Write the Precautions for Safety of Cupola Furnace.

For operating the cupola successfully, the following safety precautions must always be kept into account.

• For safety of Cupola, better quality refractory lining must be used for preparing or repairing furnace so that it can withstand high temperature as produced inside the furnace during melting, otherwise it will fuse and mix with molten metal to form slag.

• The furnace operator during firing the furnace should always make an effort to place the metal charge in the centre. He must ensure that the coke charge is well distributed all around and towards the firebrick lining to ensure uniform and thorough melting of the metal.

• As the air passes through the tuyeres, the temperature near the tuyere openings will therefore be comparatively lower and consequently the molten iron and slag will have a tendency to solidify near these openings and block them. This should be prevented by frequent poking and removal of these materials by means of a poking rod through the tuyeres.

• Amount of air supply should be properly controlled. An excess amount of air will always result in waste of fuel and lowering of temperature inside and a lesser amount, than required, will cause incomplete combustion of fuel which is undesirable.

• Tap hole must be properly closed by means of a well suitable plugging means. Clay mixed with an equal amount of coal dust forms a very suitable mixture for plugging up the tap hole.

• In closing the tap-hole, precaution must be taken to press the plug downwards in the hole so that the splash of the molten metal, during plugging does not fall on the hands of the furnace operator.

• Molten metal should always be tapped out well in time before its level rises too high in the well of the cupola furnace. Any delay of tapping molten metal, the slag floating on the surface of the molten metal, will start flowing into the wind belt through the tuyeres and air passage will be choked and it will result in severe problem of the jamming of cupola furnace.