A feeding and slagging structure and method for a fluidized bed boiler suitable for biomass and garbage incineration

Abstract

The present invention provides a feeding and slag discharge structure and method for a fluidized bed boiler suitable for biomass and garbage incineration, comprising a silo, a screw feeder, a slag discharge pipe and a cooling and screening device, wherein the discharge port of the silo is connected to the feed port of the screw feeder, and the discharge port of the screw feeder is connected to the feed port opened on the wall of the fluidized bed furnace; a broadcasting wind is provided at the discharge port of the screw feeder; the slag discharge pipe is arranged at the feed port at the bottom of the fluidized bed furnace, and passes through the wind chamber arranged below the furnace and is placed on the outside of the furnace; the slag discharge port of the slag discharge pipe is connected to the feed port of the cooling and screening device, and the screened material outlet of the cooling and screening device is connected to the feed port at the bottom of the furnace; the present invention has the advantages of uniform feeding, easy discharge of debris, recycling of bed materials, and long boiler operation cycle.

Description

Technical Field

[0001] The invention belongs to the technical field of biomass utilization and garbage disposal, and in particular relates to a feeding and slagging structure and method for a fluidized bed boiler suitable for biomass and garbage incineration. Background Art

[0002] Circulating fluidized bed boiler has wide fuel adaptability, high combustion efficiency, high efficiency desulfurization, NO X Fluidized bed boilers have many advantages such as low emissions, simple structure, and easy operation. In addition to conventional coal-fired applications, they are also widely used in biomass utilization, garbage disposal, etc. However, in actual applications, users of biomass boilers and garbage boilers cannot ensure stable feeding due to the complexity of fuels, and too many impurities in the fuel make slagging difficult, resulting in unstable combustion, short operating cycles, and easy backflow of flue gas.

[0003] The measures currently taken are basically based on considerations from the source of fuel, that is, in the process of fuel processing, multi-stage crushing, sorting, iron removal, and large block removal equipment are added. However, this still cannot completely solve the problems of slag discharge and short operating cycle. The furnace must be shut down for bed material replacement every 1 to 2 months. Summary of the invention

[0004] The purpose of the present invention is to provide a fluidized bed boiler feeding and slagging structure and method suitable for biomass and garbage incineration, which solves the problems of unstable combustion, short operating cycle, easy backflow of flue gas and the like caused by the difficulty of slagging in existing circulating fluidized bed boilers.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] The present invention provides a fluidized bed boiler feeding and slag discharge structure suitable for biomass and garbage incineration, comprising a silo, a screw feeder, a slag discharge pipe and a cooling and screening device, wherein the discharge port of the silo is connected to the feed port of the screw feeder, and the discharge port of the screw feeder is connected to the feed port opened on the wall of the fluidized bed furnace; a broadcasting wind is provided at the discharge port of the screw feeder; the slag discharge pipe is arranged at a position below the feed port at the bottom of the fluidized bed furnace, and passes through a wind chamber arranged below the furnace and is placed on the outside of the furnace; the slag discharge port of the slag discharge pipe is connected to the feed port of the cooling and screening device, and the screened material outlet of the cooling and screening device is connected to the feed port at the bottom of the furnace.

[0007] Preferably, the screw feeder is arranged in an inclined upward structure.

[0008] Preferably, a material dispenser is arranged in the silo.

[0009] Preferably, a material protection eaves is provided above the material feed port opened on the furnace wall.

[0010] Preferably, the screw feeder is a shaftless screw feeder.

[0011] Preferably, a slag discharge valve and an air cannon are provided at the slag discharge port of the slag drop pipe, and the air cannon is placed between the slag discharge valve and the furnace.

[0012] A feeding and slagging method for a fluidized bed boiler suitable for biomass and waste incineration, based on the feeding and slagging structure of a fluidized bed boiler suitable for biomass and waste incineration, comprises the following steps:

[0013] The fuel in the silo is pushed into the furnace by the screw feeder;

[0014] After the fuel enters the furnace, the lighter materials are blown to the middle of the furnace under the action of the spreading wind, and the heavier impurities fall to the slag pipe below and are discharged out of the furnace;

[0015] After the slag is discharged, under the action of cooling and screening devices, the underscreen material can be sent back to the furnace as supplementary bed material, and the overscreen material can be comprehensively utilized.

[0016] Preferably, when the slag discharge from the slag falling pipe is not smooth, turn on the air cannon and use the air cannon to loosen the bottom slag in the slag falling pipe to facilitate the discharge of the bottom slag;

[0017] When the strength is not enough, close the slag discharge valve, open the air cannon, and use the air cannon to loosen the bottom slag in the slag drop pipe. After loosening, open the slag discharge valve to discharge the bottom slag.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The present invention provides a feeding and slag discharge structure and method for a fluidized bed boiler suitable for biomass and garbage incineration. A feeding air is arranged at the lower part of the feeding port, which simultaneously plays the role of feeding and separating debris, and the material distribution uniformity is better; a slag discharge port is arranged on the bed surface or the front wall below the corresponding position of the feeding port. Under the action of the feeding air, lighter materials are thrown to the rear wall of the furnace, and heavier debris falls against the front wall, so that the debris is easier to discharge; in addition, because the slag discharge port is arranged on the front wall, it is not easy to discharge the circulating ash, so that the boiler operation is more stable and the operation cycle is longer; a cooling and screening device is arranged at the outlet of the slag discharge pipe, and the screened material can be sent back to the furnace as supplementary bed material, and the screened material can be comprehensively utilized. Therefore, the present invention has the advantages of uniform feeding, easy discharge of debris, recycling of bed material, and long boiler operation cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of the present invention. DETAILED DESCRIPTION

[0021] The present invention will be further described in detail below in conjunction with the accompanying drawings.

[0022] like Figure 1 As shown, the present invention provides a feeding and slag discharge structure for a fluidized bed boiler suitable for biomass and garbage incineration, comprising an air cannon 1, a wind chamber 2, a furnace 3, a return port 4, a return device 5, a separator 6, a smoke outlet 7, a material protection eaves 8, a silo 9, a material dispenser 10, a screw feeder 11, a material broadcasting wind 12, a slag drop pipe 13, a slag discharge valve 14 and a cooling and screening device 15, wherein a wind chamber 2 is arranged below the furnace 3 of the fluidized bed boiler; the smoke outlet of the furnace 3 is connected to the separator 6, the gas outlet of the separator 6 is connected to the smoke outlet 7, the circulating ash outlet of the separator 6 is connected to the feeding port of the return device 5; the circulating ash outlet of the return port 5 is connected to the return port 4 opened on the furnace 3.

[0023] A feed port is provided on the wall of the furnace 3 , and a screw feeder 11 is connected to the feed port; the feed port of the screw feeder 11 is connected to the discharge port of the silo 9 .

[0024] A slag dropping pipe 13 is provided at the bottom of the furnace 3 near the lower part of the feed port, and the slag dropping pipe 13 passes through the wind chamber 2 and is placed outside the furnace 3; this structure facilitates the discharge of heavier impurities in the fuel, and at the same time, because it is far away from the return port 4, it can prevent the discharge of return ash.

[0025] The slag discharge port of the slag drop pipe 13 is connected to a cooling and screening device 15 ; the screened material outlet of the cooling and screening device 15 is connected to an external device, and the screened material outlet of the cooling and screening device 15 is connected to a feed port opened at the bottom of the furnace 3 .

[0026] A slag discharge valve 14 and an air cannon 1 are provided at the slag discharge port of the slag dropping pipe 13, wherein the air cannon 1 is placed between the slag discharge valve 14 and the furnace; when the slag discharge is not smooth, the air cannon 1 and the slag discharge valve 14 can be used to loosen the bottom slag in the pipe to facilitate the discharge of the bottom slag.

[0027] A material protection eave 8 is provided at the feed inlet opened on the wall of the furnace 3 to prevent the wall flow from scouring the fuel inlet and reduce the resistance of feeding into the furnace.

[0028] A material dispenser 10 is provided in the inner cavity of the silo 9 to prevent material bridging.

[0029] The screw feeder 11 is arranged in an oblique upward structure; a broadcasting wind 12 is provided at the discharge port of the screw feeder 11. Under the action of the broadcasting wind 12, lighter materials fly to the center of the furnace, and heavier impurities fall to the slag dropping pipe 13; the screw feeder is inclined to feed, and the feed port can be arranged at a higher position in the furnace, and the furnace pressure is relatively small.

[0030] The screw feeder 11 is preferably a shaftless screw type to avoid material entanglement.

[0031] The working principle of the present invention is:

[0032] The fuel in the silo 9 normally falls to the screw feeder 11 under the action of the material distributor 10; the screw feeder 11 is arranged obliquely, and the fuel enters the furnace 3 under the push of the screw feeder 11;

[0033] After the fuel is put into the furnace, under the action of the material-broadening wind 12, the lighter materials are blown to the middle of the furnace 3, and the heavier impurities fall to the slag dropping pipe 13 below and are discharged out of the furnace.

[0034] After the slag is discharged, under the action of the cooling and screening device 15, the undersize material can be sent back to the furnace 3 as supplementary bed material, and the oversize material can be comprehensively utilized.

[0035] When the slag dropping pipe 13 is not able to discharge slag smoothly, the air cannon 1 is turned on to loosen the bottom slag in the slag dropping pipe 13 by using the air cannon 1 to facilitate the discharge of the bottom slag.

[0036] When the strength is insufficient, close the slag discharge valve 14, open the air cannon 1, and use the air cannon 1 to loosen the bottom slag in the slag falling pipe 13. After loosening, open the slag discharge valve 14 to discharge the bottom slag.

[0037] The invention can be used as a new boiler design or as an existing boiler modification. The invention has the advantages of no bridging, uniform feeding, no backflow of smoke, easy discharge of debris, recycling of bed materials, and long boiler operation period.

[0038] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. Any changes and improvements made according to the scope of application of the present invention should still fall within the scope of the present invention.

Claims

1. A feeding and slagging structure for a fluidized bed boiler suitable for biomass and waste incineration, characterized in that: The invention comprises a silo (9), a screw feeder (11), a slag dropping pipe (13) and a cooling and screening device (15), wherein the discharge port of the silo (9) is connected to the feed port of the screw feeder (11), and the discharge port of the screw feeder (11) is connected to the feed port opened on the wall of the fluidized bed furnace (3); a material spreading air (12) is provided at the discharge port of the screw feeder (11); the slag dropping pipe (13) is arranged at a position below the feed port at the bottom of the fluidized bed furnace (3) and passes through a wind chamber (2) arranged below the furnace (3) and is placed outside the furnace (3); the slag discharge port of the slag dropping pipe (13) is connected to the feed port of the cooling and screening device (15), and the screened material outlet of the cooling and screening device (15) is connected to the feed port at the bottom of the furnace (3); The screw feeder (11) is arranged in an inclined upward structure; A material protection eave (8) is provided above the material inlet opened on the wall of the furnace (3); A slag discharge valve (14) and an air cannon (1) are provided at the slag discharge port of the slag dropping pipe (13); the air cannon (1) is placed between the slag discharge valve (14) and the furnace.

2. A feeding and slag discharge structure for a fluidized bed boiler suitable for biomass and waste incineration according to claim 1, characterized in that: A material dispenser (10) is arranged in the material bin (9).

3. The feeding and slagging structure of a fluidized bed boiler suitable for biomass and waste incineration according to claim 1, characterized in that: The screw feeder (11) is a shaftless screw type screw feeder.

4. A feeding and slagging method for a fluidized bed boiler suitable for biomass and waste incineration, characterized in that: A feeding and slagging structure for a fluidized bed boiler suitable for biomass and waste incineration according to any one of claims 1 to 3 comprises the following steps: The fuel in the silo (9) enters the furnace (3) under the push of the screw feeder (11); After the fuel is put into the furnace, under the action of the material-bearing wind (12), the lighter materials are blown to the middle of the furnace (3), and the heavier impurities fall to the slag dropping pipe (13) below and are discharged out of the furnace; After the slag is discharged, under the action of the cooling and screening device (15), the underscreen material can be sent back to the furnace (3) as supplementary bed material, and the overscreen material can be comprehensively utilized.

5. A feeding and slagging method for a fluidized bed boiler suitable for biomass and waste incineration according to claim 4, characterized in that: When the slag discharge from the slag dropping pipe (13) is not smooth, the air cannon (1) is turned on, and the bottom slag in the slag dropping pipe (13) is loosened by using the air cannon (1) to facilitate the discharge of the bottom slag; When the strength is insufficient, the slag discharge valve (14) is closed, the air cannon (1) is opened, and the bottom slag in the slag drop pipe (13) is loosened by the air cannon (1). After the slag is loosened, the slag discharge valve (14) is opened to discharge the bottom slag.

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