双转式双滚筒 contrarotating drum

双柱式转臂吊机 spearleg derrick

双锥回转式真空干燥机 double conic rotary vacuum dryer ; Double-cone revolving vacuum drying machine

翻转式双向犁 [农机] two-way alternative plow

双筒旋转式分流器 dual rotating diverter

双转换式 double conversion

双鼠笼式转子 double squirrel cage rotor

双转子摆式罗经 two-gyro pendulous gyrocompass