Parametric Design and Performance Characteristic of Isometric Curved Bar Plate Based on SEL and SSL

Huan Liu,Jixian Dong,Chuanwu Duan,Ruifan Yang,Xiya Guo,Bo Wang,Kai Qi,Lijie Qiao,Sha Wang 한국펄프·종이공학회 2019 펄프.종이기술 Vol.51 No.5

Curved bar plate is common used in the pulp refining, but its design method is rather vague due it complex shape. A design method of isometric curved bar plate using two main parameters, the starting point and bar angle of central curve, was proposed in this paper and the calculation of characterization parameters of specific edge load (SEL) and specific surface load (SSL) was described. Isometric curved bar plates designed by two methods, one with fixed starting point and various bar angles and another with fixed bar angle and various starting points, were analyzed by characterization parameters of SEL and SSL. It would be expected to design isometric curved bar plate by the first method and the SEL would be a useful refining intensity to measure it in actual refining, however, the refining characteristics of different isometric curved bar plates should be further studied. The study on the design of isometric curved bar plate would be conductive to the research of curved bar plate and rapid design of it.

Accuracy of the Different Calculation Methods of Specific Edge Load

LIU Huan,DONG Jixian,LUO Chong,DUAN Chuanwu,GUO Xiya,QI Kai,QIAO Lijie,ZHAO Zhiming 한국펄프·종이공학회 2020 펄프.종이기술 Vol.52 No.5

Effect of Combined Refining Plates with Different Bar Angles on Paper Properties during Mixed Pulp Refining

( Xiya Guo ),( Jixian Dong ),( Huan Liu ),( Chuanwu Duan ),( Ruifan Yang ),( Kai Qi ) 한국목재공학회 2020 목재공학 Vol.48 No.5

Pulp refining is the major way to alter the properties of fibers and formed paper. Different combinations of the bar profile of the rotor and stator during low consistency refining processes directly affect the properties of the paper. In this study, a mixture of softwood and hardwood pulp was refined by varying the bar angle of the stator while that of the rotor is fixed at 0°. The pulp samples were collected at different refining times. Then, the pulp and paper properties, such as beating degree, fiber external fibrillation, and tensile and tear indexes were measured to explore the effects of the combined refining plates at different bar angles on paper properties. The results of the experiment show that the combined refining plate of 0° and 5° recorded the most significant improvement in the pulp beating degree and fiber external fibrillation. This consequently increased the fiber bonding area, which in turn, improved both the tensile and the tear indexes of the paper. Also, the influence of the combined refining plates with a larger bar angle on the paper properties was weaker compared to that of smaller angles. This study not only provides ideas for the bar profile design but also improves the optimal selection of refining plates.

Refining Mechanism of Combined Refining Plates with Different Bar Angles

Xiya GUO,Jixian DONG,Huan LIU,Chuanwu DUAN,Ruifan Yang,Kai QI,Lingbo Kong 한국펄프·종이공학회 2020 펄프.종이기술 Vol.52 No.2

The refining plate is a key component of the disc refiner, which plays an important role in improving fiber morphology and its properties during pulp refining. In this study, the mixed pulps of bleached softwood and unbleached hardwood pulp was refined by the combined refining plates with different bar angles. Beating degree, fiber length, fiber width, fiber length distribution and fiber fibrillation were analyzed to explore the influences of different combinations of refining plates on the improvement of pulp and fiber properties. The results indicated that the combined refining plate of 0° and 5° had the more significant changes in fiber length distribution, beating degree and fiber morphology than that of the combined refining plate of 0° and 0° as refining proceeded. The influences of the combined refining plate of 0° and 39° on the fiber length components, beating degree and fiber morphology were weakest compared to the remaining two. This study is of positive significance for the design and the selection of refining plates.

Effect of Pulp Properties on the Power Consumption in Low Consistency Refining

( Huan Liu ),( Jixian Dong ),( Kai Qi ),( Xiya Guo ),( Ying Yan ),( Lijie Qiao ),( Chuanwu Duan ),( Zhiming Zhao ) 한국목재공학회 2020 목재공학 Vol.48 No.6

The power consumption in the low consistency (LC) refining is an important indicator for the optimal control of the process and it is composed of the net power and the no-load power. The refining efficiency and process characterization of LC refining are directly affected by power consumption. In this paper, the effect of pulp consistency and average fiber length on the power consumption and refining efficiency were studied through the LC refining trials conducted by an experimental disc refiner. It is found that the curve of power-gap clearance can be divided into constant power section, power reduction section, and power increase section. And the no-load power and the adjustable domain of loading applied by the refining plates will increase as the increase of pulp consistency, while the increase of net power is larger than that of no-load power which makes the increasing of refining efficiency. Meanwhile, the adjustable domain of loading applied by the refining plates can be slightly improved by increasing the average fiber length, but its effect on the no-load power in the LC refining process can be neglected. The study of power consumption in LC refining is of positive significance for the proper selection of pulp properties in LC refining, in-depth exploration of refining mechanism, and energy consumption reduction in refining.

No-Load Power of Disc Refiner in Low Consistency Refining

Huan LIU,Jixian DONG,Xiya GUO,Bo Wang,Qiao Lijie,Chuanwu DUAN,Kai QI,Lingbo Kong 한국펄프·종이공학회 2020 펄프.종이기술 Vol.52 No.2

Disc refiner is the key equipment in pulping and papermaking process, and the no-load power of disc refiner will directly affect the refining efficiency. So the refining efficiency and energy saving of the refining process will be promoted through theoretical and experimental study on it. In this paper, the measurement and the theoretical calculation method of the no-load power of disc refiner in low consistency refining were summarized. And the effects of pulp properties, control parameters and bar parameters of refining plate on no-load power were analyzed. The main research direction of the no-load power of disc refiner was proposed which has a positive significance on energy saving and pulp quality improvements of refining process.

Study on Fiber Cutting Performance of Isometric Straight Bar Plate with Different Bar Angle

Huan Liu,Jixian Dong,Xiya Guo,Chong Luo,Xiaohui Tian,Xiaojun Jiang,Sha Wang,Ruifan Yang,Chuanwu Duan,Bo Wang,Kai Qi 한국펄프·종이공학회 2019 펄프.종이기술 Vol.51 No.5

The refining plate is a direct-acting component of refiners in pulping, and the bar profile of it have a major impact on fiber cutting, which affects the paper forming and strength of the formed paper. In this paper, the fiber average length, the fiber length distribution, the original fiber cutting rate and adjacent fiber cutting rate of samples collected in different refining time are used to analyze the fiber cutting mechanism of the isometric straight bar refining plates with different bar angles. The results show that the fiber cutting performance of plates gradually decreases and the limit fiber cutting length of the plate increases with the increase of the bar angle which is opposite to the conclusion predicted by specific edge load (SEL). However, the fiber cutting action of plates is gradually weakened until the average fiber length is reduced to the limit cutting length of plates. Meanwhile, the cutting mechanism of the straight bar plates with different bar angles is different. The larger bar angle of plate, the lower fiber cutting rate and the adjacent cutting rate of which is basically kept constant during refining, while the adjacent cutting rate of smaller bar angle plate on fibers gradually decreases with refining and finally remains constant. The study on the cutting performance of different bar angle plates has positive significance for the selection and design of refining plates for different pulping process.