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Reverse Osmosis System Cleaning Ⅱ

Table 1, pH value and temperature range of clean medicine 

    Data                              clean medicine

Temperature/      40      35        30          25

 PH value        3~10      2~11       2~11.5         2~12 

5, Medicine volume of RO membranes

  Accordance with next two calculating method to decide volume of clean box and clean volume:

5.1 Net volume of pressure volume and net volume of clean system tube may be calculated according to (1) V clean medicine=1.2(V pressure volume+ V cleaned system pipe).

5.2 Calculation method of membranes element type and fouling situation:

  For commonly fouling: each membranes of Ø10.16 cm(4”) mated with 8.5-9.5L clean medicine. each membranes of Ø20.32 cm (8”) mated with 34L clean medicine.

  For serious fouling: each membranes of Ø10.16 cm (4”) mated with 16—19L clean medicine, each membranes of Ø20.32 cm (8”) mated with 55—69L clean medicine.

6, Form of anti-infiltration clean system

To combine chemical clean equipments and anti-infiltration system into a completed clean system(attached Diagram 1). If anti-infiltration system operates nominally, it will be cleaned once or two times in per year. Provisional clean method may be tried.



反渗透清洗储存罐 RO clean store jar

清洗泵           clean pump

过滤器           filter

反渗透装置       RO device

浓水             concentrated water

渗透水           RO water

Figure 1 Schematic diagram of reverse osmosis cleaning system

7, RO membranes clean method

7.1 Low pressure clean

 Cleaning RO membranes assembly and system pipe with RO medicine under pressure 0.4MPa.

7.2 Chemical procedure

 A, Cleaning liquid is mixed with RO medicine in store jar and adjust temperature and system pipe.

B, To start up cleaning pump, empty all remained water and primary cleaning medicine

Repeated cleaning over one hour. At first term, clean flow may be controlled in 1/3 of Max. flow, and then raise to 2/3. At last term, flow will be maximum. During clean term, if PH value is less than 0.5, the medicine will be added. Total time of LD-811 medicine will not be more than 20 minutes. After this term, first residue in anti-infiltration system and clean system will be emptied and renew deploy the second acid medicine.

Table 2   Max. cleaning volume in each pressure container

 

Dia. of membranes pressure container   pressure of clean liquid   flow rate of clean liquid        / cm                   / MPa              /(L.min) 

10.16                0.15~0.4            18~38

20.32                0.15~0.4            60~151

C, If necessary, cleaning and immersion may be turning used. Immersion term may e as 18 hours. If is need for more than 10~15 hours or whole night, for keeping procedure temperature, it may be used with 10% flow rate in tale 2.

D, After chemical clean, washing with anti-infiltration water.

E, If need, repeat the above-mentioned procedure

F, Two stages of RO system will be cleaned in order to avoid oil pollution renewadsorption to second surface stage.

G, After cleaning, washing with 0.4MPa pre-treatment water for 15~60 minutes.

H, After system renew to operation, primary water must be emptied. When electric conductivity and PH value arrives procedure requirements, RO system may begin to operate. For making quality of water-output stabilized, several days will be necessary in resume.

8, Emergent clean

If the system is not cleaned immediately, system pressure dropP raises two times and standardized water-output volume down into 50%. The common method is difficult to clear the fouling, thus the offline may be used. The membranes element polluted serious will be take out from system and cleaned with chemical and physics medicine and detectors in special clearing equipments manufactured by our company. The membranes element will be inspected before and after cleaned, it must be certified in arriving product index and contract requirements and renew to be used in system for operation.

For assuming membranes element operating normally in system, our company offer hundreds of spare membraness with high performance may be replaced in user’s system

site.

9, Assessment on clean effect

 To assess the effect on anti-infiltration membranes, it is noted with dialysis water rate restore index (r), formula as following (2):


R=       JQ     ×100%              (2)

         J0

In where, JQ means anti-infiltration membranes dialysis water volume after cleaned

        J0 means primary volume of anti-infiltration membranes

  10, Long term commitment of service

  For assuming the normal operation for long term, our company will form the agreements with consumers for them to repair the RO system. We will collect affective operation data, visit consumers regularly, offer standardized system information and suggest the best operation plan for users with optical disk.
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