Downdraft biomass gasifier

Abstract

The invention relates to the technical field of biomass gasification furnaces, and discloses a downdraft biomass gasification furnace which comprises a support and a gasification furnace sensor, a fire grate segment set is arranged at the top of the support and comprises an upper fire grate segment, a middle fire grate segment and a lower fire grate segment, and the upper fire grate segment, the middle fire grate segment and the lower fire grate segment are arranged on the support. The upper fire grate segment, the middle fire grate segment and the lower fire grate segment each comprise a plurality of fixed fire grate segments and a plurality of movable fire grate segments, and the fixed fire grate segments and the movable fire grate segments are alternately arranged. According to the invention, the plurality of hydraulic rods are used for detecting the reaction intensity of each section according to the gasification furnace sensor to control the material pushing frequency of different sections in the gasification furnace in a segmented manner, and the arrangement number of the upper fire grate segment, the middle fire grate segment and the lower fire grate segment corresponding to the ventilation holes in the single fire grate segment is reduced; the staying time of the material layer in different sections is matched with the reaction intensity, and the water tank synchronously adjusts the cooling rate and the gas inlet amount of the gasifying agent during adjustment in cooperation with the adjusting mechanism, so that the gas conveying quality of the gasification furnace is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of biomass gasifiers, in particular to a downdraft biomass gasifier. Background Art

[0002] Downdraft gasifier is a kind of equipment that converts solid fuel into combustible gas through gasification. In the process of solid fuel gasification, the biomass fuel will be cracked under the condition of incomplete combustion, and the organic hydrocarbon chains with higher molecular weight will be transformed into combustible gases such as CO, H2, CH4 with lower molecular weight. The air of the downdraft gasifier enters from the top, passes through the drying layer, pyrolysis layer, oxidation layer and reduction layer in turn, and the gas as the gasifier enters from the bottom of the reciprocating grate, and the gasifier gas enters into the furnace through the gaps between the grate pieces and the round holes on the grate pieces.

[0003] The reciprocating grate of a downdraft gasifier is usually composed of a fixed grate and a movable grate, which are used to support the fuel layer and drive the fuel layer to move. One end of the fixed grate piece is set on the fixed crossbeam, and one end of the movable grate piece is sleeved on the movable crossbeam. The fixed grate pieces and the movable grate pieces are alternately placed in the direction of fuel movement to form a stepped arrangement and have a certain inclination angle. The side of the reciprocating grate forms a ripple shape with peaks and valleys. When working, the movable grate pieces of the reciprocating grate reciprocate in the inclined direction, driving the fuel forward, so that the fuel passes through the furnace distillation zone, high-temperature combustion zone and ash secondary combustion zone in turn and then falls into the slag pit. The biomass raw materials in the gasifier always need to maintain a certain height in the furnace to prevent the gasifier gas from taking a short distance, resulting in the gasifier flowing out without reacting with the biomass, reducing the gasification quality, and the generated gas cannot even be burned.

[0004] However, during the use of traditional downdraft gasifiers, the movable grates located in different areas of the gasifier have the same movement frequency, the number of ventilation holes on the grate is the same, and the reaction rates of biomass fuel in the front and rear areas of the grate are different. In the intense reaction section, the feeding is fast and the slag is discharged quickly, causing some biomass to be discharged from the gasifier before being burned, resulting in a lower gasification rate. In addition, due to the large thickness of the biomass raw materials, the amount of ash and slag in the biomass gasifier and the time the ash and slag remain in the furnace are large, causing the ash and slag in the gasifier to be easily coked, and the feeding amount in the ignition process is large and the ignition time is long. Summary of the invention

[0005] In view of the shortcomings of the existing downdraft gasifiers mentioned in the background technology during use, the present invention provides a downdraft biomass gasifier, which has the advantages of segmented control of the wheel frequency, controlling the grate and ash cooling rate according to the grate frequency, and controlling the grate ventilation rate, thereby solving the technical problems raised in the above background technology.

[0006] The present invention provides the following technical solutions: a downdraft biomass gasifier, comprising a bracket and a gasifier sensor, a grate plate group is arranged on the top of the bracket, the grate plate group comprises an upper grate plate, a middle grate plate and a lower grate plate, the upper grate plate, the middle grate plate and the lower grate plate each comprise a plurality of fixed grate plates and movable grate plates, the plurality of fixed grate plates and movable grate plates are arranged alternately, the fixed grate plates and the movable grate plates are arranged obliquely and overlap each other end to end to form a stepped arrangement, the upper grate plate, the middle grate plate and the lower grate plate are arranged in sequence in the grate step pushing direction;

[0007] The gasifier sensor is arranged in the gasifier to detect the intensity of the gasification reaction in the furnace corresponding to different sections of the reciprocating grate. An adjustment mechanism is arranged at the bottom of the bracket. The adjustment mechanism can drive the upper grate, the middle grate and the lower grate to move at different frequencies according to the intensity of the reaction in each section detected by the gasifier sensor, and adjust the pushing frequency in sections. The adjustment mechanism can adjust the air intake and heat dissipation of each section of the upper grate, the middle grate and the lower grate according to the changing trend of the amount of biomass material after adjustment at different frequencies. When the amount of biomass material in the corresponding section increases, the air intake and heat dissipation of different grate sections are increased successively as the reciprocating pushing is carried out. When the amount of biomass material in the corresponding section decreases, the air intake and heat dissipation of different grate sections are reduced successively.

[0008] Preferably, one side of the bottom end of the upper grate sheet, the middle grate sheet and the lower grate sheet is sleeved with a grate crossbeam, the adjustment mechanism includes a push plate, the bracket is slidably connected to the push plate, the number of the push plates is set to be several, one side of the bracket is fixedly provided with several hydraulic push rods corresponding to the number of the push plates, and connecting push rods are provided between the several hydraulic push rods and the corresponding push plates, and the connecting push rods are composed of two connecting rods hinged;

[0009] Several of the hydraulic push rods can extend and retract at different frequencies to cooperate with the push plate, grate beam and connecting push rod, driving the corresponding movable grate slices among the upper grate slices, middle grate slices and lower grate slices to move at different rated frequencies. Several of the connecting push rods are respectively an upper push rod, a middle push rod and a lower push rod. One end of the connecting push rod is fixedly connected to the hydraulic push rod, and the other end of the connecting push rod is hinged to the corresponding push plate.

[0010] Preferably, the top surfaces of the upper grate slices, the middle grate slices and the lower grate slices are all provided with a plurality of through ventilation holes, and the plurality of ventilation holes on a single grate slice are evenly arranged, and the number of ventilation holes arranged on a single grate slice corresponding to the upper grate slices, the middle grate slices and the lower grate slices decreases successively, so that the number of ventilation holes corresponding to the thin layer of biomass raw materials on the grate is small, and the number of ventilation holes corresponding to the thick layer of biomass raw materials on the grate is large.

[0011] Preferably, a water tank for cooling the ash layer and the grate is fixedly provided on the top of the bracket, the number of the water tanks is set to two and they are symmetrically arranged on both sides of the grate plate group, one side of the water tank is fixedly connected to a water inlet pipe, and the other side of the water tank is fixedly connected to a water outlet pipe, and the water tank is connected to the cooling mechanism through the water inlet pipe and the water outlet pipe.

[0012] Preferably, ignition holes for the heating rod to pass through are provided on both sides of the water tank.

[0013] Preferably, a sliding groove is provided on one side of the water tank, the number of the sliding grooves is set to two and the two sliding grooves correspond to the middle grate plate and the lower grate plate respectively, and the adjustment mechanism further comprises a sliding plate, the sliding plate is slidably arranged in the sliding groove, and a fixed block is fixedly connected to one side of the sliding groove;

[0014] A screw is rotatably sleeved at the midpoint of the fixed block, a connecting groove is provided on one side of the sliding plate, a heat dissipation groove is provided on one side of the water tank, the number of the connecting grooves is set to be several, an adjusting rod is slidably clamped in the connecting groove, and one end of the adjusting rod is connected to a heat conducting rod.

[0015] Preferably, one end of the screw is fixedly connected to a No. 1 sprocket, the bottom of the bracket is rotatably connected to a support shaft via a rotating shaft, the number of the support shafts is set to two, one end of the support shaft body is fixedly sleeved with a transmission gear, the bottoms of the middle push rod and the lower push rod are both fixedly connected to a toothed plate adapted to the transmission gear, the toothed plate meshes with the transmission gear, both sides of the bottom of the bracket are rotatably connected to the transmission shaft via a rotating shaft, and the bottom of the bracket is rotatably connected to a connecting shaft via a rotating shaft;

[0016] The transmission shaft is connected to the support shaft through a clutch, one side of the transmission shaft is fixedly connected to a one-way transmission mechanism, both sides of the connecting shaft are fixedly connected to connecting gears, the one-way transmission mechanism drives the connecting gear to rotate in one direction, and the transmission directions of the one-way transmission mechanisms on both sides of the bracket are opposite, both ends of the connecting shaft are fixedly connected to a second sprocket that cooperates with the first sprocket, and the second sprocket is connected to the first sprocket through a chain transmission.

[0017] Preferably, the one-way transmission mechanism includes a ratchet and an external gear, the external gear is rotatably connected to the bracket via a rotating shaft, the ratchet is fixedly connected to the corresponding transmission shaft, the inner side of the external gear is rotatably connected to a stopping claw, one end of the stopping claw is fixedly connected to a spring, and the connecting gear is meshed with the external gear.

[0018] Preferably, the tops of the lower grate plate and the middle grate plate are both provided with through ventilation slots, the heat conducting rods are used to conduct heat and close the ventilation slots, the tops of the heat conducting rods are provided with through adjustment slots, and the adjustment slots partially correspond to the ventilation slots so that the ventilation slots are partially open.

[0019] Preferably, the adjusting rod includes an adjusting part, a connecting part and a clamping part, and the adjusting rod is made of the adjusting part, the connecting part and the clamping part which are fixedly connected in sequence and integrally formed, the width of the adjusting part and the clamping part is greater than that of the connecting part, a transmission groove is provided on one side of the heat-conducting rod, and the adjusting part is slidably sleeved in the transmission groove, and the length of the transmission groove of different heat-conducting rods corresponding to the same sliding plate increases sequentially along the pushing direction of the grate plate group.

[0020] The present invention has the following beneficial effects:

[0021] 1. The present invention drives the upper grate, middle grate and lower grate of different sections on the reciprocating grate to move respectively through the regulating mechanism, and adjusts the frequency of pushing materials according to the intensity of the gasification reaction of the corresponding section detected by the gasifier sensor. The materials are pushed quickly in the intense reaction section and slowly in the gentle reaction section to avoid incomplete combustion of biomass fuel or long-term retention of ash and slag, which may lead to coking. In addition, the number of ventilation holes arranged on the upper grate, middle grate and lower grate is reduced successively. As the reaction proceeds, the raw material layer in the forward direction of the pushing material is consumed and its thickness is reduced, so that the thickness of the raw material layer is matched with the air intake of the gasifier, and the formation of wind tunnels by perforation of the material layer is avoided, so as to ensure the suitable air intake of the gasifier for pushing materials at different frequencies in sections, and ensure the quality of gas transmission for gasification reaction.

[0022] 2. The present invention uses a water tank to cool down the ash layer and grate after the raw material gasification reaction, and uses the ignition holes reserved on both sides of the water tank to provide multiple ignition points, and pushes the material in sections with different frequencies to shorten the ignition time.

[0023] 3. The present invention controls the output rotation direction of the transmission mechanism through a clutch linkage transmission mechanism, and according to the frequency rate of the corresponding hydraulic rod, while the hydraulic push rod moves at different frequencies, the corresponding clutch is started according to the change trend of the material on the corresponding grate plate group, so that the clutch is in a engaged state, so that the tooth plate cooperates with the transmission structure to drive the screw to rotate in a one-way manner while pushing the material, thereby driving the sliding plate to move in the rated direction, and the adjusting rod drives the heat transfer plate to move after abutting against the inner wall of the transmission groove, and successively adjusts the ventilation hole openings on different grate plates and the contact area between the heat transfer rod and the water tank, increases the ventilation hole openings and the contact area between the heat transfer rod and the water tank when the material layer thickens, accelerates the heat dissipation, increases the air intake of the gasifier, improves the thickness of each material layer in the gasifier and the air intake, heat dissipation, and the degree of adaptation of the pushing rate, and further ensures the quality of gas produced by the gasification reaction. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0025] Figure 2 It is a structural schematic diagram of the hydraulic push rod of the present invention;

[0026] Figure 3 It is a structural diagram of the transmission mechanism of the present invention;

[0027] Figure 4 It is a schematic diagram of the cross-section structure of the grate plate in the present invention;

[0028] Figure 5 For the present invention Figure 4 A magnified view of the structure at A;

[0029] Figure 6 Schematic diagram for comparing the lengths of the adjustment slots of different heat-conducting rods of the present invention;

[0030] Figure 7 It is a schematic cross-sectional view of the structure of the sliding plate of the present invention;

[0031] Figure 8 For the present invention Figure 7 A magnified view of the structure at B in FIG.

[0032] Fig. 9 It is a schematic diagram of the transmission direction structure of two one-way transmission mechanisms in the same adjustment mechanism of the present invention.

[0033] In the figure: 1, bracket; 2, upper grate plate; 3, middle grate plate; 4, lower grate plate; 5, water tank; 6, ignition hole; 7, hydraulic push rod; 8, adjustment rod; 801, connecting part; 802, adjustment part; 803, clamping part; 9, one-way transmission mechanism; 901, ratchet; 902, external gear; 903, stop pawl; 904, spring; 10, water inlet pipe; 11, water outlet pipe; 12, upper push rod; 13, middle push rod; 14, lower push rod; 15 , sliding groove; 16, sprocket No. 1; 17, connecting gear; 18, sprocket No. 2; 19, push plate; 20, transmission shaft; 21, tooth plate; 22, transmission gear; 23, grate crossbeam; 24, connecting shaft; 25, heat conducting rod; 26, sliding plate; 27, clutch; 28, connecting groove; 29, supporting shaft; 30, ventilation hole; 31, adjustment groove; 32, ventilation groove; 33, screw; 34, heat dissipation groove; 35, fixing block; 36, transmission groove. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] Embodiment 1

[0036] See also Figure 1, Figure 2 and Figure 7 A downdraft biomass gasifier comprises a bracket 1 and a gasifier sensor. The bracket 1 is located at the bottom of the gasifier and is used to support the grate. An upper grate sheet 2 is arranged on the top of the bracket 1, a middle grate sheet 3 is arranged on the top of the bracket 1, and a lower grate sheet 4 is arranged on the top of the bracket 1. The upper grate sheet 2, the middle grate sheet 3 and the lower grate sheet 4 all include a plurality of fixed grate sheets and movable grate sheets. The upper grate sheet 2, the middle grate sheet 3 and the lower grate sheet 4 form a grate sheet group. The plurality of fixed grate sheets and the movable grate sheets of the reciprocating grate are alternately arranged. The fixed grate sheets and the movable grate sheets are all inclined and overlapped end to end to form a descending step arrangement. The upper grate sheet 2, the middle grate sheet 3 and the lower grate sheet 4 are arranged in sequence in the descending direction of the grate step, and respectively correspond to the furnace dry distillation zone, the high-temperature combustion zone and the ash secondary combustion zone in the gasifier.

[0037] One side of the bottom end of the upper grate slice 2, the middle grate slice 3 and the lower grate slice 4 are all sleeved with a grate crossbeam 23, the fixed grate slice is fixedly sleeved with the grate crossbeam 23, the movable grate slice is rotatably sleeved with the grate crossbeam 23, and a push plate 19 is slidably provided at the middle part of the bracket 1 near the bottom. The number of push plates 19 is set to several and corresponds to the movable grate slices in the upper grate slice 2, the middle grate slice 3 and the lower grate slice 4 respectively. The grate crossbeams 23 corresponding to the movable grate slices are hinged to the push plates 19 respectively, and the push plates 19 can drive the movable grate slices to reciprocate without separating from the bracket 1. A hydraulic push rod 7 is fixedly provided on one side of the bracket 1. The number of hydraulic push rods 7 is set to several and is equal to the number of push plates 19. The heights of the several hydraulic push rods 7 are different. The several hydraulic push rods 7 correspond to the several push plates 19 respectively, and connecting push rods are respectively provided between the corresponding several hydraulic push rods 7 and the several push plates 19.

[0038] The connecting push rods are divided into an upper push rod 12, a middle push rod 13 and a lower push rod 14. One ends of the upper push rod 12, the middle push rod 13 and the lower push rod 14 are fixedly connected to the end of the output end of the hydraulic push rod 7, and the other ends of the upper push rod 12, the middle push rod 13 and the lower push rod 14 are respectively hinged to the corresponding push plates 19. The upper push rod 12, the middle push rod 13 and the lower push rod 14 are of different lengths and correspond to the movable grate slices in the upper grate slice 2, the middle grate slice 3 and the lower grate slice 4 respectively. The gasifier sensor can be a temperature sensor. The gasifier sensor can also be set as a concentration sensor for detecting different combustible gases. The gasifier sensor is set in the gasifier for detecting the gasification rate in the furnace corresponding to different sections of the reciprocating grate.

[0039] The extension and retraction of the hydraulic push rod 7 respectively drives the upper push rod 12, the middle push rod 13 and the lower push rod 14 to move, and then respectively drives the corresponding push plates 19 to slide, and the push plates 19 respectively drive the corresponding movable grate plates to move back and forth, and the extension and retraction frequencies of the hydraulic push rods 7 corresponding to the upper grate plate 2, the middle grate plate 3 and the lower grate plate 4 can be different, so that the pushing and slag pushing frequencies of different sections of the reciprocating grate are different, and the extension and retraction frequencies of the hydraulic push rods 7 are controlled according to the reaction intensity of each section in the gasifier fed back by the gasifier sensor to realize segmented pushing, so that the reaction speed of the biomass fuel with air and gasification agent gas in each section is controlled within the rated range, thereby avoiding the biomass fuel being output from the gasifier before being completely burned or the biomass fuel reaction rate being too fast, resulting in too fast formation of ash and slag and easy coking, thereby improving the gasification rate of the biofuel.

[0040] The top surfaces of the upper grate slice 2, the middle grate slice 3 and the lower grate slice 4 are all provided with a plurality of through ventilation holes 30, and the bottom surfaces of the upper grate slice 2, the middle grate slice 3 and the lower grate slice 4 are all provided with air inlet grooves, which are used to prevent the bottom of the ventilation hole 30 from being blocked by the adjacent grate slices. The plurality of ventilation holes 30 on a single grate slice are evenly arranged, see Figure 1 The number of corresponding ventilation holes 30 of the upper grate slice 2, the middle grate slice 3 and the lower grate slice 4 is reduced in sequence, so that the air intake of the gasifier through the ventilation holes 30 of the upper grate slice 2, the middle grate slice 3 and the lower grate slice 4 is reduced in sequence, and the air intake of the air gasifier is allocated according to the reaction intensity of the biomass raw materials on the reciprocating grate in each section. The gasifier can be set to air. Since the biomass raw materials in the upper section react violently, there are more ventilation holes 30 on the upper grate slice 2. As the reaction proceeds, the biomass raw materials pushed to the lower section of the reciprocating grate have a thin layer, and there are fewer ventilation holes 30 on the lower grate slice 4, which improves the degree of adaptation between the air intake of the gasifier and the reaction intensity of the biomass raw materials in each section, avoids the formation of wind tunnels due to the perforation of the grate middle and rear sections in the gasifier, ensures the quality of the combustible gas produced by incomplete combustion of biomass, and provides a stable gasification reaction environment for the hydraulic push rod 7 to control the grate segmented pushing.

[0041] Embodiment 2

[0042] See also Figure 1 , Figure 2 , Figure 4 and Figure 7A water tank 5 for cooling the ash layer and the grate is fixedly arranged on the top of the bracket 1. The number of water tanks 5 is set to two and they are symmetrically arranged on both sides of the grate plate group. The water tank 5 is inclined and the degree of inclination is adapted to the degree of inclination of the grate plate group. A water inlet pipe 10 is fixedly connected to one side of the water tank 5, and a water outlet pipe 11 is fixedly connected to the other side of the water tank 5. The height of the water inlet pipe 10 is lower than the water outlet pipe 11. The water tank 5 is connected to the cooling mechanism through the water inlet pipe 10 and the water outlet pipe 11, so that cooling water enters the water inlet pipe 10 and enters the water tank 5 and then flows out from the water outlet pipe 11. The cooling water takes away the heat of the ash layer on the grate plate group through the water tank 5 to prevent overheating and coking, and absorbs the waste heat of the ash layer, while reducing the temperature of the grate to prevent the grate from overheating. The grate crossbeam 23 corresponding to the fixed grate is fixedly connected to the side wall of the water tank 5, and ignition holes 6 for the heating rod to pass through are opened on both sides of the water tank 5.

[0043] When the gasifier is started, when the material layer in the furnace is piled to the rated thickness, several electric heating rods are inserted into the bottom of the material layer through the corresponding ignition holes 6, and the gasifier is ignited by power-on heating. The ignition method is simple and fast, and the ignition points in the furnace are evenly distributed, which shortens the ignition time. In addition, the hydraulic push rod 7 is used to control the frequency of pushing the material in the grate section. At startup, the upper grate slice 2 and the middle grate slice 3 are activated, and the lower grate slice 4 is stopped. No slag is discharged, and the upper grate slice 2 is activated more frequently than the middle grate slice 3 to ensure startup efficiency.

[0044] Embodiment 3

[0045] See also Figure 1-Figure 5 , Figure 7 and Fig. 9 On the basis of the second embodiment, a sliding groove 15 is provided on one side of the water tank 5, the number of the sliding grooves 15 is set to two and the two sliding grooves 15 correspond to the middle grate sheet 3 and the lower grate sheet 4 respectively, a sliding plate 26 is slidably sleeved in the sliding groove 15, a fixed block 35 is fixedly connected to one side of the sliding groove 15, a screw 33 is rotatably sleeved at the midpoint of the fixed block 35, the screw 33 only rotates circumferentially relative to the fixed block 35, the screw 33 is threadedly sleeved with the fixed block 35, a connecting groove 28 is provided on one side of the sliding plate 26, the number of the connecting grooves 28 is set to several and the number is adapted to the number of rows of grate sheets formed by a single sliding groove 15, an adjusting rod 8 is slidably clamped in the connecting groove 28, one end of the adjusting rod 8 is connected to a heat conducting rod 25, and the heat conducting rods 25 on both sides are respectively located on both sides of the grate sheet group.

[0046] One end of the screw rod 33 is fixedly connected to the first sprocket 16. The bottom of the bracket 1 is rotatably connected to the support shaft 29 through the rotating shaft. The number of the support shaft 29 is set to two and corresponds to the middle push rod 13 and the lower push rod 14 respectively. One end of the support shaft 29 is fixedly sleeved with a transmission gear 22. Figure 2The connecting push rod is composed of two hinged connecting rods, one of the two connecting rods is fixedly connected to the hydraulic rod, and the other connecting rod is hinged to the push plate 19. The bottom of the connecting rod near the hydraulic push rod 7 in the middle push rod 13 and the lower push rod 14 is fixedly connected with a tooth plate 21 adapted to the transmission gear 22, and the tooth plate 21 is meshed with the transmission gear 22. Both sides of the bottom of the bracket 1 are rotatably connected to the transmission shaft 20 through a rotating shaft, and the bottom of the bracket 1 is rotatably connected to the connecting shaft 24 through a rotating shaft. The transmission shaft 20 is transmission-connected to the support shaft 29 through a clutch 27, and one side of the transmission shaft 20 is fixedly connected to a one-way transmission mechanism 9.

[0047] Specifically, the one-way transmission mechanism 9 includes a ratchet 901 and an external gear 902. The external gear 902 is rotatably connected to the bracket 1 through a rotating shaft, and the ratchet 901 is fixedly connected to the corresponding transmission shaft 20. Fig. 9 The transmission directions of the one-way transmission mechanisms 9 on both sides of the bracket 1 are opposite, that is, the directions in which the external gear 902 can rotate are opposite. The inner side of the external gear 902 is rotatably connected with a stop pawl 903, and one end of the stop pawl 903 is fixedly connected with a spring 904. When the ratchet 901 rotates in the rated direction relative to the external gear 902, the spring 904 pushes the stop pawl 903 to be embedded between the ratchet teeth of the ratchet 901, thereby driving the external gear 902 to rotate. Conversely, when the ratchet 901 rotates in the other direction, the ratchet teeth push the stop pawl 903 away, and the ratchet 901 rotates relative to the external gear 902. Both sides of the connecting shaft 24 are fixedly connected with connecting gears 17, and the connecting gear 17 is meshed with the external gear 902.

[0048] The middle push rod 13 and the lower push rod 14 extend and retract to drive the corresponding toothed plate 21 to move back and forth respectively, and control the clutch 27 on one side to link the corresponding support shaft 29 and the transmission shaft 20. The toothed plate 21 drives the transmission gear 22 to rotate, and the transmission gear 22 drives the support shaft 29 to rotate. The support shaft 29 drives the ratchet 901 to rotate along the rated direction, and the spring 904 and the stop claw 903 drive the outer gear 902 to rotate along the rated direction. Since the transmission directions of the one-way transmission mechanisms 9 on both sides are opposite, that is, when the toothed plate 21 moves back and forth, the two clutches 27 respectively control the corresponding outer gear 902 to rotate in the opposite rated direction, and the outer gear 902 drives the connecting gear 17 to rotate, and then drives the connecting shaft 24 to rotate, so that when the toothed plate 21 moves back and forth, the two couplings on both sides are linked, and the connecting shaft 24 can rotate unidirectionally in the two corresponding rated directions respectively.

[0049] Both ends of the connecting shaft 24 are fixedly connected with a No. 2 sprocket 18 that cooperates with the No. 1 sprocket 16. The No. 2 sprocket 18 is connected to the No. 1 sprocket 16 through a chain transmission. When the action frequency of the hydraulic push rod 7 is different, the difference in pushing speed between adjacent grate slices may easily lead to a decrease in the material thickness of the grate slice with a fast pushing speed at the rear end, and an increase in the material thickness of the grate slice with a slow pushing speed at the rear end. The clutch 27 corresponding to the middle grate slice 3 or the lower grate slice 4 is started to put the clutch 27 in an engaged state, so that the middle push rod 13 drives the corresponding connecting shaft 24 to rotate along the rated direction, the connecting shaft 24 drives the No. 2 sprocket 18 to rotate, the No. 2 sprocket 18 drives the No. 1 sprocket 16 to rotate through the chain, the No. 1 sprocket 16 drives the corresponding screw 33 to rotate, the rotation of the screw 33 drives the sliding plate 26 to move, and the sliding plate 26 drives several adjusting rods 8 to move.

[0050] Since the movable grate piece is in a reciprocating state, the heat-conducting rod 25 is slidably sleeved in the corresponding grate piece. The movement of the movable grate piece drives the corresponding heat-conducting rod 25 to move, and then drives the adjusting rod 8 to move. A heat dissipation groove 34 is opened on one side of the water tank 5, and one end of the adjusting rod 8 is embedded in the heat dissipation groove 34. The length of the heat dissipation groove 34 is adapted to the moving distance of the corresponding adjusting rod 8. The length of the connecting groove 28 corresponding to the movable grate piece is adapted to the sliding distance of the adjusting rod 8. When the adjusting rod 8 slides relative to the sliding plate 26, the sliding plate 26 can drive the adjusting rod 8 to move. The adjusting rod 8 drives the heat-conducting rod 25 to move in the rated direction, and the heat-conducting rod 25 is slidably sleeved with the water tank 5.

[0051] When the pushing rate of the corresponding grate slice is small, for example, after controlling the rates of the middle push rod 13 and the upper push rod 12, when the pushing frequency of the middle grate slice 3 is less than that of the upper grate slice 2, the material thickness on the middle grate slice 3 increases, and the corresponding clutch 27 is started synchronously, so that the adjusting rod 8 drives the heat-conducting rod 25 to move toward the water tank 5, and the heat-conducting rod 25 moves synchronously by a rated distance for each reciprocating movement of the corresponding middle push rod 13, the contact area between the heat-conducting rod 25 and the water tank 5 increases, the material thickness increases, the material amount of the gasification reaction in the corresponding area increases, and the heat dissipation rate of the area is increased. Conversely, the contact area between the heat-conducting rod 25 and the water tank 5 is reduced. When the material decreases, the heat dissipation rate is reduced to avoid energy waste due to excessive heat dissipation or ash coking due to insufficient heat dissipation.

[0052] Embodiment 4

[0053] See also Figure 1 , Figure 2 , Figure 4 , Figure 5 , Figure 7 and Figure 8On the basis of the third embodiment, the tops of the lower grate sheet 4 and the middle grate sheet 3 are both provided with through ventilation slots 32, and the ventilation slots 32 are connected to the air inlet slots at the bottom. The heat-conducting rods 25 are used to conduct heat and close the ventilation slots 32. The heat-conducting rods 25 on both sides are respectively located on both sides of the grate sheet group. The tops of the heat-conducting rods 25 are provided with through adjustment slots 31, and the adjustment slots 31 correspond to the ventilation slots 32 so that the ventilation slots 32 are partially opened. When the amount of material increases, the heat-conducting rods 25 move in the rated direction. While increasing the heat dissipation, the area of ​​the area corresponding to the adjustment slots 31 and the ventilation slots 32 increases, and the air intake of the gasifier is increased synchronously. On the contrary, when the pushing frequency of the corresponding part is high and the pushing frequency of the front end of the corresponding part is low, the amount of material on the grate sheet decreases, the reaction amount decreases, and while reducing the heat dissipation, the heat-conducting rods 25 move to reduce the area of ​​the area corresponding to the adjustment slots 31 and the ventilation slots 32, reduce the air intake, and synchronously adjust the air intake of the gasifier to further ensure the quality of gas production.

[0054] Embodiment 5

[0055] See also Figure 1 , Figure 2 , Figure 4-Figure 8 On the basis of the fourth embodiment, the adjusting rod 8 includes an adjusting portion 802, a connecting portion 801 and a clamping portion 803. The adjusting rod 8 is made of the adjusting portion 802, the connecting portion 801 and the clamping portion 803, which are fixedly connected in sequence and integrally formed. The width of the adjusting portion 802 and the clamping portion 803 is greater than that of the connecting portion 801. The clamping portion 803 is slidably sleeved in the connecting groove 28. A transmission groove 36 is provided on one side of the heat conducting rod 25. The adjusting portion 802 is slidably sleeved in the transmission groove 36. Figure 6 The lengths of different heat-conducting rods 25 corresponding to the same sliding plate 26 along the transmission groove 36 in the pushing direction of the grate plate group are increased successively, so that when the adjusting rod 8 moves, the adjusting rod 8 first presses against the inner wall of the transmission groove 36 and then pushes the heat-conducting rod 25 to move, and the heat-conducting rods 25 located in the pushing direction are driven to move successively, and different heat-conducting rods 25 adjust the heat conduction and air intake in turn, so that the part with the thickness that changes first is adjusted first, thereby further ensuring the adjustment effect.

[0056] The method of use (working principle) of the present invention is as follows:

[0057] Through the hydraulic push rod 7, the upper push rod 12, the middle push rod 13 and the lower push rod 14 are respectively driven to move the upper grate 2, the middle grate 3 and the lower grate 4 at different frequencies under the corresponding air intake environment, so that the pushing rate is adapted to the reaction intensity of the corresponding section of the gasifier. At the same time, the water tank 5 cools down the grate and the ash layer. The reserved ignition holes 6 on both sides of the water tank 5 ignite evenly during ignition and cooperate with the segmented frequency control to improve the convenience of ignition. The middle push rod 13 and the lower push rod 14 drive the adjustment rod 8 to move through the transmission structure. Different adjustment rods 8 drive the heat conducting rod 25 to move in turn, adjust the contact area between the heat conducting rod 25 and the water tank 5 and the size of the corresponding area of ​​the ventilation slot 32 and the adjustment slot 31, so that when the relative frequency of the grate slices changes, the part of the material thickness that changes first is adjusted first, so as to improve the adaptability of the amount of material participating in the reaction in each section of the furnace to the air intake, heat dissipation and pushing rate, and ensure the quality of gas produced by the gasification reaction.

Claims

1. A downdraft biomass gasifier, comprising a support (1) and a gasifier sensor, wherein a grate plate group is arranged on the top of the support (1), characterized in that: The grate plate group comprises an upper grate plate (2), a middle grate plate (3) and a lower grate plate (4), wherein the upper grate plate (2), the middle grate plate (3) and the lower grate plate (4) each comprise a plurality of fixed grate plates and movable grate plates, wherein the plurality of fixed grate plates and movable grate plates are arranged alternately, wherein the fixed grate plates and the movable grate plates are arranged in an inclined manner and overlap each other end to end to form a stepped arrangement, and wherein the upper grate plate (2), the middle grate plate (3) and the lower grate plate (4) are arranged in sequence in the grate stepped pushing direction; The gasifier sensor is arranged in the gasifier for detecting the intensity of the gasification reaction in the furnace corresponding to different sections of the reciprocating grate. The bottom of the bracket (1) is provided with an adjustment mechanism. The adjustment mechanism can drive the upper grate plate (2), the middle grate plate (3) and the lower grate plate (4) to move at different frequencies according to the intensity of the reaction in each section detected by the gasifier sensor, and adjust the pushing frequency in sections. The adjustment mechanism can adjust the air intake and heat dissipation of each section of the upper grate plate (2), the middle grate plate (3) and the lower grate plate (4) according to the changing trend of the amount of biomass material after the adjustment of different frequencies. When the amount of biomass material in the corresponding section increases, the air intake and heat dissipation of different grate plates are increased successively as the reciprocating pushing is carried out. When the amount of biomass material in the corresponding section decreases, the air intake and heat dissipation of different grate plates are reduced successively.

2. A downdraft biomass gasifier according to claim 1, characterized in that: The bottom ends of the upper grate plate (2), the middle grate plate (3) and the lower grate plate (4) are sleeved with a grate crossbeam (23) on one side, the adjustment mechanism comprises a push plate (19), the bracket (1) is slidably connected to the push plate (19), the number of the push plates (19) is set to be several, one side of the bracket (1) is fixedly provided with several hydraulic push rods (7) corresponding to the number of the push plates (19), and connecting push rods are provided between the several hydraulic push rods (7) and the corresponding push plates (19), and the connecting push rods are composed of two hinged connecting rods; A plurality of the hydraulic push rods (7) can be extended and retracted at different frequencies to cooperate with the push plate (19), the grate crossbeam (23) and the connecting push rod, thereby driving the corresponding movable grate plates in the upper grate plate (2), the middle grate plate (3) and the lower grate plate (4) to move at different rated frequencies. The plurality of connecting push rods are respectively an upper push rod (12), a middle push rod (13) and a lower push rod (14). One end of the connecting push rod is fixedly connected to the hydraulic push rod (7), and the other end of the connecting push rod is hinged to the corresponding push plate (19).

3. A downdraft biomass gasifier according to claim 2, characterized in that: The top surfaces of the upper grate slice (2), the middle grate slice (3) and the lower grate slice (4) are all provided with a plurality of through ventilation holes (30); the plurality of ventilation holes (30) on a single grate slice are evenly arranged; the number of ventilation holes (30) arranged on a single grate slice corresponding to the upper grate slice (2), the middle grate slice (3) and the lower grate slice (4) is reduced in sequence, so that the number of ventilation holes (30) corresponding to a thin layer of biomass raw materials on the grate is small, and the number of ventilation holes (30) corresponding to a thick layer of biomass raw materials on the grate is large.

4. A downdraft biomass gasifier according to claim 3, characterized in that: A water tank (5) for cooling the ash layer and the grate is fixedly arranged on the top of the support (1); the number of the water tanks (5) is set to two and they are symmetrically arranged on both sides of the grate plate group; one side of the water tank (5) is fixedly connected to a water inlet pipe (10), and the other side of the water tank (5) is fixedly connected to a water outlet pipe (11); the water tank (5) is connected to the cooling mechanism through the water inlet pipe (10) and the water outlet pipe (11).

5. The downdraft biomass gasifier according to claim 4, characterized in that: Ignition holes (6) for the heating rod to pass through are provided on both sides of the water tank (5).

6. The downdraft biomass gasifier according to claim 4, characterized in that: A sliding groove (15) is provided on one side of the water tank (5), the number of the sliding grooves (15) is set to two and the two sliding grooves (15) correspond to the middle grate plate (3) and the lower grate plate (4) respectively, the adjustment mechanism also includes a sliding plate (26), the sliding plate (26) is slidably arranged in the sliding groove (15), and a fixed block (35) is fixedly connected to one side of the sliding groove (15); A screw rod (33) is rotatably sleeved at the midpoint of the fixed block (35), a connecting groove (28) is provided on one side of the sliding plate (26), a heat dissipation groove (34) is provided on one side of the water tank (5), the number of the connecting grooves (28) is set to be several, an adjusting rod (8) is slidably clamped in the connecting groove (28), and one end of the adjusting rod (8) is connected to the heat conducting rod (25).

7. The downdraft biomass gasifier according to claim 6, characterized in that: One end of the screw rod (33) is fixedly connected to a No. 1 sprocket (16), the bottom of the bracket (1) is rotatably connected to a support shaft (29) via a rotating shaft, the number of the support shafts (29) is set to two, one end of the shaft body of the support shaft (29) is fixedly sleeved with a transmission gear (22), the bottoms of the middle push rod (13) and the lower push rod (14) are fixedly connected to a toothed plate (21) adapted to the transmission gear (22), the toothed plate (21) is meshed with the transmission gear (22), both sides of the bottom of the bracket (1) are rotatably connected to a transmission shaft (20) via a rotating shaft, and the bottom of the bracket (1) is rotatably connected to a connecting shaft (24) via a rotating shaft; The transmission shaft (20) is connected to the support shaft (29) through a clutch (27); one side of the transmission shaft (20) is fixedly connected to a one-way transmission mechanism (9); both sides of the connecting shaft (24) are fixedly connected to connecting gears (17); the one-way transmission mechanism (9) drives the connecting gear (17) to rotate in one direction, and the transmission directions of the one-way transmission mechanisms (9) on both sides of the bracket (1) are opposite; both ends of the connecting shaft (24) are fixedly connected to a second sprocket (18) matched with the first sprocket (16); the second sprocket (18) is connected to the first sprocket (16) through chain transmission.

8. The downdraft biomass gasifier according to claim 7, characterized in that: The one-way transmission mechanism (9) comprises a ratchet (901) and an external gear (902); the external gear (902) is rotatably connected to the bracket (1) via a rotating shaft; the ratchet (901) is fixedly connected to a corresponding transmission shaft (20); a stop pawl (903) is rotatably connected to the inner side of the external gear (902); one end of the stop pawl (903) is fixedly connected to a spring (904); and a connecting gear (17) is meshed with the external gear (902).

9. The downdraft biomass gasifier according to claim 7, characterized in that: The tops of the lower grate plate (4) and the middle grate plate (3) are both provided with through ventilation slots (32); the heat conducting rod (25) is used to conduct heat and close the ventilation slots (32); the tops of the heat conducting rods (25) are provided with through adjustment slots (31); the adjustment slots (31) partially correspond to the ventilation slots (32) so that the ventilation slots (32) are partially opened.

10. The downdraft biomass gasifier according to claim 9, characterized in that: The adjusting rod (8) comprises an adjusting portion (802), a connecting portion (801) and a clamping portion (803); the adjusting rod (88) is formed by fixing the adjusting portion (802), the connecting portion (801) and the clamping portion (803) in sequence and integrally connected; the width of the adjusting portion (802) and the clamping portion (803) is greater than that of the connecting portion (801); a transmission groove (36) is provided on one side of the heat-conducting rod (25); the adjusting portion (802) is slidably sleeved in the transmission groove (36); and the lengths of the transmission grooves (36) of different heat-conducting rods (25) corresponding to the same sliding plate (26) increase in sequence along the pushing direction of the grate plate group.

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