JAPAN TAPPI JOURNALVol. 58, No.5

May 2004 Abstracts


Results of the FY 2003 Follow-up to JPA's Voluntary Action Plan and Report of Energy Situation in Pulp and Paper Industry in Japan
Kunihiko Aida
Japan Paper Association

　The Japan Paper Association (JPA) has been actively working to save energy since 1997 when it established its "Voluntary Action Plan on Environmental Issues". JPA declared its policy of restraining CO2 emissions as one of the actions: By 2010, reduce the unit of fossil energy for paper products by 10% from that of 1990 level.
　Since 1998, JPA has been following through on the actual results of the unit of energy in the year, and has been publishing its results compared with that in 1990 every year. The following are the results for 2002 and the report of energy situation in pulp and paper industry in Japan:
　Unit of fossil energy in 2002 was smoothly reduced by 6.6% from the level in 1990. However, the reduction in a unit of CO2 emissions remained 2.3% because cost competitive coals have been largely used.
　Paper and paperboard production increased by 9.8% in fiscal 2002 compared to that of 1990 level, whereas, increase in CO2 emissions remained at 7.3% from the 1990 level. A breakdown of the 2.5% reduction from 9.8% to 7.3% shows that the pulp and paper industry decreased by 2.2% and electric companies contribute to reducing the remaining 0.3% (from effective generating and transmission electricity).
　According to 22 companies that replied to our questionnaires, a total of 14.8 billion yen was invested in energy saving measures for fiscal 2002 and the crude oil equivalent of energy saved reached 290 thousand kiloliters per year. As far as the estimation from 20 companies, 44.5 billion yen will be invested and 254 thousand kiloliters per year will be saved from 2002 onwards.


Energy-saving in Stock Preparation-Energy-saving by a Renewal to the Low No-load Horsepower Small Refiner-
Koji Nomura
Production Dept. Fuji Mill Nippon Paper Industries Co., Ltd.

　Increasing the social demands to saving natural resources and the environmental protection, the production of the recycled paper has grown every year. The new plant of recycled pulp operated at Fuji Mill in 2000, and it has corresponded to the demand of recycled paper. While the production of products with a high use ratio of recycled pulp are increasing, the production of products with virgin pulp tend to decrease at 7,8M/C which manufacture colored paper, printing paper and base paper of coated paper. Therefore the quantity of bleached softwood, hardwood kraft pulp used for the paper machines is decreasing. The capacity of the refiner and the pump for bleached softwood kraft pulp in stock preparation becomes excessive for the manufacturing condition with a little amount of virgin pulp use. And it is in a situation that can't be efficient power use. According to the situation of the pulp flowing quantity and freeness target, we make a study of using the small type of refiner for saving the energy.


Steam Saving in Paper Making Process-Steam Saving by Raising The Temperature of Pulp Slurry Using Hot Water and Recycling White Water from Paper Making Process-
Susumu Chiba
Hachinohe Mill, Mitsubishi Paper Mills Ltd.

　We have taken measures to reduce the energy consumption as one of the environmental improvement plan based on ISO 14001 standard in the Hachinohe mill of the Mitsubishi Paper Mills, Ltd. Company since 2001. And the target of the plan is to reduce the ratio of steam and electricity consumption to the paper production in the mill at the rate of 1 % every year.
　Therefore we studied the actual conditions of processes in the mill and made a plan to save fresh water from the view point that cutting the heat loss by saving the warm waste water sewage could lead to the saving of steam consumption . Based on the plan, some measures have been carried out since 2002.
　In this paper we describe the way to make the best use of hot water from a surface condenser in a black liquor evaporation plant and the way to reduce the size of a sand filter plant used for white water recovery from paper making process.


Energy Conservation of Screen
Tomomitsu Nihei
Kanto Mill (Ichikawa), Hokuetsu Paper Mills Ltd.

　Kanto Mill(Ichikawa), Hokuetsu Paper Mills Ltd is the factory which produces recycled paper, such as white board paper, as a major product.
　Taking advantage of conditions of location, and it is working considering the used paper the cargo oh is collected from a metropolitan area as main materials.
　Although this used paper quality is becoming an aggravation tendency in recent years,the quality level of the paper called for is severe conversely.The equipment which is greatly related to this quality level is screen equipment before a materials tone part and a paper maker. I report the example of two affairs about an improvement of a quality side and change of power saving.


Efficiency Improvement of GAS IR System on #51 Paper Machine
Yasunori Arakawa and Yoshihiro Kudo
Nippon Daishowa Paperboard Yoshinaga Co., Ltd.

　Energy-saving is a priority matter in paper and board manufacturing process, which consumes a lot of energy. Nippon Daishowa Paperboard Yoshinaga Co. Ltd.
aiming "Full Recycling mill" is focusing on it anytime and anywhere in the mill.
　By replacement the burners of GAS IR system to the energy-saving type on #51 which produces on-machine coated board, we successfully achieved the saving of energy. After the burners replacement, the drying capacity increased by improving thermal transmission efficiency which can expect us the saving of gas consumption. However, it was not so easy to determine the optimum gas output under the actual machine operation. This paper shows how we obtained the actual energy saving.


Reduction of Turbine Bypass Blow off Steam by Lowering the Minimum Load of No. 4 Boiler
Junya Ota
Sobue Mill Oji Paperboard Co., Ltd.

　No. 4 boiler (CFB; Circulating Fluidized Bed type) at our plant started operations in 1995 after our mill's fuel conversion program by taking the place of No. 3 boiler (heavy oil fired boiler).
　The maximum steam generation of No. 4 boiler was 120t/h and it has been in operation with steam generation between 95 t/h to 120 t/h when all four paper machines were in operation. The operation of one large paper machine was reduced from 2002 and the operation of the machine stopped in January 2003 completely. The required steam generation now ranges between 75 t/h and 96 t/h.
　Since the low-load operation of No.4 boiler causes a blockage in the combustion-air blowing nozzle at the bottom, the minimum operation load has been kept at 75 t/h. However, after the suspension of the large paper machine operation, power consumption at our mill when other machines are stopped for service and maintenance purposes has gone down. At a boiler load level of 75 t/h, power generation exceeds power consumption to result in a back feed to the power supply utility company. As a result, turbine bypass operation (blow off steam through turbine bypass valve) has become necessary.
　In order to lower blow off steam by the turbine bypass operation, boiler operation needs to be further lowered and grid nozzle modification was seriously considered.
　Grid nozzle type was changed from "pig tail" to "arrow head" to prevent bed material from entering the nozzle hole, so that nozzle blockage would not happen in low-load operation.
　Thanks to the grid nozzle modification, the present minimum load is as low as 62 t/h and the rate of nozzle clogging by calculation stands at 23%, which means there is no problem. The boiler has been in operation without turbine bypass operation.
　The reduction in blow off steam amount to the air as a result of low-load operation for the boiler currently amounts to about 600 t/month.


Boilers Energy Conservations
Teruhiko Tamai
Iwakuni Mill, Nippon Paper Co., Ltd.

　Power plant at Nippon Paper Iwakuni mill has six boilers: one bark boiler, two oil boilers and three recovery boilers (two of them are standbys), and nine turbine-generators (three of them are standbys). All electricity required for the mill operation can be generated from the power plant. Iwakuni mill has been modifying the operation, promoting reuse of exhaust heats, replacing some old equipment with higher efficiency ones and constructing new high efficiency plants as well in order to increase energy efficiency at the power plant.Energy saving is one of the very important issues these days for mill operations, however at the same time effective solutions to achieve valid energy saving cannot be easily recognized. Therefore the mill now is challenging to reduce energy consumption with new activity, such as introducing responsibility share on each sections for the target.
　This describes the result of the construction of Magna Drive, which started operation in Oct. 2003 and the plan for heat recovery of an oil boiler with S-CON, which is scheduled in 2004, as considerable solutions of energy saving.


The Energy Saving of the Power Plant
Tadayuki Kubo
Nomachi Mill, Chuetsu Pulp and Paper Co., Ltd.

　While no one predicts the future of the Japanese economy, each company is striving for cost reduction in order to survive. On the other hand, pulp and paper companies are tackling to energy-saving as the most important theme from the viewpoint of cost reduction and global environmental problem. At Chuetsu-Nomachi Mill, we have been proceeding to energy-saving in each process, then both the amount of generating steam and using power have increased due to the operation of No.1 coater machine (April, 1998) and DIP facilities (October, 1999). After we tackled to energy-saving in order to lower the load of the mill, as a result, we were able to attain the heat recovery by passing the circulation water (about 70℃) of the Desox equipment of No.4 boiler through the pre-heater of 1st FDF and 2nd FDF, and also we were able to raise the temperature of the deionized water by change of the extraction of the raw water going into the deionized water equipment. The example of application is introduced, as follows.


Automation 1n the WET End ProcessTM
Hideomi Uchikawa
Voith Paper Automation Japan Ltd.

　The literal German translation for approach flow system is Constant Part. It suggest that all process variations in this area directly upstream from the headbox have to be reduced a minimum in order to produce high quality paper.
　Pressure, flow and consistency variations can be reduced or eliminated by applying state-of-art process technology. Much of this is well known, proven technology. However, recent developments with new measuring instruments now permit the control of chemical behavior of the stock suspension of in the approach flow system.
　By combining retention with these new online measured parameters, and ensure both high quality and consistency of the finished paper.
　Total retention, filler retention, charge or gas content should be controlled depending upon the furnish composition of the grades that are produced.
　It will be shown in this paper how this can be integrated into the overall control architecture of Quality Control Management of the paper machine.
　Various practical experiences outline the high potential of these new control strategies.


Deoxygenate Equipment for Boiler Water by Nitrogen Gas
Satoru Ura
Toyobo Engineering Co., Ltd., Environment Solution Division

　Our Deoxygenate equipment for boiler water spends less Nitrogen Gas than other equipment. It may be about 1/3 quantity of old equipment. Our Deoxygenate equipment use special technology to make fine bubble. It is very effective for Deoxygenate from boiler water by Nitrogen Gas.
　If you use chemicals for deoxygenate boiler water. Our Deoxygenate equipment for boiler water saves large money.
　Although this equipment is a condensation filter, with the existing technology which adds a condensation agent in the water for processing, it is equipment condensed only by there being nothing, making into the shape of complications or a pellet substances, such as water magnesium oxide processed specially, and passing processing water to it.
　This equipment is equipment which converts an established waste incinerator so that the dioxin regulating method may be suited.


Pulp Bale Breaker-Pre-shredding for Stabilized Operations and Reduce Costs-
Masaki Maeda
Industrial Machinery Department.NIPPON SHARYO, LTD.

　Bale Breaker : SSI's slow-speed, high-torque shredders offer important solutions to meet your product reclamation and pre-processing needs. Shredding bales prior to pulping enables the hydropulper to be meter-feed a steady stream of consistently sized material. This improves and accelerates the blending process, resulting in increased capacity and efficiency (through lowered hydropulper energy and maintenance cost).Users have also reported reduced chemical usage and costs (because of accelerated material breakdown) as well as an improved end product.


Automatic Pallet fork transport system-Automatic Pallet-Robot-
Susumu Inaba
Maruishi iron works Co., Ltd.

　Maruishi manufactures and sells Pallet Shrink- Packing Machine and Pallet Dust Remover and so on, which have been developed under a technical tie-up between ourselves and REKER in Germany since 1991.
　We would like you to introduce the following Pallet-Robot. Pallet Robot is the full automatic fork style of skid transport system. The characteristic is as follows.
. Fully automatic working operation.
. No deforming sheets during pick-up and transport.
. Pick-up of a single skid out of a complete set.
. Transport of skids in any direction, also free turning of robot.(available for any kind of sheeter)
. One pallet robot can handle several sheeters, capacities up to 80 skids/hour.
(depending on layout)
　We would produce results such as we delivered more than 5 Pallet-Robots to Europe and one Pallet Robot to Japan in 2001.


Study on the Effect of Testing Conditions on Compressive Strength and Bursting Strength of Board
Masataka Ito, Hideki Izumi＊＊ and Yoshio Yoshida
Material Analysis Center, R & D Div., Oji Paper Co., Ltd.

　JIS P 3902 "Linerboards" specifies the compressive strength by ring crush tester and the bursting strength by Mullen high pressure bursting tester. The both strength tests have comparatively large variance on the test results among the testers. In this report, we studied the effect of testing conditions on the both strengths of board.
　On the compressive strength test, the parallelism of the upper and lower platens, the position of test piece holder on the ring crush tester, the position of test piece seam in the test piece holder, the kinds of die cutters and the kinds of ring crush testers had effect on the results.
　On the bursting strength test, the pressure at 10mm bulge height of diaphragm and the kinds of bursting testers had effect on the results.

Keywords: testing conditions, compressive strength, bursting strength, board, ring crush tester,high pressure bursting tester