IMPROVEMENTS IN BOILERS OR APPARATUS APPLICABLE TO THE GENERATION OF STEAM AND TO OTHER PURPOSES
Year: 1867

page_text: LETTERS PATENT to Benjamin Harlow, of Macclesfield; in the County.
of Chester, Mechanical Engineer, for the Invention of "IMPROVEMENTS
IN BOILERS OR APPARATUS APPLICABLE TO THE GENERATION OF STEAM AND TO
OTHER PURPOSES."
Office of the Commissioners of Patents, with his Petition and Declaration,
on the 2nd August 1867, pursuant to the 9th Section of the Patent Law
Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, BENJAMIN
ARLOW, of Macclesfield, in the County of Chester, Mechanical Engineer,
send greeting.
WHEREAS I am in possession of an Invention for "IMPROVEMENTS IN
BOILERS OR APPARATUS APPLICABLE TO THE GENERATION. OF STEAM AND TO OTHER
PURPOSES," and have petitioned Her Majesty to grant unto me, my executors,
administrators, and assigns, Her Royal Letters Patent, for the same, and have
made solemn Declaration that I believe the said Invention will be of great
public utility, and that I am the true and first Inventor thereof.
NOW KNOW YE, that I, the said Benjamin Harlow, do hereby declare
that the following Complete Specification, under my hand and seal, fully
describes and ascertains the nature of the said Invention, and in what manner
the same is to be performed, in and by the following statement:-
The said Invention has for its object improvements in boilers or apparatus
applicable to the generation of steam and to other purposes, and refers to that
class of boilers or beating apparatus in which a hollow drum situated at the

page_text: upper part of the furnace is connected around or near to its circumference by
means of vertical water pipes or tubes (situated in the furnace, and wholly or
partly surrounding the fire), with a hollow or water ring also surrounding the
fire, and in contact with the burning fuel, the water to be heated being
contained in or circulating through the hollow drum, connecting pipes, or tubes
and ring.
Now in such boilers as hitherto constructed the pipes connecting the drum
with the ring as described have consisted of ordinary straight pipes opening at
one end into the drum, and at the other into the ring, but according to my
Invention I make use of double pipes situated parallel to each other, and
connected together near to the upper and lower ends of one of the pipes, as
shewn in Figs. 1 and 2 of the accompanying Sheet of Drawings, which are
respectively an elevation and plan of a boiler or apparatus constructed according
to my Invention, one of the double tubes being left out in Fig. 1 for the
purpose of shewing the interior.
It will be seen that the pipes or tubes a are open at their upper ends to the
drum b, and at their lower ends to the ring c, the pipes d being directly
connected only (by means of short tubular passages e) with the pipes or
tubes a. In this instance the double pipes a and d are cast or formed in one
piece, as shewn in Fig. 3, or they may be of the form shewn in Fig. 4,
according to the form or desired depth of the boiler. The pipes or tubes a are
situated farther from the centre of the furnace than the pipes or tubes d,
which latter consequently form an inner circle more immediately exposed to
the action of the fire. f is a hollow ring for supporting the hollow fire-bars g,
which are fitted in with sockets, as shewn in plan at Fig. 4*, and this ring f
is connected by a pipe h with the ring c; i is the flow pipe, and the charge
hole for fuel. In some cases I form the hollow double fire-bars as shewn in
plan at Fig. 10.
In some cases I provide the apparatus with bearings cast on the under ring
for solid fire-bars, and when it is desirable to dispense with this portion
altogether the flange joint on the boiler may be used for the return pipes.
The fixing of this apparatus in brickwork is effected in the manner ordinarily
practised with boilers or apparatus of the class to which it refers, but with an
additional flue over the top portion of the tubes for the purpose of giving
increased heating surface.
Fig. 5 shews to an enlarged scale another modification of double tube
according to my Invention, and formed or cast entirely in one piece, the closed
lower end of the tube d being continued downward to some distance below its
lower point of connection with the pipe or tube a.

page_text: Fig. 6 shows an arrangement of double tube constructed of wrought iron
according to my Invention, 7 being an elbow; m, "T's;" and n, a bend, the
remaining portions being lengths of ordinary tubing, excepting the part o
which is a pocket.
Fig. 7 is a modification of the arrangement shewn in Fig. 6, the tube being
in this case formed with a straight head piece p, upon which the crown of the
boiler may be cast instead of its being jointed, as in the foregoing arrange-
ment. Otherwise in some cases I dispense with the inner row of tubes above
described, and in lieu thereof I construct the tubes of the outer row of a broad
flat form, as shewn in section at Fig. 8, in such manner as that a portion of
each such tube projects inwards into a position equivalent to that occupied by
the tubes of the inner rows in the preceding arrangements, thus obtaining a
broad water or steam space in each tube. By the means described, and as
the outer circle formed by the double pipes or tubes or broad flat tubes as
described is also subjected to the full action of the furnace, a large and very
effective heating surface equivalent or nearly equivalent to a double row of
ordinary tubes is obtained, but with only half the number of joints between
the tubes, drum, and ring that would in the case of such double row be
necessary. Boilers as described, when suspended or set in furnaces of brick-
work by which they are entirely surrounded and which leave a space between
the interior surface of the brickwork and the outer parts of the boiler, are
especially suitable for beating water for public buildings, horticultural and
other purposes, in which cases the water after being beated flows away as
required through a pipe inserted in the drum at the top of the boiler, as
described, and is returned by a similar pipe leading into the under side of the
ring at the bottom of the boiler, as will be seen in the Drawing, the furnace
being fed from the top by means of the hole passing through the centre of the
drum, and stoked at the bottom beneath the ring of the boiler by means
of a hole passing through the side of the furnace. Boilers as described may
be used in connection with ordinary boilers and otherwise for the generation
of steam, and where desirable may be enclosed in a wrought or cast iron
case made to take the place of ordinary brickwork.
Fig. 9 shews my improved boiler as used in connection with an ordinary
boiler, the improved boiler being set as described, partly beneath one end of
the ordinary boiler and connected therewith by means of a suitable pipe or
pipes for maintaining a proper circulation between the two. The flame and
beated products of combustion after passing from the furnace of the improved
boiler are carried beneath or through the flues of the ordinary boiler.
One important feature in my improved boilers is that in the event of injury

page_text: to a double or broad flat tube it can be readily taken out and replaced without
disturbing any other part of the boiler.
Boilers or apparatus according to my Invention may be conveniently employed
in the flues of puddling, or other furnaces, and may likewise be advantageously
employed in the manufacture of salt from brine, the brine passing through one
or two boilers, according to the quality of salt required, and passing from them
into the common evaporating pans.
In some cases I employ a fire under one boiler, and heat other boilers by
the products of combustion passing from such fire.
Having now described the nature of my said Invention, and in what
manner the same may be conveniently carried into effect, I would have it
distinctly understood that I do not confine myself to the precise forms or
details herein-before described and represented in the accompanying Sheet of
Drawings, as the same are susceptible of being variously modified to meet the
requirements of particular cases without departing from the distinctive features
of my Invention, with reference to which I claim,-
Firstly, the use or employment in boilers or apparatus applicable to the
generation of steam and to other purposes of double tubes or broad flat tubes
arranged, formed, or constructed substantially as herein-before described and
illustrated in the accompanying Sheet of Drawings for the purposes set
forth.
Secondly, the construction of hollow double fire-bars with one joint or
connection only at each end, substantially as described and illustrated.
In witness whereof, I, the said Benjamin Harlow, have hereunto set my
hand and seal, this Second day of August, in the year of our Lord One
thousand eight hundred and sixty-seven.
°
BENJAMIN HARLOW. (L.S.)