for the purpose to be presently explained. This plate E is secured by
bolts and nuts to the tube plate in such manner as to provide a water and steam
space F between the two plates, from which the tubes will receive their supply of
water, and into which they will discharge it when heated or when converted into
steam. The capacity of this chamber I make only sufficient to ensure, first, a proper
circulation of the water therein; and, secondly, the free escape of the steam from the
water. The ordinary water level of the boiler will be at the line *, *, Fig. 2, in
which line the largest surface area of the water will be provided in the chamber F
by reason of the concavity of the plate E at that part. By thus enlarging the
surface area of the water in the chamber F, the rise of the steam to the surface will
be facilitated.
Above the water tubes D the tube plate is fitted with an enclosed tubular steam
chamber G, into which the steam from the chamber F will pass to be superheated.
His a pipe which passes up through the chimney I and leads off the steam from the
steam chamber to the engine required to be driven. K is a safety valve fitted to the
steam chamber G and weighted in the usual manner.

page_text: Water is supplied to the lowest part of the chamber F by a pipe L in connection
with a supply pump or reservoir. As the water enters the boiler it will pass into
and through the several syphon tubes, and discharge at an increased temperature
into the chamber F. It will then pass through syphon tubes higher in the series
to be again discharged into the chamber F.
By the unequal temperatures to which the two limbs of the syphon tubes are
exposed an efficient circulation of the water will be maintained throughout the
boiler, and thus a rapid discharge of steam into the enlarged or upper part of the
chamber F will result.
Having now set forth the nature of my Invention for "Improvements in Steam
Generators," and explained the manner of carrying the same into effect, I wish it to
be understood that under the above in part recited Letters Patent I claim the
arrangement in steam generators of syphon tubes, as shewn in the Drawings, in
connection with a water and steam chamber of contracted capacity, such chamber
being by preference contracted to a minimum below the water line and enlarged at
the water level, as and for the purpose above described.
In witness whereof, I, the said Arthur Greenwood, have hereunto set my
hand and seal, the Sixth day of July, in the year of our Lord One thousand
eight hundred and seventy-seven.
ARTHUR GREENWOOD. (L.S.)