Year: 1888

page_text: Date of Application, 1st Aug., 1888
Complete Specification Left, 4th Apr., 1889
Complete Specification Accepted, 1st June, 1889
Communicated from abroad by ALEXANDER YOUNG, residing at Honolulu,
Island of Oahu, Hawaiian Islands, Engineer.]
on the
I, THEOPHILUS HARRIS DAVIES, of Nos. 49 & 51 The Albany, Old Hall Street,
Liverpool, in the County of Lancaster, Merchant, do hereby declare the nature of this
invention to be as follows:-
The object of my invention is to utilize the heat contained in the gaseous products
of combustion from steam boiler fires, after they have done their usual work and are
on their way to the chimney, for the purpose of superheating exhaust steam or
vapour.
To accomplish this object, I make use of a graduated compound steam boiler
constructed with a number of compartments, in one or more of which is generated
the steam which is used in the high pressure cylinder of a compound engine, or the
first cell of a multiple effect evaporating apparatus, whilst the other compartments
receive and superheat the exhaust steam or vapour from each cylinder or cell in its
passage to the next...
Each of these superheating compartments is provided with large heating surface
acted on by the hot gases which after having done their work in the steam generating
compartment are ordinarily discharged into the air, but which are of higher tempera-
ture than the exhaust steam or vapour which is to be superheated.
The superheating compartments are so arranged that the hottest of the waste gases
act, first, upon the compartment receiving exhaust of highest pressure, thus main-
taining the greatest, practicable, difference of temperature between the superheating
medium, and the steam-or-vapour to be superheated.
The forms and arrangements of graduated boilers for this purpose necessarily vary
according to the particular uses to which they are applied.
For example, when a graduated boiler is applied in connection with a compound
steam engine arranged for triple expansion, one compartment of the boiler has its fire

page_text: box and set of tubes communicating with the chimney, and behind this are situated
two compartments provided with tubes, the one of these for heating the exhaust steam
from the first cylinder before it acts in the second, and the other for heating the exhaust
steam from the second cylinder before it acts in the third. In the uptake to the chimney
is arranged a damper valve, which in one attitude directs the products of combustion
from the front or steam generating compartment up the chimney, and in another
attitude directs them through the tubes of the hinder compartments. A convenient
arrangement is to place two cylindrical steam generating boilers side by side, and
above and between them a tubular boiler divided into compartments, its tubes forming
passage for the products of combustion from the steam generating boilers to the
chimney.
In like manner, when the invention is applied in connection with multiple effect
evaporators, the vapour from the first vessel or pan, instead of passing direct to the
heating coils or jacket of the second, is passed in the first place through a compart-
ment of a graduated boiler to receive heat, from the products of combustion on their
way to the chimney. The vapour from the second vessel or pan is similarly heated
before acting on the third, and so on successively according to the number of vessels
or pans employed.
Instead of thus treating the vapours generated from the successivo vessels, the
steam discharged from the coils or jacket of the first may be heated on its way to the
coils or jacket of the second and so on successively. Or both the vapour generated in
each pan or vessel and the steam discharged from its jacket or coils may be heated by
the products of combustion from the boiler fire and then made to act on the next pan
or vessel in order.

page_text: Improved Means of Generating and Superheating Steam.
I, THEOPHILUS HARRIS DAVIES, of Nos. 49 & 51 The Albany, Old Hall Street,
Liverpool, in the County of Lancaster, Merchant, 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 my invention is to utilize the heat contained in the gaseous products
of combustion from steam boiler fires, after they have done their usual work and are
on their way to the Chimney, for the purpose of superheating exhaust steam or
vapour.
To accomplish this object, I make use of a Graduated Compound Steam Boiler
constructed with a number of compartments, in one or more of which is generated
the steam which is used in the high pressure cylinder of a compound engine, or the
first cell of a multiple effect evaporating apparatus, whilst the other compartments
receive and superheat the exhaust steam or vapor from each cylinder or cell in its
passage to the next.
Each of these superheating compartments is provided with large heating surface
acted on by the hot gases which after having done their work in the steam generating
compartiment are ordinarily discharged into the air, but which are of higher tempera-
ture than the exhaust steam or vapor which is to be superheated.
The superheating compartments are so arranged that the hottest of the waste
gases act. first, upon the compartiment receiving exhaust of highest pressure, thus
maintaining the greatest, practicable, difference of temperature between the super-
heating medium, and the steam or vapour, to be superheated.
Different methods of carrying out my invention are illustrated by the accompanying
drawings.
Fig. 1 is a longitudinal section of my Graduated Compound Steam Boiler, in con-
nection with a triple expansion engine.
Fig. 2 is a transverse section through the steam generating portion A at F. G.
Fig. 1.
Fig. 3 is a transverse section on L......M Fig. 1. through the superheating com-
partments D, and J.
Fig. 4 is a plan of the graduated boiler.
Figs. 5 and 6. show a combination of my exhaust steam superheaters, with a pair
of double ended marine boilers of ordinary type, arranged for use with a compound
engine having one high, and two low pressure cylinders. Fig. 5 is a longitudinal
section of one of the boilers and through the superheaters. Fig. 6. is half an end.
view and half a transverse section on K,.......
Fig. 7 is a plan of the boilers shewn in Figs. 5 and 6.
Figs. 8 and 9 shew a form of my Graduated Compound Steam Boiler, in which
superheaters for the steam and vapor of low pressure are connected to a pair of
ordinary tubular steam boilers this arrangement being applied to a triple effect
vacuum evaporating apparatus such as is commonly used for concentrating liquids.

page_text: Fig. 8 is a plan of this combination.
Fig. 9 is an end view, shewing partly in Section the superheaters and one of the
Boilers.
Referring first to Figs. 1, 2, 3 and 4 the steam boiler A has a compartment, in
which steam is generated in the usual manner. The products of combustion then
pass in contact with the heating surface and through tubes, or other extended
heating surfaces through, or around which, the exhaust steam or vapor, to be super-
heated passes, and is operated on by the heat remaining in the gases, after they have
done their work in the generating compartiment, whence they are usually, discharged
into the chimney.
Examples of the superheating compartments are shown at D and J. Figs. 1 and 3.
A swinging curved plate N. turning on a spindle O. Fig. 1-changes the direction
of the waste gases on their way to the chimney and causes them to flow through the
compartment D. (which may be a twin compartment as shewn in Fig. and from
the Compartment D. through the compartment J. and thence to the chimney. On
turning the swinging plate N. to the position indicated by the dotted lines the gases
escape directly to the Chimney, without passing through the superheating com-
partments D and J. At first starting this is the position of the plate N.; when
steam is raised in A. to the proper pressure for use, the plate N. is turned, so that
the gases are directed through the superheaters to the chimney. The steam from A.
passes to the high pressure cylinder, the exhaust steam from which passes by the
pipe E. to the Superheater D., where-it is superheated by the waste gases having the
highest temperature.
From the superheater D.. the superheated steam passes by the pipe H., to the
second cylinder the exhaust from which passes by the pipe I. to the superheater J,
where it is again superheated by the passage of the gases, on their way to the
chimney and whence it passes by the pipe K. to the low pressure cylinder, from which,
after performing work, it passes to the condenser.
Should the temperature of the superheated exhaust steam be so high as to be
objectionable or should an increase of volume be desirable, a spray of water may be
introduced into the superheaters, or into the pipes conveying the superbeated exhaust
steam from them, for the purpose of reducing the temperature, and increasing the
volume of the superheated exhaust steam. By the arrangement described the hot
gases, which have done duty in generating steam, and which are usually permitted to
escape by the Chimney, are made to act, first, when their temperature is highest upon
the exhaust steam of highest pressure discharged from the high pressure cylinder,
and secondly, when their temperature is thus somewhat reduced upon the exhaust
steam of a lower pressure discharged from the second cylinder obviously such an
arrangement is applicable to any number of cylinders and superheaters maintaining
the greatest practicable difference of temperature, between the heating agent applied
to each superheater, and the exhaust Steam to be superheated in it.
If the waste gases, after passing through the superheater for steam of the lowest
pressure have a temperature too low to secure a good draft, a forced draft may be
used.
Figs. 5, 6 & 7 illustrate a modified arrangement of the apparatus in connection
with a pair of double ended marine boilers, working a compound engine having one
high pressure, and two low pressure cylinders.
In this arrangement A, is a twin exhaust steam superheater, through which the
gases from both ends of the boilers, pass to the chimney, as indicated by the
arrows c, c, c. D, is a passage connecting the two parts of the superheater; G, is
the steam pipe leading to the high pressure cylinder, and E its exhaust pipe leading
to the top of the superheater at H. The exhaust steam passes down through one
compartment of the superheater among its tubes, through the passage D, to the other
compartment rises through its tubes, and goes by the pipe F, to the low pressure
cylinders. I, I, are water spray pipes which can be used to create vapor in the super-
heaters whence any water that accumulates can be drawn off to the hot well. The

page_text: superheaters should be provided with doors for removing any dirt, that may be
deposited in them.
The Graduated Compound Steam Boiler may be used with advantage in evaporating
liquids as illustrated in Figs. 8 and 9 in which it is shown combined with an ordinary
triple effect vacuum evaporator. The exhaust steam from any steam user is super-
heated in compartment (, of the superheater, and passes to the first cell of the
evaporator, where it does duty in boiling the liquid contained in that cell. The vapor
rising from the liquid boiled in the first cell, is superheated in compartment G, of the
superheater, and doos duty in boiling the liquid contained in the second cell. The
vapor rising from the liquid boiled in the second cell, is superheated in compartment J,
of the superheater, and does duty in boiling the liquid contained in the third cell,.
whence it passes to the condenser, and to the vacuum pump in the usual manner.
A, Fig. 9 is the middle cell of the triple effect evaporating apparatus having the
three cells A A A Fig. 8 B, the exhaust steam pipe from the engines, or other
steam users, enters at B' the underside of the compartment C, of the superheater D,
Pipe E, conducts the superheated exhaust steam from the compartment C, to the heating
surface of the first cell A, through valves El.
The vapor rising from the liquid in the cell A111, passes through pipe F, into the
save-all, and through valve F', into the pipe F", which enters the compartment G, of
the superheater, on its under side. The superheated vapor then passes through
pipe H to the second cell A".
The vapor
from the cell A", passes through pipe 1, valve I, and pipe I", and enters
the superheater compartment J, at its top; from J, it passes by the pipe K, to the
cell A¹.
The vapor from the cell A¹ passes through the pipe L, to the save-all M, and on to
the condenser N, and vacuum pump O.
The products of combustion from the two generating boilors A. A. pass through the
smoke boxes into the tubes of the superheating compartments C and G and
return through the tubes of the superheating compartment J, to the smoke box R
and pass thence to the chimney P.
The superheating of different grades of vapor may be continued through any
number of cells and superheaters, or, the exhaust steam from the heating pipes or
drums, of each cell of multiple effect may be re-superheated as many times as there
are cells in the apparatus, by having a sufficient number of compartments in super-
heater for that purpose. Instead of using the vapor from the boiling liquid, the
exhaust from heating pipes or druins, of each cell of the multiple effect. evaporator
might be made to pass through a superheater compartment to the heating surface of
the following cell, and so on throughout all the cells of the apparatus successively
the vapor from the liquid in all the cells, in common, going to the condenser ; in
which case the vacuum in all the cells would be the same.
As an advantage to be derived from my Invention, it may be stated that in
existing compound engines a much earlier cut-off may be adopted in the high
pressure cylinder, because the various grades of exhaust can receive increased heat
and volume, for use in the low pressure cylinders.
For new compound engines a smaller high pressure cylinder can be used for a
given power. Again in vacuum evaporator a large economy of fuel is secured, by
superheating the exhaust steam or vapor at its various pressures.
I do not claim the superheating of steam taken directly from a boiler but only the
superheating of exhaust or spent steam and vapor at various pressures by utilising the
heat remaining in the gases of combustion, after they have done duty in generating
steam, and while they are on their way to the chimney.
Having now particularly described and ascertained the nature of this inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is
1. The herein described method of superheating exhaust steam from the higher
pressure cylinders of compound engines before it enters the lower pressure cylinders

page_text: or superheating the steam or vapour from the cells of multiple effect evaporators
before it enters the next cells in order, utilising for this purpose the heat of combustion
gases on their way to the chimney.
2. For operating in the manner set forth in the preceding claim, the combination
of a series of boiler compartments, in one or more of which steam is generated, and
in the other, or others, of which, exhaust or spent steam or vapor of one pressure, or
of several degrees of pressure, is superheated by the hot gases resulting from the
combustion of fuel in the generating boiler, or boilers, the whole constituting a
graduated boiler arranged and operating substantially as described.
3. The combination of a Graduated Boiler, such as is referred to in the preceding
claim with a compound engine or with a multiple effect evaporating apparatus sub-
stantially as described.