High-vacuum dewatering on a paper machine wire section - A literature review

In view of the energy used and the investments required for the vacuum dewatering equipment in a paper machine wet end, proper knowledge of the dewatering phenomena is most important. A literature review was carried out to gather information published on this subject. The review considers important process factors such as the dwell time of suction, suction level, different aspects of suction and temperature of the pulp. The influence of the furnish on high-vacuum dewatering is also reviewed. The review showed that high-vacuum dewatering has not been studied widely. Most of the experimental results were obtained using laboratory testers in which the dewatering action differed significantly from that on paper machine. Particularly, quantitative dewatering results are rare and models applicable to vacuum dewatering were not found.