An Improved Method of and Apparatus for Generating Steam and Evaporating Liquids.
Year: 1892

page_text: The decision of the Comptroller-General, of the 28th day of March, 1894,
allowed, under Section 18 of the Patents, &c. Act, 1883, an Amendment
of this Specification.
Date of Application, 11th June, 1892-Accepted, 16th July, 1892
COMPLETE SPECIFICATION (AMENDED).
An Improved Method of and Apparatus for Generating Steam and
Evaporating Liquids.
We, HUGH MPHAIL of Stoneleigh Lodge Wakefield in the County of York,
Engineer, and EDWARD SIMPSON and CHARLES HENRY SIMPSON both of Calder
Soap Works Wakefield aforesaid, Soap Manufacturers, 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 :-
i
This invention relates to certain improvements in the method of and apparatus
for generating steam and evaporating liquids, and has for its chief objects the
economical production of dry and superheated steam and the equalization of the
temperature of the top and bottom of the boiler in which the steam is generated
thereby effecting a better circulation. The said improvements also prevent
priming.
For the economical production of power, and for other purposes, dry steam is a
necessity, and various methods have been adopted to ensure a supply of steam in
that state, but these methods are not economical or are otherwise objectionable.
It is also well known that in the various types of boilers used for the generation of
steam, the water at the bottom is colder than that at the top; such difference in
temperature has not only a deleterious effect upon the life of such boilers, but the
safety of the boilers is also endangered thereby; various methods have been
adopted to obviate this serious defect.
According to this invention, the steam generated in the boiler is passed through
the anti-priming pipe or through one or more pipes or tubes to the outside of the
boiler, and is conducted into a suitable superheater or two or more superheaters
placed in the internal flue or flues or in the external flue or flues, or in the combus-
tion chamber, or in such other location where they will be subjected to a much
bigher temperature than that of the steam. The steam is thereby superheated.
It is then conducted by means of pipes, tubes, or coils through the water space of
the boiler where it gives up its surcharged heat. The steam may now be used; or
it may be conducted through another superheater and again passed through the
water space of the boiler before being used. This operation of conducting the
steam through a superheater outside the boiler and then through the water space of
the boiler may be repeated as often as desired. In the case of a Lancashire boiler
for example we prefer that the steam shall be conducted nearly the whole length of
the boiler towards the front end and back again in the water space below the
internal flue, tubes, which is, hitherto, the region of the low temperature of the
boiler. The steam imparts its surcharged heat to the water in the boiler at that
level and thereby facilitates the evaporation of the same, assisting in the equaliza-
ion of the temperature of the boiler, and effecting a more efficient circulation than
hitherto. The steam is then passed outside the boiler and preferably into a second

page_text: superheater, placed, for convenience, alongside the first, and again superheated or
surcharged; it is then passed within the boiler through pipes as before for nearly
the whole length of the boiler and back again in the water space above the internal
flue tubes, thereby further assisting in, or facilitating, the evaporation of the water
and improving the circulation.
The invention comprises various improvements and advantages which we
can more conveniently explain, by means of the accompanying drawings,
wherein :-
-
Figure 1 is a horizontal central section of a Lancashire boiler without the internal
flue tubes.
the
Figure 2 is a similar section showing the two flue tubes in position.
Figure 3 is a longitudinal sectional elevation of the same, shewing the flue tubes,
pipes within the boiler, and the superheaters hereinafter described.
Figure 4 is a section on the line x, x.
Figure 5 is an elevation of the back end of the boiler and superheaters.
Throughout the drawings like letters indicate corresponding parts.
The boiler shewn is of the ordinary well known type of two flued Lancashire.
The mountings and fittings are not shewn as they are all of the ordinary description
and are in no way affected by the adoption of our improvements. It will also be
observed that the adoption of our improvements in no way interferes with efficient
inspection of all the parts of the structure.
The boiler is filled with water to the usual level and steam is raised by firing in
the ordinary manner.
d
Instead, of the steam passing from the boiler through the anti-priming pipe 1,
direct to the stop valve, as hitherto, it is conveyed from the said pipe by means of
pipes a and b into a superheater c placed at the rear end of the boiler in the external
flue where the temperature is much higher than that of the steam within the boiler;
the steam is therein surcharged with heat by the heated gases which impinge upon
the superheater. The steam then passes out of the superheater c, through pipes
and e, into and along the boiler towards the front end and back below the flue
tubes, that is to say, in the coldest part of the boiler and imparts some of the
surcharged heat to the water surrounding the pipes d and e along which latter pipe
the steam returns at the same level to a second superheater f placed alongside the
first named superheater :-The steam is here again surcharged by being subjected
to the higher temperature of the gases. By means of pipe g, the steam is then
again conveyed into the boiler and towards the front, end thereof but this time
above the flue tubes still however below the water level, and is returned towards
the back end by the pipe h. It thus again imparts some of the surcharged heat to
the water through the pipes g and h, thus facilitating the evaporation of the
water.
The pipe his connected to the stop valve. From thence the steam is conveyed
to the engine or is otherwise, used for whatever purpose it is required...
It will be observed that the steam after entering the anti-priming pipe is never
again in contact with the water from which it has been generated, although as
above described it is conducted nearly the length of the boiler four times and is
taken outside the boiler twice, and superheated each time..
It is obvious that we may increase or diminish the number of times the steam
is carried into and out of the generator without departing from our invention.
Moreover instead of using pipes for conducting the steam we may employ boxes,
chambers or coils.
There are several very important advantages as a result of this arrangement,
viz. :—
First. There is no priming.
Priming is a cause of great inconvenience and annoyance to the engineer, as it is
difficult at all times to ascertain its cause and, still more difficult under ordinary
arrangements to prevent its occurrence, and it is generally admitted that priming
accounts for much loss in efficiency in practice.

page_text: Second. The production of dry steam, that is to say, steam from which all
aqueous or watery particles formerly held in suspension have been converted into
steam proper.
Third. The steam passing through the stop valve is superheated or surcharged.
that is to say, the steam in addition to being dry has its temperature raised above
that due to the corresponding pressure of saturated steam.
Fourth. By our improved arrangements we are enabled to materially reduce the
difference between the temperature of the top and bottom of the boiler and thereby
not only facilitate the circulation and evaporation of the water but add to the
longevity and safety of the boiler.
Fifth. The advantages above enumerated together with the quicker production.
of steam are effected much more economically by the consumption of less fuel
than hitherto.
Our improved arrangements can be applied to any boiler, that is to say, it is not
necessary to construct a boiler of a new type in order to carry out our invention.
Not only to Lancashire two flued, but to Cornish, marine, multitubular, locomotive,.
vertical, water tube and other well known types of boilers this our invention can
be applied, and not only for the raising of steam but for the evaporation of liquids
for other purposes.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what.
we claim is :-
1. The method of producing dry and superheated steam, which consists in
passing the steam from a generator through one or more superheaters, placed
outside the generator, and then through pipes, chambers or coils in the water space
of the said generator, or of another generator; substantially as hereinbefore
described.
2. The combination, with a generator, of a superheater, pipes for conducting the
steam to the superheater, and other pipes for conducting the superheated steam
from the superheater through the water space of the same generator, or of another
generator, substantially as described.
Dated this 11th day of June 1892
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicants.