IMPROVEMENTS IN AND RELATING TO THE FLUE-TUBES OF STEAM-BOILERS
Year: 1884

page_text: I, WILLIAM CLARK, of 19 Leo Street, Plumstead, in the County of Kent,
Engincer, do hereby declare the nature of my invention for "IMPROVEMENTS IN
AND RELATING TO THE FLUE-TUBES OF STEAM-BOILERS" to be as follows:-
My invention relates to the flue-tubes of steam-boilers, and is designed to
increase the strength of the said tubes and enable them to offer a greater resistance
to external pressure, and also to increase the heating surface of the said flue-tubes
and facilitate the circulation of the water within the boiler.
In carrying my said invention into practice I prefer to form the flue-tube by
rolling or otherwise, into a series of regular or irregular corrugations with plain
portions between them and with plain portions at the ends to form the joints.
By constructing the tubes in this manner I.greatly increase their power of resisting
external pressure.
To increase the heating surface of flue-tubes I insert therein water-tubes bent or
curved to correspond with the circumference of the flue-tube. The whole length
of flue-tube, or any part of it, may be provided with these curved water-tubes, and
they may extend more or less around the interior of the said flue-tubes. The said
water-tubes may be connected to the flue-tubes at two or more points, but I prefer
to connect them at three points, that is to say, the two ends of the said water-tubes
are connected to the flue-tubes at a convenient distance from the bottom or lower
part of the same, and the intermediate portion of the water-tube is connected with
the top or crown of the said flue-tube. Suitable holes are formed in the flue-plates
for the reception of the said ends and intermediate portion of the water-tubes, the
metal around them being swaged or bulged up to thicken and strengthen the
plates at the parts that receive the said water-tubes, which may be expanded and
fixed in the said holes according to the well known method of fixing tubes in
boilers. The water enters the bent tubes at the two ends and escapes at the top
aperture; I thus ensure a continuous circulation from the lower to the higher parts
of the boiler and a very rapid evaporation of the water.

page_text: The aforesaid bent or curved water-tubes are arranged within the plain portions
of flue-tubes constructed as above described. But tho said water-tubes can be
conveniently fitted to existing ordinary plain cylindrical flue-tubes without
removing them from the boiler, the ends of the said tubes being pressed inwards
and the tube then passed through the flue-tube until the ends of the water-tube
enter the holes provided to receive them.
When properly arranged the said water-tubes will ensure a very efficient action
of the heated currents in passing along the flue and a more rapid evaporation of
the water in the boiler.
Dated this 24th day of June 1884.
HASELTINE, LAKE & Co.,
For the Applicant.

page_text: I, WILLIAM CLARK, of 19 Lee Street, Plumstead in the County of Kent,
Engineer, do hereby declare the nature of my invention for "IMPROVEMENTS IN
AND RELATING TO THE FLUE-TUBES OF STEAM-BOILERS" and in what manner the
same is to be performed, to be particularly described and ascertained in and by
the following statement:—
•
My invention relates to the flue-tubes of steam-boilers and is designed to
augment the beating surface of the boiler, and to facilitate or improve the
circulation and evaporation of water therein.
For this purpose I employ, in combination with such flue-tubes, curved water-
tubes through which the water in the boiler can freely pass, and which are acted
upon by the heated air and gases in the said flue-tube, as hereinafter set forth.
In the accompanying drawing, I have shewn how my said invention may be
conveniently and advantageously carried into practice.
Figure 1 is a sido elevation of a corrugated Blue-tube provided with water-tubes
according to my present invention.
Figure 2 is a side elevation, and
Figure 3 is a transverse section of a plain cylindrical flue-tube provided with the
said water-tubes.
a indicates the flue-tube, b, b are the water-tubes, which are bent or curved, as
shewn in Figure 3, so that, when properly inserted, they are concentric with the
said tube. The said water-tubes may be connected to the flue-tube at two or moro
points, but I prefer to connect them at three points, that is to say, the two ends of
each water-tube are connected to the flue-tube at a convenient distance from the
bottom or lower part of the same, as shewn at b¹, and the intermediate portion of
tho said water-tube is connected with the top or crown of the fluo-tube, as shewn
at 6. Suitable holes are formed in the flue-plates for the reception of the said
water-tubes, the metal around these holes being, by preference, swaged or thickened
to strengthen the said plates at these parts. The said water-tubes are fixed in the
said holes by expanding them according to the well known method of fixing tubes
in boilers.
In the specification of former Letters Patent dated 10th October A.D. 1871,
No 2688, I have described flue-tubes made with corrugations to increase their
strength and augment their heating surface. When the said water-tubes are to be
applied to flue-tubes of this class, I prefer to make the latter, as shown in Figure 1,
with alternate plain or cylindrical portions a¹ and circumferential indentations or
depressions a². For this purpose, I first form a plain cylindrical fluc-tube with a
welded joint, I then place the said flue-tube in a furnace until the required heat is
obtained and pass it through a set of rolls which are so constructed as to impart to
it the form shewn. I insert the water-tubes b into the plain portions a¹, and, by
reason of the shape of the latter, I am enabled to make proper joints and prevent
leakage around the tubes.
The said water-tubes can be conveniently fitted to existing plain cylindrical
flue-tubes, in which they may, if desired, be inserted without removing the said
flue-tubes from the boiler. For this purpose, the ends of the water-tubes are
pressed inwards and the said tubes are passed through the flue-tube until their
ends and intermediate branches or connections enter the holes at b¹ and b³ provided
for their reception.
In Figures and 3, a indicates a plain cylindrical fluc-tube, which is provided
with water-tubes as above described.

page_text: In each or either of the flues of a boiler, I insert a series of theso water-tubes,
and, when properly arranged, they ensure a very efficient action of the heated air
and products of combustion passing along the fluc.
The whole length of the flue-tube, or any part thereof, may be provided with
these curved water-tubes, and they may extend more or less around the interior
of the said tube.
When the boiler is in operation, the water enters the said water-tubes at the
two ends b' and escapes nt b. A continuous circulation of water from the lower
to the higher parts of the boiler, and a very rapid evaporation therein are thus
ensured.
I have shewn the water-tubes arranged at right angles to the axis of the flue-
tubes, but it is obvious that I might attain the desired results by arranging them
at any other suitable angle thereto.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is =
-
The employment, in combination with a boiler fluc-tube (either plain or
corrugated), of a series of curved water-tubes arranged within the said flue-tube
and connected therewith at two or more points, substantially as, and for the
purposes, set forth.
Dated this 30th day of December 1884.
HASELTINE, LAKE & Co.,
For the Applicant.