IMPROVED MEANS FOR VENTILATING MINES SEWERS AND BUILDINGS
Year: 1884

page_text: I, WILLIAM HENRY CHAPMAN of Agnes Cottage, Ladywell, Lewisham in the
County of Kent, Clerk of Works do hereby declare the nature of my Invention
for IMPROVED MEANS FOR VENTILATING MINES SEWERS AND BUILDINGS to be as
follows:-
The object of the present Invention is to provide simple and efficient means for
inducing currents of air in shafts or chimneys suitable for the ventilation of mines,
tunnels, sewers and buildings.
The Invention consists in the combination with a chimney or shaft leading from
the tunnel room or passage to be ventilated of a series of ejector nozzles preferably
arranged in a circle towards the upper end of the shaft and connected by a pipe or
pipes with a pump, blower, or engine by which a fluid such as air is forced under
pressure out of the soveral ejector nozzles. The draught in the shaft or chimney
duo to natural variations in pressure will be greatly increased by the abovo
arrangement of ejector nozzles and this draught will be acclerated when a fire is
burning at the foot of or within the shaft or chimney. Suitable fresh air inlets are
provided in the rooms to be ventilated and the foul air may be drawn from a series
of rooms by a single shaft fitted with an annular compressed air ejector as above
described, suitable connections being made between the shaft and the several rooms
to bo ventilated.
In applying the Invention to the ventilation of sewers, I employ a shaft as in
the preceding example with a fire or furnace at its lower part and I adapt to its
upper end one or more ejectors each preferably consisting of an annular tube from
which a series of ejector nozzles project in lines converging towards a central point
or axis. I prefer to separate the products of combustion in the furnace from the
powerful ascending air and gas currents induced by the fire and the ejectors and
for this purpose I employ a closed furnace and carry such products off by a separate
flue. The foul air and sewer gases having to pass around the walls of the heated
furnace will be partially burnt and purified before escaping.
The same result is in part obtained in public buildings where open fire places are
used and the air being purer it is not so essential that it should be passed over fire
or against red hot metal or fire clay before escaping, but with sewer gas this is
most desirable.

page_text: The tubular base of the ejector may be readily adapted to the exterior of
chimney pots and take the form of a collar moulding the several ejector nozzles
being inserted obliquely through holes drilled in the chimney pot but in the case of
metal chimney pots I prefer to fit the ejectors inside.
I would remark that I do not limit myself to any particular machine or apparatus
for supplying air under pressuro to the ejector nozzles nor to any particular
description of engine for working such machine or apparatus; thus I may use a
fan or blower or double acting air compressor driven by a steam, gas, or hot air
engine.

page_text: I, WILLIAM HENRY CHAPMAN of Agnes Cottage, Ladywell, Lewisham in the
County of Kent, Clerk of Works do hereby declare the nature of my Invention
for IMPROVED MEANS FOR VENTILATING MINES, SEWERS AND BUILDINGS and in
what manner the same is to be performed, to be particularly described and
[ascertained in and by the following statement:—
The object of the present Invention is to provide simple and efficient means for
inducing currents of air in shafts or chimneys suitable for the ventilation of mines,
tunnels, sewers and buildings.
The Invention consists in the combination with a chimney or shaft leading from
the tunnel, room, or passage to bo ventilated, of an annular ejector, or a series of
ejector nozzles, preferably arranged in a circle at or towards the upper end of the
chimney shaft, the said annular ejector or series of ejector nozzles being connected
by a pipe or pipes with a pump, blower, ventilating cowl or engine, by which a
fluid such as air is forced under pressure out of the aperture of the annular ejector,
or the apertures of the several ejector nozzles. The draught in the shaft or
chimney due to natural variations in pressure will be greatly increased by such an
arrangement of air ejectors, and this up draught will be accelerated when a fire is
burning at the foot of, or within the shaft or chimney. Suitable fresh air inlets aro
provided in the rooms to be ventilated, and the foul air may be drawn from a
series of rooms by a single shaft fitted with an annular compressed air ejector, as
above described, suitable connections being made between the shaft and the several
rooms to be ventilated.
In applying the Invention to the ventilation of sewers, I employ a shaft, as in
the preceding example, with a fire or furnace at its lower part, and I adapt to its
upper end one or more ejectors, each preferably consisting of an annular tube
provided with a continuous narrow orifice or slit, or with a series of ejector nozzles
from which the air will be delivered in a stream or streams converging towards a
central point or axis. I prefer to separate the products of combustion in the
furnace from the powerful ascending air and gas currents induced by the fire and
the ejectors, and for this purpose I employ a closed furnace, and carry such
products off by a separate flue.. The foul air and sewer gases having to pass
around the walls of the heated furnace, will be partially burnt and purified before
escaping.
The same result is in part obtained in public buildings where open fire places
are used, and the air being purer, it is not so ossential that it should be passed over
fire, or against red hot metal or fire clay, before escaping, but with sewer gas this
is most desirable.
The tubular base of the ejector may be readily adapted to the exterior of
chimney pots, and take the form of a collar moulding, the continuous or narrow
orifice or slit being open to the interior of the chimney, or the several ejector
nozzles being inserted obliquely through holes formed in the chimney pot, but in
the caso of metal chimney pots, I prefer to fit the ejector or ejectors inside.
The Invention will be understood on reference to the accompanying Drawings,
in which Fig. 1 is a sectional elevation of a chimney pot fitted with an ejector for
inducing a draught according to my Invention.
Fig. 2 is a section on the line x x of Fig. 1.
Fig. 3 illustrates in sectional elevation the mode of adapting my Invention to

page_text: -
Fig. 4 is a sectional elevation of another mode of adapting my Invention to
existing chimneys.
Fig. 5 is a sectional elevation showing my Invention applied to the ventilation
of sewers in combination with a closed furnace for destroying the organisms
contained in the sewer gas as they are drawn up the shaft under the influence of
the ejector.
Fig. 6 is a vertical cross section on the lino y y of Fig. 5, and Fig. 7 is a plan on
the line of Fig. 5.
In all these Figures the same letters of reference indicate like or corresponding
parts.
Referring now to Figs. 1 and 2, A is the ejector formed by moulding in the
chimney pot B. The ejector A consists preferably of a tube bent into a circle, or
of an annular passage having a narrow continuous orifice or slit a in its inner wall,
the said orifice or slit being so situate with respect to the axis of the annular tube
or passage, that when air under pressure is forced through it, the jet or stream of
air issuing in the direction of the arrows bb will converge towards a point c, and
produce a vortex, inducing a steady upward draught in the chimney.
The ejector A might consist of a series of ejector nozzles having wide bases and
contracted mouths or orifices, as shown at Fig. 4, the said nozzles being arranged
in a circle, their bases being open to a common air supply tube, and their contracted
mouths pointing upwards and inwards. The effect produced is practically the
same, but I prefer to use the ejector with a continuous orifice or slit for the air,
mather than one composed of a series of separate nozzles, on account of its greater
simplicity in manufacture and convenience in fixing.
It will be seen from the plan view Fig. 2, that the tubular passage or base of the
annular ejector A is divided by a partition b', so that the air, which is forced under
pressure into the ejector A by means of a ventilating inlet cowl, such as C or by a
fan, air compressor or other suitable means, finding its passage in a circular path
barred, shall be expelled with great velocity, and with a certain degree of twist
through the continuous orifice or annular nozzle a.
.
The same result can be attained with a series of separate nozzles arranged in a
ring, and supplied with air under pressure from a hollow annular base or reservoir
cominon to all, by fixing a diaphragm across the said reservoir, so as to separate
the inlet passage from the end of the said annular base, and by slightly inclining or
sloping the several nozzles, or varying their lengths, or the size of their several
orifices progressively.
The object which I have in view is to create a powerful updraught in tho
chimney, and this is effected in the most simple and efficient manner by the
annular ejector with the continuous slit or orifice opening inwards and upwards at
or towards the top of the chimney as shown, and supplied with air under pressure
from any convenient source.
I find that a funnel or cowl affords a convenient means for supplying air under
pressure to my ejectors.
The inlet cowl C is arranged to turn and face the wind, and the air thus caught
is compressed within the tube C', and delivered in a stream at considerable velocity
through the circular orifice a of the ejector A. D is a valve or damper by which
the pressure of air can be regulated.
The chimney pot B is formed with a collar moulding forming the ejector as
shown, and this collar is provided with a nozzle or supply tube, which may be
connected by means of a pipe to any suitable apparatus for delivering air under
pressure to the ejector.
Referring now to Figs. 3 and 4, the same arrangement of parts will be observed,.
but in these Figures I have shown, by way of example, how to adapt the Invention
to existing chimney pots.
In such cases I fit thereto a separate chimney top, preferably made of ziuc, and
containing an air cjector A similar to that hercinabove described...
3
1
...

page_text: In Fig. 3, the air inlet cowl C is shown as adapted to rotate while the ejector
remains fixed, whereas in Fig. 4 the ejector is fitted so as to rotate along with the
air inlet funnel or cowl C, the edge of the rotating part of the chimney top working
in a trough of sand, which is protected from rain by a flange in the manner usually.
practised and well known.
By this arrangement, the air enters direct from the air inlet funnel or cowl C
into the annular ejector, instead of passing downwards and upwards through a
length of pipe.
In Figs. 5, 6 and 7, I have shown my Invention applied to the ventilation of
Bowers, the air ejector A being fitted near the top of a ventilating shaft, the
updraught in which is further accolerated by the heat from a furnace D¹ within
and towards the base of the said shaft.
E represents the sewer and B the ventilating shaft corresponding to the chimneys
shown in the previous Drawings.
The stove D' is preferably a closed one, its products of combustion being carried
off by a separate flue d.
The stove D is so arranged that when in working order, it exposes a large
extent of highly heated or red hot surface to the ascending sewer gases, thereby
destroying any living organisms contained therein.
The air ejector A is connected by a pipe or pipes with a fan, blower, or air pump
driven by any suitable means, and thus air under considerable pressure is forced
out of the orifice of the annular ejector, inducing, as before explained, a steady and
powerful updraught in the shaft B.
In this case also I might use an ejector composed of several separate nozzlos
arranged in a circle and supplied with air from a hollow annular baso or tube
common to all of the said nozzles, but for the reasons above stated, I prefer the
ejector having a single continuous orifice or slit.
It will be understood that it certain cases I may use a shaft fitted, as above
explained, with an ejoctor or ejectors for the ventilation of mines, sewers, and such
like underground workings, apart from a furnace such as D' arranged with the
said shaft, and also that a series of rooms may be ventilated by a cominon shaft or
shafts, by suitably connecting the several rooms with such shaft, and inducing
therein a powerful updraught by one or more ejectors constructed and arranged
according to my Invention."
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed, I declare that what
I claim is:-
1. The adaptation to chimneys and ventilating shafts, of air ojectors constructed
and arranged in the manner and for the purpose hereinabove described with
reference to the Drawings.
2. The combination with a ventilating shaft or chimney and a fan, air pump,
or equivalent apparatus for delivering air under pressure, of an air ejector such
as A having a hollow or tubular body or base connected with such air delivery
apparatus, and a continuous discharge orifice or slit, or a series of separate discharge
nozzles facing inwards and upwards, substantially as described, for the purpose of
creating a powerful updraught within the said shaft or chimney as set forth.
3. A chimney pot having an air ejector moulded therein, or forming part thereof,
the said ejector being connected with an inlet funnel or cowl, or with an air pump
or its equivalent, for delivering thereto air under pressure substantially as described
with reference to Figs. 1 and 2 and for the purpose sot forth.
4. The adaptation to existing chimney pots of air ejectors supplied with air
under pressure by means of inlet funnels or cowls, or by an air pump, fan, or
equivalent apparatus, in the manner and for the purpose described with reference
to Fig. 3 of the Drawings.
5. Tho ventilating ejector chimney top described with reference to Fig. 4.

page_text: 6. The combination with a sewer or tunnel, of the ventilating shaft B, air
ejector A, and means substantially as described for supplying air under pressure
to the said ejector, as and for the purpose described with reference to Fig. 5 of the
Drawing.
7. The combination with a sower or tunnel, of the ventilating shaft B, air
ojector A, furnace D, and means substantially as described for supplying air under
pressure to the said ejector, whereby provision is made for inducing a powerful
updraught within the said shaft, and for subjecting the sewer gases and foul air,
as they are carried off, to the purifying action of heat, substantially as described
with reference to Figs. 5, 6 and 7 of the Drawings.