Improvements in or connected with Water Tube Steam Generators.
Year: 1895

page_text: Date of Application, 24th Jan., 1895-Accepted, 24th May, 1895
Improvements in or connected with Water Tube Steam Generators.
I, LOUIS MARIE GABRIEL DELAUNAY-BELLEVILLE of 58bs Chaussée D'Antin
Paris in the Republic of France Engineer 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 :-
In steam boilers with water tubes, where the gases rising from the furnace take a
vertical course, such gases reach the chimney as soon as they leave the series of
tubes. Where coal, which gives a long flame is burned, or where the furnaces
are overloaded with fuel, the gases do not burn thoroughly in the series of tubes
but become extinguished on meeting the water tubes and may under certain
circumstances become inflamed again on entering the chimney. Owing to this
fact a considerable proportion of the beat is lost and the gases which happen to
ignite again in the chimney, produce a very high temperature in the latter, which
has a disturbing effect on the proper operation of the chimney itself, while at the
same time exposing the neighbourhood to danger from fire. And this inconvenience
is more particularly fraught with danger on board ships, where it is therefore most
desirable to find an effective remedy for it.
By causing the gases, as they leave the series of steam-generating tubes,
immediately to pass through a feed water heater, they may be prevented from
igniting again, and after traversing the heater, their temperature will be sufficiently
lowered to make it impossible for them to catch fire in the chimney. But on the
other hand the combustion of gases, which are dealt with in this manner, is
incomplete.
But if there be provided, between the steam generating tubes and the feed water
heater, a combustion chamber wherein the combustible elements of the smoke may
mix with the elements causing combustion, at a high temperature, then the gases
will be ignited again and burnt. The resulting heat is utilised in the feed water
heater.
This result is attained with still greater certainty and in a more advantageous
manner by using one common mixing and combustion chamber for two steam
boilers or, two groups of boilers suitably combined together, between which the
feed water heater is located. In this case the gases in excess coming from a
furnace or a series of furnaces which cause combustion, may assist the burning of
the gases in excess capable of undergoing combustion and supplied by the other
series of furnaces, An air blast or steam injector similar to that employed in
connection with the furnaces of the well known Belleville steam generators, may,
moreover, be arranged to effect, in the said chamber, the thorough union of the
various gases meeting therein. By such means the following double result is with
certainty attained; the efficient combustion of the gases and the reduction of the
temperature of the said gases as they enter the chimney. In the case of a single
steam generator deflectors or injectors or both should be arranged at the entrance
of the combustion chamber so as to cause an intimate mixture of the gases.
I will now describe the arrangement which I have devised in order to obtain
these results with reference to the accompanying drawings which illustrate four
marine steam generators arranged in pairs, back to back. Between the two
generators which are set at a suitable distance apart are located the feed water
heaters, one heater being employed for each generator. The respective compart-
ments of the heaters communicate at the top and bottom, while the bases or

page_text: bottoms of the two generators are connected with the chimney by one common-
conduit or flue.
Figure 1 is an elevation, one half of which is drawn in section on line X X,
Figure 2.
Figure 2 is a view one half of which is a plan, while the remaining two quarters
are, respectively, sections on lines Y Y and Y Y¹, Figure 1.
:-
Figure 3 is a vertical section on line Z. Z. Figure 1.
Figure 4 is a vertical section on line U. U. Figure 1.
The following is a description of the several parts of the apparatus, indicating
both their nature and their respective duties, all with reference to the drawings:
A and A' are steam generators of the Belleville type united for purposes of the
circulation of the combustion gases and a aud a' are the steam producing parts of
such generators. B and B are compartments containing the feed water heaters
and and are the elements of the feed water heaters of the Belleville type of
generator.
C and Care smoke flues arranged behind the compartments of the feed water
heaters. A are water tight partitions between the boilers A A'. C is a water
tight partition between the smoke flues C. C'.
D and D are small tubular channels forming dessicators traversed by the steam
as it issues from the boilers and serving to dry the steam.
M and M are gas
combustion chambers, situated at the top of the boilers above the feed water heater
compartments. S and S¹ are air blasts or steam injectors serving to mix the gases
as they meet in the mixing and combustion chamber.
In all other respects the usual arrangement of Belleville steam generators is
retained.
In the case of each generator the feed water is admitted through the graduated
cock E. Figure 1. It is then distributed through the cock of the self moving
column and enters at g into the lower collector or receiver G or G' of the
corresponding water heating series of tubes."
The feed water is distributed throughout the elements b... b of the feed water
heater and rises successively from one tube to the next, being more and more
heated at each stage, until it reaches the upper collecting chamber H or H'.
The pipe conducts the feed water from the collector H to the purifier or I of
the Belleville generator and the said generator operates as though it were fed from
the self-acting cock direct, the column F being in communication with the steam
generating apparatus as usual.
The steam which is generated and which comes out of the purifier I through the
pipe i enters the pipes of the dessiccator D, and issues therefrom through the short
tube or nozzle d by which it is directed towards the engines.
The combustion gases, as they reach the tops of the series of tubes a or a¹ of the
combined boilers A or A¹ pass off into the smoke flues m m of the said boilers and
converge towards the combustion chamber M M. Owing to the speed with which
they move along, these gases, flowing in opposite directions, penetrate each other
and mix, with the result that those of their component elements which are subject
to, and those which cause, combustion (the course of both of which has till then
been parallel) meet and become re-ignited in consequence.
The heat produced by this renewed combustion is taken advantage of in the feed
water heaters.
When the gases have passed beyond the feed water heaters and enter the flues C
or C', their temperature is no longer sufficiently high for them to be again ignited
therein, even though they should have retained any of the combustible elements,
and therefore the drawbacks already mentioned are avoided, while at the same
time the fuel is turned to better account.
Doors O. O are provided in the front part of the series of water heating tubes b
and so that such parts may be readily cleaned within and without, similarly
to what is done as a rule in the steam generating apparatus of the Belleville
generators.

page_text: The doors o, o, situated below the others, serve for the removal of the soot
left behind by the smoke in the ash boxes P and P¹ and are arranged in the same
manner as is usual in steam generators.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, declare that what I
claim is
1. In water tube steam generators of the Belleville type, a gas mixing and
combustion chamber located between the steam generating and water heating
elements, substantially as described and illustrated in the accompanying drawings.
2. In single water tube steam generators a mixing and combustion chamber
located between the steam generating and water heating element, deflectors or
injectors or both being provided at the entrance of the combustion chamber, for
compelling the gases to be thoroughly mixed by changing their direction several
times over and causing them to flow in directions other than parallel so that the
elements subject to combustion come into contact with the elements causing
combustion, substantially as herein before set forth.
Dated this 24th day of January 1895.
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents for the Applicant.