Ion Exchange service and maintenance

TWA is able to provide the below services in order to maximize the performance and the lifetime of the Ion exchange service and maintenance:

  • Ion exchange resins loading and unloading service
  • Vessels inspection
  • Performance evaluation
  • General maintenance

General information:

  • Supplied resin:

Check that the resin types and quantities which were supplied are identical with the resins which were ordered according to the resin specification or the manufacturer’s recommendations.
It is essential that the resins are filled into the correct vessels.

  • Preliminary Vessel Inspection

If available check plant documentation and vessel drawings. If not available, record technical data of the vessels including vessel diameter, cylindrical shell height, type of distributor system, type and number of nozzles, density of nozzles, height of collector system, position of sight glasses etc.
When an old resin bed is being replaced it is essential that, before the new resin is installed, the unit is first inspected to ensure all the old resin and any debris has been removed completely. Removal of debris, any old underbedding, and old resin can be done by the siphoning technique.
Also important is that the vessel internals have been checked to ensure there are no signs of damage, blockage, or excessive movement in the distribution and collection systems.
It is recommended – where possible – to check the pressure drop of the empty filter at the service flow rate.

  • Resin Loading:

Loading and unloading ion exchange resins from vessels can be done in a variety of ways, depending on the equipment design and procedures developed at the site.
One simple means of transferring resin is through the use of eduction systems.

  • Water quality:

Wherever possible use demineralized water for the filling and commissioning processes.
Where this is not available fill, regenerate and commission cation vessel first in order to produce decationized water for the filling and commissioning of the anion vessel.
Use of raw water can result in magnesium hydroxide precipitation in contact with caustic or OH- form anion resin.

  • Extra technical information:

Storage and Handling of Ion Exchange Resins
Ion exchange resins are normally shipped in the water-swollen form and should be stored in a sheltered area and in a manner whereby the moisture within the beads is retained.
The resin may be stored in the plastic bag in which it was shipped, provided it is kept tightly sealed or transferred to a glass container.
Although freezing does no harm, repeated freezing and thawing should be avoided.

  • Microbiological protection:

Micro-organisms (algae, bacteria, etc.) can proliferate in plants shut down for prolonged periods, if conditions in the plant (temperature, presence of organic matter, pH, etc.) are favourable for their growth.
The slimes arising from this proliferation may choke the resin bed and cause flow, quality and capacity problems.

  • Backwash all resin beds to remove debris and suspended contaminants. Keep the resin in the exhausted rather than regenerated form. If necessary, convert the resin to the completely exhausted form, using dilute solutions of acid for the anion resin, caustic soda for strongly acidic resins.
  • Rinse all resins with clean water.
  • If organic contamination is suspected, clean anion resins with alkaline brine.

If necessary, disinfect resin beds before restarting the plant.

Softener service and maintenance

TWA is able to provide the below services in order to maximize the performance and the lifetime of the softeners

  • General maintenance, including valves inspection and maintenance (fleck and clack amongst others)
  • Resin unloading and loading
  • Vessel inspection

Inspection, maintenance, replacements and resin load and loading can be carried out by visits on-site by our trained technicians who are able to provide all the technical supports in order to achieve the best results.
If required, all the necessary spare parts can be provided by TWA.