Improvements in Air Pumps and Condensers of Steam Engines and the like.
Year: 1895

page_text: Date of Application, 3rd July, 1895
Complete Specification Left, 2nd Apr., 1896-Accepted, 23rd May, 1896
PROVISIONAL SPECIFICATION.
Improvements in Air Pumps and Condensers of Steam Engines and
the like.
We, THOMAS SMITH, WILLIAM HILL SMITH, and WILLIAM EASTWOOD,
trading as Smith Bros. & Eastwood, of Soho Works, Thornton Road, Bradford,
in the County of York, Engineers and Millwrights, do hereby declare the nature
of this invention to be as follows:-
Our invention has reference to air pumps and condensers more particularly of
the horizontal type, our object being the construction of a combined condenser and
air pump which shall have a minimum of clearance or waste space at the ends of
the stroke of the bucket, and shall also be capable of use with or without a foot-
valve or valves, which foot-valves shall be subject to a much less pressure than
those in the ordinary forms of double-acting air pumps.
Our improvement consists, first, of a harrel with slots or other suitable form of
opening in or near the middle of its length. These holes open into a chamber
formed round the barrel, and the only means of communication between the
condenser proper and the air pump is through this chamber, at or near the bottom,
which may or may not be provided with foot-valves. If foot-valves are used, the
air pump will be effective through the full length of the stroke of the bucket in
each direction. When the chamber is used without foot-valves the air pump will
be effective for only half the stroke in each direction. At each end of the barrel
are placed delivery valves opening outwards into waste water chambers, whence
the water is conducted in the usual manner. Or, the barrel may be provided with
delivery valves at one end only, and, by the addition of foot-valves to the chamber,
be used as a single-acting air pump.
Our invention also relates to a novel arrangement of delivery valves to be used
in combination with the improved air pump and condenser described above, or
with the ordinary forms of double-acting air pumps. The arrangement consists in
placing the delivery valves in a case or cases which by being twisted partially
round throws the valves out of action, and at the same time by a suitable conduit
in the case or cases connects the air pump barrel with the condensing chamber
direct as well as through the foot-valves, thus making that side of the bucket on
which the case has been turned partially round of non-effect. Or, instead of the
valves being placed in a case as described, we may obtain the same result by
altering the position of the delivery valves, or detaching the valves from their
seats, and employing suitable means to change the communication between the air
pump barrel and condenser, or between the air pump and waste water pipes at will.
The advantage of using this arrangement of delivery valves is, that a condenser
may be made which can be readily altered from full capacity to one half or one
quarter in the case of our improved air pump and condenser, or to one half if
applied to air pumps of ordinary construction, and so be suitable for extreme
variations of load on the engine, or engines.
Further, our invention relates to a method of fixing the foot-valves, so that by
a lever outside the condenser, or other suitable means, they can be readily thrown
out of action.
Dated this Second day of July 1805
THOS. SMITH.
W. HILL SMITH.
W. EASTWOOD.

page_text: DI MOTIVATION.
Improvements in Air Pumps and Condensers of Steam Engines and
the like.
We, THOMAS SMITH, WILLIAM HILL SMITH, and WILLIAM EASTWOOD
trading as Smith Bros. and Eastwood of Soho Works, Thornton Road, Bradford,
in the County of York, Engineers and Millwrights, 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 :-
Our invention has reference to air pumps and condensers more particularly of
the horizontal type, our object being the construction of a combined condenser and
air
pump, which shall have a minimum of clearance or waste space at the ends of
the stroke of the bucket, and shall also be capable of use with or without a foot-
valve or valves, which foot-valves shall be subject to a much less pressure than
those in the ordinary forms of double-acting air pumps.
Our improvements consist first of a barrel with slots or other suitable form of
opening in or near the middle of its length. These holes open into a chamber
formed round the barrel and the only means of communication between the
condenser proper and the air pump is through this chamber, at or near the
bottom, which may or may not be provided with foot-valves.
If foot-valves are
used, the air-pump will be effective through the full length of the stroke of the
bucket in each direction. When the chamber is used without foot-valves the air
pump will be effective for only half the stroke in each direction. At each end
of the barrel are placed delivery valves opening outwards into waste water
chambers, whence the water is conducted in the usual manner. Or, the barrel may
be provided with delivery valves at one end only, and, by the addition of foot-
valves to the chamber be used as a single-acting air pump.
Our invention also relates to a novel arrangement of delivery valves to be used
in combination with the improved air pump and condenser described above, or
with the ordinary forms of double-acting air pumps. The arrangement consists
in placing the delivery valves in a case or cases, which, by being twisted partially
round throws the valves out of action; and at the same time by a suitable
conduit in the case or cases, connects the air pump barrel with the condensing
chamber direct as well as through the foot-valves, thus making that side of the
bucket on which the case has been turned partially round of non-effect. Or,
instead of the valves being placed in a case as described we may obtain the same
result by altering the position of the delivery valves, or detaching the valves from
their seats, and employing suitable means to change the communication between
the air pump barrel and condenser, or between the air pump and waste water pipes
at will. The advantage of using this arrangement of delivery valves is that a
condenser may be made which can be readily altered from full capacity to one
half or one quarter in the case of our improved air pump and condenser, or to
one half if applied to air pumps of ordinary construction and so be suitable for
extreme variations of load in the engine or engines.
Further, our invention relates to a method of fixing the foot-valves, so that
by a lever outside the condenser or other suitable means, they can be readily
thrown out of action.
The accompanying drawings Figs. 1 to 19 shew in detail how we attain our
object the same letters referring to corresponding parts in all the drawings. A is
the exhaust steam pipe at entrance to condenser, B the air pump barrel, C the
condenser case, D the delivery valves for condensed steam, water, and air, E the
bed frame, the foot-valve at iulet to air pump barrel, G the guards to hold
valves in places, H a chamber through which alone connection between condenser

page_text: proper C and barrel B can be made, I the inlet for injection water, K the waste
water conduit, L the lids, M a wedge piece to secure foot-valve, N the opening in
which foot-valve is placed, P the bucket formed like a piston without valves,
R the bucket rod, S the stuffing box, T the openings for admission to the barrel,
V the valve box for delivery valves with outlet to waste water conduit K and
W the waste water pipe.
Referring to Figs. 1 and 2 the action of the air pump without foot-valves F is as
follows:-Steam enters at A and, being met by the injection water from pipe I, is
condensed and falls to the bottom of the condenser case C. The bucket P has a
reciprocating motion inside the barrel B from end to end, and approaches the
valves D as nearly as may be desired, usually within three-eighths of an inch to
three-quarters of an inch. In doing so the contents of the barrel are expelled
through the valves D into the chamber V whence they flow through the conduit K
to the waste pipe W, considering for the moment one side of the bucket only. On
the return stroke of the bucket, the delivery valves close, and as there is then no
opening into the barrel between the bucket on that side and the valves D, a
vacuum is created into which, when the bucket passes the openings T in the
barrel B, vapour, water and air rush from the annular chamber H, impelled by
the greater pressure in the condenser, whereby the pressures in the barrel and
condenser become equalised. The flow of vapour, water and air into the barrel B
continues to the end of the stroke. On the return stroke, still considering the
same side of the bucket, the pressures remain equal by the return of part of the
vapour to the condenser until the bucket passes the openings T when the remaining
contents, that is, half the capacity of the barrel, are compressed and expelled
through the valves D. In order to ensure an adequate quantity of water in the
barrel, the openings T are so placed that twice the maximum quantity required to
be discharged per stroke may be collected in the bottom of barrel. The same
action takes place on the other side of the bucket, the contents of half the barrel
being expelled through the valves, not shewn, at the opposite end of barrel.
If the chamber H is provided with foot-valves as at F, the action is the same as
described above, with this exception, that no portion of the vapour water and air
which has passed the foot-valves can return to the condensing chamber when the
return stroke takes place, by reason of the foot-valves closing immediately the
bucket P reverses, the entire contents of the barrel being thus expelled through
the delivery valves at each stroke; in other words the addition of foot-valves has
the effect of doubling the capacity of the air pump. It is also evident, firstly,
that the maximum pressure on the foot-valve is attained when the bucket has made
half the return stroke, secondly, that this pressure will be much less than if the
valve remained subject to pressure to the end of the stroke and consequently,
thirdly, that the pressure will never equal, and will generally be less than, one
half that necessary to expel the contents of the barrel through the delivery valves
against the resistance of atmospheric pressure.
Figures 3 to 17 shew details and alternative arrangements.
Fig. 3 is an end view of the valve box V shewing the delivery valves D.
Figs. 4, 5 and 54 are views of the wedge piece M.
Fig. 6 is a plan of the seat of foot-valve F.
Fig. 8 is an elevation of an alternative arrangement of condensing chamber C
foot-valve and chamber H. The barrel, delivery valves, bucket, etc. would
otherwise be as shewn in Figs. 1 and 2.
Fig. 7 is a plan of Fig. 8.
Figs. 9 and 10 are elevations of another alternative arrangement of condensing
chamber and foot-valve wedge piece.
Figs. 11 and 114 are views of the wedge piece M referred to in Fig. 8 of suitable
form for these alternative arrangements of condensing chamber.
Figs. 12 and 13 and Figs. 14 and 15 shew more completely other alternative
arrangements of the condenser.
Figs. 16 and 17 shew an alternative arrangement of the condenser made

page_text: single-acting, effective for half the length of the stroke without foot-valve and for
the full length with foot-valve.
At
Figs. 18 and 19 shew the condenser and air pump with arrangement of delivery
valves capable of being thrown out of action by being twisted partially round,
Fig. 18 being plan with the casing of one delivery valve shewn in section, and
Fig. 19 a sectional elevation through line a-b. V is the valve chamber with two
means of communication from the barrel namely by opening X to the waste
water conduit K, or by the opening Y to the condensing chamber C. The valve
casing Z which carries with it the delivery valve D may be twisted round in the
chamber V and either of these passages X or Y be opened or closed at will.
the right hand side of the figure the valve casing is shewn with the valve in
position to discharge from the barrel B through the passage X to the waste water
pipe W. On the left hand side the valve casing Z is shewn twisted partly round
throwing the valve D out of action by closing the passage X as shewn. At the
same time communication is opened up between the barrel B and the condensing
chamber C through the passage Y in the valve chamber (shewn by dotted lines)
and the corresponding opening in the valve casing.
If the condenser is provided with foot-valves and both delivery valves are in
action, the air-pump is double-acting working full capacity at each stroke; if only
one delivery valve is in action the air pump will be single-acting with half the full
capacity. If the foot-valves are taken out the efficiency of the air pump will be
reduced to one half the full capacity if both delivery valves are in action, and to
one quarter the full capacity if only one delivery valve is in action, that is it will
be double-acting in the former case and single-acting in the latter.
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 :-
:-
Firstly. In air pumps and condensers of steam engines the combination therewith
of an annular chamber H surrounding the air pump barrel B such said barrel
being provided with admission openings T situated about midway of the said
barrel substantially as shewn and described in the drawings.
Secondly. In air pumps and condensers of steam engines the combination there-
with of an annular chamber H surrounding the air pump barrel B, such said
barrel being provided with admission openings T situated about midway of the
said barrel which latter is also provided with foot-valves substantially as shewn
and described in the drawings.
Thirdly. In air pumps and condensers of steam engines the use therein of
delivery valves capable of being twisted partially around in a casing for throwing
the valves out of action in manner described and shewn in Figs. 18 and 19.
Dated this 1st day of April 1896.
TASKER & CROSSLEY,
Patent Agents, Halifax,
Agents for Applicants.