LIQUID FUEL BURNER BACKGROUND OF THE INVENTION This invention relates to burners, and more specifically to a liquid fuel burner that can be used in devices such as stoves, water heaters, heaters and the like. The invention also relates to a device for supplying liquid fuel to a burner head of a liquid fuel burner. Several different types of liquid fuel burners are known. In some of these devices, capillary action causes the extraction of liquid fuel in a wick from which it burns, while in other applications air pressure is applied to a liquid fuel to move the fuel to a burner head . Although devices such as liquid fuel furnaces are often preferable to electrical devices because either the electricity is not easily accessible or the electrical devices are relatively expensive to operate, many of the known liquid fuel burners are relatively unsafe and / or They are not very efficient. It is an object of the present invention to provide an alternative liquid fuel burner that is generally safe and efficient.
It is a further object of the present invention to provide a liquid fuel burner that is relatively easy to use. COMPENDIUM OF THE INVENTION According to the present invention, a liquid fuel burner is provided comprising: a burner head; a liquid fuel tank to contain a liquid fuel; and a pump for pumping the liquid fuel from the reservoir to the burner head, the pump includes: a cylinder; a piston that can move relative to the cylinder in such a way that liquid fuel is introduced into the cylinder when the piston and cylinder are displaced in a first direction relative to each other, and the liquid fuel is pumped out of the cylinder when the piston and the cylinder is displaced to a second opposite direction with relation to each other; an inlet valve to allow the introduction of liquid fuel to the cylinder from the tank; an outlet valve to allow the liquid fuel to be pumped out of the cylinder towards the burner head; and a displaceable mass that, due to its weight, applies enough force to cause the displacement of the piston with
relation to the cylinder in the second direction, thus pumping liquid fuel out of the cylinder towards the burner head. Preferably, the inlet valve is a one-way valve to allow liquid fuel to enter the cylinder, and the outlet valve is a one-way valve to allow liquid fuel to exit the cylinder. In one embodiment of the invention, the piston can move within the cylinder to an elevated condition for introducing liquid fuel into the cylinder and to a lowered condition for pumping liquid fuel out of the cylinder. In this embodiment, the piston may be attached to a burner head through a piston tube, and the piston may define an opening to allow fluid communication between the cylinder and the piston tube. The speed of displacement of the piston relative to the cylinder, and therefore the speed at which the liquid fuel is pumped out of the cylinder, can be regulated through a control mechanism that applies a variable resistance to piston displacement relative to the cylinder. . The control mechanism may include an adjusting screw for applying a variable resistance to displacement of the piston tube.
In one embodiment of the invention, the piston tube is positioned to pass through a bushing, and the adjusting screw is threaded into the bushing in such a way that it can be engaged with the piston tube. The cylinder can be located inside the liquid fuel tank, in this case, the cylinder can communicate with the tank through the inlet valve and possibly through a filter. In one embodiment of the invention, the inlet valve and the outlet valve each include a valve closure which, in ordinary operation, can be displaced relative to a valve seat between an open position in which the closure of the valve valve is spaced apart from the valve seat to allow flow in a direction of liquid fuel through the valve, and a closed position in which the valve lock engages the valve seat to prevent liquid fuel from flowing through the valve seat; valve. In this embodiment, for each valve, the valve closure can be displaced relative to the valve seat when the liquid fuel burner is tilted in order to allow the flow of liquid fuel through the valve in a direction opposite to the flow of liquid. ordinary operation of a sense of liquid fuel. In another embodiment of the invention, the piston is fixed relative to a burner frame and the cylinder can
move relative to the burner frame. In this embodiment, the displaceable mass may be part of the cylinder or be attached to the cylinder, and the piston may include ports to allow the liquid fuel to be drawn into the cylinder or to be pumped out of the cylinder. The burner may include a frame formed of tubular sections, in which case the reservoir may be formed through at least a portion of the tubular sections. In one arrangement, the frame is curved along the side portions thereof and the burner includes a stabilizing mass for self-straightening the frame if the burner is tilted to the side. The stabilizing mass can be the displaceable mass. The burner may also include a regulator in the form of a valve for regulating the supply of liquid fuel to the burner head and consequently the intensity of combustion in the burner head. In one embodiment of the invention, the burner includes a double shut-off device to prevent the flow of liquid fuel to the burner head when the pressure in the burner head falls below a predetermined amount, for example, if the burner is turned off. flare, and to prevent a back-pressure displacement of the liquid fuel from the burner head towards the cylinder when the pressure of the burner head is
it rises above a predetermined magnitude. The invention encompasses a pump for pumping liquid fuel from a reservoir to a burner head of a liquid fuel burner, the pump includes: a cylinder; a piston that can move relative to the cylinder such that liquid fuel is introduced into the cylinder when the piston and cylinder are displaced in a first direction relative to one another, and the liquid fuel is pumped out of the cylinder when the piston and the cylinder is displaced in a second opposite direction with relation to each other; an inlet valve to allow liquid fuel to be introduced into the cylinder from the reservoir; an outlet valve to allow liquid fuel to be pumped out of the cylinder into the burner head; and a displaceable mass which, due to its weight, applies sufficient force to cause the displacement of the piston relative to the cylinder in the second direction, thereby pumping the liquid fuel out of the cylinder towards the burner head. The inlet valve and the outlet valve may each comprise a one-way valve. BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described in more detail, by way of example only, with reference to the accompanying drawings in which: Figure 1 shows a perspective view of a liquid fuel burner in accordance with an embodiment of the present invention; Figure 2 shows a partial cross-sectional view of the burner illustrated in Figure 1; Figure 3 shows a perspective view of a liquid fuel burner according to another embodiment of the invention; Figure 4 shows a cross-sectional view of the burner of Figure 3 with the frame omitted for clarity and with a burner head in a lowered condition; Figures 5 and 6 show cross-sectional views similar to the views of Figure 4 with the burner head in an elevated condition and in an inclined condition, respectively; Figure 7 illustrates a cross-sectional view of a portion of a liquid fuel burner according to another embodiment of the present invention with a burner head in a lowered condition; Figures 8 and 9 illustrate cross-section views similar to the view of Figure 7 with the burner head
in a high condition and in an inclined condition, respectively. DETAILED DESCRIPTION OF THE INVENTION Figures 1 and 2 of the accompanying drawings illustrate a liquid fuel burner in accordance with one embodiment of the present invention. In this modality, the liquid fuel burner is in the form of a paraffin heater 10 including a frame 12, a burner head 14 mounted on the frame, a reservoir 16 for containing paraffin, and a pump 18 for pumping the paraffin from the reservoir 16 towards the burner head 14. As representatively illustrated in Figures 1 and 2, the frame 12 can include four pastes 20 joined together in a base 22 of the frame. The legs 20 can be formed of tubular material, such as for example tubular steel sections in such a way that the reservoir 16 is formed inside the hollow legs 20. Removable covers 24 can be provided for access to the reservoir 16. As can be seen, the operatively upper ends of the legs 20 may be connected to a cooking vessel holder 26 to support pots, pans, and the like (not illustrated). The support 26 typically comprises an outer ring 28, an inner ring 30, and four radial members 32 that extend between the outer ring and the inner ring.
With particular reference to Figure 2, the pump 18 can include a cylinder 34 and a piston 36 that can be displaced relative to one another. In this embodiment of the invention, the piston 36 is fixed on the frame 12 and the cylinder 34 is fixed on the frame 12 and the cylinder 34 can be moved relative to the frame in the directions of the arrows A and B in Figure 2. The piston 36 is seen as including a first port 38 and an inlet valve 40 to allow the paraffin in the reservoir 16 to be brought to the cylinder 34, and a second port 42 and an outlet valve 44 to allow the paraffin is pumped out of the cylinder 34 towards the burner head 14. A fuel line 45 extends from the outlet valve 44 to the burner head 14, and a regulator in the form of a valve 46 in the fuel line 45 allows adjust the paraffin feed to the burner head 14 and consequently the intensity of the flame in the burner head. The pump 18 includes a seal in the form of an elastomeric ring 0 between the cylinder 34 and the piston 36. The pump 18 also includes a mass in the form of a ring 50 extending around the cylinder 34, as shown. The ring 50 has a sufficient weight to move the cylinder 34 in the direction of the arrow B to pump paraffin inside the cylinder 34 towards the burner head 14 under
Pressure. The stove 10 also includes a double closure device 52 for controlling the flow of paraffin to the burner head 14 or moving away from the burner head 14. As representatively illustrated in Figure 2 of the drawings, the closure device double 52 can include a ball 54 that can be moved within a chamber 56 between an upper seat 58 and a lower seat 60. In practice, the reservoir 16 is filled with paraffin by removing one of the removable covers 24 and by means of the emptying the paraffin in the tank. The removable cover 24 is then replaced and the cylinder 34 is manually moved in the direction of the arrow A in the position illustrated in Figure 2. As the cylinder 34 is moved upward, the paraffin is pulled towards the cylinder through the port 38 and the inlet valve 40. With the cylinder 34 in the position of Figure 2, the regulator 46 is opened to allow the paraffin to flow towards the burner head 14. The cylinder 34 is then released and the ring 50, in by virtue of its weight, it applies a force to the cylinder, pushing it in the direction of the arrow B. As the cylinder 34 is displaced downward, it applies a pressure on the paraffin inside the cylinder, and the paraffin under pressure is displaced towards the head of burner 14 for fuel combustion and provide thermal energy
in the support 26. During the cooking, the regulator 46 is adjusted in order to provide the desired thermal energy in the support 26, and once the cooking is finished, the flame in the burner head 14 is turned off by closing the regulator 46. The double locking device 52 that serves as a safety device can be conventional in nature. For example, the device 52 can be designed in such a way that the cylinder 34 is moved in the direction of the arrow B, the paraffin moves the ball 54 out of the seat 60 to allow the flow of paraffin to the burner head 14. However, if the flame is suddenly extinguished and a pressure drop occurs in the burner head, the paraffin moves the ball 54 against the seat 58 to close the device and prevent the flow of paraffin to the burner head 14. On the other hand, if the pressure in the burner head 14 rises above a predetermined amount, the ball 54 is displaced against the seat 60 to prevent the flow of paraffin back towards the cylinder 34. The ring 50 can be placed to be located below the center of gravity of the stove 10 such that if the stove is accidentally tilted to one side, the weight of the ring 50 serves to automatically straighten the stove. Alternatively, additional weight can be provided in
the piston 34 or elsewhere in the frame 12 for self-de-erecting the stove 10. The stove may also include curved handles (not shown) extending upwardly from the legs 20 to allow the stove to be transported relatively easily and to prevent the heater from tilting in the cooking vessel holder 26. In an alternative embodiment, the heater 10 may include a paraffin reservoir that is separated from the frame 12 and / or a mechanism, such as a feeding system. lever or pulley, to raise the cylinder or the piston in an operating position. It will be noted that the mass 50 that applies a force on the cylinder 34 to effect the displacement of the cylinder in the direction of the arrow B may be integrated with the cylinder or fixed to the cylinder. Alternatively, the mass 50 may be positioned to apply a force on the cylinder through one or more pulleys, levers or the like. Further, even though the liquid fuel burner has been described above with reference to a piston and cylinder arrangement where the piston 36 is fixed on the frame 12 and the cylinder 34 can move relative to this frame, it will be understood that the burner of liquid fuel may include a cylinder fixed relative to the frame and a displaceable piston.
Figures 3 to 6 of the accompanying drawings illustrating another embodiment of a liquid fuel burner in accordance with the present invention. Similar to the previous embodiment, the liquid fuel burner has the shape of a paraffin heater 110 which includes a frame 112, a burner head 114, a reservoir 116, and a pump 118 for pumping paraffin apart from the reservoir 116 towards the head 114. The frame 112 may include four legs 120 joined at lower ends by a base 122. The legs 120 may be formed apart from the tubular material, such as for example tubular steel sections, with a pair of legs 120 attached to another pair of legs. legs by tubular frame members 124. Frame 112 may also include a cooking vessel holder 126 for supporting pits, pans, and the like (not illustrated) adjacent to burner 114. Support 126 typically comprises an outer ring 128 and four members 130 extending inwardly from the outer ring, as illustrated. In this embodiment of the invention, the support 126 can move vertically relative to the legs 120, and includes guides 132 that engage the legs 120 during a relative movement. Referring also to Figures 2 to 4 of the drawings, the reservoir 116 comprises a generally cylindrical container 134 that includes an opening 136 for filling the container.
with paraffin and a closure 138 for closing the opening 136. The pump 118 may include a cylinder 140 at least partially submerged in the reservoir 116 and a piston 142 that can be displaced relative to the cylinder 140. The piston 14211 takes a seal in the form of a O-elastomeric ring (not shown) for sealing between the piston and the cylinder 140. As representatively illustrated in Figures 4 to 6, the pump 118 may include a one-way valve 144 to allow the paraffin in the reservoir 116 enter the cylinder 140 and a one-way valve 146 to allow the paraffin to exit the cylinder. The one-way valve 144 may include a ball 148 positioned to settle on a plate 150 defining a central opening 152. Similarly, the one-way valve 146 may include a ball 154 and a plate 156 with a central opening 158. As can be seen, the cylinder 140 can communicate with the reservoir 116 through the one way valve 144 and a filter 160. In this embodiment of the invention, the piston 142 is connected to the burner 114 by a piston tube 162 which it carries the one-way valve 146, and the stove 110 includes an adjusting screw 164 for applying a variable resistance to the displacement of the piston 142 relative to the cylinder 140. The adjusting screw 164 can be located within a bushing 166 through which the piston tube 162 is extended. As can be seen in Figures 4 to 6,
the cylinder 140 can communicate with the piston tube 162 through a port 168 in the piston 142. In practice, the reservoir 116 is filled with paraffin by removing the seal 138 and emptying paraffin in the reservoir. The closure 138 is then repositioned and the piston 142 is moved manually relative to the cylinder 140 in the raised position illustrated in Figure 5. As the piston 142 is moved upwardly along the cylinder 140, it pulls the ball 148 of the valve 144 in an open position and causes the paraffin to be introduced into the cylinder 140 through the filter 160 and the one-way valve 144. In the elevated condition of the piston 142, the ball 148 seats in the plate 150 to close the valve 144. Accordingly, a subsequent downward movement of the piston 142 relative to the cylinder 140 causes the paraffin inside the cylinder to be injected through the port 168 and into the piston tube 162. The piston 142, the piston tube 168 and the burner 114 are designed such that they have a sufficient mass to move the piston 142 downward relative to the cylinder 140 when the adjusting screw 164 is disengaged from the piston tube. Accordingly, even with a basin or the like in the holder 126, the piston 142 can slide downwardly inside the cylinder 140 to inject paraffin into the piston tube 162. With a basin or the like in the holder 126, the
adjusting screw, as required, to effect the desired flow of paraffin through the piston tube 162. As the paraffin flows through the piston tube 162, it opens the one-way valve 146, and flows towards the burner head 114 to feed the combustion and provides thermal energy in the support 126. During cooking, the screw 164 can be adjusted to provide the desired thermal energy in the support 126, and once the cooking is complete, the flame in the burner head 114 it can be turned off by blocking the piston 142 relative to the cylinder 140 with the adjusting screw 164. In Figure 6, the burner has been tilted to one side, for example, during incidental tilting of the stove 110. As can be seen, When the heater is inclined, the ball 148 of the valve 144 slides out of the opening 152 in the platen 150 allowing the paraffin to return to the reservoir 116, thereby preventing the paraffin from flowing into the reservoir. Burner head 114 and consequently turning off burner head 114. Figures 7 to 9 illustrate an oven in accordance with a further embodiment of the present invention. In this mode, the stove is similar to stove 110 in all respects except for the design of one-way valves 244 and 246. Therefore, it is not necessary to make a complete description of the stove components outside.
of valves 244 and 246 to fully understand this embodiment of the invention. However, in general terms, the stove includes a reservoir 216, a cylinder 240, a piston 242, a piston tube 262, and a burner head 214 connected to the piston tube. The one-way valve 244 allows the paraffin to enter the cylinder 240, and the one-way valve 246 allows the paraffin to exit the cylinder 240. Similar to the embodiment illustrated in Figures 3 to 6, the stove includes a filter 260 between the reservoir 216 and the cylinder 240, and an adjusting screw 264 for adjusting the intensity of the combustion in the burner head 214. With particular reference to Figure 7, the one-way valve 244 comprises a weighted valve plunger 248 and a valve seat 250 to receive the valve plunger. Similarly, the valve 246 comprises a weighted valve plunger 252 and a valve seat 254. When the piston 242 is displaced relative to the cylinder 240 in the raised condition illustrated in Figure 8, the valve plunger 248 is remote from the valve seat 250 and paraffin is introduced into the cylinder 240. When the piston 242 is in the raised condition, the valve plunger 248 is seated in the valve seat 250 to prevent the paraffin from returning to the reservoir 216. Conform the piston 242 is displaced down relative to cylinder 240,
the paraffin is injected through the piston into the piston tube 262, causing the opening of the one-way valve 246 and the flow of paraffin to the burner head 214. The required combustion intensity in the burner head 214 can be achieved by adjusting the screw 264. Similar to the embodiment illustrated in Figures 3 to 6 of the drawings, if the stove is accidentally tilted to one side, the weighted valve pistons 248 and 252 are tilted from the valve seats 250. and 252 and allow the paraffin to return to the tank 216. The liquid fuel burner may be housed in a frame (not shown) designed to hide the various components of the burner. It will be noted that both embodiments of the invention illustrated in Figures 3 to 9 of the drawings could include a safety device in the form of a double locking device similar to the device 52 described above with reference to Figure 2 of the drawings. Although the invention has been described above with reference to different types of stoves, it will be noted that the liquid fuel burner can be used to provide heat to various other applications such as water heaters, furnaces or heaters.