Improvements in Nozzles for Use in Injecting Air in Ventilating and for other Purposes.
Year: 1886

page_text: This Specification was, upon the 27th day of January 1888, amended under
Sections 18 to 21 of the Patents, Designs, and Trade Marks Act, 1883.
Improvements in Nozzles for Use in Injecting Air in Ventilating
and for other Purposes.
We HENRY FRANCIS GREEN of 91 Queen Victoria Street in the City of London,
Engineer, and ALBERT WILLIAM PAUL STERKMAN of the Hague in the Kingdom
of Holland, Iron Merchant and of 91 Queen Victoria Street aforesaid, trading
together as the firm of "Green & Sterkman" Ventilating Engineers and Contractors
do hereby declare the nature of our invention for IMPROVEMENTS IN NOZZLES FOR
USE IN INJECTING AIR IN VENTILATING AND FOR OTHER PURPOSES to be as follows:-
This invention has reference to certain improvements in the construction of
apparatus of the character of that described in the Specification of Letters Patent
granted to one Alexander Melville Clark dated November 6th 1879 No. 4536 (on a
communication made to him from abroad by David Culver Green, father of the
present applicant Henry Francis Green and since deceased) for producing blasts or
currents of air for ventilation or other purposes by the injective action of jets of
steam or compressed air discharged from nozzles into suction throats or tubes.
According to our present invention we avoid disturbance of the direction of the
current of air supplied to the interior of the injector valve or nozzle and increase
the freedom of delivery by suppressing the branch or coupling or inlet at the side of
the casing marked A in the drawings to the said former Specification and in place
thereof we supply air directly in line with the axis of the delivery or approximately so.
Again, we dispense with the spring and case in its rearwardly projecting position as
described in the aforesaid Specification and in lieu thereof we centre the nozzle end
on a spindle or bearing stem borne on a cross arm or part in the casing and this
spindle passes into the nozzle end wherein also we locate the spring or springs, the

page_text: compression of which between nozzle end and a nut or holding parts on its spindle,
by its extent determines the extent of annular opening accorded to the issuant stream
of air and this extent of present compression is determinable by adjustment.
The elongated tapering portion or outer extremity of the valve plug or nozzle end
may be formed to slide or screw onto, into, or against the part which fills and closes
the aperture of the nozzle and these parts may be locked by a screw or like means
when together or home and the whole plug be screwed by the spindle socket
removably to the cross bearing in the shell.
Dated this 14th day of July 1886.
WM. BROOKES & SON.
55 & 56, Chancery Lane, London,
Agents for the said Henry Francis Green
and Albert William Paul Sterkman.
COMPLETE SPECIFICATION (AMENDED).
Improvements in Nozzles for Use in Injecting Air in Ventilating
and for other Purposes.
We HENRY FRANCIS GREEN of 91 Queen Victoria Street in the City of London,
Engineer, and ALBERT WILLIAM PAUL STERKMAN of the Hague in the Kingdom of
Holland, Iron Merchant and of 91 Queen Victoria Street aforesaid, trading together
as the firm of "Green & Sterkman" Ventilating Engineers and Contractors, 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 has reference to certain improvements in the construction of
apparatus of the character of that described in the Specification of Letters Patent
granted to one Alexander Melville Clark dated November 6th 1879 No. 4536 (on a
communication made to him from abroad by David Culver Green, father of the
present applicant Henry Francis Green and since deceased) for producing blasts or
currents of air for ventilation or other purposes by the injective action of jets of
steam or compressed air discharged from nozzles into suction throats or tubes.
According to our present invention we avoid disturbance of the direction of the
current of air supplied to the interior of the injector valve or nozzle and increase the
freedom of delivery by suppressing the branch or coupling or inlet at the side of
the casing marked A in the drawings to the said former Specification and in place
thereof we supply air directly in line with the axis of the delivery or approximately so.
Again, we dispense with the ing and case in its rearwardly projecting position
.

page_text: as described in the aforesaid Specification and in lieu thereof we centre the nozzle
end on a spindle or bearing stein borne on a cross arm or part in the casing and this
spindle passes into the nozzle end wherein also we locate the spring or springs, the
compression of which between nozzle end and a nut or holding parts on its spindle,
by its extent determines the extent of annular opening accorded to the issuant stream
of air and this extent of present compression is determinable by adjustment.
The elongated tapering portion or outer extremity of the valve plug or nozzle end
may be formed to slide or screw onto, into, or against the part which fills and closes
the aperture of the nozzle and these parts may be locked by a screw or like means
when together or home and the whole plug be screwed by the spindle socket
removably to the cross bearing in the shell."
In applying jets of air or other fluid issuing from a nozzle for the purpose of
inducing currents of air or other fluid we have found by experience that the best
results as regards the volume induced with the least expenditure of the fluid and the
power of producing the same is obtained by means of a jet orifice of an improved
form whereby the velocity and pressure of the jet is maintained independent of
variation in the volume supplied to it from the compressing pump or other apparatus,
thus greatly increasing the effectiveness of the jet, and causing its effectiveness to at all
times correspond proportionately with the volume supplied, as hereinafter fully set forth.
In producing air currents or blasts by the injective or inducing action of jets, it
is necessary as is well known, that the jet be discharged under a positive pressure and
at a high velocity in order to obtain an effective inducing action. The pressure of
course mainly determines the velocity of the jet, and it is found that the best effect
is obtained with a jet of a certain pressure and velocity, which of course varies in
different cases: but when this point is determined in each case it cannot be much
departed from without serious loss.
The volume of the jet is of course another element in its effectiveness, will be also
maintained, and will correspond with its increase or decrease of volume, while if its
power and velocity be allowed to fall or vary much from the best determined point,
the increase in volume will give no corresponding effectiveness but will be mainly a
loss of power. Hence the main defects in air jet nozzles as heretofore constructed,
and which we are to overcome, is that they are formed with a discharge aperture of a
fixed and uniform area, so that to maintain the pressure and velocity of the jet up to
its point of greatest efficiency it is necessary that the compressing pump or other source
of supply form a constant volume corresponding to such pressure and velocity from
a jet of that area, and if the volume increase or decrease beyond this point the area
of the jet then of course becomes proportionately too small or too large, hence
causing the pressure and velocity of the jet to correspondingly decrease or increase,
and thus rendering its action inefficient.
Now the main feature of the present invention may be stated to consist in con-
structing the air jet nozzle with an automatic valve arranged to govern its discharge
aperture and loaded to open at a certain pressure, so that hence the jet is discharged
uniformly at this pressure, and should the supply to the jet decrease in volume the
valve will partly close to correspondingly reduce the area of the discharge aperture,
and thus maintain the uniform pressure and velocity of the jet, and should the volume
increase the valve will open wider thus discharging a jet of greater volume yet at
practically the same pressure, thus maintaining the efficiency of the jet under a
varying supply, causing the volume of the induced current to increase proportionately
as the volume of the inducing jet increases.
The valve consists of a plug which is arranged in the aperture of the nozzle end*
of the injector, and when quiescent fully closes said aperture, preventing any discharge
from the nozzle. The outer extremity of the valve plug is preferably of an elongated
tapering form; its middle, or that part which fills and closes the aperture of the nozzle,
is cylindrical to form a close fit for the nozzle aparture, while its inner part is also
tapering to form, as the valve is pressed out of if nozzle, an annular outlet which
increases in area in proportion to the distance it is pressed out, as will be readily
understood. The valve plug is guided centrally in the nozzle aperture by a spindle

page_text: secured to the bridge inside of the shell. The valve is provided with a spring placed
inside of it which bears upon the end of it, the other end of the spring is secured by
jam nuts by which it is adjusted. The valve plug is made in halves to enable the
spring to be placed in position and for adjusting the same.
The nozzle is connected to the air supply pipe preferably by a branch or coupling.
on the end of the casing, and for ordinary ventilating purposes the air is supplied to
the nozzle under a pressure of about lbs. to the square inch. For ventilating
purposes an air compressing pump would be employed drawing the air from the
apartment or other place to be ventilated, or from the external atmosphere, and
discharging the compressed air through a pipe terminating with several of the
improved nozzles arranged in ventilating passages leading into and out of the
apartment. These nozzles are may be arranged to discharge into contracted suction
throats m, m, as shown in Clark's specification No. 4536 A.D. 1879 and the drawing
Figure 3 thereto annexed through which a large volume of atmospheric air is thus
induced to flow into and out of the apartment by the injecting action of the jet, as will
be readily understood, and these throats are preferably made adjustable towards the
nozzle so as to obtain the best relative position thereof. If the valves of the injector
nozzles be now set to the regular pressure and the air pump D Figure 6 shewn in
Figure 3 of the specification above mentioned is put in motion the nozzle valves will
confine the air till it attains the desired pressure, when the valve will open allowing
the discharge of an energetic jet from the nozzle having the required velocity and
pressure to produce an effective inducing action, and thus cause a strong induced
current to flow through the suction throats with the inducing jet. Should however
the speed of the pump decrease rendering the supply to the nozzle less, or should it
increase rendering the supply greater, the nozzle valve will partly close or open
correspondingly, thus causing the volume of the jet to always correspond to the
volume of its supply, while its pressure and velocity are maintained practically
uniform, thus causing the jet to act to its greatest efficiency under the different
variations in volume, and producing under different volumes a corresponding and full
efficiency. By means of these automatically acting nozzles it is found that the volume
of the inducing jet being one-the volume of the induced current will be thirty-five,
thus practically obtaining from one pump the capacity of thirty five pumps induced
current will be about from 30 to 40 times greater than that of the inducing current, such
increased volumes varying according to the conditions under which the nozzles are worked.
The improved nozzle may of course be used for producing air blasts or currents for
other purposes than ventilation, and it will also be understood that in some cases the
nozzle may be supplied with live steam instead of compressed air, but the use of the
latter is more generally-contemplated. adapted for the purposes of ventilation.
The foregoing arrangement of valve plug being guided centrally by means of the
spindle secured to the bridge has no feathers or vanes outside of it, by which arrange-
ment the air or fluid discharge through the jet is not broken we sometimes prefer to
arrange the valve plug of the nozzle so as to discharge a central jet in place of
discharging an annular jet as in the preceding arrangement as shown by Figure 3
berein after described more in detail, in this case we reverse the action of the valve
plug which is guided centrally upon a spindle secured to the bridge in the shell of the
nozzle, the spring bears against the inside end of the valve plug, thereby closing the
aperture in the direction of the compressor or pump. If the air pump is started and
the proper pressure reached, the valve will be pressed back in the shell allowing the
air or fluid to pass round it and out of the central orifice. The spring is adjusted by
a nut fitted on to the spindle.

page_text: In Figure 1 A indicates the casing or body, 6 the nozzle end thereof, in the aperture
of which, as shown, is arranged a valve plug B which when quiescent fully closes said
aperture, preventing any discharge from the nozzle. is a bridge across the shell
into which is secured a central spindle. The valve plug B is guided centrally by the
spindle c. The spring rests on the bottom of the valve plug B and encircles the
guide 6 and is held in position by the nut d¹ the bolt e is screwed into the spindle c,
and jams the nut d'. The nut d' regulates the tension of the spring the valve plug is
made in halves connected together with a screw f. E is the inlet for the compressed
air from the compressor F an india rubber washer upon which the valve plug rests.
The figure 3 is a longitudinal drawing of an improved nozzle for delivering an air
or fluid discharge centrally instead of annularly. A is the shell or casing. B is the
valve plug. Cis the bridge into which the spindle c is secured; d is the nut which
is used for adjusting the spring. E is the inlet for the compressed air from the
compressor. F is the discharge. g is a screw that may be employed to prevent
escape of the part B from its chamber.
Having now particularly described and ascertained the nature of our said invention
and in what manner the same is to be performed we declare that what we claim is :-
1. The improved arrangements or constructions of parts of an injector nozzle for
producing blasts or currents of air constructed with an automatic valve arranged to
govern its discharge and adjustable by spring or weights to open and discharge the
jet at a certain determined pressure whereby the pressure and velocity of the jet is
maintained uniform under varying volumes and its efficiency thus rendered constant
and proportional to the volume supplied as shown and described in reference to
Figures 1 and 2.
2. The improved injector nozzle for producing blasts or currents of air operating
in the manner above described and constructed as shown in Figure 3.
Dated this 1st da
1000
WM. BROOKES & SON,
55 & 56, Chancery Lane, London,
Agents for the Applicants.
WM. BROOKES & SON,
55 & 56, Chancery Lane, London,
Agents for the Applicants.

page_text: Date of Application, 14th July, 1886.
Complete Left, 4th Mar., 1887.
Complete Accepted, 15th Apr., 1887.
Improvements in Nozzles for Use in Injecting Air in Ventilating
and for other Purposes.
We HENRY FRANCIS GREEN of 91 Queen Victoria Street in the City of London,
Engineer, and ALBERT WILLIAM PAUL STERKMAN of the Hague in the Kingdom
of Holland, Iron Merchant and of 91 Queen Victoria Street aforesaid, trading
together as the firm of "Green & Sterkman" Ventilating Engineers and Contractors
do hereby declare the nature of our invention for IMPROVEMENTS IN NOZZLES FOR
USE IN INJECTING AIR IN VENTILATING AND FOR OTHER PURPOSES to be as follows:-
This invention has reference to certain improvements in the construction of
apparatus of the character of that described in the Specification of Letters Patent
granted to one Alexander Melville Clark dated November 6th 1879 No. 4536 (on a
communication made to him from abroad by David Culver Green, father of the
present applicant Henry Francis Green and since deceased) for producing blasts or
currents of air for ventilation or other purposes by the injective action of jets of
steam or compressed air discharged from nozzles into suction throats or tubes.
According to our present invention we avoid disturbance of the direction of the
current of air supplied to the interior of the injector valve or nozzle and increase
the freedom of delivery by suppressing the branch or coupling or inlet at the side of
the casing marked A in the drawings to the said former Specification and in place
thereof we supply air directly in line with the axis of the delivery or approximately so.
Again, we dispense with the spring and case in its rearwardly projecting position as
described in the aforesaid Specification and in lieu thereof we centre the nozzle end
on a spindle or bearing stein borne on a cross arm or part in the casing and this
spindle passes into the nozzle end wherein also we locate the spring or springs, the

page_text: compression of which between nozzle end and a nut or holding parts on its spindle,
by its extent determines the extent of annular opening accorded to the issuant stream
of air and this extent of present compression is determinable by adjustment.
The elongated tapering portion or outer extremity of the valve plug or nozzle end
may be formed to slide or screw onto, into, or against the part which fills and closes
the aperture of the nozzle and these parts may be locked by a screw or like means
when together or home and the whole plug be screwed by the spindle socket
removably to the cross bearing in the shell."
Dated this 14th day of Tul 1000
WM. BROOKES & SON,
55 & 56 Chancery Lane, London,
Agents for the said Henry Francis Green
and Albert William Paul Sterkman.

page_text: We HENRY FRANCIS GREEN of 91 Queen Victoria Street in the City of London,
Engineer, and ALBERT WILLIAM PAUL STERKMAN of the Hague in the Kingdom of
Holland, Iron Merchant and of 91 Queen Victoria Street aforesaid, trading together
as the firm of "Green & Sterkman" Ventilating Engineers and Contractors, 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 has reference to certain improvements in the construction of
apparatus of the character of that described in the Specification of Letters Patent
granted to one Alexander Melville Clark dated November 6th 1879 No. 4536 (on a
communication made to him from abroad by David Culver Green, father of the
present applicant Henry Francis Green and since deceased) for producing blasts or
currents of air for ventilation or other purposes by the injective action of jets of
steam or compressed air discharged from nozzles into suction throats or tubes.
According to our present invention we avoid disturbance of the direction of the
current of air supplied to the interior of the injector valve or nozzle and increase the
freedom of delivery by suppressing the branch or coupling or inlet at the side of
the casing marked A in the drawings to the said former Specification and in place
thereof we supply air directly in line with the axis of the delivery or approximately so.
Again, we dispense with the spring and case in its rearwardly projecting position
as described in the aforesaid Specification and in lieu thereof we centre the nozzle
end on a spindle or bearing stem borne on a cross arm or part in the casing and this
spindle passes into the nozzle end wherein also we locate the spring or springs, the
compression of which between nozzle end and a nut or holding parts on its spindle,
by its extent determines the extent of annular opening accorded to the issuant stream
of air and this extent of present compression is determinable by adjustment.
The elongated tapering portion or outer extremity of the valve plug or nozzle end
may be formed to slide or screw onto, into, or against the part which fills and closes
the aperture of the nozzle and these parts may be locked by a screw or like means
when together or home and the whole plug be screwed by the spindle socket
removably to the cross bearing in the shell.
In applying jets of air or other fluid issuing from a nozzle for the purpose of
inducing currents of air or other fluid we have found by experience that the best
results as regards the volume induced with the least expenditure of the fluid and the
power of producing the same is obtained by means of a jet orifice of an improved

page_text: form whereby the velocity and pressure of the jet is maintained independent of
variation in the volume supplied to it from the compressing pump or other apparatus,
thus greatly increasing the effectiveness of the jet, and causing its effectiveness to at all
times correspond proportionately with the volume supplied, as hereinafter fully set forth.
In producing air currents or blasts by the injective or inducing action of jets, it
is necessary as is well known, that the jet be discharged under a positive pressure and
at a high velocity in order to obtain an effective inducing action. The pressure of
course mainly determines the velocity of the jet, and it is found that the best effect
is obtained with a jet of a certain pressure and velocity, which of course varies in
different cases; but when this point is determined in each case it cannot be much
departed from without serious loss.
The volume of the jet is of course another element in its effectiveness, will be also
maintained, and will correspond with its increase or decrease of volume, while if its
power and velocity be allowed to fall or vary much from the best determined point,
the increase in volume will give no corresponding effectiveness but will be mainly a
loss of power. Hence the main defects in air jet nozzles as heretofore constructed,
and which we are to overcome, is that they are formed with a discharge aperture of a
fixed and uniform area, so that to maintain the pressure and velocity of the jet up to
its point of greatest efficiency it is necessary that the compressing pump or other source
of supply form a constant volume corresponding to such pressure and velocity from
a jet of that area, and if the volume increase or decrease beyond this point the area
of the jet then of course becomes proportionately too small or too large, hence
causing the pressure and velocity of the jet to correspondingly decrease or increase,
and thus rendering its action inefficient.
Now the main feature of the present invention may be stated to consist in con-
structing the air jet nozzle with an automatic valve arranged to govern its discharge
aperture and loaded to open at a certain pressure, so that hence the jet is discharged
uniformly at this pressure, and should the supply to the jet decrease in volume the
valve will partly close to correspondingly reduce the area of the discharge aperture,
and thus maintain the uniform pressure and velocity of the jet, and should the volume
increase the valve will open wider thus discharging a jet of greater volume yet at
practically the same pressure, thus maintaining the efficiency of the jet under a
varying supply, causing the volume of the induced current to increase proportionately
as the volume of the inducing jet increases.
The valve consists of a plug which is arranged in the aperture of the nozzle end
of the injector, and when quiescent fully closes said aperture, preventing any discharge
from the nozzle. The outer extremity of the valve plug is preferably of an elongated
tapering form; its middle, or that part which fills and closes the aperture of the nozzle,
is cylindrical to form a close fit for the nozzle aperture, while its inner part is also
tapering to form, as the valve is pressed out of the nozzle, an annular outlet which
increases in area in proportion to the distance it is pressed out, as will be readily
understood. The valve plug is guided centrally in the nozzle aperture by a spindle
secured to the bridge inside of the shell. The valve is provided with a spring placed
inside of it which bears upon the end of it, the other end of the spring is secured by
jam nuts by which it is adjusted. The valve plug is made in halves to enable the
spring to be placed in position and for adjusting the same.
The nozzle is connected to the air supply pipe preferably by a branch or coupling
on the end of the casing, and for ordinary ventilating purposes the air is supplied to
the nozzle under a pressure of about 5 lbs. to the square inch. For ventilating
purposes an air compressing pump would be employed drawing the air from the
apartment or other place to be ventilated, or from the external atmosphere, and
discharging the conipressed air through a pipe terminating with several of the
improved nozzles arranged in ventilating passages leading into and out of the
apartment. These nozzles are arranged to discharge into contracted suction
throats m, m, through which a large volume of atmospheric air is thus induced to
flow into and out of the apartment by the injecting action of the jet, as will be
readily understood, and these throats are preferably made adjustable towards the

page_text: nozzle so as to obtain the best relative position thereof. If the valves of the injector
nozzles be now set to the regular pressure and the air pump D Figure 6 is put in
motion the nozzle valves will confine the air till it attains the desired pressure, when
the valve will open allowing the discharge of an energetic jet from the nozzle having
the required velocity and pressure to produce an effective inducing action, and thus
cause a strong induced current to flow through the suction throats with the inducing.
jet. Should however the speed of the pump decrease rendering the supply to the
nozzle less, or should it increase rendering the supply greater, the nozzle valve will
partly close or open correspondingly, thus causing the volume of the jet to always
correspond to the volume of its supply, while its pressure and velocity are maintained
practically uniform, thus causing the jet to act to its greatest efficiency under the
different variations in volume, and producing under different volumes a corre-
sponding and full efficiency. By means of these automatically acting nozzles it is
found that the volume of the inducing jet being one the volume of the induced
current will be thirty five, thus practically obtaining from one pump the capacity of
thirty five pumps. The improved nozzle may of course be used for producing air
blasts or currents for other purposes than ventilation, and it will also be understood
that in some cases the nozzle may be supplied with live steam instead of compressed
air, but the use of the latter is more generally contemplated.
The foregoing arrangement of valve plug being guided centrally by means of the
spindle secured to the bridge has no feathers or vanes outside of it, by which arrange-
ment the air or fluid discharge through the jet is not broken we sometimes prefer to
arrange the valve plug of the nozzle so as to discharge a central jet in place of
discharging an annular jet as in the preceding arrangement as shown by Figure 3
herein after described more in detail, in this case we reverse the action of the valve
plug which is guided centrally upon a spindle secured to the bridge in the shell of the
nozzle, the spring bears against the inside end of the valve plug, thereby closing the
aperture in the direction of the compressor or pump. If the air pump is started and
the proper pressure reached, the valve will be pressed back in the shell allowing the
air or fluid to pass round it and out of the central orifice. The spring is adjusted by
not fitted on to the aninda
Figure 1 in the accompanying drawings is a longitudinal section and Figure 2
is a plan view of the improved air injector nozzle, Figure 3 is a modification of it,
and is a longitudinal drawing of a nozzle showing the mode in which a central jet of
air or fluid is delivered.
In Figure 1 A indicates the casing or body, 6 the nozzle end thereof, in the aperture
of which, as shown, is arranged a valve plug B which when quiescent fully closes said
aperture, preventing any discharge from the nozzle. C is a bridge across the shell
into which is secured a central spindle. The valve plug B is guided centrally by the
spindle c. The spring rests on the bottom of the valve plug B and encircles the
guide band is held in position by the nut d¹ the bolt e is screwed into the spindle c,
and jams the nut d'. The nut d regulates the tension of the spring the valve plug is
made in halves connected together with a screw f. E is the inlet for the compressed
air from the compressor F an india rubber washer upon which the valve plug rests.
The figure 3 is a longitudinal drawing of an improved nozzle for delivering an air
or fluid discharge centrally instead of annularly. A is the shell or casing. B is the
valve plug. C is the bridge into which the spindle c is secured; d is the nut which
is used for adjusting the spring. E is the inlet for the compressed air from the
compressor. F is the discharge. g is a screw that may be employed to prevent
escape of the part B from its chamber.
Having now particularly described and ascertained the nature of our said invention
and in what manner the same is to be performed we declare that what we claim is :-
1. The improved arrangements or constructions of parts of an injector nozzle for

page_text: producing blasts or currents of air constructed with an automatic valve arranged to
govern its discharge and adjustable by spring or weights to open and discharge the
jet at a certain determined pressure whereby the pressure and velocity of the jet is
maintained uniform under varying volumes and its efficiency thus rendered constant
and proportional to the volume supplied as shown and described in reference to
Figures 1 and 2.
2. The improved injector nozzle for producing blasts or currents of air operating
in the manner above described and constructed as shown in Figure 3.
Dated this 1st day of March 1887.
WM. BROOKES & SON,
55 & 56, Chancery Lane, London,
Agents for the Applicants.
WM. BROOKES & SON,
55 & 56, Chancery Lane, London,
Agents for the Applicants.