CN216141564U

CN216141564U - Single-channel pure dry dedusting system for comprehensive utilization of converter flue gas waste heat

Info

Publication number: CN216141564U
Application number: CN202121794748.5U
Authority: CN
Inventors: 侯林泽; 王树斌
Original assignee: Beijing Zhongye Blue Sky Technology Co ltd
Current assignee: Beijing Zhongye Blue Sky Technology Co ltd
Priority date: 2021-08-03
Filing date: 2021-08-03
Publication date: 2022-03-29
Anticipated expiration: 2031-08-03

Abstract

The utility model discloses a single-channel pure dry dedusting system for comprehensive utilization of converter flue gas waste heat, which comprises: the synchronous waste heat recovery subsystem comprises a waste heat boiler, the whole structure of the synchronous waste heat recovery subsystem is a U-shaped structure, the inner wall of a hearth of the waste heat boiler is of an annular water-cooled wall hearth structure, three sections of evaporators are further arranged in the waste heat boiler, the bottoms of the three sections of evaporators are communicated, and the top of the waste heat boiler is communicated with a converter and receives converter flue gas; the converter flue gas dedusting and recycling subsystem comprises a dry method box body, and the dry method box body is communicated with a flue gas outlet of a waste heat boiler. According to the utility modelThe smoke emission of the converter is controlled by the original 40mg/m³Is lifted to<10mg/m³Steam reduction and emission reduction of CO₂About 2.5 ten thousand tons, and the converter was cleaned. The process has the advantages of safety, reliability, stability and benefit, greatly reduces the comprehensive operation cost of enterprises while realizing the standard reaching of the converter flue gas, and has wide market prospect.

Description

Single-channel pure dry dedusting system for comprehensive utilization of converter flue gas waste heat

Technical Field

The utility model belongs to the technical field of waste heat dust removal, and relates to a single-channel pure dry dust removal system for recycling and comprehensively utilizing converter flue gas waste heat.

Background

1. Overview of converter steelmaking

Converter steelmaking is the main steelmaking process in the world at present, according to incomplete statistics, about 80% of steel is produced by converters, China is a big steel-producing country, and since oxygen converters are developed in the 60 th century in 20 th century, about 900 steel converters are important iron and steel enterprises in China at present. In the smelting process of the converter, a large amount of flue gas is generated along with the blowing of oxygen, and the flue gas is called furnace gas in the converter. The furnace gas enters a main flue gas system of a dust removal system through a vaporization smoke hood, or primary dust removal, and the flue gas of the main flue gas system is purified to obtain C0>30％、0₂<2 percent of the gas is called converter gas and enters a converter gas cabinet; c0<30％、0₂>2% of the waste gas is sent to a diffusion tower for diffusion.

Converter flue gas is the most special flue gas in the steel industry, and has three main resources:

firstly, the heat energy is that the converter has large smoke volume within the smelting period, and the smoke volume is 500-700 Nm³Per ton of steel; the temperature in the furnace is very high, and the maximum temperature exceeds 1600 ℃, so that the temperature of the smoke is very high, and the temperature of the smoke reaches 800-1000 ℃ until the smoke enters the outlet of the II section of the vaporization flue, namely before entering a dust removal system;

secondly, the dust content of the converter flue gas containing iron oxide and calcium oxide is high and reaches 80-150g/m³Sometimes up to 200g/m instantaneously³

Thirdly, the flue gas of the converter contains a large amount of CO during the oxygen blowing period, and the content can reach as high as 80 percent.

2. Existing converter flue gas treatment method

At present, converter flue gas purification treatment at home and abroad has two processes:

the first converter gas purification technology developed and researched successfully by Nippon Nissan iron and Kawasaki company in 60 years is called as 'OG' method, namely, the flue gas comes out from the tail end of a vaporization smoke hood and enters a 'primary venturi tube' dust remover, then enters a 'secondary venturi tube' dust remover, the temperature of the flue gas is reduced from 800-1000 ℃ to 73-65 ℃ by water, and the dust content is reduced from 80-150g/m³Reduced to 100mg/m³ThenThe coal gas is recovered or diffused. The process flow is called as a wet dust removal process, and the process has the advantages that the system is safe and reliable; the method has the defects of high water consumption, about 3-5 tons of water per ton of steel, for example, 80-ton converter, 300-500 tons of water per hour, large sewage and sludge treatment capacity, large treatment system, high energy consumption and serious environmental pollution.

The second is that the German thessen company and Lurgi company jointly developed the dry dust removal technology of converter gas in the end of 60 years. The "LI" method is for short. The system mainly comprises an evaporative cooler, an electrostatic precipitator and a gas cooler, wherein flue gas in the process flows out of the end section of the vaporization smoke hood and then enters the evaporative cooler, the temperature of the flue gas is reduced from 800 plus materials to 200 ℃ by adopting double media (steam and water), and then enters the electric precipitator, so that the dust content of the flue gas is reduced to 10mg/m³Then the gas is recovered or diffused. Is in popularization and expansion in the whole country and the whole world. It has low water consumption of 0.5-1.0 t/ton steel, and has no need of huge water, treatment system and dry powder of furnace dust. But the investment is high, and the requirements on management and operation in operation are high.

The existing converter flue gas treatment methods, namely the OG method and the LI method, are developed to be quite complete from the process itself. However, from the analysis of the flue gas resource efficiency of the converter, the common problem is to minimize the flue gas resource efficiency of the converter:

(1) the heat energy of the flue gas at 800-;

(2) the converter C0 coal gas is changed into converter coal gas containing water and steam;

(3) the iron oxide and calcium oxide furnace dust changes the original characteristics and cannot be directly applied.

3. The dust removal process of the existing dust removal process for converter flue gas has the following problems:

(1) no matter the OG method or the LT method, the flue gas cooling and dust removal are realized in a water resource intervention mode, and a large amount of water resources are consumed in the dust removal process. The OG method needs to spray 3-5t/t steel (circulating water, 10-20% of supplementing water); the LT method needs water spraying 0.2t/t steel and steam spraying 0.025t/t steel. Calculated by 100 ten thousand tons of steel produced by an LT method, 20 ten thousand tons of water and 2.5 ten thousand tons of steam are consumed each year: the process of dust removal is a process that consumes water resources.

(2) The water sprayed into the flue gas is changed into steam type flue gas under the high-temperature working condition, so that the flue gas amount is increased, the loads of a subsequent dust remover, a draught fan and a gas cooler are increased, and the power consumption is increased.

(3) The operation income is low, and the flue gas waste heat that can not be fine utilizes and brings economic benefits.

At present, the development of national environmental protection forms realizes ultralow emission as a main task of current environmental protection work in the steel industry so as to realize sustainable green development. The final emission value of the converter primary dedusting system is still 40mg/m in national standard due to the limitation of the process in the current steel-making production process³And the environmental protection ultralow emission of other links is 10mg/m³The standard difference is large. In the process of primary flue gas treatment, a large amount of high sensible heat cannot be recycled, and a large amount of energy is wasted.

SUMMERY OF THE UTILITY MODEL

An object of the present invention is to solve at least the above problems and/or disadvantages and to provide at least the advantages described hereinafter.

The utility model also aims to provide a single-channel pure dry dedusting system for comprehensive utilization of converter flue gas waste heat.

Therefore, the technical scheme provided by the utility model is as follows:

converter flue gas waste heat recovery comprehensive utilization single channel pure dry process dust pelletizing system includes:

the synchronous waste heat recovery subsystem comprises a waste heat boiler, wherein the inner wall of a hearth of the waste heat boiler is of an annular water-cooled wall hearth structure, three sections of evaporators are further arranged in the waste heat boiler, each three section of evaporator comprises a first evaporator group, a second evaporator group and a third evaporator group, the first evaporator group, the second evaporator group and the third evaporator group are sequentially arranged from bottom to top along the vertical direction, the three evaporators are communicated, and the top of the waste heat boiler is communicated with a converter and receives converter flue gas;

and the converter flue gas dedusting and recycling subsystem comprises a dry-method box body, and the dry-method box body is communicated with a flue gas outlet of the waste heat boiler.

Preferably, in the single-channel pure dry dedusting system for comprehensive utilization of converter flue gas waste heat, the method further comprises:

the ash bucket is arranged at the lower part of the waste heat boiler, an ash bucket bottom opening is formed in the bottom of the waste heat boiler, and flue gas output by the ash bucket enters the three-section evaporator;

the dedusting ash treatment system comprises a high-pressure ball press, wherein a feed inlet of the high-pressure ball press is communicated with a bottom opening of an ash bucket of the waste heat boiler, and a discharge outlet of the high-pressure ball press is communicated with a feed inlet of the converter; the boiler dust is collected at the bottom, the dust-collecting pressed block processed by the high-pressure ball press is in a high-temperature state, and the pressed block in the high-temperature state is directly returned to the rotary furnace for use, so that the heating process is omitted;

the dedusting ash processing system is also in gas communication with the dry method box body.

Preferably, the single-channel pure dry dedusting system for recycling the converter flue gas waste heat comprehensively further comprises:

one end of the fan subsystem is communicated with the converter flue gas dust removal recovery subsystem to provide dust removal power;

and the coal gas cooling subsystem is communicated with the other end of the fan subsystem and receives the flue gas, and comprises a coal gas cooler, and the coal gas cooler is provided with a water cooling circulating system.

the converter high-temperature flue gas intelligent combustion system comprises an oxygen removal burner, wherein the oxygen removal burner is arranged between the tail end of a converter vaporization flue and the synchronous waste heat recovery subsystem and is positioned at the upper end of the waste heat boiler, and the oxygen removal burner is communicated with a gas cooler through a liquid pipeline;

and the igniters of the converter high-temperature flue gas intelligent combustion system are arranged in a square matrix, and the CO pipeline is communicated with the middle part of the igniters.

and the gas switching subsystem switches the gas outlet to be communicated with the gas storage device or the waste gas discharge port.

a first gas analyzer disposed between a flue outlet of the converter and the oxygen scavenging burner;

and the second gas analyzer is arranged between the fan subsystem and the coal gas cooling subsystem.

Preferably, in the single-channel pure dry dedusting system for comprehensive utilization of converter flue gas waste heat, 2 groups of sound wave soot blowers capable of moving back and forth are mounted on each group of evaporators, and pulse nitrogen is combined to remove dust and slag on a heating surface.

Preferably, in the converter flue gas waste heat recovery comprehensive utilization single-channel pure dry dedusting system,

the waste heat boiler is designed to be of an anti-seismic and anti-explosion sealing structure, an automatic reset pressure release valve is installed, and negative pressure exists in the waste heat boiler;

and the boiler pipe of the waste heat boiler adopts a pre-spraying measure to spray a special ceramic or metal ceramic coating on the surface of the boiler pipeline. The pre-spraying method adopts a high-temperature plasma jet method or an ultrasonic flame jet method.

Preferably, in the converter flue gas waste heat recovery comprehensive utilization single-channel pure dry dedusting system, the dry box body adopts a bag-type dust remover.

Preferably, in the converter flue gas waste heat recovery comprehensive utilization single-channel pure dry dedusting system, the fan subsystem is configured as two coal gas induced fans.

The utility model at least comprises the following beneficial effects:

the utility model system and method after processingThe furnace smoke emission reaches the standard: the smoke emission of the converter is 40mg/m³Is lifted to<10mg/m³And the steam is reduced into emission reduction CO2, which is about 2.5 ten thousand tons, and the converter is cleaned after the converter.

The process has the advantages of safety, reliability, stability and benefit, creates economic benefit and social benefit while realizing the standard reaching of the converter flue gas, and is suitable for the dust removal process of a newly-built converter.

The BIFS method of the utility model has the economic efficiency of three precious resources of the flue and the economical efficiency of energy conservation and emission reduction of the operation of a new process flow, and the annual economic benefit of a steel plant producing 500 million tons of steel annually is billion yuan. The investment recovery period is about 1.6 years, the comprehensive operation cost of enterprises can be greatly reduced, and the market prospect is wide.

Additional advantages, objects, and features of the utility model will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the utility model.

Drawings

FIG. 1 is a schematic connection diagram of a single-channel pure dry dedusting system for comprehensive utilization of converter flue gas waste heat according to the present invention.

Detailed Description

The present invention is further described in detail below with reference to the attached drawings so that those skilled in the art can implement the utility model by referring to the description text.

It will be understood that terms such as "having," "including," and "comprising," as used herein, do not preclude the presence or addition of one or more other elements or groups thereof.

As shown in fig. 1, the utility model provides a single-channel pure dry dedusting system for recovering and comprehensively utilizing converter flue gas waste heat, which comprises:

the synchronous waste heat recovery subsystem comprises a waste heat boiler, wherein the inner wall of a hearth of the waste heat boiler is of an annular water-cooled wall hearth structure, three sections of evaporators are further arranged in the waste heat boiler, each three section of evaporator comprises a first evaporator group, a second evaporator group and a third evaporator group, the first evaporator group, the second evaporator group and the third evaporator group are sequentially arranged from bottom to top along the vertical direction, the three evaporator groups are communicated with the three evaporator groups, and the top of the waste heat boiler is communicated with a converter to receive converter flue gas;

and the converter flue gas dedusting and recycling subsystem comprises a dry-method box body, and the dry-method box body is communicated with a flue gas outlet of the waste heat boiler. The converter flue gas dedusting recovery subsystem of the utility model has a simplified structure, and is different from the traditional converter flue gas dedusting system in that the circulating cyclone deduster (coarse dedusting) part is reduced, so that the investment cost is saved and the occupied space is reduced on the premise of not influencing the use effect.

Pure dry bag-type dust collector:

(1) ensuring that the fine dust removal system has sufficient dust filtering capacity. An independent backup box body is required to be provided, and offline dust cleaning capability in the operation process is ensured. The ash removing gas adopts inert flame retardant gas.

(2) The flue gas treatment box body has an explosion-proof function, and when flue gas (coal gas) passes through the box body, an explosion-proof valve of the box body is required to be arranged at a key position on the design of the box body due to CO.

(3) The flammable flue gas dust removal system is made into a sealing structure-the theory of isolation of flammable flue gas and air is followed.

(4) The dust removing system for combustible flue gas is made into an anti-explosion and pressure-relief structure, which follows the theory of isolating combustible flue gas from air.

On-line monitoring of CO% and O₂Percent, self-control operation-follow the limit theory of the mixing ratio of CO combustible flue gas and air.

In the above embodiment, it is preferable that the method further includes:

the dedusting ash treatment system comprises a high-pressure ball press, a feeding hole of the high-pressure ball press is communicated with a bottom opening of an ash bucket of the waste heat boiler, a discharging hole of the high-pressure ball press is communicated with a feeding hole of the converter, and furnace dust output by the synchronous waste heat recovery subsystem is treated into blocks by the dedusting ash treatment system and then is input into the converter again; the dedusting ash processing system is also in gas communication with the dry method box body.

The synchronous waste heat recovery subsystem of the utility model: adopt novel exhaust-heat boiler, the converter flue gas gets into the boiler from the top, because of containing CO in the flue gas, so the boiler design structure is antidetonation explosion-proof seal structure to install the automatic re-setting relief valve, the furnace inner wall sets up to annular water-cooling wall, is the negative pressure in the boiler. The flue gas is dedusted by the gravity dedusting process principle through the hearth, the smoke dust falls on the ash bucket under the action of gravity, and the accumulated ash is discharged from the bottom opening of the ash bucket.

Secondly, the natural characteristics of the converter dust are utilized, the plasticity of the converter dust at high temperature is utilized, the converter dust is directly pressed into blocks by a high-pressure ball press, the high-temperature furnace dust is collected, and then the converter dust is returned to the converter for use in a sealed state. The process does not need to add a binder, the strength of the dust briquette is high, and meanwhile, CaO in the briquette is not contacted with moisture in the air, so that the problems of strength reduction and even pulverization of the briquette caused by hydration reaction of CaO are avoided.

The smoke rises upwards and is cooled by the evaporator group, the evaporator group and the evaporator group in sequence, according to the thermodynamic principle, the smoke rises from bottom to top, the heating surface of the smoke and the evaporator is arranged at the bottom of the evaporator, and the deposited ash and the slag are arranged at the upper part of the flue of the waste heat boiler evaporator, so that the use efficiency of the evaporator cannot be influenced, the use environment of the evaporator is well protected, the problem that the heat transfer of the heating surface of the boiler is weakened due to the deposited ash or the slag is solved, the heat efficiency of the boiler is reduced, the production load is reduced, and even the risk of accidental boiler shutdown is avoided. The evaporator can continuously and efficiently exert efficiency. The cooled flue gas is discharged from the upper part and is connected to a bag-type dust collector, and meanwhile, a sound wave soot blower is used and pulse nitrogen is combined to remove soot on the heating surface and slag.

The boiler pipe adopts a pre-spraying measure (high-temperature plasma jet or supersonic flame jet) to spray a special ceramic or metal ceramic coating on the surface of the boiler pipe, the pre-spraying measure has good high temperature resistance, oxidation resistance, adhesion resistance, nodulation resistance and self-cleaning and purifying functions, and the supersonic flame spraying can not only obviously prolong the service life of the boiler pipe:

A. resist the boiler pipe from being washed by the dust or the furnace gas, and prolong the service life of the boiler pipe

B. A layer of ash forms on the boiler tube surface to resist slagging of the boiler dust on the boiler tubes, and the boiler must be taken off-line during the pre-coating process. The good pre-spraying well protects the use environment of the evaporator, solves the problem that the heat transfer of the heating surface of the boiler is weakened due to dust deposition or slag bonding, reduces the thermal efficiency of the boiler, reduces the production load, and even causes the risk of accidental boiler shutdown. The evaporator can continuously and efficiently exert efficiency.

The sound wave soot blower technology (three sections of evaporators are symmetrically provided with 2 groups of sound wave soot blowers each, and nitrogen pulse climbing frames are combined to clear away soot on a heating surface and carry out directional cleaning by aligning the nitrogen pulse climbing frames with the soot deposition and the slag bonding positions on the upper edge of a flue of the evaporator) converts other energy into high-power sound waves (a pressure wave which is propagated in a space medium (gas) in a density wave form) and sends the high-power sound waves into a furnace, and when the soot on the heating surface is repeatedly pulled and pressed by the density wave which is alternately changed at a certain frequency, the soot falls off due to fatigue loosening and is taken away with a flue gas flow or falls to an ash hopper under the action of gravity and is discharged.

During the production and operation of the boiler, ash and slag are deposited on the surfaces of a heating surface, such as a water-cooled wall, a flue and the like, and the problem which is difficult to solve due to long-term troubles is solved. It not only weakens the heat transfer of the heating surface of the boiler, causes the reduction of the thermal efficiency of the boiler and reduces the production load, but also can cause unexpected shutdown when the ash accumulation and the slag bonding on the heating surface are serious, and causes great economic loss. At present, most boilers are provided with steam soot blowers, compressed air soot blowers, steel ball soot blowers and the like, but the traditional soot blowers have the defects of limited soot blowing range, dead corners of soot blowing, high energy consumption, high maintenance cost, inconvenient operation, side effect and the like in operation and performance, the utilization rate is very low, and most boilers are not required to be stopped. Therefore, new techniques must be sought for removing the soot on the heated surface of the boiler and preventing the slagging. The sound wave ash removal technology opens up a new way for boiler ash removal, is widely applied and achieves good effects.

Sixthly, the flue in the boiler body is of a U-shaped structure, the bottom is communicated, after the flue gas is treated by the deoxidizing burner, the flue gas enters an annular water-cooled wall hearth structure from the upper part of the boiler, meanwhile, an ash bucket is arranged at the bottom, coarse dust removal is carried out according to the gravity dust removal principle, high-temperature ash is collected at the bottom of the ash bucket, dust-containing ash (the main components are calcium oxide and iron oxide) is collected at a high temperature of over 600 ℃, and is directly pressed into blocks, the stability of materials can be ensured, the materials are directly returned to the converter to continue to be used as slag forming agents, the cooling agents are used, recycling is realized, the lifting direction of the flue gas is changed simultaneously, and the flue gas is cooled through an evaporator in the rising process of the flue gas.

And seventhly, cooling the flue gas from the inlet temperature of 800-1000 ℃ to below 150 ℃, and then connecting the flue gas to a bag-type dust collector and a coal gas recovery system.

In one embodiment of the present invention, it is preferable that:

one end of the fan subsystem is communicated with the converter flue gas dust removal recovery subsystem to provide dust removal power; the fan subsystem is the main power source of the whole converter primary dedusting system. Is configured as a special coal gas induced draft fan. The motor adopts an explosion-proof motor, can be arranged outdoors, and has the protection grade of IP 55.

The fan subsystem adopts a double-machine configuration and double-machine use mode: the single-machine load can meet the use requirement of the system, and the double-machine load reduction can meet the use requirement of the system, so that enough safety redundancy is ensured to meet the use requirement of the whole system.

In one embodiment of the present invention, it is preferable that the method further comprises

And the coal gas cooling subsystem is communicated with the other end of the fan subsystem and receives the flue gas, and comprises a coal gas cooler, and the coal gas cooler is provided with a water cooling circulating system. The gas cooler is a very important subsystem device in a primary dust removal system of a converter, and mainly reduces the temperature of gas from 110-130 ℃ to 50-70 ℃, so that the temperature of the gas can meet the acceptance standard of a gas cabinet.

The coal gas cooler cools the coal gas in a water cooling mode to reach the standard, the coal gas is cooled in the cooling process, meanwhile, the cooling water (turbine return water) is heated, and the water in the high-temperature section can be sent to a deaerator for deoxidization treatment and then directly supplied to a boiler after being heated; the cooling water of the low temperature section can be used as secondary circulating water.

In one embodiment of the present invention, it is preferable that:

the converter high-temperature flue gas intelligent combustion system comprises an oxygen removal burner, wherein the oxygen removal burner is arranged between the tail end of a converter vaporization flue and the synchronous waste heat recovery subsystem and is positioned at the upper end of the waste heat boiler, and the oxygen removal burner is communicated with a gas cooler through a liquid pipeline; the oxygen removal combustor is equivalent to a firewall, and the situation that the safe operation of the waste heat boiler is influenced by some adverse factors in the smelting process of the converter is prevented.

And the igniter of the converter high-temperature flue gas intelligent combustion system is arranged in a square matrix, the CO pipeline is communicated with the middle part of the igniter, and the converter high-temperature flue gas intelligent combustion system is used for monitoring the gas content in the flue in real time, supplementing CO for auxiliary combustion according to the flue gas components in the flue and realizing intelligent combustion.

A. The method ensures that measures can be taken even if the oxygen content suddenly exceeds the standard when the flue gas or the coal gas passes through, so that the oxygen mixed in the coal gas is eliminated, the safety of a boiler and subsequent equipment is ensured, and unqualified coal gas does not need to be discharged through a discharging tower.

B. Because the components of the converter flue gas are always converted according to different stages of the process stages, the oxygen removal combustor can also convert the flue gas into oxygen-free flue gas completely through the preprocessor after the components of the flue gas are changed due to different process stages for safety reasons, so that the safety of subsequent equipment is ensured.

C. Because the working conditions, medium components and temperature of the boiler are stable, the deoxidizing burner ensures that the flue gas (or coal gas) keeps the dynamic stability of the temperature in the whole process, can keep the long-life operation of the boiler, and can simplify subsequent treatment equipment.

In addition, under the condition of the existing oxygen-removing burner, an automatic explosion suppression reaction device is arranged in a low-temperature area for ensuring safety.

The purpose is as follows: the possibility of mixed escape of combustible and comburent in the previous treatment process is ensured, and open fire is detected in the low-temperature section, so that the open fire is automatically eliminated.

Arranging: in the low-temperature section of the system, the passing medium is monitored, and combustible materials, combustion-supporting materials and open flames are ensured to be under the appropriate temperature condition.

The advantages are that: the gas content in the flue is monitored in real time, CO is supplemented to assist combustion according to smoke components in the flue, the igniter is arranged in a square matrix, the CO pipeline is supplemented from the middle of the igniter, the structural safety is high, and the reaction speed is high. Thereby realizing intelligent combustion.

In one embodiment of the present invention, it is preferable that:

the gas switching subsystem is provided with a gas inlet communicated with the gas cooling subsystem and a gas outlet communicated with the gas storage device and the waste gas discharge port respectively, and the gas switching subsystem switches the gas outlet to be communicated with the gas storage device or the waste gas discharge port; the gas switching subsystem is mainly used for switching medium components between gas and flue gas, so that the gas is ensured to enter a gas chamber, and waste gas enters an exhaust chimney.

In one embodiment of the present invention, it is preferable that:

a second gas analyzer disposed between the fan subsystem and the gas cooling subsystem. The first gas analyzer and the second gas analyzer both adopt laser gas analyzers. The laser gas analyzer is based on the international leading semiconductor laser absorption spectrum technology, namely the single line spectrum measuring technology. The system adopts a modulatable semiconductor laser as a light emitting source, modulates the laser frequency by modulating the working current intensity of the semiconductor laser, and makes the laser scanning range slightly larger than the single absorption spectral line of the gas to be measured, so that when a laser beam with a very long wavelength emitted by the semiconductor laser passes through a measuring tube, the laser beam is subjected to frequency-selective absorption by the gas to be measured, and the laser intensity is attenuated. Therefore, the system utilizes the Beer-Lammbe relation existing between different characteristic absorption lines of different gas components and gas concentration and infrared or laser absorption spectrum, and the concentration of the measured gas can be obtained by detecting the size of the absorption lines (namely laser intensity attenuation information).

In one embodiment of the utility model, preferably, each group of evaporators is provided with 2 groups of sound wave soot blowers capable of reciprocating, each three-section evaporator is symmetrically provided with 2 groups of sound wave soot blowers and combined with a nitrogen pulse climbing frame to clean the heated area soot and the slagging nitrogen pulse climbing frame to align to the soot deposition and slagging position on the flue of the evaporator, so that the directional cleaning is realized.

In one embodiment of the utility model, preferably, the design structure of the waste heat boiler is an anti-seismic and anti-explosion sealing structure, an automatic reset pressure release valve is arranged, and negative pressure is generated in the waste heat boiler; the boiler pipe of the waste heat boiler adopts a pre-spraying measure to spray a special ceramic or metal ceramic coating on the surface of a boiler pipeline, and the pre-spraying method adopts a high-temperature plasma jet or supersonic flame jet method.

In one embodiment of the present invention, preferably, the dry box is a bag-type dust collector.

In one embodiment of the present invention, preferably, the fan subsystem is configured as two gas induced fans.

The utility model also provides a single-channel pure dry dedusting method for comprehensive utilization of converter flue gas waste heat, which comprises the following steps:

providing a synchronous waste heat recovery subsystem, wherein the synchronous waste heat recovery subsystem receives converter flue gas and processes the converter flue gas into dust and flue gas, the synchronous waste heat recovery subsystem comprises a waste heat boiler, the overall structure of the waste heat boiler is of a U-shaped structure, the inner wall of a hearth of the waste heat boiler is of an annular water-cooled wall hearth structure, three sections of evaporators are further arranged in the waste heat boiler, the three sections of evaporators comprise one evaporator group, two evaporator groups and three evaporator groups, which are sequentially arranged from bottom to top along the vertical direction, and the three evaporator groups are communicated with each other and provided with the three evaporator groups;

and providing a converter flue gas dedusting and recycling subsystem which comprises a dry-method box body, wherein the dry-method box body is communicated with a flue gas outlet of the waste heat boiler and is used for filtering flue gas. The converter flue gas dedusting recovery subsystem of the utility model has a simplified structure, and is different from the traditional converter flue gas dedusting system in that the circulating cyclone deduster (coarse dedusting) part is reduced, so that the investment cost is saved and the occupied space is reduced on the premise of not influencing the use effect.

Pure dry bag-type dust collector:

In one embodiment of the present invention, it is preferable that:

the synchronous waste heat recovery subsystem is also provided with an ash bucket, the ash bucket is arranged at the lower part of the waste heat boiler, the bottom of the waste heat boiler is provided with an ash bucket bottom opening, and flue gas output by the ash bucket enters the three-section evaporator after turning;

and the dedusting ash processing system receives the smoke output by the synchronous waste heat recovery subsystem, processes the smoke into blocks and then inputs the blocks into the converter again.

In one embodiment of the present invention, it is preferable that:

providing a fan subsystem, wherein one end of the fan subsystem is communicated with the converter flue gas dust removal recovery subsystem to provide dust removal power;

providing a coal gas cooling subsystem which is communicated with the other end of the fan subsystem and receives flue gas, wherein the coal gas cooling subsystem comprises a coal gas cooler, the coal gas cooler is provided with a water cooling circulation system, and water at the high-temperature section of the coal gas cooler can be sent to a deaerator for deoxidization treatment and then directly supplied to a boiler after being heated; the cooling water of the low temperature section can be used as secondary circulating water. The fan subsystem adopts a double-machine configuration and double-machine use mode: the single-machine load can meet the use requirement of the system, and the double-machine load reduction can meet the use requirement of the system, so that enough safety redundancy is ensured to meet the use requirement of the whole system.

In one embodiment of the present invention, it is preferable that:

providing a converter high-temperature flue gas intelligent combustion system, wherein the converter high-temperature flue gas intelligent combustion system comprises a deoxygenation burner, the deoxygenation burner is arranged between the tail end of a converter vaporization flue and the synchronous waste heat recovery subsystem and is positioned at the upper end of the waste heat boiler, the deoxygenation burner and a gas cooler pass through a liquid pipeline, and the deoxygenation burner receives water from the high-temperature section of the gas cooler, performs deoxygenation treatment and directly supplies the water to the waste heat boiler; the oxygen-removing combustor is communicated with the gas cooler through a liquid pipeline; the oxygen removal combustor is equivalent to a firewall, and the situation that the safe operation of the waste heat boiler is influenced by some adverse factors in the smelting process of the converter is prevented.

In one embodiment of the present invention, it is preferable that:

The igniter of the converter high-temperature flue gas intelligent combustion system is arranged in a square matrix, the CO pipeline is communicated with the middle part of the igniter, and the converter high-temperature flue gas intelligent combustion system is used for monitoring the gas content in the flue in real time, supplementing CO for auxiliary combustion according to the flue gas components in the flue and realizing intelligent combustion

In one embodiment of the present invention, it is preferable that:

a gas switching subsystem is also provided, wherein a gas inlet of the gas switching subsystem is communicated with the gas cooling subsystem, a gas outlet of the gas switching subsystem is respectively communicated with the gas storage device and the waste gas discharge port, and a gas outlet of the gas switching subsystem is switched to be communicated with the gas storage device or the waste gas discharge port;

the first gas analyzer is arranged between the flue outlet of the converter and the oxygen removal burner and is used for detecting the content of carbon monoxide and oxygen in the furnace gas before dust removal; the whole process flow (BIFS method) is characterized in that a set of first gas analyzer is arranged at a flue inlet to detect the content of carbon monoxide, carbon dioxide, oxygen and nitrogen in furnace gas, and the temperature detection range is as follows: -40-120 ℃, humidity detection range: 0-100% RH, resolution: 0.01% VOL, precision: F.S is less than or equal to +/-3 percent.

And the second gas analyzer is arranged between the fan subsystem and the coal gas cooling subsystem and is used for detecting the content of carbon monoxide and oxygen in the furnace gas after dust removal. And a set of second gas analyzer is arranged between the induced draft fan and the coal gas cooler, and is used for detecting the content of carbon monoxide and oxygen in the furnace gas after dust removal. Temperature detection range: -40-120 ℃, humidity detection range: 0-100% RH, resolution: 0.01% VOL, precision: F.S is less than or equal to +/-3 percent.

In order to make the technical solution of the present invention better understood by those skilled in the art, the following examples are now provided for illustration:

a single-channel pure dry dedusting method (a new technical process route-BIFS method) for comprehensive utilization of converter flue gas waste heat comprises the following steps:

the converter flue gas waste heat recovery comprehensive utilization single-channel intelligent combustion full-dry dedusting process (BIFS method for short) is characterized in that converter flue gas is cooled without spraying water, three resources of the converter flue gas become precious resources, and the main process route is shown in figure 1.

The converter flue gas waste heat recovery comprehensive utilization single-channel intelligent combustion full-dry dedusting process is composed of six parts, namely a converter high-temperature flue gas intelligent combustion system, a synchronous waste heat recovery subsystem, a converter flue gas dedusting recovery subsystem, a fan subsystem, a coal gas cooling subsystem, a coal gas switching subsystem and the like, and is characterized in that:

1. converter high temperature flue gas intelligence combustion system.

The addition of the deoxidizing burner (between the tail end of a converter vaporization flue and a flue gas waste heat recovery boiler system, at the top end of the boiler and at a flue gas inlet) is equivalent to a firewall, and the safe operation of the waste heat boiler is prevented from being influenced by some adverse factors in the converter smelting process.

2. Synchronous waste heat recovery subsystem

Adopt novel exhaust-heat boiler, the converter flue gas gets into the boiler from the top, because of containing CO in the flue gas, so the boiler design structure is antidetonation explosion-proof seal structure to install automatic re-setting relief valve, the furnace inner wall sets up to annular water-cooling wall, is the negative pressure in the boiler. The flue gas is dedusted by the gravity dedusting process principle through the hearth, the smoke dust falls on the ash bucket under the action of gravity, and the accumulated ash is discharged from the bottom opening of the ash bucket.

Seventhly, cooling the flue gas from the inlet temperature of 800-1000 ℃ to below 150 ℃, and then connecting the flue gas to a bag-type dust collector and a coal gas recovery system;

3. converter flue gas dust removal recovery subsystem

The converter flue gas dust removal system is simple in structure, and is different from a traditional converter flue gas dust removal system in that the circulation cyclone dust remover (coarse dust removal) part is reduced, so that the investment cost is saved and the occupied space is reduced on the premise of not influencing the use effect.

Pure dry bag-type dust collector:

(5) ensuring that the fine dust removal system has sufficient dust filtering capacity. An independent backup box body is required to be provided, and offline dust cleaning capability in the operation process is ensured. The ash removing gas adopts inert flame retardant gas.

(6) The flue gas treatment box body has an explosion-proof function, and when flue gas (coal gas) passes through the box body, an explosion-proof valve of the box body is required to be arranged at a key position on the design of the box body due to CO.

(7) The flammable flue gas dust removal system is made into a sealing structure-the theory of isolation of flammable flue gas and air is followed.

(8) The dust removing system for combustible flue gas is made into an anti-explosion and pressure-relief structure, which follows the theory of isolating combustible flue gas from air.

(9) And (3) monitoring CO% and O2% on line, and automatically controlling the operation to follow the limit theory of the mixing ratio of CO combustible flue gas and air.

4. Fan subsystem

The fan subsystem is the main power source of the whole converter primary dedusting system. Is configured as a special coal gas induced draft fan. The motor adopts an explosion-proof motor, can be arranged outdoors, and has the protection grade of IP 55.

5. Gas cooling subsystem

The gas cooler is a very important subsystem device in a primary dust removal system of a converter, and mainly reduces the temperature of gas from 110-130 ℃ to 50-70 ℃, so that the temperature of the gas can meet the acceptance standard of a gas cabinet.

6. Gas switching subsystem

The gas switching subsystem is mainly used for switching medium components between gas and flue gas, so that the gas is ensured to enter a gas chamber, and waste gas enters an exhaust chimney.

7. Gas analyzer

The laser gas analyzer is based on the international leading semiconductor laser absorption spectrum technology, namely the single line spectrum measuring technology. The system adopts a modulatable semiconductor laser as a light emitting source, modulates the laser frequency by modulating the working current intensity of the semiconductor laser, and makes the laser scanning range slightly larger than the single absorption spectral line of the gas to be measured, so that when a laser beam with a very long wavelength emitted by the semiconductor laser passes through a measuring tube, the laser beam is subjected to frequency-selective absorption by the gas to be measured, and the laser intensity is attenuated. Therefore, the system utilizes the Beer-Lammbe relation existing between different characteristic absorption lines of different gas components and gas concentration and infrared or laser absorption spectrum, and the concentration of the measured gas can be obtained by detecting the size of the absorption lines (namely laser intensity attenuation information).

The whole process flow (BIFS method) is characterized in that a set of gas analyzer is arranged at a flue inlet to detect the content of carbon monoxide, carbon dioxide, oxygen and nitrogen in furnace gas, and the temperature detection range is as follows: -40-120 ℃, humidity detection range: 0-100% RH, resolution: 0.01% VOL, precision: F.S is less than or equal to +/-3 percent.

And a set of gas analyzer is arranged between the induced draft fan and the gas cooler to detect the content of carbon monoxide and oxygen in the furnace gas after dust removal. Temperature detection range: -40-120 ℃, humidity detection range: 0-100% RH, resolution: 0.01% VOL, precision: F.S is less than or equal to +/-3 percent.

Fourthly, comprehensive utilization of flue gas waste heat of steelmaking converter through single-channel intelligent combustion pure dry method cloth bag dust removal system and process (BIFS method) social benefit

The converter smoke emission reaches the standard:

the smoke emission of the converter is 40mg/m³Is lifted to<10mg/m³Steam reduction and emission reduction of CO₂About 2.5 ten thousand tons, and the converter was cleaned.

The process has the advantages of safety, reliability, stability and benefit, and creates economic benefit and social benefit while realizing the standard reaching of the converter flue gas, and the process is suitable for the dust removal process of a newly-built converter.

The BIFS method has the economic efficiency of three precious resources of a flue and the economical efficiency of energy conservation and emission reduction of the operation of a new process flow, and the annual economic benefit of a steel plant producing 500 million tons of steel annually is billion yuan. The investment recovery period is about 1.6 years, the comprehensive operation cost of enterprises can be greatly reduced, and the market prospect is wide.

The number of modules and the processing scale described herein are intended to simplify the description of the utility model. Applications, modifications and variations of the present invention will be apparent to those skilled in the art.

While embodiments of the utility model have been described above, it is not limited to the applications set forth in the description and the embodiments, which are fully applicable in various fields of endeavor to which the utility model pertains, and further modifications may readily be made by those skilled in the art, it being understood that the utility model is not limited to the details shown and described herein without departing from the general concept defined by the appended claims and their equivalents.

Claims

1. Converter flue gas waste heat recovery comprehensive utilization pure dry dust pelletizing system of single channel, its characterized in that includes:

the synchronous waste heat recovery subsystem comprises a waste heat boiler, the whole structure of the waste heat boiler is of a U-shaped structure, the inner wall of a hearth of the waste heat boiler is of an annular water-cooled wall hearth structure, three sections of evaporators are further arranged in the waste heat boiler, each three section of evaporator comprises a first evaporator group, a second evaporator group and a third evaporator group which are sequentially arranged from bottom to top along the vertical direction, the three evaporator groups are communicated, and the top of the waste heat boiler is communicated with a converter to receive converter flue gas;

2. The converter flue gas waste heat recovery comprehensive utilization single-channel pure dry dedusting system of claim 1, further comprising:

the dedusting ash treatment system comprises a high-pressure ball press, wherein a feed inlet of the high-pressure ball press is communicated with a bottom opening of an ash bucket of the waste heat boiler, and a discharge outlet of the high-pressure ball press is communicated with a feed inlet of the converter;

3. The converter flue gas waste heat recovery comprehensive utilization single-channel pure dry dedusting system of claim 1, further comprising:

4. The converter flue gas waste heat recovery comprehensive utilization single-channel pure dry dedusting system of any one of claims 1 to 3, further comprising:

5. The converter flue gas waste heat recovery comprehensive utilization single-channel pure dry dedusting system of claim 4, further comprising:

6. The converter flue gas waste heat recovery comprehensive utilization single-channel pure dry dedusting system of claim 4, further comprising:

7. The converter flue gas waste heat recovery comprehensive utilization single-channel pure dry dedusting system of claim 1, wherein each group of evaporators is provided with 2 groups of sound wave soot blowers capable of reciprocating.

8. The converter flue gas waste heat recovery comprehensive utilization single-channel pure dry dedusting system of claim 1, characterized in that,

and the boiler pipe of the waste heat boiler adopts a pre-spraying measure to spray a special ceramic or metal ceramic coating on the surface of the boiler pipeline.

9. The converter flue gas waste heat recovery comprehensive utilization single-channel pure dry dedusting system of claim 1, wherein the dry box body adopts a bag-type dust remover.

10. The converter flue gas waste heat recovery comprehensive utilization single-channel pure dry dedusting system of claim 3, wherein the fan subsystem is configured as two coal gas induced fans.