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

page_text: Date of Application, 18th Sept.. 1893
Complete Specification Left, 16th June, 1894-Accepted. 25th Aug., 1894
PROVISIONAL SPECIFICATION.
Improvements in Fuel Economisers or Feed-water Heaters,
applicable also to Tubulous 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, feed
water heater, or boiler, 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 an upper junction box and the lower ends
of the pipes forming each section being connected to a lower junction box, which
latter is in communication with the blow-off pipe.
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 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 this has not been found practicable with the ordinary arrangements
because of the unavoidable presence of the blow-off pipe, which, being connected
with the lower junction boxes of all the sections, euables the feed water to short
circuit, so to speak, more or less directly to the outlet pipe.
In order to provide means whereby the feed water can be made to circulate
through the entire apparatus notwithstanding the presence of the blow-off pipe, I
have devised certain arrangements of back pressure valves interposed between the
blow-off pipe and the lower junction boxes and certain connections of the junction
boxes with one another whereby the feed water is forced to traverse each section
of pipes in succession.
These devices form the subject of an application for a Patent by me now
pending.
Now my present invention relates to further improvements in connection with
the above mentioned devices for securing circulation through all the sections in
succession, and the object of these further improvements is to provide means for
improving the circulation through the sections. In certain arrangements of the
devices above mentioned the feed water is conveyed from the upper junction box
of one section to the lower junction box of the next by a down pipe and there is
a connecting passage between the said lower junction box and the blow-off pipe, in
which passage the beforementioned back pressure valve is placed. The water
enters the lower junction box from the aforesaid down pipe at a velocity which
somewhat assists the circulation through the next section of pipes. But I have
found that the greater the velocity of entry within proper limits of the water
into the lower junction box the better; and to facilitate this, I make the connec-
tion of the down pipe, with the lower junction box, of a curved form, and the
connection of the lower junction box, with the blow off pipe, of a similar curved
form but of opposite curvature or direction; these two curved connections being
so arranged in relation to each other that the curved connection between the down
pipe and the lower junction box acts as a kind of injector, the jet passing through
n

page_text: it into the junction box, causing a suction through the other curved connection in
a direction away from the blow off pipe, which suction tends to prevent the water
in the sections from forcing its way through the back pressure valves down into
tbe blow off pipe and thence short circuiting to the feed outlet. The end of the
down pipe, that acts as an injector, may be contracted or otherwise shaped in any
suitable way to secure the required velocity of the jet of water entering the
junction box.
The above described injector arrangements may in some cases be used without
the back pressure valves.
I also apply to the junction box of the first section of pipes, at the point where
the feed water is first admitted, a similar injection arrangement but preferably
adapted, by means of a suitable nozzle, to produce a stronger suction from the
blow off pipe than the injector arrangements applied to the other sections, so as to
return, through the first section of pipes, any water that may find its way from
any of the other sections into the blow off pipe, and thus prevent such water from
finding its way to the section nearest the outlet to the boiler. In this case also
the back pressure valve between the junction box and the blow off pipe may be
omitted.
Dated this 18th day of September 1903
J. G. CALVERT,
Per W. H. Beck,
115, Cannon Street, London, Agent.
COMPLETE SPECIFICATION.
Improvements in Fuel Economisers or Feed-water Heaters,
applicable also to Tubulous Boilers.
I, JAMES GARDNER CALVERT, of 19 Kyrkogatan, Gothenburg, in the Kingdom
of Sweden, Engineer, do hereby declare the nature of this invention and in what
manner the same 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, feed-water
heater, or tubulous boiler which consists of a number of vertical, or more or less
inclined, pipes arranged in series or sections, the upper ends of the pipes forming
each section being connected to an upper junction box, and the lower ends of the
pipes forming each sectiou being connected to a lower junction box which latter is
in communication with the blow-off' pipe.
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 cach 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 leed water, or part of it, to short-circuit, so to speak, through
the blow-off pipe, more less directly to the outlet pipe leading to the boiler.
In the Complete Specification of a Patent granted to me, dated the 4th March
1893 No. 4775, 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

page_text: themselves, 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 in the Complete Specification of an application for a Patent
No. 7120 dated the 6th April 1893 I have described certain further improvements
for the same purpose which cousist in so constructing 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.
My present invention relates to a further improvement in fuel economisers,
feed-water heaters, or tubulous boilers, constructed in accordance with the above
mentioned Specifications, and the said improvement consists in applying to the
junction box of the first section of pipes, at the point where the feed water is first
admitted, an improved injector or ejector arrangement somewhat similar to that
described in the aforesaid Specification No. 7120, but preferably adapted by means
of a suitable nozzle to produce a stronger suction from the blow-off pipe than the
injector or ejector arrangements applied to the other sections, so as to return,
through the first section of pipes, any water that may find its way from any of the
other sections into the blow-off pipe, and thus prevent such water from finding its
way to the section nearest the outlet to the boiler. In this case the back pressure
valves between the other junction boxes and the blow-off pipe, as described in the
aforesaid Specification No. 4775, may be employed or not as may be preferred.
And in order that the said invention may be fully understood; I will proceed to
describe the same with the aid of the accompanying sheet of drawings, in which
Figure 1 is a sectional elevation of part of a lower junction box with the
aforesaid improved injector arrangement applied thereto.
Figure 1 an elevation of same showing also the lower ends of some of the
heating pipes connected to the said junction box,
Figure 2 an elevation on line X-X looking from left to right in Figure 1, and
Figure 3 an elevation on line Y-Y looking from right to left in Figure 1.
L represents part of the first lower junction box, J the lower ends of some of
the heating pipes connected to the said junction box, D the blow-off pipe, D* the
casting forming the body of the injector, K* the passage or throat leading from
the said injector body to the junction box L, D** the passage leading from the
blow-off pipe D into the body of the injector, and K** a contracted nozzle which
directs the feed water entering by the pipe M through the throat K* into
the junction box. The contracted nozzle K** causes the feed water to enter the
junction box at considerable velocity and tends to create a suction in the
passage D** in a direction away from the blow-off pipe D thus drawing from this
pipe any water that may find its way from any of the other sections into it, thus
preventing such water from finding its way along the blow-off pipe to the section
nearest the outlet to the boiler; and when desired this apparatus may be arranged
to draw a certain amount of hot water from the other sections through the back
pressure valves referred to in the above mentioned Specification No. 4775 when
such valves are employed and to return such water along with the feed water to
the first section when it is desired to raise the temperature of the feed water before
it comes in contact with any of the pipes of the economiser.
In the above description the improved injection apparatus is referred to as
applied to the first lower junction box, and as operating with the feed water on its
first entry into the economiser; but similar apparatus may be applied to any or all
of the lower junction boxes of the economiser, but in that case instead of the feed-
water pipe M being connected to the wide end of the nozzle K** the return pipe,

page_text: such as K¹ for example (shown in dotted lines in Fig. 1) leading the circulating
water from the preceding section of pipes or tubes, is connected thereto, and similar
effects will thereby be produced, that is to say the circulation of water through the
section to which such apparatus is attached will be accelerated, and heated water
that may have found its way into the blow-off pipe will be drawn out therefrom
and forced through the section.
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, so constructed
and arranged that the water is caused to flow successively through all the sections
of pipes or tubes, an injector or ejector device having a branch or passage K×
connected with the junction box, a branch or passage D** connected with the
blow-off pipe and a nozzle K** connected with the feed water inlet pipe, or with
the return pipe from the preceding section of heating pipes, as the case may be,
substantially as described with reference to the accompanying drawings.
Second. 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, constructed substantially as herein described, with the feed water
inlet pipe, or with the return pipe from the preceding section of heating pipes, as
the case may be, the blow-off pipe and the junction box, substantially as described
and for the purposes specified.
Dated this 16th day of June 1903
J. G. CALVERT,
Per W. H. Beck,
115, Cannon Street, London, Agent.