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设计总说明本次毕业设计的题目是年产6000 吨硬质聚氯乙烯化工用管车间工艺设计。这是基于目前化工用管的要求，对比于其他材质的管材，较优地选择了采用硬质PVC管材。基于使用条件、加工条件等因素的考虑，制定该管材的标准为管材压力等级 5kg/cm2，公称外径为200mm，管材长度为长度:5±0.05m，管材壁厚为 7.7mm。本次设计的大致脉络为：从绪论到配方及成型方法的描述，再从总工艺流程到挤出设备各部件参数设计与计算，确定了设备的选型，最后再由物料的衡算、能量的衡算到非车间的工艺设计完成，经济的核算和车间的整理，充实在本次计划中的内容充分完善起来。在绪论中，主要介绍了塑料管道的应用和生产现状，并从性能用途和经济角度，对几种常用的管材材料进行了比较，最终确定将硬质聚氯乙烯作为本设计的使用材料。同时，该章中明确了本设计的目的和意义， 以及设计规格， 并对设计中拟解决的问题进行了考虑。在配方设计中。首先阐述了配方中各组分的作用并介绍了各组分常用的原料。根据硬质聚氯乙烯的特点，结合化工用管材的物理力学性能等标准，进行较优的配方设计。在选择组分的过程中，除了需要满足管材的物理化学性能之外，还考虑了配方中各组分的相互作用，原料是否较为易取，价格是否合理等因素。确定各组分之间的份数比。最后，综合考虑，以列表的形式给出配方设计表。在成型方法选择一章中。介绍了硬质聚氯乙烯管材常用的成型方法。将注射成型和挤出成型法进行比较，并确定将挤出成型法作为本设计的成型方法。在本章的第二节中，着重介绍了挤出法的工作原理及其特点。对比双螺杆和单螺杆生产管材的优劣势以及特点，结合本设计的目的和要求，最终决定采用双螺杆挤出生产U-PVC管。在生产工艺一章中。首先，确定了本次设计的总流程，对生产流程进行必要的简述，并给出生产工艺的流程总图。其次，按按照生产流程顺序，依次对各生产工序进行介绍和设计。其主要包括成型料的准备过程、挤出成型过程以及定型包装过程等。应该说，挤出成型过程一节是该章的重点，本节中除了对于生产设备及工艺进行详述外，还对挤出成型用螺杆以及机头口模的各项参数进行详细的选取和设计，以符合设计要求。最后，根据螺杆和机头口模参数的选取求得最佳工作点，为设备选型和物料衡算部分提供选择依据。在设备选型一章中，结合本设计的生产工艺以及最佳工作点，为各个流程选取合适设备，并给出每一个设备的相关参数，如型号、功率和尺寸等。该参数可以为能量衡算、经济核算以及车间布置环节提供有力的依据。在物料衡算一章中，以质量守恒定律为基础对物料平衡进行计算。首先，确定物料衡算的计算基准，包括生产天数、生产时间以及各环节的损耗率等。其次，给出工艺流程简图后即可计算原料的消耗量以及产品的产量，生产过程中各阶段的消耗量以及组成等等。最后，给出原料消耗综合表，以此可以进行经济核算。总工艺流程中，参考相关文献，确定总生产流程及原料的预处理工艺图，并加以具体说明。参考塑料机械设计的标准，细化流程各步所需设备的技术参数以及机型等。通过物料衡算，确定了工作时间、主要设备的相应台数。同时，罗列出了各个过程中产量及损失和废品量，为设计所需的原料量提供了参考依据。在能量衡算一章中。首先给出了能量衡算的流程图，并对该能量传递过程进行必要的简述。其次，分别对于挤出成型系统以及机头口模部分进行能量计算，以此求出冷却水和冷冻水的用量。在本章的第二节中，依据生产过程顺序，对生产过程中所使用的设备一一进行功率计算，并给出总的电量损耗。本章末尾处给出了能量损耗的综合表。该表可以为经济核算提供依据。在能量换算的内容里，通过挤出成型机和模具部分能量衡算的计算，得到冷却水和冷冻水用量，并且进一步确定具体用量。同时得出此次设计的耗电量。在车间非工艺设计一章中，对车间人员的人数及其岗位进行了简要的安排。同时，也考虑了车间安全环保方面的问题，包括采暖、通风和三废治理等。在以原料消耗表、能量消耗表以及设备综合表为依据的前提下，综合考虑其他因素，对本设计的成本进行了估算，估算的结果可以作为本设计合理性的评判条件。设计最后车间布置的内容，简单介绍了车间布置的要求与原则。结合设备选型以及生产工艺流程对车间进行布置，对此次设计的具体车间编排作了简要说明。其结果以车间布置平面图的形式呈现。57142
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Gross instruction of designThe subject of this graduation project is to design the workshop process of 6000 tonsU-PVC chemical pipe,which is based on the demand of pipe used for chemicalindustry.Compared to the pipe made of other material,U-PVC pipe is adopted as the optimumchoice.Based on conditions of use,processing conditions and other factors toconsider,standards for the pipe were developed in which the pipe pressure rating is5kg/cm2,nominal diameter is 200mm,tube length is 5±0.05m,pipe wall thickness of 7.7mm.The general contexts of this design are from the introduction to the description of theformulation and molding methods,and then from the general process to the design andcalculation of parameters in each extrusion components,and the decision of devicesmodel.And finally by the material balance,energy balance,non-plant technology,economicaccounting and plant layout,the contents of design were designed to fully perfect step by step.The first chapter is an introduction that introduces the applications and production statusof plastic pipe, and compares several common pipe materials from the performance andeconomy perspective, U-PVC was chosen as an optimal material for this design.The objectiveand significance of this design was also defined here.Finally,the problems to be solved weretaken into account in this section.In the design of recipe,The effect of every ingredients in the recipe was elaboratedfirstly,and then the common materials were given in every ingredient for comparison so thatwe could make a better choice.Combined with the properties of U-PVC,the optimum recipedesign was presented according to the standers for physical and mechanical performance ofpipes.When selecting the ingredients,the interaction among them is also a key factor,andwhether the materials is easy to get or not and the cost performance need to be considered aswell.Then the proportion of the ingredients should be determined.In the end,we could presentthe result as a list after Synthesizing each kind of factor.In the chapter of determination of molding methods.The common molding methods ofU-PVC pipe at home and abroad were recommended comprehensively.Injection Molding andextrusion molding are compared,and finally extrusion molding is chosen as the optimummethod to process U-PVC pipes.The second section highlights the working fundamentals andcharacteristics of extrusion molding.Combined with proposed target,and designingrequirements,twin-screw extrusion U-PVC pipe was ultimately decided through thecomparison of the advantages and disadvantages for single and twin screw pipe production process.In the chapter of general process,the main production process was given at the beginningof this chapter,and the necessary brief introduction was given to this process,then the processflow diagrams could be determined.Secondly,production working procedure is recommendand designed in sequence based on the processing order,including molding compoundpreparation process,extrusion process and packing process.The key point in this chapter is todesign the extrusion process.Each parameters of screw,die and extrusion head might beselected and designed in detail for design request.Finally,as an important foundation forequipment selection and material balance,optimal operating point could be figured out on thebasis of parameters of screw,die and extrusion head.In the chapter of equipment selection, selection of appropriate equipment for eachprocess procedure would be determined, combined with Production Process and optimaloperating.The revelant parameters for each equipment are also required,which lay the solidfoundation for next energy balance,economic accounting and Workshop layout.In the chapter of material balance,material balance could be calculated with the law ofconservation of mass.First of all,such calculation criterion as production day,production timeand attrition rate in every part should be determined.Secondly,the consumption of rawmaterial,and the production of products could be figured out with the consideration of Processschematic drawings.In the end,the amount of Raw material consumption could be listed sothat we can take up economic calculation.In the chapter of energy balance.The flow chart of energy balance,together withnecessary description of the energy transfer process was given at the beginning of thischapter.The amount of cooling water and chilled water was decided through the energycalculation of the extruder and mold,further,the specific amount of power consumption in thedesign was determined.Secondly,the amount of cooling water and chilled water was decidedthrough the energy calculation of the extruder and mold,further,the specific amount of powerconsumption in the design was determined.In the second section of this chapter, according tothe production process,Total power could be sumed from each equipment power,and the list ofenergy loss was given at the end of this chapter,which could support next economicaccounting.In the Non-process design, the staff arrangements and other related matters werelisted.Meanwhile,some security and environmental protection problem,such asheating,ventilating ,and "three wastes" treatment were also taken into account.Combined with other factors that have influences on cost,the total cost of the design was estimated on thebasis of the table of raw material consumption,energy consumption,and this result can judgewhether the design is reasonable or not.The plant layout design was the final content, in which the principles and requirements ofplant layout were briefly introduced. And the specific arrangement of the workshop in thedesign was illustrated.The result of plant layout design was presented as a floor-plan in theend.