CN215102889U - Double-hearth lime kiln for realizing parallel-flow countercurrent synchronous calcination and denitration in furnace - Google Patents
Double-hearth lime kiln for realizing parallel-flow countercurrent synchronous calcination and denitration in furnace Download PDFInfo
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- CN215102889U CN215102889U CN202121694962.3U CN202121694962U CN215102889U CN 215102889 U CN215102889 U CN 215102889U CN 202121694962 U CN202121694962 U CN 202121694962U CN 215102889 U CN215102889 U CN 215102889U
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Abstract
The utility model discloses a two thorax limekilns for realizing denitration in cocurrent flow calcines and stove against current, two thorax limekilns carry out two segmentation through the main heating spray gun that sets up multiunit coal-electricity sharing or gas-electricity sharing and assist with hot spray gun system and calcine at first kiln thorax and second kiln thorax inside, and the heat energy conversion circulation of annular passage through first kiln thorax and second kiln thorax makes the heat energy distribution more even, production is controlled more conveniently, product quality changes the control. Not only realizes the automatic ignition of the spray gun and the accurate control of the calcining temperature, but also achieves the purposes of using clean energy sources such as electric energy and the like and using low-calorific-value fuel. The utility model discloses make the heat accumulation kiln thorax possess the function of calcining in the heat accumulation, make lime calcination time longer, effectively improved kiln volume utilization coefficient and calcination efficiency, can promote 30-40% productivity at least, still realized simultaneously carrying out the purpose of denitration in the stove, reduced the emission of carbon emission and pollutant promptly, also reduced the environmental protection device investment.
Description
Technical Field
The utility model relates to a chemical industry equipment technical field, concretely relates to a two thorax limekilns that is used for realizing that parallel flow is synchronous to be calcined against current and denitration in stove.
Background
The parallel-flow heat accumulating type double-chamber lime kiln is widely popularized all over the world due to the unique energy-saving advantage, and the double-chamber lime shaft kiln has been developed for more than 60 years so far. The parallel-flow heat accumulating type double-hearth lime kiln has a unique double-hearth structure, the two hearths of the parallel-flow heat accumulating type double-hearth lime kiln can alternately realize the functions of calcining and heat accumulating, and can realize the highest lime activity and the lowest fuel consumption, so that the parallel-flow heat accumulating type double-hearth lime kiln has incomparable technological advantages compared with other lime kilns.
From the technical development process of the double-chamber lime kiln, the production principle is mostly the same: the lime calcining kiln consists of two vertical calcining hearths which are communicated with each other and alternately calcine lime, the two kiln bodies are provided with reversing systems for alternately using the two kiln bodies, the lower parts of the calcining belts of the kiln bodies are provided with channels which are communicated with each other, and the pulverized coal or gas spray gun is arranged in a preheating belt and is embedded in limestone in an inserting manner. The annular channel is additionally arranged between the calcining zone and the cooling zone, and the flue gas connecting channel is arranged between the annular channels of the two shaft kilns, so that parallel flow type calcining is realized, the efficiency of the lime shaft kiln is improved, and the energy consumption of lime production is favorably reduced. The co-current flow in the double-hearth shaft kiln means that when the limestone is calcined by burning coal powder or coal gas, the combustion products and the lime flow downward in the same direction and in parallel.
The heat accumulation means that high-temperature waste gas generated by combustion enters the other kiln chamber from one kiln chamber through an annular channel at the lower part of the two kiln chambers and flows upwards, namely the heat accumulation means that limestone in a preheating zone at the upper part of the kiln is preheated to a higher temperature through 'countercurrent', and heat is accumulated. At this time, the high-temperature exhaust gas is discharged out of the kiln chamber after the temperature of the high-temperature exhaust gas is reduced to a very low value.
As can be seen from the production principle, the existing parallel-flow heat accumulating type double-hearth lime kiln has the advantages of fully utilizing high-temperature waste gas, saving energy and protecting environment. But the disadvantages are also obvious: because two kilns exchange and calcine, when one hearth is parallel-flow and calcine, the other hearth needs the same time to stop calcining and carry out countercurrent heat storage, generally, two kilns are reversed every 15 minutes, which causes the actual calcining time of each kiln to be only 50%, and is also an important reason that the volume utilization coefficient of the existing double-hearth lime shaft kiln is not high compared with other kiln types and the investment per ton product is high.
Meanwhile, the double-hearth shaft kiln has outstanding limitation on fuel selection, various indexes are optimal when coal injection production is carried out by adopting high-calorific-value coal fuel, and various indexes are obviously reduced when low-calorific-value fuel is used. Especially when gas is used for production, the calorific value of the fuel gas is required to be more than 1500kcal/m3The high heat value gas can be used for producing the product, and the most common and easily obtained industrial tail gas used for producing lime in the metallurgical industry is the blast furnace gas, the heat value of which is only 750kcal/m3And the yield coefficient is lower, and the production coefficient can only reach about 60 percent compared with the production by adopting coal injection fuel under the same kiln volume. Furthermore, the high calorific gas currently available for lime kilns is becoming less and less, and in order to try for the production of lime kilns, it is necessary to consider low calorific gas for the production of metallurgical lime.
The traditional double-hearth lime kiln also has the defects of difficult ignition of a spray gun and difficult operation, the spray gun needs to be manually ignited when the temperature of an ignition point in the kiln hearth cannot be reached, but because the spray gun is buried in the position of a calcining zone in the kiln, and facilities such as a manhole and the like cannot be installed on the calcining zone of the furnace body, the ignition of the spray gun is extremely difficult to operate, the ignition can be realized by manual naked flame after more than half of the material level in the furnace is reduced to expose a spray gun nozzle, and the production operation and the safety are greatly influenced. Although a plurality of groups of ignition devices are installed at the position of a burning zone spray gun outside a furnace body in the prior art, the problems of potential safety hazard and difficult operation exist because gas such as natural gas is required to be used as ignition fuel. Denitration refers to a process for removing nitrogen oxides from combustion flue gas, generally speaking, in a lime kiln calcining zone, the temperature of a hearth is as high as 950-1100 ℃, the instantaneous temperature can even exceed 1200 ℃, and under the temperature condition, no matter what fuel is used, a large amount of NOx can be generated. The smoke is the main emission of the lime kiln, and the smoke has to be subjected to denitrification treatment before being discharged, because the smoke contains a large amount of nitrogen oxides NOX such as NO, and the nitrogen oxides can pollute the air and form photochemical smog and acid rain if being directly discharged into the atmosphere, so that the human health is harmed. At present, the flue gas denitration technology mainly has two kinds: selective Catalytic Reduction (SCR) technology and selective non-catalytic reduction denitration (SNCR) technology. The SCR technology is originated and matured in the power industry and is a mature high-efficiency denitration technology at present. However, the existing technology cannot be really applied to the lime industry, and the main reasons are that the production process is not applicable, the operation cost is too high, the occupied area is large, the investment is too high, and the like.
In conclusion, how to realize parallel flow and reverse flow whole-course calcination, improve the utilization coefficient of the kiln volume, how to improve the method and the device for adopting low-heat value fuel gas and low-heat value solid fuel in the double-hearth lime shaft kiln, so that the method and the device are suitable for the double-hearth lime shaft kiln, and the technical problems to be solved are urgently needed to research a safe, reliable and convenient spray gun ignition device and a denitration double-hearth kiln for realizing low-cost operation and ultralow emission.
SUMMERY OF THE UTILITY MODEL
Therefore, the utility model provides a two thorax limekilns for realizing that parallel flow calcines and denitration in the stove in step against current.
In order to achieve the above object, the present invention provides the following technical solutions:
the utility model provides a double-chamber limekiln for realizing parallel-flow countercurrent synchronous calcination and denitration in a furnace,
the double-hearth lime kiln comprises a first hearth and a second hearth, a first annular gas channel is arranged at the bottom of the first hearth, a second annular gas channel is arranged at the bottom of the second hearth, and the first annular gas channel is communicated with the second annular gas channel;
the preheating zone at the upper part of the first hearth kiln is provided with a plurality of first main heating spray guns, and the preheating zone at the upper part of the second hearth kiln is provided with a plurality of second main heating spray guns;
a plurality of first auxiliary heating thermal guns are arranged in the first annular gas channel, and a second auxiliary heating thermal gun is arranged in the second annular gas channel;
the first main heating spray gun and the second main heating spray gun respectively comprise a spray gun fuel spray pipe, a first electric heating device, an inner heat insulation protective sleeve and an outer protective sleeve, the inner heat insulation protective sleeve and the outer protective sleeve are arranged on the outer side of the spray gun fuel spray pipe, a cavity is formed between the inner heat insulation protective sleeve and the outer protective sleeve, and the first electric heating device is arranged in the cavity;
the first auxiliary heating spray gun and the second auxiliary heating spray gun respectively comprise a high-pressure air spray pipe, an inner side protective sleeve, an outer side protective sleeve, a second electric heating device and a high-pressure air releasing device;
the high-pressure air spraying pipe is characterized in that the inner side protective sleeve and the outer side protective sleeve are arranged on the outer side of the high-pressure air spraying pipe, a second electric heating device is arranged between the inner side protective sleeve and the outer side protective sleeve, and the high-pressure air releasing device is communicated with the high-pressure air spraying pipe.
Preferably, first distributing device is arranged on the upper portion of the first hearth kiln, a second distributing device is arranged on the upper portion of the second hearth kiln, and the first distributing device and the second distributing device are connected with the receiving hopper through electro-hydraulic material distributors respectively.
Preferably, the double-hearth lime kiln further comprises a first flue gas regulating and controlling device and a second flue gas device, wherein the first flue gas regulating and controlling device is connected with the distributing device through a first waste gas pipeline, is connected with the first hearth kiln through a third waste gas pipeline, and is connected with the dust removing device through a first waste gas main channel;
the second flue gas device is connected with the distributing device through a second waste gas pipeline, connected with the second hearth kiln through a fourth waste gas pipeline and connected with the dust removal device through a second waste gas main channel.
Preferably, the upper parts of the first hearth kiln and the second hearth kiln are respectively provided with a denitration agent input interface.
Preferably, the bottom of the first hearth kiln is provided with a first discharging device, and the bottom of the second hearth kiln is provided with a second discharging device.
Preferably, a first cooling air pipeline is arranged at the first discharging device, and a second cooling air pipeline is arranged at the second discharging device.
Preferably, a first discharging device is arranged at the lower part of the first discharging device, and a second discharging device is arranged at the lower part of the second discharging device.
Preferably, the double-hearth lime kiln further comprises a discharge bin, and outlets of the first discharge device and the second discharge device are connected with the discharge bin.
Preferably, the bottom of the discharging bin is also provided with an ash discharging device connected with the discharging bin.
The utility model discloses the abundant main characteristic of heating spray gun and the auxiliary heating spray gun of utilizing first thorax kiln and second thorax kiln utilizes spray gun fuel spray tube as the structure skeleton in the functional structure principle of keeping spray gun jetting solid fuel and gas fuel, sets up high temperature resistant material as thermal-insulated protective layer in the spray gun pipe outside, sets up electric heating material in the outside suitable position of inboard insulating layer, and the high temperature resistant material of electric heating material externally mounted and resistant scouring material are as outer protective sheath. And the heat-resisting material and the electric heating material outside the spray gun are combined materials which can be disassembled and assembled in sections, so that the whole spray gun device has multiple functions and multiple purposes. The spray gun can independently spray fuel for combustion or independently convert electric energy into calcination in the use process. Because the electric heating device is arranged on the fuel spray pipe of the spray gun, the electric heating device can be far away from the fire-spraying opening of the spray gun, so that the high-temperature ablation is reduced. Meanwhile, the electric energy conversion device is only used when the heat storage chamber works, and the temperature of the electric energy conversion device can be adjusted within the tolerable temperature. And when the combustion chamber works, the electric energy conversion heating device is closed and carries out cooling exchange with combustion air blown in from the upper part of the combustion chamber.
The utility model discloses a reaction principle of denitration in stove does: according to the principles of Brownian motion and intermolecular force, the introduction of the reducing agent makes the molecular chemical bond of the high-temperature and high-pressure steam very weak, and the chemical bond reacts with carbon to generate carbon monoxide and hydrogen: c + H2O＝CO+H2(ii) a Carbon monoxide and hydrogen participate in two chemical reactions: CO +2NO ═ CO2+N2And 2H2+2NO＝2H2O+N2(ii) a Part of the reducing gas generated by the reaction of the hydrogen and the nitrogen reacts with the nitric oxide to be reduced into the nitrogen: n is a radical of2+3H2＝2NH3And 6NO +4NH3＝5N2+6H2And O, so that the nitrogen oxides are completely reduced, and the aim of low-cost denitration is fulfilled. The utility model alsoThe raw agent adopts urea as a reducing agent, so that the denitration effect is better, and no secondary emission pollution of water and gas and no solid waste is generated. The utility model adopts the comprehensive application of gas phase method and liquid phase method to convey the medium into the furnace by the original power system in the lime kiln production, and the medium is activated and vaporized in the furnace, and is subjected to chemical reaction with NOx in the twinkling of an eye to be reduced into N2And H2And O. The treatment process adopts a step treatment method, skillfully utilizes sufficient airflow retention time generated by reverse exchange between stone and airflow when the lime kiln heat storage chamber descends in the heat storage process to carry out NOx reduction reaction, can control the combustion process on a NOx generation source to reduce the content of NOx, and has stronger temperature selectivity so as to ensure simpler operation. The reducing atmosphere in the furnace is uniform, the pressure is stable, the resistance is small, and the denitration reducing zone is arranged in an area which is poor in oxygen and rich in fuel, thereby being beneficial to reducing the nitrogen in the fuel to form NOx(i.e. fuel type NO)x). Meanwhile, the technology does not need to increase large-scale external investment equipment such as a denitration tower, a reactor and the like, realizes direct denitration in the lime kiln, fully utilizes waste heat in the production of the lime kiln, and does not need energy consumption cost increased by external heating.
The utility model discloses a first thorax kiln volume second thorax kiln adopts per 15min or other settlement time commutations to calcine, is in the malleation state all the time when calcining the kiln thorax and calcining. High-pressure combustion-supporting air is blown into a preheating zone of a kiln chamber by a combustion-supporting fan, and the combustion-supporting air flows downwards and is preheated by hot limestone in the preheating zone. When the preheated combustion-supporting air reaches the calcining zone, the preheated combustion-supporting air is mixed with the fuel such as coal powder conveyed by the spray gun and the like and is violently combusted. The fuel flows downward, i.e., co-current, with the hot gases from the combustion of air and the limestone after the heat absorption. The co-current combustion method enables direct contact of the combustion flame with the raw material limestone and calcination of the limestone and gradual decomposition thereof with high heat exchange efficiency. When the partially decomposed limestone reaches the upper end of the annular channel, the temperature of the combustion waste gas is relatively reduced, then a plurality of groups of electric heating devices arranged in the annular channel fully release heat to heat the combustion waste gas, the heated waste gas flows to another heat storage kiln chamber through the joint of the annular channel of the first kiln chamber and the second kiln chamber, the flow speed of the waste gas is derived from the pressure in the calcining kiln chamber, and the pressure at the annular channel is in the range of 15-25 Kpa. At the moment, the pressure in the heat storage kiln chamber is lower than that of the calcining chamber, so that the high-temperature waste gas rises from bottom to top, passes through the calcining zone to reach the preheating zone, contacts with limestone in the preheating zone and exchanges heat.
When the calcining chamber is calcined, the main heating spray gun of the heat storage chamber is closed, the combustion-supporting air is also closed, and the whole calcining zone of the heat storage chamber is not combusted. At this time, the electric heater provided around the main heating lance starts heating, and contacts the limestone in the preheating zone together with the rising exhaust gas to perform heat exchange. After the heat of the electric heating device and the waste heat of the waste gas are fully released to the limestone, the waste gas continuously rises to release the waste heat with stone newly put into the upper part of the preheating zone, and when the waste gas passes through a kiln top bin, the waste gas and the cold limestone in the bin are continuously released fully, so that the temperature of the waste gas is reduced to the range of 80-140 ℃ and then the waste gas is discharged out of the kiln.
The utility model has the advantages of as follows:
the utility model provides the high volume coefficient has increased the productivity, and two thorax cocurrent flow calcine in countercurrent and not take an effect of the calcination efficiency who has improved the calcination kiln thorax, make the heat accumulation kiln thorax possess the function of calcining in addition when the heat accumulation, make limestone calcination time longer, the volume coefficient of utilization higher, can promote 30-40% productivity at least.
The utility model discloses a production is controlled more conveniently, product quality changes and is controlled, owing to use the electric energy heating to carry out the secondary and calcine, makes the kiln in calcine the temperature and adjust the control more easily, and heat distribution is more balanced, can realize temperature automatic control and the regulation of high accuracy, can the accurate control heat load with calcine the temperature, make the lime stone decompose more fully, more even, improved the lime quality.
The utility model discloses reduced the use of the traditional energy, increased the use of clean energy, owing to utilize the electric energy to carry out secondary auxiliary heating and calcine, realized coal-electricity integration production, reduced the use of traditional fuels such as coal, reduced the emission of carbon emission and pollutant.
The utility model discloses make full use of low heat value energy, further reduction in production cost because electric energy heating adopts two sections to calcine the mode, and electric energy heating divides two sections to go on, and the temperature can promote twice, consequently not high to the requirement of fuel, can use the solid fuel of low heat value and the gas fuel of low heat value
The utility model discloses reduced comprehensive energy consumption and investment, because the electric energy heating is the anaerobic combustion, the terminal part of heating region at heat accumulation flue gas flow in-process, consequently the content of surplus air in the waste gas very reduces, and the heat consumption is lower. Meanwhile, the electric energy heating does not need air to support combustion, the total amount of gas in the kiln and the kiln pressure can be greatly reduced, the demand for combustion-supporting air blown in from the preheating zone is greatly reduced, the power consumption and the power index of a combustion-supporting fan, a lime cooling fan, a spray gun cooling fan, a coal gas pressurizer and a dust removal draught fan are greatly reduced, and the electric energy and the investment are saved.
The utility model discloses realize denitration in the stove, reduce the environmental protection facility investment, because the electric heating region carries out the denitration improvement in the stove, make the denitration facility simple and practical more, reduced the investment of the denitration facility outside the stove, make the environmental protection investment more economical and practical. Meanwhile, when denitration is carried out in the furnace, the clearance when the hearth storage spray gun stops burning is adopted for spraying, and the spraying effect is achieved after the spraying gun and cooling air are mixed, so that the aims of denitration and cooling are achieved.
The utility model discloses need not to increase the heat accumulator, realized the electric energy storage function, carry out the energy storage as solid heat accumulator material the lime stone, need not increase the exothermic medium of heat accumulation, realize electric energy conversion and heat accumulation heating integration function.
The utility model discloses realize that the spray gun freely ignites, it is convenient to use the regulation and control safely, carries out high temperature ignition through the electric heater unit who adopts on the spray gun device, and easy operation safety is convenient, and temperature adjustable is controllable moreover, can operate in the different operating modes in production.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. It should be apparent that the drawings in the following description are merely exemplary, and that other embodiments can be derived from the drawings provided by those of ordinary skill in the art without inventive effort.
The structure, ratio, size and the like shown in the present specification are only used for matching with the content disclosed in the specification, so as to be known and read by people familiar with the technology, and are not used for limiting the limit conditions which can be implemented by the present invention, so that the present invention has no technical essential significance, and any structure modification, ratio relationship change or size adjustment should still fall within the scope which can be covered by the technical content disclosed by the present invention without affecting the efficacy and the achievable purpose of the present invention.
FIG. 1 is a schematic structural diagram of a dual-chamber lime kiln for implementing cocurrent and countercurrent synchronous calcination and denitration in a furnace according to an embodiment of the present invention;
fig. 2 is a schematic structural view of a first main heating spray gun and a second main heating spray gun provided by the embodiment of the present invention;
fig. 3 is a schematic structural diagram of a first auxiliary heating spray gun and a second auxiliary heating spray gun according to an embodiment of the present invention;
in the figure: a first chamber kiln-1; a second chamber kiln-2; a receiving hopper-3; an electrohydraulic distributor-4; a first distributor-5; a second distributor-6; a first main heating spray gun-7; a second main heating spray gun-8; a first auxiliary heating lance-9; a second auxiliary heating lance-10; a first discharging device-11; a second discharge device-12; a first discharge device-13; a second discharge device-14; a discharge bin-15; an ash discharge device-16; a first exhaust conduit-17; a second exhaust conduit-18; third waste gas pipeline-19; a fourth exhaust conduit-20; a first flue gas regulation and control device-21; a second flue gas regulation and control device-22; a first main exhaust gas channel-23; a second main exhaust gas channel-24; a first cooling air duct-25; a second cooling air duct-26; a first annular gas passage-27; an annular channel connection port-28; a second annular gas passage-29; a denitrifier input interface-30; lance fuel nozzle-201; a heat insulation protective sleeve-203 is arranged in the fuel nozzle-202; an outer protective sheath-204; a first electric heating means-205; high-pressure air nozzle-301; heating the device body-302; an inner protective sheath-303; outer protective sheath-304; second electric heating means-305 second electric heating means inlet 306; high pressure air release device-307.
Detailed Description
The present invention is described in terms of specific embodiments, and other advantages and benefits of the present invention will become apparent to those skilled in the art from the following disclosure. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.
As shown in fig. 1, the utility model provides a two thorax limekilns for realizing denitration in cocurrent flow countercurrent synchronous calcination and stove, two thorax limekilns include first thorax 1 and second thorax kiln 2, first thorax 1 and second thorax kiln 2 are the vertical structure thorax of two parallels, every thorax all has the kiln shell that the steel construction is constituteed and the insulating layer of constituteing by refractory material, the upper portion of first thorax 1 and second thorax kiln 2 is the preheating zone, the thorax middle part is the calcining zone, calcining zone lower part has first annular gas passageway 27 and second annular gas passageway 29 with two thorax intercommunications, the thorax lower part is the cooling zone.
The bottom of the first hearth kiln 1 is provided with a first annular gas channel 27, the bottom of the second hearth kiln 2 is provided with a second annular gas channel 29, and the first annular gas channel 27 is communicated with the second annular gas channel 29; a plurality of first main heating spray guns 7 are arranged in the preheating zone at the upper part of the first hearth kiln 1, and a plurality of second main heating spray guns 8 are arranged in the preheating zone at the upper part of the second hearth kiln 2; a plurality of first auxiliary heating lances 9 are provided in the first annular gas passage 27, and a second auxiliary heating lance 10 is provided in the second annular gas passage 29.
As shown in fig. 2, each of the first main heating spray gun 7 and the second main heating spray gun 8 includes a spray gun fuel spray pipe 201, a first electric heating device 205, an inner heat insulation protective sleeve 203 and an outer protective sleeve 204, the inner heat insulation protective sleeve 203 and the outer protective sleeve 204 are disposed outside the spray gun fuel spray pipe 201, a cavity is formed between the inner heat insulation protective sleeve 203 and the outer protective sleeve 204, and the first electric heating device 205 is disposed in the cavity; by utilizing the structural characteristics of the spray gun fuel spray pipe 201, under the condition that the normal solid or gas injection, injection and combustion of the fuel spray port 202 is not influenced, the inner heat insulation protective sleeve 203 and the outer protective sleeve 204 are arranged outside the spray gun fuel spray pipe 201, a heating cavity is formed between the inner heat insulation protective sleeve 203 and the outer protective sleeve 204, the inner heat insulation protective sleeve 203 and the outer protective sleeve 204 are made of high-temperature-resistant industrial ceramics, and a multi-section structure can be adopted to prevent bending deformation and facilitate replacement. The electric heating material is arranged in the heating cavity to achieve the purpose of converting electric energy into heat energy. The temperature of the first electric heating device 205 can be arbitrarily adjusted and started and stopped. When the first electric heating device 205 is in operation, the fuel nozzles 202 automatically stop injecting fuel while injecting a small amount of air to prevent nozzle clogging and to cool the lance fuel lance 201. The nozzle end face of the spray gun fuel nozzle 201 is kept a certain distance from the working end faces of the inner heat insulation protective sleeve 203, the outer protective sleeve 204 and the first electric heating device 205 so as to prevent the influence on the components when the spray gun fuel nozzle 201 is ablated.
As shown in fig. 3, each of the first auxiliary heating lance 9 and the second auxiliary heating lance 10 includes a high-pressure air nozzle, an inner protective sheath 303, an outer protective sheath 304, a second electric heating device 305, and a high-pressure air releasing device 307; the inner protective sleeve 303 and the outer protective sleeve 304 are arranged outside the high-pressure air nozzle, a second electric heating device 305 is arranged between the inner protective sleeve 303 and the outer protective sleeve 304, and the high-pressure air releasing device 307 is communicated with the high-pressure air nozzle. The second electric heating device 305 is a key device for realizing double-bore parallel flow and countercurrent synchronous calcination, the heating device body 302 is externally provided with an inner protective sleeve 303 and an outer protective sleeve 204, a heating cavity is formed between the inner protective sleeve 303 and the outer protective sleeve 3043, the inner protective sleeve 303 and the outer protective sleeve 3043 are made of high-temperature resistant industrial ceramics, and a multi-section structure is adopted to prevent bending deformation and facilitate replacement. The heating cavity formed between the inner protective sleeve 303 and the outer protective sleeve 304 is provided with an electric heating material to achieve the purpose of converting electric energy into heat energy. The temperature of the second electric heating device 305 can be arbitrarily adjusted and started and stopped. By utilizing the structural characteristics of the heating device body 302, air in the high-pressure air release device 307 can be released through the high-pressure air nozzle 301, air pressure energy is instantly converted into air jet power energy, strong impact force can be generated, and the aims of cleaning ash, preventing nozzle blockage and cooling the spray gun fuel spray pipe are fulfilled.
The upper part of the first hearth kiln 1 is provided with a first distributing device 5, the upper part of the second hearth kiln 2 is provided with a second distributing device 6, and the first distributing device 5 and the second distributing device 6 are respectively connected with the receiving hopper 3 through an electro-hydraulic distributor 4. The double-hearth lime kiln also comprises a first flue gas regulating and controlling device 21 and a second flue gas device, wherein the first flue gas regulating and controlling device 21 is connected with the distributor through a first waste gas pipeline 17, is connected with the first hearth kiln 1 through a third waste gas pipeline 19 and is connected with the dust removing device through a first waste gas main channel 23; the second flue gas device is connected with the distributor through a second waste gas pipeline 18, connected with the second hearth kiln 2 through a fourth waste gas pipeline 20, and connected with the dust removal device through a second waste gas main channel 24.
The upper parts of the first hearth kiln 1 and the second hearth kiln 2 are respectively provided with a denitration agent input interface 30, a denitration agent for denitration in the furnace enters the first main heating spray gun 7 and the second main heating spray gun 8 from the denitration agent input interface 30 and is sprayed into the furnace by virtue of the internal channels of the spray guns, and the spraying amount of the denitration agent is controlled by a pipeline valve and a denitration agent preparation system metering device. The denitration agent injection is completed within the working time of the heat storage chamber, namely the injection of fuel is completed when the electric heating device of the injection gun is started when the first main heating injection gun 7 and the second main heating injection gun 8 stop injecting fuel, the temperature control of a working area during the injection of the denitration agent is completed by the electric heating device on the injection gun, the ideal temperature of the denitration working area is controlled within the range of 750 plus 950 ℃, and the electric heating device of the injection gun is not started when the temperature of the area reaches the ideal denitration temperature during the normal working of the heat storage chamber.
The bottom of the first hearth kiln 1 is provided with a first discharging device 13, and the bottom of the second hearth kiln 2 is provided with a second discharging device 14. A first cooling air pipeline 25 is arranged at the first discharging device 11, and a second cooling air pipeline 26 is arranged at the second discharging device 12. The lower part of the first discharging device 11 is provided with a first discharging device 13, and the lower part of the second discharging device 12 is provided with a second discharging device 14. The double-hearth lime kiln also comprises a discharge bin 15, and the outlets of the first discharge device 13 and the second discharge device 14 are connected with the discharge bin 15. The bottom of the discharging bin 15 is also provided with an ash discharging device 16 connected with the discharging bin 15.
The utility model discloses the method of utilizing the two thorax limekilns that are used for realizing that parallel flow is synchronous to be calcined against the current and denitration in the stove prepares quick lime, as follows:
a first cycle: the heat storage process from the calcination of the first hearth kiln 1 to the calcination of the second hearth kiln 2 comprises the following steps:
limestone raw materials are weighed by a receiving hopper 3 and then fed into an electro-hydraulic distributor 4 for distribution, the limestone raw materials after distribution enter a first distributor 5 through a closed chute, a double-layer closed distribution device is arranged in the first distributor 5, the distribution device is opened or closed through an electro-hydraulic lifting device in the device, the materials are uniformly distributed in a preheating zone of a kiln chamber A of a first kiln 1, the limestone raw materials fully exchange heat with waste gas waste heat rising in the kiln chamber in the preheating zone, when the temperature of waste gas reaching the top of the kiln exceeds 180 ℃, the waste gas enters a first distributor 55 for fully waste heat exchange again with the limestone raw materials, the waste gas with the temperature lower than 120 ℃ after exchange enters a first flue gas regulating and controlling device 21 through a first waste gas pipeline 17, and the regulated waste gas enters a first waste gas main channel 23 and leads to a dust removing device. When the temperature of the waste gas reaching the furnace top part is lower than 140 ℃, the waste gas directly enters a third waste gas pipeline 19, enters a first waste gas main channel 23 after being regulated by a first flue gas regulating and controlling device 21 and is led to a dust removal device.
When stones in the preheating zone in the first hearth 1A enter the calcining zone, the stones exchange heat with the hot flame sprayed by the first main heating spray gun 7, and the temperature of the calcining zone can reach the range of 1000-1200 ℃, so that the ideal limestone decomposition calcining temperature is reached. When part of decomposed limestone is converted into calcium oxide and slowly descends to the annular channel of the joint of the cooling zone and the calcining zone of the kiln chamber A of the first kiln 1, heat exchange is carried out between the limestone and cold air from the first cooling air pipeline 25, and the temperature of the cold air at the position can reach about 700 ℃ after heat exchange with the descending high-temperature lime. Since the calcining kiln 1 is always in the positive pressure state and is always kept in the range of 15-25Kpa, the pressure in the kiln chamber B of the second kiln 2 which is used as the heat storage kiln chamber in the same working period is smaller than that in the kiln chamber A, so that high-temperature waste gas at the annular channel enters the first annular gas channel 27, and the annular channel connecting port 28 of the first annular gas channel 27 flows to the second annular channel of the second kiln 2. A plurality of first auxiliary heating guns 9 and second auxiliary heating guns 10 are annularly and uniformly arranged in the first annular gas channel 27, the annular channel connecting port 28 and the second annular gas channel 29 to release heat energy for heat exchange again by high-temperature waste gas in the annular channel, the temperature of the high-temperature waste gas after heat exchange again can be increased to 900-plus-1000 ℃, so that the temperature of the waste gas flowing to the hearth B of the second hearth kiln 2 of the heat storage hearth reaches the lime decomposition temperature, the temperature of the waste gas is matched with the temperature of the smoke in the calcining zone of the second hearth kiln 2 of the heat storage hearth to reach the calcining temperature of the calcining zone, the waste gas rises from bottom to top through the outlet of the second annular gas channel 29, passes through the calcining zone of the hearth B to reach the preheating zone, the heat exchange is carried out with the second main heating spray gun 8 which releases heat at the same time, the spray gun nozzle of the hearth B is closed, and no solid fuel or gas and air enter, the released heat energy is generated by an electric heating device arranged on a second main heating spray gun 8, the heat release part is a combination part of a calcining zone and a preheating zone, the released heat energy smoke and high-temperature waste gas rising from bottom to top rise together to penetrate through the whole preheating zone to perform sufficient waste heat exchange with descending limestone, when the temperature of the waste gas reaches the top of the furnace and exceeds 180 ℃, the waste gas enters a second distributor 6 to perform sufficient waste heat exchange with limestone raw materials again, the waste gas with the temperature lower than 120 ℃ after the exchange is finished enters a second smoke regulating device 22 through a second waste gas pipeline 18, and the regulated waste gas enters a first waste gas main channel 23 to be led to a dust removal device. When the temperature of the waste gas reaching the furnace top part is lower than 140 ℃, the waste gas directly enters the fourth waste gas pipeline 20, enters the second waste gas main channel 24 after being regulated by the second flue gas regulation and control device 22 and is led to the dust removal device.
And a second circulation: and (3) a heat storage process from calcining of the kiln chamber B to calcining of the kiln chamber A:
limestone raw materials are weighed by a receiving hopper 3 and then fed into an electro-hydraulic distributor 4 for distribution, the stone materials after distribution enter a second hearth kiln 2 kiln B heat exchange closed second distributor 6 through a closed chute, a double-layer closed distributing device is arranged in the second distributor 6, the distributing device is opened or closed by an electro-hydraulic lifting device in the device to uniformly distribute the materials to a preheating zone in a second hearth kiln 2 kiln B, the limestone raw materials fully exchange heat with waste gas waste heat rising in the kiln in the preheating zone, when the temperature of the waste gas reaches the furnace top part exceeds 180 ℃, the waste gas enters the second distributor 6 for fully exchanging heat with the limestone raw materials again, the waste gas with the temperature lower than 120 ℃ after exchange enters a second flue gas regulating and controlling device 22 through a first waste gas pipeline 17, and the regulated waste gas enters a second waste gas main channel 24 and leads to a dust removal device. When the temperature of the waste gas reaching the furnace top part is lower than 140 ℃, the waste gas directly enters the fourth waste gas pipeline 20, enters the second waste gas main channel 24 after being regulated by the second flue gas regulation and control device 22 and is led to the dust removal device.
When stones in the preheating zone in the second hearth kiln 2 hearth B enter the calcining zone, the stones exchange heat with the glowing flame sprayed by the second main heating spray gun 8, and the temperature of the calcining zone can reach the range of 1000-. When the partially decomposed limestone is converted into calcium oxide and slowly descends to the second annular gas channel 29 at the joint of the cooling zone and the calcining zone in the kiln chamber B of the second chamber kiln 2, the limestone is subjected to heat exchange with cold air from the second cooling air pipeline 26, and the temperature of the cold air at the second annular gas channel can reach about 700 ℃ after the cold air is subjected to heat exchange with the descending high-temperature lime. The pressure in the kiln chamber A of the first kiln 1 converted into the heat storage kiln chamber in the same working period is smaller than that in the chamber B, so that the high-temperature waste gas at the position of the second annular gas channel 29 enters the first annular gas channel 27, and the annular channel connecting port 28 flows to the first annular gas channel 27. The second annular gas channel 29, the annular channel connecting port 28 and the first annular gas channel 27 are internally and uniformly provided with a plurality of second auxiliary heating spray guns 10 and first auxiliary heating spray guns 9 which are annularly and uniformly used for carrying out heat exchange again on high-temperature waste gas in the channels, the temperature of the high-temperature waste gas after heat exchange again can be increased to 900-plus-1000 ℃, so that the temperature of the waste gas flowing to the hearth A of the heat storage hearth reaches the lime decomposition temperature, the temperature of the waste gas is matched with the temperature of the flue gas in the calcining zone of the heat storage hearth A to meet the calcining temperature requirement of the calcining zone, the waste gas rises from bottom to top through the outlet of the first annular gas channel 27, the calcining zone passing through the first hearth reaches the preheating zone, the heat exchange is carried out with the first main heating spray gun 7 of the first hearth 1 which releases heat at the same time, the spray gun of the hearth A is closed at the moment, no solid fuel or gas and air enter, and the released heat energy is generated by the first electric heating device 205 arranged on the first main heating spray gun 7, the heat release part is a combination part of the calcining zone and the preheating zone, released heat energy smoke and high-temperature waste gas which rises from bottom to top rise to penetrate through the whole preheating zone and perform full waste heat exchange with descending limestone, when the temperature of the waste gas reaches the top part of the furnace and exceeds 180 ℃, the waste gas enters the first distributor 5 to perform full waste heat exchange with stone again, the waste gas with the temperature of less than 120 ℃ after the exchange is finished enters the first smoke regulation and control device 21 through the first waste gas pipeline 17, and the regulated waste gas enters the first waste gas main channel 23 to be led to the dust removal device. When the temperature of the waste gas reaching the furnace top part is lower than 140 ℃, the waste gas directly enters a third waste gas pipeline 19, enters a first waste gas main channel 23 after being regulated by a first flue gas regulating and controlling device 21 and is led to a dust removal device.
The utility model discloses a two kilns of 1 kiln thorax A of first thorax kiln and 2 kiln thorax B of second thorax kiln adopt per 15min or other settlement time switching-over to exchange and calcine, are in the malleation state all the time when kiln thorax A calcines, and the flue gas is from last down flowing, so-called "parallel flow" promptly. In the same time, the kiln chamber B is used as a heat storage chamber for heat storage, and the flue gas flows from bottom to top to complete the countercurrent heat storage function, so that the secondary synchronous calcination function is realized. The main fuel of the first main heating spray gun 7 can be injected by solid coal fuel or gas, the main fuel is injected by a dye spray pipe of the main heating spray gun, the auxiliary fuel is in an electric energy conversion heat energy mode and is realized by the first electric heating device 205 arranged outside the main heating spray gun and the auxiliary heating spray gun, and the ignition of the main heating spray gun and the auxiliary heating spray gun is realized by the electric energy conversion device on the spray gun device.
Although the invention has been described in detail with respect to the general description and the specific embodiments, it will be apparent to those skilled in the art that modifications and improvements can be made based on the invention. Therefore, such modifications and improvements are intended to be within the scope of the invention as claimed.
Claims (9)
1. A double-hearth lime kiln for realizing parallel-flow countercurrent synchronous calcination and denitration in a furnace is characterized in that,
the double-hearth lime kiln comprises a first hearth and a second hearth, a first annular gas channel is arranged at the bottom of the first hearth, a second annular gas channel is arranged at the bottom of the second hearth, and the first annular gas channel is communicated with the second annular gas channel;
the preheating zone at the upper part of the first hearth kiln is provided with a plurality of first main heating spray guns, and the preheating zone at the upper part of the second hearth kiln is provided with a plurality of second main heating spray guns;
a plurality of first auxiliary heating thermal guns are arranged in the first annular gas channel, and a second auxiliary heating thermal gun is arranged in the second annular gas channel;
the first main heating spray gun and the second main heating spray gun respectively comprise a spray gun fuel spray pipe, a first electric heating device, an inner heat insulation protective sleeve and an outer protective sleeve, wherein the inner heat insulation protective sleeve and the outer protective sleeve are arranged on the outer side of the spray gun fuel spray pipe, a cavity is formed between the inner heat insulation protective sleeve and the outer protective sleeve, and the first electric heating device is arranged in the cavity;
the first auxiliary heating spray gun and the second auxiliary heating spray gun respectively comprise a high-pressure air spray pipe, an inner side protective sleeve, an outer side protective sleeve, a second electric heating device and a high-pressure air releasing device;
the high-pressure air spraying pipe is characterized in that the inner side protective sleeve and the outer side protective sleeve are arranged on the outer side of the high-pressure air spraying pipe, a second electric heating device is arranged between the inner side protective sleeve and the outer side protective sleeve, and the high-pressure air releasing device is communicated with the high-pressure air spraying pipe.
2. The dual-chamber lime kiln for concurrent-current countercurrent synchronous calcination and denitration in furnaces as claimed in claim 1,
the first distributing device is arranged on the upper portion of the first hearth kiln, the second distributing device is arranged on the upper portion of the second hearth kiln, and the first distributing device and the second distributing device are connected with the receiving hopper through the electro-hydraulic distributor respectively.
3. The dual-chamber lime kiln for concurrent-current countercurrent synchronous calcination and denitration in furnaces as claimed in claim 2,
the double-hearth lime kiln further comprises a first flue gas regulating and controlling device and a second flue gas device, wherein the first flue gas regulating and controlling device is connected with the distributing device through a first waste gas pipeline, is connected with the first hearth lime kiln through a third waste gas pipeline, and is connected with the dust removing device through a first waste gas main channel;
the second flue gas device is connected with the distributing device through a second waste gas pipeline, connected with the second hearth kiln through a fourth waste gas pipeline and connected with the dust removal device through a second waste gas main channel.
4. The dual-chamber lime kiln for concurrent-current countercurrent synchronous calcination and denitration in furnaces as claimed in claim 1,
and the upper parts of the first hearth kiln and the second hearth kiln are respectively provided with a denitration agent input interface.
5. The dual-chamber lime kiln for concurrent-current countercurrent synchronous calcination and denitration in furnaces as claimed in claim 1,
the bottom of first thorax is equipped with first discharge device, the bottom of second thorax is equipped with second discharge device.
6. The dual-chamber lime kiln for concurrent-flow countercurrent synchronous calcination and denitration in furnaces as claimed in claim 5,
and a first cooling air pipeline is arranged at the first discharging device, and a second cooling air pipeline is arranged at the second discharging device.
7. The dual-chamber lime kiln for concurrent-flow countercurrent synchronous calcination and denitration in furnaces as claimed in claim 5,
and a first discharging device is arranged at the lower part of the first discharging device, and a second discharging device is arranged at the lower part of the second discharging device.
8. The dual-chamber lime kiln for concurrent-current countercurrent synchronous calcination and denitration in furnaces as claimed in claim 7,
the double-hearth lime kiln further comprises a discharge bin, and outlets of the first discharge device and the second discharge device are connected with the discharge bin.
9. The dual-chamber lime kiln for concurrent-current countercurrent synchronous calcination and denitration in furnaces as claimed in claim 8,
the bottom of the discharging bin is also provided with a dust discharging device connected with the discharging bin.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113480202A (en) * | 2021-07-23 | 2021-10-08 | 唐山市丰南区金泉冶金能源新技术开发有限公司 | Double-hearth lime kiln and method for realizing parallel-flow countercurrent synchronous calcination and denitration in kiln |
| CN114538801A (en) * | 2022-04-07 | 2022-05-27 | 广西大学 | Biofuel shaft kiln for firing calcium oxide and method for firing calcium oxide |
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2021
- 2021-07-23 CN CN202121694962.3U patent/CN215102889U/en active Active
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113480202A (en) * | 2021-07-23 | 2021-10-08 | 唐山市丰南区金泉冶金能源新技术开发有限公司 | Double-hearth lime kiln and method for realizing parallel-flow countercurrent synchronous calcination and denitration in kiln |
| CN113480202B (en) * | 2021-07-23 | 2024-02-27 | 唐山市丰南区金泉冶金能源新技术开发有限公司 | Double-chamber lime kiln and method for realizing concurrent and countercurrent synchronous calcination and in-furnace denitration |
| CN114538801A (en) * | 2022-04-07 | 2022-05-27 | 广西大学 | Biofuel shaft kiln for firing calcium oxide and method for firing calcium oxide |
| CN114538801B (en) * | 2022-04-07 | 2023-02-17 | 广西大学 | Biofuel shaft kiln for firing calcium oxide and method for firing calcium oxide |
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