Revamp Forced Circulation Evaporator Waste Water Stream
|Application||Forced Circulation Evaporator Waste Water Stream|
|Fouling Issue / Frequency|
The evaporator being revamped was the 1st effect of a 4-effect evaporator train to treat waste water from a plant that produces dyes for textile. This 1st effect experienced severe fouling by crystallization of a variety of sulfate salts. Effect 2 to 4 experienced some fouling but to a lesser extent. Due to fouling, within only 20 days of operation, the plant regularly lost more than 50% of its treatment capacity.
|Solution / Approach|
For the revamp into the self-cleaning configuration, the heat exchanger was equipped with an inlet channel to feed the particles and distribute them over all tubes. In between the heat exchanger outlet and the entrance of the flash vessel a particle separator was installed to separate the particles from liquid and transport them via a central down-comer back to the inlet. In the revamp the existing heat exchanger bundle was re-used, changing it from a 3-pass into an once-through configuration.
|Medium||Waste Water Dyes Process||Condensing Steam|
|Pressure||2.2 bara||1.59 bara|
|Flow||900 m3/h||2659 kg/h|
Number of Tubes
Length of Tubes
34.9 mm (ID)
After taking the plant back into operation, the evaporation capacity kept constant, which results in increased production, lower downtime and reduced maintenance cost.