Oil combustor

Abstract

To provide an oil combustor capable of preventing sound from being generated by a fall of a fuel into a pot after fire extinction.SOLUTION: An oil combustor comprises: a pot 4 including a number of air holes 4a on a sidewall; a wind tunnel 3 in which the pot 4 is disposed; a combustion fan 5 which is connected to the wind channel 3 and supplies combustion air to the pot 4; and a fuel pump 8 which supplies a fuel in a fuel storage part 7 to the pot 4. A high place A is included in a fuel pipe 9 connecting the pot 4 and the fuel pump 8, and a region from the high place A to a fuel nozzle 9a is made into a downward gradient. A same-pressure hose 17 is connected to the combustion fan 5 and the fuel storage part 7, and an air pipe 18 is connected to the fuel storage part 7 and the high place A of the fuel pipe 9. A control device 13 stops the fuel pump 8 upon receiving a fire extinction signal, sets the combustion fan 5 to a predetermined rotation speed, sets the combustion fan 5 to a second predetermined rotation speed in accordance with a signal of flame non-detection from flame detection means 16, and stops the combustion fan 5 after the lapse of a preset time. Thus, the fuel in the fuel pipe 9 is extruded, such that no fuel remains.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an oil burner that burns liquid fuel for heating. [Background technology]

[0002] A pot-type oil burner comprises a pot with numerous air holes in its side wall, a combustion fan that supplies combustion air to the pot, a fuel storage section that stores fuel, and a fuel pump that supplies fuel from the fuel storage section to the pot. A fuel pipe is connected between the fuel pump and the pot, and fuel from the fuel storage section is supplied to the pot by the fuel pump, and air is supplied through the air holes in the side wall of the pot by the combustion fan.

[0003] In a pot-type oil burner, if fuel remaining in the fuel pipe is supplied to the pot even after the fuel pump has stopped and the fuel supply has stopped when the fire is extinguished, it takes a long time for all the fuel in the pot to burn out and the fire to be extinguished, and during this time an odor may be generated. Also, if fuel remains in the fuel pipe, it may fall into the pot after the fire is extinguished, and because the bottom of the pot is still hot at this time, the heat of the pot may cause the fuel to vaporize, generating a loud noise, which can be very annoying.

[0004] To address this issue, some systems connect an air pipe to the fuel pipe, to which the air pressure of the combustion fan is applied, and provide an elevated location in the fuel pipe from the junction of the fuel pipe and air pipe to the pot (see Patent Document 1). Other systems also have a suction pump attached to the fuel pipe, separate from the fuel pump (see Patent Document 2). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-213741 [Patent Document 2] Japanese Patent Application Laid-Open No. 2005-42934 Summary of the Invention [Problem to be solved by the invention]

[0006] In the device of Patent Document 1, when the fuel pump stops and the fuel supply stops during fire extinguishing, the fuel in the fuel pipe is sucked into the air pipe over a high place, preventing fuel from being supplied into the pot, thereby shortening the time until the fire is extinguished. In addition, the fuel in the fuel pipe is prevented from falling into the pot after the fire is extinguished.

[0007] In the device disclosed in Patent Document 2, after the fuel pump stops and the fuel supply is stopped when the fire is extinguished, the suction pump is driven to suck up the fuel remaining in the fuel pipe, preventing fuel from being supplied into the pot, thereby shortening the time until the fire is extinguished. In addition, the fuel in the fuel pipe is prevented from falling into the pot after the fire is extinguished.

[0008] However, in the case of Patent Document 1, the shape of the fuel pipe becomes complicated, and in the case of Patent Document 2, a suction pump must be provided in addition to the fuel pump, and in both cases there are problems with the number of parts and processing costs, which increase production costs.

[0009] An object of the present invention is to provide an oil burner that has a simple structure, yet stabilizes the time until the fire is extinguished, and prevents noise from being generated after the fire is extinguished. [Means for solving the problem]

[0010] The present invention solves the above-mentioned problems, and provides an oil burner (1) comprising a pot (4) having a number of air holes (4a) on a side wall, a wind tunnel (3) in which the pot (4) is placed, a combustion fan (5) connected to the wind tunnel (3) to supply combustion air to the pot (4), a fuel reservoir (7) for storing fuel, a fuel pump (8) for supplying fuel from the fuel reservoir (7) to the pot (4), and a fuel pipe (9) connecting the pot (4) and the fuel pump (8), wherein a fuel nozzle (9a) at the tip of the fuel pipe (9) is positioned inside the pot (4), and the fuel from the fuel reservoir (7) is supplied to the pot (4) by the fuel pump (8), and the fuel pipe (9) is provided with a high point (A), A downward slope is provided from A to the fuel nozzle 9a, and the oil burner is provided with a pressure equalizing hose 17 connecting the combustion fan 5 and the fuel storage section 7, an air pipe 18 connecting the fuel storage section 7 and the high point A of the fuel pipe 9, and a flame detection means 16 for detecting the presence or absence of a flame in the pot 4, and the control device 13 stops the fuel pump 8 and sets the combustion fan 5 to a predetermined rotation speed upon receiving a signal from the flame detection means 16 that no flame is detected, sets the combustion fan 5 to a second predetermined rotation speed upon receiving a signal from the flame detection means 16 that no flame is detected, and stops the combustion fan 5 after a set time has elapsed since setting the combustion fan to the second predetermined rotation speed.

[0011] Furthermore, the control device 13 is configured to change the rotation speed of the combustion fan 5 to the predetermined rotation speed if the rotation speed of the combustion fan 5 at the time of receiving the extinguishing signal is lower than a predetermined rotation speed, and to maintain the rotation speed of the combustion fan 5 if the rotation speed of the combustion fan 5 at the time of receiving the extinguishing signal is equal to or higher than the predetermined rotation speed. By setting the rotation speed of the combustion fan 5 to a predetermined rotation speed or higher, the fuel remaining in the fuel pipe 9 can be reliably pushed out into the pot 4. [Effects of the Invention]

[0012] According to the present invention, by forcibly pushing out the fuel remaining in the fuel pipe 9 when the fire is extinguished, the fuel in the pot 4 can be burned in a short time, and the time until the fire is extinguished can be stabilized. Furthermore, because no fuel remains in the fuel pipe 9, the fuel does not fall from the fuel pipe 9 after the fire is extinguished, and no loud noise is generated after the fire is extinguished. Furthermore, by simplifying the shape of the fuel pipe 9, it is possible to reduce the number of parts and processing costs, thereby realizing a reduction in production costs. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a block diagram showing the configuration of an oil burner according to an embodiment of the present invention. [Figure 2] 1 is a cross-sectional view of an oil burner showing an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, an embodiment of an oil burner of the present invention will be described with reference to the drawings.

[0015] Fig. 1 is a block diagram showing the configuration of an oil burner according to an embodiment of the present invention, and Fig. 2 is a cross-sectional view of the oil burner according to the embodiment of the present invention. The oil burner 1 has a frame 2, an air tunnel 3 provided within the frame 2, a pot 4 installed within the air tunnel 3, and a combustion fan 5 that supplies combustion air to the pot 4. The combustion fan 5 and the air tunnel 3 are connected by an air flow path 6. The pot 4 is formed in a cylindrical shape with a bottom and has multiple air holes 4a on its side wall. Air sent to the air tunnel 3 by the combustion fan 5 passes through the air holes 4a and is supplied into the pot 4.

[0016] A constant oil level monitor 7 that serves as a fuel storage section for fuel is provided within the frame 2. The constant oil level monitor 7 is connected to a fuel tank installed outside the oil burner 1 by a fuel pipe 7a, and when fuel is sent from the fuel tank through the fuel pipe 7a and rises to a set oil level, a built-in float valve closes the inlet, and when the fuel in the constant oil level monitor 7 is sent to the pot 4 and the oil level drops, the float valve opens the inlet and fuel is sent from the fuel tank, thereby maintaining the set oil level inside the constant oil level monitor 7.

[0017] A fuel pump 8 is attached to the constant oil leveler 7, and a fuel pipe 9 is provided which connects the fuel pump 8 to the pot 4. An oil supply nozzle 9a is formed at the end of the fuel pipe 9, and the fuel pipe 9 is attached by passing through the side wall of the wind tunnel 3 and the pot 4, with the oil supply nozzle 9a located inside the pot 4.

[0018] The pot 4 is provided with an ignition heater 10. The ignition heater 10 is made up of a rod-shaped ceramic heater, and is attached to the side wall of the pot 4 and arranged above the bottom surface of the pot 4 at a predetermined distance.

[0019] The operating section of the frame 2 is equipped with an operation switch 11 for instructing the operation and stop of the oil burner 1, and a temperature setting switch 12. Inside the frame 2, a control device 13 incorporating a microcomputer for controlling the operation of the oil burner 1 is arranged.

[0020] When operation switch 11 is pressed, an operation start signal is sent to control device 13, which then energizes ignition heater 10 to heat pot 4, and when it determines that the temperature inside pot 4 has reached an ignition-safe temperature, it drives combustion fan 5 and fuel pump 8 to supply combustion air and fuel to pot 4. The fuel supplied to pot 4 vaporizes at the bottom of pot 4, which has become hot, and is ignited by the heat of ignition heater 10, starting combustion.

[0021] A flame detection means 16 is provided at a position inside the pot 4 where the flame hits, and when the flame detection means 16 detects a flame inside the pot 4 and outputs a flame detection signal, the control device 13 stops the supply of electricity to the ignition heater 10.

[0022] When combustion begins in the pot 4, the fuel dripping from the fuel supply nozzle 9a vaporizes at the bottom of the pot 4, which has become hot due to the heat of combustion, and part of the vaporized gas is burned by the combustion air supplied from the air hole 4a.The generated combustion gas and the remaining vaporized gas are completely burned in the combustion chamber 14 located at the top of the pot 4.

[0023] The oil burner 1 is provided with a room temperature sensor 15 on the back of its frame 2, and the control device 13 compares the temperature set by the temperature setting switch 12 on the operating unit with the room temperature detected by the room temperature sensor 15. If the room temperature is lower than the set temperature, the control device 13 increases the number of revolutions of the combustion fan 5 and the flow rate of the fuel pump 8 to increase the amount of combustion, and if the room temperature is higher than the set temperature, the control device 13 decreases the number of revolutions of the combustion fan 5 and the flow rate of the fuel pump 8 to decrease the amount of combustion, thereby controlling the room temperature to approach the set temperature.

[0024] The oil burner 1 has minimum and maximum combustion levels and multiple combustion levels in between. In this embodiment, there are five combustion levels from minimum combustion level N1 to maximum combustion level N5, and the combustion fan 5 and fuel pump 8 are set to operate at rotation speeds and flow rates corresponding to each combustion level.

[0025] As shown in Fig. 2, the oil burner 1 of this embodiment is provided with a pressure equalizing hose 17 that connects the combustion fan 5 and the oil level controller 7, and an air pipe 18 that connects the oil level controller 7 and the fuel pipe 9. One end of the pressure equalizing hose 17 is connected to the combustion fan 5, and the other end is connected to the top surface of the oil level controller 7, and is in communication with the space above the oil level in the oil level controller 7.

[0026] In addition, the fuel pipe 9 is extended upward from the fuel pump 8 and then bent into a U-shape to form a high point A, and is connected to the side wall of the pot 4 at a downward slope from the high point A. One end of the air pipe 18 is connected to the top surface of the oil level regulator 7 and communicates with the space inside the oil level regulator 7, and the other end is connected to the high point A of the fuel pipe 9.

[0027] When combustion fan 5 is driven and combustion air is sent to wind tunnel 3, a portion of the combustion air is sent into constant oil level 7 by pressure equalization hose 17, and the air in the space inside constant oil level 7 is sent to fuel pipe 9 through air pipe 18. When combustion fan 5 is driven, the pressure inside wind tunnel 3 becomes higher than that inside pot 4, and the higher the rotation speed of combustion fan 5, the greater the pressure difference between wind tunnel 3 and pot 4. By connecting pressure equalization hose 17 to equalize the pressure inside wind tunnel 3 and constant oil level 7 as in the present invention, a higher pressure can be applied to fuel pipe 9 than inside pot 4, pushing the fuel in fuel pipe 8 into pot 4.

[0028] When the operation switch 11 is pressed while the oil burner 1 is in operation and an operation stop signal is sent to the control device 13, the control device 13 stops the fuel pump 8 to cut off the supply of fuel to the pot 4 and changes the rotation speed of the combustion fan 5 to a predetermined rotation speed. In this embodiment, the combustion amount when the operation stop signal is output is confirmed, and if the combustion amount is equal to or greater than N3, which is medium combustion, the combustion fan 5 is driven at the rotation speed corresponding to the combustion amount N3 to N5, but if the combustion amount is N1 or N2, which is lower than the combustion amount N3, the rotation speed is changed to correspond to the combustion amount N3 and driven.

[0029] After the fuel pump 8 is stopped, the fuel in the pot 4 burns out, the flame becomes smaller, and the flame detection means 16 is no longer able to detect the flame, so a flame non-detection signal is output. When this occurs, the rotation speed of the combustion fan 5 is changed to a predetermined rotation speed. In this embodiment, if the rotation speed of the combustion fan 5 corresponds to the combustion amount N3, it is driven at the rotation speed corresponding to the combustion amount N3, and if the rotation speed corresponds to the combustion amount N4 or N5, it is changed to the rotation speed corresponding to the combustion amount N3.

[0030] After the flame detection means 16 outputs a signal indicating that a flame has not been detected, the combustion fan 5 is stopped from driving when a preset time has elapsed.

[0031] By driving the combustion fan 5 at a speed equal to or greater than the rotational speed corresponding to the combustion amount N3, a constant pressure difference is maintained between the wind tunnel 3 and the pot 4, and any fuel remaining in the fuel pipe 9 can be pushed into the pot 4 in a short time even after the fuel pump 8 has stopped. Since no fuel remains in the fuel pipe 9, the fire can be extinguished once all the fuel in the pot 4 has burned out. This solves the problem of fuel remaining in the fuel pipe 9 being supplied to the pot 4 during the extinguishing operation, lengthening the extinguishing time, and stabilizes the extinguishing time. In addition, fuel no longer falls into the pot 4 after the fire has been extinguished, eliminating the generation of loud noises.

[0032] When the combustion amount is N4 to N5, the combustion fan 5 operates at the same rotation speed corresponding to the combustion amount N4 to N5, so the noise is louder than when the rotation speed corresponds to the combustion amount N3. However, since the volume of the noise of the combustion fan 5 does not change, the noise is not bothersome, and the rotation speed of the combustion fan 5 is set so that the fuel remaining in the fuel pipe 9 can be reliably pushed out into the pot 4.

[0033] On the other hand, when the combustion amount is N1 or N2, if the combustion fan 5 remains at the rotation speed corresponding to the combustion amounts N1 to N2, there is a possibility that the force required to push the fuel remaining in the fuel pipe 9 into the pot 4 will be insufficient, so the rotation speed of the combustion fan 5 is changed to the rotation speed corresponding to the combustion amount N3 so that the fuel remaining in the fuel pipe 9 can be pushed out. In this case, the noise level increases slightly as the rotation speed of the combustion fan 5 increases, but the change in noise level is kept to a level that is not noticeable.

[0034] In addition, the oil burner 1 of this embodiment is a type in which fuel is supplied from an externally installed fuel tank and the fuel storage section is composed of a constant oil level device 7, but this is not limited to this and it can also be applied to a cartridge tank type in which the fuel storage section is composed of an oil pan. [Explanation of symbols]

[0035] 1 Oil burner 3 Wind tunnel 4 pots 4a Air vent 5 Combustion fan 7 Fuel storage section 8. Fuel pump 9 Fuel Pipe 9a Fuel nozzle A. High places 13 Control device 16 Flame detection means 17 Equal pressure hose 18 Air Pipe

Claims

1. a pot having a number of air holes in a side wall; a wind tunnel in which the pot is placed; and a combustion fan connected to the wind tunnel to supply combustion air to the pot; a fuel reservoir for storing fuel; a fuel pump for supplying fuel from the fuel reservoir to the pot; and a fuel pipe for connecting the pot and the fuel pump, In an oil burner, a fuel nozzle at the tip of the fuel pipe is positioned inside the pot, and fuel from the fuel reservoir is supplied to the pot by the fuel pump, the fuel pipe has an elevated portion and a downward slope from the elevated portion to the fuel nozzle; a pressure equalizing hose that connects the combustion fan and the fuel storage unit, and an air pipe that connects the fuel storage unit and a high position of the fuel pipe; a flame detection means for detecting the presence or absence of a flame in the pot; The control device stops the fuel pump and sets the combustion fan to a predetermined rotation speed upon receiving a fire extinguishing signal, sets the combustion fan to a second predetermined rotation speed upon receiving a signal indicating no flame is detected from the flame detection means, and stops the combustion fan after a set time has elapsed since setting the combustion fan to the second predetermined rotation speed.

2. The oil burner according to claim 1, characterized in that the control device changes the rotation speed of the combustion fan to the predetermined rotation speed when the rotation speed of the combustion fan at the time of receiving the fire extinguishing signal is lower than the predetermined rotation speed, and maintains the rotation speed of the combustion fan when the rotation speed of the combustion fan at the time of receiving the fire extinguishing signal is equal to or higher than the predetermined rotation speed.

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