Improvements in Steam Superheating Apparatus, also applicable for Heating Air and other Gases or Vapours.
Year: 1890

page_text: Date of Application, 7th Aug., 1890
Complete Specification Left, 18th Apr., 1891-Accepted, 23rd May, 1891
.
PROVISIONAL SPECIFICATION.
Improvements in Steam Superheating Apparatus, also applicable for
Heating Air and other Gases or Vapours.
We, LOUIS CONSTANT UHLER, Engineer, and HENRI EMILE AUGUSTE
DEPRESLE, Engineer, both of No. 12 Rue Caumartin, Paris, France, do hereby
declare the nature of this invention to be as follows:--
In superheating steam it has been customary to place a superheater in the furnace
or in the flues either of each boiler or of one boiler of a series that are being worked
in combination, in order to obtain an effective superheating of the steam by a portion
of the furnace heat. This arrangement has however the disadvantages that firstly
it requires more or less complicated connections of the steam pipes, and secondly
that if the superheater requires inspection or repairs, it necessitates the throwing
out of work of the boiler or set of boilers.
Our present invention has for its object, the construction of a superheater which
shall avoid these disadvantages, and which is for this purpose constructed quite
independent of the boilers and is heated by an independent fire, one such superheater
serving if necessary to superheat the steain from any number of boilers.
For this purpose we construct an upright sheet iron casing, of cylindrical or other
suitable section, resting at bottom on a cast iron base in the centre of which is
provided a furnace grate with ashpit below, while at top the casing is provided with
a central chimney provided with two throttle valves for regulating the draught, one
of these being adjusted for the maximum draught allowed, and then fixed. Within
the casing is formed a brickwork lining, separated from the casing by a layer of
ashes, or other suitable bad conductor of heat.
Within the brick lining are a number of pendant tubes with closed lower ends,
placed in close proximity to each other, and fixed with their upper ends in the
bottom plate of a box-shaped chamber or receptacle situated near the top of the
casing and carried on standards imbedded in the brickwork.
This receptacle is divided by a horizontal partition into an upper and a lower
compartment, and in such partition are fixed a corresponding number of pendant
tubes of sinaller diameter that pass centrally down the outer tubes to near the closed
lower ends thereof, both ends of the inner tubes being open.
The steam from the boiler or boilers being led through branch pipes into the
upper compartment of the receptacle, it flows down the inner tubes to the lower
ends of the outer tubes, and issuing into these, it rises in the annular space between
the two tubes, and being subject during both its downward and its upward travel to
the heat of the flames and combustion gases of the fire, it issues in an effectually
superheated condition into the lower compartment of the receptacle, whence it
passes off by a branch pipe to the place of consumption.
When the superheater is of large dimensions, we prefer to make the receptacle
in two
or more separate parts with external flanges by which they are
bolted together, and in that case we prefer to form spaces between the contiguous
walls of the parts, through which a portion of the combustion gases can pass, so as
more effectually to impart their heat to the steam passing through the receptacle.
Each division of the receptacle is in this case provided with a separate inlet and
outlet branch for the steam.
For ascertaining the degree to which the superheater is heated, an iron tube may
be built horizontally into the casing and brickwork, the inner end being closed
while the outer end is open, so that on looking into the tube it can be seen whether
it is heated to redness.
By arranging on the steam pipes leading to and from the above described

page_text: superheater, a suitable by-pass provided with the necessary shut-off valves, the super-
heater can in case it requires inspection and repairs, be cut off from the steam
supply without interfering either with the steam boilers or with engine or apparatus
which is supplied with steam from them.
The above described superheater may also be employed for heating air or other
gases or vapours. Its construction may also be variously modified; thus it
constructed entirely of brickwork, without the sheet iron-casing.
Dated this 7th day of August 1890.
may
be
ABEL & IMKAY,
Agents for the Applicants.
Improvements in Steam Superheating Apparatus, also applicable for
Heating Air and other Gases or Vapours.
We, LOUIS CONSTANT UHLER, Engineer, and HENRI EMILE AUGUSTE
DEPRESLE, Engineer, both of No. 12 Rue Caumartin, Paris, France, 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 superheating steam it has been customary to place a superheater in the furnace
or in the flues either of each boiler or of one boiler of a series that are being worked
in combination in order to obtain an effective superheating of the steam by a portion
of the furnace heat. This arrangement has however the disadvantages that firstly it
requires more or less complicated connections of the steam pipes, and secondly that
if the superheater requires inspection or repairs, it necessitates the throwing out of
work of the boiler or set of boilers.
Our present invention has for its object, the construction of a superheater which
shall avoid these disadvantages, and which is for this purpose constructed quite
independent of the boilers and is heated by an independent fire, one such superheater
serving if necessary to superheat the steam from any number of boilers.
For this purpose we construct an upright sheet iron casing, of cylindrical or other
suitable section, resting at bottom on a cast iron base in the centre of which is
provided a furnace grate with ashpit below, while at top the casing is provided with
a central chimney provided with two throttle valves for regulating the draught, one
of these being adjusted for the maximum draught allowed, and then fixed. Within
the casing is formed a brickwork lining, separated from the casing by a layer of
ashes, or other suitable bad conductor of heat.
Within the brick lining are a number of pendant tubes with closed lower ends,
placed in close proximity to each other, and fixed on their upper ends in the bottom
plate of a box shaped chamber or receptacle situated near the top of the casing and
carried on standards imbedded in the brickwork.
This receptacle is divided by a horizontal partition into an upper and a lower
compartment, and in such partition are fixed a corresponding number of pendent
tubes of smaller diameter that pass centrally down the outer tubes to near the
closed lower ends thereof, both ends of the inner tubes being open.
The steam from the boiler or boilers being led through branch pipes into the
upper compartment of the receptacle, it flows down the inner tubes to the lower
ends of the outer tubes, and issuing into these, it rises in the annular space between
the two tubes, and being subject during both its downward and its upward travel to
the heat of the flames and combustion gases of the fire, it issues in an effectually
superheated condition into the lower compartment of the receptacle, whence it passes
off by a branch pipe to the place of consumption.
When the superheater is of large dimensions, we prefer to make the receptacle in
two or more separate parts with external flanges by which they are bolted together,

page_text: and in that case we prefer to form spaces between the contiguous walls of the
parts, through which a portion of the combustion gases can pass, so as more
effectually to impart their heat to the steam passing through the receptacle. Each
division of the receptacle is in this case provided with a separate inlet and outlet
branch for the steam.
For ascertaining the degree to which the superheater is heated, an iron tube
may be built horizontally into the casing and brickwork, the inner end being closed
while the outer end is open, so that on looking into the tube it can be seen whether
it is heated to redness.
By arranging on the steam pipes leading to and from the above described super-
heater, a suitable by-pass provided with the necessary shut off valves, the super-
heater can,
in case it requires inspection and repairs, be cut off from the steam
supply without interfering either with the steam boilers or with engine or apparatus
which is supplied with steam from them.
The above described superheater may also be employed for heating air or other
gases or vapours. Its construction may also be variously modified; thus it be
constructed entirely of brick work, without the sheet iron casing.
may
The accompanying drawings shew the construction of a superheater according to
our above described invention.
Fig. shews a vertical section of the superheater, Fig. 2 an elevation, Fig. 3 a
plan, Fig. 4 a plan with the top cover removed, Fig. 5 a cross section below the
pendant tubes, and Fig. 6 a plan of the box-shaped chambers K K secured together
by bolts. Fig. 7 shews an enlarged part sectional view of the chambers K with
pendant tubes.
The apparatus consists of a cast iron base A. to which is fixed a strong sheet iron
casing B closed at its upper end by a cast iron ring with sheet iron cover Con
which is fixed a chimney D. At bottom the casing has an ordinary fire grate E
carried by supports F fixed to the base.
The casing is lined internally with fire brick G and with a layer of cinder H
outside the brick work for preventing loss of heat.
Two throttle valves 11 are provided for regulating the draught; one of these is
permanently fixed in the position to which it has been adjusted, in order that the
fireman may not superheat the steam to an excessive degree.
The hot combustion gases issue round the chamber through passages L Fig. 4
formed in the brick lining. The superheater proper rests upon iron uprights J J
shewn in dotted lines, in Fig. 1, to which the chambers K are attached by means of
lugs S Fig. 6.
The superheater proper consists of a number of pendent outer tubes N of iron or
steel screwed into the chamber K which, for large apparatus is made in two separate
parts, in order to facilitate the manufacture and the convenient handling thereof at
the time of erection, and also to afford a central passage, for the combustion gases,
through a narrow space M formed between the meeting sides of the two parts KK,
which are each divided by a partition O into an upper and lower compartment P
and R.
The outer tubes N are closed at their lower ends either by welding or brazing,
and are screwed into the bottom of the chamber K, so as to communicate with the
lower compartment R. The internal tubes N' of smaller diameter and open at
bottom are screwed into the partition O so as to communicate with the upper com-
partment P.
The steam from the boilers, being admitted into the upper compartments P of
the chambers through branch pipes T, it first descends through the inner tubes Ni
and then ascends in the annular space between the inner and outer tubes, becoming
thereby superheated to the requisite degree, and issues thence into the lower
compartment R, whence it passes through the branch pipes U to the steam engines.
An iron tube V, shewn broken through at V1 in Fig. 1, passes right across the
furnace and is open at the end X, so as to permit of the fireman ascertaining the

page_text: extent of heating at any time by observing whether the interior of the tube is at all
red hot.
The above described superheater with independent heating furnace can be
creci ed and put in action without in any way interfering with the working of the
boilers, the steam of which it is to superheat, nor that of the engines worked
thereby, the main steam pipe being provided with suitable branches provided with
shut off valves or cocks for connecting it to the pipes T and U so that such
connection being established, the steam can at will be passed from the boilers
through the superheater, or this can be cut off and the steam made to pass directly
from the boilers to the steam engines.
The advantages of the above described independent superheater are as follows:-
1. The superheater, being arranged vertically, takes up comparatively little
room on the ground; the pendent tubes being quite free to expand and contract,
they cannot become strained or deformed, even at a very high temperature being
at some distance from the fire, they are not materially attacked thereby; if one or
more tubes require to be replaced this can be effected in a few minutes after the
superheater has sufficiently cooled down, which is of great importance, as all super-
heaters of present construction require considerable time for effecting repairs,
causing the boilers to be thrown out of action for several days.
2. The superheater can be placed near the engine, thus insuring the supply of
superheated steam without loss of heat to the latter, which is impossible with
present constructions with the superheater inside the boiler furnaces, in particular
when there are a number of these.
3. The draught of the superheater furnace being once regulated, the steam will
always be superheated to a uniform degree, which is impossible with existing
arrangements, owing to the irregularity of heating.
4. The erection of the superheater and its connection to the steam pipes can be
effected without any stoppage of the engines, by making the necessary connections
at night or on Sundays.
5. The installation of such a superheater will always be much less expensive
than that of a series of superheaters in connection with the separate boilers of a
group, which require a number of connections that are all the more complicated, the
greater the number of boilers is.
6. The improved superheater can be shifted in position if necessary with very
little trouble and expense, and it may be applied indifferently to any construction of
boiler, which is not the case with other superheaters.
7. The improved superheater can be used for superheating only a portion of the
steam produced by a group of steam boilers, such as that required for the steam
engines, while the remaining steam from the same group of boilers required for other
purposes is led off separately to a common collector.
8. The vertical position of the superheater reduces the deposit of cinders and the
consequent necessary cleaning to a minimum, and greatly facilitates the replacing
of defective tubes.
Although we have described the apparatus as applicable more particularly to the
superheating of steam, it will be obvious that it is equally applicable to the heating
of air or other gases or vapours.
Having now particularly described and ascertained the nature of this inven
tion and in what manner the same is to be performed, we declare that what we
claim is
1. The construction and use of independent superheating apparatus heated by its
own fire, arranged and operating, substantially as herein described.
2. An independent superheating apparatus consisting of the combination of a
casing A. B. C with furnace E and firebrick lining G, a chamber K divided by a
partition into an upper compartment P communicating with the supply pipe T
and a lower compartment communicating with the discharge pipe U, internal

page_text: pendent tubes N₁ fixed to the partition O and communicating with the upper
compartment P, and outer pendent tubes N connected to the bottom of the
chamber K and communicating with the lower compartment R, substantially as
described.
3. In combination with an independent superheating apparatus such as is referred
to in the preceding claims, the use of two throttle valves II in the chimney flue,
one of which is locked in the position to which it is set, and a transverse tube V
situated above the furnace and open at one end for enabling the fireman to observe
the degree of heating, substantially as described.
Dated this 18th day of Anril 1891
ABEL & IMRAY,
Agents for the Applicants.