|
LENZING Technik
>
Engineering & Contracting
>
Fasertechnik
>
Viscoseaufbereitung
>
Viscoseentlüftung
VISCOSEENTLÜFTUNG
For continuous de-aeration of viscose in order to avoid spinning problems:
Features
- Debottlenecking by replacing existing film de-aerators
- Long cleaning intervals
for minimum down times
extremely stable process, due to no interruptions
nearly no loss of efficiency during life
- Reliable and stable operation
- Large surface area due to packing materials
for better de-aeration
for minimum energy consumption
In Detail
GENERAL
As a consequence of the previous processes, viscose contains dissolved air, in addition to small quantities of air bubbles. The bubbles have to be removed from the viscose prior to spinning so as not to lower the quality of product.
Because of the vacuum of around 20-25 mbar absolute the viscose boils at a temperature of between 17 and 23°C, which allows the residual air to be extracted.
Water also evaporates out of the viscose which produces a temperature drop(Dt) of several degrees between the intake and the outlet.
The temperature drop can be varied for different viscose qualities in order to reach the quality requirements for various applications.
LENZING TECHNIK DESIGN
Unlike normal film de-aerators, where the de-aerating surface is on the inside of the tank, the Lenzing de-aerator has a much larger surface area due to the metallic packing inserts at the top of the tank.
This provides the benefit of much better de-aeration at the same Dt, or a lower Dt for the same de-aeration efficiency, thus providing a much lower energy consumption.
Additionally, the system works much more reliably and is more stable because soiling of the surfaces reduces the effective de-aeration area by only a small amount. Thus the de-aerator can be operated for several months at optimum performance.
In our experience the de-aerator has to be cleaned once to twice per year. For further minimising of the downtimes we recommend that you to have a second, standby, insert, ready to replace the soiled one, which can then be cleaned after restarting operation with the standby.
|
