Improvements in Apparatus (Operating by Means of a Steam Jet and an Induced Current of Air) for the Prevention and Consumption of Smoke and the more Complete Combustion of Fuel in Steam Boiler and other Furnaces.
Year: 1889

page_text: Date of Application, 4th Feb., 1889
Specification Accepted, 9th Mar., 1889
Improvements in Apparatus (Operating by Means of a Steam Jet and
an Induced Current of Air) for the Prevention and Consumption
of Smoke and the more Complete Combustion of Fuel in Steam
Boiler and other Furnaces.
We, ALFRED DON of Donville Villa, Garner's Avenue, Marrickville, Sydney, in
the Colony of New South Wales, Australia, Engineer, and JOHN SANDS, of
Harris Street, "Pyrmont, Sydney aforesaid, 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 :-
Our invention consists of improvements in apparatus (operating by means
of a steam jet and an induced current of air) for the prevention and con-
sumption of smoke and the more complete combustion of fuel in steam boiler
and other furnaces; the same being an improvement upon apparatus shown and
described in the specification of Letters Patent No. 1083 A.D. 1888 already granted
to the undersigned Alfred Don.
The apparatus shown and described in the specification of the former invention of
the said Alfred Don comprises in one form a vertical air induction pipe, shaped,
(or bent or curved at the lower end), constructed preferably of cast iron; oval, or of
other preferred contour in cross section and of particular dimensions of area, fixod
in front of the furnace with its curved portion projecting into the furnace through
an opening above or in the top of the door thereof; its exit being bell shaped ; so
constructed that lines drawn therefrom will reach all the sides or angles of the firebox
opposite thereto just above the level of the fuel, and the said exit having a slightly
downward deflection over the fuel; the mouth of the said induction pipe being also
bell shaped and provided with a lid or cover for the admission or exclusion of air;
having fitted therein a vertical L shaped steam pipe, constructed preferably of
copper, carried within the air pipe so that its point of discharge is just beyond
the bend or curve of the air pipe, the said steam pipe being connected at the
other end with the steam chest or other source of supply and controlled by a
suitable valve.
There are other forms or variations of the apparatus the subject of the said former
invention as set forth in the specification thereof, but it is therein stated that the said
invention is most efficiently and conveniently carried out by the use of an air pipe
bent or curved at the lower end thereof.

page_text: Having reference to the said former invention our present improvement has for
its object :-
(1) A corresponding result with the consumption of a smaller quantity of team.
(2) The absence of a considerable noise which is found to accompany the working
of the previous form of apparatus.
(3) An increased efficiency consisting in a greater margin of power under control
whereby a very much increased volume of air" may be driven into a furnace and ni a
greater velocity at will.
In carrying out our invention we construct a pipe bent or curved at its lower
end, (or of an L shaped form), similar to the air induction pipe described in the
specification of the former invention, but differing somewhat therefrom as herein-
after mentioned, with a bell shaped distributing exit having a downward deflection
constructed and projecting into the furnace or firebox in the manner described in the
specification of the former invention. The construction of the said pipe and other-
wise of the apparatus the subject of the present invention differs from the former
apparatus in the following material respects :-
:-
1. That the area and dimensions of the said pipe are immaterial within approxi-
mate limits, so long as the lower portion thereof is of such convenient size as to
admit of the construction of the distributing exit in the requisite manner.
2. In the apparatus the subject of the present invention we use an annular injector
(into which the steam pipe is carried) which is fixed in the mouth of the before
mentioned pipe, a current of air being induced through the centre of the annular injertor
by means of the stem. This annular injector is fitted with a regulating screw by
means of which the admission of steam, and the velocity of the air current occasionel
thereby, may be increased or diminished.
The principle underlying the former invention, and which finds a more efficient
operation in our improved form of apparatus, is that a large volume of air is driven
into the turnare at a great velocity or pressure, being, it is believed, a very much
larger volume of air, and driven at a greater velocity or pressure, than has been
attempted in or effected by other smoke preventing apparatu, and that the same
heing distributes by the means adopted all over the surace of the fuel the whole of
the carbon and gases generated are forced by pressure into immediate chemical
union with the requisite amount of oxygen for their complete combustion.
We may state that the use of the steam jet in connection with our invention
is for the purpose only of inducing the air current, and not for the introduction
of combined air and steam as in the case of some other smoke preventing
apparatus.
In the use of the former apparatus a current of air is induced which attains a
velocity or pressure through the inlet equal to supporting from one eighth (4th)
of an inch to one fourth (th) of an inch of a column of mercury, but not
approximately exceeding the latter velocity. By the use of an annular injector we
introduce a current of air into the furnace at a greatly increased velocity, but
approximately the like quantity of air to produce the desired result. By means of
the said annular injector a current of air could be projected into the furnace at a
velocity equal to supporting from one fourth (th) of an inch to seven (7) inches of a
column of mercury, and we have found in practice that the use thereof so as to give
approximately a velocity equal to supporting one a half inches of a column of mercury
produces the desired result.
In the apparatus the subject of the said former invention the air induction pipe
thereof is constructal for the size of furnace therein mentioned with a diameter of
four (4) inches by two and a half (2) inches, and in using the said apparatus for
attaining the full result the lid or valve at the mouth of the pipe is fully opened and
allows the admission into the furnace within a given time of the quantity of air
which a pipe of such dimensions can contain at one and the same time passing into
the furnace at a velocity or pressure as hefore stated equal approximately to supporting
a quarter () of an inch of a column of unreury. We construct the said annular
injector for a furnace of approximately the same size with an apperture for the

page_text: admission of air of a diameter of one and one eighth (11th) inches only, or approxi-
mately an area one seventh (th) of the former apparatus, whilst, as before stated,
the velocity or pressure of the air current is increased from the capacity of
supporting one fourth (th) of an inch to being equal to supporting one and a half
(14) inches of a column of inercury.
The said invention differs in operation from the former invention in the following
particular, that in the use of the annular injector the velocity of the current of air is
so much greater that the distribution thereof is aided by the same being in the first
instance projected against some portion of the pipe entering the furnace. In the
specification of the former invention the said pipe is termed an air induction pipe :
In our improved apparatus the said annular injector is the air induction pipe and
the pipe entering the furnace with its distributing exit serves mainly the purpose of
a distributing medium, and is henceforth referred to as the distribution pipe. "When
the annular injector is used in combination with an L shaped distribution pipe, or a
pipe bent or curved at its lower end, which we regard as the preferable or most con-
venient form of apparatus, the current of air is projected against the bent portion
of the pipe. If the annular injector were used in combination with a straight pipe
the same result could be brought about by inserting the annular injector obliquely
therein.
Having regard to this feature of the invention, we do not restrict the same merely
to the combination of an annular injector with a distribution pipo entering the
furnace, as other means or combinations can be arranged whereby a current of air
may be projected into a furnace by means of an annular injector such as that used by
us with the use of some other means of distributing the air current at the time of
entering the furnace.
One important result from the use of the said annular injector is the consumption
of a very much smaller quantity of steam for the use of the apparatus.
Another important result is the absence of a considerable noise which is found to
accompany the working of the former apparatus, the working of our improved
apparatus being practically noiseless.
A further result is the margin of power under control to permit of air being
introduced into the furnace at a greater velocity and in greater volume than is
practicable by means of the former apparatus, the velocity of the air current, and the
volume of air, laving sometimes to be increased having regard to the quality or an
extra quantity of the fuel.
The said improved apparatus is illustrated in the accompanying drawings, in
which
Figure 1 (sheet 1) represents a vertical longitudinal section of an ordinary marine
boiler and furnace, the dimensions of the latter being six (6) feet by two (2) feet
nine (9) inches with the complete apparatus as used by us affixed thereto.
Figure 2 (sheet 2) is a sectional elevation of the distribution pipe with the annular
injector fitted therein.
Figure 3 (sheet 2) is an exterior elevation of the same parts.
Like letters indicate the same parts throughout the various views.
In Figure 1 of the said drawings G represents the boiler; H the furnace; I the
furnace door; and F the distribution pipe with the annular injector CC fitted therein,
the same being secured to the furnace and entering the firebox as shown in the
drawing. K represents the steam pipe fixed into a side socket of the annular injector,
extending upwards to a stop cock L inserted in the steam chest M. L' represents
another steam cock placed in proximity to the annular injector.
In Figure 2 F represents the distribution pipe, and C C¹ the annular injector.
The said distribution pipe F may be of any suitable contour, but we construct the
same tapering from the top to the exit, the upper portion thereof circular in form
and running into an oval at the exit. The upper portion as far as the bend or curve
may be of any convenient length and we construct the same for a furnace of the said
dimensions with a diameter of about two (2) inches, but the same is not material
within approximate limits. We construct the lower portion of the said distribution

page_text: pipe from the bend or curve therein of such length as mɩy bo requisite for entering
the furnace, with an area for a furnace of the before mentioned dimensions of about
twelve (12) inches at the exit. The said area may be slightly exceeded or diminished
so long as it is of sufficient size to admit of the proper construction of the hell shaped
exit. We construct the said exit for a furnace of the said dimensions of an oval
form (5) inches in length by two and three quarter (24) inches in width, with such
downward deflection thereof that the currents passing through it will reach all the
sides or angles of the firebox opposite thereto approximately above the level of the
fuel. The size of the exit and shape as regards length and breadth, and the deflection
thereof, will necessarily vary with the size and shape of the furnace. The said exit
enters a furnace of the before mentioned dimensions so as to extend slightly beyond
the inner batile plate of the furnace door; but such extent may be increased or
diminished to adapt the said exit to the furnace so that the same may be fitted therein
at the requisite angle of deflection.
As stated in the specification of the former invention the steam pipe K is extended
upwards, along, and over the end of the furmen as far as possible, so as to ensure
the dryness of the steam it is intended to convey to a connection with the steam
chest as appearing in Figure 1, and is controlled at or near such connection by a
suitable steam cock or valve.
As stated in the specification of the said former invention, imme lately above the
furnace door, or centrally of its upper edge, an opening is cut suited to admit the
passage of the distribution pipe in an approsianitely tight joint through the casing of
the furnace above the door, or in the dour when the samne is closed.
The said apparatus is placed against the end of the furnace, so that its exit projects
within the firebox through the said opening.
The annular injertor as shown in Figures 2 and 3 consists of two parts; the first
part of an annular tube A. We have found the same constructed for a furnace of the
Baid dimensions with an internal diameter of one and one eighth (14th) inches to give
an efficient result. The said tube A has a handwheel 13 fitted at the end thereof for the
adjustment of the instrument. This tube is screwed at its upper end for insertion into
the second part of the instrument, being the external tube D. The lower end of the
tube A is tapered for insertion into the seating in the tube 1) below the enlargement
formed for the admission of steam from the side socket E. We have found the
instrument most effective when the tube A is carried down to, and the said seating is
fixed at, the point in the tube D. in proportion to the length thereof which is shown
in the drawing, the same being where the curve in the tube D commences. The
tube A is so constructed, and the screw is so placed thereon that when the tube A is
fixed into the tuhe 1 turns or revolutions of the handwheel B will withdraw the tubo
in the seating and regulate the annular space between the tubes occasioned thereby
for the admission of steam in the required quantity. We have found that the screw
on the tube & cut sixteen (16) threads to the inch three (3) revolutions of the hand-
wheel give a good result in general use for a furnace of the said dimensions. Tho
tube D is constructed with a diameter increased at the upper part for connection with
the steam pipe, and to give the necessary space for the admission of steam.
For larger furnaces than a furnace of the above mentioned dimensions the said
annular injector should be so constructed that the internal diameter of the tubo A will
be increased. For furnaces up to an approximate area of sixteen (16) square feet an
annular injector of the above dimensions will suffice. For furnaces of larger size the
internal area of the tube A must be increased approximately in like proportion to the
size of the furnace.
In furnaces of extra large dimensions it might be desirable to use two instruments
(as shown in Figures 2 and 3) fixed in front of the furnace in connection with tho
steam pipe K.
The apparatus is operated by setting the handwheel B so as to allow of the
admission of steam through the annular space thereby occasioned between the tubes A
and B, and then turning on the steam. It will easily be ascertained in practice how
many revolutions of the handwheel will be required to suit the quality of the fuel

page_text: supplied to the furnace. The current of air induced by the admission of steam into
the tube A at its mouth or inlet (lettered C) passing through the distribution pipe in
manner described will have the effect, with careful stoking, of almost immediately
dispersing any smoke, and of preventing smoke being generated by the fresh fuel, and
also, within a few minutes, of rendering the fuel incandescent, when the steam can be
turned off.
The steam cock regulating the supply may be manipulated during the operation so
as to be turned off gradually, the same quantity of steam not being required
throughout the whole process of combustion. After ascertaining the requisite
gradations of the supply, an automatic regulator might be affixed to the steam pipe to
regulate the control.
The said apparatus is of course available for such furnaces other than steam boiler
furnaces as are of a construction to admit of the same being adapted thereto.
The introduction into furnaces of a current of air by the aid of a steam jet has been
well known to aid in preventing or diminishing smoke and increasing the combustion
of fuel, but the apparatus heretofore employed for such purposes, and the methods of
applying the same, have not ensured the complete success with the facilities for the
operation thereof which are incident to our invention.
Our improved apparatus is simple in construction and can be applied with the
greatest facility, and at a nominal cost, to any steam boiler furnace or other furnace
to which the same may be adapted without alteration in the structure thereof. It can
also be regulated in the simplest way to ensure efficiency in operation as may be
requisite having regard to the quantity or quality of the fuel used or to other
conditions; and it works a greater economy in the consumption of fuel both directly
and indirectly in the quantity of steam required for the use of the apparatus than any
similar apparatus heretofore used.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. The combination in a smoke consuming apparatus (operating by means of a jet
of steam and an induced current of air), with a distribution pipe having a distributing
exit projecting within the fire-box of a steam boiler furnace, or other furnace to which
the same may be adapted, of an annular injector for the purposes set forth.
2. The use in a smoke consuming apparatus (operating by means of a jet of steam
and an induced current of air), of an annular injector acting in combination with a
distribution pipe or other form of apparatus so constructed as to cause the distribution
of the air current over the whole surface of the fuel for the purposes set forth.
Dated the Sixth day of December 1800.
DAILED GIG SIXTH CY 01 December 1000.
A. DON.
JOHN SANDS.
Haseltine, Lake & Co.,
45, Southampton Buildings, London,
Agents for the Applicants.