Improvements in or relating to Steam Boiler or similar Furnaces.
Year: 1897

page_text: Date of Application, 4th Aug., 1897-Accepted, 4th Sept., 1897
COMPLETE SPECIFICATION.
Improvements in or relating to Steam Boiler or similar Furnaces.
I, HENRY CROMPTON ASHLIN of 14 Water Street, Liverpool, in the county of
Lancaster 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:―
The object of this invention is to facilitate the insertion or withdrawal of the
furnace tube of a steam boiler or the like.
In carrying out the present invention the upper portion of the back end of the
furnace tube, which fits against the back tube plate, is formed with a flange
perpendicular to the axis of the furnace, the lower portion which extends beyond
the face of the flanged portion is plain or unflanged and the tube end is reduced
in vertical diameter, as compared with the body of the tube by being either
angled up or squared up at the bottom.
In the accompanying drawings:-
Figures 1 and 2 are longitudinal sections of the back and portions of a furnace
tube in position showing alternative forms employed in carrying out the invention,
and
Figure 3 is a longitudinal section illustrating a furnace tube such as is shown
in Figure 1 in course of withdrawal.
Like letters indicate like parts in all drawings.
In Figures 1 and 2 A is a portion of a furnace tube having a flanged upper
portion B rivetted to the back tube plate F of the boiler, and an unflanged
portion C extending beyond the face of the flanged portion. H is the boiler shell
and I the boiler back.
The lower portion of the furnace tube end is set in so that its vertical diameter
is less than the normal diameter of the tube-two methods of doing this are shown
by way of example.
In Figure 1 the lower portion of the end of the furnace tube is angled up or
set in on a slant as shown at D, and rests on and is rivetted to the combustion
chamber plate G, which is flared out with a corresponding slant as at G¹.
In Figure 2 the lower portion of the end of the furnace tube is likewise set in
but so that the projecting portion which is rivetted to the combustion chamber
plate is squared up that is parallel to the axis of the furnace tube as shown at D
Figure 2.
In each case to remove the furnace tube the rivets are knocked out and the
furnace tube drawn through the opening in the front plate of the boiler until
the flanged end engages with the boiler front J or the flange thereof J' as shown
in full lines in Figure 3. The furnace tube can now be tilted up as shown in
dotted lines Figure 3, the reduced or set in portion being capable of passing
through the opening, and the tube may be lowered and drawn out.
To insert a tube the operation is reversed.
The furnace tube may be of any ordinary construction either corrugated, ribbed
or plain, and the front end may be either plain or flanged according to the
construction of the front plate.

page_text: The portions D of the tubes could be made flat, if desired, to bear upon the
parts G or which would be correspondingly flattened to receive them.
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 furnace tube of which the back end has a flanged upper portion, such
as B and a plain or unflanged lower portion such as C continued beyond the face
of the flanged portion, the lower portion of the tube end being set in as at D,
substantially as and for the purpose described and illustrated.
2. A furnace tube having a portion set in as at D and a portion extended as
at C substantially as and for the purpose described and illustrated in the accom-
panying drawings.
3. Setting in the end of a furnace tube as illustrated by way of example at D,
for the purpose of facilitating the insertion or withdrawal of the tube:
4. The combination with a furnace tube of a combustion chamber the bottom
plate of which is set out at an angle as at G¹, but at a distance from F¹ of less
than the normal diameter of the tube, substantially as and for the purpose described
and illustrated in Figure 1 of the accompanying drawings.
5. Facilitating the insertion and withdrawal of a furnace tube in the manner
described.
Dated this 4th day of August 1897
H. C. ASHLIN.
Boult & Wade,
Agents for the Applicant.