State Patent Product

Equipressure distributor

    This new distributor consists of stock inlet, damping element, mixing chamber, stock outlet and overflow outlet. It connects headbox with a series of flexible pipes. See Figure 1.

    Stock firstly feeds into the bottom of equipressure distributor through approach flow system. Then stock flows into a large mixing chamber through damping element and stock of mixing chamber is distributed into a series of flexible pipes, each of equal length and diameter and distributed in circumference of equipressure distributor uniformly. The other side of flexible pipes connects with headbox diffusing chamber. Stock directly enters distributing element of headbox from diffusion chamber. Damping element of distributor can even stock flow, disperse fiber flocs, attenuate pulse of stock flow and release dissociative air in stock. So stock can feed into mixing chamber through damp element evenly. Every small section stock flow from damp element may be fully mixed in mixing chamber. Fiber flocs can be further dispersed and pressure fluctuation of different stock flow can be eliminated in mixing chamber. Stock outlets are evenly distributed in circumference of equipressure distributor and in the same altitude, so every stock flow has the same pressure and flow velocity. Additionally the length of every flexible pipe connecting distributor with headbox is equal, so every stock flow entering into headbox through distributor also has the same pressure and flow velocity. These characteristic ensures that stock can uniformly enter headbox and don’t has any transverse flow in headbox. This kind of flow can’t affect fiber orientation. Besides the top of distributor has overflow outlet that can stabilize flow pressure and reduce pressure fluctuation. On the other side foam can discharge from overflow outlet.  

    Compared with conventional tapered header distributor, the characteristic of equipressure distributor is as follows:

1) equipressure distributor can be made more easily and with higher process precision. It also can be used more conveniently.

2) Stock is directly fed into headbox through equipressure distributor and stock flow doesn’t need change its direction abruptly. This can avoid bad influence on stock distribution and fiber orientation from flow direction change suddenly.

3) Stock can enter headbox with the lower velocity and this makes stock can flow in headbox with velocity ratio of 4:1[2]. So stock can flow with bigger acceleration ratio in headbox with equipressure distributor than with conventional tapered header distributor. Equipressure distributor can satisfy volume requirement of headbox to the wider extent and improve profile basis weight of old headbox.

4) It doesn’t have any influence on stock feeding into headbox with equal pressure and velocity whether the overflow outlet of equipressure distributor is close or not and size of overflow outlet. But when stock enters headbox through tapered header distributor, we need adjust distributor overflow to maintain pressure equilibrium in cross machine and too large or too small a distributor overflow will affect fiber orientation and stock distribution. Therefore equipressure distributor does much better in ensuring stock distribution uniformly in cross machine than conventional tapered header distributor.