scholarly journals In-process detection of fiber cutting in low consistency refining based on measurement of forces on refiner bars

TAPPI Journal ◽  
2017 ◽  
Vol 16 (04) ◽  
pp. 189-199 ◽  
Author(s):  
R. Harirforoush ◽  
J. Olson ◽  
P. Wild
Keyword(s):  
Fiber Length ◽  
Scale Parameter ◽  
Threshold Value ◽  
Dominant Frequency ◽  
Sensor Data ◽  
Weibull Function ◽  
Pulp Fibers ◽  
Major Drawback ◽  
Normal Forces ◽  
Process Detection

A major drawback of low consistency refining is the degradation of mechanical properties due to fiber cutting at high refining energies. Conventional strategies to avoid fiber cutting are based on post-refining measurement of pulp properties and, typically, this does not enable rapid adjustment of refiner operation in response to the onset of fiber cutting. The objective of this study is to detect the onset of fiber cutting by using custom-designed piezoelectric force sensors that measure shear and normal forces applied to pulp fibers by the refiner bars. Trials are performed in an AIKAWA/Advanced Fiber Technologies Inc. 16-in. single-disc low consistency refiner. The trials are run using mechanical softwood SPF (spruce, pine, and fir) pulp with 378 ml CSF at 2.5% and 3.5% consistency at rotational speeds of 800 rpm, 1000 rpm, and 1200 rpm. Distributions of the peak normal and shear forces and peak coefficient of friction are determined for each operating condition, and a two-parameter Weibull function is fit to each of these distributions. The scale parameter, which is one of the key parameters of the Weibull function, is calculated, and length-weighted fiber length is plotted as a function of this parameter. The results show that the onset of fiber cutting consistently corresponds to a distinct transition in the plot of length-weighted fiber length versus scale parameter. This transition is believed to be caused by a fundamental transition in the fiber-bar interaction. Moreover, frequency analysis of the sensor data shows that the magnitude of the dominant frequency remains relatively constant while the plate gap is reduced, up to a threshold value, which corresponds to the onset of fiber cutting. These results suggest that these sensors have potential to be used for in-process detection of the onset of fiber cutting.

scholarly journals A novel algorithm to detect non-wear time from raw accelerometer data using deep convolutional neural networks

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shaheen Syed ◽  
Bente Morseth ◽  
Laila A. Hopstock ◽  
Alexander Horsch
Keyword(s):  
Threshold Value ◽  
Detection Algorithm ◽  
Classification Model ◽  
Type I ◽  
Accelerometer Data ◽  
Deep Convolutional Neural Networks ◽  
Major Drawback ◽  
Wear Time ◽  
Detection Algorithms ◽  
Type Ii Errors

AbstractTo date, non-wear detection algorithms commonly employ a 30, 60, or even 90 mins interval or window in which acceleration values need to be below a threshold value. A major drawback of such intervals is that they need to be long enough to prevent false positives (type I errors), while short enough to prevent false negatives (type II errors), which limits detecting both short and longer episodes of non-wear time. In this paper, we propose a novel non-wear detection algorithm that eliminates the need for an interval. Rather than inspecting acceleration within intervals, we explore acceleration right before and right after an episode of non-wear time. We trained a deep convolutional neural network that was able to infer non-wear time by detecting when the accelerometer was removed and when it was placed back on again. We evaluate our algorithm against several baseline and existing non-wear algorithms, and our algorithm achieves a perfect precision, a recall of 0.9962, and an F1 score of 0.9981, outperforming all evaluated algorithms. Although our algorithm was developed using patterns learned from a hip-worn accelerometer, we propose algorithmic steps that can easily be applied to a wrist-worn accelerometer and a retrained classification model.

scholarly journals New technology for developing a lightweight refiner plate for hardwood kraft pulp fibers

BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 9128-9142
Author(s):  
Byeong-Geol Min ◽  
Ji-Young Lee ◽  
Chul-Hwan Kim ◽  
See-Han Park ◽  
Min-Seok Lee ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Fiber Length ◽  
Kraft Pulp ◽  
New Technology ◽  
Strength Properties ◽  
Pulp Fibers ◽  
Low Intensity ◽  
Novel Technology ◽  
Draft Angle ◽  
Reducing Energy

Sand casting makes it difficult to manufacture a fine bar plate for low intensity refining. This study introduced a novel technology for manufacturing lightweight fine bar plates and compared the effects to traditional bar plates. The lightweight fine bar plate base was manufactured using a lightweight aluminum alloy and stainless-steel. Because the bars were inserted into the plate vertically without the draft angle, the stock throughput was improved by approximately 27% compared to the sand-casted bar plates. Additionally, the lightweight fine bar plate maximized internal and external fibrillation while minimizing fiber length loss. In conclusion, the lightweight fine bar plate was shown to be more effective in improving the strength properties of paper and reducing energy consumption.

scholarly journals Tensile Strength and Dispersibility of Pulp/Danufil Wet-Laid Hydroentangled Nonwovens

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3931
Author(s):  
Chao Deng ◽  
R. Hugh Gong ◽  
Chen Huang ◽  
Xing Zhang ◽  
Xiang-Yu Jin
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Fiber Length ◽  
Water Jet ◽  
Pulp Fibers ◽  
Wet Strength ◽  
Blend Ratio ◽  
Sewage Systems

Wet-laid hydroentangled nonwovens are widely used for disposable products, but these products generally do not have good dispersibility and can block sewage systems after being discarded into toilets. In this study, both pulp fibers and Danufil fibers are selected as we hypothesize that the high wet strength and striated surface of Danufil fibers would allow us to produce nonwovens with better dispersibility while having enough mechanical properties. The wet strength and dispersibility of nonwovens are systematically studied by investigating the influence of the fiber blend ratio, fiber length, and water jet pressure. The results indicate that the percent dispersion could be as high as 81.3% when the wet strength is higher than 4.8 N, which has been improved greatly comparing the percent dispersion of 67.6% reported before.

SmartEmoDetect: An Internet of Things Based Emotion Monitoring Wearable Technology for Drivers

2019 ◽  
Vol 16 (9) ◽  
pp. 3969-3973
Author(s):  
Jasleen Kaur ◽  
Neera Batra ◽  
Sonali Goyal
Keyword(s):  
Threshold Value ◽  
Emotional Reactions ◽  
Sensor Data ◽  
Stress Monitoring ◽  
The Road ◽  
Severe Accidents ◽  
Warning Message ◽  
Sensor Signals ◽  
The Government ◽  
On The Road

Negative emotional reactions are the major source of severe accidents on the road. In this paper, an IoT based wearable device is proposed that will estimate the four negative emotions (stress, anger, terror, sad) in the driver and hence would be helpful to prevent roadway disasters. An intelligent stress monitoring control system at the cloud to analyze the sensor signals and to make the decision based upon the variation received in the signals is proposed. This system can also be effective for the government bus drivers. An auditory output response is from buzzer and a warning message is displayed on the screen inside the vehicle. The continuously monitored real time sensor data in the form of graphs is displayed on the PC screen considered as a central server. When any of the sensor value exceeds predefined threshold value, the driver is considered to be in subconscious state and the break system will be implemented to stop the DC motor.

Indications of the onset of fiber cutting in low consistency refining using a refiner force sensor: The effect of pulp furnish

2018 ◽  
Vol 33 (1) ◽  
pp. 58-68 ◽  
Author(s):  
R. Harirforoush ◽  
J. Olson ◽  
P. Wild
Keyword(s):  
Fiber Quality ◽  
Force Sensor ◽  
Strength Properties ◽  
Thermomechanical Pulp ◽  
Pulp Fibers ◽  
Increase Energy Efficiency ◽  
Time Domain Signal ◽  
Softwood Kraft Pulp ◽  
The Time Domain ◽  
Process Detection

Abstract Detection of the onset of fiber cutting is beneficial in low consistency refining as it may prevent reduction of average fiber length, optimize fiber quality improvements by operating at gaps just wider than the critical gap, avoid decreasing the strength properties of paper, and increase energy efficiency. The objective of this study is to understand the effect of pulp furnish on measured bar forces and, more specifically, on the detection of fiber cutting. Bar forces, i. e. forces applied to pulp fibers by the refiner bars, are measured with a custom-designed piezoelectric force sensor. Trials were conducted with an AIKAWA 16-in. single-disc refiner using hemlock/balsam softwood thermomechanical pulp, SPF softwood thermomechanical pulp, northern bleached softwood kraft pulp, and aspen hardwood thermomechanical pulp at 3.0 to 3.5 % consistency at rotational speeds of 1200 and 1400 rpm. The power of the time domain signal of the measured forces is introduced as an indicator of the onset of fiber cutting. Our results show that this new fiber cutting metric is a sensitive and reliable metric for determination of fibre cutting for a range of pulp furnishes. The study suggests that the refiner force sensor has potential to be exploited for in-process detection of fiber cutting.

scholarly journals Excellent Performance of Earth Dams under Resonance Motion Using Isolator Damping Layer

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
Behrouz Gordan ◽  
Azlan Adnan
Keyword(s):  
Scale Parameter ◽  
Free Vibration Analysis ◽  
Dominant Frequency ◽  
Earth Dam ◽  
Soil Mechanic ◽  
Seismic Zone ◽  
River Sand ◽  
Earthquake Effect ◽  
Small Models ◽  
Thickness Layer

The effect of blanket layer using isolator damping layer (IDL) between river sand foundation and short embankment to remove damage under severe earthquake was investigated in the present study. In case of numerical analysis by ANSYS program, dominant frequency (DF) was computed by free vibration analysis. Soil mechanic tests for thirteen samples to design IDL formula were carried out. In terms of critical condition for earthquake effect such as resonance, five physical small models were tested using vibrator table under the dominant frequency with scale parameter 1/100. As a result, dam was significantly damaged without blanket layer IDL. In order to reduce damage, the best performance was observed using blanket layer (IDL) when this layer was expanded below the reservoir region. The reinforced thickness layer size is one-fourth of dam height. This method is a novel suggestion for earth dam design in seismic zone.

scholarly journals A simple model for the influence of push-morainal banks on the calving and stability of glacial tidewater termini

1998 ◽  
Vol 44 (146) ◽  
pp. 31-41 ◽  
Author(s):  
Mark P. Fischer ◽  
Ross D. Powell
Keyword(s):  
Simple Model ◽  
Threshold Value ◽  
Horizontal Shear ◽  
Short Term ◽  
Flow Rates ◽  
Normal Forces ◽  
Glacier Terminus ◽  
Glacier Advance ◽  
Restraining Force ◽  
Term Response

AbstractPush-morainal banks at the grounding lines of tidewater termini of temperate glaciers are the source of two types of restraining forces operating at the glacier terminus. Horizontal normal forces derive from the lateral support and transport of the bank of sediment at the terminus, whereas a horizontal shear force operates along the base of a bank pushed in front of an advancing glacier. The simple model we present suggests that bank-related restraining forces are significantly larger than the restraining force derived from the hydrostatic pressure of water adjacent to the submerged terminus of a glacier. During glacier advance, restraining forces continually increase, resulting in decreasing flow rates, glacier thickening and the eventual cessation of advance. During retreat, restraining forces continually decrease, resulting in increasing flow rates, glacier thinning and the potential for unstable, rapid, sustained retreat. The normal, seasonal, oscillatory advance retreat cycle of a glacier is moderated by restraining forces associated with push moraines. Unstable retreat is likely initiated when bank-related restraining forces fall below some threshold value during the seasonal retreat cycle. Calving is not a primary cause of glacier retreat, but is more likely a short-term response to increased flow rates. Increased flow rates result in glacier thinning and an approach toward buoyancy, both of which fluctuate seasonally in accordance with bank-related restraining forces.

scholarly journals Mechanical modification of softwood pulp fibers using a novel lightweight vertical bar plate

TAPPI Journal ◽  
2021 ◽  
Vol 20 (4) ◽  
pp. 241-251
Author(s):  
HO-GYUNG GU ◽  
BYUNG-GUL MIN ◽  
JI-YOUNG LEE ◽  
SEE-HAN PARK ◽  
MIN-SEOK LEE ◽  
...  
Keyword(s):  
Fiber Length ◽  
Base Material ◽  
High Wear Resistance ◽  
Steel Alloy ◽  
Light Weight ◽  
Pulp Fibers ◽  
Sand Cast ◽  
Softwood Pulp ◽  
Insertion Method ◽  
Draft Angle

Refiner plates made using sand casting have a draft angle, which results in a trapezoidal bar shape. These trapezoidal bar plates have a limited throughput compared to the vertical bar plates, and eventually the edges of the bars become dull, resulting in longer time to reach the target freeness and shorter service life. The new light-weight refiner plate with a bar insertion method into a plate base was developed by selecting an aluminium-based alloy as the plate base material and a stainless steel alloy with high wear resistance as the bar material. The light-weight plate with sharp bar edges was very effective in reducing refining energy by reaching the target freeness faster than the sand-cast bar plate. Finally, the lightweight sharp bar plate, which weighed only about half the weight of the cast bar plate, was expected to significantly contribute to easy replacement, improved paper quality, and larger throughput without excessive loss of fiber length.

The effect of fiber dimensions on fiber network activation and tensile strength

Holzforschung ◽  
2012 ◽  
Vol 66 (1) ◽  
Author(s):  
Iiro Pulkkinen ◽  
Ville Alopaeus
Keyword(s):  
Tensile Strength ◽  
Wall Thickness ◽  
Fiber Length ◽  
Fiber Quality ◽  
Pulp Fibers ◽  
Fiber Network ◽  
Network Activation ◽  
Fiber Wall ◽  
Technical Properties ◽  
Comparison Of The Results

Abstract The objective of this work was to check the fiber network activation parameter developed earlier by the authors for eucalypt pulp fibers to predict technical properties of paper. The fiber size analyses were performed with an optical fiber analyzer that applies 2D image analysis techniques on single fibers. The effects of fiber length, fiber width, fiber wall thickness, and fiber curl distributions on the quality potential of eucalypt fibers were evaluated. Fiber curl and fiber wall thickness based parameters were found to have a high potential for evaluation of eucalypt fiber quality. The variations in technical properties of paper were explained with differences in fiber wall thickness and fiber curl distributions. When the model was tested against industrial long fiber pulps, a further modification for fiber length was needed. The Page tensile strength model and the shear-lag theory were applied for comparison of the results obtained by the network activation model. With the approach presented in this article, the strength characteristics of hardwood and softwood pulps can be easily evaluated based on fiber geometry and water retention value.

Analysis of High Pressure Zone Attributes From Tactile Pressure Sensor Field Data

2014 ◽  
Author(s):  
Martin Richard ◽  
Rocky S. Taylor
Keyword(s):  
High Pressure ◽  
Indentation Test ◽  
Field Measurements ◽  
Tactile Sensor ◽  
Threshold Value ◽  
Companion Paper ◽  
Sensor Data ◽  
Pressure Zone ◽  
Pressure Threshold ◽  
High Pressure Zone

Tactile sensor data collected during the Japan Ocean Industries Association (JOIA) medium-scale field indentation test program provide detailed information about spatial and temporal distributions of contact pressures during ice crushing. The localization of contact into high pressure zones (hpzs) through which the majority of loads are transmitted to the structure is an important feature of these data. For all but the slowest interaction rates, non-simultaneous failure is observed, with linear distributions of hpzs comprising a total contact area on the order of 10% of the nominal interaction area (structure width × ice thickness). To improve understanding of the nature of individual hpzs during compressive ice failure, a new approach to analyzing tactile sensor data has been developed. Analysis algorithms developed for automatic hpz detection and tracking are discussed. Issues associated with pressure threshold value definition and selection are considered. Probabilistic descriptions of high pressure zone attributes based on analysis of JOIA field measurements are presented. The development of a probabilistic ice load model based on these hpz data is detailed in a companion paper.

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