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Basic grinding research and raising unit capacity. Final report; Hionnan perustutkimus ja yksikkoekapasitettin nosto; Loppuraportti

Technical Report:

Abstract

The project looked at ways of improving the energy economy of pressure grinding and the quality of the PGW produced. The biggest improvements, are super-pressure grinding (PGW-S) and the use of low temperatures in pressure grinding. The PGW-S groundwood mill built at Voikkaa in 1990 has produced the expected improvement in pulp strength and paper printing characteristics. Yet specific electrical energy consumption is just as low as in open grinding. Taking all mechanical pulps into account, pressure grinding gave the highest energy efficiency, i.e. pulp strength per unit energy consumption. Calculated in terms of tensile strength, the energy efficiency of PGW-S suitable for demanding printing papers is almost 50 % superior to that of TMP. Lowering the temperature used in pressure grinding produces almost the same pulp strength as in pressure grinding at the normal temperature. However, the pulp had a much smaller coarse fibre fraction, which improves the paper`s surface structure and reduces the tendency towards surface roughening when the paper is coated or printed. The pulp produced by new low-temperature pressure grinding process also has excellent brightness. Pilot-scale trials showed that halving the peripheral speed of the grindstone cuts specific energy consumption by about 15 % and improves  More>>
Authors:
Karojaervi, R [1] 
  1. Valmet Tampella Oy, Tampere (Finland)
Publication Date:
Oct 01, 1993
Product Type:
Technical Report
Report Number:
KCL-KUITU-26
Reference Number:
SCA: 320303; PA: FI-93:003303; EDB-94:013018; NTS-94:007760; ERA-19:004308; SN: 93001063844
Resource Relation:
Other Information: DN: FIBRE Research Programme; PBD: 1993
Subject:
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; PAPER INDUSTRY; GRINDING; ENERGY CONSERVATION; TEMPERATURE DEPENDENCE; WOOD; ENERGY CONSUMPTION; GRINDING MACHINES; FIBERS; PRESSURIZATION; OPTICAL PROPERTIES; MECHANICAL PROPERTIES; CAPACITY; SLURRIES; 320303; EQUIPMENT AND PROCESSES
OSTI ID:
10111533
Research Organizations:
Finnish Pulp and Paper Research Inst., Espoo (Finland)
Country of Origin:
Finland
Language:
Finnish
Other Identifying Numbers:
Other: ON: DE94702101; TRN: FI9303303
Availability:
OSTI; NTIS
Submitting Site:
FI
Size:
27 p.
Announcement Date:
Jun 30, 2005

Technical Report:

Citation Formats

Karojaervi, R. Basic grinding research and raising unit capacity. Final report; Hionnan perustutkimus ja yksikkoekapasitettin nosto; Loppuraportti. Finland: N. p., 1993. Web.
Karojaervi, R. Basic grinding research and raising unit capacity. Final report; Hionnan perustutkimus ja yksikkoekapasitettin nosto; Loppuraportti. Finland.
Karojaervi, R. 1993. "Basic grinding research and raising unit capacity. Final report; Hionnan perustutkimus ja yksikkoekapasitettin nosto; Loppuraportti." Finland.
@misc{etde_10111533,
title = {Basic grinding research and raising unit capacity. Final report; Hionnan perustutkimus ja yksikkoekapasitettin nosto; Loppuraportti}
author = {Karojaervi, R}
abstractNote = {The project looked at ways of improving the energy economy of pressure grinding and the quality of the PGW produced. The biggest improvements, are super-pressure grinding (PGW-S) and the use of low temperatures in pressure grinding. The PGW-S groundwood mill built at Voikkaa in 1990 has produced the expected improvement in pulp strength and paper printing characteristics. Yet specific electrical energy consumption is just as low as in open grinding. Taking all mechanical pulps into account, pressure grinding gave the highest energy efficiency, i.e. pulp strength per unit energy consumption. Calculated in terms of tensile strength, the energy efficiency of PGW-S suitable for demanding printing papers is almost 50 % superior to that of TMP. Lowering the temperature used in pressure grinding produces almost the same pulp strength as in pressure grinding at the normal temperature. However, the pulp had a much smaller coarse fibre fraction, which improves the paper`s surface structure and reduces the tendency towards surface roughening when the paper is coated or printed. The pulp produced by new low-temperature pressure grinding process also has excellent brightness. Pilot-scale trials showed that halving the peripheral speed of the grindstone cuts specific energy consumption by about 15 % and improves the strength of the pulp by some 10 %. The next step is to move up u production scale, when the energy efficiency of pressure grinding can be improved by a further 20-30 %. Ways were also devised to raise the unit capacity of pressure grinders by around 20 %}
place = {Finland}
year = {1993}
month = {Oct}
}