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浓度在纸张纵向定量控制中非常重要,浓度前馈控制在纸张质量大闭环控制中是最重要的一个环节。生产过程中各种扰动会造成不稳定,只有通过生产实践对浓度前馈控制参数进行整定和优化,才可以抑制扰动,定量纵向控制才可以投入大闭环自动控制,才可以确保纵向定量的稳定。本文对纸张纵向定量控制原理及影响控制的因素进行了分析,主要分析了浓度死... 相似文献
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QCS是针对造纸行业的连续运转、纸张指标波动大的特性而设计,对纸张进行的在线检测和控制纸张定量、水分、灰分、厚度的一套系统,以保证控制更稳定,测量更准确。本厂以ABB公司提供的QCS系统为基础,对纸张进行纵向控制。 相似文献
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造纸工艺中烘缸温度控制对纸张质量至关重要,电磁烘缸利用电磁感应加热技术干燥纸张,具有安全高效、加热均匀等优点.但烘缸温度控制系统是一个非线性、时滞性系统,且受外界因素干扰,纸张烘干过程中控制易变参数,传统的PID控制系统已无法满足烘缸温度控制要求.因此提出了一种基于模糊PID的电磁烘缸温度控制系统,旨在实现烘缸温度的精准控制,提高纸张生产质量. 相似文献
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纸张定量水分解耦及滞后控制策略的研究 总被引:1,自引:0,他引:1
针对造纸过程中纸张定量与水分之间存在严重耦合的问题,提出了一种基于神经网络的静态解耦方法,成功地将造纸过程的多变量系统变成了单变量系统,实现了定量、水分之间的解耦。同时由于造纸生产过程存在较大滞后,运用增益自适应补偿控制方案,有效地克服了滞后对控制系统稳定性和质量控制的影响。仿真结果表明该系统具有良好的控制效果。 相似文献
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《造纸科学与技术》2021,(1)
纸张定量控制在造纸工艺中至关重要,不仅关系到纸张的生产效率和质量,还关系到纸张制造企业的成本问题。为此,设计一种基于PSO优化PID的造纸定量控制系统。该系统通过粒子群算法优化PID控制器的三个控制参数,让PID控制效果达到最佳,然后将传感器采集到的纸浆浓度、流量与设定值相比较,最后利用优化后的PID控制器根据偏差值控制浆泵转速和稀释水阀出水流量,从而使造纸定量达到最优。结果表明:与传统PID的造纸定量控制系统相比,所设计系统应用下,造纸定量在46~50 g/m~2之间波动,满足了设置的控制精度目标,即生产工艺±5 g/m~2偏差规定要求,证明了系统的控制性能。 相似文献
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为实现纸制品生产环节中针对纸张重量的准确控制,提出了一套基于DCS控制技术的造纸定量监测系统,根据造纸干燥工艺的基本需求为该系统选配了称重传感器、浓度分析仪、水分传感器以及定量阀等核心器件,并通过TJ-QCS3000(V1.2)流量控制平台实时显示各部件当前所获取的各项监测数据。根据系统平台显示结果发现,定量监测系统能够精确控制纸张重量偏差,在提高纸张产品质量的同时合理降低浆料、电能、蒸气等资源的使用量,具有一定的应用价值。 相似文献
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Axel Gommel 《中华纸业》2006,27(6):36-38
流送系统设计新概念就是将影响流送系统质量的各因素整合到一个系统工程设计概念当中,为优化纸张质量尤其是改善纵/横向定量全幅分布打下基础。这包括使用MSA MultiScreen筛、EcoMizer除渣器、特殊工程设计部件、标准化设计指南、优化湿部控制等。 相似文献
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C. INTRIERI I. FILIPPETTI G. ALLEGRO M. CENTINARI S. PONI 《Australian Journal of Grape and Wine Research》2008,14(1):25-32
Background and Aims: The number of pre‐bloom source leaves is a primary determinant of subsequent fruitset. Accordingly, we tested whether pre‐ and post‐bloom hand (HD) and mechanical (MD) defoliation are effective in limiting the yield of a high‐cropping cultivar such as Sangiovese in a 3‐year field study. Methods and Results: The first six basal leaves and any laterals were removed by hand, and the same area was subjected to MD, the latter removing 48.3% of the leaf area removed manually. Both treatments significantly reduced fruitset, yield per shoot, bunch weight, berries per bunch and bunch compactness. Yield/ha declined from 32.8 tons in control vines to 24.4 and 19.0 tons for MD and HD (pre‐ and post‐bloom treatment means), respectively. Leaf‐to‐fruit ratios were unaffected by defoliation as source loss was fully offset by yield decline. Soluble solid concentration and total anthocyanins on a fresh‐weight basis increased by 2.4°Brix and 0.2 mg/g in HD and by 2.2°Brix and 0.08 mg/g in MD as compared with that in non‐defoliated control. Conclusions: Although results from HD reinforce the physiological basis of the technique's effectiveness, MD proved likewise effective in reducing yield and improving grape quality. Significance of the Study: Early MD has the potential to regulate yield in a timely and cost‐effective fashion. 相似文献
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通过二次回归通用旋转正交试验设计,应用响应面分析法对米渣水解蛋白-麦芽糊精(RRHP-MD)Maillard反应过程中的各反应条件进行分析,建立数学模型,优化反应条件参数,以求得到乳化活性(EA)佳的RRHP-MDMaillard反应共聚物。结果表明:在58℃,采用水解度(DH)为6的RRHP,保持其与MD的比例为8:1,pH为6.5,反应3d可以得到高乳化活性的反应共聚物。在此最佳反应条件下对反应共聚物的乳化活性进行了研究,证实了预测值和实测值是一致的。此时,反应物乳化活性比国外进口的酪朊酸钠还要好。 相似文献
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Grigorovich NV Moiseenko DV Antipova AS Anokhina MS Belyakova LE Polikarpov YN Korica N Semenova MG Baranov BA 《Food & function》2012,3(3):283-289
The sodium caseinate (SCN)-maltodextrin (MD) covalent conjugates were prepared by a food-grade process involving the first step of the Maillard reaction. The covalent conjugates were prepared with different weight ratios of biopolymers (R(MD?:?SCN) = 0.4; 1; 2; 5) in the system using maltodextrins of strongly different dextrose equivalents (DE), i.e., DE = 2 and 10. We have observed that the covalent conjugation of SCN with MD, in contrast to their simple mixing, improved the protein solubility in an aqueous medium in a wide pH range that was more pronounced in the vicinity of the SCN isoelectric point (pH 3.8-4.4). The extent of SCN solubility was mainly governed by the weight/molar ratio of the biopolymers in the covalent conjugates, R(MD?:?SCN). Data of static multiangle laser light scattering showed that the revealed increase in the solubility of the conjugates could be predominantly attributable to the dramatic increase in their thermodynamic affinity for an aqueous medium. Which was most pronounced for the maltodextrin with the higher DE (DE = 10). The direct relationship between the increase in the solubility of the conjugates and the increase in their foaming ability, as compared against SCN, has been revealed as a rule both at neutral pH and at the pI. In addition, the found improvement in the protein foaming ability was also defined by both the weight/molar ratio (R(MD?:?SCN)) and the dextrose equivalent of the maltodextrins attached to the protein. 相似文献
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介绍了孔板布浆导流短孤形板网槽的结构,并对其成形纸页性能进行测定,结果表明,这种网槽有较好的布浆成形性能,纸页横幅定量偏差较小,纵横向强度比较接近。 相似文献
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泰格林纸集团从芬兰Metso公司引进的优化概念机内涂布机(optiSizer)采用计量棒进行预计量膜涂布,在施涂辊辊面上形成的膜层十分均匀,还能进行涂布量的纵向与横向精确控制.本文介绍了该涂布机的结构特征与操作,涂布时工艺条件与涂布量的控制及调试运行情况. 相似文献