Cement kiln with waste heat recovery function and waste heat recovery method thereof

Abstract

The invention relates to the technical field of energy-saving kilns, and discloses a cement kiln with a waste heat recovery function and a waste heat recovery method thereof.The cement kiln comprises a cyclone dust collector and a waste heat boiler, the air outlet end of the cyclone dust collector is connected with the air inlet end of the waste heat boiler through an air pipe, and a heat insulation pipe is fixed to a discharging opening in the bottom end of the cyclone dust collector; the heat insulation pipe is used for storing dust, a discharger is installed at the bottom end of the heat insulation pipe, and a water inlet pipe is installed at the waste heat boiler water inlet end. The heat insulation pipe is arranged at the bottom end of the cyclone dust collector, and the water inlet pipe of the waste heat boiler penetrates through the heat insulation pipe, so that heat in coarse-grain dust can be absorbed, inlet water is preheated, the subsequent evaporation efficiency of water flow is improved, the energy utilization rate is increased, and a higher energy-saving effect is achieved; and the dust removal assembly is arranged in the waste heat boiler, accumulated dust can be automatically removed on line by controlling movement of the hollow rod, the heat conduction efficiency of the heat collection pipe is improved, the water flow heating efficiency is higher, and the energy-saving effect is further improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of energy-saving kiln, in particular to a cement kiln with waste heat recovery function and a waste heat recovery method thereof. BACKGROUND

[0002] The cement kiln is the core equipment in the cement production process, which is used to calcine raw materials such as limestone, clay and iron ore at high temperature to generate cement clinker, and then grind the cement clinker to produce cement. It is the link with the highest energy consumption and the largest carbon emission in the cement industry, accounting for more than 70% of the total plant energy consumption. During the production process, the cement kiln will produce a large amount of high-temperature waste gas (200-400 degrees Celsius) and clinker cooling waste heat (about 1000 degrees Celsius). These waste heat can be efficiently recovered and utilized through various ways, which can not only reduce energy consumption, but also reduce carbon emissions. The waste heat recovery of the cement kiln is mainly through the kiln head waste heat recovery equipment (AQC boiler) and the kiln tail waste heat recovery equipment (SP boiler), which produce medium and low pressure steam and superheated steam to drive the steam turbine to generate electricity.

[0003] The existing kiln tail waste heat boiler has certain problems in use: because the exhaust gas discharged from the kiln tail contains a large amount of dust, in order to reduce the wear of the kiln tail boiler caused by dust, a cyclone dust collector is needed to remove large-size dust, but there is still heat in the removed dust, and this part of heat cannot be recovered. In addition, dust is easy to adhere to the heat collecting pipe inside the waste heat boiler, and there is a lack of online automatic cleaning measures, which can easily lead to a decrease in the heat conduction performance of the heat collecting pipe, and further affect the heat recovery efficiency. SUMMARY

[0004] In view of the deficiencies of the prior art, the present application provides a cement kiln with waste heat recovery function and a waste heat recovery method thereof, which has the advantage of improving the waste heat recovery efficiency, and solves the problems of the current kiln tail waste heat boiler lacking measures for recovering heat from dust and lacking online automatic cleaning measures for the heat collecting pipe.

[0005] To solve the above technical problems, the present application provides the following technical scheme: a cement kiln with waste heat recovery function, comprising a cyclone dust collector and a waste heat boiler, the gas outlet end of the cyclone dust collector is connected to the gas inlet end of the waste heat boiler through a gas pipe, a heat insulation pipe is fixed to the bottom end of the cyclone dust collector, the heat insulation pipe is used to store dust, a dust discharger is installed at the bottom end of the heat insulation pipe, a water inlet pipe is installed on the water inlet end of the waste heat boiler, the water inlet pipe penetrates the heat insulation pipe, a heat collecting pipe and a dust removal assembly are installed inside the waste heat boiler, the dust removal assembly comprises a hollow rod which is sleeved on the heat collecting pipe and can vertically move, and the dust removal assembly is used to remove dust accumulated on the heat collecting pipe.

[0006] When the cyclone dust collector is running, coarse dust in the exhaust gas is collected and collected in the heat insulation pipe, and when the waste heat boiler is running, water is continuously supplied to the waste heat filter inside through the water inlet pipe, when the water inlet pipe passes through the heat insulation pipe, the heat of the coarse dust preheats the water, and the dust removal assembly is intermittently operated, forcing the hollow rod to move vertically along the heat collection pipe, thereby scraping off the accumulated dust attached to the outer wall of the heat collection pipe.

[0007] Preferably, the water inlet end of the water inlet pipe is connected with a water pump, the water inlet end of the water pump is connected with a water source, and the water inlet pipe is provided with a hollow box inside the heat insulation pipe for improving heat collection efficiency.

[0008] Preferably, the hollow box is provided as a flat aluminum box, a plurality of groups of staggered strip-shaped blocks are arranged inside the hollow box, the plurality of groups of strip-shaped blocks separate the inner cavity of the hollow box to form a zigzag-shaped water channel, and the two ends of the water channel are communicated with the water inlet pipe.

[0009] Preferably, the heat insulation pipe is provided as a vertical square tube, the heat insulation pipe is connected with the discharge port at the bottom end of the cyclone dust collector through a flange, the inner wall of the square tube is provided with two groups of vertically arranged sliding grooves symmetrically distributed, the two groups of sliding grooves are respectively located on both sides of the hollow box, ash removal assemblies are arranged on both sides of the hollow box, and the ash removal assemblies comprise a scraper capable of rotating and vertically moving.

[0010] Preferably, the ash removal assembly comprises a vertical cylinder fixed above the flange, the output end of the vertical cylinder extends into the vertical sliding groove and is fixed with a sliding block, the sliding block is in sliding connection with the vertical sliding groove, one end of the sliding block extends to the outside of the vertical sliding groove and is provided with a notch, one end of the scraper is fixed with a base shaft, the base shaft is in rotary connection with the inner wall of the notch, a torsional spring is connected between the base shaft and the sliding block, the length of the scraper is greater than the distance between the hollow box and the sliding block, the scraper comprises a handle and a tool bit fixed at the bottom end of the handle, and the base shaft is fixed at the top end of the handle.

[0011] Preferably, the top end of the handle is further fixed with a support rod, and a horizontal electromagnetic push rod is embedded and fixed on the sliding block, and the output end of the electromagnetic push rod faces the support rod.

[0012] Preferably, the dust removal assembly further comprises an upper rotating shaft and a lower rotating shaft, the upper rotating shaft is connected with the inner top wall of the waste heat boiler through an upper bearing seat, the lower rotating shaft is connected with the inner bottom wall of the waste heat boiler through a lower bearing seat, an upper sprocket is fixed on the upper rotating shaft, a lower sprocket is fixed on the lower rotating shaft, a chain is connected between the upper sprocket and the lower sprocket, the chain is fixedly connected with the hollow rod, and a motor is further fixed in the waste heat boiler, and the output end of the motor is fixedly connected with the end of the lower rotating shaft.

[0013] Preferably, a plurality of spade rings are fixed at the bottom of the hollow rod, and the spade rings are sleeved on the heat collection pipe.

[0014] Preferably, a main branch pipe is fixed on the water inlet pipe, a secondary branch pipe is fixed on the main branch pipe, one end of the secondary branch pipe extends into the waste heat boiler and is fixedly connected with a hollow rod, a plurality of nozzles are fixed on the hollow rod, the nozzles are directed towards the heat collecting pipe at the bottom of the hollow rod, and a reagent barrel is further fixed on the outer wall of the waste heat boiler, the reagent barrel is provided with a discharging pipe at the bottom end and is connected with the main branch pipe.

[0015] The application further discloses a waste heat recovery method.

[0016] Compared with the prior art, the application provides a cement kiln with a waste heat recovery function and a waste heat recovery method thereof, and has the following beneficial effects:

[0017] 1. The cement kiln with a waste heat recovery function and the waste heat recovery method thereof can absorb heat from coarse dust, preheat the water inlet, improve the subsequent evaporation efficiency of the water flow, improve the energy utilization rate, have higher energy-saving effect, and automatically remove accumulated dust in the waste heat boiler through the dust removal assembly and the movement of the hollow rod, improve the heat conduction efficiency of the heat collecting pipe, make the water flow heating efficiency higher, and further improve the energy-saving effect.

[0018] 2. The cement kiln with a waste heat recovery function and the waste heat recovery method thereof can improve the residence time of the water flow in the heat preservation box, improve the water flow heat absorption efficiency, save more energy, and facilitate the movement of the scraper after being attached to the outer wall of the heat preservation box, thereby removing the accumulated dust on the outer wall of the heat preservation box, improving the heat conduction efficiency of the heat preservation box, and improving the heat utilization rate.

[0019] 3. The cement kiln with a waste heat recovery function and the waste heat recovery method thereof can use the water flow mixed with the chemical cleaning agent to enter the secondary branch pipe, the hollow rod, and the nozzle to spray the stubborn skin on the heat collecting pipe when the dust removal assembly cannot clean the stubborn skin, soften and corrode the skin, and then start the dust removal assembly again to control the movement of the hollow rod to scrape off the skin, thereby significantly improving the cleaning effect of the skin. DETAILED DESCRIPTION

[0020] Figure 1 is a three-dimensional structure diagram of the cement kiln with a waste heat recovery function Figure 1 ;

[0021] Figure 2 is a three-dimensional structure diagram of the cement kiln with a waste heat recovery function Figure 2 ;

[0022] Figure 3 is a sectional view of the waste heat boiler of the present application;

[0023] Figure 4 is a schematic view of the internal structure of the heat insulation pipe of the present application;

[0024] Figure 5 is an exploded view of the structure of the hollow box of the present application;

[0025] Figure 6 is a partial sectional view of the working state of the scraper of the present application;

[0026] Figure 7 is an enlarged view of A of the present application; Figure 6

[0027] Figure 8 is a schematic view of the dust removal assembly of the present application;

[0028] Figure 9 is a schematic view of the mounting structure of the sub-branch pipe of the present application;

[0029] Figure 10 is an enlarged view of B of the present application; Figure 9

[0030] In the figure: 1, cyclone dust collector; 2, waste heat boiler; 3, air pipe; 4, heat insulation pipe; 5, discharger; 6, water inlet pipe; 7, heat collecting pipe; 8, dust removal assembly; 81, hollow rod; 82, upper rotating shaft; 83, lower rotating shaft; 84, upper bearing seat; 85, lower bearing seat; 86, upper sprocket; 87, lower sprocket; 88, chain; 89, motor; 810, scraper ring; 9, water pump; 10, hollow box; 11, strip-shaped stop block; 12, water channel; 13, flange; 14, vertical sliding groove; 15, ash removal assembly; 151, scraper; 152, vertical air cylinder; 153, sliding block; 154, torsional spring; 155, supporting rod; 156, electromagnetic push rod; 157, base shaft; 16, main branch pipe; 17, sub-branch pipe; 18, nozzle; 19, reagent barrel; 20, discharging pipe. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0032] ​​As introduced in the background, in order to solve the above technical problems, the present application provides a cement kiln with waste heat recovery function and a waste heat recovery method thereof.

[0033] Embodiment one: please refer to Figures 1-4 A cement kiln with waste heat recovery function, comprising a cyclone dust collector 1 and a waste heat boiler 2, the gas outlet end of the cyclone dust collector 1 is connected with the gas inlet end of the waste heat boiler 2 through a gas pipe 3, characterized in that: a heat insulation pipe 4 is fixed at the bottom end of the cyclone dust collector 1, the heat insulation pipe 4 is used for storing dust, a discharger 5 is installed at the bottom end of the heat insulation pipe 4, a water inlet pipe 6 is installed at the water inlet end of the waste heat boiler 2, the water inlet pipe 6 penetrates the heat insulation pipe 4, a heat collecting pipe 7 and a dust removal assembly 8 are installed inside the waste heat boiler 2, the dust removal assembly 8 comprises a hollow rod 81 which is sleeved on the heat collecting pipe 7 and can move vertically, and the dust removal assembly 8 is used for removing dust accumulated on the heat collecting pipe 7.

[0034] When the cyclone dust collector 1 is running, coarse dust in the exhaust gas is collected and stored in the heat insulation pipe 4, and when the waste heat boiler 2 is running, water is continuously supplied to the inside of the waste heat filter through the water inlet pipe 6, when the water inlet pipe 6 penetrates the heat insulation pipe 4, the heat of the coarse dust preheats the water, and the dust removal assembly 8 is intermittently operated, forcing the hollow rod 81 to move vertically along the heat collecting pipe 7, thereby scraping off the dust accumulated on the outer wall of the heat collecting pipe 7.

[0035] Wherein, the heat insulation pipe 4 is insulated by externally coating heat insulation material, the hollow rod 81 is hollow inside, and in the initial state, the hollow rod 81 is arranged at the top end of the heat collecting pipe 7, and in actual application, multiple groups of heat collecting pipes 7 are arranged inside the waste heat boiler 2, and the number of hollow rods 81 matches the number of groups of heat collecting pipes 7;

[0036] In use, the cyclone dust collector 1 and the waste heat boiler 2 are started, the cyclone dust collector 1 removes coarse dust in the exhaust gas, and then the exhaust gas is transported to the waste heat boiler 2 through the gas pipe 3, water is continuously supplied to the waste heat boiler 2 through the water inlet pipe 6, heat recovery is realized when the exhaust gas passes through the heat collecting pipe 7 inside the waste heat boiler 2, and the water inside the heat collecting pipe 7 is heated, and finally steam is discharged, while the coarse dust collected by the cyclone dust collector 1 falls into the heat insulation pipe 4 through the bottom discharge port, the heat of the coarse dust is conducted to the water in the water inlet pipe 6 to preheat the water, realizing the utilization of the heat in the dust, and when the preheating boiler is running, the dust removal assembly 8 is intermittently operated, forcing the hollow rod 81 to move along the heat collecting pipe 7, and when the hollow rod 81 moves, the dust accumulated on the outer wall of the heat collecting pipe 7 is scraped off, so that the dust falls down, avoiding the influence of the dust on the heat conduction performance;

[0037] By setting the heat insulation pipe 4 at the bottom end of the cyclone dust collector 1 and passing the water inlet pipe 6 of the waste heat boiler 2 through the heat insulation pipe 4, the heat in the coarse dust can be absorbed, the preheating of the water inlet is realized, and the subsequent evaporation efficiency of the water flow is improved, the energy utilization rate is improved, and the energy saving effect is higher. And by setting the dust removal assembly 8 inside the waste heat boiler 2, the accumulated dust can be automatically removed online by controlling the movement of the hollow rod 81, the heat conduction efficiency of the heat collecting pipe 7 is improved, the water flow heating efficiency is higher, and the energy saving effect is further improved.

[0038] Example two: refer to Figures 2-6 Unlike the above-mentioned embodiment, the water inlet pipe 6 is connected with a water pump 9 at the water inlet end, the water inlet end of the water pump 9 is connected with a water source, and the water inlet pipe 6 is located inside the heat insulation pipe 4 and is provided with a hollow box 10 for improving the heat collecting efficiency. The hollow box 10 is an aluminum box in a flat shape, a plurality of groups of staggered strip-shaped blocking pieces 11 are arranged inside the hollow box 10, the plurality of groups of strip-shaped blocking pieces 11 divide the inner cavity of the hollow box 10 to form a zigzag-shaped water channel 12, and both ends of the water channel 12 are communicated with the water inlet pipe 6.

[0039] When the waste heat boiler 2 is running, the water pump 9 is running synchronously, and then the water source is pumped into the water inlet pipe 6. In use, the water flow enters the hollow box 10 from the water inlet pipe 6, flows along the water channel 12 inside the hollow box 10, and then flows out to the water inlet pipe 6 again. Since the hollow box 10 has high heat conductivity, it can absorb the heat in the coarse dust. When the water flow passes through the inside of the hollow box 10, it is also heated, thereby realizing heat recovery. When the unloader 5 is started, the low-temperature coarse dust in the heat insulation pipe 4 can be controlled to fall downward, and at the same time, the high-temperature coarse dust in the cyclone dust collector 1 falls into the heat insulation pipe 4, so that the heat insulation pipe 4 can maintain a high temperature;

[0040] By setting the hollow box 10, the residence time of the water flow in the heat preservation box can be improved, the water flow heat absorption efficiency is improved, and the energy saving effect is better.

[0041] Example three, refer to Figures 5-10The heat insulation pipe 4 is arranged as a vertical square pipe, and is connected with the discharge port at the bottom end of the cyclone dust collector 1 through a flange 13. Two groups of vertical sliding grooves 14 are arranged on the inner wall of the square pipe and are symmetrically distributed. The two groups of sliding grooves are respectively located on the two sides of the hollow box 10. Ash removal assemblies 15 are arranged on the two sides of the hollow box 10. The ash removal assembly 15 comprises a scraper 151 capable of rotating and vertically moving. The ash removal assembly 15 comprises a vertical air cylinder 152 fixed above the flange 13. The output end of the vertical air cylinder 152 extends into the vertical sliding groove 14 and is fixed with a sliding block 153. The sliding block 153 is in sliding connection with the vertical sliding groove 14. One end of the sliding block 153 extends to the outside of the vertical sliding groove 14 and is provided with a notch. One end of the scraper 151 is fixed with a base shaft 157. The base shaft 157 is in rotating connection with the inner wall of the notch. A torsional spring 154 is connected between the base shaft 157 and the sliding block 153. The length of the scraper 151 is greater than the distance between the hollow box 10 and the sliding block 153. The scraper 151 comprises a handle and a tool bit fixed at the bottom end of the handle. The base shaft 157 is fixed at the top end of the handle. A supporting rod 155 is further fixed at the top end of the handle. A horizontal electromagnetic push rod 156 is embedded on the sliding block 153. The output end of the electromagnetic push rod 156 faces the supporting rod 155.

[0042] The bottom end of the vertical sliding groove 14 is arranged as an inclined surface. When the sliding block 153 moves downward along the vertical sliding groove 14, the accumulated ash in the vertical sliding groove 14 is pushed out, which facilitates the discharge of the accumulated ash along the inclined surface. The hollow box 10 is arranged at the center of the square pipe. In the initial state, the electromagnetic push rod 156 is elongated and abuts against the supporting rod 155. The torsional spring 154 is in a deformed state, and the sliding block 153 is located at the highest point of the vertical sliding groove 14. In actual application, calcium-silicon-aluminum oxides exist in coarse dust, which easily adhere to the outer side of the hollow box 10 in the heat insulation pipe 4, thereby affecting the heat conduction efficiency. Therefore, after each use, the accumulated ash on the two sides of the hollow box 10 is cleaned by starting the ash removal assembly 15. In use, the electromagnetic push rod 156 is started first. After the electromagnetic push rod 156 is retracted, the base shaft 157 is forced to rotate under the elastic force of the torsional spring 154, thereby driving the scraper 151 to swing. After the scraper 151 swings, the tool bit contacts the outer wall of the hollow box 10. Then, the vertical air cylinder 152 is started. The vertical air cylinder 152 is elongated to push the sliding block 153 to move downward. When the sliding block 153 moves, the scraper 151 moves downward. When the scraper 151 moves downward, the accumulated ash on the outer wall of the hollow box 10 is cleaned. Then, the vertical air cylinder 152 and the electromagnetic push rod 156 are controlled to reset in sequence, and the scraper 151 is controlled to re-adhere to the inner wall of the heat insulation pipe 4.

[0043] The arrangement of the ash removal assembly 15 facilitates the movement of the scraper 151 after adhering to the outer wall of the hollow box 10, thereby removing the accumulated ash on the outer wall of the hollow box 10, improving the heat conduction efficiency of the hollow box 10, improving the heat utilization rate, and saving energy.

[0044] Embodiment four, refer to Figures 5-10 Unlike the above embodiment, the dust removal assembly 8 further comprises an upper rotating shaft 82 and a lower rotating shaft 83, the upper rotating shaft 82 is connected with the inner top wall of the waste heat boiler 2 through an upper bearing seat 84, the lower rotating shaft 83 is connected with the inner bottom wall of the waste heat boiler 2 through a lower bearing seat 85, an upper chain wheel 86 is fixed on the upper rotating shaft 82, a lower chain wheel 87 is fixed on the lower rotating shaft 83, a chain 88 is connected between the upper chain wheel 86 and the lower chain wheel 87, the chain 88 is fixedly connected with the hollow rod 81, a motor 89 is further fixed in the waste heat boiler 2, the output end of the motor 89 is fixedly connected with the end of the lower rotating shaft 83, a plurality of scraper rings 810 are fixed on the bottom of the hollow rod 81, and the scraper rings 810 are sleeved on the heat collecting pipe 7.

[0045] Among them, the upper chain wheel 86, the lower chain wheel 87 and the chain 88 are arranged as multiple groups and matched with multiple groups of hollow rods 81 respectively, the scraper rings 810 are made of wear-resistant steel material, in use, the motor 89 operates to drive the lower rotating shaft 83 to rotate, the lower rotating shaft 83 drives the lower chain wheel 87 to rotate when rotating, the lower chain wheel 87 drives the chain 88 to move when rotating, and in turn drives the upper chain wheel 86 to rotate, the chain 88 pulls the hollow rod 81 to move downward when moving, and the scraper rings 810 move downward with the hollow rod 81 when the hollow rod 81 moves downward, thereby scraping off the dust on the heat collecting pipe 7;

[0046] By arranging the dust removal assembly 8, the motor 89 can drive multiple hollow rods 81 to move downward, thereby scraping off the dust on the surface of the heat collecting pipe 7, improving the heat conduction efficiency of the heat collecting pipe 7, and in turn improving the waste heat recovery efficiency.

[0047] Embodiment five, refer to Figures 5-10 Unlike the above embodiment, the water inlet pipe 6 is fixed with a main branch pipe 16, the main branch pipe 16 is fixed with a secondary branch pipe 17, one end of the secondary branch pipe 17 extends into the waste heat boiler 2 and is fixedly connected with the hollow rod 81, a plurality of nozzles 18 are fixed on the hollow rod 81, the nozzles 18 are directed to the heat collecting pipe 7 at the bottom of the hollow rod 81, a reagent barrel 19 is further fixed on the outer wall of the waste heat boiler 2, a discharge pipe 20 is arranged at the bottom end of the reagent barrel 19 and connected with the main branch pipe 16.

[0048] The water inlet pipe 6, the main branch pipe 16 and the blanking pipe 20 are all provided with valves, and the reagent barrel 19 is filled with chemical cleaning agent. In actual application, when there is stubborn scale on the heat collecting pipe 7 and the scale cannot be removed by the hollow rod 81, the opening and closing of the valve is controlled, so that the water flow in the water inlet pipe 6 flows into the branch pipe, and the chemical cleaning agent in the reagent barrel 19 flows into the branch pipe. After the water flow and the chemical cleaning agent are mixed, they enter the auxiliary branch pipe 17, the hollow rod 81, and are sprayed to the stubborn scale position on the heat collecting pipe 7 through the nozzle 18, so as to soften and corrode the scale. Then the dust removal assembly 8 is started again, and the hollow rod 81 is controlled to move to scrape off the scale position, thereby significantly improving the cleaning effect on the scale.

[0049] Embodiment six is a waste heat recovery method, which uses the cement kiln with the waste heat recovery function in the above embodiments.

[0050] Although the embodiments of the present application have been shown and described, it is to be understood that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A cement kiln with waste heat recovery function, comprising a cyclone dust collector (1) and a waste heat boiler (2), wherein the outlet end of the cyclone dust collector (1) and the inlet end of the waste heat boiler (2) are connected by an air pipe (3), characterized in that: The discharge port at the bottom of the cyclone dust collector (1) is fixed with a heat insulation pipe (4), which is used to store dust. A discharger (5) is installed at the bottom of the heat insulation pipe (4). A water inlet pipe (6) is installed on the water inlet end of the waste heat boiler (2). The water inlet pipe (6) passes through the heat insulation pipe (4). A heat collection pipe (7) and a dust removal assembly (8) are installed inside the waste heat boiler (2). The dust removal assembly (8) includes a hollow rod (81) sleeved on the heat collection pipe (7) and capable of vertical movement. The dust removal assembly (8) is used to remove the accumulated dust on the heat collection pipe (7). When the cyclone dust collector (1) is running, it collects coarse dust particles in the exhaust gas and collects them in the heat insulation tube (4). When the waste heat boiler (2) is running, it continuously supplies water to the inside of the waste heat filter through the water inlet pipe (6). When the water inlet pipe (6) passes through the heat insulation tube (4), the heat of the coarse dust particles preheats the water. The dust removal component (8) operates intermittently, forcing the hollow rod (81) to move vertically along the heat collection tube (7), thereby scraping off the accumulated dust attached to the outer wall of the heat collection tube (7).

2. A cement kiln with waste heat recovery function according to claim 1, characterized in that: The water inlet pipe (6) is connected to a water pump (9) at its inlet end. The water pump (9) is connected to an external water source at its inlet end. A hollow box (10) for improving heat collection efficiency is installed in a section of the water inlet pipe (6) inside the heat insulation pipe (4).

3. A cement kiln with waste heat recovery function according to claim 2, characterized in that: The hollow box (10) is a flat aluminum box. The hollow box (10) has multiple sets of staggered strip blocks (11) inside. The multiple sets of strip blocks (11) divide the inner cavity of the hollow box (10) into a tortuous water channel (12). Both ends of the water channel (12) are connected to the water inlet pipe (6).

4. A cement kiln with waste heat recovery function according to claim 1, characterized in that: The heat insulation pipe (4) is a vertically arranged square pipe. The heat insulation pipe (4) is connected to the discharge port at the bottom of the cyclone dust collector (1) through a flange (13). The inner wall of the square pipe is provided with two sets of symmetrically distributed vertical sliding grooves (14). The two sets of sliding grooves are located on both sides of the hollow box (10). The hollow box (10) is provided with dust removal components (15) on both sides. The dust removal components (15) include a scraper (151) that can rotate and move vertically.

5. A cement kiln with waste heat recovery function according to claim 4, characterized in that: The dust removal assembly (15) includes a vertical cylinder (152) fixed above the flange (13). The output end of the vertical cylinder (152) extends into the interior of the vertical slide groove (14) and is fixed with a slider (153). The slider (153) is slidably connected to the vertical slide groove (14). One end of the slider (153) extends to the outside of the vertical slide groove (14) and is provided with a notch. One end of the scraper (151) is fixed with a base shaft (157). The base shaft (157) is rotatably connected to the inner wall of the notch. A torsion spring (154) is connected between the end of the base shaft (157) and the slider (153). The length of the scraper (151) is greater than the distance between the hollow box (10) and the slider (153). The scraper (151) includes a handle and a blade head fixed at the bottom of the handle. The base shaft (157) is fixed at the top of the handle.

6. A cement kiln with waste heat recovery function according to claim 5, characterized in that: The top of the handle is also fixed with a support rod (155), and a horizontal electromagnetic push rod (156) is fixedly embedded on the slider (153), with the output end of the electromagnetic push rod (156) facing the support rod (155).

7. A cement kiln with waste heat recovery function according to claim 1, characterized in that: The dust removal assembly (8) also includes an upper rotating shaft (82) and a lower rotating shaft (83). The upper rotating shaft (82) is connected to the inner top wall of the waste heat boiler (2) through an upper bearing seat (84), and the lower rotating shaft (83) is connected to the inner bottom wall of the waste heat boiler (2) through a lower bearing seat (85). An upper sprocket (86) is fixed on the upper rotating shaft (82), and a lower sprocket (87) is fixed on the lower rotating shaft (83). A chain (88) is connected between the upper sprocket (86) and the lower sprocket (87). The chain (88) is fixedly connected to a hollow rod (81). A motor (89) is also fixed inside the waste heat boiler (2). The output end of the motor (89) is fixedly connected to the end of the lower rotating shaft (83).

8. A cement kiln with waste heat recovery function according to claim 7, characterized in that: The hollow rod (81) has multiple shovel rings (810) fixed at its bottom, and the shovel rings (810) are sleeved on the heat collection tube (7).

9. A cement kiln with waste heat recovery function according to claim 7, characterized in that: A main branch pipe (16) is fixed on the water inlet pipe (6), and a secondary branch pipe (17) is fixed on the main branch pipe (16). One end of the secondary branch pipe (17) extends into the waste heat boiler (2) and is fixedly connected to the hollow rod (81). Multiple nozzles (18) are fixed on the hollow rod (81). The nozzles (18) face the heat collection pipe (7) at the bottom of the hollow rod (81). A reagent barrel (19) is also fixed on the outer wall of the waste heat boiler (2). A discharge pipe (20) is provided at the bottom of the reagent barrel (19) and is connected to the main branch pipe (16).

10. A waste heat recovery method, characterized in that: This waste heat recovery method uses a cement kiln with waste heat recovery function as described in any one of claims 1-9.

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