A kind of rotary kiln air distribution technique and system
Technical field
The present invention relates to a kind of air distribution technique and system, especially a kind of rotary kiln air distribution technique and system that is applicable to oxygenized air combustion supporting and flue gas recirculation integrated application in the cement industry.
Background technology
The resource-integrated industry that cement industry is the energy, ore resource consumption is large is subject to the serious restriction of inadequate resource, environmental pollution at present.China's ton cement comprehensive energy consumption is passed away, and also there is a big difference for boundary's level, and coal accounts for 35%-40% in the manufacture of cement cost, and therefore, for cement industry, reducing coal consumption is an effective way that reduces production costs.
Through fast development the Eleventh Five-Year Plan period, China's cement output has reached 18.8 hundred million tons, and wherein new type nonaqueous cement grog production capacity is 12.6 hundred million tons.Annual discharging about 1,900,000 tons of nitrogen oxide (by mean concentration 850mg/Nm3) in the cement production process.Cement output will be broken through 2,000,000,000 tons in this year, and cement industry is the key industry that reduces discharging nitrogen oxide, occupy afterwards the third-largest discharged nitrous oxides industry of thermal power generation, vehicle exhaust.
Present stage, oxygenized air combustion supporting technology or flue gas recirculating technique are used in rotary kiln, can solve subproblem, but have also brought a lot of new troubles simultaneously.It is too fast that the oxygenized air combustion supporting technology exists burning, and the length of flame is short and thick, and heat convection such as weakens at the unfavorable factor in the kiln, and flue gas recirculating technique exists the unfavorable factors such as fuel tolerance is poor.
Summary of the invention
Technical problem: the objective of the invention is to overcome the weak point in the prior art, provide that a kind of technique is simple, capable of reducing energy consumption, generation, the range of choice that improves fuel that reduces nitrogen oxide, rotary kiln air distribution technique and the system that improves system's heat utilization efficiency.
Technical scheme: rotary kiln air distribution technique of the present invention comprises the steps:
A, 90 ℃-350 ℃ flue gas in preheater or the waste heat boiler is drawn, be transported in the deduster through fume pipe, particle, dust in the flue gas are removed, introduce gas recirculating fan through the clean fume pipe of I again;
Flue gas after b, gas recirculating fan will purify is delivered to the flue gas powder feed system through the clean fume pipe of II, delivered in kiln hood burner or the dore furnace by the flue gas powder feed system again, flue gas after maybe will purifying is directly delivered in kiln hood burner or the dore furnace through the clean fume pipe of II, control the exhaust gas volumn that enters in kiln hood burner or the dore furnace by the control valve of regulating on the flue gas pipeline, thereby carry out the shape of flame or the adjusting of position, flame high-temperature region;
C, prepare oxygen enrichment or pure oxygen by oxygen generating plant simultaneously, be transported in the storage tank through I oxygen enrichment pipe by oxygen enrichment or the pure oxygen of oxygen enrichment blower fan with preparation, send into blender and air mixed diluting by II oxygen enrichment pipe again, the oxygen-enriched air that forms 25-40% is transported in kiln hood burner or the dore furnace uses.
Realize the system of above-mentioned rotary kiln air distribution technique, comprise preheater or waste heat boiler, deduster, gas recirculating fan, kiln hood burner or dore furnace, blender, oxygen generating plant, the oxygen enrichment blower fan, storage tank, blower fan, described preheater or waste heat boiler connect deduster through fume pipe, deduster connects gas recirculating fan through the clean fume pipe of I, gas recirculating fan connects the flue gas powder feed system through the clean fume pipe of II, the arrival end that is connected again kiln hood burner or dore furnace by the flue gas powder feed system, or gas recirculating fan directly connects the arrival end of kiln hood burner or dore furnace through the clean fume pipe of II; Described oxygen generating plant connects storage tank through I oxygen enrichment pipe, be connected with the oxygen enrichment blower fan on the pipeline of I oxygen enrichment pipe, storage tank connects the arrival end of blender through II oxygen enrichment pipe, described blower fan is through the arrival end of air hose connection blender, and the port of export of blender connects the arrival end of kiln hood burner or dore furnace through the oxygen-enriched air pipe.
Described flue gas powder feed system comprises the port of export and is connected in powder feeding pipeline and the clean fume pipe of III on kiln hood burner or the dore furnace, the powder feeding pipeline connects the clean fume pipe of IV through the powder feeding blower fan, the arrival end of the clean fume pipe of IV and the clean fume pipe of III links to each other through the clean fume pipe of three-way pipe and II, is provided with successively I control valve, powder feeding blower fan on the powder feeding pipeline and is connected to machine supplying powder under the powder storehouse; The clean fume pipe of III is provided with the V control valve.
Beneficial effect: the present invention fully utilizes at rotary kiln by oxygenized air combustion supporting and flue gas recirculation, reduced the amount of involving in of cold air, reduced coal-fired consumption, regulate flame profile and position, high-temperature region, reduced the generation of nitrogen oxide, improve the range of choice of fuel, improved system's heat utilization efficiency.Flue gas in the coal-fired rotary kiln can pulverized coal conveying, also can regulate the position of flame profile and flame high-temperature region.Use the unfavorable factor that exists for oxygenized air combustion supporting and flue gas recirculation at rotary kiln, with two kinds of effective applied in any combination of technology, can realize following purpose: 1, by oxygenized air combustion supporting, increase the range of choice of fuel, can utilize inferior fuel; 2, utilize flue gas recirculation to regulate the length of flame and position, high-temperature region, strengthen heat convection in the kiln; 3, by the applied in any combination of two kinds of technology, greatly reduce the amount of involving in of cold air, improve system effectiveness, reduce Fuel Consumption, reach energy-conservation purpose; 4, by the applied in any combination of two kinds of technology, reduce nitrogen gas concn, regulate flame profile and control flame temperature, reduce the generation of nitrogen oxide, reach the purpose that reduces discharging nitrogen oxide.Its technique and system are simple, and be easy to operate, and result of use is good, has widely practicality.
Description of drawings
Fig. 1 is coal-fired rotary kiln oxygenized air combustion supporting of the present invention and flue gas recirculation schematic diagram;
Fig. 2 is combustion gas of the present invention or the combustion-supporting and flue gas recirculation schematic diagram of fuel oil rotary kiln oxygen enrichment control.
Among the figure: 1-preheater or waste heat boiler, 2-fume pipe, 3-deduster, the clean fume pipe of 4-I, 5-gas recirculating fan, the clean fume pipe of 6-II, 7-I control valve, 8-kiln hood burner or dore furnace, 9-oxygen-enriched air pipe, 10-II control valve, 11-blender, 12-III control valve, 13-II oxygen enrichment pipe, 14-air hose, 15-IV control valve, 16-oxygen generating plant, 17-I oxygen enrichment pipe, 18-oxygen enrichment blower fan, 19-storage tank, 20-blower fan, the clean fume pipe of 21-III, the clean fume pipe of 22-IV, 23-powder feeding blower fan, 24-powder storehouse, 25-machine supplying powder, 26-powder feeding pipe, 27-V control valve.
The specific embodiment
Following structure accompanying drawing is further described embodiments of the invention:
Embodiment 1,
As shown in Figure 1; rotary kiln air distribution technique of the present invention: in coal-fired kiln; temperature in preheater or the waste heat boiler 1 is reached 90 ℃-350 ℃ exhanst gas outlet draw by being connected to fume pipe 2 on preheater or the waste heat boiler 1; send in the coupled deduster 3 through fume pipe 2; deduster 3 is removed the particle in the flue gas or dust; give recirculation blower 5 by the clean fume pipe 4 of I with flue gas again; gas recirculating fan 5 is sent to the flue gas powder feed system with flue gas through the clean fume pipe 6 of II; delivered in kiln hood burner or the dore furnace 8 by the flue gas powder feed system again; control the exhaust gas volumn that enters in kiln hood burner or the dore furnace 8 by the control valve of regulating on the flue gas pipeline, thereby carry out the shape of flame or the adjusting of position, flame high-temperature region.The flue gas powder feed system is divided into two parts with flue gas, part of smoke enters kiln hood burner or dore furnace 8 through the clean fume pipe 21 of III, realizes the exhaust gas volumn that is transported to kiln hood burner central passage is controlled by the V control valve 27 that is installed on the clean fume pipe 21 of III; Part of smoke enters the clean fume pipe 22 of the IV that links to each other with powder feeding pipe 26, and regulates the exhaust gas volumn that enters powder feeding blower fan 23 by the I control valve 7 that is installed on the clean fume pipe 22 of IV.The coal dust that is contained in 24 li in powder storehouse is sent in the powder feeding pipe 26 by machine supplying powder 25, and the coal dust that the flue gas after 23 pressurizations of powder feeding blower fan will enter in the powder feeding pipe 26 is transported to burning in kiln hood burner or the dore furnace 8; Be transported to the burning while in kiln hood burner or the dore furnace 8 at coal dust, oxygen enrichment or pure oxygen by oxygen generating plant 16 made 25%-100%, be transported in the storage tank 19 by oxygen enrichment blower fan 18 through I oxygen enrichment pipe 17, pass through again the III control valve 12 of II oxygen enrichment pipe 13, in blender 11, be mixed into 25%-40% oxygen-enriched air with blower fan 20 air that send here and that control by the IV control valve 15 on the air hose 14, be transported to kiln hood burner or dore furnace 8 uses through oxygen-enriched air pipe 9.Described deduster 3, fume pipe 2, clean fume pipe and powder feeding pipe 26 can adopt the mode of insulation or companion's heat, namely at equipment or pipeline outer wall parcel insulation material, or adopt the modes such as steam, resistance that equipment or pipeline are heated, externally dispel the heat to prevent the flue gas in equipment or the pipeline.
Realize the system of embodiment 1 rotary kiln air distribution technique, mainly consisted of by preheater or waste heat boiler 1, deduster 3, gas recirculating fan 5, kiln hood burner or dore furnace 8, blender 11, oxygen generating plant 16, oxygen enrichment blower fan 18, storage tank 19, blower fan 20 and flue gas powder feed system; Described preheater or waste heat boiler 1 connect deduster 3 through fume pipe 2, deduster 3 connects gas recirculating fan 5 through the clean fume pipe 4 of I, gas recirculating fan 5 connects the flue gas powder feed system through the clean fume pipe 6 of II, is connected the arrival end of kiln hood burner or dore furnace 8 by the flue gas powder feed system again; Described flue gas powder feed system comprise the port of export and be connected in the kiln hood burner or dore furnace 8 on powder feeding pipeline 26 and the clean fume pipe 21 of III, the arrival end of powder feeding pipeline 26 and the clean fume pipe 21 of III links to each other through the clean fume pipe 6 of three-way pipe and II, is provided with successively I control valve 7, powder feeding blower fan 23 on the powder feeding pipeline 26 and is connected to machine supplying powder 25 under the powder storehouse 24; The clean fume pipe 21 of III is provided with V control valve 27.Described oxygen generating plant 16 connects storage tank 19 through I oxygen enrichment pipe 17, be connected with oxygen enrichment blower fan 18 on the pipeline of I oxygen enrichment pipe 17, storage tank 19 connects the arrival end of blender 11 through II oxygen enrichment pipe 13, described blower fan 20 is through the arrival end of air hose 14 connection blenders 11, and the port of export of blender 11 connects the arrival end of kiln hood burners or dore furnace 8 through oxygen-enriched air pipe 9.
Embodiment 2,
As shown in Figure 2, rotary kiln air distribution technique of the present invention: in the kiln of combustion gas or fuel oil, 90 ℃ in preheater or the waste heat boiler 1-350 ℃ flue gas is drawn, be transported in the deduster 3 through fume pipe 2, particle, dust in the flue gas are removed, introduced gas recirculating fan 5 through the clean fume pipe 4 of I again; Flue gas after gas recirculating fan 5 will purify is directly delivered in kiln hood burner or the dore furnace 8 through the clean fume pipe 6 of II, control the exhaust gas volumn that enters in kiln hood burner or the dore furnace 8 by the control valve of regulating on the flue gas pipeline, thereby carry out the shape of flame or the adjusting of position, flame high-temperature region; Other part is identical with enforcement 1, and identical other partly omits.
Realize the system of embodiment 2 rotary kiln air distribution techniques, substantially the same manner as Example 1, something in common slightly.Difference: preheater or waste heat boiler 1 connect deduster 3 through fume pipe 2, and deduster 3 connects gas recirculating fan 5 through the clean fume pipe 4 of I, and gas recirculating fan 5 directly connects the arrival end of kiln hood burner or dore furnace 8 through the clean fume pipe 6 of II.