Double Roller Research Articles

"Influencing factors of double roll coating ratio of reconstituted tobacco by papermaking

To investigate and elucidate the influencing factors and laws of double-roll coating ratio (CR) for papermaking reconstituted tobacco and to assess the effectiveness of CR in characterizing the finished product’s hot water soluble (HWS) content, base sheet (BS) specimens of reconstituted tobacco with varying bone-dry basis weights and moisture contents were prepared. These sheets were then coated with different physical indices of coating liquids using a small double-roll coater at different sheet speeds. Subsequently, the CR and HWS content of the finished product were analyzed. The results showed that when the viscosity of the coating liquid was > 280 mPa·s, the moisture content of the BS should be maintained between 18% and 22%, and the speed of the BS should be > 120 m/min; when the viscosity of the coating liquid is < 280 mPa·s, the moisture content of the BS should be maintained between 14% and 18%, and the speed of the BS should be > 120 m/min, so that higher HWS can be obtained in finished products. The bone-dry basis weight of the BS should be kept between 40 and 60 g/m2. The suspension solid content of coating liquid should be < 9.5%.

Heat transport enhancement by rotating bottom endwall in a cylindrical Rayleigh–Bénard convection

Rotating thermal convection, commonly encountered in natural and industrial environments, is typically influenced by both buoyancy forces and boundary rotation. In this study, we conduct direct numerical simulations to explore the effect of rotating bottom on the flow structure and heat transport of Rayleigh–Bénard convection (RBC) in a cylindrical cavity. This cavity has a radius-to-height ratio of 1 and is filled with an incompressible fluid with a Prandtl number of 0.7. Our results show that the axisymmetric convection pattern, observed in RBC for Ra∈[4000,8000] without rotation, transitions into a double roll structure at low rotating speeds (ω), while for Ra≤4000, the pattern remains axisymmetric, independent of ω. We then focus on the impact of bottom rotation on heat transport in the axisymmetric regime. Based on the variation in the Nusselt number (Nu) with ω, two distinct regimes are identified: a convection-dominated regime at low ω, where Nu closely resembles that of standard RBC, and a rotation-dominated regime at high ω, where strong shear induced by the rotating bottom intensifies the meridional circulation, significantly boosting global heat flux. The critical rotating speed, ω*, marking the transition between these regimes, follows different power-law relations below and above the buoyant convection onset (Rac): ω*∼Ra−0.64 for Ra<Rac and ω*∼Ra0.33 for Ra>Rac. As ω increases, the exponents for Nu∼Raλ and Re∼Raγ evolve before converging to λ≈0.3 and γ=0.5, respectively. Scaling laws for Nu and Re as functions of ω and Ra in the rotation-dominated regime are finally derived: Nu∼Ra0.3ω0.64 and Re∼Ra0.5ω.

Double-Cannula Maneuver for the Double-Roll Configuration of Donor Descemet Membrane Outside Recipient Anterior Chamber During Descemet Membrane Endothelial Keratoplasty.

The purpose of this study was to present a new surgical technique to convert a single roll of Descemet membrane (DM) into a double roll using 2 cannulas in a balanced salt solution-filled Petri dish during DM endothelial keratoplasty. A single DM roll stained with trypan blue was placed in a balanced salt solution-filled Petri dish. Two cannulas (28G) were introduced from opposite ends of the single roll, inserted into the roll, and slowly spread apart to change the single roll into a double roll. The DM was aspirated into the modified Jones tube and loaded, maintaining a double-roll configuration with endothelium-down orientation in a bevel-up position. The modified Jones tube with the bevel down was inserted into the recipient anterior chamber through the main wound. The modified Jones tube was rotated to the bevel-up orientation. After checking the graft orientation, the DM was inserted into the recipient anterior chamber. The double-roll DM was easily unfolded by tapping the center of the cornea using a cannula. A 28G cannula was inserted under the DM, and the anterior chamber was filled with air. Three months after surgery, the patient's corrected visual acuity in the right eye was 6/7.5 and the endothelial cell count was 1095/mm2. The corneal thickness was 533 μm, and the cornea was clear. The double-cannula maneuver mechanically changes the single roll of the donor DM to a double roll outside the recipient anterior chamber, making DM unfolding easier and minimizing the risk of upside-down apposition of the donor DM.

An improved ensemble learning model-based strategy for fault diagnosis of lithium battery double roller press equipment

Abstract The production process of lithium batteries is intricate, involving the coordination of various types of equipment.The sta-bility and precision of double roller press equipment directly affect product performance. With the increasing global de-mand for green energy, the application of lithium batteries in electric vehicles and energy storage systems is expanding, which imposes higher requirements on the stability and quality of lithium battery production. It is an important topic to address the challenges brought about by the gradual intelligentization of double roller presses, such as the complexifica-tion of control systems and the diversification of fault reasons. This paper proposes an enhanced ensemble learning model-based fault diagnosis strategy for lithium battery double roller press equipment. Firstly, the K-nearest neighbors (KNN) algorithm is employed to handle missing data, combined with normalization and standardization methods to improve fea-ture processing, thereby enhancing data quality. Secondly, the Maximum Information Coefficient (MIC) algorithm is utilized to select features highly correlated with fault labels, combined with the Recursive Feature Elimination with Cross-Validation (RFECV) to further optimize feature selection, creating an optimal feature subset. Finally, a RXS-XGBoost model is constructed through the Stacking ensemble learning method, selecting Random Forest (RF), XGBoost, and Sup-port Vector Machines (SVM) as base learners, with XGBoost as the meta-learner. This ensemble approach aims to lever-age the complementary advantages of different algorithms, enhancing the accuracy and robustness of fault diagnosis. The experimental results demonstrate that this improved ensemble learning diagnostic strategy achieves an accuracy rate of up to 99.05%, which is significantly better than other fault diagnosis strategies. It not only effectively reduces the model's training complexity and the risk of overfitting but also significantly enhances the efficiency and precision of fault diagno-sis for lithium battery double roller press equipment.

The Marketing Strategy of Double Roll Coal Crushers in China

The Marketing Strategy of Double Roll Coal Crushers in China

Structure of the human systemic RNAi defective transmembrane protein 1 (hSIDT1) reveals the conformational flexibility of its lipid binding domain.

In Caenorhabditis elegans, inter-cellular transport of the small non-coding RNA causing systemic RNAi is mediated by the transmembrane protein SID1, encoded by the sid1 gene in the systemic RNAi defective (sid) loci. SID1 shares structural and sequence similarity with cholesterol uptake protein 1 (CHUP1) and is classified as a member of the ChUP family. Although systemic RNAi is not an evolutionarily conserved process, the sid gene products are found across the animal kingdom, suggesting the existence of other novel gene regulatory mechanisms mediated by small non-coding RNAs. Human homologs of sid gene products-hSIDT1 and hSIDT2-mediate contact-dependent lipophilic small non-coding dsRNA transport. Here, we report the structure of recombinant human SIDT1. We find that the extra-cytosolic domain of hSIDT1 adopts a double jelly roll fold, and the transmembrane domain exists as two modules-a flexible lipid binding domain and a rigid transmembrane domain core. Our structural analyses provide insights into the inherent conformational dynamics within the lipid binding domain in ChUP family members.

Structure of the human systemic RNAi defective transmembrane protein 1 (hSIDT1) reveals the conformational flexibility of its lipid binding domain.

In C. elegans, inter-cellular transport of the small non-coding RNA causing systemic RNA interference (RNAi) is mediated by the transmembrane protein SID1, encoded by the sid1 gene in the systemic RNA interference-defective (sid) loci. SID1 shares structural and sequence similarity with cholesterol uptake protein 1 (CHUP1) and is classified as a member of the cholesterol uptake family (ChUP). Although systemic RNAi is not an evolutionarily conserved process, the sid gene products are found across the animal kingdom, suggesting the existence of other novel gene regulatory mechanisms mediated by small non-coding RNAs. Human homologs of sid gene products - hSIDT1 and hSIDT2 - mediate contact-dependent lipophilic small non-coding dsRNA transport. Here, we report the structure of recombinant human SIDT1. We find that the extra-cytosolic domain (ECD) of hSIDT1 adopts a double jelly roll fold, and the transmembrane domain (TMD) exists as two modules - a flexible lipid binding domain (LBD) and a rigid TMD core. Our structural analyses provide insights into the inherent conformational dynamics within the lipid binding domain in cholesterol uptake (ChUP) family members.

A Deep Transfer Learning Model for the Fault Diagnosis of Double Roller Bearing Using Scattergram Filter Bank 1

In this study, a deep transfer learning model was developed using ResNet-101 architecture to diagnose double roller bearing defects. Vibration data were collected for three different load scenarios, including conditions without load, and for five different rotational speeds, ranging from 500 to 2500 RPM. Significantly, the speed condition of 2500 RPM has not previously been investigated, therefore offering a potential avenue for future investigations. This study offers a thorough examination of bearing conditions using multidirectional vibration data collected from accelerometers positioned in both vertical and horizontal orientations. In addition to transfer learning using ResNet-101, four additional models (VGG-16, VGG19, ResNet-18, and ResNet-50) were trained. Transfer learning using ResNet-101 consistently achieved the highest accuracy in all scenarios, with accuracy rates ranging from 90.78% to 99%. Scattergram Filter Bank 1 was used as the image input for training as a preprocessing method to enhance feature extraction. Research has effectively applied transfer learning to improve fault diagnosis accuracy, especially in limited data scenarios. This shows the capability of the method to differentiate between normal and faulty bearing conditions using signal-to-image transformation, emphasizing the potential of transfer learning to augment diagnostic performance in scenarios with limited training data.

Double roller negative stiffness mechanism seat suspension optimization design and vibration analysis

To further improve the vibration isolation performance of automobile seat suspension and the riding comfort of automobiles, this paper uses the double roller negative stiffness mechanism (NSM) to calculate the seat suspension with quasi-zero stiffness (QZS) characteristics. The influence of the structural parameters on the QZS characteristics is simulated and analyzed, and the structural parameters are optimized by the orthogonal design method. The effectiveness of the optimization was verified by analyzing the dynamic response of the seat suspension system. The results show that the natural frequency of the vibration isolation system of the seat suspension decreases, the vibration isolation band widens after the introduction of the double roller NSM, and the vibration isolation effect is improved under low-frequency excitation.

Numerical Study on Characteristic Positions and Transition of Flow Patterns in a Slab Continuous Casting Mold

The flow pattern in an opaque mold cannot be readily visible, and worker experience plays a major role in controlling it, even though it has a significant impact on slab quality in a continuous casting (CC) mold. An Eulerian–Eulerian two‐fluid model is used to comprehensively study the two‐phase flow of argon and molten steel in a slab CC mold. The positions of vortex centers in upper/lower recirculation zones and the impingement point of jet flow on the narrow face of mold are identified and their distribution is analyzed. The interactive effects of casting speed, argon flow rate, and immersion depth of the submerged entry nozzle (SEN) on the flow pattern inside the mold are revealed. 2D and 3D flow pattern regimes are plotted and the boundary lines and boundary surfaces are fit with exponential functions and ternary functions, respectively. To obtain a double roll flow in the slab CC mold investigated, the relation among argon flow rate (), casting speed (), and the immersion depth of the SEN () should satisfy, .

New insights into double roll crushing

Double roll crushing is a comminution principle that has already been deployed for more than 100 years. It is known for high throughputs of sometimes sticky materials such as overburden. However, its applicability for ore and hard rock processing has been underestimated in recent decades. The presented research results are suitable for drawing attention again for these applications to a robust and reliable group of comminution machines – the double roll crushers (DRC).The paper presents results of extensive investigations exploring the influences of compressive strength, roll peripheral speed, feed particle size distribution, and single large oversized lumps on throughput of a toothed double roll crusher. A pilot-scale crushing plant in a quarry was deployed to test the crusher with limestone, andesite, and diabase. It can be shown that, contrary to other crusher types, within the physical limits of the machine, the throughput of DRC is barely influenced by the feed material’s compressive strength, while the feed particle size distribution or even single oversize lumps in the feed may have a substantial impact.

Design and experimental research on the counter roll differential speed solid organic fertilizer crusher based on DEM

Because of the problems that the current solid organic fertilizer is easy to agglomerate in the fermentation and stacking process, the fertilizer efficiency is brutal to release, and the strip application is difficult to discharge, this paper proposes a solid organic fertilizer crushing strip application method combining propeller blades and differential double roll. This article clarified the structure or installation parameters of the double roll fertilizer crushing, paddle fertilizer screw and trench covering device. The simulation test of the fertilizer tank compares the performance of three paddle fertilizer transport devices' fertilizer crushing and fertilizer transport and selects the symmetrical arrangement of the paddle combination. The discrete element software is used to simulate the operation process of the solid organic fertilizer crushing strip, and the influence of the ditching and fertilizing shovel tip into the soil, entirely into the soil, and stable ditching complete operation process on the movement state of soil particles were analyzed. A quadratic orthogonal rotation test is designed, and the optimal parameter combination is obtained as follows: the operating speed of the machine is 6.37 km/h, the angle of the shovel tip is 72.83°, the angle of the overburden is 19.56°, and the coefficient of variation of the optimized fertilization uniformity is 9.30 %. Finally, The average coefficient of variation of fertilization uniformity in the ground spreading experiment and the field strip fertilization experiment is 11.32 % and 13.87 %, respectively; both experiments are close to the simulation results. The research results provided a new scheme and technical support for the broken strip application of solid organic fertilizer in cultivated land.

Study on the analysis of cotton ginning machine transmission system

India is the second ranked large cotton producing country of world. Separation of fibre and seed is initial process desired for converting cotton crop to any finished product. Mostly ginning machines are developed as per need and volume of work to be processed. Ginning machine is main processing tool between cotton producers and textile industries. Commonly machines using double roller are utilized in India. As per the need from time to time Indian farmers adopted tools and techniques to provide high-quality cotton to local and overseas textile mills, ginning machines are upgraded step by step to cope up the demands. Twin roller ginning machine needs to be further developed and enhanced so as to improve performance of textile industries. In this paper, the analysis is conducted for betterment of current design. Double roller gin is focused here using analytical analysis for force acting on gears while transmission of torque, as well as balancing of components and thrust force acting on the bearing that creates vibration in the complete ginning machine assembly. Innovative design aspects considered in this work are found to be very effective for improve of double rolling gin machine performance.

Design And Build A Double Roll Type Pecan Breaking Machine With A Power Of 0.5 Hp

Pecan is one of the spices that become an ingredient in the process of the food and cosmetic industry. The pecan separator machine is made to facilitate and speed up the process of breaking the pecan fruit in order to increase work efficiency in the hope that the machine can achieve high efficiency in the form of good fruit yields. The purpose of this pecan fruit separator machine is to help facilitate the community in processing pecan fruit to the maximum of its production, and the community can also increase the processing productivity of pecan fruit, which can improve the community's economy. The research method applied in this study is an experimental method, namely the initial stage of designing a double roll type pecan breaking machine using Auto CAD. Then build the machine in the workshop based on the design that has been done before. The stages passed are making design drawings in Auto CAD and analyzing the components used in the pecan breaking machine. Such components are the frame, inlet funnel, shaft, breaker roller, bearing and outlet funnel. From the results of the analysis, the motor power is 0.5 HP with a rotation of 1400 rpm. The belt length used from the calculation of the pulley size on the 3" machine and the pulley on the 10 breaking roll is 42". For breaking rollers the outer diameter of the roller = 120 mm, the inner diameter of the roller = 100 mm, and the length of the roller = 190 mm. The shaft on the drive motor is 24 mm in diameter. The shaft isestimated to be of S30C carbon steel with tensile strength = 48 kg/mm².

Development and Application of Asynchronous Roll Shifting Strategy of Double Attenuation Work Roll in Hot Rolling

In view of the problems of the violent crown fluctuation and unstable shape control in the endless rolling production line, the field measurement results show that the abnormal crown fluctuation is related to the shifting limit position of the work roll after the uneven wear occurs. For this reason, the asynchronous roll shifting strategy is developed, which has double attenuation of roll shifting amplitude and roll shifting step. By coupling the roll wear contour model, the roll thermal contour model and the rolls-strip integrated model, the strip crown calculation model of the whole rolling unit is established, and the causes of abnormal crown fluctuation are revealed theoretically. In addition, the simulation analysis of the important parameters of asynchronous roll shifting strategy of double attenuation working roll is made by using this model. The number of strips in a roll shifting cycle is found to be too large or too small, which is not benefited by the control of the strip crown stability due to the influence of roll wear and roll thermal crown. A rolling unit has many shifting cycles. When the roll shifting amplitude at the end of a rolling unit is smaller, which can make the amplitude difference between adjacent roll shifting cycles greater, it is easier to avoid the uneven edge wear area and to control the strip crown stability. The industrial test shows that the maximum crown fluctuation in a rolling unit decreases by 21.05%, and the maximum crown fluctuation of adjacent strips decreases by 28.57%, which significantly improves the stability of crown control.

Structural Design and Assessing of Recombinantly Expressed African Swine Fever Virus p72 Trimer in Saccharomyces cerevisiae.

In an effort to control the outbreak of the African Swine Fever Virus (ASFV), there is an urgent need to develop an effective method to prevent the pandemic, including vaccines and diagnostic methods. The major capsid protein of ASFV p72 (B646L), which forms a trimer with each monomer adopting a double jelly roll fold, is the main component of the virus particle and major antigen of ASFV. Thus, the p72 protein may be considered an antigen candidate for vaccine and diagnostic development. However, the development of ASFV p72 trimer for the industry application, including veterinary usage, faces unavoidable challenges: firstly, the low cost of the antigen production is required in vaccine and diagnostic application; and, secondly, whether produced antigen folds in its native conformation. Here, based on the information provided by the atomic structure of p72, we have successfully performed rational mutagenesis on p72 trimers and expressed it in Saccharomyces cerevisiae with high yields. The cryo-EM structure of recombinant expressed p72 trimer is determined at 4.18 Å in resolution. The correlation coefficient between this structure and the ASFV virus structure is 0.77, suggesting a highly similar fold of this trimer with the native protein on the virus particle.

Study on the Position Deviation between the Iron Roughneck’s Spin-Rollers and the Drilling Tool

The spinner mechanism is one of the main working mechanisms of the iron roughneck, which is used to realize the rapid screwing-in or screwing-out of the drill pipe thread. The main problems of the spinner mechanism and the existing solutions are analyzed in this paper, and the spinner mechanism driven by a single hydraulic cylinder and transmitted by a wedge plate is designed. The upper and lower drilling tools are not concentric and affect the spin effect when the spinner mechanism works, and to address this problem, the influence of deviation in different directions is analyzed, and it is proposed that the lateral position deviation of drilling tools is the key factor affecting the spin performance. The relationship between the position deviation of the spin-roller and the position deviation of the drilling tool is established and solved. A method to reduce the lateral position deviation of drilling tools is proposed, and the effectiveness of this method is verified by experiments. The analysis shows that a spinner mechanism with a single follow-up roller easily causes the lateral position deviation of the drilling tool; the deviation of the spin-roller increases with the increase of the lateral deviation of the drilling tool, and the increase of the longitudinal deviation is more obvious; and with the increase of the drilling tool’s diameter, the deviation increases further. The symmetrical double follow-up roller structure can effectively reduce the lateral deviation of drilling tools and spin-rollers and ensures centering performance and the realization of reliable spin.

ISO 8685 compliant contractual ship-loading export facility: bauxite sampling plant process design and equipment selection for chemical sampling

The paper discusses the process design and mass balance for the minimum and maximum design case to illustrate the ISO 8685 compliance of a 2-year-running barge loading payment station sampling plant. The plant samples -100 mm, export quality, bauxite material from a barge-loading conveyor delivering 10 kton/h at 5.4 m/s. The green field operation does not know the Coefficient of Variation or the Size Range Factor as required inputs to calculate the Number of Primary Increments and Minimum Gross Sample Mass required. Therefore, informed assumptions were made given performance data of a neighboring sampling system that is in operation for over a decade. Without the available variation and size factor data the ISO-compliant scheme design could not commence. Where this data is not available for green field projects, it poses a risk that plant designs may not be compliant where variabilities could exceed assumptions on the input parameters. The system is designed for various barge carrying capacities with lot size in mass. Operational quality assurance however requires samples more frequently and therefore sublot periods are 4 hourly time based. ISO 8685 compliance is achieved with sample increments taken at maximum throughputs and barge sizes to determine the time-based interval. At reduced throughputs, the fixed time interval regime results in the minimum ISO requirements to be exceeded and tied in well with client overall quality incentives. Primary sample increments from a tailored cross belt sampler are crushed automatically in the sampling plant to 25 mm and then to 6mm using two stages of double roll crushers. The sample is then subdivided through secondary and tertiary sampling to produce a composite 4-hourly chemical sample. The 4-hourly sublot samples are collected in an ergonomic 4-way carousel with each composite sample representing 1-hour barge loading production— allowing the client quality assurance insights into their blending facility performance.

Prediction on the three-dimensional spatial distribution of the number density of inclusions on the entire cross section of a steel continuous casting slab

In the current study, the LES turbulent model, heat transfer, solidification, species transport model, and discrete phase model (DPM) were coupled to investigate the three-dimensional transient flow, temperature, solidification, segregation, and inclusion transport during the slab continuous casting (CC) process. The number, size, and spatial distribution of inclusions on the entire cross section of the CC slab were successfully predicted using the coupled full solidification model, DPM, and capture criteria at the solidification front. The improved capture criteria that considering the primary dendrite arm spacing (PDAS), different forces acting on inclusions, and the critical capture speed, successfully eliminated the banded distribution characteristics of inclusions under the simple capture criterion. The prediction results were in good agreement with the detection results. Four accumulation zones of inclusions along the thickness of the CC slab were predicted, including the 1/4 thickness and 3/4 thickness from the loose side, and the layer beneath the surface of the CC slab. Two accumulation zones near the layer beneath the surface of the CC slab were issued from the double roll flow pattern in the CC strand. The probability of inclusions contacting the solidification front in the upper recirculation zone increased, increasing the entrapment rate. The accumulation zones near the 1/4 thickness and 3/4 thickness from the loose side were corresponded to the peak value of the Marangoni force on inclusions at the 1/4 thickness and 3/4 thickness from the loose side. The Marangoni force increased the probability of inclusions being pushed to the solidification front. In addition, the accumulation near the 1/4 thickness from the loose side became more severe as the diameter of the inclusions increased due to the buoyancy.

Intelligent Health Diagnosis of Lithium Battery Pole Double Rolling Equipment Driven by Hybrid BP Neural Network and Expert System

At present, the fault diagnosis methods of lithium battery pole rolling mill mostly rely on manual experience and the self-test function of mature control devices such as frequency converters and lack the ability of intelligent fault diagnosis for the whole equipment and the ability to evaluate the health state of the equipment during operation. To improve the intellectual health diagnosis ability of lithium battery pole double rolling mill equipment, starting from the structure and technology of lithium battery pole double rolling equipment, this paper analyzes its common fault types. It summarizes the shortcomings and common fault types of existing equipment. Then, we introduce fuzzy reasoning into the fault diagnosis method based on Expert Systems and establish the FEFDM of lithium battery pole double rolling equipment. Finally, we introduce the concept of health degree, effectively connect BP neural network and health degree through the fuzzy set, and establish an equipment operation health state evaluation method based on an improved BP Neural Network, which realizes the evaluation ability of the health state of double roller equipment. In addition, we use Extended Kalman Filtering (EKF) to clean the “dirty data” and filter out the Gaussian white noise from the signal. The health diagnosis method proposed in this paper can meet the ability to accurately locate and diagnose the fault of lithium battery pole double roller equipment and evaluate the health state of equipment operation and maintain the equipment in advance.