《轮机英语lesson17》由会员分享，可在线阅读，更多相关《轮机英语lesson17（81页珍藏版）》请在金锄头文库上搜索。
1、Jimei university,Lesson 17,Boiler Management,Jimei university,General management principles and operating procedures are well known and must always be followed to avoid boiler mishaps(意外事故、损坏). In particular:,Jimei university,With many small package boilers, the automatic control sequence usually en
2、sures that the boiler fire is initially ignitedlighted from a diesel oil supply,Jimei university,and changed over to the usual source when ignition is completed.,Jimei university,With good management, to facilitate subsequent starting from cold, the fuel system of large boilers will have been flushe
3、d through with diesel oil when the boiler was on light duty immediately prior to being secured.,Jimei university,When burning such diesel fuel it is essential for safety that only the correct (small) burner tip(锅炉燃烧器喷油嘴) should be used.,Jimei university,It should be kept in mind that if fire does no
4、t light, immediately shut off fuel and vent furnace.,Jimei university,Complete ignition of fuel in the furnace is essential. The burner flame, the smoke indicator(烟气指示器) and the funnel should be frequently observed.,Jimei university,With satisfactory combustion, the flame should appear incandescent(
5、发白热光的) with an orange shade(色度) at the flame tip, and a faint brownish haze(烟雾、薄雾) should show at the funnel.,Jimei university,If on first ignition the flame is uncertain, badly shaped and separated from the primary swirler(旋流), momentary opening or closing of air register(调风门)air regulator may corr
6、ect.,Jimei university,The pH value of the boiler feed water should be kept between 8 and 9 and the boiler density less than 300 ppm.,Jimei university,But, if water samples show a heavy concentration of suspended mater, short blow-downs of 20 seconds duration should be given until the sludge content
7、is seen reduced.,Jimei university,The boiler should be blown down when the oil burner is operating, the water level lowered and then restored to prove the functioning of the low water cut-out and the oil burner start-up equipment.,Jimei university,The boiler scum valve should also be operated at thi
8、s time to keep the water level clear from floating scum.,Jimei university,Fuel burner components and igniter electrodes should be cleaned weekly and the furnace examined to ensure that there are no excess carbon deposits.,Jimei university,Tubes in the exhaust gas section of the boiler should be brus
9、hed through at about six-monthly intervals, and those in the oil burning section periodically examined and cleaned as necessary with a wire bristle brush.,Jimei university,With correct feed water treatment, blow down procedures and sludge contents in water samples at a stable level, it should not be
10、 necessary to wash out the water side of the boiler more than once every three or four months.,Jimei university,Boiler fires may be out for long periods when a ship is at sea and the boiler steaming maintained by heat input from waste heat recovery plant.,Jimei university,This operation is free from
11、 hazard(危险), but feed water and boiler water treatment must be maintained to prevent internal deterioration or scale formation.,Jimei university,Water level controllers must be kept operable to protect external steam-using plant from water “carry-over”(蒸汽携水、汽水共腾) danger.,Jimei university,If a boiler
12、 is isolated from the steam-using system it must be kept either in closed dry storage with a suitable internal desiccant(干燥剂), or completely full of treated water,Jimei university,or under a low steam pressure preferably maintained by a steam-heated coil.,Jimei university,Regular testing of boiler p
13、rotective devices must be implemented(执行).,Jimei university,Frequent comparison of drum-mounted and remote-reading water level indicators:,Jimei university,discrepancies between these have contributed to failures because of overheating through shortage of water, when a boiler was being oil-fired.,Ji
14、mei university,If in doubt as to the true boiler water level, i.e. whether a water level indicator sightglass is completely full or empty, when a unit is being oil-fired the fire should be immediately extinguished until the true level is resolved(恢复).,Jimei university,Procedures should be predetermi
15、ned and followed in the event of shortage of water, bulging(凸出) or fracture(破裂) of plates or furnace, or bursting of water tubes.,Jimei university,In general, fires should be immediately extinguished by remote tripping of fuel supply valves(供油远程速闭阀);,Jimei university,forced draught air pressure main
16、tained if there is any risk of escaping steam entering the boiler room;,Jimei university,steam pressure relieved if metallic(金属的) fractures seem possible; and boiler water level maintained, where practicable, until the boiler begins to cool down.,Jimei university,Regular operation of soot blowers, if these are fitted, when the boiler is on oil-fired operation.,Jimei university,The steam supply line must be thoroughly warmed and drained before the blowers are used, the air/fuel ratio increased throughout the action, and blowers greased after use.,
