System for calcining cement clinker by using cow dung as fuel
By designing a cow dung fuel system for cement clinker calcination, the problems of high carbon emissions and cow dung treatment in the cement industry are solved, and the energy-saving and carbon reduction effects of coal-fired substitution and cement production are achieved.
Patent Information
- Application Number
- CN202421414183.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-20
- Publication Date
- 2025-05-13
- Estimated Expiration
- 2034-06-20
AI Technical Summary
The fuel combination in the cement industry is carbon-intensive, resulting in high carbon emissions. As a potential alternative fuel, cow dung has problems such as high transportation costs, large water content and difficulty in dehydration treatment, and has not been effectively used in cement clinker calcination.
A system for calcining cement clinker using cow dung as fuel is designed, including a cow dung pretreatment device and a combustion furnace. After the cow dung is dried, crushed and transported, it is designed in the combustion furnace through parallel design on the kiln head side of the three-way air duct, and uses the oxygen and heat of the three-way air to burn to replace the combustion of raw coal. The burned furnace ash is collected and mixed with clinker to use as a mixture for cement production.
Coal-fired replacement has been achieved, energy efficiency and environmental protection effect of cement production have been improved, CO2 emissions and coal procurement costs have been reduced, and environmental pollution problems caused by cow dung accumulation have been solved.
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Figure CN222865575U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of cement production, in particular to a system using cow dung as fuel for calcining cement clinker. Background Art
[0002] The cement industry is energy-intensive, with energy costs typically accounting for 30%-40% of production costs. The industry's fuel mix is carbon-intensive, and the cement industry contributes 5% of global carbon emissions (IEA, 1999). Improving energy efficiency, using cement blends, and using waste as an alternative fuel can help reduce emissions.
[0003] The use of alternative fuels in the cement industry began in the 1980s. These alternative fuels are mainly composed of light components formed by mechanical or air separation from used tires, garbage, sewage sludge and solid fuels recovered from industrial waste. The use of alternative fuels requires adaptation to the combustion process. Modern multi-channel burners with temperature control systems can control the flame shape and optimize the combustion performance of the fuel and the combustion conditions of the clinker. In recent years, the industry has been very mature in the research and application of derivative fuels such as urban garbage, tires, and sludge, and has achieved good economic and social benefits.
[0004] Cow dung is the excrement of cattle. It has a high water content (50%-60%) and a high sand content. It is difficult to dehydrate. The dry basis cow dung has a low bulk density (0.25-0.35). The unit calorific value is about 3-4 times that of coal. The transportation cost or delivery volume is higher than that of coal and it is difficult to collect. Few people have studied its use as an alternative to industrial fuel. At present, it is mainly used in small-scale applications such as biogas, composting, and earthworm farming. Some centralized breeding sites even directly discard it, causing environmental pollution. There is no precedent for the skilled calcination of cow dung for cement. Utility Model Content
[0005] In order to solve the above technical problems, the utility model provides a system for calcining cement clinker using cow dung as fuel. The cow dung is dried and used for calcining cement clinker, thereby replacing coal. The calorific value of the dried cow dung can reach 3500Kcal / kg. It burns quickly, has a short burnout time, stable combustion, and a high flame temperature, thereby achieving the purpose of comprehensive treatment of cow dung and energy saving and carbon reduction in cement production.
[0006] To achieve this technical purpose, the utility model adopts the following scheme:
[0007] A system for calcining cement clinker using cow dung as fuel comprises a cow dung pretreatment device and a combustion furnace, wherein the combustion furnace is arranged at one side of a tertiary air duct kiln head, the tertiary air duct is connected to a decomposition furnace, a belt conveyor is arranged at a material outlet of the cow dung pretreatment device, a raw material bin is arranged at the material outlet end of the belt conveyor, the raw material bin is connected to the combustion furnace, and a belt scale is arranged between the raw material bin and the combustion furnace; the combustion furnace comprises an upper combustion chamber and a lower ash collecting chamber, an air distribution chamber is arranged between the combustion chamber and the ash collecting chamber, an air inlet pipe of the air distribution chamber is connected to the tertiary air duct, an air outlet pipe is arranged at the upper part of the combustion chamber, and the air outlet pipe is connected to the tertiary air duct.
[0008] Compared with the prior art, the beneficial effects of the utility model are:
[0009] The utility model dries cow dung and uses it for cement kiln clinker calcination, thereby replacing coal; the cow dung is transported by a large-angle belt conveyor; the combustion furnace adopts a double-layer design and is placed on the kiln head side of the tertiary air duct and connected in parallel with the tertiary air duct, and the tertiary air's own oxygen and heat are used to burn the cow dung, thereby increasing the tertiary air temperature, thereby replacing raw coal, achieving comprehensive cow dung treatment, and achieving the purpose of energy saving and carbon reduction in cement production.
[0010] Furthermore, the cow dung pretreatment device includes an upper hopper, the upper hopper is connected to a feeder, the feeder is connected to a crusher, a belt conveyor is arranged at the discharge port of the crusher, and the cow dung pretreatment device is equipped with a first dust collector. The feeder is a plate feeder, the crusher is a double-roll crusher, and the cow dung is crushed by a double-roll crusher, which can effectively crush stones and branches in the cow dung. The first dust collector collects dust to reduce environmental pollution.
[0011] Furthermore, the belt conveyor and the raw material bin are equipped with a second dust collector to collect dust and reduce environmental pollution.
[0012] Furthermore, the raw material bin is a double bin or multi-bin bin, and the discharge port of the raw material bin is provided with a clearing device. The raw material bin adopts a double bin or multi-bin design and is equipped with a clearing device, which can effectively solve the problem of easy arching and blocking due to the light weight of cow dung, and ensure continuous material discharge.
[0013] Furthermore, a feeding reamer is provided at the discharge port of the ash collection chamber, and the outlet of the feeding reamer is connected to the grate cooler, and an air locking device is provided at the outlet end of the feeding reamer. The ash collected in the ash collection chamber is sent to the end of the grate cooler through the feeding reamer, and mixed with the clinker as a mixed material for cement production and used for cement batching. The air locking device adopts a flap air locking device to avoid air leakage inside the system. The design of ash entering the grate cooler solves the problem of ash post-treatment, and also solves the problem that some fuel substitution designs directly feed alternative fuels into the decomposition furnace, causing ash to be brought in and affect the clinker batching.
[0014] Furthermore, gate valves are provided on the discharge port, air inlet pipe, air outlet pipe and tertiary air duct of the raw material warehouse to effectively control the supply of materials.
[0015] Furthermore, the system adopts the DCS centralized control mode, and all equipment signals are connected to the central control room and integrated into the DCS control system to achieve automated control. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 This is a schematic diagram of a system for calcining cement clinker using cow dung as fuel according to the utility model;
[0017] The markings in the figure are: 1. upper hopper; 2. feeder; 3. crusher; 4. first dust collector; 5. belt conveyor; 6. second dust collector; 7. raw material bin; 8. clearing device; 9. gate valve; 10. belt scale; 11. combustion chamber; 12. air distribution chamber; 13. ash collection chamber; 14. feeding reamer; 15. air locking device; 16. decomposition furnace; 17. tertiary air duct; 18. kiln head. DETAILED DESCRIPTION
[0018] In order to fully understand the purpose, features and effects of the present invention, the present invention is described in detail through the following specific implementation methods, but the present invention is not limited thereto.
[0019] See also Figure 1The utility model provides a system for calcining cement clinker using cow dung as fuel, including a cow dung pretreatment device and a combustion furnace. The cow dung pretreatment device includes an upper hopper 1, which is connected to a feeder 2, which is a plate feeder, and is connected to a crusher 3, which is a double-roll crusher, which can effectively crush stones and branches in the cow dung. A belt conveyor 5 is provided at the discharge port of the crusher 3, and the belt conveyor 5 is a large-angle belt. The cow dung pretreatment device is equipped with a first dust collector 4 to collect dust and reduce environmental pollution. A raw material bin 7 is provided at the discharge end of the belt conveyor 5, and a second dust collector 6 is provided for the belt conveyor 5 and the raw material bin 7 to collect dust and reduce environmental pollution. The raw material bin 7 is a double-bin bin or a multi-bin bin, and a clearing device 8 is provided at the discharge port of the raw material bin 7, which can effectively solve the problem of easy arching and blocking of materials due to cow dung, and ensure continuous material discharge. The raw material bin 7 is connected to the combustion furnace, and a belt scale 10 is arranged between the raw material bin 7 and the combustion furnace; the combustion furnace includes an upper combustion chamber 11 and a lower ash collection chamber 13, and an air distribution chamber 12 is arranged between the combustion chamber 11 and the ash collection chamber 13. The combustion furnace is arranged on one side of the kiln head 18 of the tertiary air duct 17, and the air inlet pipe of the air distribution chamber 12 is connected to the tertiary air duct 17. An air outlet pipe is arranged on the upper part of the combustion chamber 11, and the air outlet pipe is connected to the tertiary air duct 17, and the tertiary air duct 17 is connected to the decomposition furnace 16. A feeding reamer 14 is arranged at the discharge port of the ash collection chamber 13, and a wind locking device 15 is arranged at the outlet end of the feeding reamer 14. The ash collected in the ash collection chamber 13 is sent to the end of the grate cooler through the feeding reamer 14, and mixed with the clinker as a mixed material for cement production and used for cement batching. The wind locking device 15 adopts a flap wind locking device to avoid air leakage inside the system. The design of feeding ash into grate cooler solves the problem of ash post-treatment, and also solves the problem that some fuel substitution designs directly feed alternative fuels into the decomposition furnace 16, causing ash to be brought in and affect the clinker batching.
[0020] Gate valves 9 are provided on the discharge port, air inlet pipe, air outlet pipe and tertiary air duct 17 of the raw material warehouse 7. The system adopts the DCS centralized control mode, and the equipment signals are connected to the central control room and incorporated into the DCS control system to realize automatic control.
[0021] The working principle of the system of the utility model using cow dung as fuel for calcining cement clinker is as follows: the cow dung is naturally dried at the collection site, the moisture content is controlled within 10%, a cow dung storage shed and a cow dung pretreatment device are established in a suitable area near the kiln head 18 of the cement plant, the cow dung is sent to the feeder 2 by a forklift, the feeder 2 transports the cow dung to the crusher 3, the cow dung is crushed into small pieces less than 1 cm, and the first dust collector 4 collects the dust from the pretreatment device; the crushed cow dung is transported to the raw material bin 7 via the belt conveyor 5, the cow dung is fed into the combustion furnace via the belt scale 10, and the clearing device 8 is started when the raw material bin 7 is full of material to ensure continuous material discharge; the combustion furnace is arranged on one side of the kiln head 18 of the tertiary air duct 17, and is connected in parallel with the tertiary air duct 17, and the combustion furnace is designed in a double layer, the upper layer The combustion chamber 11 is the combustion chamber, and the lower layer is the ash collection chamber 13. The air distribution chamber 12 is set between the upper and lower chambers to separate the two chambers. Part of the hot air from the tertiary air duct 17 enters the combustion chamber 11, and the cow dung is burned by the oxygen and heat source of the tertiary air. The heat generated by the combustion of the cow dung raises the temperature of this part of the gas. The high-temperature gas then merges with the original tertiary air. The temperature of this part of the gas can reach above 1300℃ and enter the decomposition furnace 16, so as to increase the temperature of the decomposition furnace 16 and reduce the amount of coal used in the decomposition furnace 16, thus realizing the replacement of cow dung with coal; the ash collected in the ash collection chamber 13 is sent to the end of the grate cooler through the feeding reamer 14, and mixed with the clinker as a mixed material for cement production for cement batching. The joint of the feeding reamer 14 and the grate cooler adopts a flap lock air device 15 to avoid air leakage inside the system. The system control adopts the DCS centralized control mode, and the signals of the equipment used are connected to the central control room and incorporated into the original DCS control system to realize automatic control.
[0022] The utility model scheme realizes the application of cow dung in cement clinker calcination, which is a major breakthrough in the industrial application of cow dung. The system cleverly places the combustion furnace on the kiln head 18 side of the tertiary air duct 17, and makes full use of the oxygen and heat of the tertiary air to burn the cow dung. The heat emitted by the cow dung increases the temperature of the tertiary air and enters the decomposition furnace 16, which increases the furnace temperature and reduces the use of coal. The ash directly enters the grate cooler and is used as a mixed material for cement production, reducing the processing cost of the ash. The utility model can achieve a furnace coal replacement rate of 40%. Taking a 3200t / d cement kiln as an example, it can replace 40,000 tons of coal per year and reduce CO2 emissions by 70,000 tons. The current 5000 kcal raw coal is 750 yuan / ton at the local price, and the dry cow dung is 250 yuan / ton (local price). The annual coal procurement cost can be reduced by 9 million yuan, and carbon trading can create a value of 7 million yuan. The comprehensive annual economic benefit is 16 million yuan, and it can effectively solve the environmental pollution problem caused by the accumulation of cow dung.
[0023] Finally, it should be noted that the above-listed examples are only preferred embodiments of the present invention. Of course, those skilled in the art can make changes and modifications to the present invention. If these modifications and modifications fall within the scope of the claims of the present invention and their equivalent technologies, they should be considered to be within the scope of protection of the present invention.
Claims
1. A system for calcining cement clinker using cow dung as fuel, comprising a cow dung pretreatment device and a combustion furnace, wherein the combustion furnace is arranged on one side of a tertiary air duct (17) and a kiln head (18), and the tertiary air duct (17) is connected to a decomposition furnace (16), characterized in that: A belt conveyor (5) is arranged at the discharge port of the cow dung pretreatment device, a raw material bin (7) is arranged at the discharge end of the belt conveyor (5), the raw material bin (7) is connected to a combustion furnace, and a belt scale (10) is arranged between the raw material bin (7) and the combustion furnace; the combustion furnace comprises an upper combustion chamber (11) and a lower ash collection chamber (13), an air distribution chamber (12) is arranged between the combustion chamber (11) and the ash collection chamber (13), an air inlet pipe of the air distribution chamber (12) is connected to a tertiary air pipe (17), an air outlet pipe is arranged on the upper part of the combustion chamber (11), and the air outlet pipe is connected to the tertiary air pipe (17).
2. The system for calcining cement clinker using cow dung as fuel according to claim 1, characterized in that: The cow dung pretreatment device comprises an upper hopper (1), the upper hopper (1) is connected to a feeder (2), the feeder (2) is connected to a crusher (3), a belt conveyor (5) is arranged at the discharge port of the crusher (3), and the cow dung pretreatment device is equipped with a first dust collector (4).
3. The system for calcining cement clinker using cow dung as fuel according to claim 1, characterized in that: The belt conveyor (5) and the raw material bin (7) are equipped with a second dust collector (6).
4. The system for calcining cement clinker using cow dung as fuel according to claim 1, characterized in that: The raw material bin (7) is a double bin or a multi-bin bin, and a clearing device (8) is provided at the discharge port of the raw material bin (7).
5. The system for calcining cement clinker using cow dung as fuel according to claim 1, characterized in that: A feeding reamer (14) is provided at the discharge port of the ash collecting chamber (13), the outlet of the feeding reamer (14) is connected to a grate cooler, and an air locking device (15) is provided at the outlet end of the feeding reamer (14).
6. The system for calcining cement clinker using cow dung as fuel according to claim 1, characterized in that: Gate valves (9) are provided on the material outlet, air inlet pipe, air outlet pipe and tertiary air pipe (17) of the raw material bin (7).