NOVELTY - Sludge drying device utilizing radiation heat of rotary kiln of cement factory, comprises a sludge feeding device (1), a first and a second scraper conveyer (2, 11), a cement rotary kiln (3), a first and a second supporting wheel (4, 12), a first and a second sealing box feeding hole (5, 13), a first and a second sealing box, a first and a second crawler conveyer, a fixing rolling spike-tooth harrow, a first sealing box material exit, a first and second ventilation hole, a sealing box material exit, a cement rotary kiln drive device, a third supporting wheel, a material discharging conveyer.    USE - Used as a sludge drying device.    ADVANTAGE - The sludge drying device: utilizes the radiant heat of cement rotary kiln to dry the sludge at a low temperature and thus is cost effective. The dried sludge is used as auxiliary material of cement and contributes to the heat value during cement calcining.    DETAILED DESCRIPTION - Sludge drying device utilizing radiation heat of rotary kiln of cement factory, comprises a sludge feeding device (1), a first and a second scraper conveyer (2, 11), a cement rotary kiln (3), a first and a second supporting wheel (4, 12), a first and a second sealing box feeding hole (5, 13), a first and a second sealing box, a first and a second crawler conveyer, a fixing rolling spike-tooth harrow, a first sealing box material exit, a first and a second ventilation hole, a sealing box material exit, a cement rotary kiln drive device, a third supporting wheel, a material discharging conveyer, a first and a second drive device, a first and a second ventilation pipe, an exhaust fan and a biological filter tank. The cement rotary kiln is connected with the cement rotary kiln drive device. The head part, the middle part and the tail part of the cement rotary kiln are respectively provided with the first, second and the third supporting wheel. The first sealing box is arranged between the position under the first supporting wheel and the second supporting wheel of the cement rotary kiln. The first crawler conveyer is connected with the first drive device. One side of the first sealing box near the first supporting wheel is provided with the first sealing box material exit. The first ventilation hole is arranged on the first sealing box material exit. The first ventilation hole, the first ventilation pipe, the exhaust fan and the biological filter tank are connected with each other in turn. The exhaust fan is connected with the biological filter tank by the first ventilation hole and the first ventilation pipe. The second sealing box is arranged on the position between the second supporting wheel and the third supporting wheel of the rotary kiln of the cement factory. The inner side of the second sealing box is provided with the second crawler conveyer. The second crawler conveyer is connected with the second drive device. One side of the second sealing box near to the second supporting wheel is provided with the second sealing box feeding hole. One side of the second sealing box near to the third supporting wheel is provided with the second sealing box material exit. The second ventilation hole is arranged on the second sealing box material exit. The second ventilation hole, the second ventilation pipe, the exhaust fan and the biological filter tank are connected with each other in turn. The exhaust fan is connected with the biological filter tank by the second ventilation hole and the second ventilation pipe.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic representation of a sludge drying device.    Sludge feeding device (1)    First and second scraper conveyer (2, 11)    Cement rotary kiln (3)    First and second supporting wheel (4, 12)    First and second sealing box feeding hole (5, 13)