Siemens IONPURE VNX50HH-2, Руководство по эксплуатации и техническому обслуживанию

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IONPURE
®
VNX50HH-2 CEDI Modules
Page 22 IP-MAN-VNX50HH2
The system can be cleaned and sanitized with any of five (5) different solutions, depending on what
needs to be removed:
•
Hydrochloric acid (2%) –
For removing scale and metal oxides.
•
Sodium chloride/sodium hydroxide (5% brine/1% caustic)
– For removing organic
foulants and biofilm.
•
Sodium percarbonate –
For removing organic foulants, reducing pressure drop, and
sanitizing.
•
Peracetic Acid –
Used for routine sanitizing to discourage the growth of bacterial films.
•
Aggressive Multi-Agent cleaning for Biofilm–
Recommended for general biofouling with
increase in pressure drop. This aggressive cleaning protocol consists of 5% sodium chloride
followed by a 2% sodium hydroxide and then followed by a 1% sodium percarbonate with a
final 5% sodium chloride flush. The combination of these treatments performed sequentially
has proven to be more effective than any single treatment performed separately.
•
Aggressive Multi-Agent cleaning for Fouling/scaling –
Recommended for fouling and
scale remediation with drop in performance combined with increased electrical stack
resistance. Aggressive sequential cleaning protocol of salt (5% sodium chloride) then
followed by caustic (2% sodium hydroxide) followed by acid (2% hydrochloric acid) with a
final 5% sodium chloride flush (
see Service Bulletin 2007-02 ). Extended soaking or
increasing the acid concentration in the range from 2%-4% HCl based on the severity of
electrical stack resistance increase increases the benefits of this treatment.
NOTE: If you are unsure whether the module is scaled or organically fouled, clean first with brine, then
caustic clean followed by acid clean.
6.8. Cleaning with 2.0% Hydrochloric Acid (HCl)
Hydrochloric acid is a corrosive chemical. Wear safety glasses, gloves, and
protective clothing when using this or any corrosive chemicals.
Cleaning with Hydrochloric Acid involves three steps:
1. Hydrochloric acid treatment (2% HCl),
2. A salt flush (5% NaCl), and
3. Water flush.
STEP 1: Recirculating the HCl Solution
NOTE:
This is the minimum amount of HCl required. It may be necessary to use additional HCl
to effectively clean a scaled Module. Monitor the pH of the solution during the
recirculation period. If the pH begins to rise, add more HCl to maintain a pH of
approximately 0.5.
Circulating HCl through the system removes scale and metal oxides
from the module.
Chemicals necessary for Step 1 (2% HCl) VNX50-HH
Water (RO permeate or CEDI product) 99 gal (375 liters)
36.5% Hydrochloric Acid (HCl) 4.2 gal (16.2 liters)
NOTE:
The following cleaning procedures are based on the piping setup shown in
Figure 6-1.
1. Prepare the VNX system for chemical cleaning. Follow the instructions in Section
6.5 and 6.6. Make sure the tank drain valve is closed.