Improvements in Tubes Applicable to Boilers, Condensers, and the like.
Year: 1886

page_text: Date of Application, 16th Apr., 1886.
Complete Left, 15th Dec., 1886.
Complete Accepted, 18th Jan., 1887.
PROVISIONAL SPECIFICATION.
Improvements in Tubes Applicable to Boilers, Condensers,
and the like.
I CHARLES WICKSTEED of Kettering in the County of Northamptonshire, Engineer,
do hereby declare the nature of this invention to be as follows:-
This invention relates more particularly to the tubes for multitubular boilers
through which the heated gases pass and is designed to obtain a greater amount of
heating surface in the tubes and therefore greater efficiency of boiler without putting
the tubes any closer at the end next the furnace where in well constructed boilers they
are as close together as is consistent with sufficient circulation of water and strength
of tube plate.
To accomplish this I make the tubes tapering and of larger diameter at the smoke
box end than at the fire box end, instead of parallel as is usual, and hexagonal in cross
section instead of round.
Bearing in mind that the further from the furnace the cooler the heated gases are,
and also that the smoke box tube plate need not be of the same strength as the fire
box tube plate, it is evident that the tubes may be gradually enlarged from the fire
box to the smoke box end thus gradually extending the heating surface as the gases
cool, reducing the water space between the tubes, as less is required, and bringing the
tubes closer together in the smoke box tube plate where less strength of metal
between is necessary.
The taper tube may taper either the whole length or any considerable portion of the
length.
This will also obviate the necessity to swell the smoke box end of tubes in order to
facilitate removal.
By employing the hexagonal form I obtain a greater heating surface than would be
possible with round tubes. I also obtain increased circulation and a better scour of
the tubes and the steam has better chance of getting quickly away, because (the tubes
being preferably set with an angle at the bottom) there are no horizontal faces or
I Price 8d l

page_text: approximately horizontal surfaces as there are in round tubes to impede its upward
progress, the angle directing it at once into one or other of the adjacent rising
channels.
I prefer to round the tubes where they go through the tube plate at the fire box or
smaller end and at the smoke box or larger end to retain the flats outside, but make
the tubes round inside to facilitate the fixing.
The construction of the tubes for condensers and for other similar applications other
than steam boilers, is like that already described excepting that it is not necessary to
make the tubes tapering.

page_text: Improvements in Tubes Applicable to Boilers, Condensers,
and the like.
1 CHARLES WICKSTEED of Kettering in the County of Northampton, 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 state-
ment
This invention relates more particularly to the tubes for muliitubular boilers through
which the heated gases pass and is designed to obtain a greater amount of heating
surface in the tubes and therefore greater efficiency of boiler without putting the
tubes any closer at the end next the furnace where in well constructed boilers they are
as close together as is consistent with sufficient circulation of water and strength of
tube plate.
To accomplish this I make the tubes tapering and of larger diameter at the
smoke box end than at the fire box end instead of parallel as is usual and hexagonal in
cross section instead of round.
Bearing in mind that the further from the furnace the cooler the heated gases are
and also that the smoke box tube plate need not be of the same strength as the fire
hox tube plate it is evident that the tubes may be gradually enlarged from the fire box
to the smoke box end thus gradually extending the heating surface as the gases cool
reducing the water space between the tubes as less is required and bringing the tubes
closer together in the smoke box tube plate where less strength of metal between is
necessary.
The taper tube may taper either the whole length or any considerable portion of the
length.
This will also obviate the necessity to swell the smoke box end of tubes in order to
facilitate removal.
By employing the hexagonal form I obtain a greater heating surface than would he
possible with round tubes. I also obtain increased circulation and a better scour of
the tubes and the steam has better chance of getting quickly away, because (the tubes
being preferably set with an angle at the bottom) there are no horizontal faces or
approximately horizontal surfaces as there are in round tubes to impede its upward
progress the angle directing it at once into one or other of the adjacent rising
channels.
I may round the tubes where they go through the tube plate at the fire box or
smaller end and at the smoke box or larger end retain the flats outside, but make the
tubes round inside to facilitate the fixing. Or as it is an advantage to have both ends
round I find the most convenient plan for the large end is to make the diameter of
the round equal to that of the flat of the hexagon reducing the angles to the same
diameter so that as the size of the tube decreases the angles increase until if the taper
be sufficient a complete hexagon is attained at a greater or less distance from the end
of the tube according to the quickness of the taper. The end is quite e reular so as to
fit a circular hole in the tube plate.

page_text: The construction of the tubes for condensers and for other similar applications other
than steam boilers is like that already described excepting that they are preferably
made parallel.
In the accompanying drawings Figure 1 is a longitudinal section with the central
portion removed.
Figure 2 is an elevation of the small or fire box end. Figure 3 is an elevation of
the large or smoke box end end. Figures 4 and 5 are general views of the tube on a
smaller scale:
Figure 4 shows a flat and Figure 5 an angle at the top. Figure 6 is a parallel tube
suitable for condensers and the like.
Figure 7 is an elevation of a tapering tube hexagonal at one end and round at the
other the angles gradually merging into the flats towards the hexagonal end.
A is the central portion of the tube and is of hexagonal form in cross section exter-
nally and by preference internally also. The smaller end B is rounded externally
fitting a round hole in the tube plate in the usual manner; the large end is hexa-
gonal externally but circular inside to facilitate the application of the tube expander.
The length of the portions B and C is intended to be only sufficient for convenient
manipulation in the fixing and fair allowance for repairs and other considerations it
would slightly exceed the thickness of the tube plate at B and would be about 3
inches at in most cases.
It will be understood that the formation of the ends may be altered if desired and
the small end B may be hexagonal both inside and out or outside or inside only and
the interior rounding of C may also be dispensed with if desired or the tube rounded
at Cas at B the outside diameter being preferably equal to the outside corners of the
tube as shown in Figure 6. In the parallel tube Figure 6 the large end C is the same
diameter as that over the angles of the tube and the small end B is equal to the
diameter over the flats of the tube. Or the whole tube may be hexagonal outside and
round inside if preferred.
Having now particularly described and ascertained the nature of my said invention
and in what manner the same is to be performed I declare that what I claim is :-
1. A tube for boilers condensers and the like the exterior of whose walls is
hexagonal in cross-section.
2: A hexagonal tube for boilers condensers and the like having one or both ends
circular substantially as specified and shown in Figure 6 of the accompanying
drawings.
3. A tube for boilers condensers and the like the exterior of whose walls is
hexagonal in cross section in the central portion A and circular at one end B the
other end being circular inside and hexagonal outside substantially as specified and
shown in Figures 1, 2 and 3 of the accompanying drawings.
4. A hexagonal tube for boilers condensers and the like tapering throughout the
whole or the greater portion of its length substantially as specified.
5. A hexagonal tube for boilers condensers and the like whose end is hexagonal out-
side and circular inside substantially as specified.
6. A.tapered tube for boilers condensers and the like in which the diameter of the
round of the large end is equal to that of the flats of the hexagon the angles being
reduced to the same diameter the angles increasing as the size of the tube decreases
until if the taper be sufficient a complete hexagon is attained at a longer or shorter
distance from the end of the tube according to the quickness of the taper substantially
as specified, and shown in Figure 7 of the accompanying drawings.