CERTAIN NEW AND USEFUL IMPROVEMENTS IN STEAM JETS
Year: 1866

page_text: LETTERS PATENT to George Tomlinson Bousfield, of Loughborough Park,
Brixton, in the County of Surrey, for the Invention of "CERTAIN NEW
AND USEFUL IMPROVEMENTS IN STEAM JETS."-A communication from
abroad by David Meeker Nichols, residing at the City of New York,
United States of America.
Sealed the 11th December, 1866, and dated the 17th September 1866.
COMPLETE SPECIFICATION filed by the said George Tomlinson Bousfield
at the Office of the Commissioners of Patents, with his Petition and
Declaration, on the 17th September 1866, pursuant to the 9th Section
of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, BE IT
KNOWN that I, GEORGE TOMLINSON BOUSFIELD, of Loughborough Park,
Brixton, in the County of Surrey, do hereby declare the nature of the said
Invention for CERTAIN NEW AND USEFUL IMPROVEMENTS IN STEAM JETS," (a com-
munication to me from abroad by David Meeker Nichols, a person resident
at the City of New York, United States of America,) and in what manner
the same is to be performed, to be particularly described and ascertained
in and by the following statement thereof, that is to say :-
The Invention which constitutes the subject-matter of this Patent has
reference to the steam jet used for accelerating the current of air in the flues
of steam boilers and for other purposes. Such jets have heretofor been
composed either of a single nozzle or of a series of nozzles arranged parallel

page_text: to each other in the flue, and all pointing in the same direction, but their
operation has not been as efficient as the quantity of steam expended would
lead one to believe it should be. As it is always desirable that the natural
draught of a flue or chimney should be available for the purpose of lighting
the fire and of maintaining it when great activity of combustion is not
required it has been customary to arrange the nozzles of such jets in the
ordinary flue or chimney used to excite the combustion of the fuel for a
steam boiler by natural draught, and as the current of air moving in such a
flue by mere draught is necessarily slow, the area of such a chimney or funnel
is made proportionately large; on the other hand the current of air impelled
forward by a steam jet is necessarily rapid, hence the area of the flue in
which it moves should be materially smaller than that used for natural draught,.
and consequently if the steam jet be applied (as has heretofore been the case)
to the latter either a much larger number of nozzles and a much larger
amount of steam must be used than is necessary for draught alone, so as to
keep the entire mass of air in the flue moving in one direction, or if a less
number of nozzles be used than is required for this purpose they must be set
so far apart that reverse currents or eddys will form between the direct
currents in the vicinity of the jets of steam, and a portion of the steam will be
expended in keeping such. eddys in motion and uselessly as respects the
excitement of the draught of air through the fuel.
Again, the form of the orifices of the steam nozzles hitherto used in steam
jets has generally been circular, consequently the transverse sections of the
jets issuing from them are circular, and when such jets meet by expansion
they do not fill the area of the flue in which they operate at the place of first
meeting just as a series of circles although touching at four parts of their
circumference have spaces between their curved sides (see Diagram, Figure 3);
hence the air in the flue is not acted upon equally by the jets of steam,
and this defect prevents the operation of the jets being as effective as it
should be.
The Invention which constitutes the subject of the present Patent is
designed to obviate the loss of useful effect due to the arrangement of a
steam jet in a flue of suitable size for natural draught, and at the same time
to enable such a flue to be retained so that the natural draught may be used
in starting the fire or at other times as found convenient, and yet the steam
jet can be used when required with the best effect; it is also designed to
obviate the loss of useful effect due to the round form of the jets of steam.
To these ends the first part of the Invention consists of the combination of a
series of steam nozzles with a flue divided into two divisions (one of the

page_text: proper area from the rapid current of air produced by the steam jet and the
other of larger area,) and with a valve or valves, by means of which the
larger division may be closed or opened, hence the entire area of the larger
flue may be used (by opening the valve) for the natural draught, or by
closing the valve the area in the vicinity of the steam jet may be reduced
to the proper dimensions to enable the jets of steam to operate to the
best effect upon the air by being set so close together that their effect is
concentrated npon the air in the flue, and that the formation of eddys between
the direct currents is prevented.
The second part of the Invention consists of a steam jet composed of a
series of nozzles having orifices of square or other equivalent form, so that
the jets of steam delivered by them when meeting will leave no spaces between
them, or, in other words, having orifices of such form that their transverse
sections when placed side by side will cover up a plane surface. The form
that has been employed with success for this purpose is the square, but it is
evident that a triangular or hexagonal form (if the nozzles be properly
arranged) will operate substantially in the same manner, because a plane
surface may be completely covered with equal triangles or hexagons in the
same manner as it may be with squares.
The accompanying Drawing represents a steam jet constructed in accordance
with both parts of the Invention.
Figure 1 represents a transverse vertical section of this apparatus, the line
x, x, Figure 2, indicating the plane of section; Figure 2 is a plan or top
view of the same; Figure 3 is a diagram representing the effect of the jet
as compared with the ordinary jets of round nozzles.
Similar letters of reference indicate like parts. In this example a flue A is
used of sufficient size to be employed in lighting the fire with the natural
draught, and this flue is divided into two divisions by the small pipe B secured
centrally within it. The area of this small pipe is of the proper size for the
passage of the current of the gaseous products of combustion when impelled
at the requisite speed by the jets of steam. The series of nozzles C composing
the steam jet are arranged (as seen in the Drawing), so to act upon the
current of gaseous products passing through the small pipe which forms the
smaller division of the flue. The flue is fitted with two flap valves D, which
may be opened or closed; when they are opened the whole area of the flue
(with the exception of that occupied by the steam jet) is available for natural
draught; when they are closed the area of only the smaller division is left free,
consequently the action of the jets of steam issuing from the nozzles may be
concentrated upon the gaseous products with the best effect; the nozzles may

page_text: be set so close together that there is no space for the formation of reverse
currents between the jets and the number of nozzles employed, and con
sequently the quantity of steam expended may be reduced to the lowest
practical limit, although the same apparatus has within it the capacity
(when the steam is shut off and the valves opened) to work with as good
effect as old apparatuses by the natural draught.
In order that the apparatus thus described may embody the second part of
the Invention the nozzles of the steam jet are formed in the present example
with 1 square orifices, so that the jets issuing from them when expanded touch
simultaneously at all sides (as indicated in Diagram 3) instead of leaving
spaces as circular jets do. It is believed that the best effect will be obtained
by combining both parts of the Invention in the same apparatus as is
represented in the Drawings, but the first part may be used without the
second and the second without the first if deemed expedient. In the former case
nozzles of the customary form would be used with the divided flue and valves;
in the latter the improved nozzles would be used without the divided flue and
valves. It has been found by experiment that the effect appears to be
greatest when each nozzle is from one-fourteenth to one-twelfth of an inch
square, and when they are arranged so that their centres are from one and
one-eighth inches to one and three-eighths inches apart, but these measure-
ments may of course be varied as found expedient. The orifices of the nozzles
may be placed from an inch to one and one-balf inches below the entrance to
the division or pipe into which they discharge, and the upper end of this pipe
should be flaring to produce the best effect. In place of using a single pipe
to supply the nozzles with steam, as represented at Figures 1 and 2, a
separate supply pipe may be used for each row of nozzles, and when three or
more rows of nozzles are used the supply pipes may be arranged as repre-
sented in Figures 4 and 5, so as to obstruct the flue to a less extent. In this
case the several supply pipes may communicate with one header (E, Figure 4,)
or distributing chest, which may be placed outside of the flue or funnel. The
valve or valves used may be hinged at one side instead of at their centres if
preferred, and in case a double funnel be used (as herein-after described), or
in case the smaller division of the flue be placed at the side of the larger, but
one valve is required.
Steam has thus far been described as the impelling fluid to be used in the
nozzles, but it is obvious that air or any gaseous material under pressure may
be substituted for steam.
In place of forming the divided flue in the manner thus far described the
small pipe which forms the smaller division may be placed outside of the

page_text: larger pipe, and may be provided with a separate funnel to discharge through,
the valve or valves being applied as before to the larger division or funnel;
in this case two funnels or flues will be used, the smaller for the steam jet and
the larger for the natural draught.
What is claimed as the Invention to be secured by Letters Patent is,―
The combination of a series of nozzles with a divided or duplex flue and a
valve for one division thereof, all operating substantially as set forth.
Also, the steam jet consisting of a series of nozzles of such form that
their combined transverse sections fill up a plane surface, substantially as set
forth.
In witness whereof, I, the said George Tomlinson Bousfield, have here-
unto set my hand and seal, this Tenth day of September, in the year
of our Lord One thousand eight hundred and sixty-six.
GEO. T. BOUSFIELD. (L.S.)