A hydraulic headbox is designed to deliver a uniform, low consistency stock stream to the Fourdrinier wire. It is important to monitor the geometry of the stock jet. Flow modeling of a hydraulic headbox with a tapered manifold, a large array of diffuser cross-machine direction are dependent on the headbox design and. Abstract—An experimental study of the flow in a modeled hydraulic headbox of papermaking machines was performed. The turbulent boundary layer generated .
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The paper machine headbox is an equipment headbkx supply very low consistency stock into the forming section uniformly. The formation and uniformity of the final paper product depends on the dispersion of the fiber and fillers. The furnish delivery system varies on the construction of the headbox. It has a significant effect on paper qualities. All the headbox are not suitable for all grade of paper and machine speed. A well constructed Headbox can provide high quality board and paper and higher productivity.
So the design should be properly. Now a days Hydraulic type headboxes are commonly used in the pulp and neadbox industry.
The headbox is also known as flowbox. Normally the headbox is categorized into three types such as open type, air pad type and hydraulic type.
In hydraulic and Air pad headboxthe discharge velocity from the slice depends directly on the feeding pump.
For this reason they commonly known as pressurized headbox. The hydraulic headbox has no hydrzulic pad, it is fully enclosed. In case of air pad headbox a pond level is maintained. Above the level it contains pressurized air.
The stock level is known as head, which is controlled by air pressure. The head determines the slice jet speed. It contains two or three Rectifier roll.
Paper machine headbox | pulp paper mill
Moreover multi-layer hydraulic headbox is available which is designed for making tissue paper and lightweight containerboard. Each layer has different furnish compositions and delivery system.
The headbox jet velocity is very important factor for manufacturing high quality paper. You should accurately maintain the jet-to-wire velocity ratio; it should be in the range of 0.
Hydraulic headbox with dilution before diffuser
If the headbox does not perform these functions correctly then the quality of the paper will be greatly hampered. You will get many benefits from the well constructed headbox. It can improve formation and paper quality, reduce number of breaks and downtime, fewer pinholes, dirt spots, improve runnability, increase machine speed, stabilized paper caliperimprove water removal, and reduce chemical cost. All these properties are achievable, if the CD basis weight profile, main fiber direction, uniform formation, flatness, etc.
This roll are used in paper machine headbox to control both the even out flow irregularities and to create turbulence to keep the fiber dispersed up to the slice opening.
It is also known as hollow perforated roll or holey roll. Normally the hole diameter is about 2 to 4 cm. The paper machine headbox slice is a full width nozzle with a completely adjustable opening to give the desired rate of flow. The slice contains two lips; top lip and bottom lip. Among them the top lip is adjustable; you can up or down them with hand operating or motor driven.
On the other hand the bottom lip is fixed. The distance between the two lips are called slice opening. This slice opening controls the stock jet velocity which is vital for paper formation. Jahir you can contact: Your email address will not be published. Notify me of follow-up comments by email.
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Paper machine headbox Posted on December 16, by admin. This entry was posted in paper machinery and tagged headbox jet velocity calculationheadbox paper hysraulic, hydraulic headboxpaper machine headbox designpaper machine headbox typesslice lip headbox. March 26, at 2: April 9, at 9: May 24, at June 26, at I have 6 month experience at paper machine in paper mill can somebody guide me for a new job.
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