CN113188335B - Chain grate rotary kiln hot air system suitable for active coke desulfurization and denitrification process - Google Patents
Chain grate rotary kiln hot air system suitable for active coke desulfurization and denitrification process Download PDFInfo
- Publication number
- CN113188335B CN113188335B CN202110434236.6A CN202110434236A CN113188335B CN 113188335 B CN113188335 B CN 113188335B CN 202110434236 A CN202110434236 A CN 202110434236A CN 113188335 B CN113188335 B CN 113188335B
- Authority
- CN
- China
- Prior art keywords
- hot air
- section
- preheating
- drying
- pipeline
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000006477 desulfuration reaction Methods 0.000 title claims abstract description 39
- 230000023556 desulfurization Effects 0.000 title claims abstract description 39
- 239000000571 coke Substances 0.000 title claims abstract description 35
- 238000000034 method Methods 0.000 title claims description 44
- 230000008569 process Effects 0.000 title claims description 41
- 238000001035 drying Methods 0.000 claims abstract description 110
- 239000008188 pellet Substances 0.000 claims abstract description 52
- 238000007664 blowing Methods 0.000 claims abstract description 16
- 239000007789 gas Substances 0.000 claims description 17
- 238000007605 air drying Methods 0.000 claims description 11
- 239000000428 dust Substances 0.000 claims description 9
- 230000001105 regulatory effect Effects 0.000 claims description 4
- 238000009423 ventilation Methods 0.000 claims description 4
- 239000002912 waste gas Substances 0.000 claims description 4
- 238000005516 engineering process Methods 0.000 abstract 1
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 24
- 239000003546 flue gas Substances 0.000 description 24
- RAHZWNYVWXNFOC-UHFFFAOYSA-N Sulphur dioxide Chemical compound O=S=O RAHZWNYVWXNFOC-UHFFFAOYSA-N 0.000 description 16
- MWUXSHHQAYIFBG-UHFFFAOYSA-N Nitric oxide Chemical compound O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 15
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 13
- IXCSERBJSXMMFS-UHFFFAOYSA-N hydrogen chloride Substances Cl.Cl IXCSERBJSXMMFS-UHFFFAOYSA-N 0.000 description 13
- 229910000041 hydrogen chloride Inorganic materials 0.000 description 13
- 238000005192 partition Methods 0.000 description 10
- 230000000694 effects Effects 0.000 description 8
- 235000010269 sulphur dioxide Nutrition 0.000 description 8
- 238000004519 manufacturing process Methods 0.000 description 7
- 238000010276 construction Methods 0.000 description 5
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 4
- 230000009471 action Effects 0.000 description 4
- 238000001816 cooling Methods 0.000 description 4
- 230000007797 corrosion Effects 0.000 description 4
- 238000005260 corrosion Methods 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 229910000831 Steel Inorganic materials 0.000 description 3
- 239000000460 chlorine Substances 0.000 description 3
- 239000013078 crystal Substances 0.000 description 3
- 239000010959 steel Substances 0.000 description 3
- 239000011593 sulfur Substances 0.000 description 3
- 229910052717 sulfur Inorganic materials 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- NLXLAEXVIDQMFP-UHFFFAOYSA-N Ammonia chloride Chemical compound [NH4+].[Cl-] NLXLAEXVIDQMFP-UHFFFAOYSA-N 0.000 description 2
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- WCUXLLCKKVVCTQ-UHFFFAOYSA-M Potassium chloride Chemical compound [Cl-].[K+] WCUXLLCKKVVCTQ-UHFFFAOYSA-M 0.000 description 2
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 229910021529 ammonia Inorganic materials 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 229910052801 chlorine Inorganic materials 0.000 description 2
- 230000018044 dehydration Effects 0.000 description 2
- 238000006297 dehydration reaction Methods 0.000 description 2
- 238000004134 energy conservation Methods 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 230000007246 mechanism Effects 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 239000011819 refractory material Substances 0.000 description 2
- 150000003839 salts Chemical class 0.000 description 2
- 230000001502 supplementing effect Effects 0.000 description 2
- 230000007704 transition Effects 0.000 description 2
- 239000002699 waste material Substances 0.000 description 2
- 230000006978 adaptation Effects 0.000 description 1
- 235000019270 ammonium chloride Nutrition 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 229910052500 inorganic mineral Inorganic materials 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 239000011707 mineral Substances 0.000 description 1
- 235000010755 mineral Nutrition 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 239000001103 potassium chloride Substances 0.000 description 1
- 235000011164 potassium chloride Nutrition 0.000 description 1
- 230000001172 regenerating effect Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 239000004291 sulphur dioxide Substances 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
- F27B21/00—Open or uncovered sintering apparatus; Other heat-treatment apparatus of like construction
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/02—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by adsorption, e.g. preparative gas chromatography
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
- F27D15/00—Handling or treating discharged material; Supports or receiving chambers therefor
- F27D15/02—Cooling
- F27D15/0206—Cooling with means to convey the charge
- F27D15/0213—Cooling with means to convey the charge comprising a cooling grate
- F27D15/022—Cooling with means to convey the charge comprising a cooling grate grate plates
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
- F27D17/00—Arrangements for using waste heat; Arrangements for using, or disposing of, waste gases
- F27D17/004—Systems for reclaiming waste heat
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
- F27D17/00—Arrangements for using waste heat; Arrangements for using, or disposing of, waste gases
- F27D17/008—Arrangements for using waste heat; Arrangements for using, or disposing of, waste gases cleaning gases
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2253/00—Adsorbents used in seperation treatment of gases and vapours
- B01D2253/10—Inorganic adsorbents
- B01D2253/102—Carbon
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2257/00—Components to be removed
- B01D2257/30—Sulfur compounds
- B01D2257/302—Sulfur oxides
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2257/00—Components to be removed
- B01D2257/40—Nitrogen compounds
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2258/00—Sources of waste gases
- B01D2258/02—Other waste gases
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2258/00—Sources of waste gases
- B01D2258/02—Other waste gases
- B01D2258/025—Other waste gases from metallurgy plants
Abstract
The application discloses be suitable for chain grate machine rotary kiln hot air system of active burnt SOx/NOx control technology includes: the drying grate comprises a drying blowing section (UDD), an air draft drying section (DDD), a preheating I section (TPH), a preheating II section (PH), a first annular cooler section (C1) and a second annular cooler section (C2), wherein a first hot air pipeline (P1) is arranged between the drying blowing section (UDD) and the third annular cooler section (C3), a second hot air pipeline (P2) is arranged between the air draft drying section (DDD) and the second annular cooler section (C2), and the first hot air pipeline (P1) is connected with the second hot air pipeline (P2) through a hot air connecting pipeline (P12). The invention adopts the hot air of the annular cooler to dry the pellets, avoids HCl harmful gas generated in the pellet drying process from entering the active coke desulfurization and denitrification system, and ensures the stable and smooth operation of the active coke desulfurization and denitrification system.
Description
Technical Field
The application relates to the technical field of hot air systems of pellet grate rotary kiln processes, in particular to a hot air system of a grate rotary kiln suitable for an active coke desulfurization and denitrification process.
Background
Pellets are high-quality raw materials for blast furnace ironmaking, and compared with sintered ores, the production of pellets has the characteristics of low energy consumption, good strength, high grade and excellent metallurgical performance. The pellet production in China is mainly performed by a grate-rotary kiln process, and the pellet mineral yield of the process accounts for more than 60% of the total pellet yield. With the increasing of the national environmental protection treatment force and the implementation of new environmental protection policies, iron and steel enterprises begin to implement the ultra-low emission standard of waste flue gas, and the standard requires that the concentration of sulfur dioxide in the discharged flue gas is less than 35mg/Nm 3 Nitrogen oxide concentration less than 50mg/Nm 3 The concentration of the particles is less than 10mg/Nm 3 . The active coke desulfurization and denitrification process is a desulfurization and denitrification process which is more built in steel plants in recent years, can meet the ultralow emission standard of flue gas emission, can recover sulfur-containing flue gas to prepare sulfuric acid, and is favored by many steel enterprises. However, the construction investment cost of the active coke desulfurization and denitrification process is high, and the greater the treated flue gas amount is, the greater the construction scale is, and the higher the construction and operation costs are.
The pellet grate rotary kiln process adopts a grate to dry and pre-bake raw pellets, then the kiln is connected to bake pre-baked pellets at a higher temperature, and the baked high-temperature pellets enter a circular cooler to be cooled. The grate machine is sequentially divided into a blast drying section, an exhaust drying section, a preheating section I and a preheating section II, and the cooling process of the annular cooler is sequentially divided into a first annular cooler section, a second annular cooler section, a third annular cooler section and a fourth annular cooler section. The preheating section II of the grate is connected with the kiln tail of the rotary kiln, and the kiln head of the rotary kiln is connected with the section of the annular cooler. The hot air among the grate, the rotary kiln and the annular cooler is mutually utilized, so that the effective energy conservation of the pellet production process is realized. The hot air system is summarized as follows: the hot air of the first section of the circular cooler is supplied to the rotary kiln, the hot air of the blast drying section of the chain grate and the hot air of the preheating section I are respectively from the third section of the circular cooler and the second section of the circular cooler, the hot air of the preheating section II of the chain grate is from the kiln tail of the rotary kiln, and the hot air of the preheating section II is recycled to the induced draft drying section through the circulating fan. Refractory material partition walls are built among the sections of the grate, so that proper flow of hot air among the sections is ensured, and transition of a temperature field is realized. Wherein a partition wall between the preheating I section and the preheating II section is lifted upwards, and an opening is formed in the partition wall; the partition wall between the preheating section I and the air draft drying section is lifted upwards, and no opening exists; the partition wall between the induced draft drying section and the forced air drying section is lower and basically only allows the pellet material layer to pass through. Hot air of the preheating section I and the air draft drying section is converged into a main flue through a lower bellows, and finally enters an active coke desulfurization and denitrification process.
In the practical production process, when the active coke desulfurization and denitrification system is used for treating the flue gas in the pellet grate rotary kiln process, the active Jiao Jinghua tower is severely corroded, and crystals are often formed in the tower to block the gas path channel, so that shutdown maintenance is required, and the stable and smooth operation of the pellet process is affected. Analysis shows that a small amount of hydrogen chloride gas can be continuously generated in the production process of the pellet grate rotary kiln process and enters a flue, the hydrogen chloride gas enters an active coke purifying tower and then reacts with ammonia in an ammonia spraying area to generate ammonium chloride crystals, a reaction equation is shown in a formula (1), and finally corrosion and blockage of the purifying tower are caused.
HCl+NH 3 ＝NH 4 Cl type (1)
The research and analysis show that the generation mechanism of the hydrogen chloride gas can be expressed as follows: the pellet ore raw material contains chlorine-containing soluble salts such as sodium chloride, potassium chloride and the like; the green pellets are dried by a drying section of a drying grate and still contain higher moisture (the moisture content is 7% -8%) and enter an air draft drying section; the hot air of the induced draft drying section is from the circulating hot air of the preheating section II, and the circulating hot air contains sulfur dioxide and nitrogen oxide gas with higher concentration; sulfur dioxide in the high-temperature flue gas in the induced draft drying section reacts with chlorine-containing salts in the undried green pellets to generate hydrogen chloride gas, a typical reaction equation is shown in a formula (2), and finally generated hydrogen chloride gas enters a main flue to cause corrosion and blockage of a purifying tower.
2SO 2 +2H 2 O+O 2 +4NaCl＝2Na 2 SO 4 +4HCl type (2)
In order to reduce or inhibit the formation of hydrogen chloride gas, the contact of the undried aqueous green pellets with the flue gas rich in sulphur dioxide components is reduced in the grate. Based on the analysis, the aim can be achieved by adjusting the hot air system of the rotary kiln of the pellet grate to reduce the generation amount of hydrogen chloride components, so that the active coke desulfurization and denitrification process can stably run.
In the prior art, patent CN103335522a discloses a hot air system of a drying grate, wherein three sections of hot air of a circular cooler are supplied to a drying grate air-blast drying section, two sections of hot air of the circular cooler are supplied to an exhaust drying section, and the two sections of hot air of the circular cooler are partially supplemented to the air-blast drying section, so that the temperature of the air-blast drying section is increased, and the drying effect of the air-blast drying section is improved. The hot air system of the drying section of the drying grate provided by the patent CN103335522A aims to improve the ball drying effect of the drying section of the drying grate, and can not solve the problems of corrosion and blockage of the active coke desulfurization and denitrification system caused by hydrogen chloride components in the flue gas.
The traditional hot air system of the rotary kiln of the chain grate machine at present is expressed as follows: the pellet grate rotary kiln process adopts a grate to dry and pre-bake raw pellets, then the kiln is connected to bake pre-baked pellets at a higher temperature, and the baked high-temperature pellets enter a circular cooler to be cooled. The grate machine is sequentially divided into a blast drying section, an exhaust drying section, a preheating section I and a preheating section II, and the cooling process of the annular cooler is sequentially divided into a first annular cooler section, a second annular cooler section, a third annular cooler section and a fourth annular cooler section. The preheating section II of the grate is connected with the kiln tail of the rotary kiln, and the kiln head of the rotary kiln is connected with the section of the annular cooler. The hot air among the grate, the rotary kiln and the annular cooler is mutually utilized, so that the effective energy conservation of the pellet production process is realized. The hot air system is summarized as follows: the hot air of the first section of the circular cooler is supplied to the rotary kiln, the hot air of the blast drying section of the chain grate and the hot air of the preheating section I are respectively from the third section of the circular cooler and the second section of the circular cooler, the hot air of the preheating section II of the chain grate is from the kiln tail of the rotary kiln, and the hot air of the preheating section II is recycled to the induced draft drying section through the circulating fan. Refractory material partition walls are built among the sections of the grate, so that proper flow of hot air among the sections is ensured, and transition of a temperature field is realized. Wherein a partition wall between the preheating I section and the preheating II section is lifted upwards, and an opening is formed in the partition wall; the partition wall between the preheating section I and the air draft drying section is lifted upwards, and no opening exists; the partition wall between the induced draft drying section and the forced air drying section is lower and basically only allows the pellet material layer to pass through. The hot air of the preheating section I and the air draft drying section is converged into the main flue through the lower bellows, and finally enters the desulfurization and denitrification system.
The prior art mainly reforms a hot air system of the rotary kiln of the chain grate from the angles of energy utilization and improvement of drying effect or preheating effect of the chain grate, but does not design the content of the chain grate from the angles that the generation of hydrogen chloride gas is considered and the subsequent active coke desulfurization and denitrification process is greatly and negatively influenced.
Disclosure of Invention
The invention aims to provide a grate machine rotary kiln hot air system suitable for an active coke desulfurization and denitrification process, so as to overcome the defects in the prior art.
In order to achieve the above purpose, the present invention provides the following technical solutions: a grate kiln hot air system suitable for an active coke desulfurization and denitrification process, comprising: the novel air conditioner comprises a drying grate forced air drying section (UDD), an induced draft drying section (DDD), a preheating I section (TPH), a preheating II section (PH), a first annular cooler section (C1), a second annular cooler section (C2), a third annular cooler section (C3) and a fourth annular cooler section (C4), wherein a first hot air pipeline (P1) is arranged between the forced air drying section (UDD) and the third annular cooler section (C3), a second hot air pipeline (P2) is arranged between the induced draft drying section (DDD) and the second annular cooler section (C2), the first hot air pipeline (P1) is connected with the second hot air pipeline (P2) through a hot air connecting pipeline (P12), a butterfly valve (B1) is arranged on the hot air connecting pipeline (P12), and the butterfly valve (B1) is connected with a temperature control system.
Preferably, a first refractory wall (W1) is built between the blowing drying section (UDD) and the exhausting drying section (DDD) of the grate; a second refractory wall (W2) is built between the preheating I section (TPH) and the ventilation drying section (DDD); a third refractory wall (W3) is built between the preheating II section (PH) and the preheating I section (TPH), and the first refractory wall (W1), the second refractory wall (W2) and the third refractory wall (W3) are raised to only allow the pellet layer to pass through.
Preferably, a first fan (F1) is arranged on the first hot air pipeline (P1) to blow hot air into a blast drying section (UDD) from a three-section (C3) of the annular cooler.
Preferably, a third hot air pipeline (P3) is arranged between the preheating I section (TPH) and the preheating II section (PH), a second fan (F2) is arranged on the third hot air pipeline (P3), hot air is blown into the preheating I section (TPH) by the preheating II section (PH) by the second fan (F2), the third hot air pipeline (P3) is connected with a hot blast stove (AS), the other end of the hot blast stove (AS) is connected with the third fan (F3), and the third fan (F3) blows cold air into the hot blast stove (AS) to heat and then conveys the cold air to the third hot air pipeline (P3).
Preferably, the exhaust drying section (DDD) is connected with the environment dust removal system through a fourth hot air pipeline (P4), a fourth fan (F4) is arranged on the fourth hot air pipeline, and the fourth fan blows exhaust gas of the exhaust drying section (DDD) into the environment dust removal system.
Further, a fifth hot air pipeline (P5) is arranged between the air blast drying section (UDD) and the fourth hot air pipeline (P4), the fifth hot air pipeline (P5) discharges waste gas of the air blast drying section (UDD) into the fourth hot air pipeline (P4) to be blown into an environment dust removal system through a fourth fan (F4), a second butterfly valve (B3) is arranged on the fifth hot air pipeline (P5), and the second butterfly valve (B3) is connected with a pressure regulating system of the air blast drying section (UDD).
Preferably, a sixth hot air pipeline (P6) is arranged between the preheating I section (TPH) and the active coke desulfurization and denitrification system, and a fifth fan (F5) is arranged on the sixth hot air pipeline (P6).
Compared with the prior art, the grate machine rotary kiln hot air system applicable to the active coke desulfurization and denitrification process has the following beneficial effects:
1) Refractory wall bodies are built between the blast drying section and the exhaust drying section, between the preheating section I and the exhaust drying section, and between the preheating section II and the preheating section I of the grate. All the walls are lifted upwards, so that the pellet material layers can only be guaranteed to pass through, and the hot air between adjacent sections of the grate can be prevented from flowing mutually;
2) The high-sulfur hot flue gas led out from the lower part of the preheating section II by the regenerative fan is conveyed to the preheating section I, and in order to ensure the preheating effect of the preheating section I, an independent hot blast stove is additionally arranged, and hot air produced by the hot blast stove is conveyed to the preheating section I for supplementing heat;
3) Adding cold air into a part of hot air (without sulfur) of the annular cooling two sections, and then conveying the hot air to an exhaust drying section for drying pellets in the exhaust drying section;
4) The hot air of the second section of the residual circular cooler and the hot air of the third section of the circular cooler are conveyed to the forced air drying section through valve control, so that the temperature of the forced air drying section is increased, and the drying effect of the forced air drying section is improved;
5) Because the wall body between each section of the chain grate prevents the mutual circulation of hot air of each section, the hot air system ensures that only the flue gas exhausted from the lower part of the preheating section I needs to be subjected to desulfurization and denitrification treatment, and the flue gas is led out by the main fan and then is sent into the desulfurization and denitrification system, so that the flue gas treatment capacity is reduced, and the construction and operation cost of the desulfurization and denitrification system can be reduced.
6) The hot air led out from the lower part of the induced draft drying section and the hot air led out from the upper part of the forced draft drying section are all sulfur-free flue gas, and can be led out together to be sent into a dust removal system without being sent into a subsequent desulfurization and denitrification system.
Drawings
In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings that are required to be used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments described in the present application, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a schematic structural diagram of a grate kiln hot air system suitable for an active coke desulfurization and denitrification process according to an embodiment of the invention.
Detailed Description
The following detailed description of the technical solutions according to the embodiments of the present invention will be given with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, 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.
The invention provides a pellet chain grate rotary kiln hot air system suitable for an active coke desulfurization and denitrification process, which is shown in fig. 1, and comprises a chain grate forced air drying section UDD, an induced draft drying section DDD, a preheating section I TPH, a preheating section II PH, a ring cooler second section C2 and a ring cooler third section C3. The hot air of the blowing drying section UDD of the chain grate mainly comes from a third section C3 of the annular cooler, and part of hot air comes from a second section C2 of the annular cooler; the hot air of the air draft drying section DDD comes from a second section C2 of the annular cooler, and partial cold air is added; the hot air for preheating the section I TPH comes from the circulating hot air for preheating the section II PH, and is added with the hot air generated by the independent hot air furnace AS; after the pellets are dried, the flue gas of the induced draft drying section DDD and the flue gas of the forced draft drying section UDD are discharged to an environment dust removing system together, and the discharged flue gas of the pre-heating section I TPH enters an active coke desulfurization and denitrification system.
Preferably, a refractory wall W1 is built between the blowing drying section UDD and the exhausting drying section DDD of the grate; a refractory wall W2 is built between the preheating I section TPH and the ventilation drying section DDD; a refractory wall W3 is built between the preheating II section PH and the preheating I section TPH. All the walls are lifted upwards, so that the pellet material layers can only pass through, and hot air circulation among adjacent sections of the grate can be effectively prevented through the lifted walls.
Preferably, a hot air pipeline P1 is arranged between the blowing and drying section UDD of the chain grate and the three sections C3 of the annular cooler, and a fan F1 is arranged on the hot air pipeline P1 to blow hot air into the blowing and drying section UDD of the chain grate; a hot air pipeline P2 is arranged between the ventilation drying section DDD and the second section C2 of the annular cooler, and the hot air pipeline P1 is connected with the hot air pipeline P2 through a hot air pipeline P12; the hot air pipeline P12 is provided with a butterfly valve B1, and the opening of the butterfly valve B1 is regulated by a temperature control system. The temperature of the hot air from the third section C3 of the circular cooler in the hot air duct P1 is about 280℃ and after being fed to the drying section UDD of the grate air blast, the temperature is reduced to 150℃. In this case, the drying effect of the hot air in the hot air duct P1 on the pellets of the drying section UDD of the grate air blast is relatively poor, the dehydration rate is less than 10%, and the moisture of the pellets after entering the suction drying section DDD is still high. In the specific implementation process, by increasing the opening of the butterfly valve B1, part of high-temperature hot air of the second section C2 of the circular cooler is pumped into the hot air pipeline P1 with relatively low temperature due to the action of the fan F1, so that the temperature of the hot air pipeline P1 is increased, the incoming air temperature of the blast drying section of the grate is 180-200 ℃, the drying effect on raw balls in the blast drying section UDD of the grate is improved, and the dehydration rate of the raw balls reaches 15%.
Preferably, a hot air pipeline P2 is arranged between the air draft drying section DDD and the annular cooler second section C2, and the negative pressure in the air draft drying section pumps the hot air of the annular cooler second section into the air draft drying section through the hot air pipeline P2 for continuously drying the moisture in the green pellets. Because the temperature of hot air of the second section C2 of the annular cooler is about 700 ℃, the hot air directly enters the DDD of the air draft drying section to dry the pellets, the pellets burst, and the return ore quantity is increased. The back section of the hot air pipeline P2 is provided with a cold air valve B2, the opening of the cold air valve B2 can be adjusted according to the temperature in the exhaust drying section DDD, and meanwhile, the power adjustment of the exhaust gas outlet fan F4 of the exhaust drying section DDD is matched to control the temperature of hot air in the exhaust drying section to 300-350 ℃, and the pressure in the exhaust drying section to-150 to-200 pa, so that pellets are completely dried at the tail end of the exhaust drying section DDD.
Preferably, a hot air pipeline P3 is arranged between the preheating I section TPH and the preheating II section PH, and a fan F2 is arranged on the hot air pipeline P3 to lead out hot air from the lower part of the preheating II section PH and blow in the hot air from the upper part of the preheating I section TPH. The process of extracting the hot air of the preheating section II by the fan F2 passes through the water-cooling protection system of the preheating section II, so that the temperature of the hot air entering the hot air pipe P3 is greatly reduced, the temperature is about 350 ℃, and the temperature requirement of the preheating section I TPH on pellet pre-roasting cannot be met. The air blower F3 is used for blowing cold air into the hot air furnace AS to heat, and hot air generated by heating is connected to the rear section of the hot air pipeline P3, so that the temperature of the hot air for preheating the I section TPH reaches about 750 ℃, and the negative pressure in the preheating I section TPH is ensured to be between-100 pa and-200 pa by matching the induced draft fan F5 for preheating the waste gas outlet of the I section TPH with the fan F2 and the fan F3.
Preferably, the lower part of the induced draft drying section DDD is connected with a hot air pipeline P4, and the tail end of the hot air pipeline P4 is connected with a fan F4. The upper part of the blowing and drying section UDD of the grate is connected with a hot air pipeline P5, and the hot air pipeline P5 is connected with a hot air pipeline P4. The hot air pipeline P5 is provided with a butterfly valve B3, and the opening of the butterfly valve B3 is regulated by a pressure detection system in the blowing and drying section UDD of the grate. And the opening degree of the butterfly valve B3 is adjusted so that the negative pressure in the blowing and drying section UDD of the grate is about 50pa, and the fan F4 discharges the waste gas after the pellets are dried in the blowing and drying section UDD of the grate and the exhausting and drying section DDD into an environment dust removing system.
Preferably, a hot air pipeline P6 is arranged at the lower part of the preheating I section TPH, the tail end of the hot air pipeline P6 is connected with a fan F5, and the fan F5 leads out hot flue gas in the preheating I section TPH and sends the hot flue gas into an active coke desulfurization and denitrification system.
The pellet grate rotary kiln hot air system suitable for the active coke desulfurization and denitrification process has the characteristics and advantages that:
1. the hot air system of the pellet grate rotary kiln is provided based on the objective fact that the corrosion and the blockage of crystals occur in an active coke purifying tower due to the generation of hydrogen chloride gas in flue gas during production practice of an active coke desulfurization and denitrification process by the pellet grate rotary kiln. Based on the mechanism of hydrogen chloride gas generation in the grate, a hot air control concept is proposed to reduce the contact of the undried aqueous green pellets with the flue gas rich in sulfur dioxide components in the grate. The hot air system avoids the adoption of the circulating hot flue gas which is rich in high-concentration sulfur dioxide and nitrogen oxides and is used for preheating the II section in the traditional grate rotary kiln hot air system to dry the water-containing pellets in the induced draft drying section, but adopts the hot air generated in the two sections of the annular cooler to dry the water-containing pellets in the induced draft drying section by adding cold air, thereby inhibiting the generation of hydrogen chloride gas and ensuring the stable and smooth operation of the active coke desulfurization and denitrification process.
2. According to the pellet grate rotary kiln hot air system, hot air generated in the second section of the annular cooler is added with cold air, and the cold air is introduced into the exhaust drying section to dry the water-containing green pellets, so that the temperature is proper in the drying process, and the exhaust gas in the exhaust drying section basically does not contain sulfur dioxide and nitrogen oxide components, so that the exhaust gas does not need to enter an active coke desulfurization and denitrification process. The hot air of the preheating section II is circulated to the preheating section I for pre-roasting the pellets, and in order to ensure the temperature and the air quantity of the hot air of the preheating section I, the system is provided with an independent hot air furnace for supplementing the temperature and the air quantity of the incoming air of the preheating section I. Thus, the waste flue gas containing sulfur dioxide, nitrogen oxides and other components is only discharged from the preheating section I and enters the active coke desulfurization and denitrification process, the treated flue gas quantity is greatly reduced, the construction scale of the active coke desulfurization and denitrification process can be reduced, and the investment cost and the operation cost are reduced.
It is noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises an element.
The foregoing is merely exemplary of the application and it should be noted that modifications and adaptations to those skilled in the art may be made without departing from the principles of the application and are intended to be comprehended within the scope of the application.
Claims (6)
1. A grate kiln hot air system suitable for an active coke desulfurization and denitrification process, comprising: the drying grate comprises a drying blowing section (UDD), an air draft drying section (DDD), a preheating I section (TPH), a preheating II section (PH), a first annular cooler section (C1), a second annular cooler section (C2), a third annular cooler section (C3) and a fourth annular cooler section (C4), wherein a first hot air pipeline (P1) is arranged between the drying blowing section (UDD) and the third annular cooler section (C3), and is characterized in that: a second hot air pipeline (P2) is arranged between the air draft drying section (DDD) and the annular cooler second section (C2), the first hot air pipeline (P1) is connected with the second hot air pipeline (P2) through a hot air connecting pipeline (P12), a butterfly valve (B1) is arranged on the hot air connecting pipeline (P12), the butterfly valve (B1) is connected with a temperature control system, and a first refractory wall (W1) is built between the drying section (UDD) of the chain grate air draft and the drying section (DDD); a second refractory wall (W2) is built between the preheating I section (TPH) and the ventilation drying section (DDD); a third refractory wall (W3) is built between the preheating II section (PH) and the preheating I section (TPH), and the first refractory wall (W1), the second refractory wall (W2) and the third refractory wall (W3) are raised to only allow the pellet layer to pass through.
2. The grate kiln hot air system suitable for an active coke desulfurization and denitrification process as claimed in claim 1, wherein the hot air system is characterized in that: the first hot air pipeline (P1) is provided with a first fan (F1) for blowing hot air into a blast drying section (UDD) from a three-section (C3) of the annular cooler.
3. The grate kiln hot air system suitable for an active coke desulfurization and denitrification process as claimed in claim 1, wherein the hot air system is characterized in that: the preheating device is characterized in that a third hot air pipeline (P3) is arranged between the preheating I section (TPH) and the preheating II section (PH), a second fan (F2) is arranged on the third hot air pipeline (P3), hot air is blown into the preheating I section (TPH) by the preheating II section (PH) by the second fan (F2), the third hot air pipeline (P3) is connected with a hot blast stove (AS), the other end of the hot blast stove (AS) is connected with the third fan (F3), and the third fan (F3) is used for blowing cold air into the hot blast stove (AS) and then conveying the cold air to the third hot air pipeline (P3).
4. The grate kiln hot air system suitable for an active coke desulfurization and denitrification process as claimed in claim 1, wherein the hot air system is characterized in that: the exhaust drying section (DDD) is connected with the environment dust removal system through a fourth hot air pipeline (P4), a fourth fan (F4) is arranged on the fourth hot air pipeline, and exhaust gas of the exhaust drying section (DDD) is blown into the environment dust removal system by the fourth fan.
5. The grate kiln hot air system suitable for the active coke desulfurization and denitrification process as claimed in claim 4, wherein the hot air system is characterized in that: a fifth hot air pipeline (P5) is arranged between the forced air drying section (UDD) and the fourth hot air pipeline (P4), the fifth hot air pipeline (P5) discharges waste gas of the forced air drying section (UDD) into the fourth hot air pipeline (P4) to be blown into an environment dust removal system through a fourth fan (F4), a second butterfly valve (B3) is arranged on the fifth hot air pipeline (P5), and the second butterfly valve (B3) is connected with a pressure regulating system of the forced air drying section (UDD).
6. The grate kiln hot air system suitable for an active coke desulfurization and denitrification process as claimed in claim 1, wherein the hot air system is characterized in that: a sixth hot air pipeline (P6) is arranged between the preheating I section (TPH) and the active coke desulfurization and denitrification system, and a fifth fan (F5) is arranged on the sixth hot air pipeline (P6).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110434236.6A CN113188335B (en) | 2021-04-22 | 2021-04-22 | Chain grate rotary kiln hot air system suitable for active coke desulfurization and denitrification process |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110434236.6A CN113188335B (en) | 2021-04-22 | 2021-04-22 | Chain grate rotary kiln hot air system suitable for active coke desulfurization and denitrification process |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113188335A CN113188335A (en) | 2021-07-30 |
| CN113188335B true CN113188335B (en) | 2023-12-26 |
Family
ID=76978098
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110434236.6A Active CN113188335B (en) | 2021-04-22 | 2021-04-22 | Chain grate rotary kiln hot air system suitable for active coke desulfurization and denitrification process |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113188335B (en) |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| ZA200003024B (en) * | 1999-09-17 | 2001-01-09 | Mitsubishi Heavy Ind Ltd | Apparatus for producing reduced iron and compact drying method applied to the apparatus. |
| CN101900489A (en) * | 2010-09-08 | 2010-12-01 | 中冶北方工程技术有限公司 | Grate-kiln-circular cooler furnace drying device and furnace drying method thereof |
| CN102121786A (en) * | 2011-03-08 | 2011-07-13 | 中冶北方工程技术有限公司 | Hot air system of grate-rotary kiln-circular cooler |
| CN102252530A (en) * | 2011-07-15 | 2011-11-23 | 中冶北方工程技术有限公司 | Novel waste heat utilization and emission reduction process for hot air systems of chain grate machine, rotary kiln and circular cooler |
| CN103335522A (en) * | 2013-07-31 | 2013-10-02 | 中冶北方（大连）工程技术有限公司 | Grate forced air drying section hot air system |
| CN204806887U (en) * | 2015-06-24 | 2015-11-25 | 洛阳矿山机械工程设计研究院有限责任公司 | Hot air system with adjustable drying grate |
| CN110894573A (en) * | 2019-07-22 | 2020-03-20 | 中冶长天国际工程有限责任公司 | Production process and system for oxidizing pellets by using grate-rotary kiln system |
| CN211367682U (en) * | 2019-07-22 | 2020-08-28 | 中冶长天国际工程有限责任公司 | Grate-rotary kiln system |
| WO2021056830A1 (en) * | 2019-09-23 | 2021-04-01 | 中国科学院过程工程研究所 | Denitration treatment system and treatment method for flue gas from pellet roasting by chain grate machine-rotary kiln |
-
2021
- 2021-04-22 CN CN202110434236.6A patent/CN113188335B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| ZA200003024B (en) * | 1999-09-17 | 2001-01-09 | Mitsubishi Heavy Ind Ltd | Apparatus for producing reduced iron and compact drying method applied to the apparatus. |
| CN101900489A (en) * | 2010-09-08 | 2010-12-01 | 中冶北方工程技术有限公司 | Grate-kiln-circular cooler furnace drying device and furnace drying method thereof |
| CN102121786A (en) * | 2011-03-08 | 2011-07-13 | 中冶北方工程技术有限公司 | Hot air system of grate-rotary kiln-circular cooler |
| CN102252530A (en) * | 2011-07-15 | 2011-11-23 | 中冶北方工程技术有限公司 | Novel waste heat utilization and emission reduction process for hot air systems of chain grate machine, rotary kiln and circular cooler |
| CN103335522A (en) * | 2013-07-31 | 2013-10-02 | 中冶北方（大连）工程技术有限公司 | Grate forced air drying section hot air system |
| CN204806887U (en) * | 2015-06-24 | 2015-11-25 | 洛阳矿山机械工程设计研究院有限责任公司 | Hot air system with adjustable drying grate |
| CN110894573A (en) * | 2019-07-22 | 2020-03-20 | 中冶长天国际工程有限责任公司 | Production process and system for oxidizing pellets by using grate-rotary kiln system |
| CN211367682U (en) * | 2019-07-22 | 2020-08-28 | 中冶长天国际工程有限责任公司 | Grate-rotary kiln system |
| WO2021056830A1 (en) * | 2019-09-23 | 2021-04-01 | 中国科学院过程工程研究所 | Denitration treatment system and treatment method for flue gas from pellet roasting by chain grate machine-rotary kiln |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113188335A (en) | 2021-07-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109373767B (en) | Pellet flue gas ultralow NOxDischarged production process and system | |
| CN109055721B (en) | Grate-rotary kiln pellet low NOxProduction process and system | |
| CN109136545B (en) | Grate-rotary kiln pellet low NOxProduction process and system thereof | |
| CN109136544B (en) | Grate-rotary kiln pellet low NOxProduction process and system thereof | |
| CN211367682U (en) | Grate-rotary kiln system | |
| CN110894573B (en) | Production process and system for oxidizing pellets by using grate-rotary kiln system | |
| CN104195326A (en) | Sintering energy-saving technique and system capable of removing multiple pollutants | |
| CN110075680B (en) | Desulfurization, denitrification, dust removal and ultralow emission process and system for producing cement from low-sulfur raw materials | |
| CN105135895A (en) | Selective sintering flue gas sectional type comprehensive treatment technology | |
| CN108931141B (en) | A kind of technique for realizing inexpensive denitration using sinter waste-heat sintered discharge gas | |
| CN209854219U (en) | Grate-rotary kiln pellet low NOx emission system | |
| CN110894574B (en) | Chain grate machine, and denitration system and method for oxidized pellets of rotary kiln of chain grate machine | |
| CN209386820U (en) | A kind of production system of pelletizing flue gas ultra-low NOx emission | |
| CN110052158B (en) | Calcium circulation dry desulfurization system based on cement clinker production line | |
| CN101117652A (en) | Gas modifying combustion-compensating device for converter evaporation cooling air flue | |
| CN113188335B (en) | Chain grate rotary kiln hot air system suitable for active coke desulfurization and denitrification process | |
| CN112833413A (en) | Optimized grate-rotary kiln SCR denitration system and denitration process thereof | |
| CN108088250B (en) | Thermal system of belt type roasting machine and control method thereof | |
| CN101172652A (en) | Alum mine calcium method marching type roasting method and roasting furnace | |
| CN113186390B (en) | Hot air system of rotary kiln of chain grate machine | |
| CN102060197A (en) | Pneumatic conveying method and system of pulverized coal | |
| CN215627653U (en) | Low-calorific-value fuel flue gas system suitable for double-hearth kiln | |
| CN108955277A (en) | A kind of system for realizing inexpensive denitration using sinter waste-heat sintered discharge gas | |
| CN211373267U (en) | System for pelletizing ring cooling waste gas waste heat high-efficient utilization | |
| CN207113629U (en) | A kind of system for realizing inexpensive denitration using sintering deposit waste-heat sintered discharge gas |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |