4200mm Stainless Steel Close Type Air Cushion Headbox For Fourdrinier Paper Machine

4200mm Stainless Steel Close Type/Air Cushion Headbox Used For The Fourdrinier Paper Machine

1. Head box

Head box type: air cushion type head box

Over flow: 2~5%

Tapered flow header reflux: 10~15%

Head box lip width: 4550mm

Top lip vertical adjustment range: 5~75mm

Top lip horizental adjustment range: 0-25mm

Bottom lip is stationary type

Inflow pulp consistency range: 0.4~0.8%

Head box lateral gram difference: < ±1.5%

Air cushion type head box adopts stainless steel tapered flow header, organic glass 3 steps pulp diffusion feeder, stain less steel plate welded body, stain less steel evener roll 2pcs, stainless steel made lips, top lip can make full or partial adjustment, trimmer spacing 120mm, with controlling system which can be connected with DCS system to achieve programming logical control, head box body is with organic glass inspection hole to observe pulp level

1.1 Tapered flow header

Tapered header design, with reflux opening, stainless steel wielded body, polished inner wall, can be opened for easy maintenance and cleaning

1.2 Orifice diffusion device

Head box is with orifice diffusion device, organic glass made to ensure even pulp feeding

1.3 Evener roll device

Two sets of pulp evener roll, stainless steel made with double spiral lined holes, both side wall of evener roll and hole openings are polished, worm box mechanical speed less adjusting between 9-50rpm according to process requirement

1.4 Top lip adjusting device

Including general adjusting device and fine tune device, by rotating the hand wheel, top lip can move upward or downward as a whole to achieve the opening per production requires, fine tune can adjust partial lip opening to improve paper lateral gram difference, combined lip system with vertical small lips lined horizontally with great elasticity to further improve the distribution of pulp, small vertical lips are equipped with micro adjusting device with dial indicator shows a value of 0.01mm to achieve precision adjusting

1.5 Head box body

Stainless steel plate wielded body with fine polish treatment for the parts has direct contact with pulp, clean and smooth, which ensures no hanging fiber on the surface, the foundation of the head box adopt cast iron structure

1.6 Compressed air of the head box is supplied directly by the air system, equipment including low pulse roots blower, silencer for inlets and outlets, motors, valves and pipelines. Blower adopts frequency speed control, controlled directly by controlling system

1.7 With overflow opening to ensure constant pulp level

1.8 Walking platform

To facilitate the adjusting of top lips, a lateral platform is installed on the top front part of the head box, walking plates, railings and hand rails are wielded by stainless steel plate

1.9 Controlling system

The controlling system of the head box includes the control of pulp level and the pressure in the head box tank. The control of pulp level is obtained by liquid level transmitter sending signal to the computer. The total pressure is the sum of pulp level pressure and air pressure. The pressure sensor will read a signal and send to the decoupling software, after processing, an execution signal will be send to pulp feeding pump and blower motor frequency converter to achieve automatic control of pulp feeding amount and slurry pressure. The controlling precision of pulp level and total pressure are both ± 0.5%

Controlling system description:

Low pulse air supplying system

The main function of this system is continuously supply compressed air into the head box. It is consisted of low pulse roots blower, silencers, vibration-proof platform and pipelines etc. To obtain a stale paper weight, the head box adopted imported low pulse blower and high efficiency silencer, combined with elastic structure vibration proof platform, it can absorb vibration and noise generated by the blower to the max extent and ensures a stable and even compressed air supply

Computer control system

Automatic control of slurry pressure and amount, it is consisted as below:

Pressure measurement system (pressure sensor, pneumatic pressure control valve)

Liquid measurement system (liquid level sensor, hydraulic control electrical valve)

Decoupling (controller, industrial control computer, display screen)

In addition to manual and automatic control function, the system also has working condition recording and display functions