Improvements in Steam Vacuum Pumps or Pulsometers.
Year: 1892

page_text: Date of Application, 20th Aug., 1892
Complete Specification Left, 19th May, 1893-Accepted, 1st July, 1893
PROVISIONAL SPECIFICATION.
Improvements in Steam Vacuum Pumps or Pulsometers.
I, FRIEDRICH QUENSTEDT, of Cössebaude Dresden in the Kingdom of Saxony,
Engineer, do hereby declare the nature of this invention to be as follows:-
:-
This invention relates to vacuum pumps of the pulsometer kind and the object
of the invention is to provide a remedy for the irregularity of action of this class
of pump.
In the two chamber steam vacuum pumps or so-called pulsometers the
suction and delivery periods do not end at the proper time more especially with
a great height of suction and delivery when there is too large an expenditure
of steam, a comparatively small useful effect and an increased irregularity of
working.
The pump consists of a pump casing in the upper part or cover of which is
fitted a cylindrical slide. To the lower part of the pump casing is fixed the
casing for the suction and delivery valves. At the upper part of the
pump casing, formed with an enlargement, there is suspended a chamber or
hollow vessel forming between it and the pump casing a concentric passage
narrowing upwards and connecting the pump casing with the slide chest. The
suspended hollow vessel is formed at top with a flexible membrane to which the
slide rod is attached, this latter also serving to supply steam to the interior of
the hollow vessel which takes place through a small orifice in the upper part of the
slide rod, this orifice being opened and closed by means of an elastic disc, as the
slide rod moves away from or towards the top cap of the slide chest. The water
of condensation collecting in the hollow vessel is automatically expelled through a
tube connection and past a valve. Water may be injected into the pump casing
through a tube in communication with the pressure or delivery pipe.
To set the pump to work, the pump casing is charged with water and the slide is
set so as to slightly open the steam inlet which is in communication past a stop
valve with a steam generator. This position of the slide corresponds to the middle
or equilibrium position of the flexible membrane of the hollow vessel so that by the
pressure of the entering steam upon the membrane the slide connected therewith
may be fully opened. The pressure period of the pump now commences the water
being expelled from the pump casing by steam pressure and steam of like pressure
admitted through slide rod into the hollow vessel. Upon the steam and water in the
pump casing descending down as low as the upper edge of the passage leading to
the delivery pipe the equilibrium between the steam and water columns is destroyed
and diminution in the steam pressure at once takes place.
The result of the
diminution of pressure in the casing is that there is a corresponding excess of
presure in the hollow vessel so that the membrane of the same together with the
slide rises and cuts off the supply of steam to the pump casing and hollow vessel.
At this moment the automatic injection of water under pressure into the pump
casing takes place occasioning the further condensation or diminution of pressure
therein and thus the opening of the slide in this period of condensation cannot take
place. Upon the completion of the vacuum period the pump casing again becomes
charged with water where the pressure may rise to that of the atmosphere and
upwards by means of the jet supply, but previous to the jet action the hollow
vessel serves by its pulsation to open the steam slide, then, as soon as the water
drawn into the pump casing by suction reaches and surrounds on all sides the
hollow vessel the steain in this condenses, diminishing the pressure, it may be to a
vacuum, so that with slight excess pressure in the pump casing the membrane of
the hollow vessel will sink down and open the steam slide to supply steam for
another pressure period.

page_text: An equally precise action of the steam slide may be obtained if instead of
supplying steam to the hollow vessel in the manner described this is charged with
the steam or vapour of a liquid of a low boiling temperature, such as alcohol, ether,
etcetera, and hermetically closed.
Dated this 20th day of August 1892
CAPITAINE & VON HERTLING,
89, Chancery Lane, London, W.C., Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Steam Vacuum Pumps or Pulsometers.
1, FRIEDRICH QUENSTEDT of Serkowitz (formerly of Cossebaude) near
Dresden in the German Empire, 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 :—
The two chamber steam vacuum pumps or so-called pulsometers present the
disadvantage that the slide valve does not reverse or act for the cut off or
admission of steam with certainty, or at the proper time when the chambers
operate irregularly or so that their suction and pressure periods do not terminate
at the proper time. This latter evil takes place notably with great depth of
suction and great height of delivery, the result being an excessive expenditure of
steam, diminished useful effect and increased uncertainty of working.
The object of this invention is the suppression of the disadvantage referred to.
In the drawing Fig. 1 is a sectional elevation of one form of the apparatus.
a is the large chamber to the top of which is bolted a steam head and to the
lower part of the same a valve casing of a single acting pump. In the enlarged
head of the large chamber a there is freely suspended a vessel b, which is the
small chamber or reversing chamber, so that a concentric passage narrowing
upwards is formed between the two chambers, by which passage communication is
established between the large chamber a and steam head of the apparatus. The
small chamber is a closed one made airtight by rivetting soldering or brazing
and approximately of a semispherical form the upper side forming a membrane c
to which is connected a hollow slide valve rod à serving both for placing the
membrane in connection with a cylindrical steam slide e and for a steam passage
for the small chamber b. At each end the slide rod is carried in a step or bearing
and its travel is limited by collars m, m¹. It is closed at the top end.
The admission of steam to the small chamber b takes place from small inlet f
located just above collar m of the slide rod, passing out of the slide rod underneath
the membrane by orifice o the water of condensation falling to orifice o'. In the
uppermost position of the slide rod corresponding to the cut off of steam by slide e
and to the suction period of the apparatus the collar m of the slide rod bears
against the bottom surface of the upper screw cap of the apparatus thereby
shutting off by means of an intermediate elastic disc or washer the orifice f and
consequently the steam in the small chamber from communication with the large
chamber a.
The size of the steam inlet is precisely proportioned for each apparatus or its
area is adjustable by means of a conical or cock plug fitted in the closed end of the
slide rod.
In the working of the apparatus the water of condensation is automatically
removed from the small chamber past valve 9 and a pipe therefrom, and the
necessary injection or condensing water is delivered into the apparatus from
pipe h.
The working of the apparatus is as follows:-Chamber a is charged with water
and steam slide e slightly opened a position corresponding to the middle or
equilibrium position of the membrane c, then upon steam being supplied from a

page_text: When
generator past valve its pressure and action on membrane c will set slide e wide
open. At this moment the pressure period commences, the water in a being driven
out by the steam pressure, steam of like pressure entering small chamber b.
the steam and water in a reaches the edge of the passage leading to the delivery
pipe or the so-called line of condensation x, equilibrium between steam and water
columns is disturbed and a diminution of the steam pressure at once takes place.
This diminution of steam pressure in the large chamber a brings about a corre-
sponding excess of steam pressure in the smaller chamber 6 so that the membrane
of the same with the steam slide e rises and shuts off the entrance of steam to a
and b. This occurs in consequence of the comparatively large surface of the
membrane in the presence of only a small difference of pressure in the two
chambers, and further, as at this moment the con:lensation or diminution of the
steam pressure in the large chamber a continues by reason of the automatic
injection of water under pressure, and as the steam slide cannot descend or open
in this period of condensation, the injection water has only to condense the steam
enclosed in the large chamber down to a pressure sufficiently low for the height
of suction because, as distinguished from pulsometers of ordinary construction, fresh
steam cannot enter, thereby effecting a saving of steam and injection water. With
the termination of the vacuum period, the apparatus again fills with water and the
pressure in the large chamber may rise to, and above that of the atmosphere by
reason of the entrance of injection water but previous to the entrance of the latter the
small chamber effects the reversal or opening of the slide e, then so soon as the
small chamber is encompassed on all sides by the water drawn in by suction,
the steam in the same condenses causing a diminution of pressure which may reach
nearly to a vacuum so that with a small excess of pressure in the large chamber
the membrane c sinks down and opens steam slide e to admit steam for commencing
a fresh pressure period. Here also the small chamber accelerates the reversal of
the steam slide.and thereby reduces the quantity of injection water required. This
slide reversing or pulsating chamber is constructed of a thin good conducting material
of low specific temperature, copper for instance.
With the described apparatus the precision of travel of the slide valve may be
further increased in a way that may be of great advantage in the case of great
heights of delivery. It is to be observed that the steam slide e which in the middle
or equilibrium position of the membrane c is only slightly open or adjusted to a
certain area of aperture will in the pressure period of the apparatus return to this
position from the lowest position which it attains upon the entrance of generator
steam, so soon as the small chamber by the admission of steam thereto through
orifice is subject to the same pressure as the large chamber. Hence it results that,
with a corresponding adjustment of the steam orifice f, the steam slide e towards the
end of the pressure period in which the water in the delivery pipe has attained
a high velocity, returns to its normal or commencing position thereby diminishing
the supply of steam so that the expansion of the steam in conjunction with the active
force of the water column has for effect a saving of steam and notably also that of a
quiet closure of the pressure valve at the conclusion of the pressure period.
The automatic discharge of the water of condensation from the small chamber b
past valve
which is located on the bed plate outside the pump or lower down near
the lower end of the suction pipe of the same and in communication with the small
chamber by a pipe leading from the bottom thereof to underneath the valve, takes
place in the manner that water or steam can only pass the valve when it is of
sufficient pressure to lift this latter. In order that condensation water only
may automatically pass out of the small chamber the load on valve g must corre-
spond or be in equilibrium with the highest pressure present in the small chamber
plus a water column about half the height of the connecting pipe. When the
water of condensation rises in the connecting pipe, this equilibrium is disturbed at
the highest steam pressure in the small chamber, that is to say, the valve g is opened
allowing the water of condensation in the connecting pipe to pass it. This action
is repeated with each pulsation of the apparatus so soon as the steam in the small

page_text: chamber has attained its highest pressure in the pressure period, that is, the same
pressure as that present in the large chamber and which in the pressure period of
the apparatus corresponds to the counter pressure of the water column to be raised
in the delivery pipe. From this moment the passage of steam to the large chamber
diminishes in consequence of the membrane e taking the position of equilibrium but
the pressure with a suitable adjustment of slide valve e remains constant and the
velocity of the column of water in the delivery pipe only slackens before the end
of the pressure period.
The counter pressure of the column of water in the delivery pipe therefore gives
the measure for the weighting of valve g or to avoid the necessity of varying the
load on the valve according to the varying heights of delivery the water of
condensation may be led from above the valve g by a pipe into the delivery pipe
so that the pressure at the time being of the water column shall load the valve
direct, thereby always forcing the condensation water of the small chamber out of
the connecting pipe into the delivery pipe at least up to the height of the line
of condensation. It is to observed that the momentarily higher steam pressure
required at the beginning of the pressure period for opening the delivery valve of
the pump cannot extend through orifice to the small chamber and therefore has
no influence as regards the load on valve g. For the economical use of the injection
water pipe is provided with a delivery mouth the area of which may be regulated
by means of a conical valve adjustable from the outside of the apparatus as shewn,
thus allowing a variable quantity of water to be supplied from the delivery pipe
under the same pressure.
A similarly precise slide valve travel for the apparatus may be obtained by
charging the small (pulsating) chamber with the vapour of a liquid of low
boiling point such as alcohol, ether, etcetera (instead of with steam) and then
hermetically closing it. The object is to communicate to such vapour enclosed
in the small chamber a pressure from the heat of the steam of the apparatus in the
pressure period, that until the end of this period is always less than the pressure of
the water steam within the apparatus. To attain this object it is necessary to charge
chamber b specially for each height of delivery. This is accomplished by vaporising
the liquid, ether for example, contained in chamber 6 by heating this in an oil bath
of the same temperature as the steam which is required for the water columu.
small lead pipe, later easily closed, connects the chamber with the valve g which is
loaded to correspond with the pressure desired in the chamber. Upon heating the
chamber in the oil bath the atmospheric air is first driven out of the same then the
excess ether vapours discharged so that only the superheated ether vapours
the pressure of which corresponds to the load on the said valve, remain behind and
are hermetically enclosed therein.
A
This previously prepared slide actuating chamber being placed in the apparatus
the heat of the water steam will in the pressure period of the apparatus raise the
pressure of the enclosed ether vapours so that they in the same way as before
described act to shut, by excess pressure, the slide e after completion of the pressure
period and to open the same by minor-pressure (want of pressure) brought about
by the cooling action of the water drawn into the apparatus by suction.
Figs. 2, 3, 4, shew other forms of slide valve' apparatus for steam vacuum
pumps, b being the actuating chamber and the small orifice by which it is charged
with steam, c a working piston the flat head of which forms a valve e equivalent
to a slide valve and by which upon the upward travel of the piston c steam is shut
off from access to the pump chamber a and at the same time also to the chamber b
through orifice f. g is the valve for the automatic discharge of the water of
condensation from chamber b. It is loaded by the water column, and as a check
valve of this water column, is intercalated in the pipe leading from the bottom of
chamber b down to below the condensation line of the pump, thence upwards to
the delivery pipe.
Fig. 2 is a sectional view of a single acting pump which may also serve for a
sectional side elevation of the pair of pumps shewn in Fig. 3,

page_text: By the substitution of an organ, working piston like, for the flexible membrane
of Fig. 1 the method of working is not sensibly altered. The modification has for
object to facilitate the execution of the steam valve mechanism.
For the purpose of obtaining a constant delivery two pumps of the kind shewn
in Fig. 2 are connected together or formed in a pair (Fig. 3) with one steam, one
suction and one delivery pipe common to both, and the valve actuating chambers b
of the same are in communication with each other by a passage o closeable by a
cock k. As each pump has a separate steam valve apparatus they may when cock &
is shut be worked independently or separately.
This apparatus works as follows:-Supposing the two pump chambers a to be
respectively in the pressure and suction period steam will pass by open valve e into
chainber a and also through orifice into the corresponding valve actuating
chamber of the one pump which is under steam pressure, then also steam will
pass through passage o into the chamber b of the other pump which is under suction
the steam valve e of which remains closed in this period.
As soon as a lessening of pressure takes place at the line of condensation the
valve e in consequence of the excess pressure in the actuating chamber 6 closes
to shut off steam both from chamber a under pressure and from its slide actuating
chamber.
At this moment when both steam valves of the apparatus are closed and
the steam shut off from actuating chambers both pump chambers act by the
cooling or condensation of the steam in the actuating chambers, whilst the steam
in the space above the valves e increases in pressure or attains boiler pressure.
An excess of pressure is consequently produced in the pump chamber already taking
pressure from the entering water by which the steam valve e of the same is opened
and steam for the pressure period admitted into this chamber. The same action
is repeated, as with the opening of one steam valve e steam passes into both of
the actuating chambers which are united by passage o consequently keeping the
steam valve, of the pump under suction, closed until the completion of the pressure
period in the other pump.
This alternating action of the steam valves e also takes place when in stang
the pumps both chambers are filled with water and simultaneously receive steam
as in consequence of the unequal resistance of the delivery valves the action of one
pump chamber will get ahead of the other. The action of the pumps may be
more quickly regulated by setting them to work one after the other by means of
special stop valves which may also serve for the separate driving of each pump.
Similarly two single acting pumps at a distance from one another may be worked
in the same alternating manner when in connection with one and the same steam
supply pipe and when the valve actuating chambers are in communication with
each other by a pipe.
The construction shewn in sectional elevation in Fig. 4 has likewise for object
a constant or steady delivery. It also consists in placing a pair of pumps of the
kind shewn in Fig. 2 in connection with a common suction and delivery pipe but
as distinguished from the arrangement of Fig. 3 the connection of the two actuating
chambers b is established by means of an oscillating double lever p in such a way
that these steam valves must operate in a determined way and in a contrary direction
to each other, each reversing at the same time. Generally this method of con-
necting the actuating chambers gives a favourable-result that is without particular
loss of useful effect of the pumps only when they are both previously unloaded or
under the same pressure as the pump chambers as in the time steam is passing
during the pressure period to one of the actuating chambers, the piston or sliding
organ of this chamber, by reason of the excess pressure in the pump chamber acts
in a direction contrary to that of the valve travel until the steam charge of the
actuating chamber is completed and freedom of movement for the piston like
organ c of the same thereby obtained. The same obtains in the pump chamber
under suction until the pressure in this corresponds to that of the actuating
chamber.

page_text: A favourable operation of the steam valves takes place with a simultaneous
ending of the suction and pressure period as both actuating chambers are then
unloaded and support each other in their valve motion.
The means by which it is here endeavoured to bring about the simultaneous
completion of the periods in two chamber steam vacuum pumps comprises the
regulation of the steam distribution to the actuating chambers by means of cock f¹
(Fig. 4) arranged in the passage f. Seeing as already mentioned, that the actuating
chamber until it has received its charge of steam acts inversely to the motion of
the steam valve, by lengthening as is hereby done the time during which the
actuating chamber remains charged, the reversal of the steam valve of the same
may be delayed, on the suction side of the pump without thereby affecting the
velocity of the pump stroke.
A further favourable result of the same steam distributing apparatus arises from
the circumstance that with a complete steam charge of the actuating chamber on
the pressure side of the pump by which its piston c is unloaded or in equilibrium,
therefore free to move in the steam space, the actuating chamber on the suction
side of the pump upon earlier completion of the suction period, can automatically
reverse the steam valve before the steam in the pressure chamber a has reached
the line of condensation. The steam is thereby suddenly enclosed in this chamber
and operates, at first by expansion, on the moving water column. Its further
lowering of pressure then takes place by reason of the admission of injection water
from the adjoining chamber, as this latter at the moment of the steam valve
reversal is placed under greater pressure than corresponds to the water column,
or than the pressure of the enclosed steam, owing to the increasing pressure taking
place before the opening of the delivery valve, so that the commencement of the
suction-period within the pump chamber is thereby brought about and may continue
its course with the aid of injection water in the ordinary way.
This course upon corresponding adjustment of the pump stroke, especially by
regulating the steam admission to the actuating chamber, will be repeated in the
pressure (pump) chamber.
Accordingly with this steam valve motion the evacuation or lowering of the
pressure of the working steam down to the line of condensation for the purpose of
the reversal of the pump stroke is rendered unnecessary, thus rendering the valve
motion suitable for pumps delivering at great heights.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. A steam admission or slide valve apparatus for steam vacuum pumps con-
sisting of a slide actuating chamber b which provided with a small orifice fis
through this charged during the pressure period of the pump with steam up to a
pressure as high as that in the pump chamber a, so that it, acted upon by the
pressure within it, closes through a membrane c a steam admission or slide valve e,
80 soon as upon completion of the pressure period a minor pressure is produced in
the pump chamber, on the other hand upon completion of the suction period opening
again said steam admission or slide valve so soon as the steam in the actuating
chamber bis condensed by the suction water encompassing said chamber down to
atmospheric pressure whereupon the water of condensation within the actuating
chamber is in the pressure period of the pump automatically discharged past a
valve g, substantially as described and shewn.
2. A modified construction of the apparatus referred to in which the actuating
chamber charged with a small quantity of a liquid of low boiling temperature
and hermetically closed has evolved within it during the pressure period vapour of
a certain pressure by the steam heat of the pump chamber so that by means of
such pressure the actuating chamber upon the completion of the pressure period
closes a steam admission valve e and upon the completion of the suction period

page_text: opens said valve e through membrane c in consequence of the condensation of the
vapour therein by the suction water, substantially as described and shewn.
3. A modified construction of the apparatus referred to in Claim 1 in which
instead of the flexible membrane c a moving piston like organ c is employed,
substantially as described with reference to Figs. 2, 3 and 4 of the drawings.
4. A modified construction of the apparatus referred to in Claim 1 in which for
the purpose of obtaining a steady delivery the actuating chambers of two pumps
delivering into one pipe are in communication with each other by a pipe or passage o,
substantially as described with reference to Fig. 3 of the drawings.
5. A modified construction of the apparatus referred to in Claim 1 in which for
the purpose of obtaining a steady delivery the piston like organs c of the actuating
chambers of two pumps delivering into one pipe are in connection with each other
through a double lever in such a way that they act in conjunction with each
other but in opposite directions, substantially as described with reference to Fig. 4
of the drawings.
Dated this 19th day of May 1893.
CAPITAINE & VON HERTLING,
89, Chancery Lane, London, W.C., Agents for the Applicant.