CN218879751U

CN218879751U - Central burner type lime kiln

Info

Publication number: CN218879751U
Application number: CN202320170978.7U
Authority: CN
Inventors: 刘玉泉; 刘久盛
Original assignee: Tangshan Jinquan Metallurgical Technology Industry Co ltd
Current assignee: Tangshan Jinquan Metallurgical Technology Industry Co ltd
Priority date: 2023-02-09
Filing date: 2023-02-09
Publication date: 2023-04-18
Anticipated expiration: 2033-02-09

Abstract

The utility model discloses a center nozzle formula limekiln, including shaft furnace body, the interior center nozzle combustor of stove, subtend double helix dosing device, porous formula air distributor and honeycomb formula waste heat fuel drying device, the burning zone of shaft furnace body is equipped with outer peripheral combustion chamber of stove, the interior center nozzle combustor of stove sets up on the axis in the shaft furnace body and lie in the below of outer peripheral combustion chamber of stove, subtend double helix dosing device is connected with porous formula air distributor process, and through the novel combination of key devices such as the interior center nozzle combustor of stove and outer peripheral combustion chamber of stove, honeycomb formula waste heat fuel drying device, high temperature heat storage device, the key technological problem of combustion-supporting air and the rare looks mixed synchronous transport of living beings powder and burning and living beings powder spontaneous combustion ignition has been solved.

Description

Central burner type lime kiln

Technical Field

The utility model relates to a lime production technical field, concretely relates to center nozzle formula limekiln.

Background

With the ecological environment protection entering a new stage of pollution and carbon reduction cooperative treatment, lime kilns adopting solid traditional fossil energy fuels such as coal and the like are gradually eliminated or strictly prohibited to be constructed, and a lime production link is also listed as a key field needing ultra-low emission modification. Under the aims of carbon peak reaching and carbon neutralization, the lime industry develops replaceable novel energy sources to reduce the consumption of primary fossil fuel while improving the production technology, and the method is a necessary way for realizing the low-carbon development of the lime industry.

Among various alternative renewable energy sources, nuclear energy and large-scale hydropower have potential ecological environment risks, and regional resource constraints such as wind energy and geothermal heat are restricted and questioned in vigorous development, while biomass energy is accepted by people due to the characteristics of universality, richness, reproducibility and the like. The uniqueness of biomass lies in that the biomass can store solar energy and also can be converted into conventional solid, liquid and gaseous fuels by using a renewable carbon source, and energy sources such as coal, petroleum, natural gas and the like are substantially converted from biomass energy. Moreover, biomass energy is taken as a clean renewable energy source, and has the characteristics of wide source, environmental friendliness, carbon neutrality and the like, and is listed as the fourth big energy source. It is predicted that by the middle of the 21 st century, various biomass alternative fuels produced using new technologies will account for over 40% of the total global energy consumption.

The natural biomass energy has high volatile component content and is easy to burn, the physical and chemical properties of the pyrolyzed biochar are close to those of pulverized coal, and the biomass energy is used as fuel for lime production, so that the energy-saving and emission-reducing effects of the biochar can be effectively exerted. The calculation is carried out seriously, the yield of the lime shaft kiln which produces 10 ten thousand tons per year is calculated, if biomass fuel is adopted to replace fire coal, 1 ten thousand tons of carbon emission can be reduced every year, 3.6 ten thousand tons of carbon dioxide emission can be reduced, and the potential of emission reduction and energy conservation is huge.

Modern utilization of biomass energy can be divided into four basic types: direct combustion, pyrolysis, gasification and liquefaction.

Direct combustion is the simplest way in which biomass is applied and is also the traditional way used for the earliest time, but part of biomass is used as low-grade fuel, the combustion efficiency is extremely low, and the temperature reached by combustion is low, so that the industrial application of biomass energy is greatly influenced.

Pyrolysis is a basic thermochemical process that converts biomass into useful fuels. Biomass is combusted in the absence of oxygen heating or in the presence of a portion of the oxygen, and can produce a hydrocarbon-rich gas mixture, an oily liquid, and a carbon-rich solid residue. The pyrolysis has the advantages of simple equipment and capability of producing carbon and various chemical products; the defects are low utilization rate and small applicability.

Gasification is also a pyrolysis technology, mainly a technology for converting substances into combustible gas, and can be low-calorific value gas or medium-calorific value gas according to different technical routes. The biomass gasification furnace has the main advantages that after the biomass is converted into combustible gas, the utilization efficiency is higher, and the biomass gasification furnace is wide in application, for example, the biomass gasification furnace can be used as domestic gas, and can also be used for gas utilization of a boiler or direct power generation; the main drawback is the complexity of the system and the inconvenience of storage and transport of the gas produced, necessitating either a dedicated user or a dedicated utility.

In the liquefaction process, under the action of a proper catalyst, raw material macromolecules are decomposed into small molecular compounds, and the small molecular compounds are polymerized into oil compounds with a proper molecular weight. The main advantage of liquefaction is that biomass can be made into oil products for combustion, and the biomass can be used as a substitute of petroleum, so that the application range and the additional value are greatly improved; the main disadvantage is the complex technology and the high cost.

Practice and research show that the biomass gasification and liquefaction technology has complex process and large investment, and although clean and efficient secondary fuel can be obtained, the yield is not high, the economy is not reasonable enough, and industrialization and further popularization are difficult in the near future. Direct combustion is the simplest and earliest biomass energy utilization method, but in the traditional combustion method in the past, the biomass combustion efficiency is extremely low, and the waste of energy and resources is great. Therefore, if a convenient and efficient biomass direct combustion technology can be researched and developed, the method has good economic and social benefits.

At present, the lime production mode is mainly a shaft kiln process, and a single fuel structure mode is adopted for production no matter in a single-chamber shaft kiln and a double-chamber shaft kiln: firstly, a mixing type production process of mixing and burning lump coal fuel and stone is adopted, and secondly, fluid fuels such as fuel gas, fuel oil and the like are adopted for production. Although the industry has tried to adopt a production mode of directly mixing and burning solid fuel such as biomass particles or briquettes and stones, the biomass fuel has the defects of low calorific value, high volatile components, high ash content, short burning time and the like, so that the biomass fuel cannot be used in a conventional shaft kiln. Particularly, the heat value of the biomass is only about 4000 kilocalories, the direct combustion cannot reach the decomposition temperature of lime production, the volatile component is more than 70 percent, and the biomass cannot reach the calcining zone of the lime shaft kiln in the production of the shaft kiln and is discharged out of the kiln along with flue gas, so that the heat loss is large, and the decomposition temperature of the lime production cannot be reached.

SUMMERY OF THE UTILITY MODEL

Therefore, the utility model provides a central nozzle formula limekiln uses through the combination of key devices such as neotype interior central nozzle combustor and peripheral combustion chamber outside the stove, honeycomb formula waste heat fuel drying device, high temperature heat accumulation device, has solved combustion-supporting air and living beings powder rare phase and has mixed synchronous transport and burning and living beings powder spontaneous combustion ignition's key technological problem to solve the corresponding technical problem who mentions in the background art.

The utility model discloses break through traditional living beings utilization mode, propose to make the powder with living beings and utilize, acquire enough energy, but to the sustainable use of the energy and environmental protection important meaning.

The utility model discloses from the production methods of biomass fuel in to active lime production, technological parameter, deep research such as physical mechanism and chemical kinetics, found to make living beings powder pyrolysis calcine lime for pyrolysis gas and pyrolysis carbon black direct combustion in lime shaft kiln and main points such as production process control, untied shaft kiln from a brand-new production technology and theory and adopted living beings solid powder fuel to calcine active lime's commonality problem, especially realized directly setting up the purpose of central nozzle jetting solid biomass powder fuel production active lime in the stove, still realized "gas powder dual combustion" and "oxyhydrogen combustion method" production lime simultaneously. The production process and the production device of the active lime have the advantages of realizing the typical characteristics of direct biomass combustion and thermal cracking coupling combustion, along with short calcination time, low energy consumption, high activity of the produced lime and low contents of C and S elements.

The utility model discloses can promote the transformation regeneration of the fuel selection of production lime, to realizing the green of lime industry, falling carbon upgrading, solve trade commonality bottleneck, have the key meaning.

The utility model discloses a combination of subtend double helix dosing device, the porous formula air distributor of fuel dilute phase, stove center nozzle blowout ware, peripheral combustion chamber outside the stove, honeycomb formula waste heat fuel drying device, high temperature heat accumulation device etc. is used, has not only reached the purpose of independent direct jetting living beings powder production high activity lime, still has the function that makes combustion-supporting air and living beings powder dilute phase mix synchronous transport, has solved the key technological problem that living beings powder spontaneous combustion was igniteed.

The utility model discloses still have the function of low heat value gas fuel production such as independent use blast furnace gas and producer gas, can allocate the switching by oneself according to the production operating mode, adopt full automatization DCS control freely to allocate, can reach technological characteristic requirements such as the firing temperature of ideal, the concentration limit that catches fire, flame propagation speed, combustion reaction speed. The technology has the advantages of simple, practical and compact structure, high production efficiency, high yield and good economical efficiency. The method has the advantages of deep utilization of biomass fuel, reduction of serious pollution to the environment caused by the use of fossil fuel, improvement of the overall lime production process level, reduction of production cost, improvement of product quality, pollution and carbon reduction, improvement of ecological environment, guarantee of energy safety and the like.

Adopting one or more key process measures as follows:

(1) And the waste heat exchange function of the burner of the central burner in the furnace and the high-strength heat storage device in the preheating zone in the furnace is utilized to fully heat the combustion-supporting air, so that the combustion-supporting air achieves the function of self-ignition and ignition combustion of the biomass powder.

(2) And blowing biomass powder into the lime shaft furnace to crack the biomass powder into pyrolysis gas and pyrolysis carbon black. Pyrolysis gas is mainly H ₂ CO, the pyrolyzed carbon black reacts with oxygen in a calcining zone of the lime shaft furnace to generate carbon monoxide and participate in combustion,the unit calorific value and the combustion temperature of biomass powder can be effectively improved by controlling the blowing amount of the biomass powder, and when the blowing amount of the biomass powder is higher, the biomass powder can also react with carbon dioxide to generate carbon monoxide.

(3) The technology of coupling combustion of the biomass powder and the hydrogen-rich gas is adopted, the biomass powder contains 10-30% of moisture, and when water vapor is in an environment with the temperature of more than 1200 ℃ in the combustion process, the water vapor is decomposed into hydrogen and oxygen to participate in combustion, so that the hydrogen is fully combusted to release more heat, the aim of combustion heat generation by taking part of water as fuel is achieved, and the aims of supporting combustion and improving the combustion temperature are also achieved,

(4) And pyrolysis gas H generated when biomass powder is combusted in a high-temperature zone in the furnace ₂ The content can reach more than 14 percent, the content of CO can reach more than 20 percent, and CH ₄ The content can reach more than 5 percent, and the combustible gases are all converted into heat energy in the combustion process, thereby improving the combustion temperature and reaching the decomposition temperature of limestone.

Adopting one or more of the following key equipment and measures:

(1) The combined application of the solid biomass powder fuel opposite direction double-screw quantitative feeding device, the combustion-supporting fan (high-pressure fan), the porous air distributor and the conveying pipeline realizes the conveying of pressure and pneumatic dilute-phase materials required by the conveying of the biomass powder, and achieves the purpose of synchronous conveying and burning of the combustion-supporting air and the biomass fuel.

(2) The biomass powder is partially dehydrated by a gas phase pressure swing flash evaporation process principle to prepare the biomass hydrogen-rich micro powder with high heat value and high oxygen content, and simultaneously, the biomass hydrogen-rich micro powder achieves ideal conveying performance and an ideal ignition point.

(3) And carrying out dilute phase conveying on the preheated and dried biomass powder, and independently butting an independent branch pipeline arranged at an outlet of the porous air distributor with a peripheral burner outside the lime shaft furnace body arranged in a roasting system of the lime shaft furnace so as to realize that each independent burner has an independent fuel conveying pipeline.

(4) And a burner with a burner at the center in the lime shaft furnace is arranged in the furnace body of the lime shaft furnace, biomass powder fuel is blown to the central part in the furnace, and when flame of the burner at the periphery outside the furnace cannot reach the central part of the furnace body, heat energy supplement is effectively carried out on the part (the biomass powder is combusted to provide heat energy).

(5) And a combustion-supporting air preheating function is arranged in the central burner in the furnace, so that the combustion-supporting air of the central burner in the furnace and the combustion-supporting air of the peripheral burners outside the furnace are preheated, and the aims of saving energy and improving the combustion efficiency are fulfilled.

(6) And the biomass powder fuel is blown into the furnace by using the central burner in the furnace, so that the aim of directly burning the biomass powder is fulfilled.

(7) And a plurality of high-temperature heat storage devices are arranged in the furnace body preheating zone, and the high-temperature waste gas temperature of the furnace body preheating zone is utilized to carry out secondary high-temperature heat storage on the primarily preheated combustion-supporting air from the furnace center burner, so that the temperature of the combustion-supporting air is raised to be more than 350 ℃, the biomass powder ignition point is reached, and the self-ignition combustion is realized.

(8) The multifunctional lifting type rotary distributor is arranged in a distribution system of a furnace body of the lime shaft furnace, stone with different particle sizes in the stone is distributed in a grading manner through the lifting, tilting, rotating and other functions of the device, the stone with large particle sizes is uniformly distributed on the periphery of the kiln wall, and the combustion penetration resistance of flame of a burner on the periphery outside the furnace is reduced.

(9) The ash discharge system is provided with a multi-point rotary metering ash discharge device (a movable material flow control device, a liftable material flow control device, a unidirectional rotary ash discharge device and a two-stage sealing discharger), and the furnace condition can be controlled and adjusted by accurately controlling the ash discharge amount.

(10) And a high-pressure combustion-supporting cooling type multifunctional blast cap is arranged in an air supply system of the lime shaft furnace body, so that the purposes of supporting combustion air and cooling a combustion device in the central furnace are achieved.

In order to achieve the above object, the present invention provides the following technical solutions:

a central burner type lime kiln comprises a shaft furnace body, a central burner in the shaft furnace body, an opposite double-helix quantitative feeding device, a porous air distributor and a honeycomb type waste heat fuel drying device, wherein a combustion zone of the shaft furnace body is provided with a peripheral combustion chamber outside the shaft furnace, the central burner in the shaft furnace body is arranged on an axis in the shaft furnace body and is positioned below the peripheral combustion chamber outside the shaft furnace, the opposite double-helix quantitative feeding device is connected with the porous air distributor in a working procedure, the porous air distributor is connected with a material inlet of the honeycomb type waste heat fuel drying device, a smoke inlet of the honeycomb type waste heat fuel drying device is connected with the top of the shaft furnace body through a pipeline, and a material outlet of the honeycomb type waste heat fuel drying device is connected with the peripheral combustion chamber outside the shaft furnace and the central burner in the shaft furnace.

Furthermore, the honeycomb type waste heat fuel drying device is a honeycomb type multi-section drying device and comprises an inner furnace feeding section and an outer furnace feeding section, wherein multi-pipe type channels are arranged in the inner furnace feeding section and the outer furnace feeding section, the porous air distributor is connected with material inlets of the inner furnace feeding section and the outer furnace feeding section through two pipelines, material outlets of the inner furnace feeding section are connected with the multilayer blowing chambers of the inner furnace central burner in a one-to-one correspondence mode through a plurality of independent pipelines, and material outlets of the outer furnace feeding section are connected with the combustion chambers on the periphery of the outer furnace in a one-to-one correspondence mode through a plurality of independent pipelines.

Furthermore, the honeycomb type waste heat fuel drying device also comprises a plurality of sections of combustion-supporting gas heating sections, wherein the plurality of sections of combustion-supporting gas heating sections are connected in series; the lime kiln further comprises a first combustion-supporting fan, the first combustion-supporting fan is connected with the porous air distributor through a pipeline, the first combustion-supporting fan is connected with an air inlet at the head of the section of the combustion-supporting gas heating section in series connection through another pipeline, and a combustion-supporting gas outlet at the tail of the section of the combustion-supporting gas heating section in series connection is connected with the combustion chamber around the outside of the lime kiln through a pipeline.

Further, the furnace outer periphery combustion chamber comprises at least one furnace outer periphery short flame combustion chamber and at least one furnace outer periphery flat long flame combustion chamber, and the furnace outer periphery short flame combustion chamber is positioned above the furnace outer periphery flat long flame combustion chamber.

Furthermore, the furnace outer periphery combustion chamber also comprises a furnace outer periphery inclined long flame combustion chamber, the furnace outer periphery inclined long flame combustion chamber is positioned below the furnace outer periphery flat long flame combustion chamber, the furnace outer periphery inclined long flame combustion chamber is positioned above the furnace inner center burner combustor, and the furnace outer periphery inclined long flame combustion chamber can spray inclined downward combustion-supporting gas towards the furnace inner center burner combustor.

Furthermore, the lime kiln further comprises a second combustion-supporting fan, a high-temperature heat storage device and an external hot air surrounding pipe, wherein a cooling channel is arranged in the furnace center burner, the second combustion-supporting fan is connected with the cooling channel in the furnace center burner through a pipeline, the high-temperature heat storage device is arranged at the top of the shaft furnace body, an outlet of the cooling channel in the furnace center burner is connected with the high-temperature heat storage device through a pipeline, the high-temperature heat storage device is connected with the external hot air surrounding pipe through a descending pipeline, and a material outlet of an external feeding section of the honeycomb type waste heat fuel drying device is connected with the external peripheral combustion chamber through a corresponding pipeline and the external hot air surrounding pipe.

Furthermore, the lime kiln also comprises a combustion-supporting air hood, wherein the combustion-supporting air hood is arranged at the center of the bottom of the shaft furnace body, and the shaft furnace body is positioned below the central burner in the furnace.

Furthermore, the lime kiln further comprises a stone weighing device, a feeding trolley and a lifting type rotary distributor which are sequentially connected in the process, wherein the stone weighing device and the feeding trolley are arranged outside the shaft furnace body, and the lifting type rotary distributor is arranged at the top of the shaft furnace body.

Further, lime kiln still includes peripheral discharge bin, peripheral unloading pipe, movable material stream controlling means, central discharge bin, liftable formula material stream controlling means, unidirectional rotation ash discharging device, metering device, discharge controller, ash discharging bin and the sealed row of material ware of two-stage, peripheral discharge bin and central discharge bin set up the bottom of shaft furnace body, peripheral discharge bin is in the week side evenly distributed of central discharge bin, unidirectional rotation ash discharging device sets up the below of central discharge bin, peripheral discharge bin passes through peripheral unloading pipe with unidirectional rotation ash discharging device connects, and movable material stream controlling means sets up in the peripheral unloading pipe, the bottom of central discharge bin is equipped with liftable formula material stream controlling means, unidirectional rotation ash discharging device with metering device connects, metering device with ash discharging bin, metering device is equipped with the discharge controller, ash discharging bin with the sealed row of two-stage material ware connects.

The utility model has the advantages of one or more of the following:

(1) And the fuel such as coal, coal gas, natural gas and the like is replaced by the wood, the wood chips and the straws to calcine the lime, so that the fuel cost is reduced, and the environment is protected.

(2) The biomass powder is conveyed by only one opposite double-helix quantitative feeding device, and the feeding and switching of the fuel can be completed under the condition of hardly increasing the cost.

(3) The problem of uneven heat supply of biomass powder due to physical characteristics can be reduced to the maximum extent, and each burner and each combustion chamber can obtain corresponding fuel quantity.

(4) The ideal combustion effect is realized by controlling key process nodes such as the particle size of biomass powder, the powder flow rate, the primary air intake, the secondary air intake, the optimal concentration of the powder in the air and the like.

(5) The fuel gas can be independently and completely used for production; or the biomass powder fuel is used for production independently and completely; or can realize the mixed combustion production of fuel gas and biomass powder fuel.

(6) The central burner in the furnace is arranged, so that the central heat energy in the furnace is supplied more uniformly, the problems of low yield and high lime burning rate caused by the fact that the heat energy cannot reach the center of the furnace in the traditional peripheral burner type gas shaft kiln are solved, the yield of the traditional single-hearth shaft kiln is increased by times, and the yield and the production utilization coefficient are higher than those of the traditional double-hearth lime kiln.

(7) The system has simple and compact structure and is convenient to operate.

(8) The main technological structure characteristics of traditional coal-fired lime shaft furnace and gas lime shaft furnace do not change, make most lime shaft furnaces all can use the technical scheme of the utility model, do benefit to the industrialization and promote.

(9) And realizing carbon dioxide emission reduction: the main component of the biomass fuel is carbohydrate, carbon dioxide emitted in the combustion process is equivalent to carbon dioxide absorbed in photosynthesis, and a natural carbon balance is formed, and scientifically, the carbon balance is called zero emission.

(10) And sulfur dioxide emission is low: the biomass fuel has low sulfur content, the emission of sulfur dioxide is less than 1mg/m < 3 >, the emission is far lower than the emission of carbon dioxide generated by burning coal and fuel oil, and the emission reduction of sulfur dioxide can be realized without installing a desulfurization device.

(11) The biomass fuel has rich resources and can be regenerated and cyclically grown, which is inexhaustible.

(12) The investment is low, and the characteristics of high investment return rate and investment cost ratio of the traditional lime shaft furnace are continued; compared with the investment of the traditional single-chamber mixing type coal-fired lime shaft furnace, the investment of the whole production system is not increased except the increased investment of combustion system devices; compared with the investment of the double-chamber lime kiln, the investment is about one third of that of the double-chamber lime kiln under the same yield.

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 range 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 central burner type lime kiln provided by an embodiment of the present invention.

In the figure: 1: a counter double-helix quantitative feeding device; 2: a porous air distributor; 3: a honeycomb type waste heat fuel drying device; 3-1: a furnace feed section; 3-2: a furnace external feeding section; 4: a branch feed conduit; 5: a first combustion fan; 6: an external hot air surrounding pipe; 7: a furnace central burner; 8: a shaft furnace body; 9: a stone weighing device; 10: a feeding trolley; 11: a lifting rotary distributor; 12: a short flame combustion chamber around the outside of the furnace; 13-1: a long flame combustion chamber with a horizontal periphery outside the furnace; 13-2: the periphery outside the furnace is provided with an oblique long flame combustion chamber; 14: a combustion-supporting blast cap; 15: a peripheral discharge bin; 16: a peripheral blanking pipe; 17: a movable material flow control device; 18: a central discharge bin; 19: a liftable material flow control device; 20: a unidirectional rotation ash discharging device; 21: a metering device; 22: a discharge controller; 23: an ash discharge bin; 24: a two-stage sealing discharger; 25: a second combustion fan; 26: a high temperature thermal storage device; 27: a furnace bottom hot air surrounding pipe; 28: a first combustion air duct; 29: a second combustion supporting air duct.

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.

In the present specification, the terms "upper", "lower", "left", "right", "middle", and the like are used for the sake of clarity only, and are not intended to limit the scope of the present invention, and changes or adjustments of the relative relationship thereof are also considered to be the scope of the present invention without substantial changes in the technical content.

As shown in FIG. 1, the present embodiment provides a central-burner lime kiln, which realizes dilute-phase transportation of biomass powder fuel by combining with a porous air distributor 2 by providing precise feeding of biomass powder to a double-helix dosing device 1. In the conveying process, the honeycomb type waste heat fuel drying device 3 exchanges heat with high-temperature flue gas with the temperature of more than 500 ℃ from the furnace top, and biomass powder is partially dehydrated and dried by a gas phase pressure swing flash evaporation process principle to form biomass hydrogen-rich micro powder with high heat value and rich oxygen, and simultaneously, the moisture in the conveyed fuel reaches a proper combustion proportion.

The honeycomb type waste heat fuel drying device 3 is internally designed into a tubular honeycomb structure, is butted with a plurality of pipelines (a single pipe is butted with a single pipe) which are equal to the porous air distributor 2, supplies biomass powder to an external furnace peripheral combustor (an external furnace peripheral short flame combustion chamber 12, an external furnace peripheral flat long flame combustion chamber 13-1 and an external furnace peripheral inclined long flame combustion chamber 13-2) arranged outside a furnace body and an internal furnace central combustor 7 arranged inside the furnace body respectively through a plurality of independent conveying branch pipelines arranged on the porous air distributor 2, simultaneously communicates with combustion-supporting fans (a first combustion-supporting fan 5 and a second combustion-supporting fan 25) through pipelines, and realizes high-pressure oxygen-enriched combustion of the biomass powder in a calcining zone area inside the lime shaft furnace by controlling flow control devices, pressure control devices, valves and the like arranged on corresponding pipelines.

The stones are uniformly distributed in a preheating zone in the furnace after passing through a stone weighing device 9, a feeding trolley 10 and a lifting rotary distributor 11 at the top of the furnace in sequence. When the stone material in the preheating zone slowly falls to the upper part of the calcining zone in the furnace, the stone material firstly exchanges heat with the flame sprayed from the short flame combustion chamber 12 at the periphery outside the furnace, so that the stone material reaches the initial decomposition temperature of more than 890 ℃. When the initially decomposed stone material slowly descends to the middle of the calcining zone in the furnace, heat exchange is performed again with the flame sprayed out from the outer periphery of the furnace to the long flame combustion chamber 13-1, so that the stone material reaches a temperature of 1100 ℃ or higher at which the stone material can be completely decomposed, carbon dioxide in the limestone in this region can be sufficiently decomposed and released, and about 70% or more of the limestone is decomposed into calcium oxide (lime). Because of the short combustion characteristic of the biomass powder fuel flame and the resistance of stone materials in the furnace, the flame of the combustion chamber at the periphery outside the furnace can not penetrate through the central area in the furnace body, about 30 percent of limestone in the central part in the furnace can not be completely decomposed, and slowly descends to the lower part of a calcining zone in the furnace together with other decomposed calcium oxide, and is combusted again with the fuel sprayed by the central burner 7 in the furnace for heat exchange, so that the limestone in the furnace can be completely decomposed. The calcium oxide generated after complete decomposition gradually descends to a cooling zone inside the furnace body.

The central burner 7 has a heat exchange function, and can exchange waste heat of cooling air and high-temperature calcium oxide while cooling the burner, so that the temperature of the combustion air is increased for the first time, the heated combustion air and high-temperature flue gas in a preheating zone of the furnace top at the temperature of 450-550 ℃ are subjected to secondary high-temperature heat storage, the temperature is increased, and the ideal biomass powder ignition temperature is reached through the high-temperature heat storage device 26. The high-temperature combustion-supporting air is communicated with a combustion chamber at the periphery outside the furnace through a pipeline and a hot blast surrounding pipe 6 outside the furnace, and is mixed and combusted with the biomass powder dried by the honeycomb type waste heat fuel drying device 3. The ignition point of the biomass powder is only 300-350 ℃, and the biomass powder is self-ignited and combusted after meeting high-temperature combustion air at 350-450 ℃ to form stable combustion flame.

In the whole calcining process, the secondary combustion-supporting air (cold air) blown out from the combustion-supporting air hood 14 of the cooling zone in the furnace and the high-temperature hot calcium oxide with the temperature of 750-950 ℃ falling from the cooling zone perform heat exchange in a countercurrent mode, and the exchanged high-temperature air with the same temperature continuously flows upwards to the calcining zone in the furnace to participate in calcining, so that the temperature of the calcining zone is stabilized at the optimal limestone decomposition temperature of 1250 ℃.

When the completely decomposed and cooled calcium oxide slowly falls to the lower area of the combustion-supporting air blast cap 14 device in the furnace, the temperature of the calcium oxide is reduced to about 200 ℃, and the purposes of calcium oxide cooling and heat exchange are achieved. The cooled calcium oxide enters a plurality of peripheral discharging bins 15 which are equally distributed according to the periphery of the kiln wall and a central discharging bin 18 which is arranged at the center of the furnace, and is controlled by a movable material flow control device 17 and a lifting material flow control device 19 to descend to the upper surface of a one-way rotary ash discharging device 20 through a peripheral discharging pipe 16 and a central discharging pipe 17, the calcium oxide is discharged into a plurality of metering devices 21 through rotation, the metered calcium oxide is discharged into an ash discharging bin 23 at the bottom of the furnace through a discharging controller 22, and the materials are discharged out of the furnace through a two-stage sealing discharger 24.

The main process flow is as follows:

the powder is fed to a perforated air distributor 2 by means of a double-helix dosing device 1, the perforated air distributor 2 being connected to a branch feed line 4. The first combustion air fan 5 feeds combustion air into the porous air distributor 2 through a first combustion air duct 28. The porous air distributor 2 distributes the combustion-supporting air uniformly and evenly, so that the combustion-supporting air is combined with the powder supplied to the double-helix quantitative feeding device 1 to form dilute phase conveying. The dilute phase material enters the honeycomb type waste heat fuel drying device 3 to be preheated and dried with the flue gas from the furnace top. The honeycomb type waste heat fuel drying device 3 is set to be in a multi-section type, wherein an inlet of a material supply section 3-1 in the furnace is a multi-tube type channel, and dilute phase materials from a material supply branch pipeline 4 are subjected to multi-channel flow distribution, so that the material amount in each pipeline is equal. The outlet of the feeding section 3-1 in the furnace of the honeycomb type waste heat fuel drying device 3 is equal to the inlet of the pipeline in number, and the outlet of each pipeline is connected with an independent pipeline to form an independent conveying channel which is respectively communicated with a plurality of channels in the independent external bottom hot blast surrounding pipe 27 of the lime shaft furnace body. The number of the burners connected with the furnace bottom hot blast surrounding pipe 27 is equal to that of the outlet pipelines of the feeding section 3-1 in the furnace. The outlet of each pipeline is connected with an independent pipeline to form an independent conveying channel which is respectively communicated with the multi-layer nozzles of the furnace center burner 7 of the shaft furnace body 8. And a plurality of layers of injection chambers are arranged in the central burner 7, and each injection chamber is respectively connected with a plurality of independent conveying pipelines from the outlet of the feeding section 3-1 in the furnace to form an independent conveying and injection unit.

The inlet of the external furnace material supply section 3-2 of the honeycomb type waste heat fuel drying device 3 is also a multi-pipe type channel, and dilute phase materials from the pipelines of the material supply branch pipeline 4 are subjected to multi-channel flow distribution, so that the material quantity in each pipeline is equal. The outlet of the external feeding section 3-2 of the honeycomb type waste heat fuel drying device 3 is equal to the number of the inlet pipelines, the outlet of each pipeline is connected with an independent pipeline to form an independent conveying channel, the independent conveying channel is communicated with the short flame combustion chamber 12 at the periphery of the furnace, the long flame combustion chamber 13-1 at the periphery of the furnace and the long flame combustion chamber 13-2 at the periphery of the furnace of the shaft furnace 8, and each independent combustion chamber at the periphery of the furnace is respectively connected with the outlet of the external feeding section 3-2 through the independent conveying pipeline to form an independent conveying and blowing unit.

The ends of the branch feed pipes 4 are divided into at least two and are connected to the inlets of the feed sections 3-1 inside the furnace and 3-2 outside the furnace, or the branch feed pipes 4 are divided into two different diameters and are connected to the outlets of the porous air distributors 2, so that the amount of powder material entering the feed sections 3-1 inside the furnace and 3-1 inside the furnace can be controlled. Because the honeycomb type waste heat fuel drying device 3 is in a multi-section type, the feeding section 3-1 in the furnace and the feeding section 3-2 outside the furnace are only one section of the honeycomb type waste heat fuel drying device 3, and the rest section is used for heating combustion air.

The whole production system of the shaft furnace is completed by a shaft furnace body 8 of the shaft furnace, stone materials enter a feeding trolley 10 through a weighing device 9 and are lifted into a furnace top lifting type rotary distributor 11, when the stone materials enter the furnace body 8, the stone materials are firstly preheated with smoke gas at the temperature of about 450-550 ℃ in a preheating zone in the furnace, when the preheated stone materials reach above 600 ℃, the stone materials slowly descend to a calcining zone, the calcining zone of the furnace body 8 in the middle of the furnace body is provided with three layers or multiple layers of combustion chambers, wherein a short flame combustion chamber 12 at the outer periphery of the furnace at the uppermost layer and a long flame combustion chamber 13-1 at the outer periphery of the furnace at the middle layer jointly emit incandescent flames, and the stable high-temperature zone is formed in the zone and exchanges heat with the stone materials. When the limestone is decomposed to about 70 percent, the limestone slowly descends to the upper part of a furnace central burner 7, powder dilute phase fuel sprayed by a plurality of layers of nozzles of the furnace central burner 7 and flame sprayed by a furnace outer peripheral oblique long flame combustion chamber 13-2 at the lowest layer of a calcining zone form a cross flame combustion area, a combustion layer with an integral section is formed in the furnace, and the decomposition of the residual stone material of about 30 percent is completed. The secondary combustion air of the whole calcining zone comes from a combustion air cap 14 and a second combustion air blower 25 which are arranged at the bottom of the furnace.

A cooling channel is arranged in the central nozzle burner 7, an air cooling mode is adopted, cooling air comes from a second combustion fan 25, the temperature of the cooling air after passing through the interior of the central nozzle burner 7 reaches about 100 ℃, the cooling air rises to a high-temperature heat storage device 26 arranged on the top of the furnace (the heat exchange pipe of the high-temperature heat storage device is positioned in the furnace) through a pipeline, and the high-temperature heat storage (heat exchange) is carried out on the cooling air and the flue gas in the range of 450-550 ℃ at the top of a preheating zone in the furnace, the temperature is raised to about 400 ℃, and the high-temperature combustion-supporting air is dropped into an external hot air surrounding pipe 6 outside a calcining zone of the furnace body through a plurality of descending pipes in different directions, the external hot air surrounding pipe is provided with a plurality of branch pipes, and the high-temperature combustion-supporting air is conveyed into a short flame combustion chamber 12 at the periphery of the furnace body and a long flame combustion chamber 13 at the periphery of the furnace body for ignition and combustion supporting. Because the ignition point of the biomass powder is only 300-350 ℃, a combustion area is formed by direct ignition when high-temperature air is met.

The outlet of the first combustion-supporting fan 5 is divided into two pipelines, a first combustion-supporting air pipeline 28 is connected with the porous air distributor 2, the other second combustion-supporting air pipeline 29 is connected with the air inlet of the honeycomb type waste heat fuel drying device 3, the supplied combustion-supporting air is preheated outside the furnace in the honeycomb type waste heat fuel drying device 3, after five-stage preheating, the combustion-supporting air reaches about 400 ℃, the high-temperature combustion-supporting air is connected with the hot air surrounding pipe 6 outside the furnace through the pipeline, and the high-temperature combustion-supporting air is conveyed to the short flame combustion chamber 12 at the periphery of the furnace and the long flame combustion chamber 13 at the periphery of the furnace for ignition and combustion supporting.

After the heat exchange of lime in the cooling zone is finished, the temperature of the lime is reduced to 70-150 ℃, about 70% of the lime enters the rotary lime discharging device 20 through the peripheral discharging bin 15, the peripheral discharging pipe 16 and the movable material flow control device 17, the rest 30% of the lime also synchronously enters the unidirectional rotary lime discharging device 20 through the central discharging bin 18 and the liftable material flow control device 19, the unidirectional rotary lime discharging device 20 distributes the lime to the plurality of metering devices 21 through the unidirectional rotary and material distribution device, the metered lime enters the lime discharging bin 23 through the discharging controller 22, and the lime discharging and discharging process of the whole lime is finished through the two-stage sealing discharger 24.

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. Accordingly, such modifications and improvements are intended to be within the scope of this invention without departing from the spirit thereof.

Claims

1. The central burner type lime kiln is characterized by comprising a shaft furnace body, a furnace central burner, an opposite double-helix quantitative feeding device, a porous air distributor and a honeycomb type waste heat fuel drying device, wherein a combustion zone of the shaft furnace body is provided with a furnace peripheral combustion chamber, the furnace central burner is arranged on an axis in the shaft furnace body and is positioned below the furnace peripheral combustion chamber, the opposite double-helix quantitative feeding device is connected with the porous air distributor in a working procedure, the porous air distributor is connected with a material inlet of the honeycomb type waste heat fuel drying device, a smoke inlet of the honeycomb type waste heat fuel drying device is connected with the top of the shaft furnace body through a pipeline, and a material outlet of the honeycomb type waste heat fuel drying device is connected with the furnace peripheral combustion chamber and the furnace central burner.

2. The lime kiln as set forth in claim 1, wherein the honeycomb type waste heat fuel drying apparatus is a multi-stage drying apparatus comprising an in-furnace feeding section and an out-furnace feeding section, wherein multi-duct type passages are provided in the in-furnace feeding section and the out-furnace feeding section, the porous air distributor is connected to the material inlets of the in-furnace feeding section and the out-furnace feeding section through two ducts, the material outlets of the in-furnace feeding section are connected to the multi-layer blowing chambers of the in-furnace central burner one-to-one through a plurality of independent ducts, and the material outlets of the out-furnace feeding section are connected to the outer-furnace peripheral combustion chambers one-to-one through a plurality of independent ducts.

3. The lime kiln as recited in claim 2, wherein the honeycomb type waste heat fuel drying device further comprises a plurality of combustion-supporting gas heating sections, the plurality of combustion-supporting gas heating sections being connected in series; the lime kiln further comprises a first combustion-supporting fan, the first combustion-supporting fan is connected with the porous air distributor through a pipeline, the first combustion-supporting fan is connected with an air inlet at the head of the section of the combustion-supporting gas heating section in series connection through another pipeline, and a combustion-supporting gas outlet at the tail of the section of the combustion-supporting gas heating section in series connection is connected with the combustion chamber around the outside of the lime kiln through a pipeline.

4. The lime kiln of claim 3 wherein the furnace peripheral combustion chamber includes at least one furnace peripheral short flame combustion chamber and at least one furnace peripheral flat long flame combustion chamber, the furnace peripheral short flame combustion chamber being located above the furnace peripheral flat long flame combustion chamber.

5. The lime kiln of claim 4 wherein the outer peripheral combustion chamber further comprises an outer peripheral inclined flameless combustion chamber located below the outer peripheral flat flameless combustion chamber and above the inner central burner, the outer peripheral inclined flameless combustion chamber being adapted to emit an obliquely downward flow of combustion supporting gas towards the inner central burner.

6. The lime kiln as recited in claim 5, further comprising a second combustion fan, a high temperature heat storage device and an external hot air surrounding pipe, wherein a cooling channel is arranged in the furnace central burner, the second combustion fan is connected with the cooling channel in the furnace central burner through a pipeline, the high temperature heat storage device is arranged at the top of the shaft furnace body, the outlet of the cooling channel in the furnace central burner is connected with the high temperature heat storage device through a pipeline, the high temperature heat storage device is connected with the external hot air surrounding pipe through a descending pipeline, and the material outlet of the external feeding section of the honeycomb type waste heat fuel drying device is connected with the external peripheral combustion chamber through a corresponding pipeline and the external hot air surrounding pipe.

7. The lime kiln of claim 1 further comprising a combustion air cap disposed at the bottom center of the shaft furnace body and the shaft furnace body is located below the furnace center burner.

8. The lime kiln of claim 1, further comprising a stone weighing device, a feeding trolley and a lifting rotary distributor, which are sequentially connected, wherein the stone weighing device and the feeding trolley are arranged outside the shaft furnace body, and the lifting rotary distributor is arranged at the top of the shaft furnace body.

9. The lime kiln of claim 1, further comprising a peripheral discharge bin, a peripheral discharge pipe, a movable material flow control device, a central discharge bin, a liftable material flow control device, a unidirectional rotation ash discharge device, a metering device, a discharge controller, an ash discharge bin and a two-stage sealing discharger, wherein the peripheral discharge bin and the central discharge bin are arranged at the bottom of the shaft furnace body, the peripheral discharge bin is uniformly distributed on the peripheral side of the central discharge bin, the unidirectional rotation ash discharge device is arranged below the central discharge bin, the peripheral discharge bin is connected with the unidirectional rotation ash discharge device through the peripheral discharge pipe, the movable material flow control device is arranged in the peripheral discharge pipe, the liftable material flow control device is arranged at the bottom of the central discharge bin, the unidirectional rotation ash discharge device is connected with the metering device, the metering device is provided with the ash discharge bin, the metering device is provided with the discharge controller, and the ash discharge bin is connected with the two-stage sealing discharger.