Improvements in Steam Engine Air Pumps.
Year: 1899

page_text: Date of Application, 1st Nov., 1899
Complete Specification Left, 31st July, 1900-Accepted, 22nd Sept., 1900
PROVISIONAL SPECIFICATION.
Improvements in Steam Engine Air Pumps.
I, FRANCIS DRAKE, of 157, Fenchurch Street, London, E.C., Engineer, do
hereby declare the nature of this invention to be as follows:-
My within invention relates more particularly to the class of steam engine
air pumps, which are adapted to be arranged in the interior of screw, or paddle
steamers, and in many cases on land engines, and my object is to provide an
air pump without head, foot, or bucket valves being used in the pump chamber.
The head valves being placed on a division plate, fitted between the water
chamber, and the hotwell, as shown in the accompanying drawings, but the
division plate may be placed in a horizontal position, thereby further reducing
the number of valves to be employed, altho' this is not shown in the drawings.
I so arrange the working of the pump in two ways. (Fig. 1) shows the pump
fitted with an outer water, & air chamber, with a pipe, leading from the bottom of
the pump barrel to the chamber.
The walls of the pump barrel having inlet openings, placed at a convenient
height to admit of an easy flow of water, & air on to the top of the buckets.
The ends of the outer water chamber being closed to the inlet from the con
denser, there being only one inlet opening from the condenser direct to the
bottom of the pump chamber.
(Fig. 2) shows the pump without the use of the water, & air chamber
round the bottom of the pump barrel, the pipe leading direct from the bottom
of the pump to a single inlet opening in the pump chamber, thus having a
free discharge of water on to the top of the bucket, an air vessel being placed
over the inlet, as near the barrel as possible, it being made large enough to
overcome the momentary pressure of water & air, which would be due to the
bucket passing the inlet.
Referring to the accompanying drawings, (Figs. 1 & 2) show the pump without
the use of a head valve plate, or seat, in the barrel, the valves being placed
in a perpendicular division plate between the open top well, round the pump
barrel, and the hotwell, so that in the event of the valves getting out of order,
the cover on top of the hotwell can be removed, and the valves easily repared, or
replaced, with stopping the engines, or causing any loss of vacuum in the
condenser, or loss of fresh water, no doors being required in the pump barrel.
I so arrange, that when the bucket, or plunger is at the end of its downward
stroke, the top edge of the bucket shall not come below the top edge of the inlet
opening from the condenser, thus stopping the flow of water back into the con-
denser, from the top of the bucket.

page_text: I, FRANCIS DRAKE, of 157, Fenchurch Street, London, E.C., 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:-
My invention relates to improvements in steam engine air pumps but more
particularly to that class of steam engine air pumps, which are adapted for use
in connection with marine engines although the same may be used with land
engines, and the object of my said invention is to provide an air pump in which
neither head, foot or bucket valves are employed in the pump chamber. In
carrying my invention into practice, the head valves are arranged on a division
plate, fitted between the water chamber and the hot-well; but if desired the
before mentioned division plate may be arranged in a horizontal position thereby
reducing the number of valves to be employed, but this feature of my invention
I have not illustrated in the drawings.
Reference is to be had to the accompanying drawings which illustrate two
convenient and advantageous forms of carrying out my said invention.
Fig. is a vertical section of a pump constructed in accordance with my
invention, having an upper air chamber, and an upper and lower water chamber
round the pump chamber.
Fig. 2 represents horizontal sections on lines and yy of Fig. 1 respectively.
Fig. 3 represents a vertical section of a modified form of pump, and
Fig. 4 are horizontal sections on lines and of Fig. 3 respectively.
Like letters of reference indicate corresponding parts in the several figures.
Referring first to Figures 1 and 2, A represents the pump chamber and A¹ the
bucket or piston, B the upper water chamber, B the upper air chamber, B2. the
lower water chamber, and C the hot-well, B a pipe leading from the bottom of
the pump chamber to the lower water chamber, A2 openings in the walls of the
pump chamber placed at a convenient height to admit of an easy flow of water
and air on to the top of the bucket, and A³ a single opening at the end of the
pump barrel leading to the condenser E.
These figures illustrate the pump without the use of a head valve plate, or seat
in the pump barrel, the valves B B being arranged upon a perpendicular divis
sion plate D placed between the open top well round the pump
barrel and the hot well, 50 that. in the event of the valves
getting out of order, the cover on the top of the hot-well can easily be removed
and the valves repaired or replaced without stopping the engines or causing any
loss of vacuum in the condenser or loss of fresh water no doors being required in
the pump barrel. The valve B is provided to allow of a free escape of air,
vapour, or water if need be.
The bucket or plunger is so arranged, that at the end of its downward stroke
the top edge of the said bucket or plunger does not pass below the top edge of
the inlet opening from the condenser, thus stopping the flow of water from
the top of the bucket or plunger back into the condenser.
Objection may be raised to the open top water chamber but I provide all round
the top of the said chamber a stepped cover (not shown in the drawings) the
upper step of said cover over-lapping the lower steps alternately, or the said steps
may be cast integral with the chamber thus preventing the water in the chamber
from flapping on the bucket or plunger owing to the rolling of the ship.
By adopting this method of construction an easy cushion is gained both on
the upward and downward stroke of the plunger at the same time the height.

page_text: weight and expense incurred in construction is greatly reduced, and less danger
of the pump or pumps getting out of order.
An overflow valve, may, if necessary be fitted in any convenient position, and
instead of a single pipe B3 one or more pipes may he provided with a two
way cock to distribute the water over the bucket or plunger. Although I have
shewn the bucket as conical in the drawings yet the same may be formed of
rounded or hollow shape to suit requirements if necessary.
Instead of the continuous water chamber round the top of the pump barrel I
may use a pipe fitted to the head of the pump and connected direct to the hot well
in which case it is only necessary to use one valve, the same being so arranged
that it is easy of access without interfering with the running of the engine.
The action of the pump is as follows:-Water and air from the condenser enters
the pump barrel through the inlet A³ and thence passes into the pipe B³, the
plunger A descending, forces the water and air through the said pipe B³ into
the lower water chamber B the further descent of the plunger forces the air and
water through the opening A2 into the pump barrel A and on to the top of the
plunger A, the plunger having reached the end of its downward stroke, the
inlet A is closed by the said plunger thereby preventing the rush of water and
air from passing back into the condenser E.
Referring now to the modification illustrated in Figs. 3 and 4.
These figures shew the pump without the water and air chamber round the
bottom of the pump barrel, the pipe B leading direct from the bottom of the
pump to a single inlét opening in the pump chamber A thus giving a free
discharge of water on to the top of the bucket or plunger 'A¹.
An air vessel B is placed over the inlet A2 and as near the pump barrel as
possible: it being made large enough to overcome the momentary pressure of air
and water, which is due to the bucket or plunger passing the inlet A³ thus
forming a cushion on the downward stroke.
The bucket or plunger having arrived at the end of its stroke the inlet from
the condenser is completely closed and the inlet from the pipe B3 open to its
full extent, so that, should there be a greater head of water in the bottom of
the pump than what is necessary the inlet A³ from the condenser being lower
than the inlet A2 from the pipe B3 the bucket on its downward stroke would
force the air and water into the vessel B first and thus retard the backward flow
of air and water into the condenser E.
In both forms of my invention the division plate D is so arranged that it may
be lifted for periodical examination or for repairs.
The water chambers form grease and dirt traps.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
(1) A steam engine air pump in which neither head, foot or bucket valves
are used in the pump chamber.
(2) A steam engine air pump constructed, arranged and operating substan-
tially as described with reference to Figs. 1 and 2 of the accompanying drawings.
(3) A steam engine air pump constructed, arranged and operating substan-
tially as described with reference to Figs. 3 and 4 of the accompanying drawings.
Dated this 30th day of July 1900,
LAWRENCE HARDIE DRAKE,
For Francis Drake.