Composite crystallizer

The invention relates to a duplex type crystallizer which comprises a sliding type crystallizer which is taken as an upper crystallizer and a synchronous circulation mobile cooling belt device which is taken as a lower crystallizer. The duplex type crystallizer consists of the upper crystallizer and the lower crystallizer. The lower crystallizer consists of more than two cooling belts, a driven roller, a cooling device, a supporting roller and a driving roller, wherein, the driven roller and the driving roller are respectively positioned at the two ends of the cooling belt, the supporting roller and the cooling device are arranged between the driven roller and the driving roller, each cooling belt surrounds at the periphery of the driven roller, the cooling device, the supporting roller and the driving roller. The invention adopts the fractional crystallizer structure, the upper crystallizer only plays the role of shell-making, which can decrease the length and reduce the motion resistance of the casting blank; and no motion resistance exists between the lower crystallizer and the casting blank, thus lengthening the lower crystallizer and meeting the requirement of cooling the casting blank. The adoption of the duplex type crystallizer can promote the casting speed, improve the cooling capability, increase the productivity of a continuous casting machine and lower the occurrence possibility of accidents.