Oil-burning appliances

Abstract

To provide a petroleum combustor capable of preventing a time for extinguishing fire from becoming longer, which is caused by a liquid fuel dripping into a pot when fire is being extinguished.SOLUTION: A controller of a petroleum combustor stops an electromagnetic pump 4 that feeds liquid fuel upon starting fire extinguishing, opens an on-off valve 21 subsequent to maximization of the rotation rate of a combustion fan 8 that feeds combustion air, closes the on-off valve 21 subsequent to a lapse of an on-off valve opening time after opening the on-off valve 21, and thereafter stops the combustion fan 8, whereby the inner pressure of a pot is prevented from becoming negative by maximizing the rotation rate of the combustion fan 8, and liquid fuel remaining in a fuel feed pipe 5 can be returned to and recovered in a constant oil level device 16 by a drop between the nozzle 6 of the oil feed pipe 5 and the constant oil level device 16 by opening the on-off valve 21.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to oil-burning appliances. [Background technology]

[0002] Conventionally, in this type of device, an oil supply pipe that supplies liquid fuel from the constant oil level device to the pot and the space inside the constant oil level device are connected by an air pipe with an opening and closing valve, and the opening and closing valve is opened at the same time as the fire is extinguished, so that the liquid fuel remaining in the oil supply pipe is sucked and collected at the same time as the fire is extinguished (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2000-146120 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the conventional system, when an intake and exhaust pipe or chimney is connected to an oil burning appliance and the combustion gas generated by burning liquid fuel is exhausted outdoors, if a strong wind blows around the tip of the intake and exhaust pipe or chimney, the exhaust gas in the intake and exhaust pipe or chimney will be pulled by the strong wind, creating negative pressure inside the pot. When this negative pressure is reached and the fire is extinguished and the on-off valve is opened at the same time as the fire extinguishing operation, the liquid fuel in the fuel supply pipe will be pulled toward the pot due to the negative pressure inside the pot and will not return completely to the oil level controller, and the liquid fuel in the fuel supply pipe will drip into the pot, lengthening the extinguishing time, or liquid fuel may remain in the fuel supply pipe, causing the nozzle at the end of the fuel supply pipe to become clogged. [Means for solving the problem]

[0005] In order to solve the above problem, claim 1 of the present invention provides an oil burning appliance comprising a pot having a number of air holes around it, an air chamber surrounding the pot, a combustion fan that sends combustion air to the air chamber, a constant oil level device that stores a certain amount of liquid fuel, an electromagnetic pump that supplies the liquid fuel in the constant oil level device to the pot, a fuel supply pipe that connects the electromagnetic pump to the pot and has a nozzle at its end located within the pot and the nozzle is positioned at a higher height than the constant oil level device, an opening / closing valve located between the nozzle and the constant oil level device, a timer that measures time, and a control unit that performs oil return control by opening the opening / closing valve when extinguishing a fire and returning the liquid fuel in the fuel supply pipe to the constant oil level device, wherein the control unit stops the electromagnetic pump when extinguishing a fire, opens the opening / closing valve after the combustion fan is rotated at its maximum speed, and closes the opening / closing valve after the opening / closing valve opening time has elapsed, and stops the combustion fan.

[0006] Moreover, in claim 2, the control unit stops the electromagnetic pump when extinguishing starts, and sets the combustion fan to the maximum rotation speed, opens the on-off valve after an on-off valve standby time has elapsed since stopping the electromagnetic pump, closes the on-off valve after the on-off valve open time has elapsed since opening the on-off valve, and stops the combustion fan after a maximum rotation speed duration time has elapsed since the on-off valve is closed. Effect of the Invention

[0007] According to claim 1 of this invention, when extinguishing begins, the electromagnetic pump is stopped, the combustion fan is set to its maximum rotation speed and then the on-off valve is opened, and after the on-off valve open time has elapsed since it was opened, the on-off valve is closed and the combustion fan is stopped. By setting the combustion fan to its maximum rotation speed, it is possible to prevent negative pressure from building up inside the pot, and by opening the on-off valve, the liquid fuel remaining in the fuel supply pipe can be returned to the constant oil level by the drop between the nozzle of the fuel supply pipe and the constant oil level regulator, and recovered.

[0008] According to claim 2, when extinguishing begins, the electromagnetic pump is stopped and the combustion fan is rotated at its maximum speed, and the on-off valve is opened after the on-off valve standby time has elapsed since the electromagnetic pump was stopped. Therefore, the combustion fan is rotated at its maximum speed to create a state in which there is no negative pressure inside the pot, and then the on-off valve is opened. This makes it easier for liquid fuel remaining in the fuel supply pipe to return to the constant oil level due to the difference in head between the nozzle of the fuel supply pipe and the constant oil level regulator, and also makes it difficult for liquid fuel to drip from the tip of the nozzle, preventing the extinguishing time from being prolonged.

[0009] In addition, the on-off valve is closed after the on-off valve open time has elapsed since it was opened, and the combustion fan is stopped after the maximum rotation speed duration time has elapsed since the on-off valve was closed, so that negative pressure is prevented again from building up inside the pot until the liquid fuel remaining in the fuel supply pipe returns to the constant oil level device, and the liquid fuel remaining in the fuel supply pipe can be more reliably returned to the constant oil level device. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic configuration diagram of an oil burning appliance showing one embodiment of the present invention. [Diagram 2] The same block diagram. [Diagram 3] FIG. 4 is a flowchart illustrating the oil return control during extinguishing. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Next, an embodiment of the present invention will be described with reference to the drawings. Reference numeral 1 denotes an oil-burning appliance, and is equipped with a pot-type combustor 2 that burns liquid fuel to produce combustion gas. The pot-type combustor 2 includes a pot 3, an electromagnetic pump 4 that supplies liquid fuel to the pot 3, a fuel supply pipe 5, a nozzle 6 at the tip of the fuel supply pipe 5, an ignition heater 7 that preheats and ignites the fuel, and a combustion fan 8 that supplies combustion air to the pot 3.

[0012] The pot 3 is formed in a cylindrical shape with a bottom, and a large number of primary air holes 9 and secondary air holes 10, which are circular through holes, are drilled in the peripheral wall as air holes. The outer periphery of the pot 3 is surrounded by an outer cylinder 11, and an air chamber 12 is formed between them. The combustion fan 8 supplies air into the pot 3 through an air chamber 12, a primary air hole 9 and a secondary air hole 10.

[0013] Reference numeral 13 denotes a flame equalizer, which is fixed in the center of the pot 3 and promotes mixing of the vaporized gas and the combustion air. Reference numeral 14 denotes an evaporation net, which is made of woven heat-resistant stainless steel wires to generate capillary action, and is fixed to the center of the bottom of pot 3.

[0014] The ignition heater 7 is composed of a rod-shaped ceramic heater and protrudes from the peripheral wall of the pot 3 toward above the vaporization screen 14. This ignition heater 7 has both the function of preheating and vaporizing the liquid fuel and the function of igniting the vaporized liquid fuel.

[0015] The nozzle 6 is constituted by a thin pipe that slopes downward into the pot 3 , and when liquid fuel is supplied, the nozzle 6 sprays the liquid fuel toward the vaporizing screen 14 . Reference numeral 15 denotes a protective tube, which is formed in a cylindrical shape so as to cover the periphery of the nozzle 6. One end of the protective tube 15 is fixed to the outer tube 11, and the other end penetrates the side wall of the pot 3 and is exposed inside.

[0016] Reference numeral 16 denotes a constant oil level regulator, which maintains oil from a fuel tank 17 installed outdoors at a constant level, and liquid fuel is supplied to the oil level regulator by a pump 19 via a pumping pipe 18. Moreover, the nozzle 6 is disposed at a higher position than the constant oil level device 16 . Reference numeral 20 denotes a top lid which covers the top surface of the constant oil level device 16, and to which the pumping pump 19 and the electromagnetic pump 4 which supplies the liquid fuel in the constant oil level device 16 to the pot 3 via the fuel supply pipe 5 and nozzle 6 are fixed.

[0017] An on-off valve 21 is built in the electromagnetic pump 4, and the on-off valve 21 is opened when the fire is extinguished. When the on-off valve 21 is opened, the liquid fuel remaining in the fuel supply pipe 5 and the nozzle 6 returns from a cylinder (not shown) in the electromagnetic pump 4 to the constant oil level device 16, thereby preventing the fuel from dripping into the pot 3 when the fire is extinguished.

[0018] Reference numeral 22 denotes a flame rod, which is suspended within the pot 3 so as to be positioned within the combustion flame during combustion, and which detects ignition, misfire, abnormal combustion, etc. A temperature sensor 23 detects the temperature at the bottom of the pot 3 , and is constituted by a thermistor and is fixed in contact with the back side of the bottom of the pot 3 . Reference numeral 24 denotes a tachometer, which measures the rotation speed of the combustion fan 8 .

[0019] Reference numeral 25 denotes a glass outer cylinder provided on the top of the pot 3, and radiant heating is provided by a red-hot cylinder 26 located at the upper part of the glass outer cylinder 25, which is heated by combustion gas produced by burning liquid fuel in the pot 3. Reference numeral 27 denotes a heat exchanger which exchanges heat between the gas exhausted from the glass outer cylinder 25 and the air in the living room blown by a convection fan 28, and blows the hot air into the room.

[0020] Numeral 29 denotes an exhaust pipe which is connected to an exhaust section (not shown) of the intake and exhaust pipe or a chimney (not shown) and which exhausts the gas exhausted from the glass outer cylinder 25 to the outdoors. Reference numeral 30 denotes a room temperature sensor which detects the room temperature.

[0021] Reference numeral 31 denotes a control unit, which is mainly composed of a microcomputer and controls the combustion operation in the pot-type combustor 2 and the resulting heating operation. Reference numeral 32 denotes an operation unit having various operation switches such as an operation switch (not shown) for instructing the on / off state of the heating operation and a room temperature setting switch (not shown) for setting a desired room temperature.

[0022] Reference numeral 33 denotes a display unit which displays various information such as the on / off state of the heating operation, the set temperature set by the room temperature setting switch, the room temperature detected by the room temperature sensor 30, and warnings, abnormalities, etc. Reference numeral 34 denotes a timer which starts timing in response to a timing start signal input from the control unit 31, and stops timing in response to a timing stop signal input from the control unit 31. When the timer starts timing and a predetermined time has elapsed, it outputs a timing signal to the control unit 31, and resets the timing time when a reset signal is input from the control unit 31 or when the timer starts timing and a predetermined time has elapsed.

[0023] Reference numeral 35 denotes an oil level detection means which is provided within the oil level controller 16 and which outputs an oil supply start signal when the oil level within the oil level controller 16 falls to the oil supply start height, and outputs an oil supply stop signal when the oil level within the oil level controller 16 rises to the oil supply stop height, thereby causing the control unit 31 to control the operation of the pumping pump 19.

[0024] Next, the control of extinguishing the oil burning appliance will be described with reference to the flow chart of FIG. When the operation switch of the operation unit 32 is turned OFF during operation (S1), the control unit 31 performs a fire extinguishing operation to stop combustion. First, the control unit 31 stops the electromagnetic pump 4 that supplies liquid fuel to the pot 3 (S2). Then, the rotation speed of the combustion fan 8 is increased to the maximum rotation speed (S3), and an on-off valve standby time counting start signal is output to the timer 34, and the timer 34 starts counting time (S4).

[0025] By setting the rotation speed of the combustion fan 8 to the maximum rotation speed in (S3), the inside of the pot-type combustor 2 is pressurized by the combustion fan 8, and it is possible to prevent negative pressure from occurring inside the pot 3 even if a strong wind blows around the tip of the intake and exhaust pipe or chimney connected to the exhaust pipe 29.

[0026] When the time counted by the timer 34 reaches or exceeds the on-off valve standby time, the timer 34 outputs an on-off valve standby time counting signal to the control unit 31 (S5). The control unit 31, which has received the on-off valve standby time counting signal, outputs a counting stop signal and a reset signal to the timer 34, thereby stopping and resetting the timer 34 (S6).

[0027] Then, the control unit 31 opens the on-off valve 21 in the electromagnetic pump 4 (S7). By allowing the on-off valve standby time to elapse with the combustion fan 8 rotating at its maximum speed, the inside of the pot 3 is sufficiently pressurized, and by opening the on-off valve 21 in the electromagnetic pump 4 after the on-off valve standby time has elapsed, the liquid fuel remaining in the pipe from the nozzle 6, which is located at a higher position than the constant oil level device 16, to the fuel supply pipe 5 passes through the cylinder in the electromagnetic pump 4 and returns to the constant oil level device 16 due to the difference in head between the nozzle 6 and the fuel supply pipe 5 and the constant oil level device 16, preventing fuel from dripping into the pot 3 when the fire is extinguished.

[0028] Then, the control unit 31 outputs a signal to start counting the open / close valve time to the timer 34, and the timer 34 starts counting time (S8). When the time counted by the timer 34 reaches or exceeds the on-off valve open time, the timer 34 outputs an on-off valve open time count signal to the control unit 31 (S9). The control unit 31, which has received the on-off valve standby time counting signal, outputs a counting stop signal and a reset signal to the timer 34, thereby stopping and resetting the timer 34 (S10).

[0029] Then, the control unit 31 closes the on-off valve 21 in the electromagnetic pump 4 (S11), and outputs a maximum rotation speed duration time counting start signal to the timer 34, and the timer 34 starts counting time (S12). When the time counted by the timer 34 reaches or exceeds the maximum rotation speed duration, the timer 34 outputs a maximum rotation speed duration count signal to the control unit 31 (S13).

[0030] The control unit 31, which has received the maximum rotation speed continuation timing signal, outputs a timing stop signal and a reset signal to the timer 34, thereby stopping and resetting the timer 34 (S14). Then, the control unit 31 stops the combustion fan 8 at the maximum rotation speed (S15) and ends the oil return control during extinguishing (S16).

[0031] In this way, the on-off valve 21 in the electromagnetic pump 4 is closed and then the combustion fan 8, which is rotating at the maximum speed, is stopped. Therefore, the inside of the pot 3 is sufficiently pressurized until the on-off valve 21 in the electromagnetic pump 4 is completely closed, and the liquid fuel remaining in the fuel supply pipe 5 does not drip into the pot 3, and the liquid fuel remaining in the fuel supply pipe 5 can be reliably returned to the constant oil level device 16.

[0032] As described above, when extinguishing begins, the electromagnetic pump 4 is stopped, the combustion fan 8 is set to the maximum rotation speed, the on-off valve 21 of the electromagnetic pump 4 is opened, and after the on-off valve open time has elapsed since the on-off valve 21 was opened, the on-off valve 21 is closed and the combustion fan 8 is stopped. By setting the combustion fan 8 to the maximum rotation speed, it is possible to prevent negative pressure from building up inside the pot 3, and by opening the on-off valve 21 and using the drop between the nozzle 6 of the fuel supply pipe 5 and the constant oil level monitor 16, the liquid fuel remaining in the fuel supply pipe 5 can be returned to the constant oil level monitor 16 and recovered.

[0033] In addition, when extinguishing begins, the electromagnetic pump 4 is stopped and the combustion fan 8 is rotated at the maximum speed, and the on-off valve 21 is opened after the on-off valve standby time has elapsed since the electromagnetic pump 4 was stopped. Therefore, the combustion fan 8 is rotated at the maximum speed to create a state in which the inside of the pot 3 is not under negative pressure, and then the on-off valve 21 is opened, so that the difference in head between the nozzle 6 of the fuel supply pipe 5 and the constant oil level regulator 16 makes it easier for the liquid fuel remaining in the fuel supply pipe 5 to return to the constant oil level regulator 16, and also makes it difficult for liquid fuel to drip from the tip of the nozzle 6, thereby preventing the extinguishing time from being long.

[0034] In addition, the on-off valve 21 is closed after the on-off valve open time has elapsed since it was opened, and the combustion fan 8 is stopped after the maximum rotation speed duration time has elapsed since the on-off valve 21 was closed, so that negative pressure is prevented again from building up inside the pot 3 until the liquid fuel remaining in the fuel supply pipe 5 returns to the constant oil level device 16, and the liquid fuel remaining in the fuel supply pipe 5 can be more reliably returned to the constant oil level device 16.

[0035] In this embodiment, the on-off valve 21 is built into the electromagnetic pump 4, but the present invention is not limited to this. The on-off valve 21 may be provided between the nozzle 6 and the oil level regulator 16. For example, an oil return pipe may be provided having one end connected to the oil supply pipe 5 and the other end connected to the oil level regulator 16, and an on-off valve 21 may be provided on this oil return pipe. [Explanation of symbols]

[0036] 3 Pot 4. Electromagnetic pump 5. Fuel Pipe 6 Nozzles 8 Combustion fan 9, 10 Air vents 12 Air chamber 16 Oil level gauge 21 On-off valve 31 Control Unit 34 Timer

Claims

1. an oil burning appliance comprising a pot having a number of air holes around it, an air chamber surrounding the pot, a combustion fan which sends combustion air to the air chamber, a constant oil level device which stores a fixed amount of liquid fuel, an electromagnetic pump which supplies the liquid fuel in the constant oil level device to the pot, an oil supply pipe which connects the electromagnetic pump to the pot and has a nozzle at its end located within the pot with the nozzle positioned at a higher position than the constant oil level device, an on-off valve which is located between the nozzle and the constant oil level device, a timer which measures time, and a control unit which performs oil return control by opening the on-off valve when a fire is extinguished and returning the liquid fuel in the oil supply pipe to the constant oil level device, wherein the control unit stops the electromagnetic pump when extinguishing the fire, and opens the on-off valve after the combustion fan reaches its maximum rotation speed, and closes the on-off valve after the on-off valve opening time has elapsed since the on-off valve was opened, and stops the combustion fan,

2. The oil burning appliance according to claim 1, characterized in that the control unit stops the electromagnetic pump when extinguishing begins and sets the combustion fan to its maximum rotation speed, opens the on-off valve after an on-off valve standby time has elapsed since stopping the electromagnetic pump, closes the on-off valve after the on-off valve open time has elapsed since opening the on-off valve, and stops the combustion fan after a maximum rotation speed duration has elapsed since the on-off valve is closed.

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