The influence of Yankee hood on paper drying

The Yankee hood is a kind of drying equipment commonly used in modern high-speed paper machine, especially for high-speed tissue paper machine, special paper machine and toilet paper machine. The so-called high-speed paper machine is a large workshop with high automation, high output, fast speed and low manual participation, which can be produced only by a few people.

Using the principle of contact drying and convection drying, Yankee hood uses high-temperature and high-speed hot air to blow to the paper web to form convection heat transfer. When the hot air blows to the paper web, the air film on the interface is damaged or the thickness is reduced, so as to strengthen heat transfer and evaporation, improve the paper drying rate and output, and reduce energy consumption. When the wet web is introduced into the pressing area, the drying operation occurs at the moment when the web contacts the cylinder block, and then the web is pasted on the cylinder block surface. The moisture transfers the heat and quality in a very complex form. When the moisture in the web becomes water vapor, it flows from the closed space of the wet web to its surface, migrates out in the form of liquid, fills all the voids, and then spreads out to the outside In the environment.

The Yankee hood perfectly combines convective drying and contact drying, improves the drying rate of Yankee dryer, greatly improves the output, reduces the steam consumption, saves a lot of energy for the enterprise, and improves the economic benefits of the enterprise.

The drying capacity of high-speed hot air Yankee hood is 4-10 times higher than that of ordinary hood. Its special drying mode is very friendly to the softness and loose thickness of paper, and its economic benefit is high, so it is widely used by many thin paper mills.

High speed hot air Yankee hood

The high-speed hot air Yankee hood has several factors for the drying rate of paper web during operation:

① Paper is related to the heat transfer area of the hood

The hot air nozzle of high temperature Yankee hood has good geometry, which ensures that the paper web is horizontally dry and even, and the moisture distribution is consistent;

② The speed of high temperature air

If the temperature of the air ejected from the hood is increased, the heat transfer will be increased by 30%;

③ Advantages and disadvantages of hood structure design

The structure design of the hood is reasonable, and the raw materials for making the hood have good heat resistance;

④ Strength of raw materials used to make the hood

The raw materials for making the hood are easy to be cut, welded and formed, and have strong corrosion resistance; the surface of the hood must have a thermal insulation layer made of thermal insulation materials, to prevent the high temperature air of the hood from leaking out, to avoid the damage of various devices around or fire caused by the leakage of high temperature air.