VEGA

Cellulose production

Cellulose production

Bleaching process

To achieve the desired degree of whiteness, the pulp must be bleached. For this purpose it is fed into bleaching towers up to 25 m high via pumps, stock distributors or screw conveyors, depending on the density of the material. The bleaching process runs continuously at temperatures up to +95 °C with bleaching chemicals such as oxygen, ozone or peroxide. The bleached pulp is then discharged via screw conveyors. Due to its enormous size, the bleaching tower is never emptied. Similar bleaching processes are used for mechanical pulp bleaching and waste paper de-inking.

Level measurement with VEGAPULS 68, overfill protection with VEGACAP 64

Optimal bleaching quality requires a constant level in the bleaching tower. This is guaranteed through a level measurement in conjunction with automatic discharge control. The powerful radar sensor VEGAPULS 68 provides reliable measuring results, even under the difficult measuring conditions in the bleaching tower. And the capacitive level switch VEGACAP 64 serves as an additional safeguard against overfilling.

Level measurement with VEGABAR 54

The level measurement in the extraction area is realized via the pressure transmitter VEGABAR 54 with ceramic CERTEC® measuring cell in a ball valve fitting.

» VEGAPULS 68

Measuring range
up to 75 m
Process fitting
thread from G1½, 1½ NPT
flanges from DN 50, 2"
Process temperature
-200 … +450 °C
Process pressure
-1 … +160 bar
(-100 … +16000 kPa)
Measurement accuracy
+/- 2 mm
SIL qualification
up to SIL2

» VEGACAP 64

Version
fully insulated rod
Measuring range
up to 4 m
Process fitting
thread from G¾, ¾ NPT
flanges from DN 50, 2"
Materials
316L, PTFE
Process temperature
-50 … +200 °C
Process pressure
-1 … +64 bar
(-100 … +6400 kPa)

» VEGABAR 54

Measuring cell
MINI-CERTEC®
Measuring ranges
-1 … +72 bar
Permanent product temperature
up to 120 °C
Deviation in characteristics
0,2 %, 0,1 %
SIL qualification
up to SIL2