Alternative fuel and fossil fuel integrated combustion system for cement kiln

Abstract

The invention discloses an alternative fuel and fossil fuel integrated combustion system for a cement kiln, and relates to the technical field of cement kiln combustion, and the alternative fuel and fossil fuel integrated combustion system comprises an alternative fuel drying assembly, a pulverized coal injection assembly, a combustion assembly, a feeding assembly and an air blowing assembly. According to the alternative fuel and fossil fuel integrated combustion system for the cement kiln, the alternative fuel conveying pipe, the pulverized coal injection pipe and the ignition pipe are arranged in the main pipeline, so that integrated supply of alternative fuel and fossil fuel is achieved, and more comprehensive energy supply conditions are provided for production of the cement kiln; axial air and rotational flow air are used for achieving uniform mixing of alternative fuel and fossil fuel, stable and reliable heat supply is provided for cement kiln production, the pulverized coal diffusion effect is further improved through the arrangement of the annular pulverized coal channel, and further guarantee is provided for rapid rising of the temperature in the cement kiln and uniformity of the temperature.

Description

Technical Field

[0001] The invention relates to the technical field of cement kiln combustion, and in particular to an alternative fuel and fossil fuel integrated combustion system for a cement kiln. Background Art

[0002] Traditional cement production burners can only use fossil fuels or alternative fuels, which has great limitations on cement production. In addition, when alternative fuels are used at the kiln head in cement production, especially biomass fuels and waste fuels, the following disadvantages may occur due to the influence of the moisture content of the alternative fuels: Reduced combustion efficiency: high moisture content absorbs heat from the combustion process and is used for its own evaporation, thereby reducing the heat available for effective combustion, causing the combustion temperature to drop, the combustion speed to slow down, and the combustion efficiency to decrease; Increased energy consumption: In order to evaporate the water in the fuel, additional energy is consumed, which increases the energy consumption cost of the entire production process; Affects the temperature distribution in the kiln. Uneven evaporation of water may lead to large local temperature differences in the kiln, affecting the stability and consistency of product quality; Increased emissions. Incomplete combustion may lead to increased emissions of pollutants such as carbon monoxide and nitrogen oxides, which will put more pressure on the environment; Reduce equipment service life, unstable combustion efficiency and temperature fluctuations may cause thermal shock to kiln equipment, accelerate equipment wear and aging, and shorten its service life.

[0003] Based on the search of the above information, it can be seen that there is an urgent need for a two-in-one burner that is compatible with both fossil fuels and alternative fuels. Summary of the invention

[0004] In view of the deficiencies of the prior art, the present invention provides an alternative fuel and fossil fuel integrated combustion system for a cement kiln, which solves the problems raised in the above background technology.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions: an alternative fuel and fossil fuel integrated combustion system for cement kilns, comprising an alternative fuel drying component, a coal powder injection component and a combustion component, wherein the output end of the alternative fuel drying component is provided with a feeding component, and the output ends of the feeding component and the coal powder injection component are both connected to the input end of the combustion component: The combustion assembly includes a main pipeline, one end of which is penetrated by and fixedly installed with a blowing assembly, one end of which is penetrated by an alternative fuel delivery pipe, a coal powder injection pipe and an ignition pipe, and the interior of the blowing assembly and the periphery of the alternative fuel delivery pipe, the coal powder injection pipe and the ignition pipe are filled with insulation material.

[0006] The present invention is further configured as follows: the alternative fuel drying assembly includes a protective shell, the tops of both sides of the protective shell are respectively connected with a hot air inlet pipe and a hot air outlet pipe, a drying chamber is fixedly installed inside the protective shell, an air passage is reserved between the outer wall of the drying chamber and the protective shell, the hot air inlet pipe and the hot air outlet pipe are both connected with the air passage, two groups of air passages are fixedly installed on the inner wall of the drying chamber, and both ends of the air passages are connected with the air passage; A driving motor is fixedly mounted on the top of the inner cavity of the drying bin via a mounting bracket, a stirring frame is fixedly mounted on the output end of the driving motor, and a discharge pipe is connected to the bottom of the protective shell.

[0007] The present invention is further configured as follows: the feeding assembly comprises a screw feeder and a first Roots blower, the screw feeder is arranged below the drying bin, and the feed port of the screw feeder is connected to the bottom end of the discharge pipe, the output end of the screw feeder is connected to the discharge pipe, the output end of the first Roots blower is connected to the first air guide pipe, and one end of the discharge pipe is connected to the first air guide pipe; One end of the first air guide pipe is in communication with one end of the alternative fuel delivery pipe.

[0008] The present invention is further configured as follows: the pulverized coal injection assembly comprises a second Roots blower and a pulverized coal conveyor, the output end of the second Roots blower is connected to a second air duct, and the output end of the pulverized coal conveyor is connected to the second air duct; One end of the second air guide pipe is communicated with one end of the coal powder injection pipe.

[0009] The present invention is further configured as follows: the blowing assembly comprises a single-end air sleeve and a blower, a single-end swirl air sleeve is further provided inside the single-end air sleeve, one end of the single-end air sleeve and the single-end swirl air sleeve are both provided with mounting holes, the other end of the single-end air sleeve is provided with a plurality of axial air holes at even intervals, one end of the single-end air sleeve is connected with an air inlet pipe, the other end of the single-end swirl air sleeve is provided with a plurality of swirl air holes at even intervals, one end of the single-end swirl air sleeve is connected with an air passage, one end of the air passage is welded and fixed inside the single-end air sleeve, and is provided in communication with the single-end air sleeve; The air inlet pipe is communicated with the output end of the blower through a pipeline.

[0010] The present invention is further configured such that the outer periphery of the single-end air sleeve is fixedly connected to the inner wall of the main pipeline.

[0011] The present invention is further configured as follows: the bottom of the coal powder injection pipe is connected to a diverter pipe, and an annular coal powder channel used in conjunction with the diverter pipe is spaced between the inner wall of the single-end air sleeve and the outer wall of the single-end swirl air sleeve.

[0012] The present invention is further configured as follows: one end of the alternative fuel delivery pipe, the coal powder injection pipe and the ignition pipe are all arranged through two mounting holes; The heat insulating material is filled in the interior of the single-end swirl air sleeve, and the heat insulating material is composed of one or more of rock wool, glass fiber and aerogel felt.

[0013] The present invention provides an alternative fuel and fossil fuel integrated combustion system for cement kilns. It has the following beneficial effects: (1) The present invention realizes the integrated supply of alternative fuels and fossil fuels by arranging alternative fuel delivery pipes, coal powder injection pipes and ignition pipes in the main pipeline, thereby providing more comprehensive energy supply conditions for cement kiln production. By arranging the blowing assembly, the alternative fuels and fossil fuels are evenly mixed by axial wind and swirl wind, thereby providing stable and reliable heat supply for cement kiln production. In addition, by arranging the annular coal powder channel, the coal powder diffusion effect is further improved, thereby providing further guarantee for the rapid increase of temperature and temperature uniformity in the cement kiln.

[0014] (2) The present invention can dry the alternative fuel by setting up an alternative fuel drying component, and can also cooperate with a screw feeder to realize the storage and convenient transportation of the alternative fuel. While being easy to use, the protection shell and the drying bin are set up to facilitate the maintenance and repair of the device. The drive motor and the stirring frame are set up to provide reliable protection for the drying of the alternative fuel in the drying bin. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the external structure of the present invention; Figure 2 It is a schematic diagram of the internal structure of the alternative fuel drying assembly of the present invention; Figure 3 A top view of the internal structure of the alternative fuel drying assembly of the present invention; Figure 4 is a cross-sectional view of a combustion assembly of the present invention; Figure 5 It is a schematic diagram of the connection of the coal powder injection pipe, the diverter pipe and the blowing assembly structure of the present invention; Figure 6 It is a structural schematic diagram of the blowing assembly of the present invention; Figure 7 This is a schematic diagram of the internal structure of the coal powder injection pipe of the present invention.

[0016] In the figure: 1. Alternative fuel drying assembly; 101. Protective housing; 102. Hot air inlet pipe; 103. Hot air outlet pipe; 104. Drying chamber; 105. Air passage; 106. Air passage; 107. Driving motor; 108. Stirring frame; 109. Discharging pipe; 2. Coal powder injection assembly; 201. Second Roots blower; 202. Coal powder conveyor; 203. Second air duct; 3. Combustion assembly; 301. Main pipeline; 302. Alternative fuel delivery pipe; 303. Coal powder injection pipe; 3031. Diverter pipe; 3032. Annular coal powder channel; 304. Ignition pipe; 305. Insulation material; 4. Feeding assembly; 401. Screw feeder; 402. First Roots blower; 403. First air guide pipe; 5. Blowing assembly; 501. Single-end air sleeve; 502. Blower; 503. Single-end swirl air sleeve; 504. Mounting hole; 505. Axial air hole; 506. Air inlet pipe; 507. Swirl air hole; 508. Air duct. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0018] See also Figure 1-7 The embodiment of the present invention provides the following technical solutions: an alternative fuel and fossil fuel integrated combustion system for a cement kiln, comprising an alternative fuel drying component 1, a coal powder injection component 2, a combustion component 3, a feeding component 4 and a blowing component 5, wherein, in order to realize the integration of alternative fuels and fossil fuels and provide a more comprehensive energy supply method for cement kiln production, the combustion component 3 comprises a main pipeline 301, the blowing component 5 passes through and is fixedly installed at one end inside the main pipeline 301, one end inside the blowing component 5 passes through an alternative fuel delivery pipe 302, a coal powder injection pipe 303 and an ignition pipe 304, the interior of the blowing component 5 and the outer periphery of the alternative fuel delivery pipe 302, the coal powder injection pipe 303 and the ignition pipe 304 are filled with a heat insulation material 305, and the heat insulation material 305 is composed of one or more of rock wool, glass fiber and aerogel felt.

[0019] It should be noted that an igniter is also provided on one side of the ignition tube 304 for igniting the ignitable gas passing through the ignition tube 304 .

[0020] As a preferred solution, in order to reduce the water content of the alternative fuel delivered to the combustion component 3, the alternative fuel drying component 1 includes a protective shell 101, and the tops of both sides of the protective shell 101 are respectively connected with a hot air inlet pipe 102 and a hot air outlet pipe 103, and a drying chamber 104 is fixedly installed inside the protective shell 101, and an air passage 105 is reserved between the outer wall of the drying chamber 104 and the protective shell 101, and the hot air inlet pipe 102 and the hot air outlet pipe 103 are both connected to the air passage 105, and two groups of air passages 106 are fixedly installed on the inner wall of the drying chamber 104, and both ends of the air passages 106 are connected to the air passages 105, and a driving motor 107 is fixedly installed on the top of the inner cavity of the drying chamber 104 through a mounting bracket, and the driving motor 1 07 is fixedly mounted with a stirring frame 108 at the output end, and a discharge pipe 109 is connected to the bottom of the protective shell 101. It is further explained that in order to realize the automatic input of the alternative fuel after drying into the alternative fuel delivery pipe 302, the feeding assembly 4 includes a screw feeder 401 and a first Roots blower 402. The screw feeder 401 is arranged below the drying bin 104, and the feed port of the screw feeder 401 is connected to the bottom end of the discharge pipe 109, the output end of the screw feeder 401 is connected to the discharge pipe 109, the output end of the first Roots blower 402 is connected to the first air duct 403, one end of the discharge pipe 109 is connected to the first air duct 403, and one end of the first air duct 403 is connected to one end of the alternative fuel delivery pipe 302.

[0021] As a preferred solution, in order to realize the automatic transportation of coal powder, the coal powder injection assembly 2 includes a second Roots blower 201 and a coal powder conveyor 202, the output end of the second Roots blower 201 is connected to the second air duct 203, the output end of the coal powder conveyor 202 is connected to the second air duct 203, and one end of the second air duct 203 is connected to one end of the coal powder injection pipe 303.

[0022] As a preferred solution, in order to ensure the full combustion of coal powder and alternative fuel, the blowing assembly 5 includes a single-end air sleeve 501 and a blower 502. The outer periphery of the single-end air sleeve 501 is fixedly connected to the inner wall of the main pipeline 301. A single-end swirl air sleeve 503 is also arranged inside the single-end air sleeve 501. One end of the single-end air sleeve 501 and the single-end swirl air sleeve 503 are provided with mounting holes 504. One end of the alternative fuel delivery pipe 302, the coal powder injection pipe 303 and the ignition pipe 304 are all arranged through the two mounting holes 504. The heat insulation material 305 is filled in Inside the single-end swirl air sleeve 503, a number of axial air holes 505 are evenly spaced apart at the other end of the single-end air sleeve 501, one end of the single-end air sleeve 501 is connected with an air inlet pipe 506, and the air inlet pipe 506 is connected with the output end of the blower 502 through a pipeline, and a number of swirl air holes 507 are evenly spaced apart at the other end of the single-end swirl air sleeve 503, one end of the single-end swirl air sleeve 503 is connected with an air passage 508, one end of the air passage 106 is welded and fixed to the inside of the single-end air sleeve 501, and is connected to the single-end air sleeve 501.

[0023] Further explanation, in order to increase the diffusion area of ​​pulverized coal, the bottom of the pulverized coal injection pipe 303 is connected to a bypass pipe 3031, and an annular pulverized coal channel 3032 used in conjunction with the bypass pipe 3031 is separated between the inner wall of the single-head air sleeve 501 and the outer wall of the single-head swirl air sleeve 503.

[0024] The steps for using the above system include: After the external hot air passes through the hot air inlet pipe 102 and enters the air channel 105 and the air pipe 106, it is discharged from the hot air outlet pipe 103. During the process, the hot air heats the drying chamber 104 to dry the alternative fuel inside the drying chamber 104. During the process, the driving motor 107 is started, and the driving motor 107 drives the stirring frame 108 to rotate, stirring the alternative fuel, and accelerating the drying of the alternative fuel; When delivering alternative fuel, the screw feeder 401 is started, and the alternative fuel dried in the drying bin 104 enters the screw feeder 401 through the discharge pipe 109 and is delivered to the first air duct 403 by the screw feeder 401, and the first Roots blower 402 is started to accelerate the flow of air in the first air duct 403, and the alternative fuel is blown to the alternative fuel delivery pipe 302; When conveying pulverized coal, the pulverized coal conveyor 202 is started to convey the pulverized coal to the second air guide pipe 203, and the second Roots blower 201 is started to blow the pulverized coal into the pulverized coal injection pipe 303, and part of the pulverized coal enters the annular pulverized coal channel 3032 through the diversion pipe 3031; The blower 502 is started to accelerate the air to pass through the air inlet pipe 506 and then blow it out from the axial air hole 505. At the same time, part of the air passes through the air pipe 508 and blows out from the swirl air hole 507, so that the coal powder is mixed with the alternative fuel; During the process, the ignitable gas is ignited by the igniter, and the generated flame passes through the ignition tube 304 to ignite the coal powder and the alternative fuel.

[0025] As an extended explanation, in order to realize automatic control and regulation of the device, a first sensor group is installed at the hot gas inlet pipe 102, a second sensor group is installed at the hot gas outlet pipe 103, a third sensor group is installed at the injection end side of the coal powder injection pipe 303, and a fourth sensor group is installed at the input end side of the alternative fuel delivery pipe 302, wherein the first sensor group, the second sensor group, the third sensor group and the fourth sensor group are all assembled from temperature, pressure and flow sensors, and a kiln head industrial fire-watching TV is installed on the outside of the other end of the main pipeline 301. The first sensor group, the second sensor group, the third sensor group and the fourth sensor group collect data into an integrated box, and the integrated box transmits the collected real-time data of temperature, pressure and flow to the DCS control system. The DCS control system transmits these data to the PID controller. The PID controller compares and calculates the received real-time data with the preset target value, and obtains the adjustment value of the control amount. The PID controller then feeds back the adjustment value to the DCS control system, and then the DCS control system sends a control instruction to adjust the supply of alternative fuel and coal powder, and adjust the hot air volume of the hot gas inlet pipe 102 and the hot gas outlet pipe 103.

Claims

1. An integrated combustion system of alternative fuels and fossil fuels for cement kilns, characterized in that: The invention comprises an alternative fuel drying component (1), a coal powder injection component (2) and a combustion component (3), wherein the output end of the alternative fuel drying component (1) is provided with a feeding component (4), and the output ends of the feeding component (4) and the coal powder injection component (2) are both connected to the input end of the combustion component (3): The combustion assembly (3) comprises a main pipeline (301), one end of the interior of the main pipeline (301) penetrates and is fixedly mounted with a blowing assembly (5), one end of the interior of the blowing assembly (5) penetrates an alternative fuel delivery pipe (302), a coal powder injection pipe (303) and an ignition pipe (304), and the interior of the blowing assembly (5) and the periphery of the alternative fuel delivery pipe (302), the coal powder injection pipe (303) and the ignition pipe (304) are filled with a heat insulating material (305).

2. The alternative fuel and fossil fuel integrated combustion system for cement kiln according to claim 1, characterized in that: The alternative fuel drying assembly (1) comprises a protective shell (101), the tops of both sides of the protective shell (101) are respectively connected with a hot air inlet pipe (102) and a hot air outlet pipe (103), a drying chamber (104) is fixedly installed inside the protective shell (101), an air passage (105) is reserved between the outer wall of the drying chamber (104) and the protective shell (101), the hot air inlet pipe (102) and the hot air outlet pipe (103) are both connected with the air passage (105), and two groups of air passage pipes (106) are fixedly installed on the inner wall of the drying chamber (104), and both ends of the air passage pipes (106) are connected with the air passage (105); A driving motor (107) is fixedly mounted on the top of the inner cavity of the drying bin (104) via a mounting bracket, a stirring frame (108) is fixedly mounted on the output end of the driving motor (107), and a discharge pipe (109) is connected to the bottom of the protective housing (101).

3. The alternative fuel and fossil fuel integrated combustion system for cement kiln according to claim 2, characterized in that: The feeding assembly (4) comprises a screw feeder (401) and a first Roots blower (402); the screw feeder (401) is arranged below the drying bin (104); a feed port of the screw feeder (401) is connected to a bottom end of a discharge pipe (109); an output end of the screw feeder (401) is connected to the discharge pipe (109); an output end of the first Roots blower (402) is connected to a first air guide pipe (403); and one end of the discharge pipe (109) is connected to the first air guide pipe (403); One end of the first air guide pipe (403) is in communication with one end of the alternative fuel delivery pipe (302).

4. The alternative fuel and fossil fuel integrated combustion system for cement kiln according to claim 1, characterized in that: The pulverized coal injection assembly (2) comprises a second Roots blower (201) and a pulverized coal conveyor (202); the output end of the second Roots blower (201) is connected to a second air duct (203); and the output end of the pulverized coal conveyor (202) is connected to the second air duct (203); One end of the second air guide pipe (203) is in communication with one end of the pulverized coal injection pipe (303).

5. The alternative fuel and fossil fuel integrated combustion system for cement kiln according to claim 1, characterized in that: The blowing assembly (5) comprises a single-end air sleeve (501) and a blower (502); a single-end swirl air sleeve (503) is further arranged inside the single-end air sleeve (501); one end of each of the single-end air sleeve (501) and the single-end swirl air sleeve (503) is provided with a mounting hole (504); the other end of the single-end air sleeve (501) is provided with a plurality of axial air holes (505) at even intervals; one end of the single-end air sleeve (501) is connected to an air inlet pipe (506); the other end of the single-end swirl air sleeve (503) is provided with a plurality of swirl air holes (507) at even intervals; one end of the single-end swirl air sleeve (503) is connected to an air passage pipe (508); one end of the air passage pipe (106) is welded and fixed inside the single-end air sleeve (501) and is arranged in communication with the single-end air sleeve (501); The air inlet pipe (506) is connected to the output end of the blower (502) through a pipeline.

6. The alternative fuel and fossil fuel integrated combustion system for cement kiln according to claim 5, characterized in that: The outer periphery of the single-end air sleeve (501) is fixedly connected to the inner wall of the main pipeline (301).

7. The alternative fuel and fossil fuel integrated combustion system for cement kiln according to claim 5, characterized in that: The bottom of the pulverized coal injection pipe (303) is connected to a diverter pipe (3031), and an annular pulverized coal channel (3032) used in conjunction with the diverter pipe (3031) is provided between the inner wall of the single-end air jacket (501) and the outer wall of the single-end swirl air jacket (503).

8. The alternative fuel and fossil fuel integrated combustion system for cement kiln according to claim 5, characterized in that: One end of the alternative fuel delivery pipe (302), the coal powder injection pipe (303) and the ignition pipe (304) are all arranged to pass through the two mounting holes (504); The heat insulating material (305) is filled inside the single-end swirl air sleeve (503), and the heat insulating material (305) is composed of one or more of rock wool, glass fiber, and aerogel felt.

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