CN113149470B

CN113149470B - External combustion annular sleeve kiln system and lime production method

Info

Publication number: CN113149470B
Application number: CN202110336341.6A
Authority: CN
Inventors: 王长春; 索明金; 汪小龙; 梁晶晶
Original assignee: Beijing Kalu Jinre Wind Furnace Technology Co ltd
Current assignee: Beijing Kalu Jinre Wind Furnace Technology Co ltd
Priority date: 2021-03-29
Filing date: 2021-03-29
Publication date: 2023-09-08
Anticipated expiration: 2041-03-29
Also published as: CN113149470A

Abstract

The embodiment of the invention provides an external combustion annular sleeve kiln system and a lime production method, comprising a sleeve kiln system for calcining limestone and a high-temperature hot blast furnace system for providing high-temperature hot air for the sleeve kiln system, wherein the high-temperature hot blast furnace system is arranged outside the sleeve kiln system and is connected with the sleeve kiln system through a pipeline; wherein: the sleeve kiln system comprises a preheating zone, an upper countercurrent calcining zone, a middle countercurrent calcining zone, a lower cocurrent calcining zone and a cooling zone which are sequentially arranged from top to bottom; the first hot air branch pipe is communicated with the bottom end of the upper air chamber; the second hot air branch pipe is communicated with the top end of the lower air chamber; the high-temperature hot blast stove system comprises a hot blast stove group for generating high-temperature hot blast by combusting low-calorific-value fuel; the first hot air branch pipe is connected with the first hot air ring pipe, and the second hot air branch pipe is connected with the second hot air ring pipe; the first hot air branch pipe is provided with a first regulating valve, and the second hot air branch pipe is provided with a second regulating valve. So that the limestone mineral materials have relatively stable calcination environment during calcination.

Description

External combustion annular sleeve kiln system and lime production method

Technical Field

The invention relates to the field of lime calcination, in particular to an external combustion annular sleeve kiln system and a lime production method.

Background

The annular sleeve kiln is invented by German Bei Kenba He company in the beginning of 60 th of the last century and consists of a kiln shell built with refractory materials and an inner sleeve divided into an upper section and a lower section, wherein the kiln shell and the inner sleeve are concentrically arranged, and materials are positioned in annular spaces of the kiln shell and the inner sleeve so as to be beneficial to air flow penetration. The upper inner sleeve is hung at the top of the kiln, the lower inner sleeve is positioned at the lower part of the shaft kiln, the structure of the upper inner sleeve is that a double-layer steel shell forms an annular gap, air is introduced into the annular gap for cooling, and the inner side and the outer side of the annular gap are built with refractory linings. The upper inner sleeve and the lower inner sleeve have different functions, the upper inner sleeve mainly pumps out high-temperature waste gas to preheat jet air, the lower inner sleeve mainly is used for generating circulating airflow to form parallel-flow calcination, and the effect of ensuring uniform distribution of the airflow is achieved.

The annular sleeve kiln is generally provided with two layers of combustion chambers, the number of each layer of combustion chambers is 3-7 according to the yield of the kiln, and the combustion chambers are connected with the inner sleeve through arch bridges built by refractory materials. The fuel used by the annular sleeve kiln is generally fluid fuel, the annular sleeve kiln can be divided into a preheating zone, an upper countercurrent calcining zone, a middle countercurrent calcining zone, a lower parallel flow calcining zone and a cooling zone from top to bottom, wherein the preheating zone refers to the bottom of the kiln top to the bottom of the upper inner sleeve, the upper countercurrent calcining zone refers to the bottom of the upper inner sleeve to the upper combustion chamber, the middle countercurrent calcining zone refers to the upper combustion chamber to the lower combustion chamber, the lower parallel flow calcining zone refers to the lower combustion chamber to the circulating gas inlet, the cooling zone refers to the circulating gas inlet to the discharging platform discharging machine, and lime is finally burned in the lower parallel flow calcining zone.

The air flow in the annular sleeve kiln is divided into five types: lime cooling air, inner sleeve cooling air (wherein the lower inner sleeve cooling air is combustion air), driving wind, circulating wind and exhaust gas.

Wherein, lime cooling air is naturally sucked into a kiln discharging bin through an air pipe under the micro negative pressure environment in the kiln, and after lime is cooled in the bin, the lime enters the kiln through a gap between finished products of a discharging machine of a discharging platform. After passing through the cooling belt in the kiln, the air enters the upper section of the lower inner sleeve through the circulating gas inlet and forms circulating air together with the rest gas.

The inner sleeve cooling air is divided into lower inner sleeve cooling air and upper inner sleeve cooling air. The cooling air of the lower inner sleeve is discharged out of the lower inner sleeve by an inner sleeve cooling air duct (in an upper arch bridge) at the upper part of the upper section of the lower inner sleeve, and then is led into a lower annular pipe on a kiln heat exchanger platform by a pipeline, and a plurality of branch pipes are further led to burners of the upper and lower combustion chamber platforms to be used as combustion air of the burners; the upper inner sleeve cooling air is discharged through a main pipe and directly discharged to the atmosphere.

The driving air is conveyed into a heat exchanger on a heat exchanger platform of the kiln through a pipeline, after heat exchange, the air at normal temperature is heated to 350-500 ℃, and then is conveyed to a driving air ring pipe on the heat exchanger platform through a hot air outlet pipe of the heat exchanger, and then enters an injection pipe and is sprayed out at high speed to be used as the power of circulating gas in the kiln.

The circulating gas is high-temperature gas generated by combustion in the lower combustion chamber, and after passing through the parallel flow calcining zone, the circulating gas is mixed with lime cooling air at a circulating gas inlet and enters the part of mixed gas in the upper section of the lower inner sleeve. The circulating gas flows from the circulating gas duct below the inner sleeve cooling air duct into the injector where it enters the lower combustion chamber together with the driving wind so as to circulate.

The waste gas refers to waste smoke generated by combustion in the annular sleeve kiln, and finally flows towards the kiln top under the action of the high-temperature waste gas fan. Under the distribution of a kiln top gas flow regulating valve, about 67% of waste flue gas enters a preheating zone between an upper inner sleeve and a kiln shell, and finally enters a waste gas induced draft fan through a kiln top waste gas pipeline; in addition, about 33% of the flue gas enters the heat exchanger through the inner sleeve and the pipeline to be used as a preheating air source for driving air, the temperature of the flue gas entering the heat exchanger is about 750-800 ℃, the temperature is reduced to about 350-450 ℃ after heat exchange, and then the flue gas enters the flue gas pipeline. All waste gas in the kiln is pumped out by a waste gas induced draft fan, and is discharged into the atmosphere through a chimney after the dust removal of the bag type dust remover reaches the national waste gas emission standard.

The heat required for combustion in the annular kiln is provided by the fuel supplied from the outside. The fuel is injected into the combustion chamber through the burner, and the high-temperature gas generated by combustion enters the material layer through the space formed at the lower part of the arch bridge, so as to provide heat for calcination in the kiln. The fuel quantity supplied by the upper burner and the lower burner of the annular sleeve kiln is different, and the distribution ratio is about: up/down=1/1.5 to 2.2. The amount of combustion air provided by the upper combustion chamber is only about 50%, the combustion air required by supplying fuel to the lower combustion chamber for combustion is excessive, the air excess coefficient is about 2.0, and the high-temperature flue gas (the temperature is less than 1350 ℃) generated by the combustion of the lower combustion chamber is divided into two parts: one part flows to the kiln top through the middle countercurrent calcining zone and the upper countercurrent calcining zone, and the other part flows downwards under the negative pressure pumping force generated by the high-speed airflow of the jet pipe, so that a cocurrent flow calcining zone is formed between the lower combustion chamber and the circulating gas inlet of the lower inner sleeve.

Annular sleeve kiln is invented based on high heat value combustion, and the initially used fuel is natural gas and heavy oil. As energy supply becomes increasingly intense, new energy applications in annular sleeve kilns are continually explored.

When the heat value is reduced to 1200kcal/Nm ³ Or lower, the existing sleeve kiln has the main problems that: the penetration of the hot air flow in the lime material layer is reduced, the temperature of the lower combustion chamber is low, the circulating gas quantity is insufficient, the circulating gas temperature is lower than the required temperature of the calcined qualified lime, the ash outlet temperature is higher, the waste gas quantity is large, the heat consumption is high due to high temperature, and the like.

Disclosure of Invention

The embodiment of the invention provides an external combustion annular sleeve kiln system and a lime production method, which enable limestone mineral aggregate to have a relatively stable calcination environment during calcination.

In order to achieve the above purpose, in one aspect, the embodiment of the invention provides an external combustion annular sleeve kiln system, which comprises a sleeve kiln system for calcining limestone and a high-air-temperature hot-air furnace system for providing high-temperature hot air for the sleeve kiln system, wherein the high-air-temperature hot-air furnace system is arranged outside the sleeve kiln system and is connected with the sleeve kiln system through a pipeline; wherein:

The sleeve kiln system comprises a kiln body, wherein the kiln body comprises a kiln shell, an upper inner sleeve arranged in the kiln shell and concentric with the kiln shell, and a lower inner sleeve arranged in the kiln shell and concentric with the kiln shell, and the upper inner sleeve is arranged above the lower inner sleeve at intervals; the upper inner sleeve is arranged in a manner that the nozzle of the upper inner sleeve is downward and inverted, and the lower inner sleeve is arranged in a manner that the nozzle of the lower inner sleeve is downward and inverted;

the kiln shell is provided with a kiln top, and the upper inner sleeve is connected to the kiln top;

the sleeve kiln system also comprises an upper air chamber and a lower air chamber; the upper air chamber is arranged at the upper part in a space formed by the lower inner sleeve and the kiln shell; the upper air chamber is connected with the lower inner sleeve through an arch bridge;

the lower air chamber is arranged at the lower part in a space formed by the lower inner sleeve and the kiln shell; the lower air chamber is connected with the lower inner sleeve through an arch bridge;

the sleeve kiln system comprises a preheating zone, an upper countercurrent calcining zone, a middle countercurrent calcining zone, a lower cocurrent calcining zone and a cooling zone which are sequentially arranged from top to bottom;

the preheating zone is formed by a space between the upper inner sleeve and the kiln shell;

the upper countercurrent calcining zone is formed by a space from the nozzle of the upper inner sleeve to the upper air chamber;

The middle countercurrent calcining zone is formed by a space between the upper air chamber and the lower air chamber;

the lower parallel flow calcining zone is formed by the inner space of the lower air chamber and the space from the outlet of the lower air chamber to the mixed air inlet of lime cooling air; wherein, the mixed wind inlet of the lime cooling wind is positioned below the nozzle of the lower inner sleeve;

the cooling belt is formed by a space from a mixed air inlet of the lime cooling air to a discharging machine of the discharging platform;

the sleeve kiln system further comprises a first hot air branch pipe and a second hot air branch pipe;

the first hot air branch pipe is communicated with the upper air chamber; the second hot air branch pipe is communicated with the lower air chamber;

the high-temperature hot blast stove system comprises a hot blast stove group for generating high-temperature hot blast by combusting low-calorific-value fuel; the hot air furnace group is provided with a hot air pipeline for conveying high-temperature hot air outwards, and also comprises a first hot air ring pipe encircling the outer side of the kiln shell and a second hot air ring pipe encircling the outer side of the kiln shell, wherein the first hot air ring pipe and the second hot air ring pipe are respectively connected with the hot air pipeline;

the first hot air branch pipe is connected with the first hot air ring pipe, and the second hot air branch pipe is connected with the second hot air ring pipe;

The sleeve kiln system further comprises a first regulating valve arranged on the first hot air branch pipe and used for regulating the temperature and the flow of the hot air, and a second regulating valve arranged on the second hot air branch pipe and used for regulating the temperature and the flow of the hot air.

In another aspect, an embodiment of the present invention provides a method for producing lime in an external combustion annular sleeve kiln, including: the high-temperature hot blast furnace system is arranged outside the sleeve kiln system and is connected with the sleeve kiln system through a pipeline; wherein:

the method for producing lime by using the external combustion annular sleeve kiln comprises the following steps:

connecting said upper inner sleeve to said kiln crown of said kiln shell;

An upper air chamber is arranged in the sleeve kiln system, and the upper air chamber is arranged at the upper part in a space formed by the lower inner sleeve and the kiln shell;

a lower air chamber is arranged in the sleeve kiln system, and the lower air chamber is arranged at the lower part in a space formed by the lower inner sleeve and the kiln shell;

the low-heat value fuel is combusted through a hot air furnace group included in the high-air temperature hot air furnace system to generate high-temperature hot air, and the high-temperature hot air generated by combusting the low-heat value fuel through the hot air furnace group is conveyed outwards through a hot air pipeline of the hot air furnace group; the high-temperature hot air conveyed outwards by the hot air pipeline is conveyed to a first hot air ring pipe which is connected with the hot air pipeline and surrounds the outer side of the kiln shell, and the high-temperature hot air flowing through the first hot air ring pipe is conveyed to the bottom end inside the upper air chamber through a first hot air branch pipe which is communicated with the first hot air branch pipe and is communicated with the bottom end of the upper air chamber; before the high-temperature hot air is conveyed to the bottom end of the upper air chamber, the temperature and the flow rate of the high-temperature hot air are regulated by a first regulating valve arranged on a first hot air branch pipe;

the high-temperature hot air which is conveyed outwards by the hot air pipeline is also conveyed to a second hot air ring pipe which is connected with the hot air pipeline and surrounds the outer side of the kiln shell, and the high-temperature hot air flowing through the second hot air ring pipe is conveyed to the top end of the interior of the lower air chamber through a second hot air branch pipe which is communicated with the top end of the lower air chamber; before the high-temperature hot air is conveyed to the top end of the interior of the lower air chamber, the temperature and the flow rate of the high-temperature hot air are regulated by a second regulating valve arranged on a second hot air branch pipe;

A preheating zone, an upper countercurrent calcining zone, a middle countercurrent calcining zone, a lower cocurrent calcining zone and a cooling zone which are sequentially arranged in the sleeve kiln system from top to bottom; wherein:

the preheating zone is formed at the kiln top by a space between the upper inner sleeve and the kiln shell, limestone mineral materials in the feeding trolley are added into the kiln body through a feeding mechanism, and the limestone mineral materials are preheated by flue gas rising from the upper countercurrent calcining zone and the middle countercurrent calcining zone when passing through the preheating zone;

the upper countercurrent calcining zone is formed by a space from a nozzle of the upper inner sleeve to the upper air chamber, preheated limestone mineral materials enter the upper countercurrent calcining zone for calcining, and the upper countercurrent calcining zone calcines the limestone mineral materials by high-temperature hot air conveyed into the upper air chamber from a first hot air branch pipe and flue gas raised by the middle countercurrent calcining zone;

the middle countercurrent calcining zone is formed by a space between the upper air chamber and the lower air chamber; the limestone mineral materials calcined in the upper countercurrent calcining zone are countercurrent calcined from the upper air chamber to the middle countercurrent calcining zone, and the limestone mineral materials are calcined in the middle countercurrent calcining zone through high-temperature hot air which enters from the second hot air branch pipe and flows reversely upwards;

The lower parallel flow calcining zone is formed by the space from the inner space of the lower air chamber to the mixed air inlet of lime cooling air; wherein, the mixed wind inlet of the lime cooling wind is positioned below the nozzle of the lower inner sleeve; complete calcination of limestone mineral materials is completed in the lower parallel-flow calcination zone through the parallel-flow heating of hot air entering from the second hot air branch pipe, and active lime is generated; the cooling belt is formed by a space from a mixed air inlet of the lime cooling air to a discharging machine of the discharging platform; under the mixed wind inlet for delivering active lime to lime cooling wind, entering the cooling belt, and cooling the active lime in the cooling belt;

lime cooling air after cooling active lime enters the lower inner sleeve through a mixed air inlet of lime cooling air under the action of negative pressure,

and discharging the cooled material to a kiln discharging bin by a discharging machine of a sleeve kiln discharging platform.

The technical scheme has the following beneficial effects: so that the limestone mineral materials have relatively stable calcination environment during calcination.

Drawings

In order to more clearly illustrate the embodiments of the invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a cross-sectional view of a kiln body of an embodiment of the invention primarily for use in illustrating an external combustion annular sleeve kiln system;

FIG. 2 is a diagram of the connection relationship between a kiln top heat exchanger and the kiln body of FIG. 1, which is mainly used for showing an external combustion annular sleeve kiln system according to an embodiment of the invention;

FIG. 3 is a diagram showing the connection relationship between the hot air stack 2 and the kiln body of FIG. 1 of an external combustion annular sleeve kiln system according to an embodiment of the present invention;

FIG. 4 is a diagram of an embodiment of the present invention primarily for illustrating the connection of the outer combustion annular sleeve kiln system 110 to the kiln body of FIG. 1;

FIG. 5 is a diagram of an embodiment of the present invention primarily used to demonstrate the connection of a chimney to the kiln body of FIG. 1;

fig. 6 is a block diagram of an embodiment of the present invention other than the combustion annular sleeve kiln system (the positional relationship and piping connection of fig. 1-5 can be expressed).

The reference numerals are expressed as:

1. a kiln body; 11. an upper inner sleeve; 12. a lower inner sleeve; 13. an upper air chamber; 14. a lower air chamber; 16. a mixed wind inlet of lime cooling wind; 17. the mixed air is discharged out of the channel of the kiln body; 18. a smoke exhaust passage; 19. a kiln top heat exchanger; 110. the cooling wind of the inner sleeve flows from the fan; 111. a first hot air loop; 112. a first regulating valve; 113. a mixed air ring pipe; 2. a hot air furnace group; 21. heat accumulating hot-blast stove; 22. a high temperature heat exchanger; 23. a hot blast stove heat exchanger; 114. a cooling air mixing collar;

15. Lime cools the air inlet.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

As shown in fig. 1, in combination with an embodiment of the present invention, there is provided an external combustion annular sleeve kiln system including a sleeve kiln system for calcining limestone and a high-temperature hot blast furnace system for supplying high-temperature hot blast to the sleeve kiln system, the high-temperature hot blast furnace system being disposed outside the sleeve kiln system and connected to the sleeve kiln system through a pipe.

The sleeve kiln system comprises a kiln body 1, wherein the kiln body 1 is in a cylindrical shape, the bottom of the cylinder is positioned at the upper part, a cylinder opening is arranged upside down, the kiln body 1 comprises a kiln shell, an upper inner sleeve 11 arranged in the kiln shell and concentric with the kiln shell, and a lower inner sleeve 12 arranged in the kiln shell and concentric with the kiln shell, and the upper inner sleeve 11 is arranged above the lower inner sleeve 12 at intervals; and the upper inner sleeve 11 is arranged upside down with the nozzle facing downwards, and the lower inner sleeve 12 is arranged upside down with the nozzle facing downwards.

The kiln shell is provided with a kiln top, and the upper inner sleeve 11 is connected to the kiln top; the sleeve kiln system also comprises an upper air chamber 13 and a lower air chamber 14 or is arranged in the kiln body 1; the upper air chamber 13 is arranged at the upper part in a space formed by the lower inner sleeve 12 and the kiln shell; and the upper air chamber 13 is connected with the lower inner sleeve 12 through an arch bridge; the lower air chamber 14 is arranged at the lower part in the space formed by the lower inner sleeve 12 and the kiln shell; and the lower plenum 14 is coupled to the lower inner sleeve 12 by an arch bridge. Wherein the number of air chambers per layer is determined according to kiln yield.

The sleeve kiln system comprises a preheating zone, an upper countercurrent calcining zone, a middle countercurrent calcining zone, a lower cocurrent calcining zone and a cooling zone which are sequentially arranged from top to bottom; wherein:

the preheating zone is formed by the space between the upper inner sleeve 11 and the kiln shell;

the upper countercurrent calcining zone is formed by the space from the nozzle of the upper inner sleeve 11 downwards to the upper air chamber 13;

the middle countercurrent calcining zone is formed by a space between the upper air chamber 13 and the lower air chamber 14;

the lower parallel flow calcining zone is formed by the inner space of the lower air chamber 14 and the space from the outlet of the lower air chamber 14 to the mixed air inlet 16 of lime cooling air; wherein the mixed wind inlet 16 of the lime cooling wind is arranged below the nozzle of the inner sleeve 12; the mixed air inlet 16 of the lime cooling air is the mixed air inlet of the flue gas and the lime cooling air generated by the parallel flow calcining zone at the lower part.

The cooling belt is formed by a space from a mixed air inlet 16 of the lime cooling air to a discharging machine of the discharging platform.

The raw materials (limestone ore materials) in the feeding trolley are added into the kiln through a feeding mechanism (chute, middle bin and the like) at the top of the kiln, preheated by a preheating zone in the kiln, sequentially calcined by an upper countercurrent calcining zone, a middle countercurrent calcining zone and a lower parallel flow calcining zone in the kiln, cooled by a lime cooling zone after calcined into active lime, and discharged into a kiln discharging bin by a discharging machine of a sleeve kiln discharging platform. When the finished products in the kiln discharging bin reach a high material level, a vibrating discharging machine with a hydraulic gate at the bottom of the kiln discharging bin is started, the finished products in the kiln discharging bin are discharged out of the kiln, and the finished products are conveyed to a finished product system by a high-temperature heat-resistant rubber belt conveyor.

And, compared to prior art sleeve kiln systems, the sleeve kiln system eliminates the burner and associated burner system outside the combustion chamber (plenum) and eliminates the ejector and associated drive wind system. A high-temperature hot blast stove system is adopted.

The sleeve kiln system further comprises a first hot air branch pipe and a second hot air branch pipe; the first hot air branch pipe is communicated with the upper air chamber 13; the second hot air branch pipe is communicated with the lower air chamber 14; the high-temperature hot blast stove system comprises a hot blast stove group 2 for generating high-temperature hot blast by combusting low-calorific-value fuel; the hot air furnace group 2 is provided with a hot air pipeline for conveying high-temperature hot air outwards, the hot air furnace group 2 further comprises a first hot air annular pipe 111 encircling the outer side of the kiln shell and a second hot air annular pipe encircling the outer side of the kiln shell, and the first hot air annular pipe 111 and the second hot air annular pipe are respectively connected with the hot air pipeline; the first hot air branch pipe is connected to the first hot air loop 111, and the second hot air branch pipe is connected to the second hot air loop; the sleeve kiln system further comprises a first regulating valve 112 arranged on the first hot air branch pipe and used for regulating the temperature and the flow of the hot air, and a second regulating valve arranged on the second hot air branch pipe and used for regulating the temperature and the flow of the hot air.

So that the limestone mineral materials have relatively stable calcination environment during calcination: the high-temperature hot air has good penetrating power in the limestone layer, achieves the calcination temperature required by the lower air chamber, and meets the requirement temperature of qualified lime for calcination and reduces the ash discharge temperature from each calcination section upwards of the lower parallel flow calcination belt and the calcination temperature of the preheating section.

Preferably, the hot air furnace group 2 is further divided into two parts, namely a first hot air loop pipe 111 and a second hot air loop pipe which are respectively connected to the middle part of the kiln body 1 from two symmetrical ends, and is further connected to the upper air chamber 13 and the lower air chamber 14 respectively through two hot air branch pipes.

The high-temperature hot air entering from the upper air chamber 13 is mixed with the flue gas (generated by the middle countercurrent calcining section) from bottom to top in the kiln, and then the mineral aggregate is calcined and preheated in sequence upwards, and then a part of the flue gas is discharged out of the kiln body through the upper inner sleeve 11 and the smoke discharge channel 18.

The flue gas formed in the lower parallel flow calcining zone at the lower parallel flow calcining zone heats mineral aggregates, enters the lower inner sleeve 12 from the mixed wind inlet of the lime cooling wind of the lower inner sleeve 12, and is discharged out of the kiln body 1 together with the lime cooling wind from the lime cooling air inlet 15 (the self lime cooling air inlet 15 is connected to the cooling zone through a pipeline).

The air for cooling the finished lime is naturally sucked into a bin under the kiln (kiln bottom) through an air pipe in a negative pressure environment in the kiln body 1 from a lime cooling air inlet 15, after the lime is cooled in the bin, the lime cooling air (waste gas) enters an annular space in the kiln body 1 through a gap between finished products of a discharging machine, enters an upper section inside a lower inner sleeve 12 from a mixed air inlet 16 of the lime cooling air under the action of an external induced draft fan, and the lime cooling air is mixed with high-temperature gas generated by combustion of a lower air chamber after the lime ore material is calcined through a parallel flow calcining zone to form parallel flow flue gas mixed air at the mixed air inlet 16 of the lime cooling air, and the parallel flow flue gas mixed air enters an upper section inside the lower inner sleeve 12 and is then pumped out of the kiln body. Specifically, the parallel flow flue gas mixed air refers to the high-temperature gas entering the lower air chamber from the second hot air branch pipe, after passing through the parallel flow calcining zone of the incompletely calcined mineral aggregate in the lower air chamber, the high-temperature gas is mixed with lime cooling air at the lower inlet (the mixed air inlet 16 of lime cooling air) of the lower inner sleeve 12 to form the parallel flow flue gas mixed air, the parallel flow flue gas mixed air enters the upper section inside the lower inner sleeve 12, and the part of the parallel flow flue gas mixed air is pumped out of the kiln body.

The invention comprehensively adopts the external combustion annular sleeve kiln for calcining the low-calorific-value fuel, and an external high-wind-temperature hot blast furnace system is configured by improving the related structure of the sleeve kiln in the prior art, so that the energy is utilized to the maximum extent.

Preferably, the hot blast stove set 2 comprises a blower and two to four heat accumulating type hot blast stoves 21, and the heat accumulating type hot blast stoves 21 are respectively connected to the blower in a pipeline manner; the working system of 'two-firing one-feeding' is adopted, and high-temperature hot air is continuously blown into the sleeve kiln system. The heat accumulating type hot blast stove 21 is provided with a heat accumulating chamber and a heat accumulator arranged in the heat accumulating chamber for heat exchange, and the heat accumulating type hot blast stove 21 is also provided with a gas input pipeline, the air blower is connected with the gas input pipeline, and the gas input pipeline is used for conveying the gas blown by the air blower into the heat accumulating chamber; the burner is positioned outside the heat accumulation chamber;

the regenerative hot blast stove 21 comprises a low heating value fuel inlet for receiving a low heating value fuel, a burner connected to the low heating value fuel inlet, and the regenerative hot blast stove 21 has a combustion air inlet for receiving combustion air, the combustion air inlet being connected to the burner; the heat accumulator is heated by the flue gas generated by combustion of the combustion air combustion-supporting low-calorific-value fuel in the combustor, and the heated heat accumulator exchanges heat with the gas entering the heat accumulator to form high-temperature hot air from the gas of the heat accumulator;

The heat accumulating type hot air furnace 21 is provided with a high-temperature hot air outlet; the high-temperature hot air outlet is connected with the hot air pipeline; high-temperature hot air is blown into the sleeve kiln system through the hot air pipeline.

Wherein, the heat accumulating type hot blast stove 21 is provided with three seats.

Wherein the low heating value fuel is a low heating value gas fuel; the low heating value gas fuel comprises blast furnace gas. In large metallurgical enterprises, the gas abundance of the blast furnace is relatively large, and the heat value of the blast furnace is 700-800 kcal/Nm ³ On the left and right, many metallurgical enterprises use the gas for power generation, and redundant gas is diffused, so that the energy waste is caused to a great extent, and serious environmental pollution is caused. Therefore, the low-calorific-value fuel such as blast furnace gas is comprehensively used in the annular sleeve kiln, the quality and the yield can be ensured, and the method becomes the most important research content of lime engineering design and is also the development direction of the annular sleeve kiln technology in the future.

The lime calcining process with converter gas burning fume by using high temperature hot air to replace the original annular sleeve kiln can use low heat value fuel such as blast furnace gas, and all waste heat can be utilized, so that fuel consumption and fuel cost can be effectively reduced. The high-blast-temperature hot blast stove can realize low nitrogen emission and meet the emission standard of nitrogen oxides, so that the invention substantially improves the emission environment-friendly level of the calcined lime of the sleeve kiln.

Preferably, the sleeve kiln system further comprises a smoke exhaust channel 18, a chimney and an exhaust gas induced draft fan (not shown in the figure) for extracting exhaust gas in the kiln, wherein the exhaust gas induced draft fan pipeline is connected to the smoke exhaust channel 18, and the smoke exhaust channel 18 is connected to the kiln top.

The smoke evacuation channel 18 has a first smoke evacuation branch and a second smoke evacuation branch; the second smoke exhaust branch pipe is connected with the chimney; the first exhaust branch pipe is used for discharging high-temperature smoke discharged from the upper inner sleeve 11, and the second exhaust branch pipe is used for discharging low-temperature smoke discharged from the kiln body.

The high-temperature hot blast stove system further comprises a kiln top heat exchanger 19 for preheating combustion air, one end of the kiln top heat exchanger 19 is connected with a first smoke exhaust branch pipe of the smoke exhaust channel 18, and the other end of the kiln top heat exchanger 19 is connected with the hot blast stove group 2; the kiln top heat exchanger 19 is provided with a smoke inlet and a smoke outlet, the smoke inlet of the kiln top heat exchanger 19 is connected with a first smoke exhaust branch pipe of the smoke exhaust channel 18, and the smoke outlet of the kiln top heat exchanger 19 is connected with a second smoke exhaust branch pipe of the smoke exhaust channel 18; the kiln top heat exchanger 19 has an inlet combustion air inlet and a combustion air outlet; the combustion air outlet of the kiln top heat exchanger 19 is connected with the combustion air inlet of the regenerative hot blast stove 21.

Combustion air enters the kiln top heat exchanger 19 through a combustion air inlet, and is preheated by flue gas discharged through the flue gas discharge channel 18. The combustion air is cooled after being preheated, and is converged with the unused waste gas (low-temperature flue gas) discharged from the kiln roof (second smoke discharging branch pipe), and is discharged into a chimney (the dust remover is not shown in the schematic diagram) after being dedusted by the dust remover. The flue gas is formed by preheating mineral aggregate upwards by the calcined high-temperature flue gas, and the flue gas is gradually cooled in the process. The smoke is removed (higher than 250 deg) from the upper inner sleeve 11 at the high temperature of the smoke, and the rest of the smoke continues to preheat the mineral aggregate, so that the smoke discharged from the kiln roof is not at that high temperature, i.e. the low temperature smoke (not higher than 250 deg).

The hot blast stove group 2 further comprises a high-temperature heat exchanger 22 for secondarily preheating combustion air, and the high-temperature heat exchanger 22 is arranged between the kiln top heat exchanger 19 and the heat accumulating type hot blast stove 21;

the high-temperature heat exchanger 22 is provided with a combustion air inlet and a combustion air outlet, and the combustion air inlet of the high-temperature heat exchanger 22 is connected with the combustion air outlet of the kiln top heat exchanger 19; the combustion air outlet of the high-temperature heat exchanger 22 is connected with the combustion air inlet of the heat accumulating type hot blast stove 21;

The sleeve kiln system also comprises a mixed air discharging kiln body channel 17 for conveying the mixed air of the parallel-flow flue gas outwards, wherein the mixed air discharging kiln body channel 17 is communicated with the top of the lower inner sleeve 12 and penetrates out of the kiln shell;

the sleeve kiln system further comprises a mixed air ring pipe 113 communicated with the channel 17 of the mixed air discharging kiln body, and one end of the mixed air ring pipe 113 is connected with the channel 17 of the mixed air discharging kiln body; the other end of the mixed air ring pipe 113 is connected to the high-temperature heat exchanger 22;

the high temperature heat exchanger 22 has an exhaust cooling gas inlet and an exhaust cooling gas outlet;

the other end of the mixed air ring pipe 113 is connected to the waste cooling gas inlet of the high-temperature heat exchanger 22; the parallel flow flue gas mixed air discharged from the mixed air ring pipe 113 enters the high temperature heat exchanger 22 after being dedusted by a deduster; the waste cooling gas outlet of the high-temperature heat exchanger 22 is connected with a chimney; and the parallel flow flue gas is mixed with the preheated combustion air and then cooled, and is discharged into a chimney after being dedusted by a deduster (the deduster is not shown in the schematic diagram).

Wherein, all waste gas (so-called waste gas can be considered as gas after the initial function is finished, such as cooling waste wind after cooling wind finishes cooling lime, all hot wind entering the lime kiln is waste wind after calcining is finished, or calcining flue gas) in the kiln is pumped out by a waste gas induced draft fan, about 67% of waste flue gas enters a preheating zone between the upper inner sleeve 11 and the kiln shell under the distribution of a kiln top gas flow regulating valve, and finally enters the waste gas induced draft fan from a kiln top waste gas pipeline to be discharged into the atmosphere; in addition, about 33% of the flue gas enters the kiln top heat exchanger 19 through the inner sleeve 11 through a pipeline, the temperature is reduced to about 350-450 ℃ after heat exchange, and then the flue gas enters the flue gas pipeline to be mixed with the other part of the flue gas. And then the dust is removed by a bag type dust remover to reach the emission standard, and the dust is discharged into the atmosphere through a chimney.

Preferentially, the hot air furnace group 2 is provided with a flue gas discharge channel for discharging flue gas generated by burning low-calorific-value fuel;

the high-air-temperature hot blast stove system further comprises a hot blast stove heat exchanger 23, and the hot blast stove heat exchanger 23 is connected with a flue gas discharge channel of the hot blast stove group 2;

the hot blast stove heat exchanger 23 is provided with a smoke inlet and a smoke outlet, and the hot blast stove heat exchanger 23 is provided with a low-heat-value fuel inlet and a low-heat-value fuel outlet; the smoke inlet of the hot blast stove heat exchanger 23 is connected with a smoke discharge channel of the hot blast stove group 2, and the smoke outlet of the hot blast stove heat exchanger 23 is connected with a chimney;

the low-calorific-value fuel outlet of the hot blast stove heat exchanger 23 is connected with the hot blast stove group 2;

the high blast temperature hot blast stove system further comprises a fuel delivery pipeline for providing low heat value fuel for the hot blast stove group 2, wherein the fuel delivery pipeline is connected to the low heat value fuel inlet of the hot blast stove heat exchanger 23, and the low heat value fuel is delivered to the low heat value fuel inlet of the hot blast stove heat exchanger 23 through the fuel delivery pipeline.

The gas is preheated by using the waste heat of the flue gas discharged after the heat accumulating type hot blast stove 21 burns, and the hot blast stove group 2 burns by adopting the preheated combustion air and the gas, so that the fuel consumption can be reduced.

Preferably, the upper inner sleeve 11 is a sandwich metal structure and the lower inner sleeve 12 is a sandwich metal structure;

the external combustion annular sleeve kiln system further comprises an inner sleeve cooling air slave fan 110; the inner sleeve cooling wind is respectively connected with the sandwich metal structure of the upper inner sleeve 11 and the sandwich metal structure of the lower inner sleeve 12 through pipelines from the fan 110; the upper inner sleeve 11 has an upper inner sleeve waste cooling wind discharge passage, the lower inner sleeve 12 has a lower inner sleeve waste cooling wind discharge passage discharging cooling wind in the lower inner sleeve, and the upper inner sleeve waste cooling wind discharge passage and the inner sleeve waste cooling wind discharge passage communicate with a cooling wind mixing collar 114, respectively. Enters the high temperature heat exchanger 22 for re-preheating the already preheated combustion air. That is, the inner sleeve cooling air is divided into cooling air after cooling the lower inner sleeve and cooling air after cooling the upper inner sleeve. The upper inner sleeve cooling air and the lower inner sleeve cooling air are exhausted through the corresponding pipelines respectively and serve as preheated combustion-supporting air.

There is also provided, in connection with an embodiment of the present invention, a method of producing lime in an externally fired annular sleeve kiln, comprising: the high-temperature hot blast furnace system is arranged outside the sleeve kiln system and is connected with the sleeve kiln system through a pipeline; wherein:

The sleeve kiln system comprises a kiln body 1, wherein the kiln body 1 comprises a kiln shell, an upper inner sleeve 11 arranged in the kiln shell and concentric with the kiln shell, and a lower inner sleeve 12 arranged in the kiln shell and concentric with the kiln shell, and the upper inner sleeve 11 is arranged above the lower inner sleeve 12 at intervals; the upper inner sleeve 11 is arranged upside down by adopting a nozzle, and the lower inner sleeve 12 is arranged upside down by adopting a nozzle;

connecting said upper inner sleeve 11 to said kiln roof of said kiln shell;

an upper air chamber 13 is arranged in the sleeve kiln system, and the upper air chamber 13 is arranged at the upper part of a space formed by the lower inner sleeve 12 and the kiln shell;

and a lower plenum 14 is arranged in the sleeve kiln system, and the lower plenum 14 is arranged at the lower part in a space formed by the lower inner sleeve 12 and the kiln shell;

the low-heat-value fuel is combusted through a hot air furnace group 2 included in the high-air-temperature hot air furnace system to generate high-temperature hot air, and the low-heat-value fuel is combusted through the hot air furnace group 2 to generate high-temperature hot air which is conveyed outwards through a hot air pipeline of the hot air furnace group; the high-temperature hot air which is conveyed outwards by the hot air pipeline is conveyed to a first hot air ring pipe 111 which is connected with the hot air pipeline and surrounds the outer side of the kiln shell, and the high-temperature hot air which flows through the first hot air ring pipe 111 is conveyed to the bottom end inside the upper air chamber 13 through a first hot air branch pipe which is communicated with the bottom end of the upper air chamber 13 by a first hot air branch pipe; the high temperature hot air temperature and flow rate are regulated by a first regulating valve 112 arranged on a first hot air branch pipe before the high temperature hot air is delivered to the bottom end of the inside of the upper air chamber 13;

The high-temperature hot air which is conveyed outwards by the hot air pipeline is also conveyed to a second hot air ring pipe which is connected with the hot air pipeline and surrounds the outer side of the kiln shell, and the high-temperature hot air flowing through the second hot air ring pipe is conveyed to the top end of the interior of the lower air chamber 14 through a second hot air branch pipe which is communicated with the top end of the lower air chamber 14; before the high-temperature hot air is delivered to the top end of the interior of the lower plenum 14, the temperature and the flow rate of the high-temperature hot air are regulated by a second regulating valve arranged on a second hot air branch pipe;

the preheating zone is formed at the kiln top by the space between the upper inner sleeve 11 and the kiln shell, limestone mineral materials in the feeding trolley are added into the kiln body 1 through the feeding mechanism, and the limestone mineral materials are preheated by flue gas rising from the upper countercurrent calcining zone and the middle countercurrent calcining zone when passing through the preheating zone;

the upper countercurrent calcining zone is formed by a space from a nozzle of the upper inner sleeve 11 downwards to the upper air chamber 13, preheated limestone mineral materials enter the upper countercurrent calcining zone for calcining, and the upper countercurrent calcining zone calcines the limestone mineral materials by high-temperature hot air conveyed into the upper air chamber 13 from a first hot air branch pipe and flue gas raised by the middle countercurrent calcining zone;

The middle countercurrent calcining zone is formed by a space between the upper air chamber 13 and the lower air chamber 14; the limestone mineral materials calcined in the upper countercurrent calcining zone are countercurrent calcined from the upper air chamber 13 to the middle countercurrent calcining zone, and the limestone mineral materials are calcined in the middle countercurrent calcining zone through high-temperature hot air which enters from the second hot air branch pipe and is countercurrent upwards;

the lower parallel flow calcining zone is jointly formed by the space from the lower plenum 14 to the mixed wind inlet 16 of lime cooling wind; wherein the mixed wind inlet 16 of the lime cooling wind is positioned below the nozzle of the lower inner sleeve 12; the lower parallel flow calcining zone heats the flue gas which is generated from the kiln body 1 and rises from the middle part of the lower part of the kiln body through the hot air entering from the second hot air branch pipe in parallel flow, and the complete calcination of the limestone ore quantity is completed together to generate active lime;

the cooling belt is formed by a space from a mixed air inlet 16 of the lime cooling air to a discharging machine of the discharging platform; under the mixed wind inlet 16, which delivers active lime to the lime cooling wind, into the cooling zone, where the active lime is cooled;

lime cooling air after cooling the active lime is introduced into the lower inner sleeve 12 through the mixed air inlet 16 of the lime cooling air under the effect of the negative pressure,

Preferably, the hot blast stove group 2 is provided with a blower and two to four heat accumulating hot blast stoves 21 which are respectively connected through pipelines;

the blower conveys gas to a regenerator of the regenerative hot blast stove 21 through a gas input pipeline of the regenerative hot blast stove 21, and the gas enters a regenerator for heat exchange in the regenerator;

inputting the low heating value fuel into a burner connected to the low heating value fuel inlet through the low heating value fuel inlet of the regenerative hot blast stove 21;

the combustion air inlet is connected with the burner, and the combustion air is conveyed into the burner through the combustion air inlet which is provided with the heat accumulating type hot blast stove 21 and receives the combustion air;

combustion-supporting low-calorific-value fuel by combustion-supporting air in the combustor to generate smoke;

the flue gas is generated by burning the low-calorific-value fuel to heat the heat accumulator, and the heated heat accumulator exchanges heat with the gas entering the heat accumulator to form high-temperature hot air from the gas of the heat accumulator;

the hot air outlet of the heat accumulating type hot air furnace 21 is used for conveying the high-temperature hot air to a hot air pipeline;

Wherein, the hot air furnace group 2 is provided with an air blower and three heat accumulating type hot air furnaces 21 which are respectively connected by pipelines;

the low heating value fuel is inputted into a burner connected to the low heating value fuel inlet through the low heating value fuel inlet which is provided with the regenerative hot blast stove 21 and comprises the following specific components:

the low-heat value fuel is low-heat value gas fuel; the low heating value gas fuel comprises blast furnace gas.

Preferably, the method comprises the steps of,

the interior of the kiln body 1 is changed into a negative pressure environment by an exhaust gas induced draft fan for extracting exhaust gas in the kiln body 1;

exhaust gas in the section kiln body 1 is discharged outwards through the exhaust gas channel 18; the waste gas comprises high-temperature flue gas exhausted from the upper inner sleeve 11 and low-temperature flue gas exhausted from the kiln body;

the high-temperature flue gas discharged from the upper inner sleeve 11 is discharged through a first flue gas discharging branch pipe arranged in the flue gas discharging channel 18, and the discharged high-temperature flue gas enters the kiln top heat exchanger 19 from a flue gas inlet arranged in the kiln top heat exchanger 19;

the kiln top heat exchanger 19 is provided with an inlet for inlet combustion air and is used for receiving combustion air, and the combustion air in the kiln top heat exchanger 19 is preheated;

the kiln top heat exchanger 19 is provided with a combustion air outlet connected with a combustion air inlet of the heat accumulating type hot blast stove 21; the preheated combustion air is discharged through a combustion air outlet of the kiln top heat exchanger 19 and enters a combustion air inlet of the heat accumulating type hot blast stove 21;

The waste gas preheated by the combustion air in the kiln top heat exchanger 19 is discharged to a second smoke discharging branch pipe arranged in the smoke discharging channel 18 through a smoke outlet arranged in the kiln top heat exchanger 19;

the second smoke exhaust branch pipe is used for exhausting low-temperature smoke exhausted from the kiln body;

the flue gas entering the second flue gas exhaust branch pipe is exhausted to a chimney connected with the flue gas exhaust branch pipe;

a high-temperature heat exchanger 22 for secondarily preheating combustion air is arranged in the hot blast stove group 2, and the high-temperature heat exchanger 22 is arranged on a combustion air circulation path between the kiln top heat exchanger 19 and the heat accumulating type hot blast stove 21;

the sleeve kiln system is provided with a mixed air discharging kiln body channel 17 for outwards conveying mixed air of parallel-flow flue gas, and the mixed air discharging kiln body channel 17 is communicated with the top of the lower inner sleeve 12 and penetrates out of the kiln shell;

the sleeve kiln system is also provided with a mixed air ring pipe 113 communicated with the channel 17 of the mixed air discharging kiln body, and one end of the mixed air ring pipe 113 is connected with the channel 17 of the mixed air discharging kiln body; delivering co-current flue gas mixture exiting the kiln body through the mixture loop 113 into the high temperature heat exchanger 22; wherein the parallel flow flue gas mixed wind flowing through the mixed wind loop 113 enters the high temperature heat exchanger 22 through a waste cooling gas inlet of the high temperature heat exchanger 22;

The high temperature heat exchanger 22 has a combustion air inlet and a combustion air outlet; preheated combustion air exiting the combustion air outlet of the kiln top heat exchanger 19 enters the high temperature heat exchanger 22 from a combustion air inlet provided in the high temperature heat exchanger 22;

secondary preheating of combustion air is performed by co-current flue gas mixture entering the high temperature heat exchanger 22; delivering the secondary preheated combustion air to the combustion air inlet of the regenerative hot blast stove 21 through the combustion air outlet of the high temperature heat exchanger 22;

the co-current flue gas mixture after the secondary pre-heating of the combustion air is discharged to the stack through the high temperature heat exchanger 22 with an exhaust cooling gas outlet.

Preferably, the method comprises the steps of,

the hot air furnace group 2 is provided with a flue gas discharge channel for discharging flue gas generated by burning low-calorific-value fuel;

the high-air-temperature hot blast stove system is also provided with a hot blast stove heat exchanger 23, and the hot blast stove heat exchanger 23 is connected with a flue gas discharge channel of the hot blast stove group 2;

the hot blast stove heat exchanger 23 is provided with a smoke inlet and a smoke outlet, and the smoke inlet of the hot blast stove heat exchanger 23 is connected with a smoke discharge channel of the hot blast stove group 2; flue gas generated by burning low-calorific-value fuel discharged from the hot blast stove group 2 enters the hot blast stove heat exchanger 23;

Delivering low-heat-value fuel to a low-heat-value fuel inlet of the hot blast stove heat exchanger 23 through a fuel delivery pipeline, wherein the low-heat-value fuel enters the hot blast stove heat exchanger 23 from the low-heat-value fuel inlet of the hot blast stove heat exchanger 23; preheating the low-heat-value fuel through the flue gas generated by burning the low-heat-value fuel entering from the flue gas inlet of the hot blast stove heat exchanger 23, and enabling the preheated low-heat-value fuel to enter the low-heat-value fuel inlet of the low-heat-value fuel of the hot blast stove group 2 through the low-heat-value fuel outlet of the hot blast stove heat exchanger 23;

and discharging the flue gas generated by burning the low-heating-value fuel after preheating the low-heating-value fuel into a chimney.

the inner sleeve cooling air is blown into the sandwich metal structure of the upper inner sleeve 11 from the fan 110 through a pipeline to cool the sandwich metal structure of the upper inner sleeve 11, and the waste cooling air cooled by the sandwich metal structure of the upper inner sleeve 11 is discharged into the cooling air mixing ring pipe 114 through an upper inner sleeve waste cooling air discharging channel;

Cooling the sandwich metal structure of the lower inner sleeve 12 by blowing cooling air from the fan 110 through a pipe into the sandwich metal structure of the lower inner sleeve 12 by means of the inner sleeve cooling air and discharging the spent cooling air at the sandwich metal structure of the lower inner sleeve 12 cooled by means of the lower inner sleeve spent cooling air discharge channel into the cooling air mixing collar 114.

It should be understood that the specific order or hierarchy of steps in the processes disclosed are examples of exemplary approaches. Based on design preferences, it is understood that the specific order or hierarchy of steps in the processes may be rearranged without departing from the scope of the present disclosure. The accompanying method claims present elements of the various steps in a sample order, and are not meant to be limited to the specific order or hierarchy presented.

In the foregoing detailed description, various features are grouped together in a single embodiment for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments of the subject matter require more features than are expressly recited in each claim. Rather, as the following claims reflect, invention lies in less than all features of a single disclosed embodiment. Thus the following claims are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate preferred embodiment of this invention.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present application. As will be apparent to those skilled in the art; various modifications to these embodiments will be readily apparent, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the disclosure. Thus, the present disclosure is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

The foregoing description includes examples of one or more embodiments. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing the aforementioned embodiments, but one of ordinary skill in the art may recognize that many further combinations and permutations of various embodiments are possible. Accordingly, the embodiments described herein are intended to embrace all such alterations, modifications and variations that fall within the scope of the appended claims. Furthermore, as used in the specification or claims, the term "comprising" is intended to be inclusive in a manner similar to the term "comprising," as interpreted when employed as a transitional word in a claim. Furthermore, any use of the term "or" in the specification of the claims is intended to mean "non-exclusive or".

The foregoing description of the embodiments has been provided for the purpose of illustrating the general principles of the invention, and is not meant to limit the scope of the invention, but to limit the invention to the particular embodiments, and any modifications, equivalents, improvements, etc. that fall within the spirit and principles of the invention are intended to be included within the scope of the invention.

Claims

1. The external combustion annular sleeve kiln system is characterized by comprising a sleeve kiln system for calcining limestone and a high-air-temperature hot-air furnace system for providing high-temperature hot air for the sleeve kiln system, wherein the high-air-temperature hot-air furnace system is arranged outside the sleeve kiln system and is connected with the sleeve kiln system through a pipeline; wherein:

the sleeve kiln system comprises a kiln body (1), wherein the kiln body (1) comprises a kiln shell, an upper inner sleeve (11) arranged in the kiln shell and concentric with the kiln shell, and a lower inner sleeve (12) arranged in the kiln shell and concentric with the kiln shell, and the upper inner sleeve (11) is arranged above the lower inner sleeve (12) at intervals; the upper inner sleeve (11) is arranged upside down by adopting a nozzle, and the lower inner sleeve (12) is arranged upside down by adopting a nozzle;

The kiln shell is provided with a kiln top, and the upper inner sleeve (11) is connected to the kiln top;

the sleeve kiln system also comprises an upper air chamber (13) and a lower air chamber (14); the upper air chamber (13) is arranged at the upper part in a space formed by the lower inner sleeve (12) and the kiln shell; the upper air chamber (13) is connected with the lower inner sleeve (12) through an arch bridge;

the lower air chamber (14) is arranged at the lower part in a space formed by the lower inner sleeve (12) and the kiln shell; and the lower air chamber (14) is connected with the lower inner sleeve (12) through an arch bridge;

the preheating zone is formed by a space between the upper inner sleeve (11) and the kiln shell;

the upper countercurrent calcining zone is jointly formed by a space from the nozzle of the upper inner sleeve (11) downwards to the upper air chamber (13);

the middle countercurrent calcining zone is formed by a space between the upper air chamber (13) and the lower air chamber (14);

the lower parallel flow calcining zone is formed by the inner space of the lower air chamber (14) and the space from the outlet of the lower air chamber (14) to the mixed air inlet (16) of lime cooling air; wherein the mixed wind inlet (16) of the lime cooling wind is positioned below the nozzle of the lower inner sleeve (12);

The cooling belt is formed by a space from a mixed air inlet (16) of the lime cooling air to a discharging machine of the discharging platform;

the first hot air branch pipe is communicated with the upper air chamber (13); the second hot air branch pipe is communicated with the lower air chamber (14);

the high-temperature hot blast stove system comprises a hot blast stove group (2) for generating high-temperature hot blast by combusting low-calorific-value fuel; the hot air furnace group (2) is provided with a hot air pipeline for conveying high-temperature hot air outwards, the hot air furnace group (2) further comprises a first hot air ring pipe (111) encircling the outer side of the kiln shell and a second hot air ring pipe encircling the outer side of the kiln shell, and the first hot air ring pipe (111) and the second hot air ring pipe are respectively connected with the hot air pipeline;

the first hot air branch pipe is connected to the first hot air ring pipe (111), and the second hot air branch pipe is connected to the second hot air ring pipe;

the sleeve kiln system also comprises a first regulating valve (112) arranged on the first hot air branch pipe and used for regulating the temperature and the flow of the hot air, and a second regulating valve arranged on the second hot air branch pipe and used for regulating the temperature and the flow of the hot air;

the hot air furnace group (2) comprises a blower and two to four heat accumulating type hot air furnaces (21), and the heat accumulating type hot air furnaces (21) are respectively connected with the blower through pipelines; the heat accumulating type hot blast stove (21) is provided with a heat accumulating chamber and a heat accumulator arranged in the heat accumulating chamber and used for heat exchange, the heat accumulating type hot blast stove (21) is also provided with a gas input pipeline, the air blower is connected with the gas input pipeline, and the gas input pipeline is used for conveying gas blown by the air blower into the heat accumulating chamber; the burner is positioned outside the heat accumulation chamber;

The regenerative hot blast stove (21) comprises a low heating value fuel inlet for receiving low heating value fuel, a burner connected to the low heating value fuel inlet, and the regenerative hot blast stove (21) is provided with a combustion air inlet for receiving combustion air, the combustion air inlet is connected with the burner; the heat accumulator is heated by the flue gas generated by combustion of the combustion air combustion-supporting low-calorific-value fuel in the combustor, and the heated heat accumulator exchanges heat with the gas entering the heat accumulator to form high-temperature hot air from the gas of the heat accumulator;

the heat accumulating type hot air furnace (21) is provided with a high-temperature hot air outlet; the high-temperature hot air outlet is connected with the hot air pipeline;

the sleeve kiln system further comprises a smoke exhaust channel (18), a chimney and an exhaust gas induced draft fan for extracting exhaust gas in the kiln body (1), wherein the exhaust gas induced draft fan is connected with the smoke exhaust channel (18) through a pipeline, and the smoke exhaust channel (18) is connected with the kiln top;

the smoke exhaust channel (18) is provided with a first smoke exhaust branch pipe and a second smoke exhaust branch pipe; the second smoke exhaust branch pipe is connected with the chimney; the first smoke exhaust branch pipe is used for exhausting high-temperature smoke exhausted from the upper inner sleeve (11), and the second smoke exhaust branch pipe is used for exhausting low-temperature smoke exhausted from the kiln body;

The high-temperature hot blast stove system further comprises a kiln top heat exchanger (19) for preheating combustion air, one end of the kiln top heat exchanger (19) is connected with a first smoke exhaust branch pipe of the smoke exhaust channel (18), and the other end of the kiln top heat exchanger (19) is connected with the hot blast stove group (2);

the kiln top heat exchanger (19) is provided with a smoke inlet and a smoke outlet, the smoke inlet of the kiln top heat exchanger (19) is connected with a first smoke discharging branch pipe of the smoke discharging channel (18), and the smoke outlet of the kiln top heat exchanger (19) is connected with a second smoke discharging branch pipe of the smoke discharging channel (18);

the kiln top heat exchanger (19) is provided with an inlet combustion air inlet and a combustion air outlet;

the combustion air outlet of the kiln top heat exchanger (19) is connected with the combustion air inlet of the heat accumulating type hot blast stove (21);

the hot blast stove group (2) further comprises a high-temperature heat exchanger (22) for secondarily preheating combustion air, and the high-temperature heat exchanger (22) is arranged between the kiln top heat exchanger (19) and the heat accumulating type hot blast stove (21);

the high-temperature heat exchanger (22) is provided with a combustion air inlet and a combustion air outlet, and the combustion air inlet of the high-temperature heat exchanger (22) is connected with the combustion air outlet of the kiln top heat exchanger (19); the combustion air outlet of the high-temperature heat exchanger (22) is connected with the combustion air inlet of the heat accumulating type hot blast stove (21);

The sleeve kiln system also comprises a mixed air discharging kiln body channel (17) for conveying the mixed air of the parallel-flow flue gas outwards, and the mixed air discharging kiln body channel (17) is communicated with the top of the lower inner sleeve (12) and penetrates out of the kiln shell;

the sleeve kiln system further comprises a mixed air ring pipe (113) communicated with the channel (17) of the mixed air discharging kiln body, and one end of the mixed air ring pipe (113) is connected with the channel (17) of the mixed air discharging kiln body; the other end of the mixed air ring pipe (113) is connected with the high-temperature heat exchanger (22);

the high temperature heat exchanger (22) has an exhaust cooling gas inlet and an exhaust cooling gas outlet;

the other end of the mixed air ring pipe (113) is connected with an exhaust cooling gas inlet of the high-temperature heat exchanger (22);

the waste cooling gas outlet of the high-temperature heat exchanger (22) is connected with a chimney;

the upper inner sleeve (11) is of a sandwich metal structure and the lower inner sleeve (12) is of a sandwich metal structure;

the external combustion annular sleeve kiln system further comprises an inner sleeve cooling air slave fan (110); the inner sleeve cooling air is respectively connected with the interlayer metal structure of the upper inner sleeve (11) and the interlayer metal structure of the lower inner sleeve (12) through pipelines from the fan (110), and the inner sleeve cooling air is respectively blown into the interlayer metal structure of the upper inner sleeve (11) and the interlayer metal structure of the lower inner sleeve (12) through the pipelines from the fan (110); the upper inner sleeve (11) is provided with an upper inner sleeve waste cooling air discharging channel for discharging cooling air in the upper inner sleeve, the lower inner sleeve (12) is provided with a lower inner sleeve waste cooling air discharging channel for discharging cooling air in the lower inner sleeve, and the upper inner sleeve waste cooling air discharging channel and the inner sleeve waste cooling air discharging channel are respectively communicated with a cooling air mixing ring pipe (114).

2. The external combustion annular sleeve kiln system of claim 1 wherein,

the heat accumulating type hot blast stove (21) is provided with three seats;

3. The external combustion annular sleeve kiln system according to claim 1, characterized in that the hot air furnace group (2) is provided with a flue gas discharge channel for discharging flue gas generated by burning low-calorific-value fuel;

the high-air-temperature hot blast stove system further comprises a hot blast stove heat exchanger (23), and the hot blast stove heat exchanger (23) is connected to a flue gas discharge channel of the hot blast stove group (2);

the hot blast stove heat exchanger (23) is provided with a smoke inlet and a smoke outlet, and the hot blast stove heat exchanger (23) is provided with a low-heat-value fuel inlet and a low-heat-value fuel outlet; the smoke inlet of the hot blast stove heat exchanger (23) is connected with a smoke discharge channel of the hot blast stove group (2), and the smoke outlet of the hot blast stove heat exchanger (23) is connected with a chimney;

the low-calorific-value fuel outlet of the hot blast stove heat exchanger (23) is connected with the hot blast stove group (2);

the high-air-temperature hot blast stove system further comprises a fuel conveying pipeline for providing low-heat-value fuel for the hot blast stove group (2), wherein the fuel conveying pipeline is connected to the low-heat-value fuel inlet of the hot blast stove heat exchanger (23), and the low-heat-value fuel is conveyed to the low-heat-value fuel inlet of the hot blast stove heat exchanger (23) through the fuel conveying pipeline.

4. A method for producing lime in an externally fired annular sleeve kiln comprising: the high-temperature hot blast furnace system is arranged outside the sleeve kiln system and is connected with the sleeve kiln system through a pipeline; wherein:

connecting the upper inner sleeve (11) to a kiln roof provided with the kiln shell;

an upper air chamber (13) is arranged in the sleeve kiln system, and the upper air chamber (13) is arranged at the upper part in a space formed by the lower inner sleeve (12) and the kiln shell;

a lower air chamber (14) is arranged in the sleeve kiln system, and the lower air chamber (14) is arranged at the lower part in a space formed by the lower inner sleeve (12) and the kiln shell;

The low-heat-value fuel is combusted through a hot air furnace group (2) included in the high-air-temperature hot air furnace system to generate high-temperature hot air, and the low-heat-value fuel is combusted by the hot air furnace group (2) to generate the high-temperature hot air which is conveyed outwards through a hot air pipeline of the hot air furnace group; the high-temperature hot air which is conveyed outwards by the hot air pipeline is conveyed to a first hot air ring pipe (111) which is connected with the hot air pipeline and surrounds the outer side of the kiln shell, and the high-temperature hot air which flows through the first hot air ring pipe (111) is conveyed to the bottom end in the upper air chamber (13) through a first hot air branch pipe which is communicated with the bottom end of the upper air chamber (13); before the high-temperature hot air is conveyed to the bottom end of the upper air chamber (13), the temperature and the flow rate of the high-temperature hot air are regulated by a first regulating valve (112) arranged on a first hot air branch pipe;

the high-temperature hot air which is conveyed outwards by the hot air pipeline is also conveyed to a second hot air ring pipe which is connected with the hot air pipeline and surrounds the outer side of the kiln shell, and the high-temperature hot air flowing through the second hot air ring pipe is conveyed to the top end of the interior of the lower air chamber (14) through a second hot air branch pipe which is communicated with the top end of the lower air chamber (14); before the high-temperature hot air is conveyed to the top end inside the lower air chamber (14), the temperature and the flow rate of the high-temperature hot air are regulated by a second regulating valve arranged on a second hot air branch pipe;

the preheating zone is formed at the kiln top by a space between the upper inner sleeve (11) and the kiln shell, limestone mineral materials in the feeding trolley are added into the kiln body (1) through the feeding mechanism, and the limestone mineral materials are preheated by flue gas rising from the upper countercurrent calcining zone and the middle countercurrent calcining zone when passing through the preheating zone;

the upper countercurrent calcining zone is formed by a space from a nozzle of the upper inner sleeve (11) downwards to the upper air chamber (13), preheated limestone mineral materials enter the upper countercurrent calcining zone for calcining, and the upper countercurrent calcining zone calcines the limestone mineral materials through high-temperature hot air conveyed into the upper air chamber (13) from a first hot air branch pipe and flue gas raised by the middle countercurrent calcining zone;

the middle countercurrent calcining zone is formed by a space between the upper air chamber (13) and the lower air chamber (14); the limestone mineral materials calcined in the upper countercurrent calcining zone are calcined from the upper air chamber (13) to the middle countercurrent calcining zone, and the limestone mineral materials are calcined in the middle countercurrent calcining zone through high-temperature hot air which enters from the second hot air branch pipe and flows reversely upwards;

The lower parallel-flow calcining zone is jointly formed by the space from the lower air chamber (14) to a mixed air inlet (16) of lime cooling air; wherein the mixed wind inlet (16) of the lime cooling wind is positioned below the nozzle of the lower inner sleeve (12); complete calcination of limestone mineral materials is completed in the lower parallel-flow calcination zone through the parallel-flow heating of hot air entering from the second hot air branch pipe, and active lime is generated;

the cooling belt is formed by a space from a mixed air inlet (16) of the lime cooling air to a discharging machine of the discharging platform; under a mixed wind inlet (16) for delivering active lime to a lime cooling wind, entering the cooling zone where the active lime is cooled;

lime cooling air after cooling the active lime enters the lower inner sleeve (12) through a mixed air inlet (16) of lime cooling air under the action of negative pressure,

discharging the cooled material to a kiln discharging bin by a discharging machine of a sleeve kiln discharging platform;

the method for producing lime by using the external combustion annular sleeve kiln further comprises the following steps:

the hot air furnace group (2) is provided with an air blower and two to four heat accumulating hot air furnaces (21) which are respectively connected through pipelines;

the blower conveys gas to a heat accumulation chamber of the heat accumulation type hot blast stove (21) through a gas input pipeline of the heat accumulation type hot blast stove (21), and the gas enters a heat accumulation chamber for heat exchange;

Inputting a low heating value fuel into a burner connected to the low heating value fuel inlet through a low heating value fuel inlet provided to the regenerative hot blast stove (21) and receiving the low heating value fuel;

connecting a combustion air inlet to the burner, and delivering combustion air into the burner through a combustion air inlet of the regenerative hot blast stove (21) provided with a combustion air receiving inlet;

the hot air outlet of the heat accumulating type hot air furnace (21) is used for conveying high-temperature hot air to the hot air pipeline;

the interior of the kiln body (1) is changed into a negative pressure environment through an exhaust gas induced draft fan for extracting exhaust gas in the kiln body (1);

exhaust gas in the kiln body (1) is discharged outwards through the exhaust gas channel (18); the waste gas comprises high-temperature flue gas exhausted from the upper inner sleeve (11) and low-temperature flue gas exhausted from the kiln body;

high-temperature flue gas discharged from the upper inner sleeve (11) is discharged through a first smoke discharging branch pipe arranged in the smoke discharging channel (18), and the discharged high-temperature flue gas enters the kiln top heat exchanger (19) from a flue gas inlet arranged in the kiln top heat exchanger (19);

The kiln top heat exchanger (19) is provided with an inlet combustion air inlet for receiving combustion air, and the combustion air in the kiln top heat exchanger (19) is preheated;

a combustion air outlet of the kiln top heat exchanger (19) is connected with a combustion air inlet of the heat accumulating type hot blast stove (21); the preheated combustion air is discharged through a combustion air outlet of the kiln top heat exchanger (19) and enters a combustion air inlet of the heat accumulating type hot blast stove (21);

exhaust gas after combustion air preheating in the kiln top heat exchanger (19) is discharged to a second exhaust branch pipe arranged in the exhaust gas channel (18) through a smoke outlet arranged in the kiln top heat exchanger (19);

a high-temperature heat exchanger (22) for secondarily preheating combustion air is arranged in the hot blast stove group (2), and the high-temperature heat exchanger (22) is arranged on a combustion air circulation path between the kiln top heat exchanger (19) and the heat accumulating type hot blast stove (21);

the sleeve kiln system is provided with a mixed air discharging kiln body channel (17) for outwards conveying mixed air of parallel-flow flue gas, and the mixed air discharging kiln body channel (17) is communicated with the top of the lower inner sleeve (12) and penetrates out of the kiln shell;

The sleeve kiln system is also provided with a mixed air ring pipe (113) communicated with a channel (17) of the mixed air discharging kiln body, and one end of the mixed air ring pipe (113) is connected with the channel (17) of the mixed air discharging kiln body; delivering co-current flue gas mixture air discharged from a channel (17) of the mixture air discharge kiln body into the high-temperature heat exchanger (22) through the mixture air ring pipe (113); wherein the parallel flow flue gas mixed wind flowing through the mixed wind ring pipe (113) enters the high-temperature heat exchanger (22) through an exhaust cooling gas inlet arranged on the high-temperature heat exchanger (22);

the high temperature heat exchanger (22) has a combustion air inlet and a combustion air outlet; preheated combustion air discharged from a combustion air outlet of the kiln top heat exchanger (19) enters the high-temperature heat exchanger (22) from a combustion air inlet of the high-temperature heat exchanger (22);

the combustion air is preheated secondarily by the parallel flow flue gas mixed wind entering the high-temperature heat exchanger (22); delivering the secondary preheated combustion air to a combustion air inlet of the heat accumulating type hot blast stove (21) through a combustion air outlet of the high temperature heat exchanger (22);

mixing the co-current flue gas after secondary preheating of the combustion air, and discharging the mixture to a chimney through a waste cooling gas outlet of the high-temperature heat exchanger (22);

The method for producing lime by the external combustion annular sleeve kiln comprises the steps that the upper inner sleeve (11) is of a sandwich metal structure, and the lower inner sleeve (12) is of a sandwich metal structure;

the inner sleeve cooling air is blown into the sandwich metal structure of the upper inner sleeve (11) from the fan (110) through a pipeline to cool the sandwich metal structure of the upper inner sleeve (11), and waste cooling air cooled at the sandwich metal structure of the upper inner sleeve (11) is discharged into the cooling air mixing ring pipe (114) through an upper inner sleeve waste cooling air discharge channel;

the inner sleeve cooling air is blown into the sandwich metal structure of the lower inner sleeve (12) from the fan (110) through a pipeline to cool the sandwich metal structure of the lower inner sleeve (12), and the waste cooling air cooled by the sandwich metal structure of the lower inner sleeve (12) is discharged into the cooling air mixing ring pipe (114) through a lower inner sleeve waste cooling air discharge channel.

5. The method for producing lime in an externally fired annular sleeve kiln according to claim 4, wherein,

the hot air furnace group (2) is provided with an air blower and three heat accumulating type hot air furnaces (21) which are respectively connected through pipelines;

The method for inputting the low-heating-value fuel into the burner connected with the low-heating-value fuel inlet through the low-heating-value fuel inlet which is provided with the heat accumulating type hot blast stove (21) and is used for receiving the low-heating-value fuel comprises the following steps:

6. The method for producing lime in an externally fired annular sleeve kiln according to claim 4, comprising:

the hot air furnace group (2) is provided with a flue gas discharge channel for discharging flue gas generated by burning low-calorific-value fuel;

the high-air-temperature hot blast stove system is also provided with a hot blast stove heat exchanger (23), and the hot blast stove heat exchanger (23) is connected with a flue gas discharge channel of the hot blast stove group (2);

the hot blast stove heat exchanger (23) is provided with a smoke inlet and a smoke outlet, and the smoke inlet of the hot blast stove heat exchanger (23) is connected with a smoke discharge channel of the hot blast stove group (2); flue gas generated by burning low-calorific-value fuel discharged from the hot blast stove group (2) enters the hot blast stove heat exchanger (23);

delivering low-heat-value fuel to a low-heat-value fuel inlet of the hot blast stove heat exchanger (23) through a fuel delivery pipeline, wherein the low-heat-value fuel enters the hot blast stove heat exchanger (23) from the low-heat-value fuel inlet of the hot blast stove heat exchanger (23); preheating the low-heat-value fuel through smoke generated by burning the low-heat-value fuel entering from a smoke inlet of the hot blast stove heat exchanger (23), and enabling the preheated low-heat-value fuel to enter a low-heat-value fuel inlet of the low-heat-value fuel of the hot blast stove group (2) through a low-heat-value fuel outlet of the hot blast stove heat exchanger (23);