Slanting web pulp system
With the continuous improvement of the paper quality and the emergence of high speed and modern papermaking machines, the pulp system of paper machine is called flow feed system or short cycle system, which is a very important process in modern papermaking technology. Including the mixing, purification, screening, degassing, circulation, flow and other processes. There are multiple stages of sand removal, multi-stage screening, vacuum degassing and other processes combination.
A good sizing system must meet the following requirements:
(1) ensure stable operation and control of the system.
(2) constant grouting amount reduces the pulsing pressure pulse.
(3) all kinds of fibers, fillers, chemicals and white water are mixed uniformly to avoid slurry clumping, deposition and flocculation.
(4) the slurry has good degassing effect and the concentration should be stable.
(5) the system is easy to clean. Simple process and investment economy.
Now the major foreign papermaking equipment supply companies like metso, voith andritz has produced sophisticated equipment, such as: low pulse degassing apparatus sizing pumps, efficient desander, low pulse pressure screen, vacuum tanks, etc., these equipment can meet the quality requirements of various kinds of paper, this article only equipment sizing system and piping arrangement, summary and other non-standard equipment design, for many domestic papermaking enterprises to the design of the system or as a reference.
Effect of sizing system on quality of paper pages
The longitudinal quantitative variation of the page is caused by the pulsing system producing pulses which are inherent in the equipment and cannot be completely eliminated. It is reported that if the design of the sizing system is not reasonable, the longitudinal quantitative difference of the paper page can be up to 8-10%. On the other hand, if the pulp in the sizing system contains air bubbles, a needle hole or small hole will be formed on the paper page, and the stain of anionic adhesive will have a great impact on the quality of the paper page (especially on the whole page).