Form | Features | Scope of application |
Open type | The pulp level in the box is used to control the speed of the online pulp (pulp speed), usually by adjusting the height of the weir in the box | Generally used in low and medium-speed paper machines |
Air cushion type | Use compressed air to adjust the air pressure above the pulp surface in the box to adjust the speed of the online pulp (that is, the pulp position does not change, and the air cushion pressure head is changed to obtain an appropriate pulp pressure head) | More widely used in paper machines with higher speeds
2. It is also used for some medium-speed paper machines |
Hydraulic full-flow type | The headbox is filled during the pulp flow process
Use the slurry pressure of the flushing pump, the slurry position of the high-level box or the air pressure of the air cushion stabilized head box to adjust the speed of the pulp on the Internet
3. It cannot absorb the pulsation of pulp, so it is necessary to set up a pulse attenuation device in the pulp feeding system (such as an air cushion stabilized headbox)
4. The full-flow headbox with special structure can be used as a multi-layer headbox | It is applied to the papermaking machine with sandwich screen or the new type fourdrinier paper machine or cylinder paper machine with higher speed |
Hydraulic Full flow air cushion combined type | Based on the general full-flow headbox, an air cushion stabilization chamber and overflow device are added to stabilize the pulp pressure in the box, eliminate pulsation and eliminate foam | It is applied to the papermaking machine with sandwich net and the fourdrinier paper machine with higher speed |
Hydraulic Multi-layer hydraulic | Along the Z direction (vertical direction) of the headbox, divide the propeller and rectifier unit of the headbox into several independent units (generally divided into 2-3 units), each unit has its own slurry feeding system | At present this kind of headbox is only used for sandwich paper machine |
