Improvements in and relating to Multitubular Steam Generators.
Year: 1890

page_text: Date of Application, 15th Oct., 1890
Complete Specification Left, 14th July, 1891-Accepted, 29th Aug., 1891
PROVISIONAL SPECIFICATION.
Improvements in and relating to Multitubular Steam Generators.
I, JAMES NOAH PAXMAN, of the Standard Iron Works, Colchester, in the
County of Essex, Engineer, do hereby declare the nature of this invention to be
as follows:
My invention relates to improvements in the multitubular boiler described in
my prior application for Letters Patent No. 8649 dated the 4th day of June last,
and it consists of certain improvements in the details of construction which render
the boiler a more perfect steam generator.
The general construction of my improved boiler remains as before, that is to
say, it consists of a triple group of tubes inclined with respect to one another, and
having the adjacent ends of the groups of tubes connected together by suitable
collectors, and of a reservoir or receiver fixed between the second and third group
of tubes and provided with the usual steam fittings, the whole being enclosed in a
suitable casing in which is formed a furnace.
"
Instead of letting the water return through the small circulating tubes in the
evaporating or steaming tubes of the lower group, by separating the descending
current from the ascending one by means of a partition dividing the collector into
parts as described in my prior application for Letters Patent, I dispense with these
small circulating tubes and this partition, and arrange for the water to return
through a supplemental pipe or tube, connecting the lower part of the reservoir or
receiver with a mud-collector located below the rear end of the lowest group of
tubes, and provided with suitable blow-off cocks and one or more manholes. The
cooler water from the lower part of the reservoir or receiver passes back to the
mud-collector through this supplemental pipe or tube. This mud-collector
communicates with the collectors at the rear end of the lower group of tubes by
means of bi-conical coupling boxes or their equivalents, the whole being locked
together by bolts which pass right through the collectors and the bi-conical
coupling boxes, and are drawn tight by nuts bearing against suitable bridges placed
in the interior of the mud-collector. In case the mud-collector is too small to
adinit of this arrangement the bolts pass right through the said collector.
After passing through the mud-collector the water ascends through the whole
series of steaming or evaporating tubes and the steam that is formed collects in the
steam reservoir.
This arrangement has the advantage of avoiding the use of collectors having
double chambers, and of having collectors which close the back ends of the tubes
of the lower group, as in my original design.
Instead of the double chambered collectors I use simple collectors communicating
with each other by means of bi-conical or other suitable joints, and instead of the
junction boxes at the rear ends of the tubes of the lower group 1 use single
chambered collectors.
To facilitate cleaning the tubes I form in the exterior wall of each of the
collectors, holes coinciding with the bores of the tubes of each group. These holes
are all of the same size and are provided with coned plugs or plates made of one
size, so as to be interchangeable. These coned plugs are forced against the exterior
walls of the collectors by means of a series of bridges. If the tubes are placed in
groups of three deep, the ends of the bridges are adapted each to bear against the
centre of the top and bottom plug of each group, which are firmly forced home by
the bridge being drawn up tight by means of studs in the face of the collector.
The third or centre plug or plate. is forced home by means of a set-screw threaded
into the centre of the bridge and adapted to impinge on the said plug or plate and

page_text: force it home, a lock nut being provided for fixing the set-screw after the plug is
fixed.
1 sometimes place small metallic diaphragms, or curved deflectors, before the
openings at the upper ends of the tubes of the top group to separate and direct the
water that may be suspended in the steam and so prevent priming. The water so
collected falls to the bottom of the collector and passes through suitable connections
to the reservoir below.
Dated this 15th day of October 1800.
ROBT. ED. PHILLIPS, M.I.M.E.,
Consulting Engineer and Patent Agent,
Royal Courts Chambers, 70-72, Chancery Lane, London, W.C.,
Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in and relating to Multitubular Steam Generators.
I JAMES NOAH PAXMAN of the Standard Iron Works, Colchester, in the
County of Essex, 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:-
My invention relates to improvements in the multitubular boiler described in my
prior Patent No. 8649, dated the 4th of June 1890, and it consists of certain
improvements in the details of construction which render the boiler a more perfect
steam generator.
The general construction of my improved boiler remains as before, that is to
say, it consists of a triple group of tubes inclined with respect to one another, and
having the adjacent ends of the groups of tubes connected together by suitable
collectors, and of a receiver fixed between the second and third group of tubes and
provided with the usual steam fittings, the whole being enclosed in a suitable
casing in which is formed a furnace.
Instead of letting the water return through the small circulating tubes in the
'evaporating or steaming tubes of the lower group, by separating the descending
current from the ascending one by means of a partition dividing the collector into
two parts as described in my prior Patent as aforesaid, I do away with these small
circulating tubes and this partition, and I arrange for the water to return through
one or more exterior pipes or tubes connecting the lower part of the receiver with
a mud-collector or trap located in any suitable position with respect to the lowest
group of tubes, but preferably below the rear end thereof. The cooler water from
the lower part of the receiver passes back to the mud-collector or trap through the
exterior pipes or tubes. This mud-collector or trap is provided with suitable
blow-off cocks, and one or more manholes, and it communicates with the collectors
at the rear end of the lower group of tubes by means of bi-conical coupling boxes
or their equivalents, the whole being locked together by bolts which pass through
the collectors and the bi-conical coupling boxes and are drawn tight by nuts bearing
against suitable bridges placed in the interior of the mud-collector or trap. In
case the mud-collector or trap is too small to admit of this arrangement the bolts
may pass right through the said collector or trap.
After passing through the mud-collector or trap, the water ascends through the
whole series of steaming or evaporating tubes and the steam that is formed collects
in the steam receiver.
This arrangement has the advantage of avoiding the use of collectors having
double chambers, and of having collectors which close the back ends of the tubes
of the lower group, as in my original design.
Instead of the double chainbered collectors, I use simple collectors communicating
with each other by means of bi-conical or other suitable joints, and instead of the

page_text: junction boxes at the rear ends of the tubes of the lower group I use single
chambered collectors.
To facilitate cleaning the tubes I form in the exterior wall of each of the
collectors, holes coinciding with the bores of the tubes of each group. These holes
are all of the same size and are provided with coned plugs or plates made of one
size, so as to be interchangeable. These coned plugs are forced into the holes in
the exterior walls of the collectors by means of a series of bridges. If the tubes
are placed in groups of three, the ends of the bridges are adapted each to bear
against the centre of the top and bottom plug or plate of each group, which are
firmly forced home by the bridge being drawn up tight by means of studs in the
face of the collector. The third or centre plug or plate is forced home by means
of a set screw threaded into the centre of the bridge and adapted to impinge on
the centre of the said plug or plate and force it home, a lock nut being provided if
necessary for fixing the set screw after the plug is fixed.
I sometimes place small metallic diaphragms or deflectors before the openings at
the upper ends of the tubes of the top group, to separate and direct the water that
may be suspended in the steam and so prevent priming. The particles of water so
collected fall to the bottom of the collector and pass into the receiver below,
through the bi-conical coupling boxes.
In the accompanying drawing which illustrates my improved boiler.
Figure 1 is a view in sectional elevation of a multitubular boiler embodying my
improvements and
Figure 2 is a view-on an enlarged scale—in broken sectional elevation showing
the method of closing the holes in the collectors.
Throughout these views similar parts are marked with like reference.
Referring to the drawing, A designates the lower group of tubes. B designates
the intermediate group of tubes and C designates the top group of tubes.
D, D, etc. designate the collectors which in this case are all single chambered ones.
E designates the pipe or tube connecting the receiver with the mud-collector or
trap. F designates the receiver located between the forward ends of the inter-
mediate and top groups of tubes. G designates the steam collecting tube.
H designates the mud-collector or trap located in any suitable position below the
lower group of tubes A. J, J, J, designate the angle irons or battlers resting on
the tubes of each group to direct the passage of the gases or products of combustion,
and K designates the closing plate or partition between the rear ends of the lower
and intermediate groups of tubes.
The exterior pipe or tube E-or pipes if more than one is used-is connected to
the lower part of the receiver F, and to any suitable part of the mud-collector or
trap H, which may be of a cylindrical or any other suitable and convenient shape.
The mud-collector or trap is provided with one or more blow off cocks and man-
holes and it is connected with the collector D at the rear end of the lower group
of tubes A by means of bi-conical coupling boxes d, or their equivalents, the whole
being locked together by bolts L which pass right through the collectors and the
bi-conical coupling boxes and are drawn tight by nuts threaded on the said bolts
and bearing against bridges placed in the interior of the mud-collector or trap H
as illustrated by Figure 1. In case the said collector or trap is too small to admit
of this construction the bolts L are passed right through the collector or trap as
illustrated in Figure 2.
'D', D' etc. designate the coned plugs or plates adapted to close the holes in the
exterior walls of the collectors D. d', d', etc. designate the bridges for keeping the
exterior plugs or plates of each group of three in place. d², d², etc. designate
the bolts by which the said bridges are drawn up and held in position, and d³, d³, etc.
designate the set screws by which the centre plug or plate of each group of three
is forced into and kept in position.
M, M, etc. designate the small metallic diaphragms or deflectors placed before
the opening at the upper ends of the tubes of the group C to collect the small
drops of condensed water which are suspended in the steam in the form of small

page_text: steam vesicles, and allow them to run off into the bottom of the collector and into
the receiver through the bi-conical joints.
The use of a mud-collector or trap placed below the lower group of tubes gives
increased facility for feeding the boiler with water containing a large quantity of
lime, because it provides means for easily and readily removing the deposit.
By making all the plugs or plates and the bridges for closing the holes in the
collectors alike and interchangeable, the erection of the boiler is materially
facilitated. This system is also very convenient for the cleaning out of the boiler
as it allows three tubes to be opened at once by simply unscrewing two nuts on the
bolts holding the bridge.
I wish it to be particularly understood that I do not limit myself to the precise
details of construction or the arrangement of parts hereinbefore described and
illustrated in the accompanying drawing, but that I hold myself at liberty to make
such changes and alterations as fairly fall within the spirit and scope of my
invention.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
1st. The improvements in and relating to multitubular steam generators, as
hereinbefore described and illustrated in the accompanying drawing.
2nd. In a multitubular steam generator of the type hereinbefore described and
illustrated by the accompanying drawing, providing for the return of the water
from the steam receiver to the lower end of the lower group of tubes by means of
one or more exterior pipes or tubes in combination with a mud-collector or trap, as
set forth.
3rd. The combination with a multitubular steam generator of the type described
and claimed in my prior Patent No. 8649 dated the 4th June 1890, of a mud-
collector or trap, constructed, arranged, and operating as and for the purpose
hereinbefore set forth.
4th. In a multitubular steam generator of the type hereinbefore described and
illustrated by the accompanying drawing, attaching the mud-collector or trap to
the collector at the lower end of the lower group of steaming tubes, in the manner
herein before set forth.
5th. In a multitubular steam generator of the type hereinbefore described and
illustrated in the accompanying drawing, closing the holes in the collectors, which
provide for the cleaning of the tubes, by means of interchangeable plugs or plates,
and bridges each adapted to hold three of the said plugs or plates in position, as
set forth.
6th. In a multitubular steam generator of the type hereinbefore described and
illustrated by the accompanying drawing, placing before the forward openings of
the top group of tubes; i.e. the steam drying tubes, small diaphragms or deflectors,
as and for the purpose hereinbefore set forth.
Dated this 14th day of June 1801
ROBT. ED. PHILLIPS, M.I.M.E.,
Consulting Engineer and Patent Agent,
70-72, Chancery Lane, London, W.C., Agent for the Applicant.