卷烟制丝工艺质量控制外文文献.doc

西南科技大学本科生毕业论文卷烟制丝工艺质量控制10 制丝的工艺任务是按产品设计的要求，将不同等级、品种的烟叶（烟梗）和掺配物组成的叶组配方，通过相应的加工工序，利用蒸汽、水和气的综合作用，实现烟片（烟梗）的形状、尺寸、成分和性质的不断变化，生产出符合设计要求的卷烟产品。制丝是卷烟加工过程的一个重要环节，其加工水平的高低直接影响到卷烟内在质量的稳定与提高，对保证卷烟风格的稳定性以及在生产过程中的降耗都起到至关重要的作用。 一、制丝过程可控制的主要工艺参数 （1）松片回潮：滚筒式回潮机对出口物料的水分和温度进行开环控制，要保证出口物料的水分和温度的稳定，需要保证进滚筒物料的流量、蒸汽和水压的稳定，同时要考虑物料的本身的品质（水分、吸水性等）。本工序的指标控制采用开环控制，需要控制过程加水量、蒸汽施加量、滚筒筒体转速、热风温度、热风风量、排潮量等参数。 （2）润叶加料：采用压缩空气和蒸汽作为加料的动力，利用调节阀、流量计进行加料量的闭环控制，加料控制精度小于1.0%，可设定和修改进行pid调节的参数，主要控制的参数有来料流量、空压和温度。 （3）烘丝控制：采用蒸汽作为叶丝干燥的动力，利用调节阀、水分仪，对温度、水分进行闭环控制，水分控制精度0.5%以内，可设定和修改进行pid调节的参数。主要控制的参数有来料流量、筒体转速、筒体温度、蒸汽压力、热风温度、热风风量、排潮量等。 （4）超热气流干燥：采用热风作为叶丝干燥的动力。利用调节阀、水分仪、温度仪，对温度、水分进行闭环控制，水分控制精度0.8%以内，可设定和修改进行pid调节的参数。主要控制的参数有来料流量、热风温度、热风风量、来料水分等。 （5）加香：采用空压作为烟丝加香的动力。利用调节阀、流量计进行加香量的闭环控制，加香控制精度小于0.5%，可设定和修改进行pid调节的参数。主要控制的参数有来料流量、空压和加香比例等。 二、关键工序的控制模式分析 1、松片回潮工序 1）影响的控制参数及因素主要是前工序因素：来料的流量大小、流量均匀性、松散性（物料状况）、来料水分、原料吸湿性、吸热特性等。 2）工序控制参数：筒体转数、筒体角度、热风风量、风温、风湿、排潮量、加水量及水汽混合比例等。 3）评价工序质量的主要指标有：感官质量、松散率、水分、温度。 4）主要影响感官质量的因素是直接因素：蒸汽量与施加形式(强度)；间接因素：物料流量、温度、水分。 5）改进方向：稳定来料的流量以及保持物料状态的均匀性；增加前端水分仪参与过程水分控制；对影响感官质量的蒸汽量、加水量、热风温度、排潮量实施量的控制。 2、烟片加料工序控制系统分析 加料工序的控制主要对加料精度、加料热风温度的控制。加料系统的加料比例控制系统如图1所示，热风温度控制系统如图2所示。 1）影响的控制参数及因素主要是前工序因素：来料的流量大小、流量均匀性、松散性（物料状况）。 2）工序控制参数：筒体转数、筒体角度、热风风量、风温、排潮量、加料比例等。 3）评价工序质量的主要指标有：感官质量、加料精度、水分、温度。 4）主要影响感官质量的因素是直接因素：蒸汽量与施加形式(强度)、加料系统的稳定性；间接因素：物料流量、温度、水分。 5）改进方向：稳定来料的流量及物料状态的均匀性；对影响感官质量的蒸汽量、热风温度实施量的控制。 3、烘丝机控制系统分析 叶丝干燥主要通过烘丝机筒壁温度、热风温度和排潮量来实现叶丝水分的变化。烘丝机筒壁温度是叶丝干燥的主体热源，对卷烟的感官质量影响程度最大，同时筒壁温度作为叶丝干燥的控制因素，存在系统热惯性大，调节周期长，对干燥后控制指标（叶丝水分）调节周期缓慢，滞后性大，易造成筒壁温度的反复调整，引起物料出口水分大幅度波动，回复周期长，对卷烟的感官质量影响明显，因而筒壁温度不宜作为反馈控制变量。如固定烘丝机筒壁温度，选用热风温度或排潮量作为控制变量，从原理分析，热风温度一般在100左右，能快速带走物料中的水分。通过排潮量调节滚筒内环境温湿度，达到控制物料水分的目的。烘丝机筒壁温度一般在140左右，物料进入滚筒后，接触筒壁的物料会瞬时干燥，物料在搅拌过程中，滚筒内的环境温湿度起到平衡物料水分的作用。现行烘丝干燥系统控制系统如图3所示，排潮风门及热风控制系统如图4所示。 1）影响的控制参数及因素是前工序因素：来料的流量大小、流量均匀性、来料水分、温度。 2）工序控制参数：筒体转数、筒体角度、热风风量、风温、排潮量、滚筒筒壁温度等。 3）评价工序质量的主要指标有：感官质量、水分、温度。 4）主要影响感官质量的因素是直接因素：滚筒筒壁温度；间接因素：物料流量、温度、水分。 5）改进方向：对影响感官质量的滚筒筒壁温度定量控制，对热风温度或排潮量实施自动控制。 4、加香系统分析 由于烟丝在加香前，烟丝的温度比较低、脆性大，抗造碎能力不强，如增加喂料机控制烟丝流量，势必造成烟丝的消耗大幅度增加。所以，现行的加香工序前没有设置烟丝流量控制，势必造成烟丝流量波动大。由于加香系统采用比例跟踪控制模式，瞬时加香的流量是以烟丝流量为基准流量，基准流量（烟丝流量）的波动直接影响到加香精度。加香系统控制系统如图5所示。 1）影响的控制参数及因素是前工序因素：来料的流量大小、流量均匀性。 2）工序控制参数：筒体转数、筒体角度、空气压力、加香比例等。 3）评价工序质量的主要指标有：感官质量、加香精度。 4）主要影响感官质量的因素是直接因素：压缩空气压力、加香系统的稳定性；间接因素：物料流量、加香比例。 5）改进方向：稳定来料的流量；控制加香精度。 三、目前制丝过程可以进一步提高的方面 1、部分工序流量稳定性不足。流量稳定是保证制丝产品质量稳定的一个基本条件，流量的稳定是产品质量稳定的前提。由于控制调节系统具有滞后性，流量的波动直接造成相应工艺指标的波动，稳定流量是制丝线必须解决的问题。流量稳定包括加工物料的流量和技术指标（水、蒸汽、空压气等）的稳定。如烟松散工序，一方面是切片系统不稳定，另一方面是原料包件的不规范，给控制流量的稳定造成困难。 2、工艺参数的合适性有待提高。随着工艺技术的发展以及特色工艺技术的需求，工艺控制由结果控制向过程控制转变，过程控制主要对过程工艺参数的控制。现行的工艺参数部分不能完全适应产品质量稳定的需求，工艺技术部门的制定工艺参数范围比较宽，现场工艺可以在工艺技术部门的制定工艺参数范围内进行细化。如根据叶片贮存的时间，结合车间的环境温湿度的实际情况，在不违背工艺技术标准的前提下，适当调整前工序的质量指标，可为下道工序提供质量的保证。 3、执行工艺指标的严肃性。按要求执行工艺指标的前提是工艺指标必须符合生产实际，工艺指标要符合实际，要求工艺部门及时根据生产实际进行综合调整，这样可保证操作人员操作的规范性，避免生产过程工序参数无序的调整。 4、加强操作的规范性和统一性。每个班次每个操作人员的操作习惯和操作方式不尽相同，给产品批次之间质量的稳定带来隐患，由于操作习惯和操作方式的差异，必然导致过程控制指标的差异，制丝线很多质量问题不能直观的表现出来，从细节上加以控制，有利于产品质量的稳定。 5、加强工艺技术和设备的研究。设备是保证工艺质量的基础，设备的性能直接影响到产品的质量。随着时间的变化，设备的性能随之变化，如何保证设备性能发生变化的情况下，及时调整工艺技术参数，达到设备与工艺的完美的结合？首先，设备维修人员与工艺技术人员从观念上要有认同，认识到设备对工艺的影响以及对质量的影响。cigarette process quality control technological tasks silk is by product design requirements, different grades of recipe leaf varieties of tobacco (stem) and blending composed by corresponding processing steps, the use of steam, water and gas combined role in achieving smoke piece (stem) of changing the shape, size, composition and properties of production to meet the design requirements of cigarette products. silk cigarette is an important part of the process, which directly affects the level of processing to cigarette inherent quality and enhance the stability, to ensure the stability of the cigarette style and consumption in the production process have played a crucial role .first, the main technical parameters silk process can be controlled(1) loose piece resurgence: the resurgence of a drum machine to moisture and temperature at the outlet of material open loop control, to ensure stable export material moisture and temperature, the need to ensure that flow into the cylinder material, steam and water pressure is stable, at the same time to consider the quality of the material itself (moisture, water absorption, etc.). indicators of this process is controlled by open-loop control, the amount of water necessary to control the process, the amount applied, the drum cylinder speed, air temperature of hot air volume, exhaust steam parameters such as tidal volume.(2) runye feed: use of compressed air and steam as the primary control power feed, the use of regulating valves, flow meters for closed loop control feeding amount of feeding control accuracy of less than 1.0%, can set and modify the parameters of pid regulation, the parameters are the incoming flow, air pressure and temperature.(3) drying control: the use of steam as a power cut tobacco drying, by adjusting valve, water meter, temperature, moisture content in the closed-loop control, moisture control accuracy of 0.5%, can set and modify pid regulation parameters. the main control parameters are the incoming flow, cylinder speed, barrel temperature, vapor pressure, hot temperature, hot wind, tidal discharge amount.(4) the super-hot air drying: using hot air as the drying of silk leaves power. by adjusting valve, water meter, temperature meter, temperature, moisture content in the closed-loop control, moisture control accuracy of 0.8%, can set and modify pid regulation parameters. the main control parameters are the incoming flow, hot air temperature, the amount of hot air, incoming water and the like.(5) flavoring: using compressed air as the smoke of incense filament power. by adjusting valves, flow meters for closed-loop control of the amount of flavoring, perfuming control accuracy of less than 0.5%, you can set and modify pid regulation parameters. the main control parameters are incoming traffic, air and perfuming proportion.second, analysis of key process control mode1. loose piece resurgence step1) control parameters and factors affecting mainly the first step of factors: the size of the incoming flow, flow uniformity, loose (material condition), the incoming water, raw material moisture, heat characteristics.2) process control parameters: cylinder revolutions, cylinder angle, hot air flow, air temperature, rheumatism, pai tidal volume, add water and water vapor mixing ratio and so on.3) the main indicators of the quality of the evaluation process are: sensory quality, loose rate, moisture, temperature.factor 4) mainly affects the sensory quality of the direct factors: the amount of steam applied form (strength); indirect factors: material flow, temperature and moisture.5) the direction of improvement: a stable flow of incoming material and maintaining the uniformity of the state; to increase participation in the front-end moisture meter moisture control process; the impact on the sensory quality of the steam, add water, hot air temperature, moisture exhaust amount implement volume control.2, tobacco sheet feeding process control system analysisto control the feeding process of feeding mainly precision, control the feed air temperature. , the hot air temperature control system shown in figure 2 dosing systems feeding proportional control system shown in figure 1.1) control parameters and factors affecting mainly the first step of factors: the size of the incoming flow, flow uniformity, loose (material condition).2) process control parameters: cylinder revolutions, cylinder angle, hot air flow, air temperature, exhaust tidal volume, feeding proportion.3) the main indicators of the quality of the evaluation process are: sensory quality, precision feeding, moisture, temperature.factor 4) mainly affects the sensory quality of the direct factors: the amount of steam applied form (strength), stable feed system; indirect factors: material flow, temperature and moisture.5) the direction of improvement: a stable flow rate and uniformity of incoming material state; on the organoleptic quality of steam, hot air temperature to implement volume control.3, drying machine control systemcut tobacco drying achieved primarily through changes in leaf water drying wire barrel wall temperature, the hot air temperature and discharge tidal volume. drying cylinder wall temperature is a leaf silk dry body heat, cigarette maximum sensory quality impact, while the cylinder wall temperature as cut tobacco drying control factors, there is a system thermal inertia, long adjustment period, after drying control targets (leaf silk moisture) regulating cycle slow, hysteresis, it could easily lead to repeatedly adjust the temperature of the cylinder wall, causing the material outlet moisture fluctuations, long response period, the impact of cigarette sensory quality significantly, so the cylinder wall temperature should not be used as a feedback control variable. such as fixed drying barrel wall temperature, use hot air temperature or moisture exhaust volume as the control variable, from the principle of the analysis, the hot air temperature is generally about 100 , can quickly take away material in the water. volume control temperature and humidity inside the drum through the discharge tide, to control material moisture purposes. drying cylinder wall temperature is generally about 140 , after the material into the drum, the contact cylinder wall material will be instantaneous drying, the material in the mixing process, the drum temperature and humidity play a role in balancing the material moisture. drying existing drying system control system shown in figure 3, moisture exhaust damper and hot air control system shown in figure 4.1) control parameters and factors is the former process factors: the size of the incoming flow, flow uniformity, the incoming water temperature.2) process control parameters: cylinder revolutions, cylinder angle, hot air flow, air temperature, exhaust tidal volume, roll the cylinder wall temperature.3) the main indicators of the quality of the evaluation process are: sensory quality, moisture, temperature.factor 4) mainly affects the sensory quality is a direct factor: the drum cylinder wall temperature; indirect factors: material flow, temperature and moisture.5) the direction of improvement: on organoleptic quality of the drum cylinder wall temperature of quantitative control, the amount of hot air temperature or moisture exhaust implement automatic control.4. flavoring system analysissince flavored tobacco in front, tobacco temperature is relatively low, brittle, making anti-crushing capacity is not strong, such as increasing tobacco feeder traffic control, will inevitably result in a significant increase in tobacco consumption. therefore, the first step of the existing flavored tobacco flow control is not set, it will inevitably cause the tobacco flow fluctuations. since the flavoring system with proportional tracking control mode, the instantaneous flow rate based flavored tobacco traffic-based traffic flow volatility benchmark (tobacco flow) directly affects the perfuming accuracy. flavoring system control system shown in figure 5.1) control parameters and factors is the former process factors: the size of the incoming flow, flow uniformity.2) process control parameters: cylinder revolutions, cylinder angle, air pressure, perfuming proportion.3) the main indicators of the quality of the evaluation process are: sensory quality, flavored accuracy.factor 4) mainly affects the sensory quality is a direct factor: air pressure, increase the stability of incense systems; indirect factors: material flow, perfuming proportion.5) improving direction: stable incoming traffic; perfuming precision control.third, the present process can be further improved silk aspects1, part of the process flow insufficient stability. flow stability is to ensure stable product quality silk as a basic condition, the steady flow rate is stable quality of products. since the control and regulation systems with fluctuating lag, a direct result of fluctuations in the flow of the corresponding process indicators, steady flow rate is made filaments must be addressed. including processing materials flow steady flow and technical indicators (water, steam, compressed air, gas and other) stable. smoke loose step, one is sliced system instability, on the other hand is not standardized raw material of the package, to control the flow of steady difficult.2, the appropriateness of the process parameters to be improved. with the demand for technology development and the characteristics of technology, process control from the results of the control to change the process control, process control and main control of process parameters. the current portion of the process parameters can not fully meet the needs of product quality and stability, the development of the process parameters technology sector is wide, site process can be refined in the development of process parameters technology sector. the blade as storage time, combined with the actual situation of temperature and humidity workshop, without violating the premise of technology standards, appropriate adjustments before the process quality indicators, can provide quality assurance for the next process.3, the implementation process indicators of seriousness. required the implementation process indicators on the premise that the process indicators must comply with the actual production process indicators to meet the actual requirements and production departments in a timely manner in accordan