Table 2
Chemical cleaning in place (CIP) procedures applied at the three locations studied.
| | Location | Location I
Sas van Gent, Netherlands | Location II
Dordrecht, Netherlands | Location III
Veendam, Netherlands |
| | Linear flow velocity | 0.184 m s−1 | 0.202 m s−1 | 0.202 m s−1 | | Feed pressure | 1 bar | 1 bar | 1 bar | | Total duration | 8 hours | 24 hours | 6.5 hours | | Step1 | Circulation with NaOH
60 min; T = 35°C; pH = 12 | Circulation with NaOH
120 min; T = 35°C; pH = 12 | Prerinsing with demi water | | Step2 | Soaking with NaOH
30 min; T = 35°C; pH = 12 | Soaking (overnight) with NaOH
T = 20°C; pH = 12 | Soaking with demi water
30 min | | Step3 | Circulation with NaOH
60 min; T = 35°C; pH = 12 | Rinsing with demi water | NaHSO3; pH = 10.5 (adjust pH with NaOH)
60 min; T = 35°C; C = 1–1.5% v/v | | Step4 | Soaking with NaOH
30 min; T = 35°C; pH = 12 | Circulation with Divos 2
90 min; T = 35°C; pH = 1.6 | Soaking with NaHSO3
120 min; T = 20°C; pH = 10.5 | | Step5 | Circulation with NaOH
60 min; T = 35°C; pH = 12 | Final rinsing with demi water | Rinsing with demi water | | Step6 | Soaking with NaOH
30 min; T = 35°C; pH = 12 | | Divos 2
30 min; T = 35°C; pH = 2.5 | | Step7 | Rinsing with demi water | | Soaking with Divos 2
60 min; T = 20°C; pH = 2.5 | | Step8 | Circulation with HCl
60 min; T = 35°C; pH = 2.1 | | Final rinsing with demi water | | Step9 | Soaking with HCl
30 min; T = 35°C; pH = 2.1 | | | | Step10 | Circulation with HCl
60 min; T = 35°C; pH = 2.1 | | | | Step11 | Soaking with HCl
30 min; T = 35°C; pH = 2.1 | | | | Step12 | Final rinsing with demi water | | |
|
|
demi water = dimineralized water (RO permeate); Divos 2 = mixed acid detergent descaler (JohnsonDiversey, UK).
|
