Capital Repairs of a Blast Furnace Sep01

Capital Repairs of a Blast Furnace...

Capital Repairs of a Blast Furnace Capital repairs of a blast furnace are those repairs which are taken up after the end of a campaign of the blast furnace. During the capital repairs the main jobs which are normally taken up are (i) relining of the furnace, (iii) repairs of the damaged portion of the shell, (iii) Major revisioning of all the equipment with replacement of the worn out components, (iv) replacement of those equipments, instruments and automation items which have become obsolete or completed their useful life, and (v) modification work the need of which was felt during the running of the blast furnace in the campaign which has just ended. Since the campaign of a blast furnace lasts for a long time (10 years to 20 years), technology upgradation takes place during this period. Hence it becomes necessary to incorporate these technological upgradation features in the blast furnace during the capital repairs. This keeps the blast furnace up to date in its new campaign. Capital repairs also provide opportunity to steel plant to improve the lining features of the furnace and to enhance the internal volume and hence the capacity of the blast furnace. The improvement in the lining features also help in the enhancement in the campaign life of the blast furnace. Planning for the capital repairs Capital repairs of the blast furnace are normally a time bound activity which is to be completed within the shortest possible time and in the assigned budget and hence accurate and close planning is very important for the successful completion of the capital repairs. Planning is required to be done to the minute levels. The achievement of the success in timely completion of the capital repairs within the estimated costs depends on how accurate...

Salamander Tapping for Capital Repairs of Blast Furnace Aug26

Salamander Tapping for Capital Repairs of Blast Furnace...

Salamander Tapping for Capital Repairs of Blast Furnace  A salamander means all liquid and solidified materials in the hearth of a blast furnace below the tap hole. The salamander includes liquid iron and slag and mixtures of solid iron, slag and coke/carbon. During the normal operation of the blast furnace, the furnace bottom and hearth contains the ‘dead-man’ and the salamander. When the blast furnace is to be relined, it is necessary that the furnace is emptied completely by removing all the constituents of the bottom and the hearth. It is also desirable to remove these constituents during partial relining of the furnace or during the repairs of the tap-hole. This provides safer working conditions during these partial repairs and prevents damage to the hearth refractories as a result of cyclic cooling and heating movements. The removal of all the constituents of the bottom and the hearth of the furnace is carried out usually by salamander tapping. The salamander tapping is usually done at preferably the lowest level where liquid iron can be expected in the blast furnace hearth. Salamander tapping of a blast furnace is the final tapping after the furnace is blown down in order to drain the last liquid iron from the furnace hearth. Because of its rare occurrence a salamander tapping represents in most of the steel plants a specialized job which requires a lot of preparation. A solidified salamander is normally difficult to remove especially if there is titanium in it. A large quantity of solid salamander can delay the critical path of the capital repairs of the blast furnace by a number of days or even by weeks. For the removal of the solidified salamander often requires oxygen lancing and even explosives. These types of removal also cause health and safety...