Operating procedures for starting and stopping the drying section of a paper machine

(1) Key points of start-up operation of the drying section of the paper machine:

1. Check whether there are any abnormal objects in each group of drying nets, whether there are sundries inside and outside the machine, and whether there is paper wrapped around the shaft head.

2. Check the scraper of each part of the drying section, whether the lifting device is flexible, and whether the scraper is tight and reliable.

3. Check whether each group of movable paper pick-up pulleys is flexible, whether the position and angle are appropriate, and whether the positioning adjustment system of each drying net deviation automatic adjuster is normal.

4. Check whether the tightness of each group of dry nets is appropriate, and whether the adjustment devices of each group of dry nets are correct and flexible, and adjust the position of the handwheel according to the tightness of the dry nets before and after.

5. Drop each group of dryer scrapers, check again whether there is anyone working in the machine, and send out a start-up signal. Start the dryer group by group and run at the crawling speed. (If there is a large cylinder group, the active group should be started first, and then the driven group should be started)

6. At the crawling speed, check whether the drying net is good or not and whether the tension is appropriate. The drying net of the new machine is tensioned at the crawling speed, and adjust the adjustment handwheel to make it tight at both ends, and carefully check the threading rope. The condition of wear and whether the joints are strong and firm.

7. Ventilate and preheat the drying cylinder. After confirming that each part is set, change the speed when the drying cylinder has a certain humidity.

8. After the drying cylinder is quickly transported by air, pay close attention to the operation of the drying net and put the mobile scraper into motion.

9. According to the length of the shutdown time, the preheating of the dryer shall not be less than the following time, 20-30 minutes of shutdown under 4 hours, 4-12 hours of shutdown, 40-60 minutes of shutdown for more than 12 hours, more than 60 minutes.

10. At the same time of ventilation and humidification, start the exhaust fan of the dry net part to make the air convection in the air hood.

11. After the drying cylinder humidity reaches the requirement, close the straight-through exhaust valve of the condensate water to carry out the paper splicing operation.

12. During the paper splicing process, when the drying cylinder and the guide felt roller are wrapped around the paper, they should be cleaned up in time, and should not be washed with water. In serious cases, the machine can be stopped for processing.

(2) The main points of normal production operation in the drying section of the paper machine:

1. Always check the machine dry net and the running condition of the threading rope to ensure normal production.

2. Always pay attention to the speed of each group of drying cylinders, and adjust the tension of the paper web to prevent the appearance of broken ends and folds.

3. Pay close attention to the running of the paper web, and cut it off in time when the end is broken to prevent the paper web from blocking the drying cylinder. According to the length of the end-breaking time, properly close the air inlet valve of the drying cylinder.

4. Enter the factory to check the load of each group of drying cylinders, and deal with any problems (current) in time.

(3) Key points of the shutdown operation of the drying section of the paper machine:

1. After receiving the shutdown notice, prepare the repair and threading rope tools.

2. After the paper web is interrupted, close the intake valve, and the dryer will be idle for 20-30 minutes before stopping.

3. The drying section is changed to crawling, and the condition of each group of drying nets and each threading rope is checked in detail. If there is any damage, stop the machine to repair and replace it.

4. Clean the paper foam on the scraper, the paper strips on the rack and the ground around the equipment to be hygienic, and then stop the drying cylinder.

5. Each exhaust fan in the air stop hood.

6. If the downtime is more than 4 hours, each blanket dryer should be loosened.