Method of and Apparatus for Producing Mixture of _Steam and Air Under Pressure for use in Motive Power Engines.
Year: 1890

page_text: Date of Application, 21st Mar., 1890
Complete Specification Left, 17th Jan., 1891-Accepted, 21st Mar., 1891
PROVISIONAL SPECIFICATION.
Method of and Apparatus for Producing Mixture of _Steam and Air
Under Pressure for use in Motive Power Engines.
I, EDWARD FIELD, of Chandos Chambers, 22, Buckingham Street, Adelphi,
in the County of London, Consulting Engineer, do hereby declare the nature of
this invention to be as follows:-
This invention has reference to a method of and apparatus for producing mixture
of steam and hot air, under pressure for use as motive fluid in engines.
For this purpose the air at a suitable temperature and pressure and the steam are
conveyed through separate passages to a mixing apparatus whence the mixture
passes to the slide jacket or distributing valve chamber (hereinafter called the slide
jacket) of the engine. The mixing apparatus is fitted with differential self-acting
valves the arrangement being such that when the valve controlling the passage of
heated air (hereinafter called the air valve) is opened by the pressure of the hot
air, the valve controlling the passage of steam is also opened and when the air
valve is closed by the combined pressure of the mixture of hot air on the air valve
It is
and the steam acting on the steam valve, the steam valve will also be closed.
the mixture of air and steam thus obtained that passes (through a suitable pipe or
chamber) to the slide jacket of the engine to do work in the ordinary manner.
is desirable that the engine cylinder should be jacketted.
It
Mechanical means might be employed to operate the above described arrange-
ment of valves but I consider this unnecessary and undesirable.
When air is to be mixed with steam according to this invention, I proceed as
follows:-
The air in a dry state is compressed to the required working pressure and then
passed in a compressed state through any suitable form of heater placed in the flue
or flues of a boiler, or in any other suitable position where it will receive sufficient
waste heat, from any source, to raise the air under pressure, passing through the
heater, to a temperature of 400° Fahr. or thereabouts, thus causing considerable
increase in the volume, or pressure of the air. The hot air, and dry steam, the
latter at a somewhat greater pressure, are then conducted through well protected
mains, to a mixing apparatus fitted with differential self-acting valves one form of
which may comprise two valves, one for the hot air and one for the steam both
fixed on one stem so that when one valve is opened or closed, the other must follow
suit. These valves are not of the same size, that for the steam being of con-
siderably less area than that for the air, in the proportion for example of say 1 : 4,
more or less, according to the difference between the average pressures at which
it may be intended to work.
The steam and air are kept separate until they pass into the mixing apparatus.
An arrangement for this purpose is to fit the mixing apparatus with a nozzle
similar to that of an injector the steam passing as a jet through the central passage
and the heated and compressed air through the surrounding annular passages; or
as an alternative which however I consider less desirable the steam might go
through the annular passage and the heated and compressed air as a jet through
the central passage.
In either case as will be understood the object is to keep the
hot air under pressure dry, and separate from the steam until after the passage
of the point of mixture. This operation may be effected by two valves or slides
actuated independently at the proper times by any well known means, but the
arrangement described is preferable as already stated, being entirely self-acting

page_text: and also acting immediately on any reduction of pressure taking place in the slide
jacket of the engine. To reduce the speed of the engine it is only necessary to
throttle the steam passing to the mixing apparatus.
Dated this 20th day of March 1890.
W. LLOYD WISE.
COMPLETE SPECIFICATION.
Method of and Apparatus for Producing Mixture of Steam and Air
Under Pressure for use in Motive Power Engines.
1, Edward FieLD, of Chandos Chambers, 22, Buckingham Street, Adelphi,
in the County of London, Consulting 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:-
In the Specification of my former Patent No. 1997 A.D. 1889 1 described a
mode of mixing heated air and steam and using the mixture in a motive power
engine, and my present invention relates to further improvements consisting in
another method of and apparatus for producing mixture of steam and hot air, for
use as motive fluid in engines.
In carrying out this invention air is mixed with steam as follows:-
The air (which it is desirable should be free from any excess of moisture) is
compressed to a pressure equal or thereabout to the intended working pressure of
the motive fluid in the engine then the air thus compressed is passed alone, through
any suitable form of heater placed in the flue or flues of a boiler, or in any other
convenient position where it will receive suflicient heat, from any source, to raise
the air under pressure passing through the heater to a temperature of say
from 400° to 500° Fahr. or thereabouts, thus causing considerable increase in the
volume or pressure of the air. Steam is supplied from a boiler or generator and
it and the compressed air are conducted simultaneously but separately through
well protected mains to a mixing apparatus hereinafter called a mixer, in which
they are mixed. The steam is by preference supplied at a somewhat greater
pressure than the compressed air. The mixture is conveyed from the mixer to the
slide or valve jacket or casing of the motor in which it is to do work.
The manner in which my invention may be advantageously carried into effect.
will be understood by referring to the accompanying illustrative drawings.
Fig. 1 illustrates partly in elevation and partly in vertical section the application
of my invention to a motive power engine.
1 is a motive power engine; it is shown as of a well known horizontal single
cylinder type but various other types might be used, whether simple or compound.
Usually it will be advantageous to adopt the compound type, it is also desirable
that the cylinder or cylinders and slide or valve jacket or jackets should be steam
jacketed. The water from such steam jackets may be returned to the boiler in any
known or suitable manner. 2 is a steam boiler; it is represented as of the ordinary
Cornish type but might be of almost any other kind. 3 is an air compressor; it
should be of good construction capable of compressing atmospheric air to the
working pressure required by the motor. As represented this compressor is
arranged to be driven directly, but in many cases it will be better to drive the
compressor by a separate crank, so that its action may be correctly timed.
Assuming the working pressure to be 60 lbs. per square inch, the capacity of the
compressor, may be the same as that of the motor cylinder. In some cases the
compressor may be made of a variable capacity or it may be caused to make a
larger or a smaller number of strokes within a given time than the engine, as
may be found convenient. 4 is a heater having sufficient surface exposed to the
action of the hot products of combustion to raise air forced through it to a
suitable temperature say from 400° to 500° Fahr. or thereabout. The heater may

page_text: It is
be of any suitable construction and may be heated from any convenient source.
5 is a pipe for conveying the compressed air from the compressor to the heater.
6 is a well protected pipe for conveying the heated compressed air from the
heater to the mixer. 7 is a mixer of suitable construction, as hereinafter more
particularly explained with reference to the several examples illustrated. 8 is
10 is the starting
the steam main. 9 is the steam admission valve to the mixer.
valve for the motor. 1 is a steam shut-off valve. 12 is a well protected
mixture main for mixed compressed hot air and steam. 13 is the slide jacket of
the motor. 14 is a mixture regulating throttle actuated by governor. The form
of mixer prefer to use is shewn to a larger scale at Fig. 2 Sheet 2.
constructed with differential self-acting valves the arrangement being such that
when the valve controlling the ingress of the heated air (hereinafter called the
hot air valve) is opened by the pressure of the hot air, the valve controlling the
ingress of steam (hereinafter called the steam valve) will also be opened and
when the hot air valve is closed by the conjoint pressure of the mixture of
steam and hot air on the hot air valve, and of the steam acting on the steam
valve, the steam valve will also be closed. 15 is the steam valve having an area
of one.
16 is the hot air valve, having an area of say eight or thereabouts but
the difference will vary according to the difference between the average pressures
at which it may be intended to work. The valve 15 may be made in one piece
with the stem 17 and continued down to the bottom of a socket forming a step
in the upper side of the valve 16 in which it is loosely keyed, the valve 16
having a slight amount of play so that it may readily find its seat care being
taken that when both valves are seated the spindle shall be in contact with the
step in valve 16 at the point 18. 19 is the seat of the steam valve; 20 is the
seat of the hot air valve; 21 is the steam nozzle 22 the hot air passage;
23 the mixture conduit to the engine; 24 the condense water pipe; 25 the steam
inlet from the boiler; 26 the hot air inlet from the heater.
The method of working is as follows:
:-
:
The engine is started with steam only, by opening the valves 10 and 11, the
mixture main 12 and valve 9 being open after a few revolutions the compressor
will have forced sufficient air through the heater to raise the pressure of the air up
to that of the steam; the hot air valve 16 (Fig. 2) will then be lifted by the excess
of air pressure, consequently the steam valve 15 (Fig. 2) will likewise be opened;
hot air and steam will then rush through the mixer forming a volume of mixture
considerably greater in bulk than the mere aggregate of the volumes of the steam
and hot air but at a pressure equal to the mean pressure of the steam and hot air;
the result of this will be that the engine will run faster, for if the volume of
mixture be not used by the engine, an increased pressure of mixture will be the
result; the direct steam communication from the boiler to the engine will then be
closed by the shutting of the valve 10 and the engine will continue running at its
proper normal speed; the steam supply to the mixer, being regulated by a governor
or by any other suitable means at 9 or 14 or the mixture may be regulated by a
valve at 14. Thus as will be readily understood the valve arrangement above
described is entirely self-acting, closing when full pressure has been attained in the
slide jacket, and opening immediately on any reduction of pressure taking place in
the slide jacket of the engine. When the mixture in the mixture main has attained
approximately the same pressure as that of the compressed hot air in the hot air
main, the compound valve will be in equilibrium and both steam and hot air valves
will be closed by the weight of the valves and stem, and will remain so until the
pressure is reduced in the mixture main by the demand of the engine when the hot
air valve will be relieved of some of the pressure on its upper side.
To reduce the speed of the engine it is only necessary to throttle the steam
passing to the mixer at 9. The construction and operation of the mixer may be
variously modified. Thus, instead of the steam passing as a jet through the central
passage or nozzle 21 and the compressed and heated air through the surrounding

page_text: In
annular passage 22 the construction might obviously be so modified that the steam
might go through the annular passage and the compressed and heated air as a jet
through the central passage or nozzle but I prefer the arrangement shewn.
either case, as will be understood, the object is to keep the hot gases of the air
under pressure dry, and separate from the steam, until after the passage of the point
of mixture.
Fig. 3 represents the upper part of a mixer resembling that shewn in Fig. 2 but
adapted to be mechanically moved. For this purpose 3" is a prolongation of the
valve stem, which extends through a stuffing box 19 and by a link 20 is connected
to a suitably operated bell crank 21.
Fig. 4 illustrates a modification wherein slide valves 15" 16" mechanically moved
are used in lien of the self acting lift valves illustrated in Fig. 2. The valve
rods 33 extend through stuffing boxes 19 19" and are connected to suitable
actuating means 21ª.
Fig. 5 shews a self acting lift-valve mixer similar to that shewn in Fig. 2 but
without the steam nozzle 21.
Fig. 6 shows the same adapted to be mechanically moved by the same arrange-
ment as described with reference to Fig. 3.
Fig. 7 shews a modification of self acting mixer in which the steam valve 15
(Figs. 2, 3, 4, 5 and 6) is dispensed with. In lieu of the above described forms of
mixing apparatus there might in some cases be used a mixer such as represented in
several forms respectively in Figs. 8, 9, 10 and 11. In each of these arrangements
6 is the hot air pipe and 8 the steam pipe these being both well lagged or protected,
and of suitable relative cross sectional areas such as eight to one both these pipes
communicate with a common main 12 which I consider it desirable should be steam
jacketed and thus the mixture with the hot air at or approximately at the working
pressure of steam at or approximately at the same pressure, will take place in
suitably regulated proportions as they flow through the main 12 to the slide or valve
jacket of the engine; but I do not consider such an arrangement so advantageous
as that hereinbefore described with reference to Fig. ?.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, declare that what I
claim is :-
:―
1. The production of motive fluid and use thereof in motive power engines
substantially as hereinabove described, namely by compressing atmospheric air then
heating it in a suitable heater and causing it and also steam both being at a suitable
temperature and pressure to enter in regulated proportions, into, and become mixed
in, a suitable pipe or mixer, the mixture thus produced being then conducted to the
slide or valve jacket of the motive power engine and used in the cylinder or cylinders
thereof.
2. The use in connection with motor engines of apparatus such as is herein
described for producing the mixture of heated compressed air and steam, and
supplying it to and for use in, a working cylinder.
3. The use in connection with air heating and compressing apparatus and steam
supply apparatus of a mixer such as is shewn in Figure 2 constructed in the manner
and for the purposes herein described.
D
11 1
2001
W. Lloyd Wise,
EDWARD FIELD.
46, Lincoln's Inn Fields, London, W.C., Agent for the 'Applicant.