Improvements in Turbines Driven by Steam or Gas.
Year: 1896

page_text: Date of Application, 3rd Ja 1., 1890
Complete Specification Left. 2nd Oct. 1896-Accepted 2nd Jan. 1897
Complete Specification Left. 2nd Oct. 1896-Accented 2nd Jan. 1897
PROVISIONAL SPECIFICATION.
Improvements in Turbines Driven by Steam or Gas.
We, LOUIS BOLLMANN, an Engineer, II. Obere Donaustrasse 93 in Vienna,
Austria, and SALOMON KOHNBERGER, a Manufacturer, IX. Lichtenstein-
strasse 14, Vienna, Austria do hereby declare the nature of this invention to be
as follows:-
The herein described improvements relate chiefly to such turbines driven by
steam or gas, for which a British Patent No. 6822 A.D. 1894 has been granted to
Louis Bollmann, one of the joint applicauts of the present specification, to which
patent we herewith refer. The letters of reference in the drawings of the said
patent, denote the same or similar parts in the present specification.
Fig. 1 is a longitudinal central section, and Fig. 2 a front view, partly in cross
section, of a turbine driven by a mixture of steam of a high pressure and atmospheric
air (or its equivalent) as described in said patent.
The form of the guides and of the buckets of the single wheel L and T, are
shown in Fig. 3 in section through the line (Fig. 1).
The channels of the wheel T are made conical, each representing a conical
diverging tube, Fig. 4, in which a current in the direction of the arrows 1-2
produces a sucking action at the wider end p.
The atmospheric pressure acts on both ends of the tube, driving the current on at
the narrower end o, and retarding it at the wider one p. But as the area is larger
at p, the retardation is greater, than the acceleration at o, and consequently the
velocity of escape is reduced.
If the proportion of the weight of steam and air is 1 to 40, as stated in said
patent, the channels of the wheel T should be 3 times as wide at the discharging
side, than at the entrance, in order to produce the same effect of reducing the
velocity of escape of the mixture, and of the rotations of the wheel, as with a
serial turbine; the driving force is thereby increased by the reacting pressure
of the outside air, acting on both sides of the channels in the direction of
rotation.
Experiments have shown, that for large motors a longer distance is required
for perfectly mixing a sufficient quantity of air with the steam, than can be obtained
between the plates K K₁, without increasing their diameter to an impracticable
extent.
The air is at first forced along by the flat steam current, with accelerating
velocity, and it requires a certain time and length of way, until steam and air have
acquired the same speed.
The Figs. 5 and 6 show an arrangement for increasing the distance for mixing,
and for furthering the diffusion of the steam and air. Fig. 7 is a diagram, showing
the circumference of the turbine in section through the line (Fig. 6) in flat
extended condition, being size of Figs. 5 and 6.
The mixture flowes through the guiding channels L from the space between KK,
into the circular space R in such direction, that it must rotate in the same, as is
indicated by the arrows in Fig. 7. m are partitions, placed screw like into the
space R, so as to guide every part of the current to make one revolution, before
it can enter the second guides and the buckets of the wheel T.
The guiding buckets L divide the flat current into single streams, each con-
sisting of a central part of higher velocity, surrounded by air, which has not yet
acquired the full speed. These streams are stratified side by side, while entering

page_text: the space R, producing thereby a most perfect mixing of the current, while it
makes the long way in the circle. The quantity of air admitted for one pound of
steam can he increased by this arrangement, which is economically favourable,
and allows also a reduction of the revolutions of the turbine wheel.
Form, position and proportional size of the space R, can be altered from those
shown in the drawing."
By increasing the dimensions of the space R, and the number of partitions m,
and disposing the latter accordingly, the mixture can be forced to rotate more
than once, before it enters the turbine.
The space R may be formed so, that its section Fig. 6 is like a reversed S, the
current rotating then screwlike at first from left to right, as in the figures, then
from right to left, and lastly again to the right towards the wheel.
The partitions m may be omitted, the freely rotating current finding itself the
screwlike way towards the wheel.
If the front plate K is formed as a ring, so as to be open in the middle (about
till in Fig. 6) the atmospheric pressure holds the uncovered part of the current
towards the inner plate K, giving it the appearance of a plate of glass. The
quantity of air admitted can then be regulated, by altering the distance between
plate K, and the ring plate K.
The Figs. 8 and 9, show an arrangement for reducing the enormous high
velocity, with which the steam passes according to the other figures into the space
for mixing it with the air. Fig. 8 is a cross-section througli the middle of the
space between the plates KK; Fig. 9 is a central longitudinal section.
The mixing space between the plates K K, is formed into conical spiral channels,
(Fig. 8) narrow near the centre, and wide towards the circumference; they have
suitable apertures k, to admit outside air, (which are shown in Fig. 8 only for one
of the 4 channels) and are made of such an angle to the channels, that the air must
enter nearly in the direction of the current.
The conical form of the channels, aud the slant direction of the airholes
produces a suction for drawing in the air, if the steam or the mixture flowes
with a velocity, much lower than that, produced by plates A B, in Fig. 1. For
steam of 10 atmospheres, this velocity might be about 200 meters or 675 feet
per second, which is th of that for the plates A B, as described in the said
patent.
If the areas of the channels are at N such, that the required quantity of steam
of 10 atmospheres must enter them with the above velocity, air will be drawn in
through the first airhole k₁, and when the current reaches the next following hole,
its condition is altered according to the quantity of air previously mixed with it.
By adjusting the size of each succeeding airhole along the spiral channels, to
admit at every point the required quantity of air, the current can be kept at a
relative low velocity. The steam begins at once, to impart its energy to the air
entered into the expanding channels, the inertia of which acts as a resistance
towards the small end N, and prevents the steam from acquiring a high speed,
which furthers the mixing and prevents noise and friction.
The current passes from the spirals with a rotating motion through the guides L
into the buckets T of the turbine wheel.
This arrangement can be combined with any of those, previously described in
the said patent or in this specification, and its form and construction may be
modified in many different ways. The plates K K, (Figs. 8 and 9) can be arranged
so, that they will rotate instead of the wheel 1, in which case it works as a
reaction turbine. A part of the driving force is then produced by the current
acting against the entering air, to set it in motion, which causes a reacting pressure
against the spirals.
Dated this 30th day of December 1895
LOUIS BOLLMANN.
SALOMON KOHNBERGER.

page_text: COMPLETE SPECIFICATION.
Improvements in Turbines Driven by Steam or Gas.
We LOUIS BOLLMANN, an Engineer, II. Obere Donaustrasse 93 in Vienna,
Austria and SALOMON KOHNBERGER, a Manufacturer, IX Lichtensteinstrasse 14
in Vienna, Austria 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 :-
These improvement relate chiefly to turbines driven by steam or gas of the
system, for which a British Patent No. 6822 A.D. 1894 has been granted to Louis
Bollmann, one of the joint applicants of this present specification, to which patent
we herewith refer.
The letters of reference in the drawings of the said patent denote the same or
similar parts in the present specification.
The plates III and III of the drawings are those left with the Provisional
Specification; plate I is newly added with this Complete Specification.
Figure 1 is a longitudinal central-section and Figure 2 a front view, partly in
cross-section of a turbine as described in said previous patent, driven by a mixture
of steam and air (or their equivalents), but having only a single turbine-wheel T.
The form of the buckets of T and of the immovable guides L, are shown in Fig. 3
in section through the line, in Fig. 1.
The channels of the wheel T are formed wider at the exhaust side (next to : in
Fig. 1), than next to the guides L, each representing a conical diverging tube,
Fig. 4, by which the velocity of a current, passing through it in the direction of
the arrow 1, is reduced. The object of this arrangement is, to diminish the
rotating speed of the wheel, which depends, according to the general theory of
turbines, on the velocity, with which the current passes from the turbine into the
exhaust space S (Fig. 1).
According to the theory of discharge from conical diverging tubes, is the
velocity of a current, passing through it in the direction of the arrow 1, (Fig. 4),
accelerated at o, and retarded at the wider end p.
This effect is caused by the atmosphere pressing against both ends; at o in the
direction of the current, and at p against it (arrow 2). The area being larger
at p, the current is partly pushed back into the wider space by the atmosphere,
while the vis-inertia of the same tends to continue the velocity, and thereby
produces a suction at o, which accelerates the current there.
If V, denotes the velocity of the current before entering the tube; V₁ and V11
the same at the entrance o, and at the discharge p; = , the proportion of the
V₁
11
areas at both ends, and H the height of fall, due to the changes of the velocity,
then is:

page_text: The atmospheric pressure acts on the conical channels of the turbine wheel T,
(Fig. 3) in the manner above described, retarding the discharge of the mixture
into the space S (Fig. 1), and producing a suction, which accelerates the current,
entering through the guides L. The number of revolutions per minute are thereby
reduced, but the motive power is not altered, because the atmosphere, as well as
the increase of ris-inertia on the entrance, press both against the wheelbuckets
(Fig. 3) in the direction of their rotation (arrow 4) and increase the driving force
proportionally, so that the working effect remains unaltered by this reduction of
the rotating speed.
If a circle of stationary guides (similar to those L) is placed against the exhaust
side of the wheel, (at the right hand side of Fig. 3) the current will be positively
forced to exhaust at right angle to the wheel; this will assist or increase the effect
of the described conical channels. The conical diverging shape of the channels
may be extended also to the stationary guides.
Experiments have shown, that for large motors a longer distance is required for
perfectly mixing a sufficient quantity of air with the steam, than can be obtained
by the length of the radius of the plates K K₁, without increasing the latter to an
impracticable extent. The air is driven by the flat steam-current between K Ki
with accelerating velocity, and it requires a certain time and length of way, until
steam and air acquire the same speed. There is therefore some suitable space
required, in which the mixture passing from the space between the plates, can pass
a certain distance, to produce a perfect equal speed of steam and air, before passing
through the turbine.
Figs. 5 and 6 show such an arrangement. Fig. 7 is a diagram, showing the
circumference of the turbine in section through the circular line, (Fig. 5) in flat
extended condition, being half size of Figs. 5 & 6.
The mixture passes from the space between the plates KK, through guiding
channels L into the circular space R in such tangential direction, that it must
rotate, as is indicated by the arrows in Figure 7. m are partitions, placed screw-
like into the space R, so as to guide the current, to make one revolution around
the axis, before it can enter the second guides L, and the buckets of the wheel T.
Another arrangement for the same purpose is shown in longitudinal central
section in Fig. 11, whereby the mixture is led in radial direction zigzag. M N is
the axial line of the turbine. The steam flows as a flat jet at b, from the injector,
and draws the air by suction through the large opening of the plate Kinto the
space between K K₁, from where it passes in a curve towards the axis M N, and
then between the second pair of plates, from where it may be led to the turbine,
(which is not shown in the figure) or as shown in Fig. 11, again zigzag through a
third pair of plates, and then at J, towards the turbine.
Additional steam-jets b b might be used for the second and third pair of
plates, each of which will accelerate the mixture; and there can also fresh air be
drawn in by each jet, for which suitable openings k₁₁ k are made.
The first jet acts hereby as a ventilator or blower for the next one bu;
a large quantity of air can thus be perfectly mixed with the steam, which reduces
the speed of the wheel, and increases the action of the steam.
Fig. 12 is a longitudinal section through the axial-line M N, and Fig. 13 a cross-
section of the steam-injector, forming three separate jets by bu b
The hollow parts B, B B are channeled (Fig. 13), so as to form passages for
the steam, entering through E, to the narrow circular slits, through which the flat
jets by bb escape. a is a spindle, forming three screws, each of another pitch,
which gear into the parts B, B₁ B. The screw for B₁ has the largest pitch,

page_text: and that for B, the finest. By rotating the spindle by a hand-wheel near N, the
width of the slits can be adjusted.
The plate K (Fig. 11) being formed with a large opening or ringlike, while the
other one K, is closed, causes the outside air to press the flat jet of steam against
the inner plate K₁, so that the jet appears like a plate of glass. This produces a
free admission of air and an increase of its mixture with the steam.
The Figs. 8 & 9 show an arrangement for reducing the enormous speed, with
which the steam passes into the space between the plates K K₁ of the previous
figures.
Fig. 8 is a cross-section through the middle of the space between the plates KK, ;
Fig. 9 is a longitudinal section.
The mixing space between K K₁ is formed into conical spiral channels, (Fig. 8)
narrow near the centre and wide outside; they have suitable apertures k, to admit
outside air, which are formed at an angle to the chaunels, as shown in Fig. 10, so
that the air must enter nearly in the direction of the current.
The airholes are shown in Fig. 8 only for one of the 4 channels.
The slanting direction of the airholes, and the conical diverging form of the
channels, produces a suction of air, even by a moderate flow of the steam, which
enters at N. If the dimensions of the channels and the number and size of the
airholes are properly arranged, so that at every point the required quantity of air
is admitted, the current can be kept at a relative low velocity. The steam begins
at once to impart its energy to the air, entering the expanding channels, the inertia
of which acts as a resistance towards the narrow ends at N, and prevents the steam
obtaining the high speed, with which it would pass freely into the air; this
arrangement furthers the mixing, produces a smooth action and prevents noise and
friction. It can be combined with any of those, previously described, and its form
and construction may be modified in different ways.
The plates K K, can be arranged, so that they will rotate instead of the wheel T,
in which case it works as a reaction-or scotch turbine. A part of the driving.
force is then produced by the current, acting against the entering air to set it in
motion, which causes a reacting pressure against the spiral channels.
The wheel T can then be made stationary, to act as guides on the exhausted
mixture, in the sense above explained for Fig. 3.
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:
In a turbine driven by a mixture of steam (or gas) and air, or other gaseous
substance:
1. The conical diverging channels (Figs. 1 and 3) or their equivalents, for the
purpose of diminishing the velocity of the exhausted mixture and the number of
rotations of the turbine per minute.
2. The application of a circle of stationary guides at the exhaust side of the
turbine wheel.
3. To construct one of the plates open, or in form of a ringplate (K, in
Fig. 11) while the other one is closed, in order to produce a free entrance of the
air, which presses the jet against the closed plate.
4. Leading the mixture from the space between the plates KK, through a
space R (Figs. 5, 6 and 7) or zigzag between two or more sets of plates, (Fig. 11)
in order that it must pass a longer way for mixing the air more perfectly with the
stean, before passing through the turbine.
5. The arrangements for applying more than one flat jet of steam (b, bu b
Fig. 11) to the air, to increase the energy of the turbine, and to further the perfect
mixing of the air with the steam.
6. The spiral channels (Figs. 8 and 9) for diminishing the velocity of the steam.
or gas, as herein set forth.

page_text: 7. To make the plates K K, (Figs. 8 and 9) rotating so as to act as a reaction-
wheel or as a scotch-turbine.
8. To construct the airholes of the plates K K₁ slanting (Fig. 10), so that the
air must enter nearly in the direction of the current.
Dated this 29th day of September 1896.
LOUIS BOLLMANN.
SALOMON KOHNBERGER.