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

page_text: Date of Application, 6th Apr., 1893
Complete Specification Left, 6th Jan., 1894-Accepted, 10th Mar., 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 déclare 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. or less applicable to tubulous
steam boilers.
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 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 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 circulation of the water through the apparatus is made certain
notwithstanding the presence of the blow off pipe.
For this purpose I employ, according to one arrangement, 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.
any
The aforesaid back pressure valves may be constructed in
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

page_text: °
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
suitable guides which, when, the main blow off cock or valve is opened, allow
the ball to drop automatically a sufficient distance to 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 flotation may be employed, or any other suitable kind of valve
kept up to its seat by the presence of a spring, a weight, or otherwise, may be
employed.
-
According to another arrangement the blow off pipe may be shut of more or
less completely from the sections of heating pipes by means of an obturating
pipe contained within and running the whole length of that part of the blow
off pipe where the junction branches 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 corresponding with the aforesaid junction branches.
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 junction branches 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 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 when the
internal pipe is turned with its hole 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 or obturating
pipe 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 hotest gases
meet the hotest 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,
I connect the upper junction box of the first section of heating pipes by a
connecting pipe with the lower junction box of the second section, the upper
junction box of the second section by a connecting 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 pipes 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.

page_text: The connecting pipes may be placed inside or outside the flue as may be
preferred.
In the arrangement above described, in which the upper junction box of each
section of heating pipes is connected by a pipe with the lower junction box of the
next section of heating pipes, I sometimes join the said connecting pipes to the
lower junction boxes by bends, and the blow-off pipe to the same junction boxes by
means of other bends of opposite curvature, so that the water flowing down the
connecting pipes is caused to enter the lower junction boxes. at considerable
velocity in a direction away from the blow-off pipe, and the tendency for the water
to flow to the blow-off pipe, even when the back-pressure valve is not present, is
wholly or partially prevented by the ejector-like action of the jet of water issuing
from the bend of the connecting pipe; this arrangement may therefore be employed
with or without the back-pressure valves.
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 upper junction box of the first section of heating pipes,
the lower junction box of that section with the lower junction box of the second
section, the upper junction box of the second section with the upper junction box
of the third, the lower junction box of the third with the lower junction box
of the fourth and so on, and finally the feed water outlet with the upper
junction box 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, or obturating pipe, or
ejector-like arrangements, 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.
In order to equalize the circulation of the feed water through all the pipes
composing a section, I employ lower junction boxes having bottoms sloping or
slanting upwards from the feed water inlet, or outlet, as the case may be, and
upper junction boxes having tops sloping or slanting upwards towards the feed
water outlet, or inlet, as the case may be; 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 and for the
purpose of assisting to equalize the circulation of the feed water through all
the pipes composing a section, I also shape the part of the top of the lower
junction box where it joins the feed water inlet, or outlet, as the case may be, so
that it slants upwards from such inlet or outlet and the part of the bottom of the
upper junction box where it joins the feed water outlet, or inlet, as the case may
be, so that it slants upwards towards such outlet, or inlet.
Dated this 6th dor of Anril 1803
J. G. CALVERT.
W. H. Beck,
Per S. E. Gunyon,
115, Cannon Street, London, Agent.

page_text: COMPLETE SPECIFICATION.
. Improvements in Fuel Economisers or Feed Water Heaters,
applicable also to Tubulous Steam Boilers.
I, JANES GARDNER CALVERT, of 19 Kyrkogatan, Gothenburg, in the
Kingdom of Sweden, Engineer, do hereby declare the nature of my said invention
and in what manner the same is to be performed to be particularly described
and ascertained in and by the following statement, that is to say :-
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 which has heretofore generally been
connected with the feed water pipe leading to the boiler, and the lower ends of
the pipes forming each section being connected to a junction box in communi-
cation 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 of similar construction.
In fuel economisers or feed water heaters of the abovementioned 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. It
is obvious however 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 in the ordinary construction of economiser or feed water
heater because of the unavoidable presence of the blow-off pipe, which, being
connected with all the sections, enables the feed water, or part of it, to short
circuit, so to speak, through the blow-off pipe, more or less directly to the outlet
pipe leading to the boiler.
In the Complete Specification of an application for a Patent No. 4775 dated the
4th March 1893 I have described certain arrangements of back pressure valves
interposed between the lower junction boxes and the blow-off pipe, and certain
modifications in the construction of the economisers or feed water heaters them-
selves, whereby the circulation of the water successively through all the sections
of pipes or tubes is made certain, notwithstanding the presence of the blow-off pipe ;
and the object of my present invention is to provide further improved means for
the same purpose, and these improved means may be used either in combination
with or independently of the said back pressure valves: they consist in so con-
structing and arranging the connecting pipe which conveys the water from one
section of heating pipes or tubes to the lower junction box of the next section of
heating pipes or tubes and the connection of such lower junction box to the blow-
off pipe in such manner that the water flowing through the connecting pipe is
caused to enter the lower junction box at considerable velocity in a direction away
from the blow-off pipe, whereby the tendency for the water to flow to the blow-off
pipe, even when the aforesaid back pressure valves are not present, is wholly or
partially prevented by the injector or ejector-like action of the jet of water issuing
from the connecting pipe into the lower junction box.
And in order that my said invention may be fully understood 1 will now proceed
to describe the same with the aid of the accompanying sheet of drawings, in which
Figure 1 is an elevation of an economiser or feed water heater constructed in
accordance with part of the improvements described in the Specification of my
aforesaid application for a Patent No. 4775 of 1893, Figure 2 is a transverse

page_text: sectional elevation of same taken on line W W of Figure 1, Figure 3 is a sectional
elevation, to a much larger scale, showing part of a lower junction box with my
injector and ejector devices applied thereto, and Figure 4 is a sectional elevation
taken on line X X of Figure 3.
In the economiser or feed water heater, shown in Figures 1 and 2, the upper
junction box 11 of the first section of heating pipes Jis connected by a return
pipe K with the lower junction box L2 of the second section, the upper junction
box 12 of the second section J2 by a return pipe K' with the lower junction box L³
of the third section J³, and so on throughout the apparatus. By this arrangement
the feed water enters at M, the first lower junction box L', is forced to ascend
through the first section of heating pipes J¹ into the upper junction box I', then
down the return pipe K¹ to the lower junction box L of the second section, up the
pipes of the second section J³ into the upper junction box I2, then down the return
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'.....
8 and is
rapidly passed down through the return pipes K¹ from the upper junction
7
to the lower junction boxes L'
8
8
boxes I...
Now according to my present invention, each of the return pipes K'... . . ‚ is
joined to its corresponding lower junction box L'. by a passage K*
preferably of curved form as shown in Figures 2 and 3, the outlet end of each such
passage being preferably contracted, as shown, to impart considerable velocity to
the issuing water. The connection of each said lower junction box L2...
with the blow-off pipe D is effected by means of a passage Ď×× of opposite curvature
or direction.
8
It will now be understood that the water flowing down the pipe K' is caused to
enter the lower junction box L³ at considerable velocity in a direction away from
the blow-off pipe D, and the tendency for the water to flow to the blow-off pipe D,
even when the back pressure valve A is not employed, is wholly or partially
prevented by the ejector-like action or induced current set up in the passage D**
by the jet of water issuing from the bend K* and directed across the mouth of the
passage Dxx.
In the Specification of my aforesaid application for a Patent No. 4775 of 1893,
I have also described an arrangement of the economiser or feed water heater in
which, instead of the upper junction boxes being connected to the lower junction
boxes of the next sections of heating pipes by connecting pipes K¹ etcetera, the
lower junction box of say the first section of pipes is connected by a bend or other
suitable passage with the lower junction box of the second section of pipes, the
upper junction box of the second section similarly with the upper junction box of
the third section, the lower junction box of the third section with the lower junction
box of the fourth section and so on throughout the apparatus. Now it will be
obvious that the end of the bend or other suitable passage, which forms the inlet of
water to any one of the lower junction boxes from the preceding lower junction
box, may be fitted with an injector or ejector apparatus similar to that above
described so as to utilise the velocity of the current of water flowing through the
said bend or passage to establish an ejector-like action or induced current from the
blow-off pipe towards the lower junction box which receives the water from
the preceding lower junction box.
Figure 5 illustrates diagrammatically an arrangement of this kind, in which J¹ J*
represent two adjacent sections of heating pipes, L' L' the corresponding lower
junction boxes, R the bend or passage forming the return pipe from the lower
junction box L¹ to the lower junction box L², K* the injector throat, and D** the
passage of opposite curvature or direction leading from the blow-off pipe D. The
arrow shows the direction of the current of water from the lower junction box L'
to the lower junction box L².
I desire to have it understood that I do not confine myself to the particular

page_text: forms of the pipes or passages forming the injector or ejector device as they may
be varied without departing from the nature of my invention.
°
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, an injector
or ejector device consisting of a passage K* connecting the return pipe to its
corresponding junction box, and a passage D** of opposite curvature or direction
connecting the said junction box to the blow-off pipe, substantially as described
with reference to the accompanying drawings and for the purpose specified.
Second. In a fuel economiser, feed water heater, or tubulous boiler, the combina-
tion of an injector or ejector device with a back pressure valve interposed between
the lower junction box and the blow-off pipe, substantially as described and for the
purpose specified.
Third. In a fuel economiser, feed water heater, or tubulous boiler, in which the
sections of heating pipes or tubes are so connected together as to allow the water
to circulate successively through all the said sections, the combination of an injector
or ejector device with the return pipe, blow-off pipe and lower junction box or
boxes of one or more sections of heating pipes or tubes, substantially as described,
and for the purpose specified.
Dated this 30th day of December 1909
J. G. CALVERT,
Per W. H. Beck,
115, Cannon Street, London, Agent.