Improvements in Jets for Fluid Pressure, and in Apparatus Employing Jets.
Year: 1891

page_text: Date of Application, 8th Oct., 1891
Complete Specification Left, 8th Aug., 1892-Accepted, 10th Sept., 1892
PROVISIONAL SPECIFICATION.
Improvements in Jets for Fluid Pressure, and in Apparatus
Employing Jets.
I LUDWIG ZECHMEISTER of Landwehrstrasse 54 Munich in the Empire of
Germany Mining and Factory Engineer do hereby declare the nature of this
invention to be as follows :—
This invention relates to apparatus such as steam or chimney blast, ventilating
apparatus, dust removers, air and water heaters or coolers or other apparatus in
which the desired effect is produced by the action of a jet or jets of fluid (air steam
or other gas, water, or other liquid) on another body or current of fluid set into
motion by said jet or jets so that the swift motion from the jet is transferred into a
slow motion of the fluid or matter moved or so that the caloric of the one is
transferred to the other according to the purpose of the apparatus.
The issue openings of the blast pipe are diminished to an extraordinary small
size, thus for pressure above 2 atmospheres (absolute) they are reduced to 0.5 to 1/
(0-2 to 0.8 sq. section) for very large volumes or very small pressure to 1 to 2™
(0-8 to 3-29 sq.m sectional area). Where the supply is intermittent for instance
when derived from the exhaust steam or exhaust gases from a steam or gas engine,
the jet issue opening is made twice or three times as large as above indicated. As
the working of the jets is a consequence of the contact of the currents, the cross
section of the jets is reduced, while if necessary the number of the jets is corre-
spondingly increased.
The openings of the jets are made three, four, or five cornered, semi circular oval
elliptic, ogival, star or crescent shaped, or clover key pattern in cross section or
by making the same as straight or curved slits of exceedingly small breadth so that
the vibratory currents issuing from such deformed openings, act by their nodes and
loops to increase the effect of contact in a large degree.
To render the stream from small outlet openings regular and avoid loss of
pressure and to provide for the unhindered flow of the medium acted upon it is
preferable to use conical nozzles the convergence of which is about 13°. For the
larger jets cones are also preferred. Very small jets of about 0.5 m/m diameter
should only be made conical and either round or oval
With high pressure of air or steam etc. the conical converging jets may be
provided with conical diverging additions. The enlarging of sectional area made
thereby should however be very small about twice to four times that of the
narrowest part of the passage to concentrate as much as possible the highly
compressed air or steam as it issues and direct the same forward and prevent undue
spreading to the sides.
For the convenient cleaning and changing of the separate nozzles the latter are
carefully turned and removably inserted into the aforesaid ends from behind. For
keeping the nozzles clean fine sieves may be placed in the feed pipes, or with
compressed air a washing apparatus similar in action to a washing bottle used in
the practice of chemistry is employed.
If the volume of pressure fluid is great or the sectional area of delivery large
or if a more instantaneous effect is desired, the number of nozzles is increased
and these are arranged evenly over the whole sectional area of the delivery
opening. The latter is divided into as many parts as there are nozzles and a
nozzle is arranged in the centre of each of these parts without the trunks or canals
however being divided by any walls or partitions. To increase the action of the
nozzles they may be arranged steeple fashion. Where there is but one nozzle it is
placed in the middle of the tube. Roses may be used in place of nozzles, the cover

page_text: plates of these roses being provided with openings of the aforesaid shapes or with
conical tubes having the said openings. The boring or punching of the openings
or the bending of the tubes should be so done that the issuing currents are as far as
possible parallel to each other.
The delivery pipe for large effect as for the removal of air or other gas is
made of sectional area about 10,000 to 100,000 as large as that of the nozzle
opening and not less than 8 to 16 times its diameter in length. For quicker delivery
it is made correspondingly narrower the narrowest being for steam injectors or for
bilge ejectors.
In using steam or compressed air apparatus the feed tubes are carried along the
walls of the shaft (furnace flues &c.) and arranged in spirals therein so as to be
warmed by the smoke and waste gases which increases the effect.
As steam contains an appreciable amount of latent heat by suitable raising or
lowering the quantity and pressure of the steam with the help of a small previous
warming of the air, the warming of the latter can be regulated according to desire
so that for providing an air heating system there is substantially nothing else
required than to set up such an apparatus as is here described in which the air to be
drawn along may be regulated by dampers etc., so that the quantity drawn in may be
raised or lowered. Warmed and moistened air may thus be obtained. With the
help of injectors and use of compressed air it is also possible to regulate the heat
of the incoming air by raising or lowering the air pressure and consequently the
speed with which the air passes the heating apparatus.
With apparatus working with intermittent pressure and in which back pressure
is to be avoided as far as possible the nozzles are enlarged or their number is
increased so that the amount of opening formerly employed or even a greater
amount is obtained. With steam engines with several cylinders, coupled gas
-engines or the like each exhaust must have its separate opening. The uniting of
the outlets of several exhausts should in general be altogether avoided, should this
however be desired in any case the area of section at the end of the outlet with the
above sections should not be smaller than the area of each exhaust pipe where the
latter joins the collecting pipe so that on the one hand the pressure at the outlet
should not be weakened and on the other hand there should be no back pressure on
the other exhaust pipes. Each outlet is given the full area of section of the blast
pipe feeding the same but is of the deformed shape before described. To increase
the effect especially for the blast of locomotive engines four to six blast pipes may
be arranged in a circle in the chimney. The first, third, fifth etc., being in
connection with one of the cylinders, the second, fourth sixth etc., with the other
cylinder. The auxiliary live steam blast pipe may then be small and of the afore-
said "deformed" cross section since it operates with a continuous jet. It may be
placed in the middle. As the use of the cross sections before mentioned gives a
greatly increased current effect it allows of the use of larger openings of the steam
blast with reduction of back pressure and increase of effect of the steam engine
especially of a locomotive.
With compressed air, a wind chest of suitable size may be inserted and filled
with compressed air. This chest being shut off when sufficiently charged with air
under pressure may then be used for the slow action of producing air currents for
the apparatus until the pressure is used up.
In employing this system for ventilation purposes, in the ceiling of the room to
be ventilated is placed a large pipe provided along its whole length with little
round or deformed openings or similar small nozzles so that the air rushing in mixes
with the air of the room and is warmed. A second parallel pipe with a similar
series of large round openings carries off the foul air into the open or into a flue
or chamber. The above described pressure blast apparatus may be placed in this
pipe and set in action.
The jet apparatus described is especially suitable for transferring the temperature
of a gas or of a fluid to another, thus for the cooling of air by means of water for
"the condensation of steam by water jets or conversely for the cooling of warm

page_text: streams of water by means of the air drawn in in place of step coolers the gas or
liquid material under pressure or driven by pressure being caused to act by suction
on the fluid to be drawn in.
The deformed shape of jet openings may also be used with good effect in various
jet pumps, steam injectors, jet blasts, apparatus for carrying along solid matters
such as dust removing ventilators ete. The various forms and constructions used
up till now would remain unaltered only the shape of cross section of the opening
for the passage of the driving fluid will be altered in the manner stated.
If we place in a current of air, gas, or water a pipe with its mouth lying in the
direction to which the current is flowing a vacuum is formed in front of the mouth
of the pipe which draws upon the contents of the pipe. In this case we have a
condition actually contrary to that previously described herein, the actuating
current surrounds the pipe in which a suction is to be produced and the volume of
the actuating current is greater than the derived current. This is the case with
chimney cowls and the like, of the "lobster back" pattern.
In applying my invention to this purpose, the movable bent pipe, chimney head or
cowl is made as far as possible flat in cross section, oval, or rectangular with two
long and two short sides or star shaped or otherwise with its sides of the
deformed shape as described. The circular form is only to be used with small
cross sections in which the avoiding of the formation of a dead centre need not be
attended to.
These movable pipes are provided on the side which meets the current of wind
with a divider which causes the wind to pass to each side of the pipe without
appreciable opposition and so arrive with full force near the mouth of the pipe so
that the full drawing power of the current may be operative all round the mouth'
from which the air or smoke etc. to be exhausted issues.
When large quantities of gases are to be drawn out several such flue additions
are used.
In the last case the function of the parts is changed the driving fluid is outside
including the fluid to be driven sucks it up and carries it along.
I proceed in the same way in all cases when the bulk of the driving fluids is
greater than that of the driven, amplifying as much as possible the circum-
ference of the openings by aid of the aforesaid sections and multiplication of
opening.
The advantages of the apparatus are the following.
1. Departing from very small forms their enlargement or multiplying provides a
corresponding increase in their efficiency.
2. They allow of an extraordinary extended use of the pressure fluid and a wide
spreading utilization of the latter.
3. They may be easily adapted for high or low pressure by altering the section
of outlet.
4. The apparatus is exceedingly simple and therefore cheap even the most
complete.
5. They do not wear out easily, are light to support and easily cleaned.
6. They are easily constructed in various materials and may be put together
readily.
7. They provide for the carrying out of draughtless ventilation at the smallest
cost.
Dated this 8th day of October 1891.

page_text: COMPLETE SPECIFICATION.
Improvements in Jets for Fluid Pressure, and in Apparatus
Employing Jets.
I, LUDWIG ZECHMEISTER, of Landwehrstrasse 54ª, Munich, in the Empire of
Germany, Mining and Factory 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 :-
This invention relates to apparatus such as steam or chimney blast ventilating
apparatus, dust removers, air and water heaters or coolers or other apparatus in
which the desired effect is produced by the action of a jet or jets of fluid (air, steam
or other gas, water, or other liquid) on another body or current of fluid set into
motion by said jet or jets so that the swift motion from the jet is transferred into a
slow motion of the fluid or matter moved or so that the virtual velocity and the
caloric of the one is transferred to the other according to the purpose of the
apparatus.
The essential parts of such apparatus are:
The jet itself and the suction and delivery pipes the latter forming possible
chimney cowls.
We begin with the jets.
The issue openings of the blast pipe are diminished to an extraordinary small
size, thus for pressure above 2 atmospheres (absolute) they are reduced to 0.5 to
1 (0-2 to 0-8 sq.m section), for very large volumes or very small pressure to
1 to 2 (0-8 to 3.29 sq. sectional area). Where the supply is intermittent, for
instance when derived from the exhaust steam or exhaust gases from a steam or
gas engine, the jet issue opening is made twice or three times as large as above
indicated. As the working of the jets is a consequence of the contact of the
currents, the cross section of the jets is reduced while if necessary the number of
the jets is correspondingly increased.
The openings of the jets are made three, four, or five cornered, semi-circular,
oval, ellíptic, ogival, star or crescent shaped or clover key pattern, in cross section
or by making the same as straight or curved slits cf exceedingly small breadth so
that the vibratory currents issuing from such deformed openings act by their nodes
and loops to increase the effect of contact in a large degree, Fig. 1.
To render the stream from small outlet openings regular and avoid loss of
pressure and to provide for the unhindered flow of the medium acted upon it is
preferable to use conical nozzles the convergence of which is about 13°. For the
larger jets cones are also preferred. Very small jets of about 0.5" diameter
should only be made conical and either round or oval.
With high pressure of air or steam etc., the conical converging jets may be
provided with conical diverging additions as shown in Fig. 2. The enlarging of
sectional area made thereby should however be very small, about twice to four
times that of the narrowest part of the passage, to concentrate as much as possible
the highly compressed air or steam as it issues and direct the same forward and
prevent undue spreading to the sides.
For the convenient cleaning and changing of the separate nozzles the latter are
carefully turned and removably inserted into the aforesaid ends from behind. For
keeping the nozzles clean fine sieves may be placed in the feed pipes, or with
compressed air a washing apparatus similar in action to a washing bottle used in
the practice of chemistry is employed.
If the volume of pressure fluid is great or the sectional area of delivery large or
if a more instantaneous effect is desired, the number of nozzles is increased and
these are arranged evenly over the whole sectional area of the delivery opening.
The latter is divided into as many parts as there are nozzles and a nozzle is
arranged in the centre of each of these parts without the trunks or canals however

page_text: being divided by any walls or partitions (Fig. 3 shows an example). To increase
the action of the nozzles they may be arranged steeple-fashion Fig. 4. Where
there is but one nozzle it is placed in the middle of the tube. Roses may be used
in place of nozzles the cover plates of these roses being provided with openings of
the aforesaid shapes or combined conical tubes having the said openings. The
boring or punching of the openings or the bending of the tubes should be so done
that the issuing currents are as far as possible parallel to each other.
The delivery pipe for large effect as for the removal of air or other gas is made
of sectional area about 10,000 to 100,000 as large as that of the nozzle opening,
and not less than 8 to 16 times its diameter in length. For quicker delivery it is
made correspondingly narrower, the narrowest being for steam injectors or for
bilge ejectors.
In using steam or compressed air apparatus the feed tubes are carried along the
walls of the shaft (furnace flues etc.,) and arranged in spirals therein so as to be
warmed by the smoke and waste gases which increases the effect.
As steam contains an appreciable amount of latent heat, by suitably raising or
lowering the quantity and pressure of the steam with the help of a small previous
warming of the air, the warming of the latter can be regulated according to desire
so that for providing an air heating system there is substantially nothing else
required than to set up such an apparatus as is here described in which the air to
be drawn along may be regulated by dampers etc., so that the quantity drawn in
may be raised or lowered. Warmed and moistened air may thus be obtained.
With the help of injectors and use of compressed air it is also possible to regulate
the heat of the incoming air by raising or lowering the air pressure and conse-
quently the speed with which the air passes the heating apparatus.
With apparatus working with intermittent pressure and in which back pressure
is to be avoided as far as possible, the nozzles are enlarged or their number is
increased so that the amount of opening formerly employed or even a greater
amount is obtained. With steam engines with several cylinders, coupled gas
engines or the like each exhaust must have its separate opening.
Fig. 5 shows different arrangements with the above given sections two mouths
connected together and separated by a partition.
The uniting of the outlets of several exhausts should in general be altogether
avoided, should this however be desired in any case, the area of section at the end
of the outlet with the above sections should not be smaller than the area of each
exhaust pipe where the latter joins the collecting pipe so that on the one hand the
pressure at the outlet should not be weakened and on the other hand there should
be no back pressure on the other exhaust pipes. Each outlet is given the full area of
section of the blast pipe feeding the same but is of the deformed shape before
described. To increase the effect, especially for the blast of locomotive engines,
four to six blast pipes may be arranged in a circle in the chimney, the first, third,
fifth etc., being in connection with one of the cylinders, the second, fourth, sixth, etc.,
with the other cylinder (Fig. 6). The auxiliary live steam blast pipe may then be
small and of the aforesaid "deformed
cross section, since it operates with a
continuous jet, it may be placed in the middle. As the use of the cross sections
before mentioned gives a greatly increased current effect, it allows of the use of
larger openings of the steam blast with reduction of back pressure and increase of
effect of the steam engine especially of a locomotive.
"
With compressed air, a wind chest of suitable size may be inserted and filled
with compressed air. This chest being shut off when sufficiently charged with air
under pressure may then be used for the slow action of producing air currents for
the apparatus until the pressure is used up.
In employing this system for ventilation purposes, in the ceiling of the room to
be ventilated, is placed a large pipe provided along its whole length with little
bound or deformed openings or similar small nozzles so that the air rushing in mixes
with the air of the room and is warmed. A second parallel pipe with a similar
series of large round openings carries off the foul air into the open or into a flue

page_text: or chamber. The above described pressure blast apparatus may be placed in this
pipe and set in action.
The jet apparatus described is especially suitable for transferring the temperature
of a gas or of a fluid to another, thus for the cooling or heating of air by means of
water, for the condensation of steam by water jets, or conversely for the cooling of
warm streams of water by means of the air drawn in, in place of step coolers, the
gas or liquid material under pressure or driven by pressure being caused to act by
suction on the finid to be drawn in.
The deformed shape of jet openings described in the second paragraph may also
be used with good effect in various jet pumps, steam injectors, jet blasts, apparatus
for carrying along solid matters etc. The various forms and constructions used up
till now would remain unaltered only the shape of cross section of the opening for
the passage of the driving fluid will be altered in the manner stated.
In ventilation and the drawing off of smoke, etc., the gases drawn off are often
hemmed or stemmed in their outflow or exit by adverse winds. To remove this
inconvenience special additions or chimney heads are used.
Here the method described in the first two paragraphs may be employed, adjoining
to the end of the flue a movable bent pipe made as far as possible flat in cross section,
oval, or rectangular with two long and two short sides or star shaped or otherwise
with its cross section formed as described in the second paragraph. The circular
form is only to be used with small cross sections in which the avoiding of the
formation of a dead centre need not be attended to. These movable pipes are
provided on the convex side of the curve or knee which meets the current of wind
with a divider which causes the wind to pass to each side of the pipe without
appreciable opposition and so arrive with full force near the mouth of the pipe so
that the full drawing power of the jet may be operative all round the mouth from
which the air to be exhausted issues (Fig. 7).
When large quantities of gases are to be drawn out several such flue additions or
chimney heads are used.
If we place in a current of air, gas, or water a pipe with its mouth lying in the
direction to which the current is flowing, a vacuum is formed in front of the mouth
of the pipe which draws upon the contents of the pipe. In this case we have a
condition actually contrary to that previously described herein. The actuating
current surrounds the pipe in which a suction is to be produced and the volume of
the actuating current is greater than the derived current. This is the case with
chimney cowls and the like of the "lobster back" pattern. In applying my
invention to that purpose the movable bent pipe, chimney head or cowl is made as
far as possible flat in cross section, oval or rectangular, with two long and two
short sides or star shaped or otherwise with the sections of the deformed shape
before described. The circular form is only to be used with small cross sections
in which the avoiding of the formation of a dead centre need not be
attended to.
These movable pipes are provided on the side which meets the current of wind
with a divider which causes the wind to pass to each side of the pipe without
appreciable opposition and so arrive with full force near the mouth of the pipe so
that the full drawing power of the current may be operative round the mouth from
which the air or smoke etc., to be exhausted issues.
When large quantities of gases are to be drawn out several such additions
are used.
In the last case the formation of the parts is changed, the drawing fluid is
outside surrounding the fluid to be driven, sucking it up and carrying it along. I
proceed in the same way in all cases when the bulk of the driving fluid is greater
than that to be driven, amplifying as much as possible the circumference of the
openings by the aid of the aforesaid sections and multiplication of openings.
The advantages of the apparatus are the following :—
1. Departing from very small forms their enlargement or multiplying provides a
corresponding increase in their efficiency.

page_text: more complete utilization of the latter.
3. They may be easily adapted for high or low pressure by altering the section
of the outlet.
4. The apparatus is exceedingly simple and therefore cheap, even the most
complete.
5. The apparatus does not easily wear out is light to support and easily
cleaned.
6. It is easily constructed in various materials and may be put together
readily.
7. It provides for the carrying out of draughtless ventilation at the smallest
cost.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
In fluid current producing apparatus or injectors
1. Nozzles with flat, oval, ogival, elliptic, semi-circular, triangular, quadrangular,
pentagonal or other polygonal section or of star shape or of any curved form of
opening or of narrow slit like or cross slit like mouths; the same being of very
small size according to the pressure of the driving fluid; those of 0-2 to 1 sq.m
area of section being conical with round or oval orifices for the purpose of increasing
the contact of the matters to be sucked in or thrown out.
2. The central arrangement of one and equal distribution of several nozzles
over the whole section of the outflow pipe without intermediate walls or division
chambers.
3. Short divergent conical additional pipes to the above named nozzles for the
concentrating of the currents.
4. The construction of the nozzles as plug cones for facility of changing and
cleaning and the combination with the feed pipes of fine sieves or washing apparatus
inserted therein.
5. Roses with openings of the forms described in Claim 1 or with nozzles of the
same form of mouth.
6. A wind-chest inserted between the stop-cock of the supply-pipe and the
openings of the blast pipes, for the purpose of cleansing the openings after the
closing of the stop-cock by the action of the compressed air accumulated in the said
air chest.
7. The combination of long pipes with small round or deformed openings for
feed of air, with other pipes with large openings for carrying off the air into the
open or into a chamber with or without the above current producing apparatus.
8. Current producing apparatus with steam or compressed air for air heating.
apparatus, regulating the delivery of the hot air constructed as herein described.
9. In the employment of this apparatus for the removal of smoke and gaseous
products of combustion and of hot air, the combination with the apparatus
described of heating worms or the like for the warming of the pressure fluid.
10. The construction of apparatus for the employment of exhaust steam or
residual gases of gas engines, for ventilation or for cooling the cylinder thereof in
the latter case by drawing in air.
11. In two or more cylinder engines a separated exhaust, also further division of
the steam blast into a large number of blast pipes of deformed cross sections, as
above set forth, in all cases with equivalent enlargement of the outlet cross section
in relation to the increase of the circumference of the current.
12. The construction of apparatus as described in Claims 1, 2, 3, 4 and 5 for
the cooling or heating of gases or liquids especially for the cooling of air, con-
densation of steam and for the cooling of the water used for cooling by means of
cold air.
13. The construction of the forms of section described in Claim 1 for the jet

page_text: openings of jet pumps, jet blasts especially of steam blasts and apparatus for the
removal of solid matters, such as grain, sand, etc.
14. The rotary flue tops or chimney heads of the forms described above with a
divider turned to the wind.
Dated this 8th dox of Aromet 1800
HERBERT & Co.,
18, Buckingham Street, Strand, London, W.C., Agents to Applicant.