Improvements in Fuel Economisers or Feed Water Heaters, applicable also to Tubulous Steam Boilers.
Year: 1893

page_text: Date of Application, 4th Mar., 1893
Complete Specification Left, 6th Nov., 1893-Accepted, 13'h Jan., 1894
PROVISIONAL SPECIFICATION.
Improvements in Fuel Economisers or Feed Water Heaters,
applicable also to Tubulous Steam Boilers.
I, JAMES GARDNER CALVERT, of 19 Kyrkogatan, Gothenburg, in the
Kingdom of Sweden, Engineer, do hereby declare the nature of my said invention
to be as follows:
This invention relates more especially to that kind of fuel economiser or feed
water heater which consists of a number of vertical or more or less inclined pipes
or tubes arranged in series or sections, the upper ends of the pipes forming each
section being connected to a junction box in communication with the feed pipe
leading to the boiler; and the lower ends of the pipes forming each section
being connected to a junction box in communication with the feed water inlet
pipe and with the blow off pipe; but the invention is also more
applicable to tubulous steam boilers.
or less
In fuel economisers or feed water heaters of the above mentioned kind, the
feed water entering through the feed pipe is intended to be broken up into as
many separate currents as there are separate sections of pipes or tubes in the
economiser or heater, and each such current is intended to rise straight through
the particular section of pipes or tubes to which it happens to be directed and
then to go straight to the feed pipe leading to the boiler. It is now obvious
that if the feed water were forced to pass through all the sections of pipes or
tubes in succession, commencing with the section nearest the chimney and
finishing with the section nearest the furnace, the efficiency of the apparatus would
be very much increased; but heretofore this has not been found practicable because
of the unavoidable presence of the blow-off pipe which, being connected with all
the sections, enables the feed water to short circuit, so to speak, more or less
directly to the outlet pipe, unless each lower junction box is provided with a
separate sludge cock interposed between it and the blow-off pipe, which is an
inconvenient if not a wholly impracticable arrangement.
The chief object of my invention is to provide suitable and efficient means
whereby the blow-off pipe is shut off from the interior of the apparatus while the
latter is working but is easily, and in some cases automatically, conuected there-
with when it is required to blow off the sludge, and by these means the circulation
of the water through the apparatus is made certain.
For this purpose I employ a back-pressure valve between the lower junction box
of each section of the heating pipes or tubes and the blow-off pipe, that is to say
preferably a back-pressure valve for each separate section of such pipes; but in
some cases arrangements may be made whereby one back-pressure valve may be
made to serve for two, three, or more, of such sections.
These back-pressure valves may be constructed in any suitable way that will
allow the water and sludge to flow freely from each section of heating pipes to the
blow-off pipe when the main blow off cock or valve is opened, but will, when such
blow off cock or valve is closed, prevent the water flowing back from the blow-off
pipe to any of the said sections of heating pipes. A serviceable and cheap valve
for the purpose may consist of a hollow ball of glass, metal (such as iron, copper,
tin, aluminium, or alloy, for example) or other suitable material, or a solid ball of
some suitable light substance, floating upwards against a valve seat let into the
pipe junction between each section of heating pipes and the blow-off pipe. The
ball may be guided into its place by guide arms or rods which, when the main
blow-off cock or valve is opened, allow the ball to drop a sufficient distance to

page_text: permit of a free flow of water and any deposit from the sections of heating pipes to
the blow-off pipe, the ball naturally floating up to its seat as soon as the blow-off
cock or valve is shut. Instead of a floating ball, any other arrangement of valve
acting directly or indirectly by floatation may be employed, or any other suitable
kind of valve kept up to its seat by the pressure of a spring, a weight, or otherwise,
may be employed.
According to another arrangement the blow-off pipe may be shut off more or
less completely from the sections of heating pipes by means of a pipe contained
within and running the whole length of that part of the blow-off pipe where the
junctions from the sections of heating pipes are situated. This internal pipe fits
more or less accurately into the blow-off pipe and has holes formed in it corre-
sponding with the aforesaid junctions. It is adapted so that it can be turned
round at pleasure in the blow off pipe by means for example of a spindle connected
to it and passing out through a stuffing box on one end of the blow off pipe. By
this means the internal pipe can be turned so that the holes in it coincide with the
junctions of the section of heating pipes when it is desired to blow off, and with the
said holes away from such junctions when it is desired to close the connection
between the blow-off pipe and the sections of heating pipes. In some cases it may
be desirable and practicable to so fit the aforesaid internal pipe in the blow off
pipe as to entirely prevent the passage of the feed water along the blow off pipe
wher the internal pipe is turned with its holes away from the junctions, but in
most cases it will be sufficient to fit the said internal pipe somewhat loosely in the
blow off pipe, the passage way for the feed water to pass along the blow off pipe
being so reduced by the presence of the internal pipe that the quantity of water
that can pass between the external surface of the internal pipe and the internal
surface of the blow off pipe is not sufficient to cause any material inconvenience or
loss of efficiency in the apparatus.
The employment of the above mentioned back-pressure valves enables me to
arrange the economiser or heater in such a way as to insure the passage of the feed
water successively through all the sections of the heating pipes, the said feed
water preferably going in at the end nearest the chimney and coming out at the
end nearest the furnace whereby the hottest gases meet the hottest water, and the
coldest gases meet the coldest water, and to effect this, instead of connecting all
the lower junction boxes with the inlet feed pipe, and all the upper junction boxes
with the outlet feed pipe, as heretofore practised, 1 connect the upper junction box
of the first section of heating pipes by a connecting pipe with the lower junction
bex of the second section, the upper junction box of the second section by a con-
necting pipe with the lower junction box of the third section, and so on throughout
the apparatus. The feed water inlet pipe is connected to the lower junction box
of the first section and the feed water outlet pipe to the upper junction box of the
last section. By this arrangement the feed water enters the first lower junction
box, is forced to ascend through the first section of heating pipes, then down the
connecting pipe to the lower junction box of the second section, up the pipes of the
second section, down the connecting pipe to the lower junction box of the third
section, up the pipes of the third section, and so on throughout the apparatus until
it at last leaves by the feed outlet pipe at the upper junction box of the last
section. Thus the water is heated and allowed to rise slowly in every section of
pipes and is rapidly passed down through the connecting pipe to the bottom of the
next section. Or, if preferred, the sections may be connected together in sets of
two or more and the top of one set to the bottom of the next set by a suitable
arrangement of piping.
The connecting pipes may be placed inside or outside the flue as may be
preferred.
The continuous flow of the feed water through each section of heating pipes in
succession may also be effected by the following arrangement :-I connect the feed
water inlet pipe say to the lower junction box of the first section of heating pipes,
the upper junction box of that section with the upper junction box of the second

page_text: section, the lower junction box of the second with the lower junction box of the
third, the upper junction box of the third with the upper junction box of the fourth
and so on, and finally the feed water outlet with the upper or lower junction of the
Last section of pipes. By this arrangement the feed water is forced to ascend in
one section of pipes and to descend in the next; alternately ascending and descending
throughout the whole of the sections of pipes composing the apparatus.
Whichever of the two above described arrangements is employed, the before-
mentioned back-pressure or non-return valves prevent the passage of the feed water
by way of the blow off pipe instead of through the heating pipes.
In order to equalize the circulation of the feed water through all the pipes.
composing a section, I employ lower junction boxes having bottom sloping or
slanting upwards from the feed water inlet pipe; and upper junction boxes
having tops sloping or slanting upwards towards the feed water outlet pipe.
And in the ordinary arrangement of economiser or heater in which each section
of heating pipes is connected with the feed water inlet and outlet pipes, I
prefer to place the said junction boxes so that the tops of the upper boxes
slant upwards to one side where the feed water outlet pipe is situated, while
the bottoms of the lower boxes slant downwards to the opposite side where the
feed water inlet pipe is situated; but in the arrangements above described in
which the feed water is forced to pass through each section of pipes in succession,
the tops of the upper boxes, and the bottoms of the lower ones, may be made
to slant towards the same side. In some cases I also shape the part of the top
of the lower junction box where it joins the feed water inlet pipe so that it
slants upwards from the said inlet pipe, and the part of the bottom of the upper
junction box where it joins the feed water outlet pipe so that it slants upwards
towards the said outlet pipe.
Dated this 4th day of March 1893.
J. G. CALVERT,
Per W. H. Beck,
115, Cannon Street, London, Agent.
GODLY LEIL SPECIFICATION.
Improvements in Fuel Economisers or Feed Water Heaters,
applicable also to Tubulous Steam Boilers.
I, JAMES GARDNER CALVERT, of 19 Kyrkogatan, Gothenburg, in the Kingdom
of Sweden, Engineer, do hereby declare the nature of the said invention, and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement :-
This invention relates more especially to that kind of fuel economiser or feed
water heater which consists of a number of vertical or more or less inclined pipes
or tubes arranged in series or sections, the upper ends of the pipes forming each
section being connected to a junction box in communication with the feed pipe
leading to the boiler; and the lower ends of the pipes forming each section being
connected to a junction box in communication with the feed water inlet pipe and
with the blow-off pipe, but the invention is also more or less applicable to tubulous
steam boilers.
In fuel economisers or feed water heaters of the above mentioned kind, as
usually constructed, the feed water, entering through the feed pipe, is intended to
be broken up into as many separate currents as there are separate sections of pipes
or tubes in the economiser or heater, and each such current is intended to rise
straight through the particular section of pipes or tubes to which it happens to be
directed and then to go straight to the feed pipe leading to the boiler, but it is
obvious from the above that if the feed water were forced to pass through all the
sections of pipes or tubes in succession, commencing with the section nearest the

page_text: chimney and finishing with the section nearest the furnace, the efficiency of
the apparatus would be very much increased; but heretofore this has not been
found practicable because of the unavoidable presence of the blow-off pipe which,
being connected with all the sections, enables the feed water to short circuit, so to
speak, more or less directly to the outlet pipe.
The chief object of my invention is to provide suitable and efficient means
whereby the circulation of the water successively through all the sections of the
apparatus is made certain notwithstanding the presence of the blow-off pipe.
For this purpose I employ a back-pressure valve between the lower junction
box of each section of the heating pipes or tubes and the blow-off pipe, that is to
say, preferably a back-pressure valve for each separate section of such pipes; but
in some cases arrangements may be made whereby one back pressure valve may be
made to serve for two, three, or more, of such sections.
.And in order that my said invention may be readily understood I will now
proceed to describe the same with the aid of the accompanying three sheets of
drawings in which
Figure 1 is an elevation of an economiser or feed water heater constructed in
accordance with my invention, and placed in the flue between the furnace and the
chimney.
Figure 2 is a transverse sectional elevation, and Figure 3 a sectional plan of same.
Figures 4, 5 and 6 are similar views of a modified arrangement of same.
Figures 7, 8 and 9 are respectively transverse, longitudinal, and horizontal
sections of part of a blow-off pipe with one form of back-pressure valve applied
thereto.
Figures 10 and 11 are respectively longitudinal and transverse sections of part
of such a blow-off' pipe with another kind of valve applied thereto.
Figures 12 and 13 are respectively a longitudinal section and front elevation of
another arrangement of back-pressure valve, and Figures 14 and 15 similar views
of another modification thereof, Figure 16 being a section taken on line X X of
Figure 14, and Figure 17 an elevation of the valve shown in section in Figure 14.
The aforesaid back-pressure valves may be constructed in any suitable way
that will allow the water and sludge to flow freely from each section of heating
pipes to the blow-off pipe when the main blow-off cock or valve is opened, but
will, when such blow-off cock or valve is closed, prevent the water flowing back
from the blow-off pipe to any of the said sections of heating pipes. One form of
valve for the purpose is shown in Figures 7, 8 and 9. The valve may consist of
a hollow ball A of glass, metal (such as iron, copper, tin, aluminium, or alloy, for
example) or other suitable material, or a solid ball of a suitable light substance,
floating upwards against a valve seat B at the lower end of the pipe junction C
between each section of heating pipes and the blow-off pipe D. When the main
blow-off cock or valve (not shown in the drawings) is opened, the ball A drops
automatically and allows of a free flow of water and any deposit from the sections
of heating pipes to the blow-off pipe D, the ball A naturally floating up to its seat
as soon as the blow-off cock or valve is shut. In this arrangement the blow-off
pipe D is shown of oblong section with cylindrical enlargements D¹ where the
ball valves A occur. These cylindrical enlargements D' form guides for the ball
valves A. These latter are inserted through holes at the lower ends of the
cylindrical enlargements D' and rest, when allowed to fall by the opening of the
blow-off cock, on supports F formed on the cross bars F1 by which the plugs G,
which close the aforesaid holes, are held in place through the medium of the bolts
and nuts H.
Instead of a floating ball, any other other suitable kind of valve, kept to its seat
by the pressure of a spring or by gravity or otherwise, may be employed, such as
the ball A¹ for example shown in Figure 12, which, being heavier than water,
tends to roll by gravity down on the side ribs B2 to its seat B¹ when the blow-off
cock is shut. Or a simple flap valve A2, closing against its seat B², may be used as
shown in Figures 14 and 17. Or the blow-off pipe D may be shut off more or

page_text: less completely from the sections of heating pipes by means of an obturating
pipe A (see Figures 10 and 11) contained within and running the whole length
of that part of the blow-off pipe D where the junction branches C, from the
sections of heating pipes, are situated. This internal pipe A* is open at the end
next the blow-off cock and fits more or less accurately into the blow-off pipe D
and has holes A' formed in it corresponding with the aforesaid junction
branches C. It is adapted so that can be turned round at pleasure in the
blow-off pipe by means for example of a spindle A' connected to it at one end and
passing out through a stuffing box A on one end of the blow-off pipe D. By this
means the internal pipe A* can be turned so that the holes A' in it coincide with
the junction branches C of the sections of heating pipes when it is desired to
blow-off and with the said holes away from such junctions when it is desired to
close the connection between the blow-off pipe and the sections of heating pips.
In some cases it may be desirable and practicable to so fit the aforesaid internal
pipe in the blow-off pipe as to entirely prevent the passage of the feed water along
the blow-off pipe when the internal pipe is turned with its holes away from the
junctions, but in most cases it will be sufficient to fit the said internal pipe
somewhat loosely in the blow-off pipe, the passage-way for the feed water to pass
along the blow-off pipe being so reduced by the presence of the internal pipe that
the quantity of water that can pass between the external surface of the internal
pipe and the internal surface of the blow-off pipe is not sufficient to cause any
material inconvenience or loss of efficiency in the apparatus.
The employment of the above described back-pressure valves, or obturating
pipe, enables me to arrange the economiser or heater as shown in Figures 1 to 6
inclusive in such a way as to insure the passage of the feed water successively
through all the sections of the heating pipes, the said feed water preferably going
in at the end Y nearest the chimney and coming out at the end Z nearest the
furnace (see Figures 1, 3, 4 and 6) whereby the hottest gases meet the hottest
And to effect this, instead of
water, and the coldest gases meet the coldest water.
connecting all the lower junction boxes with the inlet feed pipe, and all the upper
junction boxes with the outlet feed pipe, as heretofore practised, I connect the upper
junction box I (see Figures 1, 2 and 3) of the first section of heating pipes Jby
a connecting pipe K with the lower junction box L² of the second section, the
upper junction box 12 of the second section J2 by a connecting pipe K² with the
lower junction box L³ of the third section J³ and so on throughout the apparatus.
The feed water inlet pipe M is connected to the lower junction box L' of the first
section and the feed water outlet pipe N to the upper junction box 15 of the last
section J. By this arrangement the feed water enters the first lower junction
box L1, is forced to ascend through the first section of heating pipes into the
upper junction box l', then down the connecting pipe K' to the lower junction
box L2 of the second section, up the pipes of the second section J2, into the upper
junction box 12, then down the connecting pipe K2 to the lower junction box L³ of
the third section, up the pipes of the third section J³ and so on throughout the
apparatus until it at last leaves by the feed outlet pipe N at the upper junction
box 18 of the last section. Thus the water is heated and allowed to rise slowly in
every section of pipes J to J8 and is rapidly passed down through the connecting
pipes K to K' to the bottom of the next section. Or, if preferred, the sections may
be connected together in sets of two or more and the top of one set to the bottom of
the next set by a suitable arrangement of piping.
The connecting pipes K¹ to K8 may be placed inside the flue P, or preferably
outside the same as shown in the drawings as that arrangement offers greater
facilities for repairs and inspection than that in which the pipes are placed inside
the flue.
The continuous flow of the feed water, through each section of heating pipes in
succession may also be effected by the arrangement shown in Figures 4, 5 and 6
in which I connect the feed water inlet pipe M say to the upper junction box l' of
the first section J' of heating pipes, the lower junction box L' of that section with

page_text: the lower junction box L² of the second section J', the upper junction box 12 of the
second section with the upper junction box 13 of the third section.J³, the lower junction
box L3 of the third with the lower junction box L of the fourth section .J* and so
on, and finally the feed water outlet N with the upper junction box 18 of the last
section of pipes J. By this arrangement the feed water is forced to ascend in one
section of pipes and to descend in the next; alternately ascending and descending
throughout the whole of the sections of pipes composing the apparatus.
The connection of the upper junction boxes in pairs and of the lower junction
boxes in the same way may be effected by plain U bends, but in the drawings I
have shown them connected by pipes Q and R respectively provided with branches
corresponding to the junction boxes to be connected together but each pair of
branches separated from the next pair by diaphragms Q' R' cast in the said
pipes Q and R respectively.
Figure 4 shows the back pressure valves A in the blow-off pipe D applied each
to a branch from the connection of two sections, whereby one valve is made to serve
for two sections of pipes as above mentioned.
Whichever of the two above described arrangements is employed, the before-
mentioned back-pressure or non-return valves or obturating pipe, as the case may
be, prevent more or less the passage of the feed water by way of the blow-off pipe
instead of through the heating pipes and force it to pass successively through all
the sections of heating pipes.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed I declare that what I
claim is :-
First. In a fuel economiser, feed water heater, or tubulous boiler, the employment
of a back-pressure valve between the lower junction box or boxes of one or more
sections of heating pipes or tubes, and the blow-off pipe, substantially as described,
and for the purpose specified.
Second. In a fuel economiser, feed water heater, or tubulous boiler, the employ-
ment of an obturating pipe in the blow-off pipe having openings corresponding to
the branches from the lower junction boxes of the sections of heating pipes or
tubes, arranged and operating substantially as described and for the purposes
:specified.
Third. The construction of a fuel economiser, feed water heater, or tubulous
boiler, which consists in connecting the upper junction box of each section of
heating pipes or tubes with the lower junction box of the next section by a
pipe K K etcetera, the blow-off pipe being shut off from the said lower junction
boxes by means of back-pressure valves or by means of an obturating pipe,
whereby circulation of the water upwards successively through all the sections of
heating pipes or tubes is effected, substantially as described, and illustrated in the
drawings.
Fourth. The construction of a fuel economiser, feed water heater, or tubulous
boiler, which consists in connecting the upper junction box of one section of
heating pipes or tubes with the upper junction box of the next section and the
lower junction box of one section of heating pipes or tubes with the lower junction
box of the next section, the blow-off pipe being shut off from the said lower
junction boxes by means of back-pressure valves, or by means of an obturating
pipe, whereby circulation of the water upwards and downwards alternately and
successively through all the sectious of heating pipes or tubes is effected, sub-
stantially as described, and illustrated in the drawings.
Dated this 4th day of November 1895.
10
J. G. CALVERT,
Per W. H. Beck,
115, Cannon Street, London, E.C., Agent.