CN107726367A - A kind of biomass granule fuel heating-cooking dual-purpose stove - Google Patents

Abstract

A kind of biomass granule fuel heating-cooking dual-purpose stove proposed by the present invention, belongs to biomass combustion equipment technical field.Including hopper, the combustion chamber below hopper, the equipment box fixed and connected with combustion chamber rear end side wall, respectively positioned at the ash bucket and heat exchanger in combustion chamber inner bottom part center and front end, and blanking system, combustion system, supply air system and ignition system；Blanking system includes blanking dividing plate, blanking driving crank connecting link, blanking motor and the blanking travel switch being sequentially connected；Combustion system includes furnace grate support, fixed grate, the moving grate being sequentially connected, fire grate driving crank connecting link, fire grate motor and fire grate travel switch；Supply air system includes primary air fan, overfire air fan, secondary air channel and two Secondary Air chambers；Ignition system includes igniting blower fan, igniter and igniting airduct.The present invention can meet user heating and cooking demand simultaneously, and automaticity is high, and efficiency high, disposal of pollutants is low, easy to operate.

Description

A dual-purpose stove for heating and cooking with biomass pellet fuel

technical field

The invention relates to a dual-purpose stove for heating and cooking with biomass particle fuel, which belongs to the technical field of biomass burning equipment.

Background technique

my country is rich in biomass resources, and the theoretical total amount of available biomass resources is about 496 million tons of standard coal per year, which can fully meet the non-electric domestic energy consumption of 257 million tons of standard coal in rural areas. But at present, only about 8% of the biomass resources are utilized, and about 30% of the straw (about 100 million tce) is burned in the open air or discarded at random, resulting in serious energy waste and environmental pollution (Building Energy Conservation Research Center of Tsinghua University. China Annual Research Report on Building Energy Efficiency Development 2016. Beijing: China Architecture and Building Press, 2016). Burning biomass fuel through efficient and clean biomass stoves for heating and cooking is the correct way to rationally utilize biomass in rural areas. In the prior art, biomass cooking and heating stoves still have problems such as unreasonable structure and low degree of automation, specifically including: (1) a large part of stoves are separate heating stoves or cooking stoves, which cannot meet the needs of cooking and heating at the same time; (2) The feeding of the furnace is passive feeding without a transmission mechanism, and the feeding speed and amount of feeding cannot be controlled; (3) The grate is mainly a fixed grate, the contact space between fuel and air is small, and the combustion is not sufficient; (4) ) The primary air and secondary air of a large part of the stove adopt natural ventilation, and it is difficult to quantitatively control the air distribution; (5) manual ignition is required for ignition, and the ignition process is cumbersome; (6) the heat exchange area of the heat exchanger is The flue gas flow remains unchanged, and the volume change caused by the flue gas temperature change is not considered, resulting in low heat exchange efficiency of the furnace. Therefore, the development of biomass stoves suitable for use in rural areas that can meet both heating and cooking needs plays an important role in realizing the large-scale and clean utilization of biomass resources.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art and provide a dual-purpose biomass pellet fuel heating and cooking stove, which aims to solve the problems of energy waste and environmental pollution caused by irrational use of biomass resources in rural areas and Meeting heating and cooking energy needs in rural areas.

Technical scheme of the present invention is as follows:

A dual-purpose biomass pellet fuel heating and cooking stove, characterized in that it includes a material box (2), a combustion chamber (37) located below the material box (2), fixed and communicated with the rear end side wall of the combustion chamber (37) The equipment box (29), the ash hopper (21) located in the center of the bottom of the combustion chamber (37) and the heat exchanger fixed to the front side wall of the combustion chamber and connected to the top, as well as the feeding system, combustion system, air supply system and ignition system; where,

The blanking system includes a blanking partition (3) in contact with the top of the combustion chamber (37) and the bottom of the material box (2), and the blanking drive crank connected to the blanking partition (3) in sequence Rod (32) and the blanking driving motor (30) that is fixed on the outside of the equipment box (29) sidewall, and the blanking travel switch (28) that is fixed on the rear end sidewall of the equipment box (29);

Described combustion system comprises the fire grate support (22) that is positioned at combustion chamber (37), is all positioned at the fixed fire grate (18) of ash hopper (21) top and movable fire grate (19), and this movable fire grate (19) ) rear end connected successively to the grate drive crank connecting rod (23) and the grate drive motor (24) fixed outside the side wall of the equipment box (29), and the furnace Row travel switch (25); the upper surface of the fixed grate (18) is in contact with the lower surface of the extended vertical plate fixed on the front end of the movable grate (19), and the rear end of the fixed grate (18) is supported by the grate bracket (22) On the side wall of the combustion chamber (37); the ash door (16) is fixed on the upper surface of the front end of the fixed grate (18); in the combustion chamber (37), the movable grate (19) and the fixed grate ( 18) A hearth (17) is arranged above; a cooking burner (36) is arranged on the top of the combustion chamber (37) above the grate;

The air supply system is located in the middle of the combustion system and the blanking system, and includes a primary air blower (26) whose air outlet is located inside the equipment box (29), a secondary air blower (31) whose air outlet is located inside the combustion chamber (37), respectively The first secondary air chamber (8) and the second secondary air chamber (8a) fixed on the two side walls of the furnace, and the two ends are respectively connected with the air outlet of the secondary fan (31) and the first secondary air chamber (8) A connected secondary air pipe (4); secondary air holes are distributed on the side walls of the two secondary air chambers close to the fixed fire grate (18);

The ignition system is located in the middle of the air supply system and the combustion system, including an ignition fan (27) whose air outlet is located in the combustion chamber (37), fixed on the lower surface of the first secondary air chamber (8) and a movable fire grate (19) The igniter (20) between the upper surfaces, and the ignition air pipe (5) connecting the ignition fan (27) and the igniter (20).

The heat exchanger includes a water-cooled wall (10) and a flue (11), the space in the heat exchanger except the flue (11) is a connected water-cooled wall (10), the upper and lower sides of the water-cooled wall (10) The lower side is respectively provided with a water outlet pipe (33) and a water inlet pipe (34); the flue (11) is three rows of vertical pipes with gradually decreasing cross-sectional areas arranged along the moving direction of the movable grate.

This dual-purpose furnace also comprises the dust removal system that is positioned at the front end of combustion chamber (37); This dust removal system comprises the cyclone dust collector (15), the bag filter (14) and the smoke exhaust blower ( 13), the inlet of the cyclone dust collector (15) is connected with the vertical flue outlet at the inner rear end of the heat exchanger through the exhaust pipe (12).

Described equipment box (29) is provided with the comprehensive control board that integrates editable logic controller, power transmission controller and power supply controller in one, and this comprehensive control board is respectively connected with each travel switch, drive motor, blower fan and igniter power supply. connect.

The invention has the following advantages and outstanding effects: ① By arranging the heat exchanger and the cooking crater, it can meet the needs of users for heating and cooking at the same time; Combustion stability is improved, the fuel combustion rate is improved, and pollutant emissions are reduced; ③The heat exchange between the heat exchanger with the flue heat exchange area and water is improved, and the convective heat exchange capacity is improved, and the heat exchange intensity is enhanced; ④Through the program The action of the driving motor is controlled to realize automatic operation and liberate the labor force; ⑤ the present invention has a simple structure and is easy to use.

Description of drawings

Fig. 1 is a top view of a biomass pellet fuel heating and cooking stove provided by the present invention.

FIG. 2 is a cross-sectional view along line A-A of FIG. 1 .

Fig. 3 is a B-B sectional view of Fig. 2 .

FIG. 4 is a C-C sectional view of FIG. 2 .

FIG. 5 is a D-D sectional view of FIG. 2 .

The parts in the figure represent: 1-Material box cover; 2-Material box; 3-Blanking partition; 4-Secondary air duct; 5-Ignition air duct; 6-Baffle; 7-First and secondary air hole ; 7a-the second secondary air hole; 8-the first secondary air chamber; 8a-the second secondary air chamber; 9-the inner wall of the rear furnace; 9a-the inner wall of the front furnace; 12-exhaust pipe; 13-exhaust fan; 14-bag dust collector; 15-cyclone dust collector; 16-ash door; 17-furnace; 18-fixed grate; Igniter; 21-ash hopper; 22-grate bracket; 23-grate drive crank connecting rod; 24-grate drive motor; 25-grate travel switch; 26-primary fan; 27-ignition fan; 28-down Material stroke switch; 29-equipment box; 30-feeding drive motor; 31-secondary fan; 32-feeding drive crank connecting rod; 33-water outlet pipe; 34-water inlet pipe; 35-cooking burner cover; 36-cooking Burner, 37-combustion chamber.

detailed description

The working principle and specific structure of the present invention will be further described below in conjunction with the accompanying drawings.

Fig. 1 is a top view of a biomass pellet fuel heating and cooking stove provided by the present invention, Fig. 2 is a sectional view of A-A of Fig. 1 , Fig. 3 is a sectional view of B-B of Fig. 2 , and Fig. 2 is a sectional view of C-C of Fig. 1 , Fig. 5 is a D-D sectional view of Fig. 2 .

The biomass pellet fuel heating and cooking stove of the present invention includes a material box 2, a combustion chamber 37 located below the material box 2, and an equipment box 29 fixed and communicated with the rear end side wall of the combustion chamber 37, located at the bottom of the combustion chamber 37 The central ash hopper 21 and the heat exchanger fixed to the front side wall of the combustion chamber and communicated above, as well as the feeding system, combustion system, air supply system and ignition system; wherein,

The blanking system includes a blanking partition 3 that is in contact with the bottom of the combustion chamber 37 top and the bottom of the feed box 2 (the upper opening of the feed box is covered with a feed box cover 1), and the blanking drive that is connected with the blanking partition 3 in sequence Crank connecting rod 32 and the blanking drive motor 30 that is fixed on the outside of equipment box 29 side walls, and the blanking travel switch 28 that is fixed on equipment box 29 rear end side walls; The blanking stroke switch 28 contacts; the front end of the blanking partition 3 is provided with a heat-insulating cement block 4, which is used to prevent the temperature at the bottom of the blanking partition 3 and the material box 2 from being too high; the blanking drive motor 30 is connected to the blanking drive crank connecting rod 32 drives the blanking partition 3 to reach the front end under multiple actions to realize a small amount of multiple feeding of granular fuel;

The combustion system includes a grate bracket 22 located in the combustion chamber 37, a fixed grate 18 and a movable grate 19 both located on the upper part of the ash hopper 21, and a grate drive crank connecting rod sequentially connected to the rear end of the movable grate 19 23 and the grate drive motor 24 that is fixed on the outside of the equipment box 29 side walls, and the grate travel switch 25 that is fixed on the side wall of the rear end of the equipment box 29, when the grate drive crank connecting rod 23 is positioned at the rear end The upper surface of the fixed grate 18 is in contact with the lower surface of the extended vertical plate fixed on the front end of the movable grate 19, and the rear end of the fixed grate 18 is supported on the side wall of the combustion chamber 37 through the grate bracket 22; The upper surface of the front end of the fire grate 18 is fixed with an ash door 16, and the upper layer of fuel stays on the fixed fire grate 18 under the obstruction of the inner wall 9a of the front furnace, and the lower layer of ashes falls from the ash door 16 into the ash hopper 21; In the chamber (37), a furnace (17) is arranged above the movable grate (19) and the fixed grate (18); the top of the combustion chamber 37 above the movable grate 19 and the fixed grate 18 is provided with a cooking burner 36; The movable grate 19 and the fixed grate 18 of the embodiment are all arranged with a plurality of grate ventilating grooves, the width of each grate ventilating groove is 5mm, and the number of ventilating grooves located at the front end on the movable grate 19 is more than that at the rear end The movable fire grate 19 of the present embodiment realizes reciprocating motion under the drive of the fire grate drive motor 24 and the drive of the fire grate drive crank connecting rod 23, and the fuel on the movable fire grate 19 is gradually pushed forward under the resistance of the rear side furnace inner wall 9 , until it falls to the fixed grate 18, the vertical plate extending on the front side of the movable grate 19 pushes the fuel on the fixed grate 18 to move forward continuously during the movement of the movable grate 19, and the ash after the fuel is burned is pushed into the ash hopper 21 ;

The air supply system is located in the middle of the combustion system and the blanking system, and includes a primary fan 26 whose air outlet is located inside the equipment box 29, a secondary fan 31 whose air outlet is located inside the combustion chamber 37, and a second fan respectively fixed on the two side walls of the furnace. The primary and secondary air chamber 8 and the second secondary air chamber 8a, and the secondary air pipe 4 that both ends communicate with the secondary fan 31 air outlet and the first secondary air chamber 8 respectively; the first and second secondary air The first secondary air hole 7 and the second secondary air hole 7a are respectively distributed on the side wall of the cavity close to the fixed fire grate 18; the primary fan 26 of this embodiment is fixed on the rear end side wall of the equipment box 29, and the primary air first Send into equipment box 29 and be used for cooling blanking drive motor 30 and grate drive motor 24, then send to fuel layer; The first and second secondary air holes of the present embodiment are all round holes with a diameter of 6mm in a row, And the direction of the air outlet of the secondary air hole is obliquely downward toward the middle part of the furnace 17, and the top of the first secondary air chamber 8 is arranged as an oblique cross-section to facilitate blanking; The front side is also provided with a baffle plate 6, leaving a 20mm gap between the bottom of the baffle plate 6 and the sidewall of the first secondary air chamber 8, the baffle plate 6 blocks the flame from extending to the material box 2 on the one hand, and can Prevent feeding too much and too fast at a time.

The ignition system is located in the middle of the air supply system and the combustion system, and is located 30-50 mm above the combustion system, including an ignition fan 27 whose air outlet is located in the combustion chamber 37, fixed on the lower surface of the first secondary air chamber 8 and the movable furnace The igniter 20 between row 19 upper surfaces and the ignition air duct 5 connecting said ignition blower 27 and igniter 20; The hot air through the high-temperature igniter 20 is blown to the fuel layer of the grate until the fuel is ignited; the igniter 20 of this embodiment is made of silicon nitride high-temperature ceramics, which has stable heat generation and long service life. Start and stop.

The heat exchanger is connected to the front side wall of the combustion chamber 37 near the ash door 16 and communicates upwards, including a water-cooled wall 10 and a flue 11. The space in the heat exchanger except the flue 11 is a connected water-cooled wall 10 , the upper and lower sides of the water-cooled wall 10 are respectively provided with a water outlet pipe 33 and a water inlet pipe 34; the flue 11 is three rows of vertical pipes whose cross-sectional area gradually decreases along the direction parallel to the movement of the movable grate 19, that is, according to The flue gas flows through three return journeys arranged in sequence; in this embodiment, a row of vertical pipes located at the rear end includes a plurality of square smoke pipes, and the direction of the flue gas is the descending direction, corresponding to the first return journey; a row of vertical pipes located in the middle includes multiple square pipes. Two alternately arranged square smoke pipes and circular smoke pipes, the direction of the flue gas is the upward direction, corresponding to the second return journey; a row of vertical pipes at the front end includes a plurality of circular smoke pipes, the direction of the smoke gas is the downward direction, corresponding to the third return journey return; and the side length of the square smoke pipe and the cross-sectional diameter of the circular smoke pipe are both 50mm.

The cooking crater 36 is located on the upper surface of the combustion chamber 37 corresponding to the front end of the movable grate 19. A detachable cooking crater cover 35 is arranged above the cooking crater 36. The lower surface of the cooking crater cover 35 is covered with an aluminum silicate fiber thermal insulation board .

The dual-purpose furnace of the present invention also includes a dust removal system positioned outside the front end of the combustion chamber 37; The inlet of the filter is connected to the vertical flue outlet at the rear end of the heat exchanger through the exhaust pipe 12; the filter material in the bag filter 14 of this embodiment adopts high-temperature-resistant polyester filter material.

Described equipment box 29 is provided with the comprehensive control board that integrates editable logic controller (PLC), power transmission controller and power supply controller in one, and this comprehensive control board is connected with each travel switch, drive motor, blower fan and igniter respectively Electric connection, used to automatically control the normal and stable operation of the burner; wherein, the blanking stroke switch 28 is in the normally open state, and the closing time of the blanking stroke switch 28 is controlled by the integrated control board to determine the initial forward time of the blanking partition 3 , The grate stroke switch 25 is similar to the blanking stroke switch. All the controllers in the integrated control board of this embodiment adopt conventional chips.

Each component part of the present invention is conventional product.

Principle of the present invention and working process are as follows:

Add the biomass particle fuel into the material box 2, cover the material box cover 1, and the blanking drive motor 30 drives the blanking drive crank connecting rod 32 to drive the blanking partition 3 and then withdraws to the blanking drive crank connecting rod 32 and the blanking drive. Stroke switch 28 is contacted, and blanking stroke switch 28 is closed, and blanking drive motor 30 stops working, and granular fuel falls to the gap in front of blanking partition 3 through hopper 2 and blanking partition 3, and blanking stroke switch 28 is on. Under the control of the integrated control board, the blanking drive motor 30 drives the blanking partition 3 to move forward, pushing the fuel to drop on the movable grate 19 in stages; the igniter 20 is turned on, and the ignition fan 27 will generate heat from the igniter 20 Blow to the fuel area of the movable grate 19, close the igniter 20 to complete the ignition after the fuel is on fire; the grate drive motor 24 drives the grate drive crank connecting rod 23 to drive the movable grate 19 to reciprocate, and the fuel is blocked by the inner wall 9 of the rear furnace Gradually push down to the front end of the movable grate 19, then drop to the fixed grate 18 to continue burning, the vertical plate extended at the front of the movable grate 19 continuously pushes the fuel on the fixed grate 18 forward, and finally the ash falls through the ash door 16 In the ash hopper 21, the action of the grate travel switch 25 is similar to that of the blanking travel switch 28; the primary air is sent into the equipment box 29 through the primary fan 26, and then sent to the fuel area through the combustion chamber 37 communicated with the equipment box 29; The wind is sent into the secondary air cavity by the secondary fan 31 through the secondary air pipe 4, and then enters the upper part of the furnace 17 from the secondary air hole to burn with the combustible components in the flue gas; the fully burned flue gas enters the flue gas from the upper part of the furnace 17. 11, the heating circulating water enters the water-cooled wall 10 from the water inlet pipe 34, and flows out from the outlet pipe 33 after exchanging heat with the flue gas in the flue 11. The temperature of the flue gas in the flue 11 gradually decreases, and the area of the three-row flue 11 gradually Reduced to adapt to the volume reduction characteristics brought about by the reduction of flue gas temperature, ensuring the flue gas flow rate and enhancing heat transfer; the low-temperature flue gas after heat exchange flows out from the outlet of flue 11 into the exhaust pipe 12, and then passes through the cyclone dust collector 15 Filter the large particles in the flue gas, and then filter the fine particles through the bag filter 14, and then discharge them through the smoke exhaust fan 13; state, then close the blanking drive motor 30, and when the movable grate 19 reciprocates several times to make the fuel on the movable grate 19 and the fixed grate 18 burn out, turn off the grate drive motor 24, and close the primary fan 26 and the secondary fan 37. Turn off the smoke exhaust fan 13 after the smoke is exhausted, and finally pull out the ash hopper 21 to pour out the ash, then put the ash hopper 21 into the bottom of the combustion chamber and press it tightly.

Claims (10)

1. A biomass particle fuel heating and cooking dual-purpose furnace is characterized by comprising a material box (2), a combustion chamber (37) positioned below the material box (2), an equipment box (29) fixed and communicated with the side wall of the rear end of the combustion chamber (37), an ash hopper (21) positioned in the center of the bottom in the combustion chamber (37), a heat exchanger fixed and communicated with the side wall of the front end in the combustion chamber, a blanking system, a combustion system, an air supply system and an ignition system; wherein,

the blanking system comprises a blanking partition plate (3) which is contacted with the top of the combustion chamber (37) and the bottom of the material box (2), a blanking driving crank connecting rod (32) which is sequentially connected with the blanking partition plate (3), a blanking driving motor (30) which is fixed outside the side wall of the equipment box (29), and a blanking travel switch (28) which is fixed on the side wall of the rear end of the equipment box (29);

the combustion system comprises a grate support (22) positioned in a combustion chamber (37), a fixed grate (18) and a movable grate (19) which are positioned at the upper part of an ash bucket (21), a grate driving crank connecting rod (23) which is sequentially connected with the rear end of the movable grate (19), a grate driving motor (24) which is fixed outside the side wall of an equipment box (29), and a grate stroke switch (25) which is fixed on the side wall of the rear end of the equipment box (29); the upper surface of the fixed grate (18) is contacted with the lower surface of an extending vertical plate fixed at the front end of the movable grate (19), and the rear end of the fixed grate (18) is supported on the side wall of the combustion chamber (37) through a grate support (22); an ash falling door (16) is fixed on the upper surface of the front end of the fixed grate (18); a hearth (17) is arranged above the movable grate (19) and the fixed grate (18) in the combustion chamber (37); a cooking fire hole (36) is arranged at the top of the combustion chamber (37) positioned above the fire grate;

the air supply system is positioned in the middle of the combustion system and the blanking system and comprises a primary air fan (26) with an air outlet positioned in the equipment box (29), a secondary air fan (31) with an air outlet positioned in the combustion chamber (37), a first secondary air cavity (8) and a second secondary air cavity (8a) which are respectively fixed on two side walls of the hearth, and a secondary air pipe (4) with two ends respectively communicated with the air outlet of the secondary air fan (31) and the first secondary air cavity (8); secondary air holes are distributed on the side walls of the two secondary air cavities close to the fixed grate (18);

the ignition system is arranged in the middle of the air supply system and the combustion system and comprises an ignition fan (27) with an air outlet positioned in a combustion chamber (37), an igniter (20) fixed between the lower surface of a first secondary air cavity (8) and the upper surface of a movable grate (19) and an ignition air pipe (5) connected with the ignition fan (27) and the igniter (20).

2. The biomass particle fuel heating and cooking dual-purpose furnace according to claim 1, characterized in that: the heat exchanger comprises a water-cooled wall (10) and a flue (11), the space in the heat exchanger except the flue (11) is the communicated water-cooled wall (10), and the upper side and the lower side of the water-cooled wall (10) are respectively provided with a water outlet pipe (33) and a water inlet pipe (34); the flue (11) is three rows of vertical pipelines with gradually reduced cross-sectional areas, which are distributed along the moving direction parallel to the moving grate.

3. The biomass particle fuel heating and cooking dual-purpose furnace according to claim 1, characterized in that: cooking fire hole (36) are located combustion chamber (37) upper surface that movable grate (19) front end corresponds, and this cooking fire hole (36) top sets up the cooking fire hole lid (35) that can open, and cooking fire hole lid (35) lower surface covers there is thermal-insulated heated board.

4. The biomass particle fuel heating and cooking dual-purpose furnace according to claim 1, characterized in that: the front end of the blanking partition plate (3) is provided with a heat insulation cement block (4) for preventing the bottom of the blanking partition plate (3) and the bottom of the feed box (2) from being overhigh in temperature.

5. The biomass particle fuel heating and cooking dual-purpose furnace according to claim 1, characterized in that: the primary air fan (26) is arranged on the side wall of the rear end of the equipment box (29).

6. The biomass particle fuel heating and cooking dual-purpose furnace according to claim 1, characterized in that: the direction of an air outlet of the secondary air hole is inclined downwards to the middle part of the hearth (17); the top of the first secondary air cavity (8) is provided with an oblique section convenient for blanking.

7. The biomass particle fuel heating and cooking dual-purpose furnace according to claim 1, characterized in that: a plurality of grate ventilation grooves are uniformly distributed on the movable grate (19) and the fixed grate (18), and the number of the ventilation grooves on the movable grate (19) at the front end is more than that of the ventilation grooves at the rear end.

8. The biomass particle fuel heating and cooking dual-purpose furnace according to claim 1, characterized in that: the top still is equipped with baffle (6) in combustion chamber (37) and is located unloading baffle (3) front side department, leaves 20mm space between this baffle (6) bottom and first overgrate air chamber (8) lateral wall.

9. The biomass particle fuel heating and cooking dual-purpose furnace according to claim 2, characterized in that: the dual-purpose furnace also comprises a dust removal system positioned outside the front end of the combustion chamber (37); the dust removal system comprises a cyclone dust collector (15), a bag-type dust collector (14) and a smoke exhaust fan (13) which are sequentially connected through a smoke exhaust pipe (12), wherein the inlet of the cyclone dust collector (15) is connected with the vertical flue outlet at the rear end in the heat exchanger through the smoke exhaust pipe (12).

10. The biomass particle fuel heating and cooking dual-purpose furnace according to claim 9, characterized in that: the equipment box (29) is internally provided with a comprehensive control panel integrating an editable logic controller, a power transmission controller and a power controller, and the comprehensive control panel is electrically connected with each stroke switch, the driving motor, the fan and the igniter respectively.