◆To check relative partial element of system to find pollution.

Repairing method is as following:

◆To clean membranes element and adjust, correct or amend pre-treatment

◆ Suitable material may be used to replace system tube.

C, Scaling

   The scaling is a kind of chemical problem of deposition of small solution or difficult solution salt, which creates commonly at last stage and spreads slowly to front stage. Raw water with Ca, carbonate or sulfate shall plug system in several hours because of scaling. But deposition with barium and F shall form slowly, for their low concentration.

  To analysis deposition according to following steps:

★      To check raw water quality under condition of system design restore.

★    To analysis the composition of Ca, barium, strontium, sulfate, F,

silicon, pH value, salt water LSI and sea water S & DSI and calculate

the quality balance of ion of the above-mentioned matters.

★       To check system whether deposition is in concentrated water.

★     To take out the last membranes element, if it is weight like stone

with serious pollution.

  Observing deposition crystallization under microscope, if it has foam meaning carbonate pollution. To analysis deposition through X-ray.

  Repairing method:

★   To clean it with LD-811 and LD-812 cleaner and analysis ion

composition of solution cleaned.

★   To optimize cleaning method accordance with deposition.

★   Against to carbonate, reducing PH value of water-input and adjusting

filling volume.

★ Against to sulfate, reducing restoring volume and adjusting filling

volume and variety.

★   Against to fluoride, reducing restoring volume and adjusting filling

volume and variety.

1.3 Lower water-output volume low salt-penetrate volume

  A, Membranes pressure fastened

After membranes pressure fastened, water-output lower and salt- escape raises, next situation shall cause membranes pressure fastended:

★ Water-input pressure is too high.

  ★ High temperature

★ Water hammer

 If air in system, high-pressure pump starts, water hammer shall creates. Damaged membranes element must be replaced or add new membranes element with system end.

ring of resisting to machinery stress to support overall wrap of 8inch membranes element. For smaller diameter membranes element, it is through water-output pipe and self anti-stress to avoid overall wrap remove.

C, Membranes surface destroyed

Front element is destroyed often by crystallization in raw water or metal matter with sharp edge. If water-input with such matter, for example: weld crumbs, which will make membranes surface destroyed, against this problem, no affective method except pre-treatment. Replace all destroyed elements.

D,At any condition, if pressure is higher than water-input or concentrated water 0.3bar, compound membranes layers will be separated.

After opening membranes fans destroyed from water-output pressure, crack will appear at overall layer of membranes parallel along to water-output pipe, and near to adhesive location of membranes bag. Membranes’s crack will appear at three places of water-input, outer side and concentrated water side.

 2.2 High water-output volume high salt- penetrate volume

 A, Membranes oxide

If salt-escape volume reduces and water-output volume is high, it means membranes is destroyed. The front membranes element is easier than other location to be damaged by last Cl, bromine, ozone and other oxide matter, specially under condition of neural alkali PH value.

If do not obey PH value and temperature limited and sterilize with oxide reagent, all elements will be destroyed.

 Once membranes element is destroyed, they must be replaced with new ones without other method.

B, Leak

  Membranes element or water-output center tube machinery damage will cause water into or concentrated water into water-output, specially higher with pressure raising.

3, Strong pressure drop

 High different pressure between water-input and concentrated water or named △P will create strong blocking along to water flow from membranes element. When using 8 inch membranes element, the affection will be passed through glass steel overall wrap of neighboring elements in pressure volumes, then the last element will withstand largest trust.

Before start, there is air in system, membranes element will appear water hammer and water impact. When stopping system operation, it must confirm vacuum in pressure volume.

Pressure drop between water-input and concentrated water is measured point of water flow clocking via system, it based on flow rate and temperature of membranes element water-input flow tube. So to keep water-output and concentrated water constant, in order to verity membranes element pollution at operation.

 A, Short current in safe filter

   Safe filter can block big impurities to avoid blocking on input tube of front membranes element. Filter core installs unfastened, no connector in filter core or lost, it will cause plug of membranes element. Fiber filter can not be used, for their easy to solution.

  B, Filter penetration of pre-treatment medium

   Sometimes, minor powder through sand, multilayer filter medium, activity carbon, weak ion charge resin or diatoms will enter into and plug front membranes element.

  C, Scaling

   Scaling will cause pressure drop raising at end of membranes element, so it must be controlled properly and cleaned with suitable medicine.

  D, Sealing ring destroyed

Sealing ring destroyed will cause raising of pressure drop without regularly. Some water-input will not enter through membranes element, thus it exceeds Max. restored volume of membranes element. This situation will cause plug at element and neighboring element.

  E, Bio pollution

Bio pollution will cause pressure drop raising at front of membranes system. Bio membranes is common colloid pollution and very viscous, it will block strongly to water-input.

  F, Inhibition deposition

   When compound organic antiscalant meets multivalent cation, e.g Al or left compound cation coagulation, it will deposit as colloid and waste seriously membranes element of front part. The pollution is difficult to be cleaned. So it must be cleaned repeatedly with LD-812 Cleaner.