Clay calcining processing system
By designing a clay calcination treatment system, using multi-stage preheating and heat exchange technology to treat inert waste gas, the problems of exhaust gas emissions and product color control in clay calcination are solved, and the waste gas treatment effect with low cost, low heat consumption and environmental protection is achieved.
Patent Information
- Application Number
- CN202411317537.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-20
- Publication Date
- 2024-12-27
- Estimated Expiration
- 2044-09-20
AI Technical Summary
During the clay calcination process, how to control the color of the product and economically handle exhaust gas emissions, especially because the clay contains harmful components to be discharged into the atmosphere at high temperatures.
A clay calcination treatment system is designed, including raw material mills, dust collectors, calcination preheating system, cooling system, harmless waste gas treatment system and exhaust gas recycling system. By controlling the oxygen input volume, using a multi-stage preheating cyclone and The heat exchanger maintains a reducing atmosphere, treats CO, volatile organic compounds and sulfides in the inert exhaust gas, achieves the emission of exhaust gas to meet standards, and reduces external air consumption through recycling.
The color control of the finished product is achieved, the system pressure loss and heat consumption are reduced, the treatment cost is significantly reduced, the external air consumption is reduced, and the goal of economical and environmental protection is achieved.
Smart Images
Figure CN118816550B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of calcination technology, in particular to a clay calcination processing system. Background Art
[0002] Due to its own characteristics, clay calcination technology does not produce carbon dioxide during calcination. Only fuel forms waste gas. Compared with ordinary cement clinker, it can reduce carbon dioxide emissions by 40%. Therefore, clay calcination technology is increasingly being promoted and applied. However, due to the diversity of clay, it contains many elements, especially iron, which will be oxidized to red during combustion, which is different from traditional cement ash. Therefore, the production process needs to be controlled to ensure that the product is gray-black. In addition, clay contains various harmful components, which will be discharged into the atmosphere during high-temperature processes and need to be processed. Therefore, how to control the product color and economically treat waste gas emissions during the production process is a key and difficult problem in the research of this field. Summary of the invention
[0003] In order to control the product color and economically treat the waste gas generated in the clay calcining process, the present invention provides a clay calcining treatment system.
[0004] The present invention provides a clay calcination treatment system adopts the following technical solution:
[0005] A clay calcining treatment system comprises a raw material mill, a dust collector connected to the outlet of the raw material mill, a calcining preheating system and a smoke exhaust system connected to the outlet of the dust collector, a cooling system connected to the outlet of the calcining preheating system, a waste gas harmless treatment system for treating inert gas, and a waste gas recycling system; the calcining preheating system comprises a preheating cyclone, a decomposition furnace, a first hot blast furnace and a second fan for providing a heat source to the decomposition furnace; the cooling system comprises a cooling cyclone, and the waste gas harmless treatment system comprises a third fan and a second hot blast furnace; the waste gas recycling system comprises a first heat exchanger and a fourth fan; the inert waste gas generated in the decomposition furnace passes through a multi-stage preheating cyclone, a first heat exchanger, a fourth fan, and a cooling cyclone located at the first few stages, and then is input to the second hot blast furnace through the third fan, and the outlet of the second hot blast furnace is connected to the raw material mill.
[0006] By adopting the above technical scheme, CO, volatile organic compounds and sulfides in the inert waste gas are treated by the second hot blast furnace and raw material dust, so that the discharged waste gas meets the standards; by creatively utilizing the characteristics of the raw materials and controlling the oxygen input in the decomposition furnace to be lower than the amount required for combustion, the entire combustion process maintains a reducing atmosphere, ensuring that the finished product is gray-black; the entire clay calcination treatment system has low pressure loss, reduced system heat consumption, and meets the emission standards, which can significantly reduce the treatment cost and save optimization investment; the inert waste gas is cooled by the first heat exchanger and then transported to the first few stages of cooling cyclones for cooling, which can reduce the sulfide content in the inert waste gas on the one hand, and realize the recycling of the inert waste gas on the other hand, reduce the consumption of external clean air, and realize economic value.
[0007] Optionally, cold air is introduced into the cooling cyclones located in the latter stages, and the gas output by heat exchange enters the first hot air furnace through the second fan.
[0008] By adopting the above technical solution, the cold air can be used for the cooling process of the cooling system, and the gas after heat exchange can be transported to the first hot blast furnace for recycling, thereby improving the economy.
[0009] Optionally, the third fan is provided with two branches for outputting the inert gas, the first branch is connected to the second hot blast furnace, the second branch is connected to the cooling cyclone located at the first few stages, and the second branch is installed with a second heat exchanger.
[0010] By adopting the above technical solution and adding a branch with a second heat exchanger, the shortage of inert gas can be effectively compensated, so that a sufficient amount of inert gas can be introduced into the cooling system for cooling, thereby achieving higher economic value.
[0011] Optionally, the second heat exchanger is equipped with a fifth fan, and the heat exchange gas output by the second heat exchanger is transported to the raw material mill.
[0012] By adopting the above technical solution, the heat exchange air is connected to the whole system, thus achieving the airtight operation of the whole system.
[0013] Optionally, two branches are provided for the second hot blast furnace to output gas, the first branch is connected to the raw material mill, and the second branch is connected to the dust collector.
[0014] By adopting the above technical solution, if the moisture content of the clay is reduced, part of the high-temperature gas can be directly input into the dust collector to meet the diversified usage requirements according to the moisture content of the clay.
[0015] Optionally, the smoke exhaust system includes a first fan and a smoke exhaust tower.
[0016] By adopting the above technical solution, the effective discharge of exhaust gas is achieved.
[0017] Optionally, the finished product output end of the cooling system is provided with a conveying reamer for conveying the finished product to the storage system.
[0018] By adopting the above technical solution, effective output of finished products is achieved.
[0019] Optionally, the clay in the stockpile is transported to the raw mill by a conveyor belt.
[0020] By adopting the above technical solution, effective input of clay is achieved.
[0021] In summary, the present invention includes at least one of the following beneficial technical effects:
[0022] The CO, volatile organic compounds and sulfides in the inert waste gas are processed by the second hot blast furnace and raw material dust, so that the discharged waste gas meets the standards; creatively utilizing the raw material characteristics, by controlling the oxygen input in the decomposition furnace to be lower than the amount required for combustion, the entire combustion process maintains a reducing atmosphere, ensuring that the finished product is gray-black; the entire clay calcination treatment system has low pressure loss, reduced system heat consumption, and the exhaust gas meets the standards, which can significantly reduce the treatment cost and save optimization investment;
[0023] After being cooled by the first heat exchanger, the inert waste gas is transported to the first several stages of cooling cyclones for cooling. On the one hand, the sulfide content in the inert waste gas can be reduced. On the other hand, the inert waste gas can be recycled, the consumption of clean air from the outside can be reduced, and economic value can be achieved.
[0024] Adding a branch with a second heat exchanger can effectively make up for the shortage of inert gas, allowing sufficient inert gas to be introduced into the cooling system for cooling, thereby achieving higher economic value. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Figure 1 It is a structural schematic diagram of a clay calcining treatment system according to an embodiment of the present invention.
[0026] Explanation of the reference numerals: 1. raw material mill; 10. conveyor belt; 2. dust collector; 20. first fan; 21. smoke exhaust tower; 3. calcination preheating system; 30. first preheating cyclone; 31. second preheating cyclone; 32. decomposition furnace; 33. first hot blast furnace; 34. second fan; 35. third preheating cyclone; 4. cooling system; 40. first cooling cyclone; 41. second cooling cyclone; 42. third cooling cyclone; 43. fourth cooling cyclone; 5. conveying reamer; 6. waste gas harmless treatment system; 60. third fan; 61. second hot blast furnace; 7. waste gas recycling system; 70. first heat exchanger; 71. fourth fan; 72. second heat exchanger; 73. fifth fan. DETAILED DESCRIPTION
[0027] The following is combined with Figure 1 The present invention is described in further detail.
[0028] The embodiment of the present invention discloses a clay calcining treatment system. Figure 1 The clay calcination processing system includes a raw material mill 1, a dust collector 2, a calcination preheating system 3, a cooling system 4, a conveying reamer 5, a waste gas harmless treatment system 6 and a waste gas recycling system 7. This system is particularly suitable for processing clay with high moisture content and iron content with a moisture content higher than 20%.
[0029] Reference Figure 1 , the clay is transported from the pile shed to the raw material mill 1 via the conveyor belt 10 for drying and grinding. The dust collector 2 is connected to the raw material mill 1, and is used to separate the finished product from the waste gas after grinding, wherein the finished product is fed into the calcination preheating system 3, and the waste gas is discharged through the smoke exhaust system. The calcination preheating system 3 includes a primary preheating cyclone 30, a secondary preheating cyclone 31, a decomposition furnace 32, a first hot blast furnace 33, a second fan 34 and a tertiary preheating cyclone 35. There are two primary preheating cyclones 30, and the finished product output from the dust collector 2 is first fed into two primary preheating cyclones 30 for heating, then enters the secondary preheating cyclone 31 for heating again, and then enters the decomposition furnace 32 for high-temperature calcination and dehydroxylation.
[0030] Reference Figure 1 In order to prevent iron from being oxidized at high temperature, a reducing atmosphere must be maintained in the decomposition furnace 32, and the amount of air supplied to the fuel during the combustion process must be controlled to be less than the amount required for complete combustion of the fuel, so that a reducing atmosphere of CO and H2 is formed in the decomposition furnace 32, and Fe2O3 is reduced to Fe3O4 at high temperature, thereby maintaining the finished product in a gray-black color, but at the same time, volatile organic compounds and sulfides are generated. The heat source of the decomposition furnace 32 is provided by the first hot blast furnace 33, and the first hot blast furnace 33 is connected to a second blower 34 for conveying gas. The calcined finished product finally enters the three-stage preheating cyclone 35 for collection.
[0031] Reference Figure 1 The cooling system 4 is connected to the calcination preheating system 3 as the next process for cooling the high-temperature finished product. The cooling system 4 includes a primary cooling cyclone 40, a secondary cooling cyclone 41, a tertiary cooling cyclone 42 and a quaternary cooling cyclone 43. The high-temperature finished product output from the tertiary preheating cyclone 35 is first fed into the primary cooling cyclone 40, and then enters the secondary cooling cyclone 41, the tertiary cooling cyclone 42 and the quaternary cooling cyclone 43 in sequence for step-by-step cooling. The cooled finished product is finally output to the storage system through the conveying reamer 5.
[0032] Reference Figure 1The waste gas harmless treatment system 6 and the waste gas recycling system 7 cooperate with each other. The waste gas harmless treatment system 6 includes a third fan 60 and a second hot air furnace 61, and the waste gas recycling system 7 includes a first heat exchanger 70, a fourth fan 71, a second heat exchanger 72 and a fifth fan 73.
[0033] Reference Figure 1 The cold air acting on the cooling system 4 enters the fourth-stage cooling cyclone 43 and the third-stage cooling cyclone 42 in turn. At this time, the output temperature of the gas is as high as 220°C. The gas is input into the first hot blast furnace 33 through the second fan 34 for recycling and use for combustion. The inert waste gas output by the decomposition furnace 32 has a temperature of up to 850°C and a very low oxygen content. The oxygen content of the inert waste gas output by the calcination preheating system 3 is less than 0.5%. The inert waste gas passes through the third-stage preheating cyclone 35, the second-stage preheating cyclone 31 and the first-stage preheating cyclone 30 in turn to preheat the finished product.
[0034] Reference Figure 1 , the temperature of the inert waste gas after being output from the first-stage preheating cyclone 30 drops to 250°C, and then the inert waste gas enters the first heat exchanger 70 and the fourth fan 71. At this time, the output temperature of the inert waste gas further drops to 120°C, and the inert waste gas is then input into the second-stage cooling cyclone 41 to rapidly cool the finished product, ensuring that the finished product is not oxidized during the cooling process and remains in the form of a magnet. The temperature of the inert waste gas after being output from the second-stage cooling cyclone 41 rises to 260°C, and the inert waste gas is then input into the first-stage cooling cyclone 40, and the temperature after being output from the first-stage cooling cyclone 40 further rises to 490°C. The entire cooling system 4 also requires a high system sealing performance to ensure that the oxygen content of the inert waste gas output from the first-stage cooling cyclone 40 is less than 2%, and some volatile organic compounds in the inert gas are removed by the high-temperature finished product.
[0035] Reference Figure 1 At this time, the inert waste gas is transported to the second hot blast furnace 61 through the third fan 60 for high-temperature treatment. The treated gas is output from the second hot blast furnace 61 and its temperature rises to 850°C and is used as a drying heat source for the raw material mill 1. The temperature of the second hot blast furnace 61 is adaptively adjusted according to the moisture content of the clay, and the two are positively correlated. On the one hand, the second hot blast furnace 61 converts the inert waste gas into the heat source required for drying the clay and inputs it into the raw material mill 1. On the other hand, it performs high-temperature treatment on the CO and volatile organic compounds contained in the inert waste gas to avoid air pollution, without the need to set up an RTO system (regenerative thermal oxidation incineration system) to eliminate organic matter, saving treatment costs.
[0036] Reference Figure 1The treated gas still contains sulfide, which is adsorbed by the raw material dust when passing through the raw material mill 1 and the dust collector 2 and re-enters the system, so that the treated gas meets the emission standards. The gas is finally discharged into the atmosphere through the exhaust system composed of the first fan 20 and the exhaust tower 21. If the water content in the clay is low, a large amount of high-temperature gas is not needed at this time, and another branch can be introduced to directly transport part of the gas output from the second hot air furnace 61 to the dust collector 2.
[0037] Reference Figure 1 In order to make up for the insufficient exhaust gas output by the calcination preheating system 3, a second heat exchanger 72 and a fifth fan 73 are provided in this embodiment. The inert exhaust gas output by the third fan 60 is divided into two branches, one of which is introduced into the second hot blast furnace 61, and the other is introduced into the second heat exchanger 72. The fifth fan 73 acts on the second heat exchanger 72 for heat exchange. The temperature of the inert exhaust gas output by the second heat exchanger 72 drops to 120°C. This part of the inert exhaust gas intersects with the inert exhaust gas output by the fourth fan 71 and enters the secondary cooling cyclone 41. The heat exchange gas is heated to 260°C and is input into the raw material mill 1 together with the gas output by the second hot blast furnace 61.
[0038] In this clay calcination treatment system, CO, volatile organic compounds and sulfides in the inert waste gas are digested and absorbed by the system, reducing air pollution. During the calcination process of clay, the organic matter contained in its raw materials will volatilize during the preheating process. At the same time, in order to control the color, the entire calcination process needs to maintain a reducing atmosphere. The inert waste gas output by the calcination preheating system 3 contains a large amount of CO, and the fuel contains a large amount of sulfur. If these inert waste gases are to be treated separately, huge costs need to be invested. This system can perfectly adapt to the high-humidity clay calcination process, significantly reduce the investment cost of inert waste gas treatment, and meet gas emission standards at the same time.
[0039] The whole clay calcining treatment system has low pressure loss and can reduce system heat consumption. The finished product after clay calcining can partially replace traditional cement clinker, achieving the purpose of energy saving and emission reduction. This system creatively combines the control requirements required in the whole clay calcining process, and utilizes the characteristics of raw materials to save and optimize investment.
[0040] The above are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.
Claims
1. A clay calcination treatment system, characterized in that: The invention comprises a raw material mill (1), a dust collector (2) connected to the outlet of the raw material mill (1), a calcination preheating system (3) and a smoke exhaust system connected to the outlet of the dust collector (2), a cooling system (4) connected to the outlet of the calcination preheating system (3), a waste gas harmless treatment system (6) for treating inert gas, and a waste gas recycling system (7); the calcination preheating system (3) comprises a preheating cyclone, a decomposition furnace (32), a first hot blast furnace (33) and a second fan (34) for providing a heat source to the decomposition furnace (32); the cooling system (4) comprises a cooling cyclone, and the waste gas harmless treatment system (6) comprises a third fan (60) and a second hot blast furnace (61); the waste gas recycling system (7) comprises a first heat exchanger (70) and a fourth fan (71); the inert exhaust gas generated in the decomposition furnace (32) passes through a multi-stage preheating cyclone, a first heat exchanger (70), a fourth fan (71), and a cooling cyclone located at the first few stages, and is then input into the second hot blast furnace (61) through the third fan (60), and the outlet of the second hot blast furnace (61) is connected to the raw material mill (1); the third fan (60) is provided with two branches for outputting the inert gas, the first branch is connected to the second hot blast furnace (61), and the second branch is connected to the cooling cyclone located at the first few stages, and the second branch is installed with a second heat exchanger (72); the second heat exchanger (72) is matched with a fifth fan (73), and the heat exchange gas output by the second heat exchanger (72) is transported to the raw material mill (1).
2. The clay calcining treatment system according to claim 1, characterized in that: Cold air is introduced into the cooling cyclones located in the latter stages, and the gas output from the heat exchange enters the first hot air furnace (33) through the second fan (34).
3. The clay calcining treatment system according to claim 1 or 2, characterized in that: The second hot blast furnace (61) is provided with two branch lines for outputting gas, the first branch line is connected to the raw material mill (1), and the second branch line is connected to the dust collector (2).
4. The clay calcining treatment system according to claim 1, characterized in that: The smoke exhaust system comprises a first fan (20) and a smoke exhaust tower (21).
5. The clay calcining treatment system according to claim 1, characterized in that: The finished product output end of the cooling system (4) is provided with a conveying reamer (5) for conveying the finished product to the storage system.
6. The clay calcining treatment system according to claim 1, characterized in that: The clay in the stockpile is transported to the raw material mill (1) via a conveyor belt (10).