AQUAPHOR APRO 1000 LPH, Руководство пользователя

Страница: 65 / 83

65
10.5.4 HIGH SOLUTE PASSAGE
High solute passage at normal permeate flow may have different causes.
1. Leaking O-Ring
Leaking O-rings can be detected by the probing technique.
O-rings may leak after exposure to certain chemicals or mechanical stress, e.g., element movement caused by
water hammer.
The corrective measures are:
▪
If one pressure vessel shows a significantly higher permeate concentration than the other vessels of the
same stage, then this vessel should be probed.
▪
Inspect O-rings of couplers, adapters, and end plugs for correct installation and as-new condition.
▪
Replace old and damaged O-rings.
▪
Proper shimming of the elements in a pressure vessel is essential to minimize the wear to the seals.
2. Telescoping
APRO elements can be mechanically damaged by telescoping, where the outer membrane layers of the element
unravel and extend downstream past the remaining layers. A modest telescoping does not necessarily damage the
membrane, but the glue line and/or the membrane can be ruptured in more severe cases. Telescoping is caused
by excessive pressure drop from feed to concentrate.
10.5.5 QUICK GUIDE (TABLE)
Changes of the permeate flow, the salt passage and the differential pressure are symptoms which can be attached
to specific causes in many cases. Although, the symptoms of different causes may over-lap in reality, and the
symptoms are more or less pronounced in specific cases.
Permeate
flow
Salt
passage
Differential
pressure Direct cause Indirect cause Corrective measure
⇑
→
Oxidation
damage Free chlorine, ozone, KMnO
4
Replace element
⇑
→
Membrane
leak Permeate backpressure; abrasion Replace element, improve
cartridge filtration
⇑
→
O-ring leak Improper installation Replace O-ring
⇑
→
Leaking
product tube Damaged during element loading Replace element
⇓
Scaling Insufficient scale control Cleaning, scale control
⇓
Colloidal
fouling Insufficient pretreatment Cleaning, improve
pretreatment
↓ →
⇑
Biofouling Contaminated raw water, insuffi-
cient pretreatment Cleaning, disinfection,
improve pretreatment
⇓
→ →
Organic
fouling Oil; cationic polyelectrolytes wa-
ter
hammer Cleaning, improve
pretreatment
⇓
↓ →
Compaction Water hammer Replace element or add ele-
ments
Increasing
↓
Decreasing
→
Not changing
⇑
Main symptom