The need for spare parts is limited, as the graphite blocks and wire ropes are interchangeable between the inlet and outlet seals. The graphite blocks for the FLSmidth graphite seal are designed to ensure long life and optimum performance while keeping the required maintenance to a minimum. 

The expected wear on the graphite blocks is 5-8 mm per year, which amounts to an expected lifetime of 3-5 years depending on conditions. The wire is designed to run for a full production campaign. The mechanical and thermal properties of graphite make it an ideal sealing material. The carefully selected material means that the graphite blocks are very hard and resistant to wear, yet flexible enough to conform to mating faces, thus ensuring a tight seal. 

The low coefficient of friction and the self-lubricating properties of graphite make it ideal for application where normal lubricants cannot be used. It also extends the graphite blocks’ lifetime. Even high temperature application is not a problem for graphite due to its dimensional stability under wide temperature variations and its low coefficient of thermal expansion. 

Furthermore, graphite is highly resistant to chemicals, corrosion and oxidation. FLSmidth graphite blocks are manufactured in highly specialised workshops using CNC equipment, which ensures high precision tolerance and a smooth surface finish.

Inlet cooling The inlet cooling system consists of a fan and a closed isolated ducting system to cool vital sealing components. The cooling air is distributed to the rear flange and the air casing attached to the kiln riser. The air will escape into the atmosphere.

Outlet cooling The outlet cooling system is separated into two independent systems – one for the kiln shell and nose ring cooling and one for the graphite cooling. The graphite cooling is designed to maintain the temperature of the graphite blocks below oxidization temperature and secures the flatness of the flanges.