CN205535775U - Hood for circulating fluidized bed - Google Patents

Abstract

The utility model discloses a hood for circulating fluidized bed, wherein, circulating fluidized bed includes the fluidized bed body, it is inside and with fluidized bed body internal partitioning for the fluidization chamber that is located the top with be located the air distribution plate of the plenum of below and arrange a plurality of hood on the air distribution plate to locate the fluidized bed body. The hood include inner tube, cover put including outside of tubes portion the outer tube and from the lateral wall interval downward sloping of outer tube and with two at least play tuber pipes of the inside intercommunication of outer tube, the air intake of inner tube on the last surface surround air distribution plate of air distribution plate upwards extends and the top is sealed, the roof that the diapire of outer tube was connected to outer wall and the outer tube of inner tube lies in the top on the top of inner tube, the inner tube lies in and is equipped with a plurality of wind hole on the pipe wall of outer tube inside.

Description

Recirculating fluidized bed blast cap

Technical field

This utility model relates to a kind of boiler plant, particularly relates to a kind of recirculating fluidized bed.

Background technology

In the face of increasingly serious environmental problem and energy crisis, energy-conservation subtracting all is being advocated energetically in the whole world How row, especially for the boiler related industry that power consumption and pollution are the most more serious, carry out energy-conservation subtracting Row transformation, have become as various equivalent modifications design this kind equipment time have to consider because of Element.

As a example by fluid bed, the temperature of its smoke outlet would generally reach 800 degrees centigrade Flue gas is entrained with substantial amounts of flue dust, if these are directly discharged to environment with the flue gas of flue dust In, not only can cause energy waste, also environment can be caused a certain degree of destruction.

As Chinese patent 201320869949.6 discloses a kind of cooperation-removal PM2.5 and desulfurization Circulating fluidized bed system, it burner hearth including being sequentially connected, cyclone separator, air preheater, Humidifying device, demister and cleaner unit, material returning device is connected with burner hearth and cyclone separator respectively. But, the air vent of the cyclone separator in circulating fluidized bed system designed by this patent is positioned at Side, its negative pressure produced in separator causes flue dust to be easily blocked between separator and burner hearth In refeed line, not only it is difficult to the effect of circulation, and is difficult to reach to efficiently separate flue dust Environment protecting.

The and for example recirculating fluidized bed of a kind of multi-stage material return disclosed in Chinese patent 200710063369.7 System, is connected in sequence by main bed, separator, material returning device, wherein, material returning device be two or Two or more, connects along short transverse, i.e. separator bottom solid outlet pipe and the returning charge of the top Device descending branch is connected, and this material returning device outlet is connected with the descending branch of material returning device below, under The outlet of the material returning device of side is connected with main bed bottom；In addition to the material returning device of bottom, each returning charge The ascent stage top of device is provided with the pressure-equalizing pipe communicated with main bed.But, designed by this patent Circulating fluidized bed system needs to use the series connection of multi-stage material return device to solve circulating fluidized bed system returning charge not Smooth problem, structure is the most complicated, and fails to disclose how to recycle the high temperature cigarette of discharge Gas.

Therefore it provides a kind of New Cycle fluid bed becomes urgent problem in the industry.

Summary of the invention

The purpose of this utility model is to provide a kind of recirculating fluidized bed blast cap, and it can effectively reduce The smoke content of the flue gas being emitted in environment, and can fully recycle the high-temperature flue gas of discharge Energy, it is achieved the effect of energy-conserving and environment-protective.

To achieve these goals, this utility model provides a kind of recirculating fluidized bed blast cap, its In, recirculating fluidized bed includes fluid bed body, is located at fluid bed body interior and by fluid bed body Inside is divided into fluidising chamber above and the air distribution plate of air compartment being positioned at lower section and is arranged in Several blast caps on air distribution plate.Blast cap include inner tube, be nested with the outer tube outside inner tube and from The sidewall spacers of outer tube is downward-sloping and at least two discharge pipes connecting with outer tube, inner tube from The upper surface of air distribution plate upwardly extends and top closure around the air inlet on air distribution plate, outer tube The roof of outer wall and outer tube that diapire is connected to inner tube is positioned at the top on the top of inner tube, and inner tube is positioned at The tube wall of outer tube is provided with several air holes.

According to a kind of alternative scheme of the present utility model, also provide for a kind of recirculating fluidized bed, including: Fluid bed, fluid bed includes fluid bed body, is located at fluid bed body interior and by fluid bed body Inside be divided into fluidising chamber above and be positioned at lower section air compartment air distribution plate, be arranged in cloth wind Several on plate are for the blast cap by fluidized wind injection to fluidising chamber；Flue, flue It is connected on the sidewall of fluid bed body the flue gas will produce in fluidising chamber discharge；Wherein, circulation Fluid bed blast cap also includes that the lower aerofluxus being sequentially arranged along the flow of flue gas direction of flue divides From device and residual heat using device；Lower discharge air separator includes separator body, is located at separator body High-temperature flue gas entry that sidewall is connected with flue, it is vertical at separator body inner chamber and top Away from separator body roof, outlet at bottom passes through flue and residual heat using device to portion's entrance The lower aiutage that is connected and being located at bottom separator body is connected by refeed line with fluidising chamber The returning charge outlet connect；Residual heat using device includes the outlet at bottom by flue Yu lower aiutage The dedusting smoke inlet being connected, the low-temperature flue gas being connected to chimney by flue are exported, lead to Cool air inlet that supercooled air pipeline and the first blower fan are connected and by hot-air pipeline and wind The hot air outlet that room is connected.

Selectively, the bottom of separator body is formed with tapered portion, and returning charge outlet is formed at taper On the sidewall in portion.

Selectively, high-temperature flue gas enters separator body with the tangential direction of separator body, in Rotate with the flue dust in separating flue between inwall and the outer wall of lower aiutage of separator body, remove Flue gas after dirt enters lower aiutage with direction from top to bottom by the top entry of lower aiutage Discharge.

Selectively, residual heat using device can be single air preheater, air preheater bag Include shell, housing interior volume is divided in the most parallel flue gas flow path and air flow circuit every If plate and the dry heat pipe being located in median septum, wherein, the evaporation ends of heat pipe extends flue gas In stream, the condensation end of heat pipe extends in fluid flowing path.The two ends of flue gas flow path are formed respectively and remove Dirt smoke inlet and low-temperature flue gas outlet, the two ends of air flow circuit form cool air inlet and heat respectively Air outlet slit.Working medium in the heat pipe of air preheater can be to be applicable to 1000 degrees centigrade works The working medium such as the Liquid Sodium of condition or potassium.

Preferably, there is backflow in flue branch between lower discharge air separator and residual heat using device Flue gas pipeline, backflow flue gas pipeline be connected with hot-air pipeline and be provided with in junction blender with Part heat smoke from lower discharge air separator is mixed with the hot-air from residual heat using device Form gaseous mixture.

Selectively, backflow flue gas pipeline be back to the 10～20% of amount of flue gas emission in blender with Hot-air mixes, and is preferably back to blender by the 15% of amount of flue gas emission.

Wherein, the temperature in backflow flue gas pipeline about 800 degrees Celsius, the hot cigarette of oxygen content about 5% Gas is mixing with the temperature in hot-air pipeline about 200 degrees Celsius, the hot-air of oxygen content about 21% Device is formed temperature about 500 degrees Celsius, the gaseous mixture of oxygen content about 13%.

Preferably, blender includes blender body, the hot-air of being located at blender body one end enters Mouthful, be located at blender body side heat smoke entrance, be located at blender body interior gas mix Close chamber and be located at the mixed gas outlet of the other end of blender body, wherein, gas mixing chamber In neighbouring mixed gas outlet be provided with rotary blade.

Preferably, on hot-air pipeline, downstream in mixer outlet is provided with and is connected with air compartment Airduct, airduct includes airduct body, the gaseous mixture entrance being located at airduct body one end, is located at airduct The wind chamber of body interior, the mixed gas outlet being located at the other end of airduct body and neighbouring mixing The first homogenizing plate group that gas outlet is arranged, the first homogenizing plate group includes that horizontal arrangement is extremely from top to bottom Few three the first homogenizing plates to be separated at least four connected respectively with air compartment by mixed gas outlet First split channel.

Selectively, at least three the first homogenizing plate is the most equidistantly arranged.

Selectively, being provided with the second homogenizing plate group in air compartment, the second homogenizing plate group includes from air distribution plate Lower surface be spaced at least three the second homogenizing plate of downwardly extending, at least three the second homogenizing plate Development length along away from airduct direction be incremented by be separated out in air compartment at least four respectively with often Second split channel of individual first split channel correspondence connection.

Selectively, at least three the second homogenizing plate prolongs vertically downward from the lower surface of air distribution plate respectively Stretch and at least three the second homogenizing plate is the most equidistantly arranged.

Selectively, with from least three the second homogenizing plate away from airduct to the direction of neighbouring airduct End respectively correspondingly concordant with the horizontal direction of at least three the first homogenizing plate from bottom to top.

Preferably, each blast cap includes inner tube, is nested with at the outer tube outside inner tube and from outer tube Sidewall spacers is downward-sloping and at least two discharge pipes connecting with outer tube, and inner tube is from air distribution plate Upper surface upwardly extend and top closure around each air inlet on air distribution plate, the end of outer tube The roof of outer wall and outer tube that wall is connected to inner tube is positioned at the top on the top of inner tube, wherein, inner tube The tube wall being positioned at outer tube is provided with several air holes so that the gaseous mixture in air compartment passes through air intake Mouth sprays to the space between outer wall of inner tube and outer tube wall again via extremely via several air holes Few two discharge pipes spray the upper surface to air distribution plate.

Selectively, inner tube be positioned at outer tube a length of whole inner tube length 2/3rds to 5/6ths.Distance between end and the upper surface of air distribution plate of discharge pipe is whole inner tube length 1/1st to three/6th.Distance between outer tube diapire and the upper surface of air distribution plate is whole / to three/6th of inner tube length.Distance between inner tube top and outer tube roof is whole / to five/10th of individual inner tube length.Outer tube diameter be two times of diameter of inner pipe to five Times.

Selectively, including three the isometric discharge pipes arranged at equal intervals around outer tube wall, three Two times to five times of a diameter of outer tube diameter of the end place circumference of individual discharge pipe.

Selectively, the angle between discharge pipe and the central axis of inner tube is set to 30～60 degree, It is preferably 40～50 degree, ratio such as from about 45 degree.

Selectively, can pass through welding, riveting bottom inner tube, threaded or alternate manner solid Surely the upper surface of air distribution plate it is connected to.

Preferably, several air holes are that array-like is distributed in inner tube and is positioned on the tube wall of outer tube, Or being divided at least three row at equal intervals along tube wall circumference, each column includes along tube wall the most at equal intervals At least ten air holes arranged.Wherein, the diameter of air holes can be set as diameter of inner pipe ten/ 1/1st to three, such as 1/5th.

Preferably, backflow flue gas pipeline is provided with for regulating backflow flue gas stream at neighbouring blender First valve of amount, hot-air pipeline is provided with for regulating hot air flowrate at neighbouring blender The second valve.

Selectively, the first valve and/or the second valve can be operated pneumatic valve, electromagnetic valve, hands Movable valve or other valve that can realize controlling traffic engineering capability.

Preferably, the second blower fan it is provided with between blender and airduct to carry gaseous mixture in airduct.

Preferably, recirculating fluidized bed blast cap also includes entering with the coal dust of setting on the sidewall of fluidising chamber The screw feeder that is connected of mouth to be delivered to fluidized bed combustion in fluidising chamber by coal dust.

Preferably, residual heat using device include being sequentially communicated from bottom to top setting for secondary ash disposal Dedusting chamber, for steam being heated into the superheater of superheated steam, being used for becoming to steam by cool water heating The economizer of vapour and for cold air is heated into the air preheater of hot-air, wherein, removes Dirt smoke inlet is formed at a sidewall of dedusting chamber, and hot air outlet is formed at the one of air preheater Sidewall, cool air inlet is formed at another sidewall of air preheater.

Selectively, dedusting chamber uses cyclone dust removal or electrostatic precipitation mode, to remove cigarette further Flue dust in gas.

Selectively, superheater is convection superheater, including several superheater tubes, flows between pipe Logical flue gas, flowing steam in pipe, it is preferable that superheater tube is the extended surface tube of band longitudinal rib or carries ring-type The gilled tube of circle rib.

Selectively, economizer is tubulation structure, and circulate between pipe flue gas, circulation water in pipe, and it leads to Cross the heat energy in recovered flue gas to add hot water.

Selectively, air preheater is the plate air preheater being made up of steel plate, enters air The cold air of preheater and the heat smoke of reverse flow carry out heat exchange and form hot-air.

The beneficial effects of the utility model are: (1), lower discharge air separator use the mode of lower aerofluxus Efficiently solve the problem that flue dust is blocked in the refeed line between separator and fluid bed, it is ensured that cigarette Dirt can more move smoothly through in refeed line is delivered to fluidising chamber and carry out second-time burning, it is achieved energy-saving ring The effect protected；(2), residual heat using device only with Multi-stage heat conversion equipment, does not effectively utilizes The heat of high temperature of heat smoke, and the dirt pocket arranged can carry out final dusting to flue gas further Process, it is achieved the environment protecting of low temperature low smoke content fume emission；(3), divide from lower aerofluxus After the partial fume of device mixes with the hot-air carrying out heat exchange from residual heat using device permissible Circulation is delivered in the air compartment of fluid bed, is possible not only to produce the material to fluidisation is indoor and fluidizes Effect, simultaneously can also realize high-temperature and low-oxygen combustion so that oxynitride in the flue gas of discharge Content is low, energy-conserving and environment-protective；The setting of (4) first homogenizing plate groups and the second homogenizing plate group makes air compartment Interior gas can spray in fluidising chamber the most equably, it is ensured that carrying out steadily smoothly of fluidisation；(5) The blast cap structure of bleed type downwards, on the one hand makes fluidized reaction more uniform, on the other hand avoids Bed leaks in air compartment via blast cap；(6) in blender the setting of impeller not only make heat smoke and The mixing of hot-air is more uniform, and can also eliminate from the Mars in heat smoke, it is ensured that peace Entirely.

Accompanying drawing explanation

Fig. 1 is the organigram of recirculating fluidized bed of the present utility model.

Fig. 2 is the organigram of blast cap of the present utility model.

Fig. 3 is the organigram of blender of the present utility model.

Fig. 4 is along line A-A cross-sectional schematic in Fig. 1.

Detailed description of the invention

Refer to Fig. 1, according to a kind of non-limiting embodiment of the present utility model, ciculation fluidized Bed includes: fluid bed 100, lower discharge air separator 200, residual heat using device 300 and flue gas Pipeline GL.

Wherein, fluid bed 100 includes fluid bed body 110, is located at fluid bed body 110 inside Air distribution plate 140, air distribution plate 140 is divided into stream above by internal for fluid bed body 110 Change room 120 and be positioned at the air compartment 130 of lower section, air distribution plate 140 is placed with several blast caps 150, Thus utilize blast cap 150 just can be sprayed to fluidising chamber 120 by the fluidized wind from air compartment 130.

In this non-limiting embodiment, as in figure 2 it is shown, each blast cap 150 includes inner tube 1501, it is nested with at the outer tube 1502 outside inner tube 1501 and from the sidewall spacers of outer tube 1502 Downward-sloping and internal with outer tube 1,502 two discharge pipes 1503 and 1504 connected, inner tube 1501 From the upper surface of air distribution plate 140 around each air inlet (not shown) on air distribution plate 140 upwards Extend and top closure.The diapire BW of outer tube 1502 is connected to the outer wall of inner tube 1501 and outer The roof of pipe 1502 is positioned at the top on the top of inner tube 1501.Wherein, outside inner tube 1501 is positioned at The tube wall of the pipeline section within pipe 1502 is provided with several air holes 1505 so that in air compartment 130 Gaseous mixture is sprayed to inner tube 1501 outer wall and outer tube via several air holes 1505 by air inlet Spray to air distribution plate via two discharge pipes 1503 and 1504 again behind space between 1502 inwalls The upper surface of 140.Thus, the blast cap structure utilizing this downward bleed type is possible not only to make fluidisation Reaction is more uniform, but also avoids bed and leak in air compartment via blast cap.For the ease of peace Dress and the discharge of gas, can set the length that inner tube 1501 is positioned within outer tube 1502 the most whole 2/3rds of individual inner tube 1501 length, the end of discharge pipe 1503 and 1504 and air distribution plate 140 Upper surface between distance be about 1/3rd of whole inner tube 1501 length.

Continue back at Fig. 1, in this non-limiting embodiment, fluidisation combustion in fluidising chamber 120 Burn the flue gas produced to depend on by being connected to the flue GL of the side wall upper part of fluid bed body 110 Secondary flow to lower discharge air separator 200 and residual heat using device 300.Lower discharge air separator 200 is wrapped Include separator body 210, be located at being connected with flue GL of separator body 210 sidewall High-temperature flue gas entry 220, be vertical at separator body 210 inner chamber and top entry away from point From device body 210 roof, outlet at bottom passes through flue GL and residual heat using device 300 phase The lower aiutage 230 that connects and be located at bottom separator body 210 and lead to fluidising chamber 120 Cross the returning charge outlet 240 that refeed line FL is connected.

Refer to Fig. 4, high-temperature flue gas entry 220 is tangentially-arranged along separator body 210 sidewall. Thus, the high-temperature flue gas that self-fluidized type room 120 is discharged enters with the tangential direction of separator body 210 After separator body 210, in separator body 210 inwall and lower aiutage 230 outer wall it Between rotate, under gravity, the flue dust in flue gas declines and by refeed line FL be delivered to flow Carry out second-time burning in changing room 120, and the flue gas after dedusting is finally by the top of lower aiutage 230 Portion's entrance is discharged lower discharge air separator 200 with direction from top to bottom and enters residual heat using device 300。

Residual heat using device 300 includes the removing for secondary ash disposal being sequentially communicated setting from bottom to top Ash room 310, for steam being heated into the superheater 320 of superheated steam, being used for cool water heating Become the economizer 330 of steam and for cold air being heated into the air preheater of hot-air 340.Wherein, the dedusting smoke inlet G1 that the outlet at bottom with lower aiutage 230 is connected is formed In a sidewall of dedusting chamber 310, the top of air preheater 340 is provided with and is connected by flue Low-temperature flue gas to chimney (not shown) exports G2, and a sidewall of air preheater 340 is provided with The cool air inlet C1 being connected with the first blower fan F1 by cold air pipeline (non-label), and another One sidewall is provided with the hot air outlet C2 being connected by hot-air pipeline HL with air compartment 130.

As a kind of alternative embodiments, flue GL is in lower discharge air separator 200 and remaining Between heat utilization device 300, there are backflow flue gas pipeline RL, backflow flue gas pipeline RL and heat in branch Air line HL is connected and is provided with blender 400, meanwhile, backflow flue gas pipeline in junction Upper the first valve V1 being provided with regulatable return-flow flue gas flow at neighbouring blender 400 of RL, heat At neighbouring blender 400, the second valve of scalable hot air flowrate it also is provided with on air line HL Door V2.Thus, account for the 15% of amount of flue gas emission, temperature about 800 degrees Celsius, oxygen content about 5% Heat smoke and temperature about 200 degrees Celsius, oxygen content about 21% hot-air at blender 400 Middle formation temperature about 500 degrees Celsius, the gaseous mixture of oxygen content about 13%.

As it is shown on figure 3, as another kind of alternative embodiments, blender 400 includes blender Body 410, be located at blender body 410 one end hot air inlet 420, be located at blender this The heat smoke entrance 430 of body 410 side, it is located at the gas mixing chamber within blender body 410 440 and be located at the mixed gas outlet 450 of the other end of blender body, wherein, gas mixes In chamber 440, neighbouring mixed gas outlet 450 is provided with rotary blade 460, the setting of rotary blade 460 It is possible not only to make the more uniform of heat smoke and hot-air mixing, it is also possible to eliminate self-heating cigarette Mars in gas, it is ensured that safety.

Continue back at Fig. 1, as another alternative embodiments, mixing from blender 400 Close gas to be delivered in the airduct 500 being connected with air compartment 130 by the second blower fan F2.Airduct 500 Including airduct body (non-label), it is located at the gaseous mixture entrance 501 of airduct body one end, is located at wind Wind chamber 502 within tube body, be located at the other end of airduct body mixed gas outlet (non-label), And the first homogenizing plate group that neighbouring mixed gas outlet is arranged in wind chamber 502, the first homogenizing plate group Three the first homogenizing plates 510 equidistantly arranged including level from top to bottom, thus utilize these three Mixed gas outlet is separated into four first shuntings connected respectively with air compartment 130 by one homogenizing plate 510 Passage 515.

As another alternative embodiments, in air compartment 130, it is provided with the second homogenizing plate group, second Homogenizing plate group include the lower surface interval vertical from air distribution plate 140 downwardly extend and equidistantly arrange three Individual second homogenizing plate, the development length of three the second homogenizing plates is incremented by, i.e. along the direction away from airduct With from the end away from airduct to three second homogenizing plates in the direction of neighbouring airduct respectively correspondingly Concordant with the horizontal direction of three the first homogenizing plates from bottom to top, thus in air compartment, it is separated out four Second split channel of individual connection corresponding with each first split channel respectively, it is ensured that gaseous mixture is equal Spray in fluidising chamber evenly.

Thus, when screw feeder 900, coal dust is entered by the coal dust arranged on the sidewall of fluidising chamber After mouth (not shown) is burnt in being delivered to fluidising chamber 120, the heat smoke of generation is with fume pipe Road GL enters in lower discharge air separator 200 to be separated by the flue dust in flue gas, after separation Flue dust carries out second-time burning in being delivered to fluidising chamber 120 by refeed line FL, and the cigarette after dedusting Gas then discharges lower discharge air separator by the top entry of lower aiutage 230 with direction from top to bottom 200 and enter residual heat using device 300, the flue gas in residual heat using device 300, after dedusting After sequentially passing through dedusting chamber 310, superheater 320, economizer 330 and air preheater 340, It is cooled to the dedusting flue gas of 20 degrees centigrade will pass through chimney and be expelled in atmospheric environment.And Air preheater 340 carries out the hot-air of heat exchange with heat smoke then by hot-air pipeline HL It is delivered in blender 400, in blender 400, passes through back from lower discharge air separator 200 Stream flue gas pipeline RL conveying account for the 15% of amount of flue gas emission, temperature about 800 degrees Celsius, oxygen-containing The heat smoke of amount about 5% mixes shape with temperature about 200 degrees Celsius, the hot-air of oxygen content about 21% Become temperature about 500 degrees Celsius, the gaseous mixture of oxygen content about 13%, be delivered to wind by airduct 500 Behind room 130, then it is interior for fluidized bed combustion coal dust to enter fluidising chamber 120 by blast cap 150, thus Realize recycling of energy.

Although described preferred implementation of the present utility model in detail at this, it is to be understood that this Utility model is not limited to the concrete structure describing in detail here and illustrating, without departing from this practicality May be effected by one skilled in the art in the case of novel spirit and scope other modification and Variant.For example, it is possible to be not provided with the residual heat using device of multi-layer, and only adopt in flue Use air preheater preheated air.

Claims (8)

1. a recirculating fluidized bed blast cap, recirculating fluidized bed include fluid bed body, be located at described Fluid bed body interior and described fluid bed body interior is divided into fluidising chamber above and The air distribution plate being positioned at the air compartment of lower section and several blast caps being arranged on described air distribution plate, its It is characterised by: described blast cap includes inner tube, is nested with at the outer tube outside said inner tube and from described The sidewall spacers of outer tube at least two discharge pipes that are downward-sloping and that connect with described outer tube, institute State inner tube to upwardly extend also around the air inlet on described air distribution plate from the upper surface of described air distribution plate And top closure, the diapire of described outer tube is connected to outer wall and the roof of described outer tube of said inner tube Being positioned at the top on the top of said inner tube, said inner tube is positioned at the tube wall of described outer tube and is provided with Several air holes.

2. recirculating fluidized bed blast cap as claimed in claim 1, it is characterised in that said inner tube Be positioned at the pipeline section of described outer tube a length of said inner tube length 2 to six/3rds/ Five, distance is said inner tube length ten between top and the roof of described outer tube of said inner tube 1/1 mono-to five.

3. recirculating fluidized bed blast cap as claimed in claim 2, it is characterised in that described outer tube Diapire and the upper surface of described air distribution plate between distance is said inner tube length 1/6th Distance to 1/3rd, between end and the upper surface of described air distribution plate of each described discharge pipe For said inner tube length 1/1st to three/6th.

4. recirculating fluidized bed blast cap as claimed in claim 3, it is characterised in that described outer tube Two times to five times of diameter of a diameter of said inner tube, a diameter of said inner tube of described air holes / to three/10th of diameter.

5. recirculating fluidized bed blast cap as claimed in claim 1, it is characterised in that each described Angle between discharge pipe and the central axis of said inner tube is set as 30～60 degree.

6. the recirculating fluidized bed blast cap as according to any one of Claims 1 to 5, its feature exists In, described at least two discharge pipes include isometric three arranged at equal intervals around described outer tube wall Individual discharge pipe, the diameter of a diameter of described outer tube of the end place circumference of described three discharge pipes Two times to five times.

7. the recirculating fluidized bed blast cap as according to any one of Claims 1 to 5, its feature exists In, the bottom of said inner tube is by welding or the threaded upper surface being fixed on described air distribution plate.

8. the recirculating fluidized bed blast cap as according to any one of Claims 1 to 5, its feature exists It is that array-like is distributed in said inner tube and is positioned at the tube wall of described outer tube in, several air holes described On.