Paper Machine Air Cushion Headbox

Air Cushion Headbox

Air cushion Headbox: square cone tube pulp distribution, step diffusion, oblique pulp feeding, double homogenizing rollers, front overflow, adjustable upper lip plate for front, back, up and down, worm gear and worm gear full width adjustment, and micro adjuster local adjustment. The arc-shaped structure box has a quick opening door structure, with a transparent hole and a water spray device on the top.

Headbox body

The arc-shaped enclosed attenuation chamber has overflow holes on both sides (overflow flow rate of 5%), which can be installed as single-sided overflow or double overflow according to needs. At the same time, oblique pulp injection is adopted to reduce the phenomenon of pulp retention in the headbox. There are interfaces on the headbox for installing automatic control liquid level and pressure transmitters. There are quick openings at both ends of the spraying port for cleaning, and a flange port at the top for connecting the Roots blower. There is a stainless steel ceramic spray pipe on the top of the box, and a manhole with a diameter of 400mm is opened on the side wall panel for conveniently cleaning.

Inlet cone pipe

Composed of large and small ends and square cone tubes, both ends are equipped with connecting flanges, made of stainless steel plates, and the inner wall is finely polished. The purpose of the pulp main pipe is to ensure that the pulp flows evenly and uniformly into the entire headbox. At the small end of the square cone tube, there is a return pipe and a return flow control valve to balance the pressure inside the square cone tube and achieve equal pressure inside the square cone main pipe. There should be a transition straight pipe of 6D or more outside the inlet end to stabilize the pulp during the flow process, and a transition straight pipe at the reflux end to stabilize the pulp during the flow process. The pulp distribution main pipe is equipped with three quick cleaning windows and a balance tube sight glass. The opening size of the reflux valve should be adjusted according to the direction of the pulp flow inside the sight glass tube. The designed reflux rate is 10%, and the refluxed pulp is sent to the front of the slurry pump. The reflux control relies on manual valve adjustment. The inner wall smoothness is 0.4u. A cleaning hole is opened in the slurry inlet pipe for easy cleaning.

Pulp distribution components

The three-stage stepped diffuser adopts precision calculation and processing, and is made of integral die cast organic glass material.  

Perforator (distribution roll)

Manufacturing of stainless steel pipes for roller bodies. The transmission side is equipped with a gearbox and a Y-series motor, with a motor speed of 1450 revolutions per minute and a power of 1.1KW. The homogenization roller is equipped with a continuously variable speed adjustment gearbox, and the adjustment handwheel is used to change the speed of the homogenization roller to achieve the best homogenization effect. The opening rate and aperture of the homogenization roller are designed according to the pulp and machine speed. The opening rate of the throat roller is between 32-35%, and the opening rate of the weir plate roller is between 48-52%.

Upper lip adjustment device

The overall adjustment of the upper lip plate adjustment device adopts a full range adjustment form, and the local fine-tuning adopts a manual point adjustment method. The entire upper lip plate is designed as an anti deformation frame. The upper lip plate can be adjusted up and down within a range of 0-80mm. The dial gauge adjuster can finely adjust the lip opening locally, so that the paper width can be adjusted within the allowable range. By adjusting the return flow rate of the cone tube and the vertical small lip plate to adjust the horizontal quantitative difference, if the adjustment is correct and the process adjustment is appropriate, the horizontal quantitative difference can be controlled within ± 1.5%.

The lower lip plate is designed as an integral frame structure to prevent deformation, and the lower lip plate is fixed.

Spray pipe: made of stainless steel, and the nozzle is a special nozzle.

Walkway: In order to facilitate the adjustment of the upper lip plate, a walkway is provided in front of the flow box. The walking board, escalator, and railing are all made of stainless steel material.