US2578934A

US2578934A - Adjustable burner for liquid fuel

Info

Publication number: US2578934A
Application number: US753214A
Authority: US
Inventors: Hendrik J J Janssen
Original assignee: Individual
Current assignee: Individual
Priority date: 1945-08-01
Filing date: 1947-06-07
Publication date: 1951-12-18
Anticipated expiration: 1968-12-18

Description

% SHEETS--SHEET 1 Filed June 7, 1947 invznfor:

H drik J.J. Jan- Dec. 18, 1951 H. J. J. JANSSEN ADJUSTABLE BURNER FOR LIQUID FUEL 2 SHEETS--SHEET 2 Filed June '7, 1947 invenfon H ndr'lk J.J.Jansszr 5g MZiMTEH His AHorncg Patented Dec. 18, 1951 UNITED STATES PATENT @FFICE Application June 7, 1947, Serial No. 753,214 In the Netherlands August 1, 1945 Section 1, Public Law 690, August 8, 1946 Patent expires August ll, 1965 12 Claims. (C1. 299-58) This invention relates to adjustable burners for liquid fuel of the type having a swirl chamber connected to a return line such for example as is described in British specification No. 220,954.

Hitherto the output in such burners has been regulated chiefly by varying the flow in the return line, the pressure in the return line from the swirl chamber being consequently varied. With this arrangement the pressure in the return line is always lower than the pressure produced in the system by the fuel pump.

In general the range of output which can be obtained with such burners is too small for marine use. It is an object of this invention to provide a greater range of output for such burners. This is of especial advantage for use in ships when the latter are maneuvering, since with a greater range of output it is no longer necessary to extinguish burner when the consumption of steam is temporarily reduced. When burners are extinguished they have to be withdrawn from the furnace, since otherwise the strong radiation to which the burners are exposed will damage them when they are no longer cooled by the flow of atomized fuel. This withdrawal of the bumers is a tedious and difiicult operation.

@According to the present invention the return line will only be used as such when the burner output is to be reduced to a minimum. When the burner output is to be increased to a maximum the return line will be used as a supply line. At an intermediate output a state is reached in which the return line is closed. A suitable control system is provided for controlling the operation of the return line in accordance with the fuel pressure in the fuel supply line; this may give a continuous variation of flow in the return line as one passes from the state of maximum output to the intermediate state and thence to the state of minimum output.

In order that the invention may be well understood, reference will be made to the accompanying drawings, in which:

Fig. 1 shows a diagrammatic elevation partly in section of a burner installation according to the invention,

Fig. 2 shows a detail sectional elevation of the control valve of the installation shown in Figure 1,

Fig. 3 is a similar view to Figure 2 showing the control valve in an alternative position,

Figs. 4, 5 and 6 show a transverse cross-section through an alternative form of control valve, the three figures showing the control valve in different positions,

Fig. '7 shows a vertical cross-section through the head of a burner according to the invention,

Fig. 8 shows a cross-section on the line 8-t of Figure 7,

Fig. 9 is a plan view of the distributor plate of the burner head shown in Figure '2,

Fig. 10 is a view of the same plate taken from below,

Fig. 11 shows a vertical cross-section through the head of another form of burner according to the invention.

Fig. 12 shows a cross-section on the line l2-l2 of Figure 11,

Fig. 13 is a plan view of the distributor plate of the burner head shown in Figure 11, and

Fig. 14 is a view of the same plate taken from below.

Referring now to Figure 1 of the drawings, fuel is withdrawn from a container II by a pump t and forced under pressure through the pressure line t to a burner 5. A branch 6 leads from the line t to the control valve 7, the piston 8 of which is shown in Figure 1 in the position in whichline 6 is closed and in which connection is made between a return line 9 and a line Ila, which returns fuel to the container i. In this position of the control valve the pump forces fuel under pressure to the burner through line t only. A Y-piece ill receives the fuel from line H and leads the same through the line H to the swirl chamber of the burner 5 from which the fuel is sprayed into the furnace. The Y-piece It further connects an inner line i2 leading from the swirl chamber to the line 9 and in this way return of fuel from the swirl chamber to the container i i eiiected.

In Figure 2 the control valve is shown in the position in which both lines 6 and I la are closed. In this case the fuel is supplied to the burner through line 6 and there is no return.

In Figure 3 the control valve is shown in the position in which line i la is closed and in which line 6 is connected to the burner through line 9. In this position the pump supplies fuel under pressure to the burner not only through line t but also through lines 6 and 9.

In the position shown in Figure l, the line l2 acts as a return line. In the position shown in Figure 2 the line It is cut off. In the position shown in Figure 3 line I2 serves a; a feed line.

In Figures 4, 5 and 6 there is shown a rotary valve which may replace the piston valve 8. This rotary valve has a plug l8 rotatable in a housing ll. Openings 6, 9 and ii a in the housing ii are connected respectively to the lines 6, 9 and lie.

The positions of the rotary valve shown in Figures 4, and 6 correspond respectively to the positions of the piston valve shown in Figures 1, 2 and 3. By suitable dimensioning of the feed and return openings it is possible continuously to vary the flow of fluid from one position to another by rotation of the plug l8. The plug is suitable for hand control. If the pressure of the pump is regulated by means of a control valve in accordance with the pressure of the boiler, the plug may be set manually to the three main positions illustrated in Figs. 4, 5 and 6, and the boiler pressure will then be maintained automatically within the range of control corresponding to these positions. In this way partly automatic firing is effected.

In the arrangement shown in Figures 1 to 3, the position of the control valve is controlled by the pump pressure. A spring l3 adjustable by means of a screw ll tends to move the piston 8 to the left as seen in Figure l, and the pressure exerted by the pump tends to move the piston to the right against the action of the pressure of the spring I3. In this way the piston 8 takes up a different position for each different pressure exconnected to the valve I through a needle valve l5 which serves to retard the flow of fuel and thus to slow down the movement of the piston 8 to the right, whilst a one-way return valve is provided between the valve 1 and the line 4 to allow a rapid flow of fuel when the piston moves in the reverse direction.

If the pump pressure is controlled by a regulating valve controlled in accordance with the boiler pressure, then fully automatic firing control can be obtained, always provided that the flow of combustion air 15 simultaneously controlled in accordance with the pump pressure, which pressure in its turn is controlled in accordance with the boiler pressure.

Referring now to Figures 7-10, the burner therein illustrated is provided with concentric pipes II and [2 serving respectively for the feed and return of fuel to the burner tips. An annular space 3 between the two pipes serves for feeding fuel. A central space 4 inside the pipe l2 may serve either for feed or for return of fuel. Fuel passes through the annular space 3' to a circumferential groove 5', which is cut concentrically in a distributor hear I 5a, from which the fuel passes through openings 6' in a distributor plate 1' and thence through holes 8' and tangential slots 9' into a swirl chamber Ill. The swirl chamber I0 is provided with two central openings, namely a spray opening II and a return opening l2. The swirl chamber [0' is enclosed between the distributor plate 1 and a spray plate l3. A centering ring l4 ensures that when these two plates arefitted into the distributor head l5a' the plates are held concen- 21208113! and retained by means of a union nut When the central space 4 serves to supply fuel to the burner tip, the fuel passes through holes 16', I7 and tangential slots l8 into the swirl chamber Hi. When therefore the spaces 3' and l are both used for feeding fuel, the fuel will reach the swirl chamber via six tangential slots, namely the three slots 9' and the three slots I 8' and also through the central opening l2. Fuel leaves the swirl chamber in the form of a spray through the spray opening H. In this case therefore fuel enters the swirl chamber in seven streams and the burner is operating within the range of maximum output.

When the return line is closed and no fuel passes therethrough, fuel passes to the burner tip through the annular space 3 alone and reaches the swirl chamber through the three tangential slots 9. In this case the output of fuel spray is naturally less than in the abovementioned case.

When the return line is connected to the atmosphere, or to the suction side of the pump, the spray output will be still less, since a part of the fuel entering the swirl chamber is now returned via the opening I2 and the space, 4' to the reservoir or to the pump.

When the pump is operating within the range of maximum output, and seven streams of fuel flow into the swirl chamber, six of these streams enter tangentially and produce a swirling motion in the chamber. The seventh stream enters by the central openin l2 and has no swirl action. Since all seven streams mix, the seventh stream hinders the swirl action.

In Figures 11 to 14 a burner tip is shown in which three streams enter the swirl chamber tangentially and a fourth stream enters the chamber centrally, this latter stream having a rotary'motion about its own axis because of its passage through a swirl chamber 23 through which it passes before entering the swirl chamber 25. It should be mentioned that the use of two swirl chambers of different sizes has already been proposed, for example in Le Chauffage par les Combustibles Liquides," by A. Guillermie, 1935. In the present case, however, the two swirl chambers are connected by a central opening 24 which may be approximately equal to or smaller than the spray opening of the main swirl chamber 25.

The dimensions of the tangential slots and of the spray opening may be so selected that the feed from the space 3' produces only a hollow jet from the spray opening. The feed from the space 4' is then able to fill the hollow in the jet.

The feed through the space 4' may be at approximately the same rate as the feed through the space 3', whilst when fuel is returned through the space 4' the rate of return may be approximately half the rate of feed through the space 3'. In this way the spray output at constant pump pressure may be varied within a range of from 1 to 4. When the pump pressure is varied within a range of from 1 to 4, so as to double the rate of feed, the spray output may be varied within a range of from 1 to 8.

In Figure 11 the distributor plate is indicated by reference numeral l9 and the distributor head by reference numeral 20a. A union nut 20b is employed for retaining the plates. The distributor head differs from that shown in Figure '7, and the distributor plate also differs from the plate 1' shown in Figures 9 a 'i 10.

The distributor plate shown in Figures 11 to 14 has a circumferential groove 2| connected by means of tangential slots 22 with a swirl chamber 23, which is connected in turn through a central opening 24 to the main swirl chamber 25. The distributor head is provided with a circle of auraeu holes 26 for feeding fuel to the groove 2| in the distributor plate It. The operation of this arrangement is as follows:

When the burner is to have a maximum output, fuel is fed both through the space 3' and also through the space 4' to the burner tip. Fuel passes from the space 3' through three tangential slots into theswirl chamber 25. Fuel from the space 4' passes through the circle of holes 26 into the groove 2| and thence through four tangential slots 22 into the swirl chamber 23 and from thence passes through the central opening 24 into the swirl chamber 25. In this case the fuel enters the swirl chamber in four streams all of which contribute to the swirl action.

When the space 4' is closed only three streams enter the swirl chamber 25, and when communication is established between the space 4 and the reservoir a part of the fuel fed to the swirl chamber 25 .is not sprayed but passes back through the return line. It is desirable to make the return openin and the spray opening in the swirl chamber 25 of the same size, since this eliminates the effect of the viscosity of the fuel on the axial distribution in the swirl chamber.

In the case of the burner illustrated in Figure 7, it is not advisable to make the central return and feed opening larger than the spray opening, as this would lead to the swirl action being too greatly hindered when the burner is operating at maximum output.

When the three-way valve ll illustrated in Figures 4 to 6 is employed, a regulating valve, for example a needle valve may be placed behind the three-way valve in line 9. Control may then be exercised by setting the three-way valve in one of the positions shown in Figures 4 to 6 and adjusting the flow by means of the needle valve.

It is possible, however, to operate the installation without the use of such a needle valve and to exercise control by varying the pump pressure which may if desired be controlled automatically in accordance with the boiler pressure.

I claim:

1. In an atomizer, a swirl chamber; first and second entry passages to said swirl chamber, at least the first passageway being directed tangentially thereto; dual means for supplying, respectively to the two entry passageways, fuel under pressure to be atomized by fiow through said swirl chamber; regulatable means having first and second positions for converting the supply means for the second passageway into 'means for withdrawing from said swirl chamber a portion of the fuel supplied by the other of said supply means when in the second position and leaving said supply means unconverted when in the first position; and means responsive to said pressure for operating said regulatable means to move the regulatable means to the said first position at a relatively higher pressure and to the said second position at a relatively lower pressure.

2. The atomizer according to claim 1 wherein the regulatable means has an intermediate position at which said supply means for the second passageway is closed, and the said pressure responsive means is arranged to move the regulatable means to the intermediate position at a relatively intermediate pressure.

3. In an atomizer, a swirl chamber; first and second entry passages to said swirl chamber, at

least the first passageway being directed tangentially thereto; dual means for supplying, respectively to the two entry passageways. fuel under pressure to be atomized by flow through said swirl chamber; control means having a movable element movable progressively between first and second positions for converting the supply means for the second passageway into means for withdrawing from said swirl chamber a controllable portion of the fuel supplied by the other of said supply means, said control means being adapted to withdraw a progressively larger portion of said fuel as said movable element is moved progressively from the first to the second position thereof, and to leave said supply means uncoverted when the movable element is in the first position; and means responsive to the said pressure for moving said movable element progressively to said first position at progressively higher pressure and progressively to said second position at progressively lower pressures.

4. The atomizer according to claim 3 wherein the control means is arranged to close the said supply means for the second passageway when the movable element is at an intermediate position.

'5. In an atomizer, a swirl chamber having a forward orifice; two sets of entry passageways directed tangentially to said swirl chamber; dual means for supplying, respectively, to the sets of entry passageways, fuel under pressure to be atomized by flow through said swirl chamber; regulatable means connected to one of said supply means for converting the respective supply means into means for withdrawing from said swirl chamber a controllable portion of the fuel supplied through the other of said supply means; and means responsive to said pressure for operating said regulatable means to withdraw a progressively larger proportion of fuel as the pressure is decreased.

6. The atomizer according to claim 5 wherein the swirl chamber has a rear wall and a central owning through said rear wall, and the said supply means to which the regulatable means is connecwd is in communication with the said central opening, the central opening having a diameter not larger than that of the discharge orifice.

7. In an atomizer, a first swirl chamber having a rear wall and a forward discharge orifice; a first set of entry passageways disposed tangentially thereto; a second swirl chamber in rear of said first swirl chamber; a central opening in said rear wall of the first swirl chamber communicating with the front of said second swirl chamber having a diameter smaller than that of the discharge orifice; a second set of tangential swirl openings disposed tangentially to the second swirl chamber; dual means supplying, respectively to the two sets of entry passageways, fuel under pressure to be atomized by flow through said swirl chambers; regulatable means for converting the supply means for the second set of tangential entry passages into means for withdrawing from said first swirl chamber through said central opening and second swirl chamber, a portion of the fuel supplied through the other supply means through the first set of entry passageways; and means responsive to said pressure for operating said regulatable means to withdraw a portion of the fuel when said pressure is decreased.

8. In a burner installation for liquid fuel, a burner provided with an atomizer having a swirl chamber and a plurality of entry passageways; first conduit means for connecting a source of fuel under pressure to entry passageways to said swirl chamber; a three-way valve having three ports and adapted to connect the first port thereof selectively to the second or to the third port thereof; second conduit means connecting one or more entry passageways of said swirl chamber to said first port of the valve; third conduit means for supplying fuel to said second port of the valve; 9. fuel discharge conduit connected to the third port of the valve for discharging fuel to a receiver; and means responsive to the pressure of said source of fuel for actuating said valve to connect the first port thereof to the second port at a relatively higher pressure and to connect the first port thereof to the third port at a relatively lower pressure.

9. The burner installation according to claim 8 wherein the third conduit means is connected to the first conduit means and forms a branch thereof.

10. The burner installation according to claim 8 wherein the three-way valve comprises: a hollow cylinder with three axially displaced ports constituting the said three ports of the valve; a piston valve reciprocably mounted within said cylinder and having parts thereof shaped to cover the third port and place the second port in comcomprises a pressure chamber; a movable, pressure responsive element having an area thereof exposed to the pressure of fuel in said chamber; a restricted conduit connected to said source of fuel under pressure and to said pressure chamber for admitting fuel into said pressure chamber at a restricted rate; a larger conduit connected to said pressure chamber and to said source of fuel under pressure for discharging fuel from said pressure chamber; and a non-return valve opening toward the source of fuel under pressure.

12. In combination with the burner installation according to claim 11, an adjustable throttle valve in said restricted conduit for regulating the fiow of fuel.

HENDRIK J. J. JANSSEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 994,940 hemp June 13, 1911 1,022,032 Lemp Apr. 2, 1912 1,661,450 Van Sant Mar. 6, 1928 2,127,172 Hermitte Aug. 16, 1938 2,223,055 Bergey Nov. 26, 1940 2,263,913 Bargeboer Nov. 25, 1941 2,286,581 Scott June 16, 1942 2,313,298 Martin et al Mar. 9, 1943 2,374,041 Saha Apr. 17, 1945 2,379,161 Kraps June 26, 1945 2,409,504 Logan Oct. 15, 1946 2,425,589 Aubert Aug. 12, 1947