CN109824282B - Energy-saving, environment-friendly and efficient operation method of high-temperature shaft kiln for calcining high-purity magnesia - Google Patents
Energy-saving, environment-friendly and efficient operation method of high-temperature shaft kiln for calcining high-purity magnesia Download PDFInfo
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Abstract
本发明属于高纯镁砂高温竖窑生产技术领域，具体涉及一种高纯镁砂煅烧用高温竖窑节能环保高效运行的方法，其特征在于，包括保持窑内负压、形成窑口进料位置的高速气流以及提升排放烟气温度三个方面；其中保持窑内负压的方法是采用焊接结构的窑盖板；所述形成窑口进料位置的高速气流方法是采用气流形成套筒；所述提升排放烟气温度的结构包括回风风机、回风管路和热风循环进风管路。与现有技术相比，本发明的有益效果是：1）窑炉内部负压绝对值提高了500pa，较以往可减少排烟风机能耗40%。2）高温区域粘接不明显，窑炉运行寿命（清理周期）增加一倍以上。3）提高窑炉烟气排放温度50℃以上，实现了高温竖窑的节能环保高效安全运行。
The invention belongs to the technical field of high-purity magnesia high-temperature shaft kiln production, and in particular relates to a method for energy-saving, environmentally friendly and efficient operation of a high-temperature shaft kiln for calcining high-purity magnesia. and three aspects of increasing the temperature of exhaust flue gas; wherein the method of maintaining the negative pressure in the kiln is to use a kiln cover plate with a welded structure; the method of forming the high-speed airflow at the feeding position of the kiln mouth is to use airflow to form a sleeve; The structure of flue gas temperature includes return air fan, return air pipeline and hot air circulation inlet air pipeline. Compared with the prior art, the beneficial effects of the present invention are: 1) The absolute value of the negative pressure inside the kiln is increased by 500pa, which can reduce the energy consumption of the exhaust fan by 40% compared with the past. 2) The bonding in the high temperature area is not obvious, and the operating life (cleaning cycle) of the kiln is more than doubled. 3) Raise the flue gas discharge temperature of the kiln by more than 50°C, and realize the energy-saving, environmental-friendly, efficient and safe operation of the high-temperature shaft kiln.
Description
Technical Field
The invention belongs to the technical field of high-purity magnesia high-temperature shaft kiln production, and particularly relates to an energy-saving, environment-friendly and efficient operation method of a high-temperature shaft kiln for high-purity magnesia calcination.
Background
In recent years, natural magnesite is treated by a high-temperature shaft kiln calcination process in China, and the MgO quality factor of the produced natural magnesite reaches 97-98%, so that the magnesia refractory material level in China is greatly improved. The high-temperature vertical kiln for calcining the high-purity magnesite clinker is fed from the center of a kiln, most of the kilns are built by refractory bricks (2) and ramming materials (3), and a kiln shell (1) is a steel plate. According to the technical scheme, the magnesium cement ramming method comprises the following steps that (1) a feeding hopper (4) is arranged on a kiln cover (5) in a sitting mode, a distributor (6) enters the interior of a kiln at the center of the lower portion of the feeding hopper, the kiln cover (5) is of a magnesium cement ramming piece, a steel cover plate (7) is arranged on the surface layer of the magnesium cement ramming piece, the steel cover plate is made of 16 manganese, stainless steel or carbon steel, the whole upper surfaces of a refractory brick (2) and a ramming material (3) on the upper portion of the kiln are covered, and a metal anchor piece (9) is arranged in the magnesium cement ramming piece (8). Because the kiln is operated under negative pressure, the negative pressure at the kiln opening is improved, the reduction of the material pulverization rate, the particle rate and the air permeability of the kiln is facilitated, the method is an important parameter and basis for the operation of the kiln, and meanwhile, the method has a vital influence on the product quality.
At kiln drying kiln and calcination temperature raising repeatedly and the in-process of burning up, can appear states such as naked light or unusual high temperature in the kiln, make kiln lid thermal deformation, magnesium fireclay pouring body (8) drop easily, influence product quality, also cause the kiln rate of leaking out to increase simultaneously, the increase of rate of leaking out makes the inside negative pressure of kiln reduce, influence operation judgement, when increaseing the amount of smoke exhaust air, smoke exhaust temperature can reduce more, increase smoke exhaust fan's energy consumption promptly, influence energy-conserving effect.
In the calcining process of the high-purity magnesia shaft kiln, the phenomenon that materials with small particle sizes are bonded with the inner wall of the kiln also exists, and the bonding process is mainly caused when low-melting-point components contained in the materials and the air permeability of the kiln are poor and the low-melting-point components and the air permeability of the kiln occur simultaneously. The high-purity magnesite is divided according to the content of magnesium oxide, substances such as silicon dioxide and ferric oxide are low-melting substances, the phenomenon of bonding a kiln wall is easy to occur in the high-temperature calcination process, the kiln needs to be stopped and cooled for treatment after the high-purity magnesite runs for a certain time, a kiln body is damaged to a certain extent due to external force impact and changes of cold and hot temperatures in the treatment process, along with the change of components of production varieties, the more low-melting substances are contained, the more heavy the kiln is bonded, particularly, the more small-particle-size materials are generated in the high-purity magnesite sintering process, the higher the bonding rate is, and the main reasons are high-temperature burst of a ball blank, low complete ball blank rate of dry-method ball pressing, material sintering friction factors and the like due to the change of loss. Taking a certain variety of magnesia as an example, the kiln needs to be stopped after the kiln is operated for 30-60 days on average, and the quality of the treated kiln body and products is affected, thereby bringing serious economic burden to enterprises.
In addition, the high-temperature shaft kiln also has the characteristics of high sintering temperature (1900-2000 ℃) and low smoke discharge temperature (70-150 ℃), the emission of pollutant Nitrogen Oxide (NOX) is far higher than that of other industries, the content of a single kiln is 3500mg/m3, and the working condition of the emission of smoke is 35000m3For the environment-friendly technology with high denitration efficiency, the smoke discharge temperature is required to be higher than 280 ℃, and the smoke discharge amount is in direct proportion to the investment cost of denitration equipment, which brings great inconvenience to enterprises in environmental managementThe heating furnace and other devices bring great economic burden to enterprises.
For a high-temperature shaft kiln, the necessary conditions of low cost and high-efficiency operation are to ensure the effective operation of each energy-saving link and the smoke environment-friendly treatment equipment in the kiln, and the defects still exist in the prior art.
Disclosure of Invention
The invention aims to provide a method for the energy-saving, environment-friendly and efficient operation of a high-temperature shaft kiln for calcining high-purity magnesia, which overcomes the defects of the prior art and solves the problems of reduced negative pressure in the kiln and increased air leakage rate caused by the fact that a kiln cover plate is deformed by heating and even disintegrates and falls off in the repeated temperature raising and reverse burning processes of kiln drying and calcining; the probability of small-particle-size materials gathering and adhering to the inner wall of the kiln in the calcining process of the kiln is reduced, the period of kiln shutdown cleaning is prolonged, and the damage to the kiln body is avoided; the method has the advantages of improving the kiln flue gas emission temperature by over 50 ℃, reducing the flue gas emission amount, facilitating the subsequent denitration treatment of the kiln flue gas, reducing the operation cost of environment-friendly equipment, ensuring smooth production and responding to the national energy-saving emission-reducing environment-friendly policy.
In order to achieve the purpose, the invention is realized by the following technical scheme:
a method for high-temperature shaft kiln energy-saving, environment-friendly and efficient operation for high-purity magnesia calcination is characterized by comprising three aspects of maintaining negative pressure in a kiln, forming high-speed airflow at a feeding position of a kiln opening and improving the temperature of discharged flue gas; the method for keeping the negative pressure in the kiln comprises the steps that a kiln cover plate with a welded structure is adopted, the kiln cover plate comprises a steel cover plate, an outer sleeve, an inner sleeve and a sealing plate, the outer sleeve and the inner sleeve are concentrically arranged on the lower surface of the steel cover plate, the bottom of the outer sleeve is connected with the sealing plate, a heat-insulating interlayer is enclosed among the steel cover plate, the outer sleeve, the inner sleeve and the sealing plate, the kiln cover plate is sealed between a kiln opening and a distributor of the high-temperature shaft kiln, a refractory material bonding layer with the thickness of 5-20 mm is arranged between the kiln cover plate and the upper surface of the kiln opening and between the kiln cover plate and the inner wall of the kiln, the opening in the lower part of the kiln opening is communicated with a flue, and a flue induced draft fan is started to keep the negative pressure value in the kiln within-150 pa to-400 pa; the high-speed airflow method for forming the kiln inlet feeding position adopts an airflow forming sleeve, the airflow forming sleeve is upwards connected to the bottom of a kiln cover plate and downwards extends to a position 150-250 mm below the bottom edge of a parallel distributing device, the high-speed airflow starts from a gap between the kiln cover plate and the distributing device and downwards flows through an air duct I between the distributing device and the airflow forming sleeve, enters the air duct from the bottom of the air duct I to form an air duct II between the outer wall of the sleeve and the inner wall of the kiln, and is finally discharged from a flue along a minimum resistance air duct route between the air duct I and the flue, and the speed of the high-speed airflow is 10.8-15.8 m/s; the structure for improving the temperature of the discharged flue gas comprises a return air fan, a return air pipeline and a hot air circulation air inlet pipeline, wherein a hole is formed in a flue and is connected with one end of the return air pipeline, the other end of the return air pipeline is connected with a suction inlet of the return air fan, an output port of the return air fan is connected with the hot air circulation air inlet pipeline, the hot air circulation air inlet pipeline is an annular pipeline, the annular pipeline is communicated with a gap between a kiln cover plate and a distributor in a continuous or discontinuous mode, and the temperature of the flue gas is 120-320 ℃.
Further, the return air pipeline is arranged vertically upwards.
Furthermore, the flue is connected to the outer side of the accident exhaust port on the kiln port and communicated with the flue gas denitration treatment equipment.
Furthermore, the ratio of the effective sectional area of the first air channel to the sectional area of the flue is 1: 4-1: 3.
Furthermore, the ratio of the effective sectional area of the second air flue to the sectional area of the flue is 3: 1-2: 1.
Furthermore, the refractory material bonding layer is made of 200-mesh magnesium fire clay and water glass.
Further, the air flow forming sleeve and the inner sleeve are of an integral structure.
Further, gaps except for the joint of the annular pipeline and the gap are sealed by refractory materials.
Furthermore, the discontinuous form is that 3-4 circular or oblate pipelines are connected.
Further, the output total pressure of the return air fan is 1464 Pa-1621 Pa.
Compared with the prior art, the invention has the beneficial effects that:
1) the problems that in the repeated temperature raising and reverse burning processes of kiln drying and calcining, a kiln cover is deformed by heating and even disintegrates and falls off to cause reduction of negative pressure in a kiln and increase of air leakage rate are solved, and practices prove that compared with the prior art, the absolute value of the negative pressure in the kiln is improved by 500pa, and the energy consumption of a smoke exhaust fan can be reduced by 40% compared with the prior art.
2) The probability of small-particle-size materials gathering and bonding the inner wall of the kiln in the calcining process of the kiln is reduced, the speed of hot air in the kiln is accelerated, the small-particle-size materials which are easy to bond are directly blown to a kiln opening along with the wind speed, so that the air permeability in the kiln is enhanced, the materials enter a flue to be discharged, the probability of small-particle-size bonding is reduced, in the practical application process, the bonding in a high-temperature area is not obvious, and the service life (cleaning period) of the kiln is prolonged by more than one time.
3) Because the flue gas temperature of the kiln flue is generally higher than the air temperature at the air inlet of the kiln opening, the air inlet temperature of the kiln can be effectively increased, the flue gas emission temperature of the kiln is finally increased by over 50 ℃, and the flue gas emission can be reduced by 10000m3The method has obvious effects on subsequent kiln flue gas treatment and temperature rise cost reduction, effectively reduces the operation cost, ensures smooth production, saves energy, reduces emission, has important significance in the technical field of low-temperature denitration, and finally realizes energy-saving, environment-friendly, high-efficiency and safe operation of the high-temperature shaft kiln.
Drawings
FIG. 1 is a schematic view of the structure of a mouth of a conventional high-temperature shaft kiln.
Fig. 2 is a schematic structural diagram of an implementation state of the present invention.
FIG. 3 is a schematic structural view of an embodiment of the kiln cover plate of the invention.
FIG. 4 is a schematic view of an embodiment of a hot air pipeline connecting end according to the present invention.
In the figure: 1-kiln shell, 2-refractory brick, 3-ramming mass, 4-charging hopper, 5-kiln cover, 6-distributor, 7-steel cover plate, 8-magnesium fire clay casting body, 9-metal anchor, 10-flue, 11-accident smoke outlet, 12-observation door, 13-high-purity magnesia, 14-semi-finished product light-burned magnesium ball, 15-kiln cover plate, 16-steel cover plate, 17-outer sleeve, 18-inner sleeve, 19-sealing plate, 20-heat-insulating interlayer, 21-refractory material bonding layer, 22-airflow forming sleeve, 23-return air fan, 24-return air pipeline, 25-hot air circulation inlet pipeline, 26-reinforced flange ring and 27-smoke exhaust fan.
Detailed Description
The preparation process of the present invention is further illustrated by the following examples:
in the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; may be directly connected or indirectly connected through an intermediate. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
Referring to fig. 2 and 3, the structure of the invention is schematically shown in the implementation state, a kiln opening is built by refractory bricks 2 and ramming materials 3, and the outside of the ramming materials 3 is covered with a kiln shell 1 made of steel plates. The inner side of the kiln mouth part is provided with a flue 10, the position opposite to the flue is provided with an observation door 12, the flue 10 is connected to an accident smoke outlet 11 of the kiln mouth, and the flue 10 is connected with a subsequent dust removal and desulfurization system for flue gas treatment. The upper part of the distributing device 6 is connected with an upper hopper 4, a semi-finished product light-burned magnesium ball 14 is contained in the upper hopper 4, the semi-finished product light-burned magnesium ball 14 enters a kiln opening of the high-temperature shaft kiln through the bottom of the distributing device 6, and the semi-finished product light-burned magnesium ball 14 is fired at high temperature to obtain high-purity magnesia 13. The invention relates to a method for energy-saving, environment-friendly and efficient operation of a high-temperature shaft kiln for calcining high-purity magnesia, which mainly comprises the three aspects of maintaining negative pressure in the kiln, forming high-speed airflow at a feeding position of a kiln opening and improving the temperature of discharged flue gas.
The method for keeping the negative pressure in the kiln adopts the kiln cover plate 15 with a welded structure, the kiln cover plate comprises a steel cover plate 16, an outer sleeve 17, an inner sleeve 18 and a sealing plate 19, the outer sleeve 17 and the inner sleeve 18 which are concentrically arranged are connected to the lower surface of the steel cover plate 16, the sealing plate 19 is connected to the bottom of the outer sleeve, a heat-insulating interlayer 20 is enclosed among the steel cover plate 7, the outer sleeve 17, the inner sleeve 18 and the sealing plate 19, and heat-insulating rock wool is filled in the heat-insulating interlayer 20, so that the influence of high temperature in the kiln on the steel cover plate is reduced, and the phenomenon that the air leakage and the negative pressure in the kiln are damaged due to high-temperature deformation of the steel cover plate 7 is avoided.
The kiln cover plate 15 is covered between a kiln opening and a distributing device of the high-temperature shaft kiln in a sealing mode, a refractory material bonding layer 21 with the thickness of 8-10 mm is arranged between the kiln cover plate and the upper surface of the kiln opening and between the kiln cover plate and the inner wall of the kiln, an opening in the lower portion of the kiln opening is communicated with the flue 10, a smoke exhaust fan 27 of the flue 10 is opened, the negative pressure value in the kiln is kept between-150 pa and-500 pa, and the negative pressure environment can guarantee the stability of the raw material calcining process. The structure has the advantages that the installation mode of the feeding hopper 4 and the distributing device 6 is not influenced, and the leakage of smoke is reduced to the maximum extent. In the embodiment, the refractory bonding layer is made of 200-mesh magnesium fire clay and water glass.
The high-speed airflow method for forming the kiln inlet feeding position adopts an airflow forming sleeve 22, the airflow forming sleeve 22 is upwards connected to the bottom of a kiln cover plate 15 and downwards extends to a position, where H is 250mm, below the bottom edge of a parallel distributing device, high-speed airflow starts from a gap between the kiln cover plate 15 and the distributing device 6 and downwards flows through a gap between the distributing device 6 and the airflow-shaped sleeve 22 (namely an air duct I28), then enters the air duct from the bottom of the air duct I28 to form a gap between the outer wall of the sleeve and the inner wall of the kiln (namely an air duct II 29), and finally is discharged from a flue along a minimum resistance air duct route between the air duct I28 and the flue, the high-speed airflow speed is 13 m/s-15 m/s, and the effective sectional area of the air duct I28 is 1 of the sectional area of the flue 10: 4, the effective sectional area of the second air duct 29 is 2.5 of the sectional area of the flue 10: preferably 1. The small-particle-size materials entering the kiln from the distributor 6 cannot be gathered under the blowing of the air flow and are directly discharged from the flue, so that the service life of the kiln is prolonged. To avoid failure of the flow-forming sleeve 22 due to deformation at high temperatures and impact of the magnesite balls, the bottom of the flow-forming sleeve 22 is provided with a reinforcing flange ring 26, and the reinforcing flange ring 26 is welded to the outer wall of the flow-forming sleeve 22 with full or spaced welds.
The method for increasing the temperature of the discharged flue gas comprises a return air fan 23, a return air pipeline 24 and a hot air circulation air inlet pipeline 25, wherein the return air pipeline 24 and the hot air circulation air inlet pipeline 25 are vertically arranged upwards, an opening in a flue 10 is connected with one end of the return air pipeline 24, the other end of the return air pipeline 24 is connected with a suction inlet of the return air fan 23, an output port of the return air fan 23 is connected with the hot air circulation air inlet pipeline 25 through a pipeline, the output total pressure of the return air fan 23 is 1464 Pa-1621 Pa, and the negative pressure state in a kiln can be still ensured while the hot air circulation is realized. The heated air circulation air inlet pipeline 25 is an annular pipeline, and a gap between the heated air circulation air inlet pipeline 25 and the kiln cover plate 15 and the distributing device 6 is communicated in a discontinuous 4-circular pipeline mode, as shown in fig. 4, in order to reduce the entering of cold air, a gap outside a joint between the heated air circulation air inlet pipeline 25 and the kiln cover plate and the distributing device is blocked by a refractory material, and the temperature of flue gas is raised to 120-320 ℃ from the original 70-150 ℃, so that the efficient operation of the subsequent denitration equipment of the kiln is ensured.
In the embodiment, the steel cover plate 16, the outer sleeve 17, the inner sleeve 18, the closing plate 19 and the air flow forming sleeve 22 are made of hydrogen sulfide corrosion resistant steel, such as: and the steel plates with the grades of Q245R (HIC), Q345R (HIC), SA516Gr70 (HIC) and the like are used for meeting the strength requirement under the conditions of high temperature and high abrasion.
The embodiments described above are merely specific examples selected for illustrating the objects, technical solutions and advantages of the present invention in detail, and should not be construed as limiting the scope of the present invention, and various modifications, equivalent substitutions and improvements can be made without departing from the spirit and principle of the present invention.
Claims (9)
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| CN201910202621.0A CN109824282B (en) | 2019-03-18 | 2019-03-18 | Energy-saving, environment-friendly and efficient operation method of high-temperature shaft kiln for calcining high-purity magnesia |
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| CN201910202621.0A CN109824282B (en) | 2019-03-18 | 2019-03-18 | Energy-saving, environment-friendly and efficient operation method of high-temperature shaft kiln for calcining high-purity magnesia |
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| CN112414108B (en) * | 2020-12-04 | 2023-01-06 | 广西柳钢新材料科技有限公司 | Sealing device for ash discharge conical hopper of Maerz kiln |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0531130A2 (en) * | 1991-09-04 | 1993-03-10 | Dresser Industries Inc. | Improved magnesite-spinel refractory product and method for making same |
| CN105294117A (en) * | 2014-06-06 | 2016-02-03 | 上海梅山钢铁股份有限公司 | Gunning material for outer wall lining of lime kiln heat-exchanger |
| CN106495508A (en) * | 2016-10-13 | 2017-03-15 | 辽宁劲达华杰工程技术有限公司 | A kind of environmental protection and energy saving light calcined magnesia calcining kiln |
| CN107892493A (en) * | 2017-12-15 | 2018-04-10 | 中冶焦耐(大连)工程技术有限公司 | An electric heating shaft kiln and light-burned magnesia production process based on it |
| CN108168292A (en) * | 2017-11-29 | 2018-06-15 | 方国庆 | A kind of multifunction environment-protection type BSK sintering technologies shaft furnace and its application method |
| CN108863114A (en) * | 2018-07-06 | 2018-11-23 | 沈阳化工大学 | A kind of method that the light-burned process waste heat of magnesite recycles |
| CN109437607A (en) * | 2019-01-11 | 2019-03-08 | 于景坤 | A kind of preparation method of high-density sintered magnesia |
-
2019
- 2019-03-18 CN CN201910202621.0A patent/CN109824282B/en not_active Expired - Fee Related
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0531130A2 (en) * | 1991-09-04 | 1993-03-10 | Dresser Industries Inc. | Improved magnesite-spinel refractory product and method for making same |
| CN105294117A (en) * | 2014-06-06 | 2016-02-03 | 上海梅山钢铁股份有限公司 | Gunning material for outer wall lining of lime kiln heat-exchanger |
| CN106495508A (en) * | 2016-10-13 | 2017-03-15 | 辽宁劲达华杰工程技术有限公司 | A kind of environmental protection and energy saving light calcined magnesia calcining kiln |
| CN108168292A (en) * | 2017-11-29 | 2018-06-15 | 方国庆 | A kind of multifunction environment-protection type BSK sintering technologies shaft furnace and its application method |
| CN107892493A (en) * | 2017-12-15 | 2018-04-10 | 中冶焦耐(大连)工程技术有限公司 | An electric heating shaft kiln and light-burned magnesia production process based on it |
| CN108863114A (en) * | 2018-07-06 | 2018-11-23 | 沈阳化工大学 | A kind of method that the light-burned process waste heat of magnesite recycles |
| CN109437607A (en) * | 2019-01-11 | 2019-03-08 | 于景坤 | A kind of preparation method of high-density sintered magnesia |
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