CN107893143B - Converter gas dry dedusting waste heat recovery system and process - Google Patents

Abstract

The invention discloses a converter gas dry dedusting waste heat recovery system and a converter gas dry dedusting waste heat recovery process, wherein the converter gas dry dedusting waste heat recovery system comprises a flue gas filter (3), a chemical-looping combustion device (6) and a waste heat boiler (7), the chemical-looping combustion device (6) comprises a chemical-looping combustion reaction device (600), an outlet of the flue gas filter (3) is connected with an inlet of the chemical-looping combustion reaction device (600) through a first exhaust pipeline (611), an outlet of the chemical-looping combustion reaction device (600) is connected with a first inlet of the waste heat boiler (7) through a second exhaust pipeline (612), and the chemical-looping combustion reaction device (600) is connected with a recovery pipeline (621) in parallel. The system and the process for recovering the waste heat of the dry dedusting of the converter gas can realize the recovery of sensible heat energy of the converter gas at the temperature of below 900 ℃, realize zero emission of the converter gas, do not need to arrange an explosion venting valve, and can discontinuously treat the converter gas to realize continuous energy supply.

Description

A converter gas dry dust removal waste heat recovery system and process

technical field

The invention relates to the technical field of flue gas recovery and utilization, in particular to a converter gas dry dedusting waste heat recovery system and a converter gas dry purification waste heat recovery process.

Background technique

Generally, the converter steelmaking cycle is 36 minutes, and the oxygen blowing time is 15 minutes. During this process, a large amount of high-temperature and high-dust flue gas will be generated. The flue gas temperature is 1500 ° C ~ 1600 ° C, and the main components of dust are FeO, Fe ₂ O ₃ , CaO and SiO ₂ etc., the dust content can reach 80g/m ³ ~ 150g/m ³ .

Due to the intermittent generation of converter gas and the characteristics of high temperature and high dust content, it is difficult to remove dust and recover waste heat from converter gas. In terms of dedusting, the existing converter gas dedusting technology is mainly divided into wet dedusting system and dry dedusting system.

The wet dedusting system is mainly composed of flue gas cooling, purification, gas recovery and sewage treatment. The wet dust removal system has the following disadvantages: 1. The dust removal efficiency is low, and the gas content after treatment is about 50-100 mg/Nm ³ ; 2. The system has large resistance loss and high operating costs; 3. There is secondary pollution and a large amount of sewage It needs to be dealt with; 4. It occupies a large area. The dry dust removal system is mainly composed of gasification cooling flue, steam generator, electrostatic precipitator, etc. Compared with the wet dust removal system, it has obvious advantages. 1. The dust removal efficiency is high, and the dust content of the flue gas can be reduced to 5-15 mg/Nm3; 2. The system resistance loss is small, and the operating cost is low; 3. There is no secondary pollution, no sewage generation, and the recovered dust can be directly used; 4. Small footprint, easy to manage and maintain. The main disadvantage of the dry dust removal system is that there is a hidden danger of explosion, and an explosion relief valve needs to be installed, and a large explosion may exceed the tolerance range of the explosion relief valve of the electrostatic precipitator and blow up the electrostatic precipitator.

In terms of waste heat recovery, neither the wet dust removal system nor the dry dust removal system has been effectively recovered. Especially for the sensible heat energy below 900°C of the converter gas output through the gasification cooling flue. The dry dust removal waste heat recovery system of the ceramic filter can solve this problem. The converter gas output from the gasification cooling flue enters the ceramic filter for dust removal, and the converter gas after dust removal and purification enters the waste heat boiler to utilize its sensible heat. However, because the generation of converter gas is periodic, the ceramic filter dry dedusting system and waste heat boiler system can only be used intermittently, that is, when converter gas is generated during the oxygen blowing cycle of the converter, the continuity of energy supply cannot be guaranteed. At the same time, when the _O2 and CO content of the converter gas does not meet the recovery requirements, it needs to be released, and the chemical energy of this part of the converter gas cannot be utilized, which will also cause environmental pollution.

Glossary:

Oxygen carrier: In the chemical chain combustion reaction, the solid oxide used to transfer oxygen is called oxygen carrier. There are mainly Cu-based, Ni-based, Fe-based, Ca-based and other oxygen carriers. Taking the Cu-based oxygen carrier as an example, CuO is generally used as the active component, and Al ₂ O ₃ , SiO ₂ , etc. are used as the inert carrier for preparation.

Contents of the invention

In order to solve the problem of discontinuity of energy supply above, the present invention provides a waste heat recovery system and process of converter gas dry dust removal, which can realize the recovery of sensible heat energy of converter gas at a temperature below 900°C , to achieve zero emission of converter gas, no need to set up explosion relief valves, and can process converter gas intermittently to achieve continuous energy supply.

The technical solution adopted by the present invention to solve the technical problem is: a converter gas dry dust removal waste heat recovery system, including a flue gas filter, chemical looping combustion equipment and waste heat boiler, chemical looping combustion equipment contains chemical looping combustion reaction device, smoke The outlet of the gas filter is connected to the inlet of the chemical looping combustion reaction device through the first exhaust pipe, the outlet of the chemical looping combustion reaction device is connected to the first inlet of the waste heat boiler through the second exhaust pipe, and the flue gas filter and the waste heat boiler There is also a recovery pipeline between them, and the recovery pipeline is arranged in parallel with the chemical looping combustion reaction device.

The first exhaust pipe is provided with a three-way valve, the three-way valve has an inlet and two outlets, the inlet of the recovery pipe is connected to one outlet of the three-way valve, and the outlet of the recovery pipe is connected to the second inlet of the waste heat boiler.

There is also a flue gas analyzer on the first exhaust pipe, the flue gas analyzer is located between the flue gas filter and the three-way valve, and the inlet end of the flue gas filter is connected with a gasification cooling device capable of cooling the flue gas flue.

The gasification cooling flue is connected with an energy storage device, which can store the heat of the flue gas in the gasification cooling flue, and the gasification cooling flue is equipped with an ultrasonic cleaning device, and the flue gas filter is a ceramic flue gas filter , The chemical looping combustion reaction device is equipped with a cooling water jacket.

The chemical looping combustion equipment also includes a third exhaust pipe and a fourth exhaust pipe, the inlet of the third exhaust pipe is connected with an air fan, the outlet of the third exhaust pipe is connected with the outlet of the chemical looping combustion reaction device, and the fourth row The inlet of the gas pipe is connected with the inlet of the chemical looping combustion reaction device, and the outlet of the fourth exhaust pipe is connected with the first inlet of the waste heat boiler.

The first exhaust pipe is provided with a first valve, the second exhaust pipe is provided with a second valve, the third exhaust pipe is provided with a third valve, and the fourth exhaust pipe is provided with a fourth valve.

The converter gas dry dedusting waste heat recovery system also includes a gas cooler, a gas cabinet and a release tower. The first outlet of the waste heat boiler is connected to the release tower through the first exhaust pipe, and the second outlet of the waste heat boiler is connected through the second exhaust pipe. The pipeline is connected with the inlet of the gas cooler, and the outlet of the gas cooler is connected with the inlet of the gas cabinet through the third exhaust pipe.

A converter gas dry purification waste heat recovery process. The converter gas dry purification waste heat recovery process is carried out simultaneously with the converter steelmaking cycle. The converter steelmaking cycle includes a preparation stage, a blowing stage and a tapping stage arranged in sequence. The converter gas dry purification waste heat recovery process adopts the above-mentioned converter gas dry dust removal waste heat recovery system, and the converter gas dry purification waste heat recovery process includes the following steps:

Step 1. In the preparatory stage, the first exhaust pipe between the inlet end of the recovery pipe and the entrance of the chemical looping combustion reaction device is closed;

Step 2. In the blowing stage, judge whether the flue gas discharged from the flue gas filter meets the recovery standard. When the recovery standard can be reached, the flue gas discharged from the flue gas filter enters the waste heat boiler only through the recovery pipe; when the recovery standard cannot be reached, The flue gas discharged from the flue gas filter only enters the chemical looping combustion reaction device through the first exhaust pipe and undergoes a reduction reaction, and the chemical looping combustion reaction device discharges the reduction gas product into the waste heat boiler through the second exhaust pipe;

Step 3. In the tapping stage, the first exhaust pipe between the inlet end of the recovery pipe and the entrance of the chemical looping combustion reaction device is closed.

In steps 1 and 3, air is blown into the chemical looping combustion reaction device from the outlet of the chemical looping combustion reaction device. The inlet discharges and enters the waste heat boiler.

The recovery standard is that the volume fraction of CO in the converter gas is ≥ 35% and the volume fraction of O ≤ ₂ %; in step 2, when the recovery standard can be reached, the gas discharged from the waste heat boiler enters the gas cooler and the gas cabinet in sequence; when When the recovery standard cannot be reached, the gas discharged from the waste heat boiler enters the dissipation tower; in steps 1 and 3, the gas discharged from the waste heat boiler enters the dissipation tower.

The beneficial effects of the present invention are: the converter gas dry dedusting waste heat recovery system and process adopts a chemical chain combustion reaction device, which can process the converter gas whose components do not meet the recovery standard, and adopts ceramic filters to efficiently remove the converter gas in the dust. This system and process can recover the sensible heat energy of converter gas below 900°C and the chemical energy of released gas. It is a new dry dust removal waste heat recovery system with high dust removal efficiency, low operating energy consumption, full heat recovery of gas and zero discharge of gas. craft.

Description of drawings

The accompanying drawings constituting a part of the present application are used to provide a further understanding of the present invention, and the schematic embodiments and descriptions of the present invention are used to explain the present invention, and do not constitute an improper limitation of the present invention.

Fig. 1 is a schematic structural view of the waste heat recovery system for converter gas dry dedusting according to the present invention.

Figure 2 is a schematic diagram of the internal piping structure of the waste heat boiler.

1. Converter; 2. Gasification cooling flue; 3. Flue gas filter; 4. Flue gas analyzer; 5. Three-way valve; 6. Chemical chain combustion equipment; 7. Waste heat boiler; 8. Gas cooler; 9. Gas cabinet; 10. Diffuser tower;

501, the first solenoid valve; 502, the second solenoid valve;

600, chemical looping combustion reaction device; 601, first valve; 602, second valve; 603, third valve; 604, fourth valve; 605, air blower; 606, cooling water jacket;

611, the first exhaust pipe; 612, the second exhaust pipe; 613, the third exhaust pipe; 614, the fourth exhaust pipe;

621. Recovery pipeline;

701, the first smoke exhaust pipe; 702, the second smoke exhaust pipe; 703, the third smoke exhaust pipe.

detailed description

It should be noted that, in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and examples.

A converter gas dry dedusting waste heat recovery system, including a flue gas filter 3, chemical looping combustion equipment 6 and waste heat boiler 7, the chemical looping combustion equipment 6 contains a chemical looping combustion reaction device 600, the outlet of the flue gas filter 3 passes through the first An exhaust pipe 611 is connected to the inlet of the chemical looping combustion reaction device 600, the outlet of the chemical looping combustion reaction device 600 is connected to the first inlet of the waste heat boiler 7 through the second exhaust pipe 612, the flue gas filter 3 and the waste heat boiler 7 There is also a recovery pipeline 621 between them, and the recovery pipeline 621 is arranged in parallel with the chemical looping combustion reaction device 600 , as shown in FIG. 1 .

In this embodiment, the first exhaust pipe 611 is provided with a three-way valve 5, the three-way valve 5 has an inlet and two outlets, the inlet end of the recovery pipe 621 is connected to an outlet of the three-way valve 5, and the three-way valve One outlet of 5 is provided with a second electromagnetic valve 502, the outlet end of the recovery pipe 621 is connected to the second inlet of the waste heat boiler 7, the inlet of the chemical looping combustion reaction device 600 can be connected with the other outlet of the three-way valve 5, and the three-way The other outlet of the valve 5 is provided with a first solenoid valve 501 , and the outlet of the smoke filter 3 can communicate with the inlet of the three-way valve 5 . The first exhaust pipe 611 is also provided with a flue gas analyzer 4, the flue gas analyzer 4 is located between the flue gas filter 3 and the three-way valve 5, and the flue gas analyzer 4 can analyze the exhaust gas from the flue gas filter 3. Composition and content of the flue gas, the inlet end of the flue gas filter 3 is connected with a gasification cooling flue 2 capable of cooling the flue gas.

In this embodiment, the inlet end of the gasification cooling flue 2 is located above the converter 1, and a cooling water pipe is arranged in the gasification cooling flue 2, and the converter gas first enters the gasification cooling flue 2, and the converter gas and the flue The pipe wall exchanges heat indirectly through the cooling water. The cooling water pipe of the gasification cooling flue 2 is connected with an energy storage device, which is also connected with the waste heat boiler 7. The energy storage device can store the smoke in the gasification cooling flue 2. The energy storage device can store the heat absorbed by the waste heat boiler 7. The gasification cooling flue 2 is also equipped with an ultrasonic soot cleaning device, the flue gas filter 3 is a ceramic flue gas filter, and the chemical looping combustion reaction device 600 is equipped with a cooling water jacket 606 .

The waste heat boiler 7 has two inlets and two outlets. The first inlet of the waste heat boiler 7 is only connected to the first outlet of the waste heat boiler 7 through the first inner pipe, and the second inlet of the waste heat boiler 7 is only connected to the waste heat boiler through the second inner pipe. The second outlet of the boiler 7 is connected, that is, the fluid entering from the first inlet of the waste heat boiler 7 can only be discharged from the first outlet of the waste heat boiler 7 and cannot be discharged from the second outlet of the waste heat boiler 7. The fluid entering the inlet can only be discharged from the second outlet of the waste heat boiler 7 and cannot be discharged from the first outlet of the waste heat boiler 7, as shown in FIG. 2 . When the converter gas reaches the recovery standard, it goes directly through the recovery pipeline 621 without going through the chemical looping combustion reactor, enters the waste heat boiler 7 for heat recovery, passes through the second smoke exhaust pipeline 702, and then enters the gas cooler 8 and the gas cabinet 9 to store the gas. When the recovery standard is not met, it enters the waste heat boiler 7 through the chemical looping combustion reactor through the second exhaust pipe 612 , and after recycling the waste heat, it enters the emission tower 10 through the first smoke exhaust pipe 701 for discharge.

In the present embodiment, the chemical looping combustion equipment 6 also contains a third exhaust pipeline 613 and a fourth exhaust pipeline 614, the inlet of the third exhaust pipeline 613 is connected with an air blower 605, and the outlet of the third exhaust pipeline 613 is connected with The outlet of the chemical looping combustion reaction device 600 is connected, the inlet of the fourth exhaust pipe 614 is connected with the inlet of the chemical looping combustion reaction device 600, and the outlet of the fourth exhaust pipe 614 is connected with the first inlet of the waste heat boiler 7, as shown in Figure 1 shown. The first exhaust pipe 611 is provided with a first valve 601, the second exhaust pipe 612 is provided with a second valve 602, the third exhaust pipe 613 is provided with a third valve 603, and the fourth exhaust pipe 614 is provided with There is a fourth valve 604 . The first valve 601 , the second valve 602 , the third valve 603 and the fourth valve 604 are all electromagnetic valves.

In this embodiment, the converter gas dry dedusting waste heat recovery system also includes a gas cooler 8, a gas cabinet 9 and a dissipation tower 10, and the first outlet of the waste heat boiler 7 is connected to the dissipation tower 10 through a first exhaust pipe 701 , the second outlet of the waste heat boiler 7 is connected to the inlet of the gas cooler 8 through the second exhaust pipe 702, and the outlet of the gas cooler 8 is connected to the inlet of the gas cabinet 9 through the third exhaust pipe 703, as shown in Figure 1 .

The working process of each device in the converter gas dry dedusting waste heat recovery system of the present invention will be introduced below.

During converter steelmaking, a large amount of converter gas will be produced by blowing oxygen into converter 1 for decarburization.

When the converter gas passes through the gasification cooling flue 2, the converter gas exchanges heat with the cooling water in the flue, and at the same time the cooling water absorbs heat and evaporates into saturated steam; the saturated steam and waste heat generated by the gasification cooling flue 2 The water vapor produced by the boiler 7 is output to the steam energy storage device.

The converter gas output from the gasification cooling flue 2 enters the flue gas filter 3 (ceramic filter) for dust removal; the dust collected by the flue gas filter 3 is sent to the briquetting station by a conveyor, and the dust is removed by hot pressing Forming, the obtained powder blocks are used for converter steelmaking. The ceramic filter dedusts the dust-laden converter gas through sieving, and when the outer surface of the ceramic filter has too much dust and the dust removal resistance is too large, it is blown back to remove dust.

After the converter gas enters the waste heat boiler 7, it exchanges heat indirectly with the water in the waste heat boiler 7, and at the same time, the water in the waste heat boiler 7 absorbs heat to form water vapor.

After being cooled by the waste heat boiler, the converter gas enters the gas cooler 8 for further cooling and then enters the gas cabinet 9 for storage. Or the converter gas enters the release tower 10 for release after being cooled by the waste heat boiler.

The chemical looping combustion reaction device 600 is filled with metal oxygen carriers. The metal oxygen carrier is one or a mixture of Cu-based oxygen carrier or Fe-based oxygen carrier. The metal oxygen carrier as described can be a mixture of an Fe-based oxygen carrier with _Fe2O3 as the main component and a Cu-based oxygen carrier with _CuO as the main component; the mass of the Cu-based oxygen carrier accounts for 5% to 20% of the total mass of the metal oxygen carrier. A cooling water jacket 606 is arranged inside the outer shell of the chemical looping combustion reaction device 600 .

The metal oxygen carrier based on Fe-based oxygen carrier has a large adiabatic reaction temperature rise in the oxidation reaction. In the present invention, a cooling water jacket 606 is added to the chemical looping combustion reaction device to stabilize the reactor temperature. In order to avoid damage to the metal oxygen carrier due to temperature surge.

Each device in the converter gas dry dedusting waste heat recovery system of the present invention can adopt existing devices, such as chemical looping combustion reaction device 600, gasification cooling flue 2, ultrasonic cleaning device, cooling water jacket 606 and Energy storage devices, etc.

The following is a waste heat recovery process of converter gas dry purification.

The converter gas dry purification waste heat recovery process is carried out simultaneously with the converter steelmaking cycle, and the converter steelmaking cycle includes a preparation stage, a blowing stage and a steel tapping stage arranged in sequence, and a converter gas dry purification waste heat recovery process is combined with the The three stages of the converter steelmaking cycle correspond one by one. The converter gas dry purification waste heat recovery process adopts the above-mentioned converter gas dry dust removal waste heat recovery system. The converter gas dry purification waste heat recovery process includes the following steps:

Step 1. In the preparation stage, the first exhaust pipe 611 between the inlet end of the recovery pipe 621 and the entrance of the chemical looping combustion reaction device 600 is closed;

Step 2. In the blowing stage, judge whether the flue gas discharged from the flue gas filter 3 reaches the recovery standard. When the recovery standard can be reached, the flue gas discharged from the flue gas filter 3 enters the waste heat boiler 7 only through the recovery pipe 621; When the recovery standard is reached, the flue gas discharged from the flue gas filter 3 only enters the chemical looping combustion reaction device 600 through the first exhaust pipe 611 and undergoes a reduction reaction, and the chemical looping combustion reaction device 600 passes the reducing gas through the second exhaust pipe 612 The product is discharged into the waste heat boiler 7;

Step 3. In the tapping stage, the first exhaust pipe 611 located between the inlet end of the recovery pipe 621 and the inlet of the chemical looping combustion reaction device 600 is closed.

In steps 1 and 3, air is blown into the chemical looping combustion reaction device 600 from the outlet of the chemical looping combustion reaction device 600, and the air is oxidized in the chemical looping combustion reaction device 600. The inlet of the combustion reaction device 600 is exhausted and enters the waste heat boiler 7 . The converter gas dry purification waste heat recovery process can realize the recovery of the sensible heat energy of the converter gas at a temperature below 900°C, realize zero emission of the converter gas, and eliminate the need for an explosion relief valve, and can process the converter gas intermittently to achieve continuous energy supply.

Since a converter gas dry purification waste heat recovery process corresponds to the three stages of the converter steelmaking cycle, as the converter steelmaking cycle goes back and forth, the converter gas dry purification waste heat recovery process will also cycle accordingly back and forth.

The waste heat recovery process of converter gas dry purification according to the present invention will be described in detail below by taking the converter steelmaking cycle as 36 minutes as an example.

Assuming that the converter steelmaking cycle is 36min, of which 0min-10min is the preparatory stage of blowing, 10min-26min is the blowing stage, 12min-24min is the gas recovery stage, and 26min-36min is the tapping stage, then the converter gas dry Purification waste heat recovery process is as follows:

Step 1. In the preparation stage, corresponding to 0-10 minutes in the steelmaking cycle of 36 minutes, no converter gas is generated, the chemical looping combustion reaction device 600 is switched to the oxidation reaction process, the first solenoid valve 501 is closed, the first valve 601 and the second The valve 602 is closed, the third valve 603 and the fourth valve 604 are opened, and at the same time, the air blower 605 is opened. At this point, an oxidation reaction takes place in the chemical looping combustion reaction device 600:

Cu+1/2O ₂ ＝CuO△H＝-35.971kcal/mol

2Fe ₃ O ₄ +1/2O ₂ ＝3Fe ₂ O ₃ △H＝-57.776kcal/mol

2FeO+1/2O ₂ ＝Fe ₂ O ₃ △H＝-66.403kcal/mol

The temperature of the oxidation reaction is 900°C-1000°C, the oxidation gas product is _N2 and enters the waste heat boiler 7, in the waste heat boiler 7, the oxidation gas product exchanges heat indirectly with water, the temperature of the converter gas is reduced to 150°C-200°C, and the water After absorbing heat, it turns into water vapor and enters the steam bag. Oxidation gas products are evacuated through the vent tower 10 .

Step 2. In the blowing stage, corresponding to 10-26 minutes in the steelmaking cycle of 36 minutes, a large amount of converter gas is generated by blowing oxygen in the converter 1 for decarburization, and the temperature of the output converter gas is about 1500 ° C. The high-temperature dust-containing converter gas First enter the gasification cooling flue 2, the converter gas and the pipe wall of the flue exchange heat indirectly through the cooling water, the gas temperature drops from 1500°C to 900°C, and the cooling water absorbs heat and evaporates into saturated steam. Converter gas at 900°C enters flue gas filter 3 for dust removal.

Whether the converter gas after the dust removal by the ceramic filter reaches the recovery standard is judged by the flue gas analyzer 4, if the recovery standard is reached (such as the volume fraction or mole fraction of CO in the converter gas≥35% and the volume fraction or mole fraction of O2≤2 %), generally 12-24 minutes in the steelmaking cycle of 36 minutes, that is, the gas recovery stage, the second solenoid valve 502 on the recovery side of the three-way valve 5 is opened, the first solenoid valve 501 on the release side is closed, and the flue gas is filtered The converter gas discharged from the device 3 directly enters the waste heat boiler 7 through the recovery pipeline 621. In the waste heat boiler 7, the converter gas and water exchange heat indirectly, and the temperature of the converter gas further decreases to 150°C-200°C, and the water absorbs heat and becomes water. The steam goes into the steam bag. Afterwards, the converter gas enters the gas cooler 8 to lower the converter gas from 150°C to 200°C to 70°C, and then enters the gas cabinet 9 for storage.

If the converter gas discharged through the flue gas filter 3 cannot meet the recovery standard (such as the volume fraction of CO in the converter gas ≥ 35% or the volume fraction of O2 ≤ 2%), generally within the first 2 minutes and the last 2 minutes of the blowing stage At this time, the second solenoid valve 502 on the recovery side of the three-way valve 5 is closed, the first solenoid valve 501 on the release side is opened, the first valve 601 and the second valve 602 are opened, and the third valve 603 and the fourth valve 604 are closed. , the converter gas enters the chemical looping combustion reaction device 600 . In the chemical looping combustion reaction device 600, the converter gas and the metal oxide undergo a reduction reaction:

3Fe ₂ O ₃ +CO＝2Fe ₃ O ₄ +CO ₂ △H＝-9.768kcal/mol

Fe ₂ O ₃ +CO=2FeO+CO ₂ △H=-1.163kcal/mol

CuO+CO=Cu+CO ₂ △H=-31.595kcal/mol

The reduction reaction temperature is 900°C-1000°C, the reduction gas product CO ₂ enters the waste heat boiler 7, in the waste heat boiler 7, the reduction gas product and water indirect heat exchange, the converter gas temperature is further reduced to 150°C-200°C, the water absorbs After heating, it turns into water vapor and enters the steam bag. The reducing gas products are evacuated through the vent column 10 .

Step 3. In the tapping stage, corresponding to 26-36 minutes of the 36-minute steelmaking cycle, when no converter gas is produced, the chemical looping combustion reaction device 600 switches to the oxidation reaction process, the first solenoid valve 501 is closed, the first valve 601 and the second The second valve 602 is closed, the third valve 603 and the fourth valve 604 are opened, and at the same time, the air blower 605 is opened. At this point, an oxidation reaction takes place in the chemical looping combustion reaction device 600:

Cu+1/2O ₂ ＝CuO△H＝-35.971kcal/mol

2Fe ₃ O ₄ +1/2O ₂ ＝3Fe ₂ O ₃ △H＝-57.776kcal/mol

2FeO+1/2O ₂ ＝Fe ₂ O ₃ △H＝-66.403kcal/mol

The oxidation reaction temperature is 900°C-1000°C, the oxidizing gas product is _N2 and enters the waste heat boiler 7, in the waste heat boiler 7, the oxidizing gas product exchanges heat indirectly with water, the temperature of the converter gas is reduced to 150°C-200°C, and the water absorbs heat Then it turns into water vapor and enters the steam bag. Oxidation gas products are evacuated through the vent tower 10 .

Among them, the gasification cooling flue 2 is equipped with an ultrasonic cleaning device to remove dust on the inner wall, improve the heat transfer coefficient of gas-water, and increase the amount of steam recovery. The saturated steam generated by the gasification cooling flue 2 and the water vapor generated by the waste heat boiler are output to the steam energy storage device, which can be used for steelmaking process and heating.

The flue gas filter 3 can be a ceramic filter, which belongs to a high-temperature dust collector. The ceramic filter adopts a pulse cleaning method, and the dust removal efficiency reaches 99.9%. The ceramic filter mainly removes dust from the dusty gas by screening . When there is too much dust on the outer surface of the ceramic filter and the dust removal resistance is too large, it needs to be blown back to clean the dust. The ceramic filter adopts the pulse cleaning method, and the gas source is high temperature and high pressure nitrogen. The dust collected by the ceramic filter is sent to the briquetting station by the conveyor, and the dust is pressed into shape by hot briquetting, and the formed powder briquette can be directly used for converter steelmaking.

In addition, if there are any details, please refer to the Chinese patent CN 104388627A, published on March 4, 2015, "A Converter Gas Dust Removal Method and System".

The above is only a specific embodiment of the present invention, and cannot limit the scope of the invention, so the replacement of its equivalent components, or the equivalent changes and modifications made according to the patent protection scope of the present invention, should still fall within the scope of this patent. category. In addition, the technical features and technical features, technical features and technical solutions, and technical solutions and technical solutions in the present invention can be used in free combination.

Claims (7)

1. The converter gas dry dedusting waste heat recovery system is characterized by comprising a flue gas filter (3), a chemical looping combustion device (6) and a waste heat boiler (7), wherein the chemical looping combustion device (6) comprises a chemical looping combustion reaction device (600), an outlet of the flue gas filter (3) is connected with an inlet of the chemical looping combustion reaction device (600) through a first exhaust pipeline (611), an outlet of the chemical looping combustion reaction device (600) is connected with a first inlet of the waste heat boiler (7) through a second exhaust pipeline (612), a recovery pipeline (621) is further arranged between the flue gas filter (3) and the waste heat boiler (7), and the recovery pipeline (621) is connected with the chemical looping combustion reaction device (600) in parallel;

a three-way valve (5) is arranged on the first exhaust pipeline (611), the three-way valve (5) comprises an inlet and two outlets, the inlet end of the recovery pipeline (621) is connected with one outlet of the three-way valve (5), and the outlet end of the recovery pipeline (621) is connected with a second inlet of the waste heat boiler (7);

the chemical looping combustion device (6) further comprises a third exhaust pipeline (613) and a fourth exhaust pipeline (614), an inlet of the third exhaust pipeline (613) is connected with an air fan (605), an outlet of the third exhaust pipeline (613) is connected with an outlet of the chemical looping combustion reaction device (600), an inlet of the fourth exhaust pipeline (614) is connected with an inlet of the chemical looping combustion reaction device (600), and an outlet of the fourth exhaust pipeline (614) is connected with a first inlet of the waste heat boiler (7).

2. The system for recovering the waste heat in the dry dedusting of the converter gas according to the claim 1, characterized in that a flue gas analyzer (4) is further arranged on the first exhaust duct (611), the flue gas analyzer (4) is located between the flue gas filter (3) and the three-way valve (5), and a gasification cooling flue (2) capable of cooling the flue gas is connected to the outside of the inlet end of the flue gas filter (3).

3. The converter gas dry dedusting waste heat recovery system according to claim 2, characterized in that the gasification cooling flue (2) is connected with an energy storage device, the energy storage device can store the heat of the flue gas in the gasification cooling flue (2), an ultrasonic ash removal device is arranged in the gasification cooling flue (2), the flue gas filter (3) is a ceramic flue gas filter, and a cooling water jacket (606) is arranged outside the chemical looping combustion reaction device (600).

4. The system for recovering the waste heat of the dry dedusting of the converter gas according to the claim 1, wherein a first valve (601) is arranged on the first exhaust pipeline (611), a second valve (602) is arranged on the second exhaust pipeline (612), a third valve (603) is arranged on the third exhaust pipeline (613), and a fourth valve (604) is arranged on the fourth exhaust pipeline (614).

5. The converter gas dry dedusting waste heat recovery system according to claim 1, further comprising a gas cooler (8), a gas holder (9) and a diffusing tower (10), wherein a first outlet of the waste heat boiler (7) is connected with the diffusing tower (10) through a first smoke exhaust pipeline (701), a second outlet of the waste heat boiler (7) is connected with an inlet of the gas cooler (8) through a second smoke exhaust pipeline (702), and an outlet of the gas cooler (8) is connected with an inlet of the gas holder (9) through a third smoke exhaust pipeline (703).

6. A converter gas dry purification waste heat recovery process is characterized in that the converter gas dry purification waste heat recovery process and a converter steelmaking cycle are carried out simultaneously, the converter steelmaking cycle comprises a preparation stage, a blowing stage and a tapping stage which are sequentially arranged, the converter gas dry purification waste heat recovery process adopts the converter gas dry dedusting waste heat recovery system of any one of claims 1 to 5, and the converter gas dry purification waste heat recovery process comprises the following steps:

step 1, in a preparation stage, enabling a first exhaust pipeline (611) between an inlet end of a recovery pipeline (621) and an inlet of a chemical-looping combustion reaction device (600) to be in a closed state;

step 2, in the converting stage, judging whether the flue gas discharged by the flue gas filter (3) meets the recovery standard, and when the flue gas discharged by the flue gas filter (3) can meet the recovery standard, only entering a waste heat boiler (7) through a recovery pipeline (621); when the recovery standard cannot be met, the flue gas discharged by the flue gas filter (3) enters the chemical looping combustion reaction device (600) through the first exhaust pipeline (611) and is subjected to reduction reaction, and the chemical looping combustion reaction device (600) discharges the reduction gas products into the waste heat boiler (7) through the second exhaust pipeline (612);

step 3, in the steel tapping stage, enabling a first exhaust pipeline (611) between the inlet end of the recovery pipeline (621) and the inlet of the chemical-looping combustion reaction device (600) to be in a closed state;

in the steps 1 and 3, air is blown into the chemical looping combustion reaction device (600) from the outlet of the chemical looping combustion reaction device (600), the air is subjected to oxidation reaction in the chemical looping combustion reaction device (600), and the oxidation gas product is discharged from the inlet of the chemical looping combustion reaction device (600) and enters the waste heat boiler (7).

7. The process for recovering the waste heat by dry purification of the converter gas as claimed in claim 6, wherein the recovery standard is that the volume fraction of CO in the converter gas is not less than 35% and O is ₂ The volume fraction is less than or equal to 2 percent;

in step 2, when the recovery standard can be met, the gas discharged by the waste heat boiler (7) enters a gas cooler (8) and a gas holder (9) in sequence; when the recovery standard can not be met, the gas discharged from the waste heat boiler (7) enters a diffusing tower (10);

in the step 1 and the step 3, the gas discharged by the waste heat boiler (7) enters a diffusing tower (10).

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