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...

Methods of Shutting Down a Blast Furnace May05

Methods of Shutting Down a Blast Furnace...

Methods of Shutting Down a Blast Furnace A blast furnace, after it is blown in and the production of hot metal starts, runs for a large number of years  before it is put down for relining. This continuous run of the blast furnace is known as campaign life. In modern blast furnaces  a campaign life of 15 years to 20 years is expected. When a furnace has reached the end of its campaign, it was usually blown out/blown down. Between the blown in to blown out/blown down, the blast furnace may have to be shut down for short periods due to various reasons. The various types of shut downs of a blast furnace are described below. (Fig 1) Fig 1 Important methods of shutting down a blast furnace  Fanning Very often while running of the blast furnace, a situation can arise when the full productive capacity of the furnace is not required for a period of time. This can be due to some problems which may arise in downstream or upstream facilities. When this occurs, the problem can be solved either by the shutting the blast furnace down or curtailing the operation of the blast furnace by reducing the quantity of hot blast. The hot blast rate is usually reduced until the hot blast pressure at the tuyeres is very low. However, it is a must that a positive pressure is kept in the hot blast system to assure that there is no danger of blast furnace gas coming back from the blast furnace into the blower system. The technique of reducing the hot blast volume to less than 20 % to 25 % of normal is known as fanning. Fanning has the advantages of keeping the blast furnace gas system pressurized and furnishing...