Year: 1886

page_text: Date of Application, 22nd Nov., 1886.
Complete Left, 20th Aug., 1887.
Complete Accepted, 7th Oct., 1887.
We WILLIAM HARGREAVES and WILLIAM INGLIS of the Soho Iron Works, Bolton
in the County of Lancaster, Engineers, do hereby declare the nature of this Invention
to be as follows that is to say :-
This Invention has for its object to improve the mode of constructing, combining
or arranging the parts of cold-air machines, or apparatus for mechanically refrigerating
or cooling air to be used for preserving meat or for other purposes.
Apparatus of the kind to which the present Invention is applicable comprises
one or more cylinders for compressing the air, and one or more cylinders in
which the air, after being compressed and cooled to a certain extent is made to
reexpand and in doing so to return a large part of the power used in compressing
it. Generally in cold-air machines, at present in use, the compresser cylinders and
the reexpander cylinders are directly combined with steam cylinders to supply the
requisite motive power, and with crank shafts; or a crank shaft connected to
the compresser and reexpander piston rods, is driven by means of belts or
toothed gearing from a steam engine or other motor at a greater or less distance.
According to the present Invention however the motive power is not applied in the
manner referred to, but is communicated to what may be termed the main cold-air
machine comprising one or more compresser cylinders and one or more reexpander
cylinders together with water pumps, heat exchanger, and other minor accessories, by
means of compressed air led to the main cold-air machine by a pipe from any con-
venient distance. This motive air as it may be termed and which may be compressed
by a steam engine or other convenient motor, is led into the compresser cylinder or
cylinders of the main cold-air machine, and is therein additionally compressed by the
power returned by means of the reexpander cylinder or cylinders.
When the improved arrangement or combination of apparatus is adopted in a
steamship, for example, the air may be primarily compressed by apparatus, in the
engine room and worked by the main engines or by a separate engine, whilst the
main cold-air machine may be placed near the cold chamber or hold, without having
in the same compartment the inconvenience of hot steam pipes and steam cylinders,

page_text: and without its being necessary to lead a steam pipe through cargo spaces or other
parts of the ship. On land the primarily compressed or motive air may be supplied
from a central station through pipes to two or more cold-air or other machines.
In many cases the air passed through the primary compressing apparatus may be
withdrawn from the cold chamber; but where such arrangement is not convenient,
the fresh air passed through the primary compressing apparatus should if possible
be passed before it is reexpanded through heat-exchanging apparatus in which it can
be cooled by the waste cold air from the cold chamber.
When the air is made to circulate repeatedly through the cold chamber and through
the cold-air machine, a fan or other suitable blowing apparatus is arranged to
withdraw the air from the cold chamber and propel it either directly or through
heat-exchanging apparatus to the machine. This improvement which is applicable
to cold-air machines of the kind at present in use as well as to the improved
arrangement hereinbefore described, causes the air to be withdrawn from the cold
chamber in a more uniform and effective manner, and to be more effectively filled
into the compresser cylinder or cylinders.
In what is hereinbefore referred to as the main cold-air machine, the valve or
valves of the reexpander cylinder or cylinders may be worked, in the ordinary way,
by means of a crank shaft; by a further part of the present Invention, however,
a crank shaft is dispensed with and valve-working mechanism is employed of any
suitable kind such as is used in connection with non-rotative direct-acting steam
pumps. In a similar way valve-working mechanism of the kind referred to, may
also be used when the cold-air machine comprises one or more steam cylinders, the
usual crank shaft being dispensed with and the machine as a whole being much
simplified.
Dated third
1
1000
EDMUND HUNT,
Applicants' Agent.

page_text: Improvements in Mechanical Refrigerating or Cold-air Machines.
We, WILLIAM HARGREAVES, and WILLIAM INGLIS, of the Soho Iron Works, Bolton,
in the County of Lancaster, Engineers, 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, that
to say:―
This Invention has for its object to improve the mode of constructing, combining,
or arranging the parts of cold-air machines, or apparatus for mechanically refrige-
rating or cooling air, to be used for preserving meat or for other purposes.
"
Apparatus of the kind to which the present Invention is applicable comprises one or
more cylinders for compressing the air, and one or more cylinders in which the air,
after being compressed and cooled to a certain extent, is made to reexpand and in
doing so to return a large part of the power used in compressing it. Generally, in
cold-air machines at present in use, the compressing cylinders are directly combined
with steam cylinders to supply the requisite motive power, and with crank shaft ; or
a crank shaft connected to the compressing and reexpanding piston rods, is driven by
means of belts or toothed gearing from a steam engine or other motor at a greater or
less distance. According to the present Invention, however, the motive power is not
applied in the manner referred to, but is communicated to what may be termed the
main cold-air machine comprising one or more compressing cylinders and one or more
reexpanding cylinders, together with water pumps, heat exchanger, and other minor
accessories, by means of compressed air led to the main cold-air machine by a pipe
from any convenient distance. This motive air, as it may be termed, and which may
be compressed by a steam engine or other convenient motor, is led into the com-
pressing cylinder or cylinders of the main cold-air machine, and is therein
additionally compressed by the power returned by means of the reexpanding cylinder
or cylinders. The degree of compression to be given in the distant compressing
cylinder or cylinders worked by the steam engine or other motor, is thus considerably
less than that to which the air is brought on being additionally compressed in the main
cold-air machine. This feature is important and practically advantageous; and it
distinguishes this part of our Invention from arrangements and modes of operation
which have been proposed before the date of the application for Letters Patent to which
the present specification relates.
When the improved arrangement or combination of apparatus is adopted in a
steamship, for example, the air may be primarily compressed by apparatus in the
engine-room, and worked by the main engines or by a separate engine, whilst the main
cold-air machine may be placed near the cold chamber or hold without having in the
same compartment the inconvenience of hot steam pipes and steam cylinders, and
without its being necessary to lead a steam pipe through cargo spaces or other parts
of the ship. On land the primarily compressed air or motive air may be supplied
from a central station through pipes to two or more cold-air or other machines.
In many cases the air passed through the primary compressing apparatus may be
withdrawn from the cold chamber; but where such arrangement is not convenient,

page_text: the fresh air passed through the primary compressing apparatus should, if possible,
be passed, before it is reexpanded, through heat-exchanging apparatus in which it can
be cooled by the waste cold air from the cold chamber.
When the same air is made to circulate repeatedly through the cold chamber and
through the cold-air machine, a fan or other suitable blowing apparatus is arranged to
withdraw the air from the cold chamber and propel it, either directly or through heat-
exchanging apparatus to the machine. This improvement which is applicable to
cold-air machines of the kind at present in use as well as to the improved arrangement
herein described, causes the air to be withdrawn from the cold chamber in a more
uniform and effective manner, and to be more effectively filled into the compressing
cylinder or cylinders.
In what is hereinbefore referred to as the main cold-air machine, the valve or valves
of the reexpanding cylinder or cylinders may be worked in the ordinary way by means
of a cranked shaft; by a further part of the present Invention, however, a crank shaft
is dispensed with, and valve-working mechanism is employed of any suitable kind such
as is used in connection with non-rotative direct-acting steam pumps. In a similar
way valve-working mechanism of the kind referred to may also be used when the
cold-air machine comprises one or more steam cylinders, the usual crank shaft being
dispensed with and the machine as a whole being much simplified.
And in order that our said Invention and the manner of performing the same may
be properly understood we hereunto append four sheets of explanatory drawings to be
hereinafter referred to and representing the principal parts and arrangements of our
improved apparatus. In these drawings the same reference letters and numerals are
used to mark the same or like parts wherever they are repeated.
Figures, 1, and 2, on sheet, 1, of the accompanying drawings are a sectional plan
and a sectional elevation showing an arrangement of our improved apparatus as
fitted in a steamship. A separate compressing engine or machine, M, is placed in the
engine room, E, and from this machine, M, the compressed air, herein termed the
motive air, is led by a pipe, 7, to the compressing cylinder, C, of the main cold-air
machine, A. This cold-air machine is represented as comprising a single compressing
cylinder, C, and a single reexpanding cylinder, X; but there may of course be two or
more of either or both these cylinders. The parts are shown as carried on a box
bed-frame, B, which may be fitted internally as a heat exchanger. The motive air
previously compressed in the machine, M, to a certain degree considerably less than
the maximum is additionally compressed in the cylinder, C, of the cold-air machine, A,
and thereby attains the maximum degree of compression. In its thus fully compressed
state the air next passes into the heat exchanger, B, wherein it is cooled; and thence
proceeds to the reexpansion cylinder, X, wherein the pressure it has attained by the
two successive stages of compression it has undergone, operates to yield power for
working the compressing cylinder, C, also for working the water pumps and other
parts. The air after reexpansion in the cylinder, ✗, and having its temperature
considerably reduced in consequence of its yielding power whilst expanding as is now
well understood, is led into the cold room or rooms, R, in the usual way. The cold-air
machine, A, is shown as comprising a crank shaft, S, with fly wheels, from which shaft
the distribution valve or valves of the reexpansion cylinder, X, may be worked in any
suitable known manner. A compensating arrangement, P, is also indicated at the end
of the machine opposite to that where the crank shaft, S, is placed. This com-
pensating arrangement, P, is of a kind more fully shown in figures, 4, and 5, and
hereinafter explained; and is such as to admit of flywheels being dispensed with or
of smaller flywheels being used than would be otherwise required, as for example when
a crank shaft is used for working the valves.
Figure, 3, on sheet, 2, of the drawings represents in sectional plan an arrangement
suitable for cold-air stores on land, and shows the application of a fan, F, for with-
drawing the return air from the cold room, R, and propelling it through the heat
exchanger, B', thereby insuring its moving uniformly and properly filling the com-
pressing cylinder, C, as hereinbefore explained. The fan, F, is here shown as applied
in connection with a cold-air machine, A, comprising no other new parts and which is

page_text: driven by the crank shaft, S, of a steam engine, T; and the fan, F, is driven by belt
and pulley gearing, G, from the crank shaft, S. We are aware that it has been
proposed to use a fan for propelling the cold air into various parts of the cold room
for the purpose of producing circulation throughout the room, but we apply the fan in
a manner and for a purpose which are obviously different. The application of a
withdrawing fan or blower may be advantageously made in connection with our
improved cold-air apparatus and also in connection with other kinds of cold-air
apparatus.
Figures, 4, and 5, on sheet, 3, of the drawings are a plan and side elevation
representing a cold-air machine made according to our Invention and without crank
shaft or flywheels which are objectionable on board ship. The machine comprises two
compressing cylinders, C, and two reexpansion cylinders, X, the air entering the
compressing cylinders, C, having been partly compressed by a machine (M) at a
greater or less distance. The valve gear which is not fully shown in the drawings
may be such as is used with pairs of non-rotative direct-acting steam pumps, the valve
or valves of one cylinder being worked by the piston rod of the other cylinder. Or
any other suitable non-rotative valve gear may be used. In order to satisfactorily
dispense with a flywheel and crank shaft a compensating arrangement is adopted but
in respect of which we make no claim excepting as combined with other parts in the
manner herein described. Each piston rod, 8, has fixed to it a slide block, 9, working
in guides in the framing, and having jointed to it the piston rods, 10, of two oscillating
cylinders, P, mounted in trunnion bearings in the framing. In the inner ends of these
oscillating cylinders, P, that is the ends furthest from the slide block, air is confined,
and any desired pressure may be maintained therein by connecting their interiors
through their trunnions with a reservoir and pump. When the slide block, 9, is at
the middle of the stroke the oscillating cylinders, P, have their axes at right angles to
the piston rod, 8, and the air in them is compressed to its greatest degree their pistons
being then at the inner ends of their strokes; but as the slide block, 9, moves towards
either end of its stroke the pistons of the oscillating cylinders, P, are drawn out (as
shown in figure 5). At the beginning of a stroke the pressure acting in a reexpansion
cylinder, X, is at its greatest whilst the air in the compressing cylinder is at its least
effective resisting pressure, but during the stroke the conditions vary and become
reversed towards the end of the stroke. The oscillating cylinders, P, compensate
to a considerable extent for the unequal action during the stroke, as a part of the
power acting in the reexpansion cylinder, X, during the first half of the stroke
takes effect in forcing in the pistons and compressing the air in the oscillating
cylinders, P, and the thus compressed air reacting like a spring during the second
half of the stroke yields back power in aid of the reexpansion piston just as the air
pressure acting on it becomes diminished. Instead of both the cylinders, X, being
reexpansion cylinders, one of them may be a steam engine cylinder as in some existing
cold-air machines; but when using a steam engine cylinder in that way we prefer to
proportion and arrange the parts so that the steam cylinder compresses the air in one
compressing cylinder, C, only to a pressure considerably below the intended full
pressure; and so that the thus partially compressed air next passes into the other
compressing cylinder, C, in which it is additionally compressed.
Figure, 6, on sheet, 4, of the drawings is a side elevation of a single tandem
arrangement without crank shaft or flywheel. In this arrangement there are two
steam cylinders, T 1, T2, made of different sizes and provided with suitable valve gear
(not shown) for working on the compound system. There is one compressing
cylinder, C, and one reexpansion cylinder, X; and a pair of oscillating compensating
cylinders, P, are applied to render the action of the machine such as to allow of a
flywheel being satisfactorily dispensed with.
In any case in which it may be considered more convenient the first compression of
the air may be effected in the compressing cylinder or cylinders directly worked by
the reexpanding cylinder or cylinders, the additional compression being subsequently
effected in separate apparatus at a greater or less distance from the main cold-air
machine.

page_text: Having now particularly described and ascertained the nature of our said Invention
and in what manner the same is to be performed we declare that what we claim is :-
1-In a cold-air machine, or in connection therewith, arranging the apparatus to
compress the air at two stages, one stage of compression being effected in the machine
and the other in separate apparatus prior to reexpanding the air, substantially as
hereinbefore described.
2-In a cold-air machine using as a motive agent air compressed in separate
apparatus at a greater or less distance and additionally compressed in the cold-air
machine before yielding its motive force substantially as hereinbefore described.
3-In cold-air apparatus in which the same air circulates repeatedly through a cold
room and a cold-air machine, arranging a fan or other blowing apparatus to withdraw
the air from the cold room and propel it either directly or through heat exchanging
apparatus into the compressing cylinder substantially as hereinbefore described.
4-Constructing a cold-air machine without a crank shaft or flywheel, and providing
for these parts being satisfactorily dispensed with by arranging the other parts and
applying compensating apparatus substantially in the manner hereinbefore described.
Dated this Nineteenth day of August 1887.
EDMUND HUNT,
Applicants' Agent.