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
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Karojaervi, R
[1]
- Valmet Tampella Oy, Tampere (Finland)
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}
}
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}
}