|2014 January JAPAN TAPPI JOURNAL|
|Vol.68, No.1 Abstracts
The Present Condition of the “AOKI CLEANER”in the Paper Manufacture Industry
― Blade Type Canvas Cleaner ―
Aoki Machinery Co.,Ltd.
In recent years the operation troubles of paper machine and its quality problems occur more frequently due to foreign materials including sticky pitch coming from increasing recycled paper usage. The sticky materials and pitch on canvas causes paper break at dryer, faulty spot, frequent splicing at winder, which decrease productivity.
Screening, pitch control chemical, high pressure water has been used to improve these situations, but these measures cannot solve the problems completely.
We, AOKI Machinery, has been developed “AOKI CLEANER”, an epoch-making blade type canvas cleaner. Let us introduce its mechanism and some operation facts.
Simplified and Energy Saving of Screen System
― MaxFlow Screen Series ―
Technical & Engineering Department, AIKAWA IRON WORKS CO.,LTD.
The screening which works as the impurities removal system from paperstock is the most important and common stage for today's all paper manufacturing process. And, everyone who works in paper industry desires strongly its performance improvement and reduction of power.
MaxFlow Screen and MaxSaver which were awarded a Japan TAPPI Sasaki prize 2013 are the AIKAWA's newest outward flow, vertical and pressurized type screens. They are armed with state-of-the-art casing structure, rotor and screen cylinder, and achieve both of impurities removal performance and power consumption reduction, at the highest level.
We appreciate for strong supports from MaxFlow Screen and MaxSaver users, and appreciate for having been able to get a very good chance to introduce them formally in this paper to paper manufacturing industry again.
Manufacturing and Application of Nanocellulose
Go Banzashi, Yasutomo Noishiki, Yuichi Noguchi, Takayuki Shimaoka, Katsuhito Suzuki
and Yoshiyuki Asayama
Advanced Technology Laboratories, Oji Holdings Co., Ltd.
Cellulose nano fiber (CNF) is nano size cellulose fiber with high aspect ratio, which is produced by fibrillation of pulp. In order to facilitate fibrillation of pulp efficiently, we investigated new chemical pretreatments (e.g. Oxidation, Esterification). Using these techniques, we can control its size (short or long, coarse or fine) and surface charge (anionic, cationic or neutral). Using this CNF, we have been successful in manufacturing continuous CNF sheets.
Economics of Ethanol Production in a Repurposed Kraft Pulp Mill
NPI Research Lab., Nippon Paper Industries Co., Ltd.
Richard Phillips, Hasan Jameel and Hou-min Chang
North Carolina State University
Commercial production of cellulosic ethanol is difficult. One of the reasons is high capital expenditure relative to ethanol product value. A repurpose scenario has been proposed from North Carolina State University (NCSU). In this scenario, available capacity of a kraft pulp process is used as a pretreatment facility of the ethanol production process. In consideration of repurpose scenario, some potential advantages are identified: reduced capital expenditure, experienced employees skilled in pulp operations, etc.
For the repurpose scenario, pretreatment of wood chips with green liquor followed by oxygen delignification and refining has been developed. In the optimized condition the sugar yield after enzymatic hydrolysis (on chip) was about 56%. In addition, saccharification technology with multi-stage clarifiers has been examined to make enzymatic hydrolysis more efficient.
Framework for financial analysis is developed with WinGEMS※, a process simulator for pulp and paper mills. NREL reports are public useful databases of fermentation and capital investment for the analysis.
With those method and technology, economics of cellulosic ethanol production in the repurpose scenario was analyzed. The total cost was 125.5JPY/L. From a sensitivity analysis， variable costs of chips and enzyme was found to have a significant impact on the total cost. Capital expenditure of repurpose scenario was one fourth compared to that of greenfield scenario, which means the repurpose scenario is an attractive solution.
Thermal Spray Coating onto the Shell of Yankee Dryer and the Operating Experience of PMT4 Tissue Machine
Kasugai Mill, Oji Paper Co., Ltd.
PMT4 tissue machine in Kasugai mill has been in operation since 1993, and it is producing tissue paper. The shell of Yankee Dryer (YD) had worn thin, and the surface of YD had become coarse. We solved these problems by coating the shell with the method of thermal spraying. This paper reports the experience of thermal spray coating onto the shell of YD and the operating experience.
Practical Use of the Camera Type On-Line Formation Sensor for the Improvement of Sheet Formation
NPi Research Laboratory, Nippon Paper Industries Co., Ltd.
Well-controlled sheet formation is necessary to ensure optimal physical characteristics leading to product quality and waste reduction. To evaluate and control the sheet formation, a good on-line formation sensor is required that is able to give us enough information such as flock size distribution, trend and so on.
We installed the camera type on-line formation sensor, which is able to detect the transmission images of the running web and evaluate the sheet formation (formation index and flock shape) intermittently, on the newsprint paper machine. We analyzed the relationship between sheet formation measured by the sensor and the operating condition. We succeeded in improving the sheet formation with the optimization of the dewatering condition on the former of the paper machine and the furnish arrangement.
Numerical Analysis of Fountain Coating Applicator
Yousuke Ozeki and Masaru Yasuhara
MPM CAE Center Co.,Ltd.
We verified the behavior of coating liquid onto the running web the fountain applicator by the numerical analysis.
As a result, the condition of the dirt lip fountain was simulated by the Reynolds number.
Furthermore, the proper range of both coating speed and viscosity is also clarified by using the Reynolds number.
We found that, the numerical analysis is effective to find out optimum design of the phenomenon.
Reinforcement Constructions of Niigata Sheet Finishing Machines
Hokuetsu Kamiseisen Co., Ltd.
At Japan Tappi seminar, in May 2013, we made a presentation the title is “Operating experience of New Sheet Finishing Machines”. We reported the outlines of new sheet wrapping machines and new skid wrapping machines for the export sheet paper. At that time, new Pasaban-made cutter machines we adopted had just started up. In this paper, we report the characterization and running situations of new cutter machines. We run a lot of cutter machines because the ratio of sheet paper we produce is relatively high volume than web. On deciding the adoption of new cutter machines, the overseas results are also appealing points. There have been many operation results of Pasaban-made cutter machines all over the world. In Japan, there have been results for paperboard, but there is no experience for paper. The new cutter machines we adopted have been running with high efficiency rather than existing ones we have.
Renewal of Wastewater Treatment Facility and its Operating Experience
Facilities Department Yashio Mill Rengo Co.,Ltd.
Rengo Co., Ltd. Yashio Mill has installed a new wastewater treatment facility for the use of recycling water due to the decreased performance and aging structure of the existing facility. Under the spatial constraint, a highly-efficient, energy-saving, compact system had to be designed in the renewal project. Eventually, Sumi-Sludge® System, a high-rate coagulation system, was selected after a comparative investigation of those including suspended carrier process, oxygen aeration process, multi-stage biological process, and membrane bioreactor. The new system is equipped with high-rate coagulation precipitators, Sumi-Thickner®, which concentrate the activated sludge to a high extent. With the aeration tanks also keeping the MLSS in high consistency, the system is designed to treat the wastewater efficiently with the BOD volume load of 2 to 3 kg-BOD/m3/day.
As the characteristics of the system, it keeps good conditions of the microbiological ecosystem and sedimentation property which enable a highly efficient treatment while the property and flow rate of the wastewater are kept stable. On the other hand, owing to the space-saving design, the surface level of the activated sludge tends to fluctuate widely once the sedimentation property worsens. Besides, high consumption of chemicals such as coagulant, and high sensitivity of the performance to the fluctuation of the wastewater property and flow rate are also observed.
Here we report the implemented measures against the above, including the control of MLSS, adjustment of effluent flow rate, reselection of chemicals, and additional installation and modification of auxiliary machines. These subjects need to be resolved continuously for the future by accumulating operational experiences and further improvements.
Plant Design and Operational Performance of RPF and Wood-Chip Co-Firing Boiler
― Concern for Environment and Reduction of Fossil-Fuel Consumption ―
Mishima Mill, Tokushutokai Paper Co.,Ltd.
In order to reduce the consumption of fossil-fuel, RPF and wood-chip co-firing boiler was constructed at Mishima Mill, and it started the operation in 2012 after the shut-down of existing heavy oil fired boiler. Installation of the new boiler resulted in the reduction of both energy consumption and carbon-dioxide emission from energy usage.
Since the mill is located in residential area, the boiler was designed in a way that takes the surrounding environment into consideration. Fuel hopper and ash banker are placed indoor to prevent the spreading of dust. Dust collectors are installed in various places such as fuel hopper, fuel conveyor, ash banker, and sand banker.