Year: 1886

page_text: Date of Application, 2nd Apr., 1886.
Complete Left, 30th Dec., 1886.
Complete Accepted, 1st Feb., 1887.
I, DAVID CAIRD, of Todbusk, Ulverstone, in the County of Lancaster, Shipbuilder
do hereby declare the nature of my said invention to be as follows:-
My Invention relates to improvements in the construction of fire boxes and flues of
steam generators, and consists in constructing fire boxes and internal flues of steam
generators of solid weldless rings (of iron, steel or other metal used in the construction
of steam generators) corrugated and in two, or more parts and joined together in the
following manner. The solid weldless corrugated rings of which the fire box, or flue
is constructed, are provided and formed with external flanges by which flanges the
series of rings are connected together by rivetting so as to form a fire box, or flue
made up of two, or more rings. A plain metal ring corresponding to the flanges is
placed between the flanges when the joint is made so as to provide caulking edges
inside the fire box, or flue.
For example, in constructing the fire box, or furnace of a steam generator, I form
such fire box of three solid weldless corrugated rings; the centre ring is formed with
an external flange at each end, the outer and inner rings being formed with
corresponding flanges at their inner ends so that the three rings can be joined
together by rivetting, in one length. The combustion chamber end of the ring which
joins the combustion chamber is formed with a semi peripherial external flange on its
upper part, to join the vertical plate of the combustion chamber, and with a plain
continuation on its under portion, to join the shell plates of the combustion chamber.
The outer end of the ring which joins the furnace front plate is made with a plain
continuation to come inside and connect to, a flange on the furnace front plate.
By constructing furnaces and flues of solid weldless rings, corrugated and joined
together in the manner described the external flanges on the rings form a stiffening
to the furnace, or flue, and tend to prevent the collapse of the furnace, or flue, also in
the case of collapse, or damage only the defective portion of the furnace, or flue need
be removed, and renewed.
Fire boxes and flues constructed of solid weldless corrugated metal rings and joined
as above described are alike applicable for marine and land boilers. The solid
weldless corrugated rings being of diameter and number to suit the size of the fire
box, or flue.
וזזז

page_text: COMPLETE SPECIFICATION.
Improvements in the Construction of Fire Boxes and Flues of
Steam Generators.
I, DAVID CAIRD, of Todbusk, Ulverstone, in the County of Lancaster, Shipbuilder,
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:
My Invention relates to the construction of furnaces, fire boxes and flues of steam
generators, and consists in constructing furnaces, fire boxes and internal flues of steam
generators of solid weldless rings, being cylindrical shells (of iron, steel, or other
metal used in the construction of steam generator furnaces) corrugated and joined
together. The solid weldless rings of which the fire box, or flue is constructed are
made from a mass of metal without joint, or weld the corrugations being formed
during the process of rolling, or pressing. The rings are provided with external
flanges preferably formed in their manufacture. The flanges of the rings are
connected together by rivetting so as to form a fire box, or flue made up of two,
three, or more rings. A plain metal ring corresponding to the flanges is preferably
placed between the flanges when the joint is made so as to provide caulking edges
inside the fire box, or flue. The rings or shells may vary from about 2 to 4 feet in
length.
This Invention is applicable to all steam generators employing furnaces of cylin-
drical form, such for instance as those of ordinary Marine, Cornish or Lancashire
types. Some of the advantages attending the construction and use of furnaces
according to this Invention are that by forming the cylindrical shells, or rings from
a mass of metal without joint, or weld and by forming the corrugations during the
process of manufacture, that is to say, during the process of rolling (such as by the
process set forth in the Specification of Letters Patent No. 4288 granted to John
Windle, or pressing, the greatest strength of the material will be obtained. Also it is
inconvenient to manufacture weldless, corrugated cylindrical shells (such as by the
process set forth in the Specification of Letters Patent No. 4288/80 granted to John
Windle) of a greater length than about four feet. Also that the flanges which are
formed with the other portion provide an amount of strength in steam generator
furnaces over that possessed by ordinary corrugated furnaces.
By manufacturing furnaces of steel according to my Invention I avoid heating and
re-heating the metal and subjecting it to repeated effects of heating and cooling.
Ordinary welded corrugated steel furnaces are subjected to these influences. Hence
all the dangers of cracking, or bursting due to local strains, which are frequently set

page_text: up in steel furnaces made of weldless corrugated plates, during, or after manufacture
are obviated. This feature is the result of the cylindrical corrugated shells being
rolled, or pressed directly from a mass of metal without weld, or joint (such as by the
Windle process) they are thus not subjected to the effects of cooling and reheating.
In case of collapse of furnaces of cylindrical form, such as those used in the
Lancashire Cornish and Marine type of steam generators, it is more frequently the
centre portion viz that portion between the front and the combustion chamber, or the
back of the steam generator as the case may be which gives way. Now in case of a
collapse of a furnace constructed according to my Invention and assuming that the
centre portion gave way such portion could be readily removed without interfering
with the end portion. The detaching of the centre ring, or rings is effected by
cutting away the rivetting at the flanges. This facility affords a particular advantage
in that it does not necessitate the taking out of portions more difficult of removal.
This feature is particularly advantageous in the case of marine steam generators such
as the return tubular type set forth with reference to the Drawings.
Furnaces for steam generators of the marine type constructed as herein set forth
hold the further advantage that they can be easily got into, or out of an ordinary ships
stoke hole.
As an example, in constructing the fire box, or furnace of a marine steam generator
of the return tubular type it is preferable to form the fire box, or furnace of three
solid weldless corrugated cylindrical shells, or rings. The centre ring is formed with
an external flange at each end and the outer and inner rings are formed with
corresponding flanges at their inner ends, so that the three rings can be joined
together by rivetting, in one length. The combustion chamber end of the ring which
joins the combustion chamber is formed with a semi peripherical external flange on
its upper part to join the vertical plate of the combustion chamber, and with a plain
continuation on its under portion, to join the shell plates of the combustion chamber.
The outer end of the ring which joins the furnace front plate is made with a plain
continuation to come inside and connect to a flange on the furnace front plate.
In order that my Invention may be clearly understood I have hereunto annexed
two sheets of Drawings illustrative thereof.
Figure 1 is a longitudinal section through a furnace, or flue of a marine steam
generator of the example above specified according to my Invention. This Drawing
shows an example of furnace, or flue of about 6 feet 6 inches long formed of three
weldless corrugated cylinders, or rings A A¹ A'. The outer end of the cylindrical
ring A which joins the furnace front plate B is made with a plain continuation a to
come inside and connect to a flange 6 on the furnace front plate B the inner end of
the cylinder A is provided with an external flange a¹. The centre cylinder A¹ is
formed with an external flange a¹ at each end and the inner cylinder A³ is formed
with an external flange a¹ to join the inner flange a' of the cylinder A¹ and with a
semi peripherical external flange a to join the vertical plate C of the combustion
chamber D and with a plain continuation a³ on its under portion to join the shell
plates E of the combustion chamber D. Between the flanges a¹ of the cylinders A A¹
and A there are provided metal rings e corresponding to the flanges. The
cylinders A A¹ and A' are connected together by rivetting which passes through
the flanges a¹ and rings e respectively as shown. When the joint is made the rings.e
provide caulking edges inside the flue.
Figure 2 is a sectional elevation of a furnace according to my Invention of a
Cornish or Lancashire type of steam generator of about 30 feet long. In this case
the furnace is made up of seven of the flanged cylindrical shells, or rings.
In the Drawing it will be seen that the flanges of the rings, or shells A' are
provided with caulking ring strips e. The end plates of the generator are provided
with internal flanges & and to these flanges the ends a of the end shells, or rings A
and A' are attached.

page_text: 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
"
1st. The improvements in the construction of fire boxes, flues, or furnaces of steam
generators herein described which consist essentially of a fire box, or furnace flue
made up of solid weldless corrugated cylindrical shells connected by flanges
substantially as and for the purposes specified.
2nd. A fire box, or furnace of a steam generator of the marine type constructed
substantially as herein set forth and illustrated in Figure 1 of the Drawings.
3rd. A fire box, or furnace of a steam generator of the Cornish, or Lancashire
type constructed substantially as herein set forth and illustrated in Figure 2 of the
Drawings.