The tube mill is widely used in building material industry for grinding various grades of clinker and raw materials calcined for cement. The tube mill has the advantages of high productivity, high adaptability to materials, high reduction ratio, etc.According to different structures, the tube mills can be divided into double-bin type and triple-bin type. According to discharge mode the tube mills can be divided into tail discharge type and center discharge type. According to drive mode, the tube mills can be divided into end drive and center drive. According to grinding technology, the tube mills can be divided into dry grinding and wet grinding. According to different types of structures, discharges, drives and grinding technologies, the tube mills can be divided into types of double-bin type and triple-bin, or tail discharge and center discharge, or end drive and center drive, or dry grinding and wet grinding.The tube mill is one of the conventional equipment manufactured by NHI with history close to 50 years since 1970s. Over hundred sets of tube mills had been manufactured by NHI, which had accumulated plenty of precious experiences in design and production for NHI. The structure of the equipment had been improved and upgraded continuously. For purposes of meeting demand of large-scale equipment in cement production plant, NHI had independently developed, designed and manufactured the large-scale tube mills with multiple sizes. The equipment has the characteristics of serialization, generalization and standardization, which can meet the demand in cement production line under 5000t/d.