Alternative fuel auxiliary incineration system for cement kiln

Abstract

The utility model relates to the technical field of rotary kilns, in particular to an alternative fuel auxiliary incineration system for a cement kiln. Comprising a rotary kiln, a decomposing furnace and an air pipe, the rotary kilns comprise the first rotary kiln and the second rotary kiln, the first rotary kiln has an inclination angle in the horizontal direction, a kiln head device and a kiln tail device are arranged at the two ends of the first rotary kiln respectively, the kiln head device is connected with the conveying device and the air pipe, the kiln tail device is connected with the decomposing furnace, the decomposing furnace is connected with the second rotary kiln, and the second rotary kiln is connected with the grate cooler. The first rotary kiln is composed of a barrel, a lifting plate and a blocking plate, the interior of the barrel is divided into two areas, the position close to a kiln head device is a drying pre-combustion area, and the position close to a kiln tail device is a main combustion area. The utility model has the advantages that materials are more uniformly distributed in the drying pre-combustion area and the main combustion area, the drying and the combustion of the materials are facilitated, and the application range of alternative fuels is widened.

Description

Technical field:

[0001] The utility model relates to the technical field of rotary kilns, in particular to an alternative fuel auxiliary incineration system for cement kilns. Background technology:

[0002] In the cement industry, more and more cement production enterprises have begun to use alternative fuels to replace part of the coal in production. There are many types of alternative fuels, including various domestic garbage, municipal sludge, hazardous waste, and various biomass and other materials. At present, most of the alternative fuels are delivered directly by direct delivery. The conveying equipment directly delivers them into the decomposition furnace of the preheater through the unloading chute. The alternative fuel is directly burned in the decomposition furnace, and the heat generated by the combustion can replace part or all of the tail coal input. This direct feeding method is more friendly to flammable waste textiles and waste plastic materials. The materials can burn quickly after entering the decomposition furnace, but the effect is not good for non-flammable materials such as high water content, dense materials, and large particles. After entering the decomposition furnace, these materials will not only not burn quickly, but may also cause the temperature in the decomposition furnace to drop, affecting the stability of the system; in addition, the airflow in the decomposition furnace may not be able to support large pieces of dense materials. Large pieces of materials directly enter the rotary kiln from the bottom of the decomposition furnace. Light materials that are not quickly burned in the decomposition furnace will enter the upper preheater with the airflow, resulting in "afterburning" phenomenon, affecting the stability of the entire kiln system.

[0003] In the prior art, patent application number: 202121904969.3 discloses a fan for a cement rotary kiln decomposition furnace, which specifically includes a rotary kiln body, the rotary kiln body is connected to a cooler, one end of the rotary kiln body is fixedly connected to a decomposition furnace, the cooler is fixedly connected to a third air duct, the third air duct is fixedly connected to a fourth air duct and connected to the fan body, the bottom of the fan body is abutted against a support platform, and the air outlet of the fan body is connected to the decomposition furnace through the fifth and sixth air ducts. The technical solution is to improve the pyrolysis efficiency by blowing air through the cooler.

[0004] At present, cement kilns continue to explore how to make materials of different sizes burn easily while achieving efficient pyrolysis based on the application of rotary kilns, so as to avoid problems in the cement kiln combustion system caused by the difficulty in burning large-particle materials and dense materials. Utility model content:

[0005] The purpose of the utility model is to provide a substitute fuel auxiliary incineration system for a cement kiln, which can effectively solve the technical problems in the background technology.

[0006] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0007] The utility model discloses an alternative fuel auxiliary incineration system for a cement kiln, comprising a rotary kiln, a decomposition furnace and an air duct; the rotary kiln comprises a No. 1 rotary kiln and a No. 2 rotary kiln respectively, the No. 1 rotary kiln has an inclination angle in the horizontal direction, the two ends of the No. 1 rotary kiln are respectively a kiln head device and a kiln tail device, the kiln head device is respectively connected to a conveying device and an air duct, the kiln tail device is connected to the decomposition furnace, the lower end of the decomposition furnace is connected to an inlet at one end of the No. 2 rotary kiln, the other end of the No. 2 rotary kiln is connected to a grate cooler, and the grate cooler is also connected to the air duct; the air duct comprises a bypass air duct and a tertiary air duct, one end of the bypass air duct is connected to the kiln head device, and the other end is connected to the tertiary air duct, one end of the tertiary air duct is connected to the grate cooler, and the other end is connected to the decomposition furnace;

[0008] The No. 1 rotary kiln consists of a cylinder, a lifting plate and a material blocking plate. A lifting plate is arranged on the inner wall of the cylinder near the kiln head device along the axial direction of the cylinder. Multiple lifting plates are evenly distributed in parallel along the circumference of the cylinder. The lifting plates all protrude inwardly. A material blocking plate is arranged between every two lifting plates, dividing the interior of the cylinder into two areas. The area near the kiln head device is a drying and pre-combustion area, and the area near the kiln tail device is a main combustion area.

[0009] Furthermore, each of the material blocking plates is connected to two adjacent parallel material lifting plates, and the multiple material blocking plates are located at different positions, thereby dividing the drying and pre-combustion area into multiple semi-enclosed areas of different sizes.

[0010] Furthermore, a material lifting plate is provided on the inner wall of the cylinder near the kiln tail device along the axial direction of the cylinder, and a plurality of material lifting plates are evenly distributed in parallel along the circumference of the cylinder, and all the material lifting plates protrude inwards.

[0011] Furthermore, a gate valve is provided on the bypass air duct, and another gate valve is provided on the tertiary air duct.

[0012] Furthermore, the kiln head device is connected to the conveying device through a first material discharge chute, and two gate valves are respectively provided on the first material discharge chute, and the two gate valves are arranged at a certain distance; the kiln tail device is connected to the decomposition furnace through a second material discharge chute, and a gate valve is also provided on the second material discharge chute.

[0013] Furthermore, a tugboat device is provided under the No. 1 rotary kiln, and the tugboat device lifts the No. 1 rotary kiln and forms an angle of 3° to 12° with the horizontal direction. The No. 1 rotary kiln performs a rotary motion on the tugboat device through a connected driving device.

[0014] The advantages of the utility model are as follows: the system is provided with a No. 1 rotary kiln and a No. 2 rotary kiln. When the alternative fuel is in the No. 1 rotary kiln, large particles or dense materials are intercepted by the lifting plate and the blocking plate. Through the rotary motion of the No. 1 rotary kiln, the materials are distributed more evenly in the drying and pre-combustion zone, which is more conducive to the drying and combustion of the materials, eliminates the influence of the direct combustion of the materials in the decomposition furnace on the system, and improves the application range of the alternative fuel.

[0015] Under the movement of the No. 1 rotary kiln, the materials in the drying and pre-combustion zone gradually move to the main combustion zone. The lifting plate in the main combustion zone can lift and disperse the burning materials more evenly, prevent the materials from accumulating in a local area, make the materials burn quickly and violently, and eliminate the problem that the materials directly fall into the No. 2 rotary kiln after entering the decomposition furnace. At the same time, the phenomenon of "afterburning" of materials is avoided to ensure the stability of the entire system. Description of the drawings:

[0016] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0017] Figure 2 This is a cross-sectional schematic diagram of the No. 1 rotary kiln of the utility model;

[0018] Figure 3 This is a top view of the main combustion area of ​​the No. 1 rotary kiln of the utility model;

[0019] Figure 4 This is a top view schematic diagram of the drying and pre-combustion zone of the No. 1 rotary kiln of the utility model;

[0020] In the figure:

[0021] 1. Decomposition furnace 2. No. 1 rotary kiln 3. Unloading chute 1

[0022] 4. Metering and conveying device 5. Gate valve 1 6. Gate valve 2

[0023] 7. Bypass air duct 8. Gate valve 3 9. Kiln head device

[0024] 10. Tugboat Group 1 11. Driving Device 12. Tugboat Group 2

[0025] 13. Kiln tail device 14. Gate valve 4 15. Unloading chute 2

[0026] 16. Tertiary air duct 16.1. Gate valve 5 17. No. 2 rotary kiln

[0027] 2-1, lifting plate 1 2-2, wheel belt 2 2-3, large gear

[0028] 2-4, wheel belt 1 2-5, lifting plate 2 2-6, blocking plate

[0029] 2-7, Cylinder A, Drying and Preheating Combustion Zone B, Main Combustion Zone

[0030] 18. Grate cooler Specific embodiment:

[0031] A cement kiln alternative fuel auxiliary incineration system comprises a No. 1 rotary kiln 2 and a No. 2 rotary kiln 17, a decomposition furnace 1 and an air duct; the No. 1 rotary kiln 2 has an angle of 10° with the horizontal direction, is supported by a tugboat group 10 and a tugboat group 2 12, and is driven by a driving device 11 to continuously rotate the No. 1 rotary kiln 2; the two ends of the No. 1 rotary kiln 2 are a kiln head device 9 and a kiln tail device 13 respectively; the kiln head device 9 is sealed with the outer circumference of the No. 1 rotary kiln 2 to prevent leakage and cold air from entering, the upper part of the kiln head device 9 is connected to the lower part of a material discharge chute 1 3, and the right side of the kiln head device 9 is connected to a bypass air duct 7; the kiln tail device 13 is located on the left side of the No. 1 rotary kiln 2, and is sealed with the outer circumference of the No. 1 rotary kiln 2 to prevent leakage and cold air from entering, and the lower part of the kiln tail device 13 is connected to the upper end of the material discharge chute 2 15; the material discharge chute 1 3 is equipped with a gate valve 1 5 and a gate valve 2 6, The upper end of the unloading chute 1 3 is connected to the unloading port of the conveying device, and the lower end of the unloading chute 1 3 is connected to the feeding port above the kiln head device 9; the upper end of the unloading chute 2 15 is connected to the discharge port below the kiln tail device 13, and the lower end of the unloading chute 2 15 is connected to the decomposition furnace 1, and a gate valve 4 14 is installed on the unloading chute 2 15; one end of the bypass air duct 7 is led out from the tertiary air duct 16, and the other end of the bypass air duct 7 is connected to the kiln head device 9 On the right side, a gate valve three 8 is installed on the bypass air duct 7; a gate valve five 16.1 is installed on the tertiary air duct 16, wherein the gate valve five 16.1 is located between the bypass air duct 7 and the decomposition furnace 1, and the lower end of the decomposition furnace 1 is connected to the inlet of one end of the No. 2 rotary kiln 17, and the other end of the No. 2 rotary kiln 17 is connected to the grate cooler 18, and the grate cooler 18 is also connected to one end of the tertiary air duct 16, and the other end of the tertiary air duct 16 is connected to the decomposition furnace 1.

[0032] The No. 1 rotary kiln 2 consists of a cylinder 2-7, a plurality of lifting plates and a material blocking plate 2-6. On the inner wall of the cylinder 2-7 near the kiln head device 9, a lifting plate 2-5 is arranged along the axial direction of the cylinder 2-7. The plurality of lifting plates 2-5 are evenly distributed in parallel along the circumference of the cylinder 2-7. The lifting plates 2-5 all protrude inwardly. Eight material blocking plates 2-6 are respectively arranged between every two lifting plates 2-5, dividing the interior of the cylinder 2-7 into two areas. The area near the kiln head device 9 is a drying pre-combustion area A, and the area near the kiln tail device 13 is a main combustion area B.

[0033] Furthermore, the height of the second lifting plate 2-5 protruding inward is 300mm, and the width of the second lifting plate 2-5 is 100mm; in the drying pre-combustion zone A, there are material blocking plates 2-6 evenly distributed alternately between every two lifting plates 2-5, and the material blocking plates 2.6 protrude inwardly by a height of 300mm.

[0034] Furthermore, on the inner wall of the cylinder 2-7, near the kiln tail device 13, a lifting plate 2-1 is provided along the axial direction of the cylinder 2-7, and twenty-four lifting plates 2-1 are evenly distributed in parallel along the circumference of the cylinder 2-7 and all protrude inwardly, with a protruding height of 100mm and a width of 50mm.

[0035] During production, the conveying device used in this system can use the metering and conveying device 4 independently developed by our company. At present, the metering and conveying device 4 has obtained patent authorization, announcement number: CN220165246U; the gate valve 4 14 is in the open state, and the alternative fuel enters the metering and conveying device 4 through the upstream feeding system. The metering and conveying device 4 is equipped with a metering device, which can automatically realize accurate metering and conveying of materials according to the set feeding amount. The feeding amount of the alternative fuel can be conveniently set on the central control screen as needed. The alternative fuel enters the discharge chute 1 3 from the discharge port of the metering and conveying device 4, and the material falls directly onto the gate of the gate valve 1 5. After the material accumulates to the set amount, the gate of the gate valve 1 5 opens, and the material falls directly onto the gate of the gate valve 2 6, and then the gate valve 1 5 is closed, and then the gate valve 2 6 is opened. The gate valve 1 5 and the gate valve 2 6 are opened and closed in sequence, and at least one gate valve is guaranteed to be closed to prevent cold air from entering the No. 1 rotary kiln 2; the material is directly fed into the rotary kiln 2 through the feed port of the kiln head device 9. Entering into the drying and pre-combustion zone A of the operating No. 1 rotary kiln 2, the lifting plates 2-5 in the drying and pre-combustion zone A in the No. 1 rotary kiln 2 lift and scatter the materials, and the lifted materials fully contact with the high-temperature air entering from the bypass air duct 7, quickly dry the moisture and preliminarily burn; the blocking plates 2-6 in the drying and pre-combustion zone A can further prolong the residence time of the materials in this area without completely blocking the advancement of the materials, so that the materials are more evenly distributed in the drying and pre-combustion zone A, which is more conducive to the drying and combustion of the materials. Under the continuous movement of the No. 1 rotary kiln 2, the materials in the drying pre-combustion zone A gradually move to the main combustion zone B. The distribution of the lifting plate 1 2-1 in the main combustion zone B is more dense, and the height of the inward protrusion is lower than that of the lifting plate 2-5, so that the combustion materials can be lifted and dispersed more evenly, and the materials are prevented from accumulating in the local area. The scattered materials are fully mixed with the oxygen in the high-temperature wind, so that the materials are burned quickly and violently. Even if the materials with slow combustion speed pass through the main combustion zone, there will be no large particles of materials, and the materials generated after entering the decomposition furnace 1 will not directly enter the No. 2 rotary kiln 17, or the material "afterburning" phenomenon will be eliminated, so as to ensure the stability of the entire system. The burning ash and the unburned small particles enter the decomposition furnace 1 through the unloading chute 2 15 under the movement of the No. 1 rotary kiln 2, and the unburned small particles continue to burn out in the decomposition furnace 1, and all the ash becomes part of the clinker.

[0036] During the production process, the opening of the gate valve 5 16-1 on the tertiary air duct 16 and the gate valve 3 8 on the bypass air duct 7 can be adjusted according to the usage of the alternative fuel to adjust the air intake into the No. 1 rotary kiln 2. When the alternative fuel is stopped or the related equipment of the No. 1 rotary kiln 2 is overhauled, the gate valve 3 8 and the gate valve 4 14 need to be closed and the opening of the gate valve 16.1 needs to be adjusted so as not to affect the normal production of the cement production line.

[0037] The above shows and describes the basic principle and main features of the utility model and the advantages of the utility model. Those skilled in the art should understand that the utility model is not limited by the above embodiments. The above embodiments and descriptions are only for explaining the principle of the utility model. Without departing from the spirit and scope of the utility model, the utility model may have various changes and improvements, which fall within the scope of the utility model to be protected. The scope of protection of the utility model is defined by the attached claims and their equivalents.

Claims

1. An alternative fuel auxiliary incineration system for a cement kiln, characterized in that: It comprises a rotary kiln, a decomposition furnace and an air duct; the rotary kiln comprises a No. 1 rotary kiln and a No. 2 rotary kiln respectively, the No. 1 rotary kiln has an inclination angle in the horizontal direction, the two ends of the No. 1 rotary kiln are respectively a kiln head device and a kiln tail device, the kiln head device is respectively connected to a conveying device and an air duct, the kiln tail device is connected to the decomposition furnace, the lower end of the decomposition furnace is connected to the entrance of one end of the No. 2 rotary kiln, the other end of the No. 2 rotary kiln is connected to a grate cooler, and the grate cooler is also connected to the air duct; the air duct comprises a bypass air duct and a tertiary air duct, one end of the bypass air duct is connected to the kiln head device, and the other end is connected to the tertiary air duct, one end of the tertiary air duct is connected to the grate cooler, and the other end is connected to the decomposition furnace; The No. 1 rotary kiln consists of a cylinder, a lifting plate and a material blocking plate. A lifting plate is arranged on the inner wall of the cylinder near the kiln head device along the axial direction of the cylinder. Multiple lifting plates are evenly distributed in parallel along the circumference of the cylinder. The lifting plates all protrude inwardly. A material blocking plate is arranged between every two lifting plates, dividing the interior of the cylinder into two areas. The area near the kiln head device is a drying and pre-combustion area, and the area near the kiln tail device is a main combustion area.

2. The alternative fuel auxiliary incineration system for cement kiln according to claim 1, characterized in that: Each of the material blocking plates is connected to two adjacent parallel material lifting plates, and the plurality of material blocking plates are located at different positions, so as to divide the drying and pre-combustion zone into a plurality of semi-enclosed areas of different sizes.

3. The alternative fuel auxiliary incineration system for cement kiln according to claim 1, characterized in that: On the inner wall of the cylinder, near the kiln tail device, a lifting plate is provided along the axial direction of the cylinder. A plurality of lifting plates are evenly distributed in parallel along the circumference of the cylinder, and all the lifting plates protrude inwards.

4. The alternative fuel auxiliary incineration system for cement kiln according to claim 1, characterized in that: A gate valve is provided on the bypass air duct, and another gate valve is provided on the tertiary air duct.

5. The alternative fuel auxiliary incineration system for cement kiln according to claim 1, characterized in that: The kiln head device is connected to the conveying device through a first material discharge chute, and two gate valves are respectively provided on the first material discharge chute; the kiln tail device is connected to the decomposition furnace through a second material discharge chute, and a gate valve is also provided on the second material discharge chute.

6. The alternative fuel auxiliary incineration system for cement kiln according to claim 1, characterized in that: A tugboat device is provided below the No. 1 rotary kiln, and the tugboat device lifts the No. 1 rotary kiln and forms an angle of 3° to 12° with the horizontal direction. The No. 1 rotary kiln performs a rotary motion on the tugboat device through a connected driving device.

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