Nozzle is a seemingly small and inconspicuous spare part on a paper machine, but from the headbox, wire pressing section, drying section, and coiling section, the existence of nozzles is everywhere. The quality of the nozzles used directly determines the quality of the paper produced by the paper mill, the service life of various felts, and the consumption of water or chemicals. Improper use of the nozzles may even lead to unnecessary machine downtime or equipment. damage. Therefore, although the nozzle is small, it is indeed a spare part that any paper mill has to pay attention to.
The main role of nozzles in papermaking
(1) Defoaming nozzle: To remove foam in pulp, hollow cone nozzle, silicon carbide crucible and spiral nozzle are used.
(2) Water needle nozzles for paper cutting: needle-type nozzles, which are required to work under high pressure conditions and need to be inlaid with ceramics or high alloys.
(3) Cleaning the nozzles of the cage felt: usually needle-type nozzles and fan-type nozzles, self-cleaning nozzles.
(4) Coating nozzle: Silicon carbide nozzle, which is the surface coating of paper, is used on the coating machine to atomize the nozzle.
(5) Pulp-pulling nozzle: a narrow-angle nozzle is used.
(6) Washing of the paper web: With the increase of the speed and width of the paper machine, the polyester forming wire is used more widely, and higher requirements are placed on the cleaning quality of the polyester web. Using nozzles for paper web washing can prolong the life of polyester webs, textile paste webs, use nozzles to remove impurities in secondary fiber recovery, and use nozzles to prevent paper webs from being polluted in the white water closed circulation system.
(7) Cleaning the felt: using a good high-pressure spray is an effective measure to achieve efficient washing. Practice has proved that continuous spraying with a pressure of 1.0-1.5MPa during the operation of the paper machine can achieve the purpose of effective washing, and the The fluff on the surface of the blanket will not be damaged, and the moving range and speed of the high-pressure water spray pipe must also be reasonably adjusted, otherwise the spraying overlap or omission will occur, and streaks will appear, which will affect the quality of the product. Fan-shaped nozzles are generally used in washing, and the punching point of fan-shaped nozzles is best chosen beside the rotating guide roller, not on the tension roller, and directly flushes the running surface.
(8) Trimming water needle.
(9) Humidification in paper processing plants.
(10) Starch coating.
(11) De-foaming of the headbox.
(12) Cleaning of the vacuum suction roller on the Fourdrinier wire machine.