Coal gangue calcination and cement production coupling system
Through the coupling system of coal gangue calcination and cement production, and the use of technical means such as suspended calciner and preheating mechanism, the problem of difficult ignition and combustion of coal gangue is solved, and the energy-saving and carbon reduction effects of efficient energy utilization and cement production are achieved.
Patent Information
- Application Number
- CN202421144929.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-23
- Publication Date
- 2025-01-17
- Estimated Expiration
- 2034-05-23
AI Technical Summary
It is difficult to ignite coal gangue and it is difficult to maintain combustion in the early stages of combustion, resulting in difficult to establish a calcination system, waste of energy and poor cement performance.
A system is designed to couple coal gangue calcination and cement production. The coal gangue is ignited by using a suspended calciner, separator, preheating mechanism and cooling mechanism to separate the hot air and heat-raising air through the three-way air duct, and use the combustion energy. Preheat and cool, reduce energy waste and improve combustion efficiency.
It has achieved efficient calcination of coal gangue, improved energy utilization, reduced energy consumption and carbon emissions in cement production, and the system structure is simple, with a small footprint, and no additional exhaust purification equipment is required, which is in line with the goal of energy conservation and carbon reduction.
Smart Images
Figure CN222364384U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of cement production, and in particular to a system for coupling gangue calcination with cement production. Background Art
[0002] Gangue is solid waste discharged during coal mining. Using gangue in cement production is one of the main ways to achieve its large-scale utilization. Specifically, during the calcination process of gangue, clay minerals in it decompose to form active minerals of silicon and aluminum. Active minerals can participate in the reaction during cement hydration to make cement strong. Therefore, calcined gangue can replace part of cement clinker for cement production. Studies have shown that calcined gangue can replace 20% to 50% of cement clinker after appropriate batching without significantly reducing the performance of cement.
[0003] Although using coal gangue for cement production can make full use of coal gangue, two problems must be solved: one is to fully calcine and activate the clay minerals in the coal gangue to decompose and form active minerals of silicon and aluminum; the other is to fully burn the coal and organic matter in the coal gangue to eliminate their adverse effects on cement performance (high water demand, low strength, large amount of admixtures, etc.). However, it is very difficult to remove coal from coal gangue. The carbon content in coal gangue is low, and it contains high moisture, ash, sulfur and mineral components. In addition, the combustible substances in the gangue, such as sulfides, carbonaceous sediments, oil shale, residual coal, etc., which are mainly composed of C, H, S, etc., are irregularly distributed and morphologically in the gangue, and the particle shapes and sizes are also different, resulting in irregular gaps and pores in the gangue when it is piled up. These gaps and pores provide oxygen for the combustible substances during the combustion process, but due to their small volume, the combustible substances inside the gangue cannot fully contact and combine with oxygen. All of the above reasons make it difficult to ignite the gangue, and it is difficult to maintain combustion in the early stages of combustion. In order to ignite the gangue for combustion, a large amount of energy consumption is required, and it is difficult to establish a system for calcining the gangue, making it difficult to fully utilize the gangue.
[0004] Coal gangue has a certain calorific value, usually in the range of 600Cal / kg to 1000Cal / kg (2509J / kg to 4182J / kg). After the combustion of coal gangue, the energy released by itself cannot be reasonably utilized, resulting in energy waste. Utility Model Content
[0005] The embodiment of the present application provides a system for coupling coal gangue calcination with cement production, which can solve the problem that coal gangue is difficult to ignite and difficult to maintain combustion in the initial stage of combustion. In order to ignite coal gangue for combustion, a large amount of energy consumption is required, and it is difficult to establish a system for calcining coal gangue. After the coal gangue is burned, the energy released by itself cannot be reasonably utilized, resulting in energy waste.
[0006] In order to achieve the above purpose, the technical solution of the embodiment of the utility model is:
[0007] The embodiment of the utility model provides a system for coupling gangue calcination and cement production, including a suspended calcining furnace, a separator, a preheating mechanism, a cooling mechanism and a blasting mechanism;
[0008] The output port of the tertiary air duct of the cement kiln tail system and the output port of the blast mechanism are both connected to the input port of the suspension calciner, so that a part of the hot air separated by the tertiary air duct and the heated air after being blown by the blast mechanism ignite the heated coal gangue powder in the suspension calciner and suspend and heat it, and then gradually reduce the amount of the hot air introduced to obtain a high-temperature mixture, wherein the blast air volume is adapted to the pressure of the cement kiln tail system;
[0009] The output port of the suspension calcining furnace is connected to the input port of the separator, and the separator is configured to separate the high-temperature mixture into high-temperature calcined coal gangue and high-temperature calcined flue gas;
[0010] The gas output port of the separator is connected to the gas input port of the preheating mechanism so as to input the separated high-temperature calcination flue gas into the gas input port of the preheating mechanism;
[0011] The gas outlet of the preheating mechanism is connected to the gas inlet of the suspension preheater of the cement kiln tail system which is at the same pressure as the gas outlet of the preheating mechanism;
[0012] The air inlet pipe of the preheating mechanism inputs room temperature coal gangue powder and is heated by the high temperature calcination flue gas to obtain heated coal gangue powder and cooled calcination flue gas, the cooled calcination flue gas gradually heats the cement raw material, gradually cools itself and is discharged after being purified;
[0013] The solid output port of the separator is communicated with the air inlet pipe of the cooling mechanism to input the separated high-temperature calcined coal gangue into the air inlet pipe of the cooling mechanism;
[0014] Normal temperature air is input into the gas input port of the cooling mechanism and is heated by the high temperature calcined coal gangue to obtain the heated air, and the high temperature calcined coal gangue is cooled to obtain low temperature calcined coal gangue;
[0015] The gas outlet of the cooling mechanism is communicated with the gas inlet of the blowing mechanism, and the heated air is blown by the blowing mechanism and then input into the suspension calcining furnace.
[0016] In a possible implementation, the preheating mechanism includes a multi-stage preheater;
[0017] The room temperature coal gangue powder is input from the air inlet pipe of the first stage preheater, the discharge port of the upper stage preheater is connected with the air inlet pipe of the lower stage preheater, and the discharge port of the last stage preheater is connected with the bottom of the suspended calcining furnace;
[0018] The gas outlet of the separator is connected to the gas inlet of the last-stage preheater, the gas outlet of the next-stage preheater is connected to the gas inlet of the previous-stage preheater, and the gas outlet of the first-stage preheater is connected to the air flow inlet of the suspended preheater of the cement kiln tail system which is isobaric with the gas outlet of the preheating mechanism.
[0019] In a possible implementation, the preheating mechanism includes two stages of preheaters.
[0020] In a possible implementation, the cooling mechanism includes a multi-stage cooler;
[0021] The discharge port of the separator is connected to the air inlet pipe of the first-stage cooler, the high-temperature calcined coal gangue is input from the air inlet pipe of the first-stage cooler, the discharge port of the upper-stage cooler is connected to the air inlet pipe of the lower-stage cooler, and the discharge port of the last-stage cooler outputs the low-temperature calcined coal gangue;
[0022] Normal temperature air is input from the air inlet pipe of the last stage cooler, the gas outlet of the next stage cooler is connected with the gas inlet of the previous stage cooler, and the gas outlet of the first stage cooler is connected with the gas inlet of the blowing mechanism.
[0023] In a possible implementation, the cooling mechanism includes three stages of coolers.
[0024] One or more technical solutions provided in the embodiments of the present utility model have at least the following technical effects or advantages:
[0025] The system of coupling gangue calcination and cement production provided by the embodiment of the utility model can ignite the gangue in the suspended calcining furnace through a part of the hot air and heated air separated by the tertiary air duct, and maintain the combustion of the gangue powder. After the gangue is burned, the energy released by itself is used to heat the normal temperature gangue powder in the preheating mechanism, and is used to heat the normal temperature air in the cooling mechanism, and the heat energy of the cement kiln tail system is supplemented with the cooling calcination flue gas, which effectively solves the energy utilization, while reducing the disturbance during cement production, and can use the cement kiln tail system to dispose of gaseous pollutants and reduce pollutant emissions. The method has a simple process and a small structural footprint, which is convenient to implement in the form of an additional module on the suspended preheater of the cement kiln tail system, and does not require additional tail gas purification equipment investment. The matching problem of the two process flows is fully considered, the impact on the existing cement process is small, the energy utilization efficiency is high, and a self-balanced state can be achieved, no additional energy consumption is required, and it is very energy-saving. The calcined gangue product of the utility model can replace 30% to 40% of cement clinker, and the production process has low energy consumption and low carbon emission, and the goal of energy saving and carbon reduction in cement production is achieved while realizing the comprehensive utilization of gangue. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the description of the embodiments of the utility model will be briefly introduced below. Obviously, the drawings described below are some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0027] Figure 1 A schematic diagram of the structure of a system for coupling gangue calcination and cement production provided in an embodiment of the present application.
[0028] Icons: 1-coal gangue calcination and cement production coupling system; 11-suspended calciner; 12-separator; 13-preheating mechanism; 131-preheater; 14-cooling mechanism; 141-cooler; 15-blowing mechanism; 2-cement kiln tail system; 21-suspended preheater; 22-exhaust gas purification mechanism; 23-tertiary air duct. DETAILED DESCRIPTION
[0029] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0030] In the description of the embodiments of the present utility model, it should be noted that the orientations or positional relationships indicated by the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present utility model and simplifying the description, rather than indicating or implying that the system or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. The terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present utility model can be understood according to the specific circumstances.
[0031] like Figure 1 As shown, an embodiment of the utility model provides a system 1 for coupling gangue calcination and cement production, including a suspended calcining furnace 11, a separator 12, a preheating mechanism 13, a cooling mechanism 14 and a blasting mechanism 15.
[0032] The output port of the tertiary air duct 23 of the cement kiln tail system 2 and the output port of the blast mechanism 15 are both connected to the input port of the suspension calciner 11, so that a part of the hot air separated by the tertiary air duct 23 and the heated air after being blown by the blast mechanism 15 ignite and suspend and heat the heated coal gangue powder in the suspension calciner 11, and then gradually reduce the amount of hot air introduced to obtain a high-temperature mixture, wherein the blast air volume is adapted to the pressure of the cement kiln tail system 2. The input port of the suspension calciner 11 is located at the lower part of the suspension calciner 11. The blast mechanism 15 can be a high-temperature fan. Since the heated gas has a temperature of 500°C to 600°C, a high-temperature fan is used.
[0033] The blast air volume is adapted to the pressure of the cement kiln tail system 2. For example, if the negative pressure above the cement kiln tail system 2 is large, the pressure needs to be reduced, and the high-temperature fan speed needs to be increased to increase the blast air volume. If the negative pressure above the cement kiln tail system 2 is small, the pressure needs to be increased, and the high-temperature fan speed needs to be slowed down to reduce the blast air volume.
[0034] The output port of the suspension calciner 11 is connected to the input port of the separator 12 , and the separator 12 is configured to separate the high temperature mixture into high temperature calcined coal gangue and high temperature calcined flue gas. The output port of the suspension calciner 11 is located at the upper part of the suspension calciner 11 .
[0035] The gas output port of the separator 12 is connected to the gas input port of the preheating mechanism 13 so as to input the separated high-temperature calcination flue gas into the gas input port of the preheating mechanism 13 .
[0036] The gas outlet of the preheating mechanism 13 is communicated with the gas inlet of the suspension preheater 21 of the cement kiln tail system 2 at the same pressure as the gas outlet of the preheating mechanism 13 .
[0037] The relative resistance of the system 1 for coupling the gangue calcination and cement production is relatively small, while the resistance of the cement kiln tail system 2 is relatively large. If the two are combined, the pressure of the system 1 for coupling the gangue calcination and cement production will be forcibly increased, resulting in energy waste. For example, the cement kiln tail system 2 requires a pressure of -3000Mpa to operate. If the two are forcibly combined, the pressure may need to be raised to -7000Mpa to -6000Mpa. The gas outlet of the preheating mechanism 13 is connected to the airflow inlet of the suspended preheater 21 of the cement kiln tail system 2, which is at an equal pressure to the gas outlet of the preheating mechanism 13, so that both can operate normally. Figure 1 As shown, in practice, the commonly used cement kiln tail system 2 is a double series cyclone mechanism, each group of cyclone mechanisms includes a five-stage suspension preheater 21, and the air flow inlet of the third-stage suspension preheater C3A, C3B is the air flow inlet of the suspension preheater 21 where the gas output port of the preheating mechanism 13 is equal to the pressure. The cooling calcined flue gas output from the gas output port of the preheating mechanism gas of this system is divided into two paths, which are respectively connected to the air flow inlets of the third-stage suspension preheaters C3A, C3B in the cement kiln tail system 2.
[0038] The air inlet pipe of the preheating mechanism 13 inputs the normal temperature coal gangue powder and is heated by the high temperature calcination flue gas to obtain the heated coal gangue powder and the cooled calcination flue gas. The cooled calcination flue gas heats the cement raw material step by step, cools itself step by step and is discharged after being purified.
[0039] The solid output port of the separator 12 is communicated with the air inlet pipe of the cooling mechanism 14 so as to input the separated high-temperature calcined coal gangue into the air inlet pipe of the cooling mechanism 14 .
[0040] Normal temperature air is input into the gas input port of the cooling mechanism 14 and is heated by the high temperature calcined coal gangue to obtain heated air, and the high temperature calcined coal gangue is cooled to obtain low temperature calcined coal gangue.
[0041] The gas outlet of the cooling mechanism 14 is connected to the gas inlet of the blowing mechanism 15, and the heated air is blown by the blowing mechanism 15 and then input into the suspended calcining furnace 11. The blowing mechanism 15 is used to control the pressure balance of the entire system. If there is no blowing mechanism 15, the resistance drop of the system 1 coupling the gangue calcining and cement production will be very large, which will affect the kiln tail fan of the cement kiln tail system 2, thereby affecting the cement preparation process of the cement kiln tail system 2. The heated air is blown to the suspended calcining furnace 11 by the blowing mechanism 15, and then the separator 12 draws it out, which is equivalent to blowing and drawing. The negative pressure of the system 1 coupling the gangue calcining and cement production can be adjusted, greatly reducing the disturbance to the cement kiln tail system 2.
[0042] The system 1 for coupling gangue calcination and cement production provided by the embodiment of the utility model, when calcining normal temperature gangue, a part of the hot air separated from the tertiary air duct 23 of the cement kiln tail system 2 is used as a heat source to raise the temperature of the heated gangue powder and the heated air in the suspended calcining furnace 11 to 850℃~950℃, and the heated gangue powder is ignited and suspended and heated and burned, and then the amount of hot air introduced is gradually reduced to obtain a high-temperature mixture, wherein the blast air volume is adapted to the pressure of the cement kiln tail system 2. Within this temperature range, the heated gangue powder entering the suspended calcining furnace 11 undergoes clay mineral decomposition reaction and coal combustion reaction. Generally, the calorific value of gangue is in the range of 600Cal / kg~1000Cal / kg (2509J / kg~4182J / kg), and the heat release of coal combustion can supplement the heat absorption of clay mineral decomposition to a certain extent, while realizing energy utilization and reducing process energy consumption. Then the high temperature mixture is separated to obtain high temperature calcined coal gangue and high temperature calcined flue gas. Then the room temperature air is heated by the high temperature calcined coal gangue at 800℃~900℃ to obtain the heated air at 500℃~600℃ which is input into the suspended calcining furnace 11, and the high temperature calcined coal gangue is cooled to 120℃~150℃ to obtain the low temperature calcined coal gangue which is discharged.
[0043] As the temperature of the normal temperature air gradually increases, the amount of hot air separated by the tertiary air duct 23 gradually decreases, and finally the heat in the suspended state calciner 11 is close to a self-balanced state. In this state, the tertiary air duct 23 only needs a small amount of hot air to keep the temperature of the suspended state calciner 11 stable, which is not only conducive to the full decomposition of clay minerals and the full removal of carbon in the heated coal gangue powder, but also the high-temperature calcined flue gas heats the normal temperature coal gangue powder in the preheating mechanism 13 to obtain 500℃~600℃ heated coal gangue powder, and cools itself to obtain 600℃~700℃ cooled calcined flue gas, which can fully utilize the energy of the high-temperature calcined flue gas. The cooled calcined flue gas is input into the cement kiln tail system 2, and the cement raw material is gradually heated, and it is gradually cooled in the cement kiln tail system 2 and discharged after being purified, thereby compensating to a certain extent the energy loss of the cement kiln tail system 2 caused by the shunt hot air of the tertiary air duct 23.
[0044] When combining the calcined gangue system with the cement production system, it is necessary to fully consider the matching of the process flow and the feasibility of the transformation implementation, and try to minimize or avoid the impact on the main process of the cement production process, especially the impact of the introduction of the new system on the thermal state of the cement production system. In the embodiment of the utility model, the resistance drop from the bottom of the suspended calcining furnace 11 to the air flow inlet of the suspended preheater 21 where the gas outlet of the preheating mechanism 13 is equal to the pressure is about 2200Pa ~ 3000Pa, that is, the negative pressure from this system to the connection with the cement kiln tail system 2 is about -3000Pa ~ -2200Pa. Since the wind pressure is equivalent to the negative pressure of the air flow inlet of the suspended preheater 21 where the gas outlet of the preheating mechanism 13 is equal to the pressure, and the temperature is also close, after the hot air of this system is introduced into the cement kiln tail system 2, it will not cause significant disturbance to the thermal state of the cement kiln tail system 2.
[0045] Calcining coal gangue will produce a certain amount of pollutants, such as volatiles, CO, CO2 and SO2 produced by pyrolysis or combustion. If the process flow is not properly set, these pollutants will cause the cement tail gas purification mechanism 22 to be overloaded, resulting in excessive emission indicators. In the embodiment of the utility model, the high-temperature calcination flue gas such as volatiles, CO, CO2 and SO2 produced by coal pyrolysis or combustion in the heated coal gangue powder is separated by the separator 12, cooled by the preheating mechanism 13, and purified by the multi-stage suspension preheater 21 of the cement kiln tail system 2, which significantly prolongs the residence time of the pollutants. The volatiles and CO therein have enough time to be fully and gradually burned and completely converted into CO2 and water vapor. SO2 contacts the cement raw material in the multi-stage suspension preheater 21, is adsorbed by the CaO particles in the cement raw material, solidified and collected, thereby reducing emissions and reducing pollution. As a result, the cooling calcination flue gas can directly use the tail gas purification mechanism 22 of the cement production system, and will not cause abnormal emission indicators of the tail gas purification mechanism 22. From the perspective of reducing pollutant emissions and reducing environmental protection investment, it is also appropriate to preheat the room temperature coal gangue powder with the high-temperature calcination flue gas generated by the suspended calcining furnace 11 to obtain cooled calcination flue gas, and then introduce the cooled calcination flue gas into the suspension preheater 21 of the cement kiln tail system 2.
[0046] Combining calcined gangue with cement production technology is a reasonable process technology development trend, which can not only achieve material coupling, but also achieve the purpose of efficient energy utilization. On the one hand, calcined gangue can be directly used in cement production, which not only comprehensively utilizes waste gangue but also reduces cement clinker consumption, playing a role in cement energy saving and carbon reduction. Using calcined gangue to produce low-carbon cementitious materials can reduce energy consumption by 10% to 30% and reduce CO2 emissions by 20% to 40% per ton of product. On the other hand, the cooling calcined flue gas can also be used in cement technology (such as raw material preheating, waste heat power generation, etc.), realize energy recovery and help reduce fuel consumption in cement production. Therefore, the formation of a joint process system of calcined gangue and cement production has coupling advantages in terms of material and energy utilization, which is in line with the current industrial development trend of solid waste utilization, energy saving and carbon reduction.
[0047] In summary, the system 1 for coupling gangue calcination and cement production provided by the embodiment of the utility model can ignite the gangue in the suspended calcining furnace 11 through a part of the hot air and heated air separated by the tertiary air duct 23, and maintain the combustion of the gangue powder. After the gangue is burned, the energy released by itself is used to heat the normal temperature gangue powder in the preheating mechanism 13, and is used to heat the normal temperature air in the cooling mechanism 14, and the heat energy of the cement kiln tail system 2 is supplemented by the cooling calcination flue gas, which effectively solves the energy utilization, reduces the disturbance during cement production, and can use the cement kiln tail system 2 to dispose of gaseous pollutants and reduce pollutant emissions. The method has a simple process and a small structural footprint, which is convenient to implement in the form of an additional module on the suspended preheater 21 of the cement kiln tail system 2, and does not require additional tail gas purification equipment investment. The matching problem of the two process flows is fully considered, the impact on the existing cement process is small, the energy utilization efficiency is high, and the self-balancing state can be achieved, no additional energy consumption is required, and it is very energy-saving. The calcined gangue product of the utility model can replace 30% to 40% of cement clinker, and the production process has low energy consumption and low carbon emission, and the goal of energy saving and carbon reduction in cement production is achieved while realizing the comprehensive utilization of gangue.
[0048] Furthermore, the preheating mechanism 13 includes a multi-stage preheater 131. The preheater 131 may be a cyclone.
[0049] Normal temperature coal gangue powder is input from the air inlet pipe of the first-stage preheater 131, so that the gas flowing through the air inlet pipe of the first-stage preheater P1 can preheat the normal temperature coal gangue powder once, the discharge port of the upper-stage preheater 131 is connected with the air inlet pipe of the lower-stage preheater 131, so that the gas flowing through the air inlet pipe of the lower-stage preheater 131 can preheat the heated coal gangue powder again, and the discharge port of the final-stage preheater 131 is connected with the bottom of the suspended calcining furnace 11. The above-mentioned multi-stage preheating of normal temperature coal gangue powder by high-temperature calcination flue gas obtains heated coal gangue powder.
[0050] The gas outlet of the separator 12 is connected with the gas inlet of the final preheater 131, so that the N-1 times heated gangue output from the discharge port of the next final preheater 131 can be heated N times, the gas outlet of the next stage preheater 131 is connected with the gas inlet of the previous stage preheater 131, so that the heated gangue output from the discharge port of the next stage preheater 131 can be heated again, the gas outlet of the first stage preheater 131 is connected with the gas inlet of the suspended preheater 21 of the cement kiln tail system 2 which is isobaric with the gas outlet of the preheating mechanism 13, so that the high-temperature calcination flue gas is cooled step by step in multiple stages to obtain cooled calcination flue gas, the cooled calcination flue gas heats the cement raw material step by step in multiple stages, cools itself step by step in multiple stages and is discharged after being purified.
[0051] The multi-stage preheater 131 is provided, so that the heat energy of the high-temperature calcined flue gas can be fully utilized in multiple stages to heat the normal-temperature coal gangue powder to obtain the heated coal gangue powder, so that the heat energy of the calcined coal gangue can be fully utilized, so that the heated coal gangue powder entering the suspended calcining furnace 11 for combustion has a certain temperature, which is convenient for ignition. The normal-temperature coal gangue powder is input from the air inlet pipe of the first-stage preheater 131, and the discharge port of the upper-stage preheater 131 is connected with the air inlet pipe of the lower-stage preheater 131. In this way, the high-temperature calcined coal gangue separated from the separator 12 heats the N-1 heated coal gangue, and the heat utilization rate is higher. If the normal temperature coal gangue powder is input from the air inlet pipe of the final stage preheater 131 and finally output from the first stage preheater 131, in this process, the high temperature calcination flue gas with the highest temperature heats the normal temperature coal gangue powder, and then the high temperature calcination flue gas gradually cools down, and the temperature of the heated normal temperature coal gangue powder also gradually decreases, and the heat utilization rate of the whole process is low.
[0052] Optionally, the preheating mechanism 13 includes a two-stage preheater 131. Figure 1 As shown, the room temperature coal gangue powder is input from the air inlet pipe of the first stage preheater P1 (first stage preheater 131), the discharge port of the first stage preheater P1 is connected with the air inlet pipe of the second stage preheater P2, and the discharge port of the second stage preheater P2 (final stage preheater 131) is connected with the bottom of the suspension calcining furnace 11. The gas outlet of the separator 12 is connected with the gas input port of the second stage preheater P2 (final stage preheater 131), the gas outlet of the second stage preheater P2 is connected with the gas input port of the first stage preheater P1, and the gas outlet of the first stage preheater P1 (first stage preheater 131) is connected with the gas inlet of the suspension preheater 21 of the cement kiln tail system 2 where the gas outlet of the preheating mechanism 13 is isobaric. Specifically, as Figure 1As shown, in practice, the commonly used cement kiln tail system 2 is a double series cyclone mechanism, each group of cyclone mechanisms includes a five-stage suspension preheater 21, and the air flow inlet of the third-stage suspension preheater 21 is the air flow inlet of the suspension preheater 21 at the same pressure as the gas output port of the preheating mechanism 13. The cooling calcination flue gas output by the first-stage preheater P1 is divided into two paths, which are respectively connected to the air flow inlets of the third-stage suspension preheaters C3A and C3B in the cement kiln tail system 2.
[0053] If a first-stage preheater 131 is set, the temperature of the output cooling calcined flue gas is relatively high, and the temperature of the heated coal gangue powder is relatively low, and the required temperature cannot be reached. If a preheater 131 of more than three stages is set, the temperature of the output cooling calcined flue gas is relatively low, and the number of stages connected to the cement kiln tail system 2 is relatively low, and the pressures of the two systems are not easily mismatched. If the preheating mechanism 13 is set as a two-stage preheater 131, the pressure and temperature of the output cooling calcined flue gas are matched and balanced with the pressure and temperature of the cement kiln tail system 2, and cost can also be saved.
[0054] Furthermore, the cooling mechanism 14 includes a multi-stage cooler 141 .
[0055] The discharge port of the separator 12 is connected to the air inlet pipe of the first-stage cooler 141, and the high-temperature calcined coal gangue is input from the air inlet pipe of the first-stage cooler 141, so that the high-temperature calcined coal gangue output from the discharge port of the separator 12 can be cooled once to obtain once-cooled calcined coal gangue, and the N-1 heated air is heated N times to obtain heated air, and the discharge port of the upper-stage cooler 141 is connected to the air inlet pipe of the lower-stage cooler 141, so that the cooled calcined coal gangue output from the discharge port of the upper-stage cooler 141 can be cooled again, and the heated air is heated again, and the discharge port of the final-stage cooler 141 outputs low-temperature calcined coal gangue, so that the high-temperature calcined coal gangue is cooled step by step by normal temperature gas to obtain low-temperature calcined coal gangue, and it itself is heated step by step by multiple stages to obtain heated air.
[0056] Normal temperature air is input from the air inlet pipe of the final stage cooler 141 , the gas outlet of the next stage cooler 141 is connected to the gas inlet of the previous stage cooler 141 , and the gas outlet of the first stage cooler 141 is connected to the gas inlet of the blowing mechanism 15 .
[0057] The multi-stage cooler 141 is provided to fully utilize the heat energy of the high-temperature calcined coal gangue to heat the room-temperature air to obtain heated air, so that the heat energy of the high-temperature calcined coal gangue can be fully utilized, so that the heated gas entering the suspended calcining furnace 11 for combustion has a certain temperature, which is convenient for ignition of the heated coal gangue powder and has a higher heat utilization rate.
[0058] Optionally, the cooling mechanism 14 includes a three-stage cooler 141. Figure 1As shown, the discharge port of the separator 12 is connected to the air inlet pipe of the first-stage cooler CL1 (first-stage cooler 141), so that the high-temperature calcined coal gangue output from the discharge port of the separator 12 can be cooled once to obtain the first-cooled calcined coal gangue, and the secondary heated air can be heated three times to obtain the warmed air. The discharge port of the first-stage cooler CL1 is connected to the air inlet pipe of the second-stage cooler CL2, so that the first-cooled calcined coal gangue output from the discharge port of the first-stage cooler 141 can be cooled twice to obtain the second-cooled calcined coal gangue, and the primary heated air can be heated twice to obtain the secondary heated air. The discharge port of the second-stage cooler CL2 is connected with the air inlet pipe of the third-stage cooler CL3, so that the secondary cooled calcined coal gangue outputted from the discharge port of the second-stage cooler 141 can be cooled thrice to obtain low-temperature calcined coal gangue, and the normal temperature air is heated once to obtain primary heated air. The discharge port of the third-stage cooler CL3 (final-stage cooler 141) outputs low-temperature calcined coal gangue, which is an activated product. Thus, the high-temperature calcined coal gangue is cooled step by step by normal temperature air to obtain low-temperature calcined coal gangue, which is heated step by step by multiple stages to obtain heated air and input into the suspension calcining furnace for calcination.
[0059] Normal temperature air is input from the air inlet pipe of the third stage cooler CL3 (final stage cooler 141), the gas outlet of the third stage cooler CL3 is connected with the gas outlet of the second stage cooler CL2, the gas outlet of the second stage cooler 141 is connected with the gas outlet of the first stage cooler CL1, and the gas outlet of the first stage cooler CL1 is connected with the gas outlet of the blowing mechanism 15.
[0060] If the cooler 141 is greater than the third level, the wind resistance will increase, and the blowing capacity of the blowing mechanism 15 needs to be enhanced, and the energy consumption and cost are high. If the cooler 141 is less than the third level, the heat energy of the high-temperature calcined coal gangue cannot be fully utilized to heat the normal temperature air, and the temperature of the low-temperature calcined coal gangue obtained is high. Setting the cooler 141 to the third level can better utilize the heat energy of the high-temperature calcined coal gangue, the wind resistance is appropriate, and the cost can be saved at the same time.
[0061] The overall gas flow direction of the embodiment of the present application is as follows: normal temperature air enters the cooling mechanism 14 from the gas input port of the third-stage cooler CL3, passes through the third-stage cooler CL3, the second-stage cooler CL2 and the first-stage cooler CL1 in sequence, and becomes heated air after three heat exchanges with high-temperature calcined coal gangue. After being pumped and blown by the blowing mechanism 15, it enters the suspended calcining furnace 11 together with the hot air from the tertiary air duct 23. Subsequently, after passing through the suspended calcining furnace 11, the separator 12, the second-stage preheater P2, and the first-stage preheater P1 in sequence, it is divided into two paths and enters the third-stage suspended preheaters C3A and C3B of the cement kiln tail system 2 respectively. Finally, it is purified by the tail gas purification system of the cement kiln tail system 2 and discharged.
[0062] The overall material flow of the embodiment of the present application is as follows: room temperature coal gangue powder is input from the air inlet pipe of the first stage preheater P1, and is discharged from the discharge pipe into the second stage preheater P2 after being preheated by the first stage preheater P1. After being preheated by the second stage preheater P2, it enters the suspended calcining furnace 11 through the discharge pipe. After completing the reaction in the suspended calcining furnace 11, it enters the separator 12. After being separated by the cyclone separator 12, it is discharged from the solid output port and then enters the cooling mechanism 14. In the cooling mechanism 14, after passing through the first stage cooler CL1, the second stage cooler CL2 and the third stage cooler CL3 in sequence, it is discharged from the discharge pipe of the third stage cooler CL3 to obtain low-temperature calcined coal gangue, which is an activated product.
[0063] To further illustrate the present invention, a specific embodiment is given here.
[0064] A system 1 for coupling gangue calcination and cement production, the specific process is as follows:
[0065] The output port of the tertiary air duct 23 of the cement kiln tail system 2 and the output port of the blowing mechanism 15 are both connected to the input port of the suspended calcining furnace 11, so that a part of the hot air separated by the tertiary air duct 23 and the heated air after being blown by the blowing mechanism 15 can ignite and suspend the heated coal gangue powder, and then gradually reduce the amount of hot air introduced to obtain a high-temperature mixture, wherein the blowing air volume is adapted to the pressure of the cement kiln tail system 2.
[0066] The output port of the suspended calcining furnace 11 is connected to the input port of the cyclone separator 12, and the cyclone separator 12 is configured to separate the high-temperature mixture into high-temperature calcined coal gangue and high-temperature calcined flue gas. The gas output port of the cyclone separator 12 is connected to the gas input port of the second-stage preheater P2 of the preheating mechanism 13. The gas output port of the second-stage preheater P2 is connected to the gas input port of the first-stage preheater P1 of the preheating mechanism 13. The cooled calcined flue gas output from the gas output port of the first-stage preheater P1 is divided into two paths, which are respectively connected to the air flow inlets of the third-stage cyclones C3A and C3B in the cement kiln tail system 2. The cooling mechanism 14 is composed of a three-stage cooler 141. The gas input port of the third-stage cooler CL3 is connected to the atmospheric environment, and inputs normal temperature air. The gas output port of the third-stage cooler CL3 is connected to the gas input port of the second-stage cooler CL2, and the gas output port of the second-stage cooler CL2 is connected to the gas input port of the first-stage cooler CL1, and the gas output port of the first-stage cooler CL1 is connected to a high-temperature fan. The outlet of the high-temperature fan is connected to the lower air inlet of the suspended calcining furnace 11. The feed pipe of the first-stage preheater P1 is connected to the air inlet pipe of the second-stage preheater P2. The feed pipe of the second-stage preheater P2 is connected to the feed port at the bottom of the suspended calcining furnace 11. The feed pipe of the cyclone separator 12 is connected to the air inlet pipe of the first cooler CL1 of the cooling mechanism 14. The feed pipe of the first cooler CL1 is connected to the air inlet pipe of the second cooler CL2. The feed pipe of the second cooler CL2 is connected to the air inlet pipe of the third cooler CL3. The high-temperature calcined coal gangue is discharged from the discharge pipe of the third cooler CL3 to obtain low-temperature calcined coal gangue, that is, the activated product.
[0067] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other. Each embodiment focuses on the differences from other embodiments.
[0068] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit the present application. Although the present application has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some or all of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present application.
Claims
1. A system for coupling gangue calcination and cement production, characterized in that: It includes a suspension calcining furnace, a separator, a preheating mechanism, a cooling mechanism and a blast mechanism; The output port of the tertiary air duct of the cement kiln tail system and the output port of the blast mechanism are both connected to the input port of the suspension calciner, so that a part of the hot air separated by the tertiary air duct and the heated air after being blown by the blast mechanism ignite the heated coal gangue powder in the suspension calciner and suspend and heat it, and then gradually reduce the amount of the hot air introduced to obtain a high-temperature mixture, wherein the blast air volume is adapted to the pressure of the cement kiln tail system; The output port of the suspension calcining furnace is connected to the input port of the separator, and the separator is configured to separate the high-temperature mixture into high-temperature calcined coal gangue and high-temperature calcined flue gas; The gas output port of the separator is connected to the gas input port of the preheating mechanism so as to input the separated high-temperature calcination flue gas into the gas input port of the preheating mechanism; The gas outlet of the preheating mechanism is connected to the gas inlet of the suspension preheater of the cement kiln tail system which is at the same pressure as the gas outlet of the preheating mechanism; The air inlet pipe of the preheating mechanism inputs room temperature coal gangue powder and is heated by the high temperature calcination flue gas to obtain heated coal gangue powder and cooled calcination flue gas, the cooled calcination flue gas gradually heats the cement raw material, gradually cools itself and is discharged after being purified; The solid output port of the separator is communicated with the air inlet pipe of the cooling mechanism to input the separated high-temperature calcined coal gangue into the air inlet pipe of the cooling mechanism; Normal temperature air is input into the gas input port of the cooling mechanism and is heated by the high temperature calcined coal gangue to obtain the heated air, and the high temperature calcined coal gangue is cooled to obtain low temperature calcined coal gangue; The gas outlet of the cooling mechanism is communicated with the gas inlet of the blowing mechanism, and the heated air is blown by the blowing mechanism and then input into the suspension calcining furnace.
2. The system for coupling gangue calcination and cement production according to claim 1, characterized in that: The preheating mechanism includes a multi-stage preheater; The room temperature coal gangue powder is input from the air inlet pipe of the first stage preheater, the discharge port of the upper stage preheater is connected with the air inlet pipe of the lower stage preheater, and the discharge port of the last stage preheater is connected with the bottom of the suspended calcining furnace; The gas outlet of the separator is connected to the gas inlet of the last-stage preheater, the gas outlet of the next-stage preheater is connected to the gas inlet of the previous-stage preheater, and the gas outlet of the first-stage preheater is connected to the air flow inlet of the suspended preheater of the cement kiln tail system which is isobaric with the gas outlet of the preheating mechanism.
3. The system for coupling gangue calcination and cement production according to claim 2, characterized in that: The preheating mechanism includes two stages of preheaters.
4. The system for coupling gangue calcination and cement production according to claim 1, characterized in that: The cooling mechanism includes a multi-stage cooler; The discharge port of the separator is connected to the air inlet pipe of the first-stage cooler, the high-temperature calcined coal gangue is input from the air inlet pipe of the first-stage cooler, the discharge port of the upper-stage cooler is connected to the air inlet pipe of the lower-stage cooler, and the discharge port of the last-stage cooler outputs the low-temperature calcined coal gangue; Normal temperature air is input from the air inlet pipe of the last stage cooler, the gas outlet of the next stage cooler is connected with the gas inlet of the previous stage cooler, and the gas outlet of the first stage cooler is connected with the gas inlet of the blowing mechanism.
5. The system for coupling gangue calcination and cement production according to claim 4, characterized in that: The cooling mechanism includes three stages of coolers.