|
|
|
Approach flow
|
|
Stable conditions for stock deaerator
The approach flow connects the stock preparation with the paper machine. At this stage the stock is diluted to concentrations of 0.2 ... 1.4 % and a stable flow is achieved. Among other things, the quantity and the flow speed of the fibres are controlled and any unwanted substances are removed via final filter stages in screens and cleaners. An especially important element is the deculator (stock deaeration unit) upstream of the headbox. Under vacuum it removes the residual air and ensures minimum pulsation and constant pressure in the headbox.
|
Level measurement with VEGADIF 51
For optimum efficiency and quality, the stock deaerator must always maintain a defined level. A continuous measurement guarantees a constant level and protects the downstream headbox pump from running dry. The levels are often only 1.5 m (5 ft) with a vacuum up to -0.08 bar (-1.16 psig). The sudden deaeration causes foam generation on the surface, but nevertheless, the accuracy must remain in the mm range. The optimum solution for continuous level measurement is the VEGADIF 51 differential pressure transmitter with capillary lines and flush flange isolating diaphragms.
|
|
|
|
|
|
|
|
VEGADIF 51
- flush flange isolating diaphragms
- high accuracy
- reliable function even with foam generation
|
|
|
|
|
|
|
|
|
|
|
|
Netherlands
