聚烯烃装置双螺杆挤出机的技术发展

TECHNOLOGY DEVELOPMENT OF TWIN SCREW EXTRUDERS IN POLYOLEFIN PLANTS

国内聚烯烃装置中挤压造粒设备以双螺杆挤出机为主,分为全啮合同向旋转和非啮合异向旋转两类。目前国内绝大多数大型挤出机仍从国外引进,主要制造商包括德国科倍隆公司、日本制钢所和日本神户制钢所3家。每家制造商的设备因起源不同,各有各的特点。文章从历史最悠久的非啮合异向旋转双螺杆挤出机入手,对上述3家主要制造商的双螺杆挤出设备的技术发展进行了总结,详细介绍了熔融齿轮泵的应用,并简要分析了齿轮泵应用和能耗的关系。同时,简要介绍了国内主要应用机型的产能以及主电机功率等主要技术参数,并以全密度聚乙烯装置实际应用为例,对比了两种机型机组的稳定性。此外,还结合以往项目经验,介绍和分析了螺杆磨损筒体问题,以便为用户选择设计合理、性价比较佳的挤出造粒设备提供帮助。

The extrusion equipment in Chinese domestic polyolefin plants is dominated by twin screw extruders which are categorized as two types in actual application:wholly intermeshing co-rotating type and non-intermeshing counter-rotating type.Currently,in most domestic projects,the extruders are still imported from abroad from three main manufacturers including Coperion GmbH from Germany,the Japan Steel Works,Ltd.and Kobe Steel Ltd.from Japan.The different origin leads to a variety of characteristics.This paper summarizes the technological development of twin screw extrusion equipment from the aforementioned three main manufacturers by starting with the oldest non-meshing anisotropic rotary twin-screw extruders.It reviews the application of melt gear pump in detail and briefly analyzes the relationship between gear pump application and energy consumption.Meanwhile,the paper gives a general introduction to the main technical data,such as production and power of main drive,and compares the stability between the two types of the units with the actual application of full-density polyethylene plant as an example.Moreover,combined with previous project experience,the wear between extruder screws and barrels is introduced and analyzed so as to provide assistance to users in selecting well-designed extrusion equipment with better cost performance.