Spraying starch on the Fourdrinier— An option between wet end starch and the size press

TAPPI Journal ◽  
2021 ◽  
Vol 20 (1) ◽  
pp. 21-26
Author(s):  
COLE PRICE ◽  
MARTIN A. HUBBE
Keyword(s):  
Bonding Strength ◽  
Fiber Suspension ◽  
Paper Machine ◽  
Drying Process ◽  
Starch Solution ◽  
Paper Drying ◽  
Starch Grains ◽  
Wet Surface ◽  
Recycled Fibers

Technology to apply suspensions of starch grains to the wet surface of paper, during the dewatering process, is reviewed. Though the technology is not new, it continues to attract the attention of papermakers as a means to increase bonding strength. Starch grains that are sprayed onto the wet-web of paper can be retained at levels exceeding what can be effectively added to the fiber suspension at the wet end. Unlike adding a starch solution at a size press, no additional drying capacity is required on the paper machine. To be effective, the starch needs to be able to swell and develop bonding during the paper drying process. Paperboard applications with recycled fibers appear to be a good fit. There is potential to increase bonding by processes that favor fuller gelatinization of the starch grains by the time the paper becomes dry.

Microstructure simulation of early paper forming using immersed boundary methods

TAPPI Journal ◽  
2011 ◽  
Vol 11 (11) ◽  
pp. 23-30 ◽  
Author(s):  
ANDREAS MARK ◽  
ERIK SVENNING ◽  
ROBERT RUNDQVIST ◽  
FREDRIK EDELVIK ◽  
ERIK GLATT ◽  
...  
Keyword(s):  
Early Paper ◽  
Contact Model ◽  
Fiber Suspension ◽  
Beam Equation ◽  
Immersed Boundary ◽  
Paper Machine ◽  
Immersed Boundary Methods ◽  
Element Discretization ◽  
Microstructure Simulation ◽  
Boundary Methods

Paper forming is the first step in the paper machine where a fiber suspension leaves the headbox and flows through a forming fabric. Complex physical phenomena occur as the paper forms, during which fibers, fillers, fines, and chemicals added to the suspension interact. Understanding this process is important for the development of improved paper products because the configuration of the fibers during this step greatly influences the final paper quality. Because the effective paper properties depend on the microstructure of the fiber web, a continuum model is inadequate to explain the process and the properties of each fiber need to be accounted for in simulations. This study describes a new framework for microstructure simulation of early paper forming. The simulation framework includes a Navier-Stokes solver and immersed boundary methods to resolve the flow around the fibers. The fibers were modeled with a finite element discretization of the Euler-Bernoulli beam equation in a co-rotational formulation. The contact model is based on a penalty method and includes friction and elastic and inelastic collisions. We validated the fiber model and the contact model against demanding test cases from the literature, with excellent results. The fluid-structure interaction in the model was examined by simulating an elastic beam oscillating in a cross flow. We also simulated early paper formation to demonstrate the potential of the proposed framework.

Modeling of Energy-Saving Optimization Model by Sub-Sheet Dryness Coordination Based on Muti-Agent

2011 ◽  
Vol 347-353 ◽  
pp. 3171-3174
Author(s):  
Ding Hua Zhang ◽  
Huan Bin Liu ◽  
Ji Geng Li
Keyword(s):  
Energy Consumption ◽  
Energy Balance ◽  
Network Topology ◽  
Optimization Model ◽  
Optimal Algorithms ◽  
Drying Process ◽  
Paper Drying ◽  
Contract Net ◽  
Linear Complementary Problem ◽  
Multi Agent

According to Multi-Agent network topology of the globe energy node in papermaking dryer section, the optimal algorithms of each part of sheet for energy consumption node Agent is designed through the mentality of designing. And multi-Agent contract net protocol is improved based on the gambling solution of mixed linear complementary problem. The overall steam saving optimization can be achieved by coordinated and local optimization and globe energy balance of each energy node for the four group of paper drying process.

Investigation of Flashing Flow in a Siphon to Extract Condensate in Paper Dryer Application

2019 ◽  
Author(s):  
Hamed Abdul Majeed ◽  
Ting Wang
Keyword(s):  
Cfd Simulation ◽  
Paper Industry ◽  
Volume Ratio ◽  
Piping System ◽  
Drying Process ◽  
Local Pressure ◽  
Steam Consumption ◽  
Paper Drying ◽  
Computational Fluid Dynamics Cfd ◽  
State Case

Abstract The paper industry uses steam to dry paper web through cylinder dryers. As steam condenses inside the cylinder dryer, the condensate is removed by means of either a stationary or a rotary siphon. However, during the siphoning process for transporting the condensate, flashing of the condensate occurs, which could cause backflow or discontinuity in the siphoning process. To resolve this flashing issue, two approaches have been employed: (a) increasing the amount of steam supplied to the cylinder to “blow-through” the stalled condensate-steam mixture and (b) reducing the back pressure by inducing “suction” through a thermocompressor from downstream. This practice of employing push from the upstream and suction from the downstream requires excessively large amounts of high-grade steam, resulting in an estimated 10 to 15 %, 15 to 25%, and 40 to 90 % of blow-through steam for stationary siphons, rotary siphons, and Yankee dryers respectively. The objective of this study is to investigate and improve understanding of the flashing phenomena during condensate transport through the siphon and piping system in order to develop means to reduce this excessive steam consumption during the paper drying process. A computational fluid dynamics (CFD) simulation is performed that uses the Eulerian-Eulerian multiphase method. The steady-state case is first solved to obtain the flow field without flashing. Then the transient method is initiated by employing flashing and condensation models. The results show that reduction of local pressure triggers flashing, however, flashing in turn reduces local temperature, and subsequently induces condensation, resulting in an alternating flashing and condensation behavior. To maintain continuity of the siphon flow, the inlet pressure fluctuates corresponding to the variation of total vapor volume ratio inside the siphon. The results will be used to modify the current siphon system design and operating practices to reduce steam consumption.

Study on Paper Electromagnetic Drying Rate

2013 ◽  
Vol 680 ◽  
pp. 356-359
Author(s):  
Zheng Shun Wang ◽  
Zhao Hui Zhen
Keyword(s):  
High Speed ◽  
Energy Crisis ◽  
Drying Rate ◽  
Paper Machine ◽  
Paper Drying ◽  
Developmental Potential ◽  
Toilet Paper ◽  
Drying Technology ◽  
Steam Drying ◽  
Special Meaning

Paper electromagnetic drying technology is a new paper drying technology different from traditional steam drying. Today, environmental pressure deteriorating, energy crisis approaching, doing researches on paper electromagnetic drying technology has a special meaning, especially to high speed toilet paper machine which is truly needed and has a vast developmental potential. This thesis is based on electromagnetic dryer and steam dryer study. And the changes measured in the experiment at diverse temperatures and quantities in the experiment has shown a higher efficiency of electromagnetic drying technology than conventional steam drying technology.

Fundamental understanding of removal of liquid thin film trapped between fibers in the paper drying process: A microscopic approach

TAPPI Journal ◽  
2020 ◽  
Vol 19 (5) ◽  
pp. 249-258
Author(s):  
ZAHRA NOORI ◽  
JAMAL S. YAGOOBI ◽  
BURT S. TILLEY
Keyword(s):  
Thin Film ◽  
Liquid Film ◽  
Thin Liquid Film ◽  
Bound Water ◽  
Free Water ◽  
Intermediate Stage ◽  
Convective Drying ◽  
Drying Process ◽  
Paper Drying ◽  
Vof Model

In the fabrication of paper, a slurry with cellulose fibers and other matter is drained, pressed, and dried. The latter step requires considerable energy consumption. In the structure of wet paper, there are two differ-ent types of water: free water and bound water. Free water can be removed most effectively. However, removing bound water consumes a large portion of energy during the process. The focus of this paper is on the intermediate stage of the drying process, from free water toward bound water where the remaining free water is present on the surfaces of the fibers in the form of a liquid film. For simplicity, the drying process considered in this study corresponds to pure convective drying through the paper sheet. The physics of removing a thin liquid film trapped between fibers in the paper drying process is explored. The film is assumed to be incompressible, viscous, and subject to evaporation, thermocapillarity, and surface tension. By using a volume of fluid (VOF) model, the effect of the previously mentioned parameters on drying behavior of the thin film is investigated.

scholarly journals Nonlinear Modeling of Moisture Control of Drying Process in Paper Machine

2012 ◽  
Vol 38 ◽  
pp. 1104-1111 ◽  
Author(s):  
C. Karthik ◽  
K. Valarmathi ◽  
M. Rajalakshmi
Keyword(s):  
Nonlinear Modeling ◽  
Paper Machine ◽  
Drying Process ◽  
Moisture Control

Energy system diagnosis of paper-drying process, Part 1: Energy performance assessment

2015 ◽  
Vol 34 (8) ◽  
pp. 930-943 ◽  
Author(s):  
Xiaobin Chen ◽  
Jigeng Li ◽  
Huanbin Liu ◽  
Yongjun Yin ◽  
Mengna Hong ◽  
...  
Keyword(s):  
Performance Assessment ◽  
Energy System ◽  
Energy Performance ◽  
Drying Process ◽  
Paper Drying ◽  
System Diagnosis

scholarly journals Application of spruce wood flour as a cellulosic-based wood additive for recycled paper applications— A pilot paper machine study

TAPPI Journal ◽  
2021 ◽  
Vol 20 (10) ◽  
pp. 641-652
Author(s):  
KLAUS DOLLE ◽  
SANDRO ZIER
Keyword(s):  
Wood Flour ◽  
Strength Properties ◽  
Raw Material ◽  
Paper Machine ◽  
Particle Size Range ◽  
Recycled Paper ◽  
Spruce Wood ◽  
Recycled Fiber ◽  
Recycled Fibers ◽  
Machine Strength

This study gives a first insight into the use of wood flour as a plant-based and cellulosic-based alter-native additive for newsprint and paperboard production using 100% recycled fibers as a raw material. The study compares four varieties of a spruce wood flour product serving as cellulosic-based additives at addition rates of 2%, 4%, and 6% during operation of a 12-in. laboratory pilot paper machine. Strength properties of the produced newsprint and linerboard products were analyzed. Results suggested that spruce wood flour as a cellulosic-based additive represents a promising approach for improving physical properties of paper and linerboard products made from 100% recycled fiber content. This study shows that wood flour pretreated with a plant-based polysaccharide and untreated spruce wood flour product with a particle size range of 20 μm to 40 μm and 40 μm to 70 μm can increase the bulk and tensile properties in newsprint and linerboard applications.

Genetic Algorithm-Based Optimization of Steam Consumption of Dryer Section in Paper Machine

2014 ◽  
Vol 472 ◽  
pp. 180-184 ◽  
Author(s):  
Wei Tang ◽  
Yang Zhou ◽  
Wen Tao Gan
Keyword(s):  
Genetic Algorithm ◽  
Objective Function ◽  
Air Temperature ◽  
Great Influence ◽  
Paper Machine ◽  
Drying Process ◽  
Steam Consumption ◽  
Key Factor ◽  
Method Optimization ◽  
Simulation Results

In paper dryer section of the paper machine, paper dehydration is small, but the steam consumption for the process of dehydration is very large, this steam consumption has a great influence to the total steam consumption of the whole papermaking process. A method optimization of the dryer section based on genetic algorithm is proposed to reduce the dryer section steam consumption, which can reduce the total steam consumption of the papermaking process. After analyzing steam consumption of the whole drying process, the result is that the temperature of dryer section air is the key factor that influences the steam consumption. The model of paper machine dryer section is build with supply air temperature as a variable and steam consumption as the objective function, then using the genetic algorithm to optimize the supply air temperature. Simulation results show that after optimizing air temperature by genetic algorithm steam consumption of papermaking process is further reduced.

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