Novel self-denitration carbide slag cement kiln production line
By sending the high-temperature exhaust gas from the C2 preheater to the drying crusher in the carbide slag cement kiln production line and injecting ammonia water under high-temperature conditions, the problems of low denitrification efficiency and ammonia escape were solved, achieving a denitrification effect with ultra-low emissions.
Patent Information
- Application Number
- CN202422368670.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-27
- Publication Date
- 2025-11-07
- Estimated Expiration
- 2034-09-27
AI Technical Summary
Existing carbide slag cement kiln production lines suffer from low denitrification efficiency and severe ammonia escape, failing to meet ultra-low emission standards. Furthermore, current technologies cannot effectively address the adaptability of SCR catalysts under high-temperature conditions and the uniform distribution of ammonia water under low-temperature conditions.
By directly sending the high-temperature exhaust gas from the C2 preheater to the drying crusher, the temperature of the drying crusher is increased, and ammonia water is injected at this point. Combined with the three-stage preheater structure, this ensures the full reaction of ammonia and nitrogen oxides and reduces ammonia escape.
It achieves an effective reaction between ammonia and nitrogen oxides under low-temperature conditions, improves denitrification efficiency, meets ultra-low emission standards, and reduces ammonia escape, thereby lowering treatment costs and flue gas pollution.
Smart Images
Figure CN223525590U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of cement kiln denitrification technology, and in particular to a novel self-denitrifying calcium carbide slag cement kiln production line. Background Technology
[0002] Cement kilns are rotary kilns used for calcining cement clinker. Existing cement kiln production lines primarily employ staged combustion combined with SNCR or SCR to achieve ultra-low emissions. Figure 1 As shown, however, such production lines generally have insufficient tailings coal consumption, resulting in poor denitrification effect of staged combustion in cement kilns, failing to meet the requirement of NOx < 50 mg / Nm³. 3 The emission standards are inadequate. Even if some production lines have sufficient tailings coal, the scaling problem commonly found in calcium carbide slag production lines is exacerbated by staged combustion, which further affects clinker yield and quality. Furthermore, the outlet temperature of the C1 preheater in calcium carbide slag production lines is generally between 400 and 700℃, which is unsuitable for SCR catalyst operation. Additionally, the outlet temperatures of the drying crusher and the end-of-line dust collector in calcium carbide slag cement kilns are generally set relatively low based on energy consumption and the amount of material being dried; currently, there are no suitable low-temperature catalysts on the market. In other words, existing calcium carbide slag cement kiln clinker production lines, except for simple SNCR denitrification, do not meet the environmental protection requirement of NOx < 50 mg / Nm³. 3 While SNCR is a feasible method, it involves directly injecting ammonia water into the flue gas. At a suitable temperature, ammonia comes into contact with nitrogen oxides in the flue gas to achieve denitrification. However, the ammonia water is not evenly distributed in the flue gas, resulting in relatively low denitrification efficiency and failing to meet the ultra-low emission standards. When the flue gas temperature decreases, the reaction regulation between ammonia and nitrogen oxides cannot be achieved, leading to unsatisfactory SNCR denitrification efficiency and causing ammonia escape.
[0003] The treatment of nitrogen oxides in calcium carbide slag cement kiln production lines not only faces technical bottlenecks, but also suffers from high ammonia content due to the high ammonia content in calcium carbide slag. During drying and crushing, gaseous ammonia mixes with the waste gas, resulting in extremely high ammonia slip (200–400 mg / Nm³) in calcium carbide slag production lines. 3 The concentration of NH3 is far higher than the environmental protection requirement of ≤5 mg / Nm³. 3 Currently, there is no mature solution for ammonia escape besides flue gas acid washing, which is not only expensive but also produces yellow smoke after treatment.
[0004] In conclusion, the problems of denitrification and ammonia escape in carbide slag production lines urgently need to be addressed. Utility Model Content
[0005] The utility model discloses a purpose at solving the problem in the background art provides a novel carbide slag cement kiln production line of self denitration, and novel production line can solve the problem of denitration and ammonia escape.
[0006] The utility model discloses a purpose is realized through the following technical schemes:
[0007] A novel carbide slag cement kiln production line of self denitration, including rotary kiln, smoke chamber, decomposing furnace, C1 preheater, C2 preheater, C3 preheater, raw material conveying system, carbide slag conveying system, drying crusher and cyclone dust collector, the tail of rotary kiln is connected with smoke chamber, and the decomposing furnace is located the top of smoke chamber, C1 preheater, C2 preheater and C3 preheater are sequentially arranged from top to bottom above smoke chamber, the discharge pipe of raw material conveying system is connected with the air inlet pipe of C1 preheater, the discharge pipe of C1 preheater is connected with the air inlet pipe of C2 preheater, the discharge pipe of C2 preheater is connected with the lower part of decomposing furnace, the exhaust pipe of decomposing furnace top is connected with the air inlet pipe of C3 preheater, the discharge pipe of C3 preheater is connected with the communication of smoke chamber and rotary kiln, the exhaust pipe of C3 preheater is connected with the discharge pipe of C1 preheater, the exhaust pipe of C2 preheater is connected with the inlet end of drying crusher, the carbide slag conveying system is connected with the exhaust pipe of C2 preheater, the outlet end of drying crusher is connected with the air inlet of cyclone dust collector, the discharge end of cyclone dust collector is connected with dry carbide slag warehouse, the exhaust pipe of cyclone dust collector is connected with the discharge pipe of raw material conveying system, and the exhaust pipe of cyclone dust collector is connected with the air inlet pipe of C1 preheater, and the exhaust pipe of C1 preheater is connected with high temperature fan.
[0008] In addition, the inlet end of the drying crusher can be connected with the exhaust pipe of the C3 preheater, thereby providing a higher working temperature for the drying crusher.
[0009] The novel carbide slag cement kiln production line of self denitration has the beneficial effects that: by connecting the exhaust pipe of the C2 preheater with the drying crusher, compared with the traditional carbide slag cement kiln production line, the gas temperature entering the inlet of the drying crusher is improved, thereby improving the initial temperature of the reaction between ammonia and nitrogen oxides in the carbide slag, and ensuring the automatic denitration effect of the production line system. BRIEF DESCRIPTION OF DRAWINGS
[0010] In order to more clearly illustrate the technical scheme of the embodiments of the utility model, the following will be needed to use the drawings in the embodiment briefly introduces, should understand, the following drawings only shows some embodiments of the utility model, therefore should not be regarded as the limitation to the range, for the ordinary skilled person in the art comes, under the premise of not paying the creative labor, can also obtain other related drawings according to these drawings.
[0011] Figure 1 It is the structural schematic diagram of the existing carbide slag cement kiln production line.
[0012] Figure 2 The utility model discloses a novel structure diagram of the production line of the cement kiln of carbide slag.
[0013] The figure shows that, the utility model discloses a novel structure diagram of the production line of the cement kiln of carbide slag, and the broken line in the drawing indicates the flow direction of tail gas, and the realization in the drawing indicates the flow direction of material, the novel cement kiln of carbide slag of self denitration provided by the embodiment of the utility model, including rotary kiln 1, smoke chamber 2, decomposing furnace 3, C1 preheater 4, C2 preheater 5, C3 preheater 6, raw material conveying system 7, carbide slag conveying system 8, drying crusher 9 and cyclone dust collector 10, the tail of rotary kiln 1 is communicated with smoke chamber 2, and decomposing furnace 3 is located at the top of smoke chamber 2, C1 preheater 4, C2 preheater 5 and C3 preheater 6 are sequentially arranged from top to bottom above smoke chamber 2, the discharge pipe of raw material conveying system 7 is communicated with the air inlet pipe of C1 preheater 4, and the discharge end of raw material conveying system 7 is introduced into C1 preheater 4, to improve the temperature of tail gas flowing to drying crusher 9, the discharge pipe of C1 preheater 4 is connected with the air inlet pipe of C2 preheater 5, the discharge pipe of C2 preheater 5 is communicated with the lower part of decomposing furnace 3, the exhaust pipe at the top of decomposing furnace 3 is communicated with the air inlet pipe of C3 preheater 6, the discharge pipe of C3 preheater 6 is communicated with smoke chamber 2 and rotary kiln 1, the exhaust pipe of C3 preheater 6 is connected with the discharge pipe of C1 preheater 4, the exhaust pipe of C2 preheater 5 is communicated with the inlet end of drying crusher 9, the carbide slag conveying system 8 is communicated with the exhaust pipe of C2 preheater 5, the outlet end of drying crusher 9 is communicated with the air inlet of cyclone dust collector 10, the high-temperature waste gas at the outlet of C2 preheater 5 is directly flowed to drying crusher 9 instead of flowing through C1 preheater 4 for cooling as the traditional waste gas flow direction, so that the reaction between ammonia and nitrogen oxide can be strengthened due to the temperature rise of ammonia generated when drying crusher 9 crushes carbide slag, thereby improving the denitration effect of the cement kiln, and the escape of ammonia is reduced, the discharge end of cyclone dust collector 10 is connected with dry carbide slag warehouse 11, the exhaust pipe of cyclone dust collector 10 is communicated with the discharge pipe of raw material conveying system 7, and the exhaust pipe of cyclone dust collector 10 is connected with the air inlet pipe of C1 preheater 4, and the exhaust pipe of C1 preheater 4 is connected with high-temperature fan 12. DETAILED DESCRIPTION
[0014] Embodiment 1
[0015] As Figure 2 shown, Figure 2 The utility model discloses a novel structure diagram of the production line of the cement kiln of carbide slag, and the broken line in the drawing indicates the flow direction of tail gas, and the realization in the drawing indicates the flow direction of material, the novel cement kiln of carbide slag of self denitration provided by the embodiment of the utility model, including rotary kiln 1, smoke chamber 2, decomposing furnace 3, C1 preheater 4, C2 preheater 5, C3 preheater 6, raw material conveying system 7, carbide slag conveying system 8, drying crusher 9 and cyclone dust collector 10, the tail of rotary kiln 1 is communicated with smoke chamber 2, and decomposing furnace 3 is located at the top of smoke chamber 2, C1 preheater 4, C2 preheater 5 and C3 preheater 6 are sequentially arranged from top to bottom above smoke chamber 2, the discharge pipe of raw material conveying system 7 is communicated with the air inlet pipe of C1 preheater 4, and the discharge end of raw material conveying system 7 is introduced into C1 preheater 4, to improve the temperature of tail gas flowing to drying crusher 9, the discharge pipe of C1 preheater 4 is connected with the air inlet pipe of C2 preheater 5, the discharge pipe of C2 preheater 5 is communicated with the lower part of decomposing furnace 3, the exhaust pipe at the top of decomposing furnace 3 is communicated with the air inlet pipe of C3 preheater 6, the discharge pipe of C3 preheater 6 is communicated with smoke chamber 2 and rotary kiln 1, the exhaust pipe of C3 preheater 6 is connected with the discharge pipe of C1 preheater 4, the exhaust pipe of C2 preheater 5 is communicated with the inlet end of drying crusher 9, the carbide slag conveying system 8 is communicated with the exhaust pipe of C2 preheater 5, the outlet end of drying crusher 9 is communicated with the air inlet of cyclone dust collector 10, the high-temperature waste gas at the outlet of C2 preheater 5 is directly flowed to drying crusher 9 instead of flowing through C1 preheater 4 for cooling as the traditional waste gas flow direction, so that the reaction between ammonia and nitrogen oxide can be strengthened due to the temperature rise of ammonia generated when drying crusher 9 crushes carbide slag, thereby improving the denitration effect of the cement kiln, and the escape of ammonia is reduced, the discharge end of cyclone dust collector 10 is connected with dry carbide slag warehouse 11, the exhaust pipe of cyclone dust collector 10 is communicated with the discharge pipe of raw material conveying system 7, and the exhaust pipe of cyclone dust collector 10 is connected with the air inlet pipe of C1 preheater 4, and the exhaust pipe of C1 preheater 4 is connected with high-temperature fan 12.
[0016] Embodiment 2
[0017] The embodiment is basically same as the embodiment 1, since the temperature of the C3 preheater, the C2 preheater and the C1 preheater is gradually reduced, in order to adapt to different drying temperature, the inlet end of the drying crusher 9 can also be communicated with the exhaust pipe of the C3 preheater 6, at this time, the exhaust pipe of the cyclone dust collector 10 is communicated with the air inlet pipe of the C2 preheater 5.
[0018] The use method of the utility model is:
[0019] By directly sending the high-temperature tail gas of the C2 preheater 5 to the drying crusher 9, the drying temperature of the drying crusher 9 is improved, so that the carbide slag is crushed by the drying crusher 9, under the premise of ensuring the flue gas temperature, the ammonia water sprayed into the flue gas in front of the denitration process can fully contact the nitrogen oxides in the flue gas. At the same time, the drying crusher 9 of the carbide slag is a place where material and flue gas concentrate heat exchange, its structure not only makes the material and the waste gas fully contact, but also makes the ammonia and nitrogen oxides molecules in the waste gas fully mix; in addition, the drying crusher 9 is not only a place where ammonia is overflowed from the carbide slag, but also a place where the SNCR ammonia escape in front of the flue gas will pass through, that is, whether the front-end ammonia escape or the ammonia of the carbide slag material will fully contact the nitrogen oxides in the waste gas, and cooperate with the high temperature in the tail gas of the C2 preheater 5, so that the reaction temperature condition of NH3 and NO x can be reached, not only the nitrogen oxides treatment problem can be solved, but also the ammonia escape problem can be solved.
[0020] After the cyclone dust collector 10 separates the carbide slag crushed by the drying crusher 9, the preheating tail gas flows back to the C1 preheater 4 for waste heat recovery, the cement kiln production line adopting the structure only needs to make small changes to the position of the original production line, so that the production line can meet the automatic denitration function.
[0021] The above is only the preferred three-stage preheater of the utility model, the improved structure embodiment can also be adopted in four-stage or five-stage preheater, the protection scope of the utility model is not limited to this, any modification and replacement based on the technical scheme and the utility model concept provided by the utility model should be covered in the protection scope of the utility model. It should be noted that the structures or components illustrated in the drawings are not necessarily drawn to scale, and the utility model omits the description of the known components and processing technology and process, so as to avoid unnecessary limitation of the utility model.
Claims
1. A novel self-denitration carbide slag cement kiln production line, comprising a rotary kiln (1), a flue chamber (2), a decomposing furnace (3), a C1 preheater (4), a C2 preheater (5), a C3 preheater (6), a raw material conveying system (7), a carbide slag conveying system (8), a drying crusher (9) and a cyclone dust collector (10), the tail of the rotary kiln (1) is communicated with the flue chamber (2), the decomposing furnace (3) is located at the top of the flue chamber (2), and the C1 preheater (4), the C2 preheater (5) and the C3 preheater (6) are sequentially arranged from top to bottom above the flue chamber (2), characterized in that: The discharge pipe of the raw material conveying system (7) is communicated with the air inlet pipe of the C1 preheater (4), the discharge pipe of the C1 preheater (4) is connected with the air inlet pipe of the C2 preheater (5), the discharge pipe of the C2 preheater (5) is communicated with the lower part of the decomposition furnace (3), the exhaust pipe of the top of the decomposition furnace (3) is communicated with the air inlet pipe of the C3 preheater (6), the discharge pipe of the C3 preheater (6) is connected with the flue chamber (2) and the rotary kiln (1), the exhaust pipe of the C3 preheater (6) is connected with the discharge pipe of the C1 preheater (4), the exhaust pipe of the C2 preheater (5) is communicated with the inlet end of the drying crusher (9), the calcium carbide slag conveying system (8) is communicated with the exhaust pipe of the C2 preheater (5), the outlet end of the drying crusher (9) is communicated with the air inlet of the cyclone dust collector (10), the discharge end of the cyclone dust collector (10) is connected with the dry calcium carbide slag warehouse (11), the exhaust pipe of the cyclone dust collector (10) is communicated with the discharge pipe of the raw material conveying system (7), and the exhaust pipe of the cyclone dust collector (10) is connected with the air inlet pipe of the C1 preheater (4), and the exhaust pipe of the C1 preheater (4) is connected with the high-temperature fan (12).
2. A novel self-denitration calcium carbide slag cement kiln production line according to claim 1, characterized by: The inlet end of the drying crusher (9) can be communicated with the exhaust pipe of the C3 preheater (6).