Improvements in Apparatus for Controlling the Air Supply to the Furnaces of Water Tube and other Boilers.
Year: 1896

page_text: Date of Application, 17th Feb., 1896
Complete Specification Left, 20th Oct., 1896-Accepted, 28th Nov., 1896
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Controlling the Air Supply to the
Furnaces of Water Tube and other Boilers.
I, CARL GUSTAF PATRIK DE LAVAL, of 16 Handtverkaregatan, Stockholm,
Sweden, Doctor of Philosophy and Engineer, do hereby declare the nature of this
invention to be as follows:-
The present invention has for its object to furnish certain improved means for
controlling the air-supply to the furnaces of water-tube and other boilers according to
the consumption of steam. For this object the steam generated by the boiler (or water
with a pressure following the variations of the steam-pressure) is made to act upon a
piston which is movable in a cylinder, and by suitable means is connected with the
air-controlling device. The construction of said device varies with the construction
of the water-tube or other boiler, and may consist of an air-valve communicating
with the fire-place, of a valve in the blast pipe leading to the fire-place, or any other
well known contrivance. The steam or water-pressure acting upon the piston may be
balanced by a spring-pressure, whereby the piston is put in motion in the cylinder by
the variations in the steam or water-pressure and thus enabled to perform the opening
or closing of the air-controlling device until equilibrium is restored by the spring.
Said spring is strained between two blocks, which are suspended between cross edges.
The object of these cross edges is to assure an axial attachment of the spring on the
piston and thus to enable the latter to move freely, this being obtained because the
blocks can tip sideways in all directions.
Dated this 17th day of February 1806
JENSEN & SON,
77 Chancery Lane, London, W.C., Patent Agents.
Improvements in Apparatus for Controlling the Air Supply to the
Furnaces of Water Tube and other Boilers.
I, CARL GUSTAF PATRIK DE LAVAL of 16 Handtverkaregatan, Stockholm,
Sweden, Doctor of Philosophy and 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 :-
The present invention has for its object to furnish certain improved means for
controlling the air supply to the furnaces of water tube and other boilers according to
the consumption of steam. For this object the steam generated by the boiler (or
water with a pressure following the variations of the steam pressure) is made to act
upon a piston which is moveable in a cylinder and by suitable means is connected with
the air controlling device. The construction of said device varies with the construction
of the water tube or other boiler, and may consist of an air-valve communicating
with the fireplace, of a valve in the blast pipe leading to the fire place, or any other
well known contrivance. The steam or water pressure acting upon the piston may be
Price

page_text: balanced by a spring pressure whereby the piston is put in motion in the cylinder by the
variations in the steam or water pressure and thus enabled to perform the opening or
closing of the air-controlling device until equilibrium is restored by the spring.
Said spring is strained between two blocks, which are suspended between the cross
knife edges. The object of these cross-knife edges is to assure an axial attachment of
the spring on the piston and thus to enable the latter to move freely, this being
obtained, because the blocks can tip sideways in all directions.
For making the invention more clearly intelligible an apparatus, constructed as
above indicated, is shown on the accompanying drawing, in which Fig. 1 represents a
vertical section and Fig. 2 a horizontal section on the line A.-A, Fig. 1 of the
apparatus, while Fig. 3 is a side elevation of a portion of the same.
Similar letters of reference indicate corresponding parts.
a is a piston which is movable in a cylinder b, with the lower part of which a steam
inlet supply-pipe c is connected. The piston a carries at its upper end an inverted
cup al the upper part of which is formed with a knife edge a. A similar cup fixed
in a block . is provided with a knife edge arranged at right angle to the knife
edge a². Said edges rest crosswise in corresponding pans in the piece. In the
same manner a second block k¹ carries the cup k which is provided with a knife
edge . A similar knife edge k¹ on the screw m, inserted in the top plate of the
frame of the apparatus, it is arranged at right angles to the knife edges k² just
mentioned. The two edges k² and kare resting in corresponding pans in the piece /³.
Between the blocks and a strong helical spring. is. strained, said spring being
intended to balance the steam pressure on the lower end of the piston. A pin passes
through a central hole in the screw m, piece.k, knife-edge and cup /*.and rests
with its lower end in the cup, while its upper edgeshaped end engages a corresponding
groove.h' in the under side of the lever g. The lever g rests with one end on the
edge g', fixed on the frame of the apparatus, its other end being attached to a cord f
which surrounds .a disc on the shaft of the valve-d inserted in the air supply pipe e,
leading to the fireplace of the boiler in question.
The apparatus works as follows: With normal steam pressure, equilibrium is
established between the pressure of the steam on the piston a and the spring 1, while
the valve d occupies a position in which it supplies the air necessary to the furnace for
generating a quantity of steam corresponding to the normal consumption. By
increased or diminished consumption of steam, the steam pressure at c is either
reduced or raised and the piston a moved in the cylinder b down or up until equilibrium
again is established by means of the spring 1. According to these movements of the
piston a, the valve d' is correspondingly operated by means of the parts h, g, f, thus
increasing or decreasing the air-supply through pipe e to the fireplace of the boiler.
The generation is thus also increased or decreased in a corresponding degree.
The object of the cross-edges a³ ³ and k¹ k² is to assure an axial attachment of the
spring on the piston a and thus to enable the latter to move freely, this being obtained
because the blocks i and k, owing to their being suspended between said cross-edges,
can tip sideways in all directions. Thus an oblique position of the spring does not
exert a side-pressure on the piston, which would impair its free movement on the
cylinder b.
It should be mentioned that the apparatus above described also can serve as a
pressure gauge, the lever g then being combined with a pointer that indicates the
pressure on an empirically-graduated scale.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
1. In means for controlling the air-supply to steam-boiler furnaces, the combination
of a cylinder, a piston guided in the cylinder, a steam supply-pipe leading into the
cylinder at one end of the piston, a system of blocks and knife-edges arranged between
the other end of the piston and one end of the cylinder, a spring arranged between
and bearing with one end against one of said blocks and with the other end against

page_text: another block, an air supply controlling device, and means for connecting the piston
with the air-supply controlling device, substantially as set forth.
2. In means for controlling the air-supply to steam-boiler furnaces, the combination
of a cylinder, a piston guided in the same, a steam supply-pipe leading into the cylinder
at one end of the piston, a system of blocks and knife-edges arranged between the other
end of the piston and one end of the cylinder, a spring arranged between and bearing
with one end against one of said blocks and with the other end against another block,
an air-supply controlling device, and means for connecting the piston with the
air-supply controlling device, consisting of a pin h passing through one end of the
cylinder, through one of the blocks and stepped into the other block, a lever g
connected with the pin , and a rope or cord f leading from said lever to a damper of
the furnace, substantially as set forth.
Dated this 2011 1
1000
JENSEN & SON,
77 Chancery Lane, London, W.C., Patent Agents.