provements in Water Circulating Fire-bars and Fuel Economizers for Steam Boilers.
Year: 1893

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Date of Application, 2nd Jan., 1893":
Complete Specification Left, 1st Nov., 1893 -Accepted, 27th Jan., 1894
PROVISIONAL SPECIFICATION
Improvements in Water Circulating Fire-bars and Fuel Economizers
for Steam Boilers.
WILLIAM KENHAM Boiler Maker 19 Emily, Street Stockton-on-Tees Durham.
I do hereby declare the nature of this invention to be as follows:
The water circulator and fuel economizer is à vessel independent of; yet
auxiliary to the steam boiler, its size, for an ordinary three foot furnace, would be'
twelve inches deep from the outside of the top to the outside of the bottom, and
three inches wide to the two outsides, this giving a two inches clear water space,
inside its form would be circular at the top and bottom, flat at the two sides and two
ends, it would be made of the best Lowmoor iron, or of the best boiler steel; seven
sixteenths thick and welded up at all the joints, the sides would be strengthened
by wrought iron stays one inch thick, these being screwed through from side to side
and then rivetted over, the whole being of sufficient strength to meet the require-
ments of the modern marine Lancashire or Cornish boilers of high pressure.
Its form, as, will be seen, is approximate to that of a fire bar; and its office to act
in the capacity of the same, it will lay in the fire bed taking the place of about.
two fire bars, being secured and made firm at each end; the front end to the, bearer"
bar of the furnace front, and the back end to the bearer. bar of the furnace bridge,
as shewn on Drawing I Fig 2 and thus being filled with water and lying in the
midst of the fire and receiving the fiercest heat, it will as a natural consequence
force a circulation; and from its position in the fire bed, it will use only what is
known as wasted heat, or that portion of heat, which is most destructive to the
fire bars. These circumstances giving the qualification for the names and titles
stated, viz. Improvements in water circulating fire bars, and fuel econom.izers for
steam boilers.
וי
Then the water being heated to boiling point in the circulator, means for its
circulation is provided for by-placing a-one-and-half-inch steam pipe in each end
efficiently secured by being screwed in with fine or gas thread and connected by
sockets and nuts, as shewn on Drawing. I Fig. 2 the front, end, forming the water
inlet, would be fixed to the bottom of the circulator, then taken either through the
bottom of the furnace, or carried outside to the bottom of the boiler front, thus
drawing the water from the bottom of the boiler, as shewn on Drawing I Fig: 2
then the back end circulating pipe would be fixed at the top of the circulator; and
carried through the fire bridge, and through the furnace to the back of the
combustion chamber, then by a bend in the pipe it would be taken up level with
the bottom of the tube plate, where by a bend again it would be taken through the
tube plate just under the tubes of the boiler, the nozzle end of the, circulating
pipe ends being bent upwards, so as to carry the circulating water. in' a' stream up
the tube plate, and amongst the tube ends of the boiler; thus effectually preventing
any sediment from lodging on these parts,..which would and does produce serious
leakage on that account.
But in cases where it is not practicable to get through the tube plate between
the boiler tubes and the furnace crown plate on account of their not being room
between them, then the circulating pipe would be carried from the circulator
through the furnace to the back of the combustion chamber, then by a bend, it
would be turned upwards and carried to the top of the combustion chamber, then

page_text: by a socket and nut connection, it would be taken through the crown plate
between the roof, or crown stays to a little over the water line of the boiler, then
by a bend again, as shewn by Drawing I Fig. 2 over the bottom row of
longitudinal stays and the box top, then by a bend again it would be taken down
through the water inside the boiler, round the bottom of the furnaces, until the
nozzle ends of the circulating pipes point upwards close to the back tube plate and
tube ends, and thus by their constant stream of water from the circulators would
prevent as before mentioned any sediment from finding a lodging place to interfere
with the action of the water upon these vital parts, which would create leakage.
Then as a precaution against the failure of the circulator, either through crack,
blister, or any other cause creating leakage, when the boilers are working and the
ship is at sea, a water cock would be provided and fitted, one at each end of the
circulator, as shewn on Drawing I Figs. 1 and 2 so that when the rent became
large and the leakage heavy, these could be shut off, and all water connection
with the boiler stopped; then the circulator would leak itself empty through the
leak or rent and act as a dead bar, until the ship came into port, when the injured
or worn out circulator could be taken out and replaced by a new one.
Then again where these cocks are used, it would be necessary to have a short pipe
connection from the bottom of the furnace to the circulating pipes running from the
circulator in the furnace to the back of the combustion chamber, as shewn on
Drawing Fig. 2 so that when the circulator is shut off from the boiler, the
circulating pipe in the combustion box, which would be still working, could draw
its water for circulation from this connection, when the circulator proper would be
acting as a dead bar.
Then for boilers of the Lancashire and Cornish types, the same arrangements
would be carried out, only the back circulating pipe would be carried through the
fire bridge to the necessary distance, then by a bend turned upwards, and so by
socket and nut, or by a flange connection carried through the centre of the flue at
the top to a little over the water line, then turned down again by a bend, and
carried down each side of the flue to a position near the bottom of the boiler, so
that the heated water from the circulators would be forced to the bottom of the
boiler forcing the cold water upwards over the flues to where the heat is and thus
effectually equalising the temperature of the water, also the plates of the boiler,
and rendering nil all danger of explosion arising from the cause of unequal
expansion.

page_text: Improvements in Water Circulating_Fire-bars and Fuel Economizers
for Steam Boilers.
I, WILLIAM KENHAM, formerly of 19, Emily Street, Stockton-on-Tees in the
County of Durham but now of 11, Bremner Street, Ardwick, Manchester, in the
County of Lancaster, Boilermaker do hereby declare the nature of this invention
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
The object of this invention is to provide for the better circulation of water,
and to economise fuel in steam generators. For this purpose I provide in place of
some of the ordinary fire-bars one or more hollow vessels or fire-bars connected
by suitable pipes with the water space of the boiler at points above and below the
furnace so that the water can circulate freely through it or them when the fires are
lighted.
And in order that my invention may be fully understood I will now describe with
reference to the accompanying illustrative drawings, the best way known to me of
carrying it into practical effect.
In the said drawings,
Fig. 1 shows partly in cross section, and partly in front end elevation with the
fire-door frame plate removed, a cylindrical marine multi-tubular boiler having my
invention applied thereto.
Fig. 2 is a section on the line a b of Fig. 1.
The
A, A are the hollow water circulating fire bars of which, in the example shown,
there are two applied to each furnace. These fire bars, which may advantageously
be formed of the best quality Lowmoor iron or boiler steel with their edges pre-
ferably welded together and of sufficient width to occupy the space of three of the
ordinary fire bars B are made with rounded or semi-circular upper and lower parts
and flat sides and ends, the sides being strengthened by cross stays A' so as to
withstand the full boiler pressure. Each of them is suitably supported at its ends
preferably by angle iron brackets A* upon the front and rear bearers C C¹
respectively that carry the ordinary fire bars, so that its upper part extends above
the level of the ordinary fire bars B as shown, and is connected by pipes D, D¹
respectively with the water space below and above the furnace flue E.
pipe D, which serves as an inlet pipe to the hollow bar, is connected at one end d
with the water space below the furnace whilst its other end d'enters the corre-
sponding hollow bar at the lower front end thereof, whilst the pipe D' which
serves as an outlet or discharge pipe leads from the upper rear end of the said
corresponding hollow bar through the fire bridge E' to the water space above the
furnace as shown. These pipes D D' may be of any suitable kind such as copper
pipes. The upper ends D² of some of the outlet pipes D¹ may be so arranged that
the water that passes therefrom is discharged horizontally over the crown of the
furnace or parallel to the tubes whilst others D³ may be so arranged that the water
is discharged in an upward direction. The water from these latter pipes will
impinge against the tube plate and so prevent any sediment accumulating at the
joints between the tubes and plate and at the same time prevent overheating of
the latter. To this end each of the pipes D₁ is carried by a double bend round
the back of the smoke box or combustion chamber E* and passed through the tube
plate, under the tubes. Here it is bent parallel to the tube plate and brought to
the crown of the furnace flue so as to enter the water space immediately above the
furnace as indicated in Figs. 1 and 2. The ends of some of the tubes (D2) are
bent in a horizontal direction, whilst others (D³) are bent in an upward direction
in order to promote an efficient flow or circulation of water over and amongst the

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tubes. Connections of ordinary or suitable kinds are of course provided at the
various pipe joints and at the places where the pipes pass through the boiler
plates. A suitable cock F the plug of which is provided with a crank F¹ and a
rod F2 for turning it, serves to close the communication between the upper part of
the boiler and the hollow bar A when necessary as for example in case of cracking
or serious leakage of the said hollow bar. A cock G is also provided in the inlet
pipe D with the same object. The cock F may be replaced by a non-return valve
if desired.
In either case it is protected from injury by heat by being situated
behind the fire-bridge and beneath a plate E2 which may be covered with fire-
bricks. To prevent the production of an undue pressure within the hollow fire
bars when the same are disconnected from the water space above and below the
furnace flue by the closing of the cocks F and G, each hollow fire bar is provided
with a safety valve as shown at A³..
A branch pipe may be arranged to lead from the pipe D' to the lower water
space independently of the hollow bar A in order to maintain a certain amount of
circulation through the pipe D' when the cocks F and G are closed. This branch
pipe is provided with a stop cock by which it can be closed when the hollow bar is
acting properly and it is not required to be used.
When applying my invention to boilers of the Lancashire and Cornish type,
each discharge pipe D¹ is after being carried back some distance beyond the fire
bridge passed through the crown of the furnace flue as shown in Figs. 3 and 4
which are respectively a half cross section and a longitudinal section of a Lancashire
boiler. In this case each outlet pipe D' is led upward inside the boiler to a point
slightly above the water level and then bent over and led down to the bottom
portion of the boiler some of them in the case of the Lancashire boiler passing
between the furnace flues and others being curved and led downward between the
boiler shell and the adjacent furnace flue. With such an arrangement the hot
water discharged from the said outlet pipes displaces the water lying below the
furnace and causes the same to move into a position where it would be more
efficiently heated. The pipes D' are each provided with one or more air
holes D so that when the boiler is being fed with water the latter can freely rise
therein.
Water circulating fire bars such as described may advantageously be each made
about 12 inches deep, and three inches across externally and of metal about in.
thick, so as to form a water channel of 11 inches in depth by 2 inches in width.
By forming and arranging the said hollow firebars in the manner described, they
become heated in an economical and efficient manner so that a very efficient water
circulation will be maintained in the steam boiler, thereby rendering the temperature
of all parts of the boiler uniform, or practically so, and obviating unequal expansion
and consequent wear and tear of the boiler, at the same time effecting a considerable
economy in the fuel employed.
In some cases as in large furnaces, three or more water circulating fire bars such
as described may be used and I would have it understood that the other details of
the invention may be departed from to suit special circumstances without departing
from the essential features of my invention.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
-
1. In a steam boiler, one or more water circulating fire bars and fuel economisers
such as A each being arranged and extending above the level of the ordinary fire
bars B so as to become embedded in the fuel on the fire grate and provided with
pipes fitted with valves, whereby its ends can be placed in communication with the
water space of the boiler above and below the furnace flue, the arrangement being
such that when the boiler is at work, an effective circulation of water will be set
up through the said hollow fire bar substantially as herein described for the purpose
specified,

page_text: 2. A hollow water circulating fire bar and fuel economiser for a steam boiler,
constructed substantially as described and shown for use in the manner set forth for
the purpose specified.
3. In a steam boiler, water circulating fire bars and fuel economisers constructed
arranged and operating substantially as hereinbefore described with reference
respectively to and shown in Figs. 1 and 2, and in Figs. 3 and 4 of the drawings
annexed, or modified as set forth.
Dated this 31st day of October 1802
Per pro EMMOTT & CO., LIMITED,
ROBERT WOOD, Secretary,
2, New Bridge Street, Manchester, Agents for the Applicant.