CA2800473C

CA2800473C - Firewood boiler

Info

Publication number: CA2800473C
Application number: CA 2800473
Authority: CA
Inventors: Ha Yeon Jang
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-05-27
Filing date: 2011-05-19
Publication date: 2015-04-14
Anticipated expiration: 2031-05-19
Also published as: JP2013531775A; EP2578934A4; JP5723974B2; WO2011149217A3; WO2011149217A2; KR101006146B1; CA2800473A1; US20130068174A1; EP2578934A2

Abstract

The present invention relates to a firewood boiler, comprising: a boiler main body including a feeding hole through which wood fuel and air for combustion are fed, a smoke exhaust hole defined in the top thereof so as to be connected to an exhaust pipe, an air inlet defined adjacent to the smoke exhaust hole, and a heating-water store in which heating water is stored; a main opening/closing unit installed on the boiler main body to open and close the feeding hole and selectively supply and block the entry of outside air into the boiler main body when the feeding hole is closed; an auxiliary opening/closing unit for supplying outside air into the boiler main body when the entry of outside air is blocked by the main opening/closing unit; a temperature sensor for sensing the temperature of the heating water; and a control unit for controlling the inflow and blocking of air by means of the main opening/closing unit on the basis of information on the temperature sensed by the temperature sensor. The heating water store is integrally formed along the entirety of the boiler main body, and the auxiliary opening/closing unit maintains a pilot flame for the wood fuel by supplying outside air into the boiler main body when the main opening/closing unit blocks the entry of outside air. Thus, a firewood boiler may be provided that can be safely used for a long period of time without extinguishing a pilot flame.

Description

FIREWOOD BOILER
Technical Field [1] The present invention relates to a firewood boiler, and in particular to a firewood boiler which is configured to generate heat energy using wood as a main fuel.
Backdround Art

[2] A boiler has features in that it heats water of a room temperature using a combustion heat that is generated as an energy source combusts, and the thusly heated water circulates along a pipe embedded in the indoor floor, thus heating the floor or the heated water can be used for the sake of a hot water supply. Depending on the energy source combusted so as to obtain the heat energy, there are an electric boiler, a gas boiler, an oil boiler and an oil-shared electric boiler having the advantages of oil and gas.

[3] For the gas boiler, the electric boiler and the oil-shared electric boiler, it is easy to control the functions of ignition, combustion and fire extinguishing, so they are widely used for household and facility purposes.

[4] In recent years, the energy prices of electricity and oil continue to increase, and in case of Korea, most of those fuels are imported from abroad owing to the lack of local energy resources. Thus, the uses of such boilers might result in a higher economic burden.

[5] Therefore, the developments of alternative energy are widely performed. As one of such developments, there is a firewood boiler configured to use wood which can be easily obtained locally at a lower cost.

[6] The above-mentioned firewood boiler has the problems in that it is impossible to freely supply the energy source and stop the supply of it like electricity and oil due to the combustion characteristics of the wood which is a main energy source, and it is hard to control the ignition, combustion and fire extinguishing.

[7] In order to improve the above mentioned problems, a firewood boiler is developed, which can control the supply of air during the combustion of wood;
however even though the supply of air is controlled, it is still hard to control the ignition, combustion and fire extinguishing depending on the kinds of wood, the thicknesses and sizes of the wood, the content of water of the wood, the preservation period of the pilot flame, and the tendency of a user.

[8] It is hard to determine a proper amount of oxygen which is needed to keep the pilot flame living for the sake of the following combustion after the fire is extinguished, so the pilot flame might be extinguished, which makes the re-combustion impossible. Unnecessary combustions might occur due to the oversupply of the oxygen, so overheating might occur or the fuel might be unnecessarily consumed.

[9] Since the heat energy generated as the wood is combusted is discharged to the outside by way of a stovepipe, the loss of energy increases, and the power of fire is not easy to control, so there are many problems in maintaining the temperature of the stored hot water in the boiler constant.
Disclosure of Invention

[10] Accordingly, the present invention is made to improve the problems encountered in the conventional art and it is an object of the present invention to provide a firewood boiler which can efficiently prevent the pilot flame from being extinguished and can efficiently prevent the overcombustion by controlling the amount of supply of oxygen.

[11] It is another object of the present invention to provide a firewood boiler which makes it possible to enhance a heat efficiency of an energy which is generated during the combustion of wood and which can be used over a long period of time, and the temperature of the stored hot water can be controlled.

[12] To achieve the above objects, there is provided a firewood boiler, comprising a boiler body including an input port for inputting a wood fuel and a combustion air; a smoke discharge port provided on the top while being connected with a stovepipe; an air input hole provided loser to the smoke discharge port; and a hot water storing part storing a hot water; a main opening and closing unit which is installed at the boiler body so as to open and close the input port and serves to selectively supply an external air into the interior of the boiler body or cutoff the supply of the external air in a state that the input port is closed; an auxiliary opening and closing unit supplying the external air into the interior of the boiler body when the input of the external air by way of the main opening and closing unit is cutoff; a temperature sensor detecting the temperature of the hot water; and a controller controlling the input and cutoff of the air supplied by way of the main opening and closing unit based on the temperature information detected by the temperature sensor, and the hot water storing part is integrally provided on the whole portions of the boiler body, and when the input of the external air by way of the main opening and closing unit is cutoff, the external air is supplied into the interior of the boiler body by way of the auxiliary opening and closing unit, thus maintaining the pilot flame of the wood fuel.

[13] According to an embodiment of the present invention, a firebox ceiling member is provided in the interior of the boiler body while dividing the inner space into an upper side and a lower side and crossing the interior, and the inner space of the boiler body is formed of a combustion chamber provided at a lower side of the firebox ceiling member and is configured to combust the wood fuel, and a connection passage provided at the upper side of the firebox ceiling member and connecting the combustion chamber and the smoke discharge port.

[14] According to an embodiment of the present invention, the firebox ceiling member is installed horizontally crossing the inner space of the boiler body and has the hot water storing part in the interior of the firebox ceiling member.

[15] According to an embodiment of the present invention, a concaved part is formed with a certain depth at the lower surface of the firebox ceiling member for the purpose of staying the heat of the combustion chamber therein, and the upper surface of the firebox ceiling member is gradually inclined in the upward direction toward the smoke discharge port.

[16] According to an embodiment of the present invention, there is further provided a cutoff member which is formed at a boundary between the connection passage and the smoke discharge port and is installed on the ceiling of the connection passage for thereby delaying the combustion heat which is discharged to the outside by way of the connection passage.

[17] According to an embodiment of the present invention, there is further provided a pressure adjusting member which is rotatably installed on the upper side of the boiler body so as to lower the pressure while being rotated by the pressure in the hot water storing part when the hot water stored in the hot water storing part is heated, and the pressure in the hot water storing part increases.

[18] According to an embodiment of the present invention, the main opening and closing unit comprises a main opening and closing door which is installed in the boiler body for opening and closing the input port and has an air injection port for injecting an external air into the input port; a blower which is installed in the interior of the main opening and closing door and is drive-controlled by the controller and serves to supply the external air into the inner space of the boiler body by way of the air injection port during the operation; a ventilation port opening and closing member which is engaged to the main opening and closing door while being movable between the closing position where the air injection port is closed and the opening position where the air injection port is opened; and an opening and closing motor which is driven in response to a control signal of the controller and serves to move the ventilation port opening and closing member between the opening position and the closing position.

[19] According to an embodiment of the present invention, the auxiliary opening and closing unit comprises an auxiliary opening and closing door which is installed at the boiler body for opening and closing the air input hole and in which a middle input port for receiving air and a middle discharge port for discharging the air are spaced apart from each other; an outer door which is engaged to the front side of the auxiliary opening and closing door and has an inner discharge port for introducing the air discharged by way of the middle discharge port into the interior of the boiler body.

[20] According to an embodiment of the present invention, the outer input port is disposed in the lower region of the outer door, and the middle input port is disposed in the lower region of the auxiliary opening and closing door, and the middle discharge port is disposed in the upper region of the auxiliary opening and closing door, and the inner discharge port is disposed in the lower region of the inner door, so the external air is introduced into the interior of the boiler body, and the combustion gas in the interior of the boiler body is not discharged to the outside of the boiler body.
Advantageous effects

[21] According to the firewood boiler according to the present invention, the amount of air can be controlled by means of a control of a main opening and closing unit and an auxiliary opening and closing unit while making sure that the pilot flame can be preserved and that overcombustion can be prevented.

[22] In particular, a small amount of air can be sucked by way of an auxiliary opening and closing unit with the aid of an internal pressure in a state that the main opening and closing unit is closed, so the pilot flame can be alive for a long period of time, and not extinguished.

[23] Since the pilot flame can be maintained, not extinguished, the combustion, fire extinguishing and ignition of the wood fuel are easy to control.
The disadvantage of the wood fuel can be improved, and the use of the wood fuel can be minimized, and the temperature of the stored hot water can be maintained constant. The management of the boiler is easy since the pilot flame can be maintained for a long period of time.

[24] In the conventional firewood boiler, though it is necessary to input wood fuel a few times per day for the sake of heating, the present invention has features in that the wood fuel can be inputted once per day, so the combustion can be selectively performed only when it is needed, and since the pilot flame can be maintained for a long period of time, the heated state can be maintained for one or more days even though the fuel is inputted once per day, so the maintenance is easy.

[25] Even though the stored water is heated and the internal pressure of the hot water storing part increases, the pressure adjusting member moves by the pressure and is opened, thus adjusting the pressure, so it is possible to , enhance the safety by preventing explosion.

[26]
Brief Description of Drawings

[27] Figure 1 is a perspective view illustrating an outer construction of a firewood boiler according to an embodiment of the present invention.

[28] Figures 2 and 3 are schematic cross-sectional views to explain a combustion stop state and a combustion state of a firewood boiler of Figure 1.

[29] Figures 4a to 4c are views illustrating a construction of a main opening and closing part of a firewood boiler according to the present invention.

[30] Figures 5a and 5b are views illustrating an operation state of a ventilation port opening and closing member of a main opening and closing part according to the present invention.

[31] Figures 6a to 6c are views illustrating a construction of an auxiliary opening and closing part of a firewood boiler according to the present invention.
Best modes for carrying out the invention

[32] The firewood according to the embodiments of the present invention will be described with reference to the accompanying drawings.

[33] Referring to Figures 1, 2 and 3, the firewood boiler 1 according to an embodiment of the present invention comprises a boiler body 10, a main opening and closing unit 20 installed at a lower region of the boiler body 10, an auxiliary opening and closing unit 30 installed at an upper region of the main opening and closing unit 20, a temperature sensor 40 detecting the temperature of the stored hot water in the boiler body 10 and a controller 50 controlling the opening and closing of the main opening and closing unit 20 depending on the temperature of the stored hot water.

[34] Here, the boiler body 10 comprises an inner space 11 for the purpose of generating heat energy by combusting the firewood in the interior.
On the front side of the boiler body 10 are provided, above and below, an input port 12 for inputting firewood and an air input hole 13. At the upper side of it is provided a smoke discharge port 14 connected with a stovepipe 70. The input port 12 is provided lower than the air input hole 13 and is larger than the air input hole 13.

[35] In addition, the boiler body 10 has a hot water storing part 15 for storing the hot water "W'. The hot water storing part 15 is integrally formed on the whole portions of the boiler body 10. The hot water stored in the hot water storing part 15 is heated by the combustion heat from the wood fuel combusted in the inner space 11 or can be supplied to a place where the heat is needed.
At this time, a heating pipe "A" can be provided in the hot water storing part 15.

[36] The hot water "W' in the hot water storing part 15 is not fully filled in the hot water storing part 15, namely, is filled with a certain marginal space 15a left. The marginal space 15a can be properly designed and determined. A ball top 19a is rotatable along the moving shaft 19b in the interior of the hot water storing part 15, thus detecting the level of the hot water "W'. An automatic water supply device 19c starts filling hot water in accordance with the water level detected by the ball top 19a. The automatic water supply device 19c is connected with a water supply line (not shown).

[37] An air input hole 13 is formed closer to the smoke discharge port 14.
The air input hole 13 is configured to supply a minimum amount of the external air by way of the auxiliary opening and closing unit 30 so that the pilot flame cannot be extinguished in the inner space 11 in a state that the input port 12 is fully closed.

[38] A pressure adjusting member 60 is installed at the top of the boiler body 10 so as to discharge the pressure of the hot water storing part 15 to the outside so as to prevent an explosion of the boiler body 10 when the hot water "W' of the hot water storing part 15 is heated, and the internal pressure increases. The pressure adjusting member 60 is rotatably installed at the pressure discharge port 16 formed at the top of the boiler body 10. It is preferred that when the generating pressure exceeds a certain level, the pressure adjusting member 60 is forcibly rotated by the pressure when a certain level of pressure generates, and the pressure is discharged to the outside.
When the pressure drops below a certain level, the pressure adjusting member 60 returns by means of its own weight, thus closing the pressure discharge port 16.

[39] Since the pressure adjusting member 60 is configured so that it can return by its own weight, the errors and operation defects do not occur even when it is exposed over a long period of time to vapor during its use. In other words, in the case that a safety value used at the pressure tank or the like is installed, since the hot water "W' is water, the vapor valve is exposed to the vapor during the use and is oxidized, so it becomes a cause of the errors. In that case, the pressure is not properly adjusted, which results in an increased chance of explosion. In contrast to that case, in the present invention, the installation of the pressure adjusting member 60 helps protect the boiler body in safe from the danger of explosion while preventing a high risk of accidents.

[40] The inner space 11 of the boiler body 10 is divided into a combustion chamber 11a of a lower side and a connection passage 11b of an upper side. A
firebox ceiling member 17 is installed in the interior of the boiler body 10 so as to divide the combustion chamber 11a and the connection passage 11b. The firebox ceiling member 17 is horizontally installed in the interior of the boiler body 10 so as to partition the inner space 11 into the upper and lower sides and has a hot water storing part 15. At the lower side of the firebox ceiling member 17 is provided a combustion chamber 11a so as to combust the wood fuel, and at the upper side of the firebox ceiling member 17 is provided a connection passage 11b connecting the combustion chamber 11a and the smoke discharge port 14.

[41] The firebox ceiling member 17 has a lower surface which is concaved in a certain depth, and in the combustion chamber 11a is provided a concave part 17a to allow the heat, namely, the heat energy generated during the combustion to gather. The upper surface of the firebox ceiling member 17 is a sloped surface 17b which is gradually inclined in the upward direction toward the smoke discharge port 14. The width of the connection passage 11b gradually decreases in the direction from the end portion of the firebox ceiling member 17 to the smoke discharge port 14. In addition, at the end portion of the connection passage 11b are provided the smoke discharge port 14 and the air input hole 13. Thanks to the formation of the slope surface 17b, the pyroligneous liquid generated in the combustion chamber 11a and moving along the connection passage 11b is forced to flow to the combustion chamber 11a along with soot for the sake of re-combustion. So, the efficiency of the fuel can be enhanced, and it is possible to prevent any inconvenience to the user which might occur since the pyroligneous liquid is discharged to the outside of the boiler.

[42] In addition, the production of the pyrol igneous liquid and soot can be minimized and the contamination in the interior of the stovepipe 70 can be prevented, so the maintenance cost and labor force needed to clean the inner side of the boiler body 10 and the stovepipe 70 can be saved, thus reducing the maintenance costs.

[43] A plurality of interfering rods "B" is provided in the interior of the concave part 17a so as to increase the staying time of the flame in the interior of the combustion chamber ha in such a way to delay the movement of the flame generating as fuel is combusted. As shown in Figure 3, the flame spreads over the interfering rods "B" as it is blocked by the interfering rods "B", so the staying time of the flame in the interior of the combustion chamber 11 a extends, whereby the heat transfer surface area to which heat is transferred increases, thus enhancing the returning ratio of the combustion heat.

[44] Most of the heat generated during the combustion in the combustion chamber ha stays in the concave part 17a of the lower side of the firebox ceiling member 17, thus fully heating the firebox ceiling member 17, and the cooled heat moves in the direction of the arrow of Figure 3 and is discharged to the discharge port 14 by way of the connection passage lib.

[45] At this time, the cut-off member 18 is installed at the boundary between the connection passage 11b and the smoke discharge port 14 so as to secondarily combust the combustion gas which was not firstly combusted as it stays in the connection passage 11b for a second. The cut-off member 18 is installed on the ceiling of the connection passage 11b, so the combustion gas and heat moving by way of the connection passage 11b can stay in a high temperature state while supplying oxygen to the combustion gas, thus burning the pyroligneous liquid with the aid of the second combustion, and so that the heat energy is discharged to the smoke discharge port 14 is delayed, thus enhancing the heat efficiency.

[46]

[47] Figures 4a to 4c are perspective, cross-sectional and schematic views illustrating the constructions of the main opening and closing unit 20 of the firewood boiler 1 according to the present invention.

[48] As shown therein, the main opening and closing unit 20 is installed at an outer side of the boiler body 10 in such a way to open and close the input port 12. The main opening and closing unit 20 is opened and closed in response to the control of the controller 50 and controls the supply of oxygen into the interior of the boiler body 10. The main opening and closing unit 20 comprises a main opening and closing door 21, an engaging plate 23 engaged to an inner side of the main opening and closing door 21, a ventilation port opening and closing member 24 for selectively opening and closing a second air injection port 22a, a blower 25 for supplying oxygen by way of the second air injection port 22a, and an opening and closing motor 27 driving the ventilation port opening and closing member 24.

[49] The main opening and closing door 21 is rotatably installed at an outer side of the boiler body 10 in such a way to selectively open and close the whole portions of the input port 12. The main opening and closing door 21 has a first air injection port 21a for injecting an external air into the input port 12, and a space in which are installed the blower 25, the ventilation port opening and closing member 24 and the opening and closing motor 27.

[50] The main opening and closing door 21 is installed in such a way to maintain the closed state of the input port 12 safely by means of a double-locking system (not shown). When the wood fuel is inputted into the combustion chamber 11a, the input port 12 is opened by rotating the main opening and closing door 21.

[51] At an outer surface of the main opening and closing door 21 there is provided a first air injection port 21a for injecting an external air, and at an inner surface of the main opening and closing door 21 there is provided a second air injection port 22a for injecting the air from the first air injection port 21a into the interior of the boiler body 10.

[52] The air introduced into the second air injection port 22a flows into the boiler body 10 by way of the air discharge port 23a disposed at the engaging plate 23 engaged to the inner side of the main opening and closing door 21.

[53] The blower 25 is installed in the interior of the main opening and closing door 21, and during the operation, the external air is supplied to the interior of the combustion chamber 11a by way of the air injection ports 21a, 22a and 23a. The blower 25 is configured to stop and start operating in response to a driving signal from the controller 50. As the blower 25 is driven, when external air is supplied to the combustion chamber 11a, the wood fuel in the combustion chamber 11a receives external air and maintains a combustion state, thus generating combustion energy. When the blower 25 stops, the second air injection port 22a is closed by the ventilation port opening and closing member 24, so the external air is not supplied. In this case, the wood fuel in the combustion chamber 11a is not combusted.

[54] At the main opening and closing door 21 there is installed the ventilation port opening and closing member 24 for the purpose of selectively opening and closing one of the air injection ports 21a, 22a and 23a disposed closer to the main opening and closing door 21, preferably, the air injection port 22a disposed in the middle of the air injection ports 21a, 22a and 23a.

[55] As shown in Figures 5a and 5b, the ventilation port opening and closing member 24 is rotatable by means of the opening and closing motor 27.
The ventilation port opening and closing member 24 is movably disposed between the closing position (the state of Figure 5b) where the second air injection port 22a is closed and the opening position (the state of Figure 5a) where the second air injection port 22a is opened.

[56] The opening and closing port 24a provided in position alignment with the second air injection port 22a passes through the surface of the ventilation port opening and closing member 24. The ventilation port opening and closing member 24 rotates to the opening position so that the opening and closing port 24a and the second air injection port 22a are aligned by means of the opening and closing motor 27 when the air is introduced into the interior of the boiler body 10. So, the air becomes communicated and it becomes movable.

[57] When the input of the air is cutoff, as shown in Figure 5b, the ventilation port opening and closing member 24 rotates to the closing position by means of the opening and closing motor 27, and the positions of the opening and closing port 24a and the second air injection port 22a become deviated, thus closing the ventilation port 22a. So, the input of the air into the interior of the boiler body 10 is cutoff.

[58] The opening and closing motor 27 is formed of a driving motor which drives the ventilation port opening and closing member 24 to move between the opening position and the closing position. The opening and closing motor 27 is configured to operate or stop in response to a control signal from the controller 50, so the second air injection port 22a can be opened or closed.

[59] When the ventilation port opening and closing member 24 is installed to slide, the opening and closing motor 27 might be a solenoid or a hydraulic cylinder unit, instead of the bidirectional driving motor. It is obvious that various driving devices might be adapted.

[60] A packing member 22 is provided in the engaging region of the main opening and closing door 21 and the engaging plate 23 for the sake of sealing.

[61]

[62] Figures 6a to 6c are perspective, disassembled and cross-sectional views illustrating a construction of the auxiliary opening and closing unit 30 according to the present invention.

[63] The auxiliary opening and closing unit 30 is configured to keep the pilot flame alive in such a way to supply a minimum amount of air into the interior of the boiler body 10 when the input of the air into the boiler body 10 is closed by means of the main opening and closing unit 20.

[64] The auxiliary opening and closing unit 30 comprises an auxiliary opening and closing door 31 installed in an opening and closing way at the input hole 13, an outer door 32 installed at an outer side of the auxiliary opening and closing door 31, and an inner door 34 installed at an inner side of the auxiliary opening and closing door 31.

[65] At both walls of the auxiliary opening and closing door 31 are provided a middle input port 31a for receiving air from the outer door 32, and a middle discharge part 33a for discharging the air introduced into the middle input port 31a.

[66] At the plate surface of the outer door 32 is provided an outer input port 32a for receiving external air, and at the plate surface of the inner door 34 is provided an inner output port 34a for discharging the air, which passed through the auxiliary opening and closing door 31, into the interior of the boiler body 10.

[67] Here, the outer input port 32a and the middle input port 31a are provided in the lower region of the auxiliary opening and closing door 31, and the middle discharge part 33a is provided in the upper region of the auxiliary opening and closing door 31, and the inner output port 34a is provided in the lower region.

[68] As indicated by the arrow, the air flow passage ranging from the outer side to the inner side is arranged, above and below, in a zigzag shape, so the external air can be naturally inputted by means of a suction pressure of the inner side of the boiler body 10; however the combustion gas in the boiler body is not discharged to the outside.

[69] As the auxiliary opening and closing unit 30 is installed, the input port 12 is closed by means of the main opening and closing unit 20. In a state that the supply of the external air by way of the input port 12 is disconnected, a minimum amount of the external air can be supplied to the combustion chamber 11a by way of the air input hole 13 and the connection passage 11b. In a state that the input port 12 is closed, the wood fuel is not combusted, and a minimum amount of external air is supplied by way of the air input hole 13, so the pilot flame of the wood fuel which is combusted in the combustion chamber 11a is not extinguished and can remain alive over a long period of time.

[70] The temperature sensor 40 is installed so as to detect the temperature of the hot water "W" stored in the hot water storing part 15 of the boiler body 10. The information detected by the temperature sensor 40 is transferred to the controller 50.

[71] The controller 50 controls the supply and the cutoff of the supply of the external air to the combustion chamber 11a by way of the main opening and closing unit 20. When the supply of the external air by way of the main opening and closing unit 20 is cutoff, a minimum amount of air can be supplied to the interior of the boiler body 10, namely, the combustion chamber 11a by way of the auxiliary opening and closing unit 30, so the pilot flame can survive over a long period of time in the extinguished state of the firewood in the combustion chamber 11a.

[72] When the temperature detected by the temperature sensor 40 lowers below the reference temperature, the controller 50 controls the opening and closing motor 27 so as to open the second injection hole 22a, and it is controlled that the external air can be inputted into the combustion chamber 11a by way of the input port 12 by driving the blower 25, so the power of fire of the wood fuel can be raised, and the wood fuel is combusted until the hot water "W' reaches the reference temperature.

[73] When the temperature detected by the temperature sensor 40 reaches the reference temperature, the controller 50 stops the operation of the blower 25 and closes the air input hole 13 by controlling the opening and closing motor 27, so the supply of the external air by way of the input port 12 is cutoff.

[74] At this time, the suction force is generated owing to the lack of oxygen in the interior of the combustion chamber 11a, and the oxygen introduced into the interior by way of the auxiliary opening and closing unit spreads toward the combustion chamber 11a. The combustion of the wood fuel in the combustion chamber 11a stops, and the heat energy is no longer generated. The pilot flame in the combustion chamber 11a can survive over a long period of time with the aid of a minimum amount of external air supplied by way of the auxiliary opening and closing unit 30. So, when a lot of external air is supplied by way of the input port 12 in the state of pilot flame, the combustion starts again. The combustion and extinguishing can be easily controlled even when using the wood fuel. It is possible to prevent an unnecessary consumption of the fuel.

[75]
Industrial Applicability

[76] According to the firewood according to the present invention, the amount of air can be controlled by controlling the main opening and closing unit and the auxiliary opening and closing unit, and the pilot flame can remain alive while making sure that there is not an over combustion.

[77] In particular, a minimum amount of external air can be sucked by way of the auxiliary opening and closing unit with the aid of the internal pressure in a state that the main opening and closing unit is closed, so the pilot flame can survive over a long period of time.

[78] Since the pilot flame can survive, the combustion, extinguishing and ignition of the wood fuel can be easily controlled. So, it is possible to keep constant the temperature of the hot water while overcoming the limited characteristics of the wood fuel and minimizing the use of the wood fuel.
Since the pilot flame can survive over a long period of time, the management of the boiler is easy, and the present invention is well applicable in the industry.

[79] [Descriptions of the reference numerals]

[80] 1: firewood boiler 10: boiler body

[81] 11a: combustion chamber 11b: connection passage

[82] 12: input port 13: air input hole

[83] 14: smoke discharge port 17: firebox ceiling member

[84] 17a: concaved part 17b: slope surface

[85] 18: cutoff member 19a: ball top

[86] 19b: moving shaft 19c: automatic water supply device

[87] 20: main opening and closing unit 21: main opening and closing door

[88] 21a: first air injection port 22: packing member

[89] 22a: second air injection port 23: engaging plate

[90] 23a: air discharge port 24: ventilation port opening and closing member

[91] 24a: opening and closing port 25: blower

[92] 27: opening and closing motor 30: auxiliary opening and closing unit

[93] 31: auxiliary opening and closing door 31a: middle input port

[94] 31b: middle discharge port 32: outer door

[95] 32a: outer input port 33: packing

[96] 34: inner door 34a: inner output port

[97] 40: temperature sensor 50: controller

[98] 60: pressure adjusting member 70: stovepipe

[99]

Claims

What is claimed is:

1. A firewood boiler, comprising:
a boiler body including:
an input port for inputting a wood fuel and a combustion air;
a smoke discharge port provided on top of the boiler body while being connected with a stovepipe;
an air input hole provided adjacent to the smoke discharge port;
and a hot water storing part storing hot water;
a main opening and closing unit which is installed at the boiler body so as to open and close the input port, the main opening and closing unit serving to selectively supply external air into the interior of the boiler body when the input port is open and serving to cut off the supply of the external air when the input port is closed;
an auxiliary opening and closing unit supplying the external air into the interior of the boiler body when the input of the external air by way of the main opening and closing unit is cut off;
a temperature sensor detecting the temperature of the hot water; and a controller controlling the input and cutoff of the air supplied by way of the main opening and closing unit based on the temperature information detected by the temperature sensor, wherein the hot water storing part is integrally provided on the boiler body, and when the input of the external air by way of the main opening and closing unit is cut off, the external air is supplied into the interior of the boiler body by way of the auxiliary opening and closing unit, thus maintaining the pilot flame of the wood fuel.

2. The boiler of claim 1, wherein a firebox ceiling member is provided in the interior of the boiler body while dividing an inner space of the boiler body into an upper side and a lower side and crossing the interior, wherein the inner space of the boiler body is formed of a combustion chamber provided at a lower side of the firebox ceiling member and is configured to combust the wood fuel, and wherein a connection passage is provided at the upper side of the firebox ceiling member, connecting the combustion chamber and the smoke discharge port.

3. The boiler of claim 2, wherein the firebox ceiling member is installed horizontally crossing the inner space of the boiler body and has the hot water storing part in the interior of the firebox ceiling member.

4. The boiler of claim 2, wherein a concave part is formed with a predetermined depth at the lower surface of the firebox ceiling member for the purpose of keeping the heat of the combustion chamber therein, and the upper surface of the firebox ceiling member is gradually inclined in the upward direction toward the smoke discharge port.

5. The boiler of claim 2, further comprising:
a cutoff member which is formed at a boundary between the connection passage and the smoke discharge port and is installed on a ceiling of the connection passage.

6. The boiler of claim 2, further comprising:
a pressure adjusting member which is forcibly rotated by pressure in the hot water storing part when a predetermined level of pressure generates, the pressure being discharged to the outside, and wherein, when the pressure drops below another predetermined level, the pressure adjusting member returns by means of its own weight, thus closing the pressure discharge port.

7. The boiler of any one of claims 1 to 6, wherein the main opening and closing unit comprises:

a main opening and closing door which is installed in the boiler body for opening and closing the input port and has an air injection port for injecting external air into the input port;
a blower which is installed in the interior of the main opening and closing door and is drive-controlled by the controller and serves to supply the external air into the inner space of the boiler body by way of the air injection port during the operation;
a ventilation port opening and closing member which is engaged to the main opening and closing door while being movable between a closed position where the air injection port is closed and an opened position where the air injection port is opened; and an opening and closing motor which is driven in response to a control signal of the controller and serves to move the ventilation port opening and closing member between the opened position and the closed position.
8. The boiler of any one of claims 1 to 6, wherein the auxiliary opening and closing unit comprises:
an auxiliary opening and closing door which is installed at the boiler body for opening and closing the air input hole and in which a middle input port for receiving air and a middle discharge port for discharging the air are spaced apart from each other;
an outer door which is engaged to the front side of the auxiliary opening and closing door and has an inner discharge port for introducing the air discharged by way of the middle discharge port into the interior of the boiler body.
9. The boiler of

claim 8, wherein an outer input port is disposed in a lower region of the outer door, and the middle input port is disposed in a lower region of the auxiliary opening and closing door, and the middle discharge port is disposed in an upper region of the auxiliary opening and closing door, and the inner discharge port is disposed in a lower region of the inner door, and the air flow passage ranging from the outer input port to the inner discharge port is arranged, above and below, in a zigzag shape, allowing the external air to be naturally inputted by means of a suction pressure of the inner side of the boiler body, without the combustion gas in the boiler body being discharged to the outside.