Unit 4 Hot blast stove

1、SMM, NEU2022-7-421regulate調(diào)節(jié)，校準(zhǔn)調(diào)節(jié)，校準(zhǔn)2chamber室，房間室，房間3combustion chamber燃燒室燃燒室4checkerwork格式裝置，砌磚格格式裝置，砌磚格5minimize將將減到最少減到最少6line管線管線7weld焊接，熔接焊接，熔接8cylinder圓筒，圓柱體圓筒，圓柱體9checker mass蓄熱室蓄熱室10burner燃燒器燃燒器11air stream風(fēng)流，空氣流風(fēng)流，空氣流12recommend使成為可取，推薦使成為可取，推薦13requirement需求，要求需求，要求14pack填塞，塞滿填塞，塞滿15checke

2、r brick格子磚格子磚16volume ratio體積比，容積比體積比，容積比SMM, NEU2022-7-4317efficiency效率，效能效率，效能18assure保證，擔(dān)保保證，擔(dān)保19checker chamber蓄熱室蓄熱室20flue煙道，通氣管煙道，通氣管21vertically垂直的垂直的22align排列排列23ratio比，比率，比值比，比率，比值24enrich使富足，使富化使富足，使富化25on blast送風(fēng)，鼓風(fēng)送風(fēng)，鼓風(fēng)26natural gas天然氣天然氣27coke oven焦?fàn)t焦?fàn)t28intense強(qiáng)烈的，劇烈的強(qiáng)烈的，劇烈的29compress壓縮

3、壓縮30progressively逐漸的，漸近的逐漸的，漸近的31bypass繞過，使繞過，使通過旁道通過旁道32constant恒定的，不變的恒定的，不變的SMM, NEU2022-7-4433mixer valve混風(fēng)閥混風(fēng)閥34equal相等的，均等的相等的，均等的35necessitate成為必要成為必要36specification規(guī)格，技術(shù)要求規(guī)格，技術(shù)要求37turbulent渦流的，狂暴的渦流的，狂暴的38exhaust排氣排氣(v)；廢氣；廢氣(n)39chimney煙囪煙囪40valve閥門閥門41aim目標(biāo)，目的目標(biāo)，目的(n)；以；以為目標(biāo)為目標(biāo)(v)42initial

4、最初的，開始的最初的，開始的43preset事先調(diào)整，預(yù)調(diào)事先調(diào)整，預(yù)調(diào)44automation自動控制，自動操作自動控制，自動操作45blend混合混合46dictate要求，規(guī)定要求，規(guī)定47cycle循環(huán)循環(huán)48dome圓頂，圓屋頂圓頂，圓屋頂SMM, NEU2022-7-4549alumina氧化鋁，礬土氧化鋁，礬土50whereas然而，反之然而，反之51creep蠕變，蠕動蠕變，蠕動52creep-resistant抗蠕變的抗蠕變的53silica硅石，二氧化硅硅石，二氧化硅54resist抵抗，承受抵抗，承受55thermal熱的，熱量的熱的，熱量的56alkali堿堿(n)；堿

5、性的；堿性的(adj)57dependent on依靠，由依靠，由(隨隨)決定的決定的58contamination污染，污染物污染，污染物59skinwall隔墻隔墻60backdraft倒轉(zhuǎn)，逆通風(fēng)倒轉(zhuǎn)，逆通風(fēng)61conispherical dome圓頂圓頂62enlarge擴(kuò)大，擴(kuò)展擴(kuò)大，擴(kuò)展63breech煙道煙道64exchanger換換(放、散放、散)熱器熱器SMM, NEU2022-7-46 Each hot blast stove is a large exchanger to preheat blast furnace air. It can utilize the heat

6、ing value of the furnace off-gases to heat the blast air to 1000 to 1350 C. When well designed and operated, the thermal efficiency of the stoves will be 80% to 85%. The stove consists of several parts: the shell, the combustion chamber, the checker work, and control valves and lines that regulate a

7、nd deliver the various gasses (see the right figure).SMM, NEU2022-7-47The shell is a welded steel cylinder 6 to 9 m in diameter, and typically 20 to 40m high and its insides are lined with refractory. The combustion chamber is arranged at the inside, top or outside. Therefore, there are three types

8、of hot stoves- internal-combustion, top-combustion, external-combustion stoves. They have the same principle of operation. The size of the combustion chamber should be minimized so that the checker mass is as large as possible. The design of the stove burner is critical in assuring good combustion a

9、nd efficient, stable operation. Internal ceramic burners with high mixing capability of the gas and air streams are recommended to meet this requirement. The checker chamber is packed with checker bricks which provide many small, vertically aligned flues for the high temperature gasses. The efficien

10、cy of the stove is improved as the surface area to volume ratio for the checker mass is increased.SMM, NEU2022-7-48 Normal operation utilizes three stoves. One is always on blast, while the other two are on gas. When on gas, combustion air and clean blast furnace gas are introduced into the combusti

11、on chamber. The blast furnace gas may be enriched by either natural gas or coke oven gas as necessary. The turbulent mixing of the gas and air streams results in a short, intense flame after ignition. Flame temperatures of 1200 to 1400 C are common. By the time the hot gases have passed downward thr

12、ough the checker mass, the temperature of the gases will have been reduced to 300 to 400 C before being exhausted through the chimney valves.SMM, NEU2022-7-49 The stove is PLC controlled with the aim of dome temperature and waste gas temperature. In the initial stage, the dome temperature is lower t

13、han the preset value, large flow rate of gas and air with reasonable fuel/air ratio is adopted for fast automation combustion. When the preset dome temperature is reached, then taking the dome temperature as target for auto control, i.e. keep the constant gas flow and enlarge the air flow. When the

14、preset waste gas temperature is reached, then the operating mode auto change to let the waste gas temperature as target for auto control.SMM, NEU2022-7-410 When on blast, compressed cold blast air is forced upward through the checker chamber (being progressively heated) exiting the stove through the

15、 hot blast valve. A portion of the cold blast is bypassed around the stove and is reintroduced to the hot blast system. This blending ensures a constant hot blast temperature. The mixer valve is open at the start of each cycle and closes progressively until the hot air leaving the stove is equal in

16、temperature to the desired hot blast temperature. Further loss of temperature in the stove dictates changing to another stove and starting the next cycle.SMM, NEU2022-7-411 The refractory design in hot blast furnace is also changing rapidly as higher blast temperatures are employed to reduce coke co

17、nsumption. The refractories in stoves producing higher blast temperatures obviously require higher overall stove operating temperatures. Higher alumina-content refractories can be used to safely raise stove dome temperature to 1315 C, whereas further increases require the use of special creep-resist

18、ant silica refractories. Refractories in stoves must also resist thermal cycling and the effects of alkali and iron oxide. The life of refractories in stoves may be quite long, but is strongly dependent on the extent of contamination of the stove by impurities in the gas containing significant quant

19、ities of iron or alkali backdrafted through the stoves.SMM, NEU2022-7-4121. How many types of the hot blast stoves are there nowadays?2. How many parts does the hot blast stove consists of ?3. Where can the combustion chamber be arranged?4. When is the efficiency of the stove improved?5. What are th

20、e common flame temperatures in the hot blast stove?6. When is the mixer valve open?7. Is the dome temperature lower or higher than the preset value in combustion initial stage?SMM, NEU2022-7-413 1. 內(nèi)燃式熱風(fēng)爐內(nèi)燃式熱風(fēng)爐 2. 燃燒室燃燒室 3. 格子磚格子磚 4. 陶瓷燃燒器陶瓷燃燒器 5. 煙囪煙囪 6. 冷風(fēng)閥冷風(fēng)閥 7. 蓄熱室蓄熱室 8. 高溫高溫 9. 天然氣天然氣 10. 送風(fēng)送風(fēng)

21、11. 體積比體積比 12. 壓縮空氣壓縮空氣SMM, NEU2022-7-4141. Each hot blast s_ is a large heat exchanger utilizing the heating value of the furnace off-gases to heat the blast air to 1000 to 1200C.2. The stove consists of several parts: the shell, the c_ chamber, the checker work, and control valves and lines that r

22、egulate and deliver the various gases.3. The size of the combustion chamber should be m_ so that the checker mass is as large as possible.4. Normal operation utilizes three stoves such that one is always on b_, while the other two are on gas.5. The l_ of refractories in stoves may be quite long, but

23、 is strongly dependent on the extent of contamination of the stove by impurities in the gas containing significant quantities of iron oxide or alkali backdrafted through the stoves.SMM, NEU2022-7-415 Normal operation utilizes three stoves such that one is always on blast, while the other two are _ g

24、as. When on gas, combustion air and clean blast furnace gas are introduced _ the combustion chamber. The blast furnace gas may be enriched _ either natural gas or coke oven gas as necessary. The turbulent mixing _ the gas and air streams results _ a short, intense flame _ ignition. Flame temperature

25、s _ 1200 to 1400C are common. _ the time the hot gases have passed downward _ the checker mass, the temperature of the gases will have been reduced to 300 _ 400 C before being exhausted through the chimney valves.SMM, NEU2022-7-4161. Each stove is a large heat exchanger utilizing the heating value o

26、f the blast furnace off-gases to heat the blast air to 2000 to 2300 C. ( )2. By the time the hot gasses have passed downward through the checker mass, the temperature of the gases will have been reduced to 1000 to 1200 C before being exhausted through the chimney valves. ( )3. A portion of the cold blast is bypassed around the stove and is reintroduced to the hot blast system. ( )4. The stove consists of several parts: the shell, the combustion chamber, the checker work, and control valves and lines that re