IMPROVEMENTS IN APPARATUS FOR INCREASING THE DRAFT IN CHIMNEYS OR FUNNELS, FOR PROPELLING FRESH AIR INTO THE STOKE HOLES OR STOKE ROOMS OF STEAM SHIPS, AND FOR VENTILATING PURPOSES GENERALLY
Year: 1879

page_text: LETTERS PATENT to John Clayton Mewburn, of 169, Fleet Street, in the City
of London, Patent Agent and Consulting Engineer, for the Invention of
"IMPROVEMENTS IN APPARATUS FOR INCREASING THE DRAFT IN CHIMNEYS
OR FUNNELS, FOR PROPELLING FRESH AIR INTO THE STOKE HOLES OR STOKE
ROOMS OF STEAM SHIPS, AND FOR VENTILATING PURPOSES GENERALLY." A
communication from abroad by Alexander Friedmann, of Vienna, in the
Empire of Austria, Engineer.
ealed the 24th October 1879, and dated the 29th April 1879.
PROVISIONAL SPECIFICATION left by the said John Clayton Mewburn at
the Office of the Commissioners of Patents on the 29th April 1879.
JOHN CLAYTON MEWBURN, of 169, Fleet Street, in the City of London, Patent
Agent and Consulting Engineer. "IMPROVEMENTS IN APPARATUS FOR INCREASING
THE DRAFT IN CHIMNEYS OR FUNNELS, FOR PROPELLING FRESH AIR INTO THE
STOKE HOLES OR STOKE ROOMS OF STEAM SHIPS, AND FOR VENTILATING PURPOSES
GENERALLY." [A communication from abroad by Alexander Friedmann, of Vienna,
in the Empire of Austria, Engineer.]
This Invention has for its objects in the first place improvements in the
apparatus described and illustrated in the Specification and Drawings of former
Letters Patent dated the 16th day of November 1878, No. 4661, and secondly, the
adaptation and application of the said apparatus to other uses or purposes.
In the aforesaid Specification and especially in Figure 9 of the Drawings
annexed thereto there is described and shewn an apparatus which carries out a
new constructive principle, and is in fact quite a new body or object. The said
apparatus has however certain defects which it is one object of the present
improvements to overcome.
In the aforesaid Specification the apparatus was based on the idea that nearly all
the smoke or combustion gases are to pass through what I therein call the suction
cone e, and therefore the diameter of the prolongation of this said suction cone e or
of the annular orifice was to have a diameter nearly equal to that of the chimney,,
D

page_text: and was in fact in the said Figure 9 shewn as having about six sevenths or five
sixths of the diameter of the chimney. But it has since been discovered that what
was then considered the chief purpose, that is, to have a blast apparatus with an
annular orifice of the same or nearly the same diameter as the chimney is not of so
great an importance, and that on the contrary it is better to have the apparatus
shewn in Figure 9 of the aforesaid Patent so formed that the inner diameter of the
annular orifice (which is formed by the outer diameter of the prolongation of the
suction cone) be only three fourths or two thirds of the diameter of the chimney,
and that even with a smaller size the apparatus works still much better than
ordinary blast pipes, or blast pipes which have only an ordinary annular orifice.
It has also been discovered that the effect of the apparatus is increased especially
when the diameter of its annular orifice is made less than three sevenths or one
half of the diameter of the chimney, by interposing between the blast apparatus
and the chimney an intermediate chimney, so that the blast apparatus similar to
Figure 9 works first in the intermediate chimney and then in the real chimney,
and that this interposing of an intermediate chimney is chiefly useful in very large
chimuies, and when the apparatus is to be used only instead of the ordinary blasts.
This interposing of an intermediate chimney is useful even in combination with
an ordinary annular orifice of blast pipes. The prolongation of what I call the
suction cone of the apparatus, Figure 9 of the aforesaid Specification, also works
much better if it is longer than is shewn in the said Figure 9, and the apparatus
is much improved if this prolongation is nearly as great or even greater than its
diameter. The details of the construction of the said apparatus shewn in Figure 9
of the said Specification have also been improved, so that the parts which together
form the blast apparatus can be better fitted together than is shewn in Figure 9
of the aforesaid Patent so as to be very air tight, and at the same time be made
more cheaply. And lastly, concerning this Figure 9 of the aforesaid Patent it has
also been improved so as to adapt it to chimneys or funnels of those steamers
or engines, where the exhaust steam passes into the condensers so as to be more
successfully worked by compressed air. In fact the apparatus as shewn in
Figure 9 was practically admissible only in the smoke box of locomotive or
similar boilers because when inserted into the chimney of a steamer it would
by the shape and dimensions of its casing have too much obstructed the chimney,
whereas now the outer diameter of the whole apparatus or of the casing m of
the said Figure 9 is made much smaller; a more cylindrical shape is given to
this casing so that even when inserted directly into the chimney it does not
form there a serious obstruction; besides it is always provided that even with
the blast apparatus having the outer diameter of the casing m so large as in
Figure 9 of the aforesaid Specification, the part of the chimney where the appa-
ratus is to be placed is enlarged in such a way that the total area of the passage
of the smoke around the casing and through the prolongation of the suction cone
The same
is large enough to prevent any contraction or obstruction being formed.
improvements as relate to the apparatus shewn in Figure 9 of the aforesaid Patent
also apply to the apparatus shewn in Figures 8 and 11 of the same Patent,
and although the apparatus, Figure 9, when improved in the manner herein-
before described is considered to be the best, still the improvements of the
apparatus, Figures 8 and 11 of the aforesaid Patent, have the effect of render-
ing it more valuable than hitherto, both when worked with the exhaust steam
from the engine cylinders and when worked with compressed air, and not
only for locomotives, portable engines, and steam ships, but also for all sorts of
funnels. But with all the apparatus, both those of the aforesaid Patent and the
improved apparatus herein described, several problems of ventilation can be more
successfully solved. In the first place it has often been contemplated to supply
more air into the stoke room of steam ships, but the quantity of air thus required
being very large it would with the existing methods require very large and
voluminous and slowly working fans. According to the present Invention I
establish an ordinary fan with quick rotation, thus compressing a moderate quantity

page_text: of air to the usual pressure of 21% to 4 inches. I lead this air through an air
channel to a blast pipe inserted in the air funnel of the stoke room, and so that the
compressed air from the said blast pipe escapes in the direction towards the stoke
room and draws with it a large quantity of air and propels it into the stoke room.
Whatever be the type of the blast pipe this method will prove very useful both for
the combustion and for the fire men, and the increase in the supply or descent of
air into the stoke room by establishing an ordinary fan driving the compressed air
to a blast pipe inserted in the air funnel is in itself of great practical importance,
and new, whatever be the special construction of the blast pipe, but naturally this
method is better carried into effect by making the blast apparatus according to one
of the constructions described in the Specification of the said Letters Patent of 10th
November 1878, and carried into effect in the best way by making the blast
apparatus according to the improved construction herein described.
The improved blast apparatus, and especially those of the present improved con-
struction, are also very useful for all such purposes of ventilation in which it is
required to propel a great quantity of air with very small pressure, as in the shafts
of coal or other mines, or as in breweries, sugar factories, distilleries, etc., to cool the
mash, sugar juice, etc. In all these cases I supply by an ordinary fan compressed
air to my blast apparatus which is then specially adapted so that the compressed
air arriving from the fan takes up a large quantity of fresh air and propels it into
the pit, or shaft, or space to be ventilated.
As generally ventilation by propelling fresh air is much to be preferred to
ventilation by exhaustion, the improved apparatus last herein described will prove
very useful; but also in cases when the ventilation is to be made by exhaustion, as
in some mine shafts, the blast apparatus can be fitted in a similar way to that
followed for increasing the draft of chimneys, and it is then possible also to work
my blast apparatus not only by fans but also by ejectors.
Lastly, an air shaft is also constructed which may be useful especially when com.
bined with my blast apparatus. This air shaft is chiefly intended to be used on
board steamers to ventilate the stoke room at those times when the state of the
atmosphere may be favorable enough to save working the fan and blast apparatus.
The construction of the said air shaft is essentially based on the principle that it is
a double one, being one shaft inside the other, the one to bring the fresh air down
to the stoke room, and the other to take up the hot air from the stoke room, so that
the fresh air coming down meets the hot air when this latter enters the shaft, and
so that near the lower ends of the two concentric shafts in the stoke room there are
formed eddies of the fresh and the warm air, thus the fresh air does not (as is now
generally the case) come down directly and in a strong current upon the head and
neck of the firemen working under or near the air shaft. Moreover that one of the
two concentric shafts which takes up the warm air is provided in front with a sort
of ejector worked by the wind so as to increase the draft of this said shaft.
As I have already stated it is proposed chiefly to use this self acting air shaft
rather as an auxiliary of the blast apparatus, because very often the state of the
atmosphere is such that this new air shaft would not be of much assistance, and
then the improved blast apparatus would be of great use. But on the other hand
the new air shaft is so much better than the existing or ordinary air shafts that in
cases where the costs of a fan and blast apparatus would not be incurred, or in
sailing ships where there is no steam to work a fan, or even in other places to be
ventilated only by the natural action of the wind, as breweries, distilleries, and
other places, the new air shaft would prove of a much better effect than the existing
one.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Clayton Mewburn in the Great Seal Patent Office on the 28th
October 1879.
JOHN CLAYTON MEWBURN, -of 169, Fleet Street, in the City of London, Patent
Agent and Consulting Engineer. "IMPROVEMENTS IN APPARATUS FOR INCREASING
THE DRAFT IN CHIMNEYS OR FUNNELS, FOR PROPELLING FRESH AIR INTO THE
STOKE HOLES OR STOKE ROOMS OF STEAM SHIPS, AND FOR VENTILATING PURPOSES
GENERALLY." (A communication from abroad by Alexander Friedmann, of Vienna,
in the Empire of Austria, Engineer.)
This Invention has for its objects, in the first place, improvements in the apparatus
described and illustrated in the Specification and Drawings of former Letters Patent,
dated the 16th day of November 1878, No. 4661, and, secondly, the adaptation and
application of the said apparatus to other uses or purposes.
In the aforesaid Specification, and especially in Figure 9 of the Drawings annexed
thereto, there is described and shewn an apparatus which carries out a new con-
structive principle, and is in fact quite a new body or object. The said apparatus
hus however certain defects, which it is one object of the present improvements to
overcome.
In the aforesaid Specification the apparatus was based on the idea that nearly all
the smoke or combustion gases are to pass through what is therein called the suction
cone, and therefore the diameter of the prolongation of this said suction cone, or of
the annular orifice, was to have a diameter nearly equal to that of the chimney,
and was in fact in the said Figure shewn as having about six sevenths or five
sixths of the diameter of the chimney. But it has since been discovered that what
was then considered the chief purpose, that is, to have a blast apparatus with an
annular orifice of the same or nearly the same diameter as the chimney, is not of so
great an importance, and that, on the contrary, it is better to have the apparatus of
the aforesaid Patent so formed that the inner diameter of the annular orifice (which
is formed by the outer diameter of the prolongation of the suction cone) may be
only three fourths or two thirds of the diameter of the chimney, and that even with
a smaller size the apparatus works still much better than ordinary blast pipes or
blast pipes which have only an ordinary annular orifice. It has also been discovered
that the prolongation of what is called the suction cone works much better if it is
made longer than shewn in the Drawings of the aforesaid Patent, and the apparatus
works much better if this prolongation be made, as shewn at e, e, in Figure 1 of the
Drawings hereunto annexed, as long as (reckoning from the annular orifice) or even
longer than its diameter. It has further been discovered that the effect of the
apparatus is increased especially when the diameter of its annular orifice is made
less than one half of the diameter of the chimney, by interposing between the blast
apparatus and the chimney an intermediate chinney, as shewn at z, z, in Figure 2
of the Drawings hereunto annexed, so that the blast apparatus e, e, works first in
the intermediate chimney z, z, and then in the real chimney. This interposing of an
intermediate chimney is chiefly useful in very large chimnies, and even in combina-
tion with blast pipes having an ordinary annular orifice. The details of the construc-
tion of the apparatus have also been improved, so that the parts which together form
the blast apparatus can be better fitted together than hitherto, so as to be very air
tight, and at the same time be made more cheaply. Thus, in the arrangement shewn
in Figure 1 of the Drawings hereunto annexed, the part e, e, is connected by hori-
zontal joints to the casing m, m; in Figure 2 the part e, e, is shewn as cast in one
piece with the casing of the apparatus, so that it is only necessary to add the piece m¹.
As it is this piece m¹ which is most subject to wear, the arrangement shewn in
Figure 2 is better than that shewn in Figure 1 so far as regards the fitting of the
parts together. Lastly, the apparatus has also been improved so as to adapt it to

page_text: chimneys or funnels of those steamers or engines where the exhaust steam passes
into the condenser so as to be more successfully worked by compressed air. In fact
the apparatus as shewn in the aforesaid Patent was practically admissible only in
the smoke box of locomotive or similar boilers, because when inserted into the
chimney of a steamer it would by the shape and dimensions of its casing have too
much obstructed the chimney, whereas now the outer diameter of the casing m is
made as shewn in Figures 4, 5, 6, and 7 of the Drawings hereunto annexed, much
smaller than before, and a more cylindrical shape is given to this casing, so that
even when inserted directly into the chimney it does not forin there a serious
obstruction. Further, it is also provide that the part of the chimney where the
apparatus is to be placed is enlarged, as shewn in Figure 7, in such a way that the
total area of the passage of the sinoke around the casing and through the prolonga-
tion of the suction cone is large enough not to cause any obstruction or contraction..
Figures 3 and 4 also shew an improvement of valve, especially where the diameter
of the annular orifice is much smaller than the diameter of the chimney, by giving
to the prolongation e, e, a conical form, so that the exhaust steam or compressed air
reaches the inner surface of the chimney more easily, and works well even in the
case of short chimneys.
In addition to improving the apparatus shewn in Figure 9 of the aforesaid
Patent I have also improved the apparatus shewn in Figure 8 of the same Patent,
so as to render it more valuable than hitherto both when worked with the exhaust
steam from the engine cylinders and when worked with compressed air, and not
only for locomotives, portable engines, and steam ships, but also for all sorts of
funnels. Thus Figure 2 of the Drawings hereunto annexed shews the part m made
easily removable, and the blast apparatus me, e, combined with an intermediate
chimney ; and Figure 6 shews an improvement which may be applied to all the
arrangements represented in the Drawings hereunto annexed, viz., a throttle valve
fitted into the part e, e, Figure 6, 7, or 5, so as to allow this part to be closed when
desired.
With all the apparatus, both those of the aforesaid Patent and the improved
apparatus herein described, several problems of ventilation can be more successfully
solved. In the first place it has often been contemplated to supply more air into.
the stoke room of steam ships. But the quantity of air thus required being very
large it would with the existing methods require very large and voluminous and
slowly working fans. According to the present Invention I establish an ordinary
fan with quick rotation, thus compressing a moderate quantity of air to the usual
pressure of 2 to 4 inches. I lead this air, as shewn at Figure X of the Drawings
hereunto annexed, through an air channel a to a blast pipe inserted in the hori-
zontal or vertical part of the air shaft of the stoke room, and so that the compressed
air from the said blast pipe escapes in the direction towards the stoke room, and
draws with it a large quantity of air, and propels it into the stoke room. What-
ever be the type of the blast pipe this method will prove very useful, both for the
combustion and for the firemen, and the increase in the supply or descent of air
into the stoke room by establishing an ordinary fan driving the compressed air
to a blast pipe inserted in the air shaft is in itself of great practical importance and
new, whatever be the special construction of the blast pipe, but this method is
carried into effect in the best way by making the blast apparatus according to the
improved construction described in this Specification.
The improved blast apparatus, and especially those of the present improved con-
struction are also very useful for all purposes of ventilation in which it is required
to propel a large quantity of air with very small pressure, as in the shafts of coal
or other mines, or as in breweries, sugar factories, distilleries, etc., to cool the mash,
sugar juice, etc. In all these cases I supply by an ordinary fan compressed air to
my blast apparatus, which is then specially adapted, as shewn in Figure V, so that
the compressed air arriving from the fan by the air pipe a takes up a large
quantity of fresh air and propels it into the part z, z, which discharges it into the

page_text: space to be ventilated, or is inserted in the pit or shaft when intended for pit or
air shafts.
As generally ventilation by propelling fresh air is much to be preferred to
ventilation by exhaustion the improved apparatus last herein described will prove
very useful.
But also in cases where the ventilation is to be made by exhaustion,
as in some mine shafts, the blast apparatus can be fitted in a similar way to that
followed for increasing the draft of chimneys, and it is then possible also to work my
blast apparatus not only by fans but also by ejectors.
Lastly. I construct an air shaft as shewn in Figure Y, which may be useful,
especially when combined with another air shaft of the form shewn in Figure X;
this air shaft (Figure Y) is chiefly intended to be used on board steamers to
ventilate the stoke room at those times when the state of the atmosphere may be
favorable enough to save working the fan and blast apparatus, Figure X. The
construction of the said air shaft is essentially based on the principle that it is a
double one, being one shaft inside the other; the one, o, to bring the fresh air down
to the stoke room, and the other, p, to take up the hot air from the stoke room, so
that the fresh air coming down through o melts the hot air when this latter enters
the shaft p, and so that near the lower ends of the two concentric shafts in the
stoke room there are formed eddies of the fresh and the warm air, thus the fresh
air does not (as is now generally the case) come down directly and in a strong
current upon the head and neck of the, firemen working under or near the air.
shaft. Moreover the shaft p which takes up the warm air is provided at the top
with a sort of ejector r worked by the wind, so as to increase the draft. As I have
already stated it is proposed chiefly to use this self acting air shaft, Figure Y,
rather as an auxiliary of the blast apparatus, Figure X, because very often the
state of the atmosphere is such that an air shaft like Figure Y would not be of
much assistance, and then the apparatus, Figure X, would be of great use.
on the other hand the air shaft, Figure Y, is so much better than the existing or
ordinary air shafts, that in cases where the cost of a fan and blast apparatus would
not be incurred, or in sailing ships where there is no steam to work a fau, or even
in other places to be ventilated only by the natural action of the wind, as breweries,
distilleries, and other places, the air shaft, Figure Y, would prove of much better
effect than the ordinary ones.
But
And having now described the nature of the said Invention, and in what manner
the same is to be performed, I declare that I claim,―
The several arrangements or combinations of parts, substantially as bereinbefore
described and shewn in the Drawings hereunto annexed, forming improved
apparatus for increasing the draft in chimneys or funnels, for propelling fresh air
into the stoke boles or stoke rooms of steam ships, and for ventilating purposes
generally, as herein set forth.
In witness whereof, I, the said John Clayton Mewburn, have hereunto set my
hand and seal, this Twenty eighth day of October, One thousand eight
hundred and seventy nine