Combination device for full combustion of domestic waste in pre-combustion furnace of cement kiln

Abstract

The application discloses a combined device for full combustion of domestic waste in a pre-combustion furnace in cement kiln collaborative disposal, which comprises a shell, a drying cavity and a combustion cavity are communicated and arranged in the shell in an up-down mode, the combustion cavity is communicated with a decomposing furnace through a combustion furnace, a feeding hopper is arranged on the shell and penetrates into the drying cavity, and an air inlet cylinder is further arranged on the obliquely upper part of the shell and penetrates into the drying cavity. Compared with the prior art, the material falling from the feeding hopper is blown into the three times of air from the air inlet cylinder and is turned back from the sawtooth surface and the inclined surface for multiple times, so that the material can be fully dried and combusted, the accumulation of the non-combustible material is avoided, the slope blockage is effectively prevented, and the pretreatment cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of cement kiln co-processing of municipal solid waste technology, specifically a combined device for co-processing municipal solid waste in a cement kiln with complete combustion in a pre-combustion furnace. Background Technology

[0002] The method of co-processing municipal solid waste in cement kilns has developed rapidly in recent years and has become an important method for municipal solid waste disposal, achieving certain results. Currently, there are two methods for co-processing municipal solid waste in cement kilns. The first involves incinerating municipal solid waste in a waste incinerator without pretreatment, with the resulting flue gas entering the cement kiln system and the slag being disposed of separately. This method has low processing capacity and affects the production capacity of cement clinker. The second method involves pre-treating municipal solid waste and separating it into undersize (such as slag, bricks, etc.) and oversize (such as plastics, paper, rubber, etc.). Based on the physical and chemical properties of each component, different disposal methods are applied in the cement production system. Undersize is used as a partial substitute raw material in cement production and enters the feed mill, while oversize is mechanically crushed and then transported to the kiln tail decomposition furnace for pyrolysis and incineration. Currently, this method has become the main method for co-processing municipal solid waste in cement kilns, but it also has limitations.

[0003] The screen residue after pretreatment of municipal solid waste still contains a certain amount of moisture. Direct combustion in the decomposition furnace will affect the thermal stability of the cement kiln. It is necessary to burn the municipal solid waste as completely as possible before it enters the decomposition furnace to reduce the impact on the cement kiln system and increase the amount of municipal solid waste that can be disposed of.

[0004] Therefore, it is necessary to provide a combined device for co-processing municipal solid waste in cement kilns and ensuring its complete combustion in a pre-combustion furnace, in order to solve the problems mentioned in the background art. Summary of the Invention

[0005] To achieve the above objectives, the present invention provides the following technical solution: a combined device for co-processing municipal solid waste in a cement kiln and fully combusting it in a pre-combustion furnace, comprising an outer shell, wherein a drying chamber and a combustion chamber are distributed vertically within the outer shell, the combustion chamber is connected to a decomposition furnace via a combustion chamber, a feed hopper penetrating into the drying chamber is provided above the outer shell, and an air inlet duct penetrating into the drying chamber is also provided diagonally above the outer shell.

[0006] Furthermore, as a preferred embodiment, an opening and closing door capable of horizontal movement controlled by a cylinder is provided between the drying chamber and the combustion chamber.

[0007] Furthermore, as a preferred embodiment, the side of the drying chamber near the air inlet is sloped.

[0008] Furthermore, as a preferred embodiment, the side of the drying chamber near the feed hopper has a serrated surface.

[0009] Furthermore, as a preferred embodiment, the feed hopper is rotatably provided with a feed turntable, which is composed of multiple circumferentially distributed plates and can seal the connection between the feed hopper and the drying chamber.

[0010] Furthermore, as a preferred embodiment, a feed baffle is provided below the feed turntable in the drying chamber to guide the material to fall away from the air inlet duct.

[0011] Furthermore, preferably, the middle part of the air inlet duct is rotatably connected to the outer casing.

[0012] Furthermore, preferably, the combustion chamber and the combustion chamber are equipped with multiple air cannons below.

[0013] Furthermore, as a preferred embodiment, there is a certain gap between the outer wall of the drying chamber and the inner wall of the outer shell, the rotating shaft of the feeding plate passes through the gap and is fixed with a cam, one end of the cam is hinged to a feeding connecting rod, the other end of the feeding connecting rod is hinged to a hinge, and the hinge is fixed to a piston rod inside the cylinder.

[0014] Furthermore, as a preferred embodiment, there is a certain gap between the outer wall of the drying chamber and the inner wall of the outer shell, the rotating shaft of the air inlet duct passes through the gap and is fixed with a rotating rod, one end of the rotating rod is hinged to an air inlet connecting rod, the other end of the air inlet connecting rod is hinged to a hinge, and the hinge is fixed to a piston rod inside the cylinder.

[0015] Compared with the prior art, the beneficial effects of the present invention are:

[0016] In this invention, the pre-combustion furnace is divided into three stages: a drying chamber, a combustion chamber, and a combustion chamber. This increases the residence time of the material at high temperatures, ensuring complete combustion and reducing the impact on the clinker section combustion system of the cement kiln. Low-pressure air cannons cause slight tumbling of the material, promoting complete combustion while preventing the accumulation of difficult-to-burn materials and effectively preventing slope blockage. The air cannons also increase the oxygen content required for combustion, providing the necessary conditions for complete combustion. This reduces pretreatment costs. The moisture content requirements for the oversize material after municipal solid waste pretreatment are no longer stringent.

[0017] In this invention, the material falling from the feed hopper collides with the tertiary air blown in by the air inlet duct and repeatedly bounces back from the tertiary surface and the inclined surface, increasing the time the material floats in the drying chamber and ensuring sufficient contact between the material and the tertiary air, thus significantly reducing the material's moisture content. The reciprocating motion of the cylinder drives the feed plate to rotate continuously, so that when the material in the drying chamber falls into the combustion chamber, the material in the feed hopper also falls into the drying chamber. Simultaneously, when the door is closed, the air inlet duct rotates towards the tertiary surface, allowing the tertiary air to guide the material back and forth between the tertiary surface and the inclined surface. And when the door is open, the air inlet duct rotates towards the inclined surface, allowing the tertiary air to guide the material to quickly fall into the combustion chamber along the inclined surface, preventing mixing with the new material falling from the feed hopper. Attached Figure Description

[0018] Figure 1 A schematic diagram of a combined device for co-processing municipal solid waste in a cement kiln and ensuring its complete combustion in a pre-combustion furnace;

[0019] Figure 2 This is a schematic diagram of the cross-section of the outer shell;

[0020] Figure 3 This is a schematic diagram of the structure of the sidewall between the drying chamber and the outer shell;

[0021] In the diagram: 1. Outer shell; 11. Drying chamber; 12. Combustion chamber; 13. Combustion tube; 14. Inclined surface; 15. Serrated surface; 16. Air cannon; 2. Feed hopper; 21. Feeding turntable; 22. Feeding baffle; 23. Cam; 24. Feeding connecting rod; 3. Air inlet duct; 31. Rotating rod; 32. Air inlet connecting rod; 4. Cylinder; 41. Opening and closing door; 42. Hinge; 5. Decomposition furnace. Detailed Implementation

[0022] Please see Figure 1 and Figure 2 In this embodiment of the invention, a combined device for co-processing municipal solid waste in a cement kiln and fully combusting it in a pre-combustion furnace includes an outer shell 1. A drying chamber 11 and a combustion chamber 12 are distributed vertically inside the outer shell 1. The combustion chamber 12 is connected to a decomposition furnace 5 through a combustion tube 13. A feed hopper 2 is provided above the outer shell 1, which extends into the drying chamber 11. An air inlet duct 3 is also provided diagonally above the outer shell 1, which extends into the drying chamber 11.

[0023] In this embodiment, an opening and closing door 41 that can be controlled to move horizontally by a cylinder 4 is provided between the drying chamber 11 and the combustion chamber 12, so that the residence time of the material in the drying chamber 11 can be controlled by the cycle time of the cylinder 4, thereby controlling the moisture content of the material in the drying section.

[0024] The drying chamber 11 has an inclined surface 14 on the side near the air inlet duct 3. The inclined surface 14 can guide the material falling from the feed hopper 2 to gather on the opening and closing door 41 so that the material can fall completely into the combustion chamber 12 when the opening and closing door 41 is opened.

[0025] In this embodiment, the side of the drying chamber 11 closest to the feed hopper 2 is a serrated surface 15, which causes the material falling from the feed hopper 2 to collide with the tertiary air blown in by the air inlet duct 3 and to bounce back from the serrated surface 15 and the inclined surface 14 multiple times, thereby increasing the time the material floats in the drying chamber 11, allowing the material to fully contact the tertiary air, and thus fully reducing the moisture content of the material.

[0026] In this embodiment, a feed turntable 21 is rotatably provided inside the feed hopper 2. The feed turntable 21 is composed of multiple circumferentially distributed plates and can seal the through-hole between the feed hopper 2 and the drying chamber 11. By rotating the feed turntable 21, the material in the feed hopper 2 can be quantitatively dropped into the drying chamber 11, and the backflow of air in the drying chamber 11 can be prevented.

[0027] In this embodiment, a feed baffle 22 is provided below the feed turntable 21 in the drying chamber 11 to guide the material to fall away from the air inlet duct 3. That is, the material falls from the feed baffle 22 along the direction of the air inlet duct 3, and can be deflected as much as possible in the sawtooth surface 15 and the inclined surface 14 by the guidance of the tertiary air blown in by the air inlet duct 3.

[0028] In this embodiment, the middle part of the air inlet duct 3 is rotatably connected to the outer casing 1. By rotating the air inlet duct 3, the blowing angle of the tertiary air can be changed, thereby altering its guiding path for the material.

[0029] In this embodiment, multiple air cannons 16 are provided below the combustion chamber 12 and the combustion chamber 13. The material falling into the combustion chamber 12 is continuously replenished with air and tumbled by the low-pressure blowing of the air cannons 16, which can promote the complete combustion of the material. The unburned material continues to burn in the burnout section.

[0030] In this embodiment, there is a certain gap between the outer wall of the drying chamber 11 and the inner wall of the outer shell 1. The rotating shaft of the feeding turntable 21 passes through this gap and is fixed with a cam 23. One end of the cam 23 is hinged to a feeding connecting rod 24, and the other end of the feeding connecting rod 24 is hinged to a hinge 42. The hinge 42 is fixed to a piston rod inside the cylinder 4. That is, the reciprocating motion of the cylinder 4 can drive the feeding turntable 21 to rotate continuously, so that when the material in the drying chamber 11 falls into the combustion chamber 12, the material in the feeding hopper 2 also falls into the drying chamber 11.

[0031] In this embodiment, there is a certain gap between the outer wall of the drying chamber 11 and the inner wall of the outer shell 1. The rotating shaft of the air inlet duct 3 passes through this gap and is fixed with a rotating rod 31. One end of the rotating rod 31 is hinged to an air inlet connecting rod 32, and the other end of the air inlet connecting rod 32 is hinged to a hinge 42. The hinge 42 is fixed to a piston rod inside the cylinder 4. That is, the reciprocating motion of the cylinder 4 can drive the air inlet duct 3 to rotate reciprocally. When the opening and closing door 41 is closed, the air inlet duct 3 rotates towards the serrated surface 15 so that the tertiary air guides the material to collide and bounce back in the serrated surface 15 and the inclined surface 14. When the opening and closing door 41 is open, the air inlet duct 3 rotates towards the inclined surface 14 so that the tertiary air guides the material to fall quickly into the combustion chamber 12 along the inclined surface 14, avoiding mixing with the new material falling from the feed hopper 2.

[0032] In practice,

[0033] S1. The pretreatment system separates municipal solid waste into oversize and undersize materials. The main processes of the municipal solid waste pretreatment system include crushing, screening, air separation and dewatering. The undersize material obtained after air separation is sent to the raw material mill and used as cement raw material in production. The oversize material obtained is continuously fed into the feed hopper 2 after compression and dewatering.

[0034] S2. High-temperature tertiary air from the clinker calcination system is introduced through the air inlet duct 3 as combustion air, and the temperature can reach 700-900℃.

[0035] S3. The material falling from the feed hopper 2 into the drying chamber collides with the tertiary air blown in by the air inlet duct 3 and is repeatedly collided and folded back from the tertiary airlet duct 15 and the inclined surface 14 to increase the floating time of the material in the drying chamber 11, so that the material can fully contact the tertiary air and fully reduce the moisture content of the material. After the material stays in the drying chamber 11 for 3-5 minutes, it all falls onto the opening and closing door 41.

[0036] S4. The cylinder 4 opens and closes the door 41 once, which lasts for 1-2 seconds. During this process, the air inlet duct 3 rotates back and forth once, blowing the dried material into the combustion chamber 12 along the inclined surface 14. The feed plate 21 rotates once, causing the material in the feed hopper 2 to fall into the drying chamber 11 along the feed baffle 22.

[0037] S5. The combustion chamber 12 is a 50° inclined slope. The combustion chamber 12 is equipped with two layers of air cannons 16, two in each layer. The air cannons 16 are arranged perpendicular to the slope. Two air cannons (pressure 0.2-0.3 MPa) are arranged in the middle of the slope to prevent material accumulation on the slope. The other two air cannons (pressure 0.3-0.4 MPa) are arranged in the lower quarter of the slope to make the material fall evenly into the combustion chamber 13. The material on the slope is slightly tumbled under the low pressure of the air cannons 16. After combustion and decomposition, it falls into the combustion chamber 13 to continue burning.

[0038] S6. The air cannons 16 of the combustion chamber 13 consist of three sets of air cannons, two in each set, arranged on both sides and in the middle respectively. The angle of the air cannons is 30° and the pressure of each cannon is 0.4-0.5 MPa. The ash of the combustion chamber 13 is carried into the decomposition furnace 5 under the action of the corresponding air cannons 16. The unburned material continues to burn after falling into the combustion chamber 13, and the burned material is blown into the decomposition furnace 5.

[0039] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A combined device for full combustion of domestic waste in a precalciner for cement kiln co-processing of domestic waste, comprising a housing (1), characterized in that, The shell (1) has a drying cavity (11) and a combustion cavity (12) in communication vertically, the combustion cavity (12) is communicated to the decomposition furnace (5) through a burner (13), the shell (1) is provided with a feeding hopper (2) penetrating into the drying cavity (11) above, and the shell (1) is further provided with an air inlet cylinder (3) penetrating into the drying cavity (11) obliquely above; The side of the drying cavity (11) close to the feeding hopper (2) is a sawtooth surface (15); The feeding hopper (2) is rotatably provided with a feeding rotating plate (21), the feeding rotating plate (21) is composed of a plurality of circumferentially distributed plates, and the feeding hopper (2) and the penetration opening of the drying cavity (11) can be sealed by the feeding rotating plate (21); The outer wall of the drying cavity (11) and the inner wall of the shell (1) have a gap, the rotating shaft of the feeding rotating plate (21) penetrates into the gap, and a cam (23) is fixed on the rotating shaft, one end of the cam (23) is hingedly connected with a feeding connecting rod (24), the other end of the feeding connecting rod (24) is hingedly connected to a hinge (42), and the hinge (42) is fixed to a piston rod in a cylinder (4); The rotating shaft of the air inlet cylinder (3) penetrates into the gap, and a rotating rod (31) is fixed on the rotating shaft, one end of the rotating rod (31) is hingedly connected with an air inlet connecting rod (32), the other end of the air inlet connecting rod (32) is hingedly connected to the hinge (42), and the hinge (42) is fixed to the piston rod in the cylinder (4).

2. The combined device for full combustion of domestic waste in a precalciner of a cement kiln according to claim 1, characterized in that, The drying cavity (11) and the combustion cavity (12) are provided with an opening and closing door (41) capable of being controlled to move horizontally by the cylinder (4).

3. The combined device for sufficient combustion of domestic waste in a precalciner of a cement kiln for its co-processing according to claim 1, characterized in that, The side of the drying cavity (11) close to the air inlet cylinder (3) is an inclined surface (14).

4. The combined device for full combustion of domestic waste in a precalciner of a cement kiln according to claim 1, characterized in that, The lower portion of the feeding rotating plate (21) in the drying cavity (11) is provided with a feeding baffle (22) for guiding the material to fall away from the air inlet cylinder (3).

5. The combined device for full combustion of domestic waste in a precalciner of a cement kiln according to claim 1, characterized in that, The middle portion of the air inlet cylinder (3) is rotatably connected to the shell (1).

6. The combined device for full combustion of domestic waste in a precalciner of a cement kiln according to claim 1, characterized in that, The combustion cavity (12) and the burner (13) are provided with a plurality of air cannons (16) below.

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