What are the two types of blow boxes with different functions?

In the modern paper machine, due to the use of closed hood, it is necessary to balance the air exhaust of hood with low temperature and high temperature on the modern paper machine. In order to make the paper web run smoothly at high speed and improve the transverse moisture distribution of the paper web, according to the different paper grade and working speed, there are blow boxes with different functions.

1. Traditional pocket area blow box (ventilator)

The air dryer is a drying part composed of two rows of drying cylinders and two fabrics. It is a relatively closed area composed of thousands of fabrics, paper sheets and lower drying cylinders. This area is commonly known as "pocketarea". The air flow in the pocket area is very slow to exchange with the outside, the drying of the paper will be greatly affected, the moisture content of the paper in the cross direction is also very uneven, the moisture content at the edge of the paper in the CD is less, and the moisture content in the middle is more. In order to solve this problem, the common practice in the world is to set up pocket area blow box at the upper dry fabric. The method of blowing box nozzle to send high-speed hot air is to set pocket area blowing box at the upper dry fabric. The high-speed hot air is sent into the pocket area by the blowing box nozzle, and the saturated humid air in the pocket area is replaced by the dry hot air, so as to improve the drying efficiency of the drying cadres and the moisture distribution of the paper in the CD. This kind of pocket blowing box is widely used in new paper machine, and it can play a more important role in old paper machine. According to different kinds of paper, the nozzle of the pocket area ventilator has different forms to meet different requirements. The pocket area ventilator is equipped with a zone air volume regulating device in the transverse direction of the paper machine, which can conveniently adjust the air volume of each zone at the driving side of the paper machine, so as to achieve the uniform distribution of the transverse air volume of the paper machine.

2. Stable paper ventilator

For the air dryer, the drying section is mainly arranged with a single row of drying cylinders and a single dry fabric. Through a lot of research, the world's largest paper machine manufacturers have designed a stable paper blowing box. In the area enclosed by the lower cylinder (or vacuum roller) and the dry fabric, a stable paper blowing box is installed to blow the air out at high speed, and at the same time, the air is blown out at the end of the stable paper blowing box to form an air seal. Due to the induction of the air flow, a negative pressure area is formed between the stable paper blowing box and the dry fabric. This kind of negative pressure tightly adsorbs the web on the dry web, so as to avoid the web shaking, wrinkling and paper breaking, and solve the problem of high-speed paper machine in operation. We have done a lot of research on all kinds of blow boxes, and now we have mastered the technology in this field.

With the above two kinds of blow boxes, the manufacturers of blow boxes can solve the problems of drying, operation stability and transverse moisture distribution.