Refractories

Checker Bricks

      Due to the exact thermotechnical calculation and rational placing of refractories in temperature zones favorable for them, the high operational service life of refractories is reached. This eliminates checker clogging by dust and slag (see Fig. 1), including checker-work with 20 mm channel diameter. This ensures the service life of hot stove up to 30 years without major repairs.

           

The shaftless hot stove has been in operation for 27 years and is in perfect condition up to now with no repairs.

The Nippon Steel Corporation and Kalugin JSC experts

 

                       (a)                                            (b)

Fig. 1 – Condition of the surfaces of silica checker bricks from the top courses of the checker-work of BF No.4, NTMK shaftless hot blast stove after 9 (a) and 27 years (b) of operation.

       The efficiency of utilization of the heat of combustion products, i.e. both the quantity of heat transferred to cold blast air as well as the temperature of hot blast, depend on the checker’s heat exchange surface area, on the heat exchange factor, on the accumulating weight of checker-work and its thermal and physical properties.

       The checker bricks in first Kalugin stoves were made, as in conventional hot blast stoves, of typical hexagonal checker bricks with 40 mm diameter channel (see Fig. 2,a). KALUGIN JSC designed new types of checker bricks for the new stoves to enhance their heating surface area and heat transfer factor:

a) With 40mm channel diameter and 32.7 ㎡/m³ heating suface - it is a standard checker brick in Russia

b) With 30mm channel diameter and 48 ㎡/m³  or 48.7㎡/m³ heating suface - this checker brick is applied in KSS

c) With 20mm channel diameter and 64㎡/m³ heating suface - it is also widely  applied in KSS

 

         

    (a)  d=40mm                        (b)   d=30mm                            (c) d=20mm

Fig. 2 – Checker bricks