Features of modern new headbox paper machine

Throughout the modern new high-speed headbox paper machine, it basically has the following main features:

(1) Adopt high-efficiency hydraulic slurry rectifying components. Through the design of different structures and sizes of the hydraulic slurry rectifying elements, different slurry flow conditions can be adjusted and controlled to meet the requirements of different process conditions.

(2) Pay attention to the role of the slurry chamber. The slurry stabilization chamber can eliminate and attenuate energy fluctuations and stabilize the slurry flow. For a full-flow air-cushion combined headbox, the slurry stabilization chamber is a place where air cushions are generated and air bubbles are eliminated.

(3) The narrow and long flow channel is used to produce controllable fine turbulence. The narrow and long flow channel can be used in the outlet section of the headbox to control the turbulence of the outlet slurry flow to generate fine-scale turbulence, which is more prominent in the vane headbox.

(4) The trend is toward a rectification of pulp distribution. Most of the new headbox paper machines are two-stage pulp rectification, but there are also attempts to develop into a primary pulp-distribution rectification. If the slurry flow can be well distributed, this may become a development trend in the future.

(5) Equipped with external pulse attenuation device. One weakness of the full-flow headbox paper machine is that it is very sensitive to pressure pulsation. Therefore, in addition to improving the headbox itself, an effective method is to install an automatic pulse attenuator outside the machine.

In the future, the design of the headbox paper machine will continue to develop towards the following trends:

(1) Through adjusting the pulp density to control the full width transverse quantitative. The eye-catching new technology in the 1990s was the full-frame lateral quantitative controller. Compared with the traditional headbox lip bending adjustment method, it can not only effectively adjust the uniformity of the full width transverse quantitative, but also maintain the uniformity of the full width fiber orientation, which is a better quantitative control method.

(2) Towards the direction of adapting to various shapers. In the transformation of existing paper machines, it has become a trend to retain the original organisms and change the wire. Since different shapers have different requirements for the headbox, the headbox must be designed to adapt to various shapers.

(3) The headbox paper machine is developing towards more precise adjustment and better control.