Appendix 4 – Glossary of Terms #
The following list includes terms and abbreviations used in this document.
Reverse Osmosis – A water purification technology that uses a semi-permeable membrane to remove dissolved substances from the water.ย In reverse osmosis, an applied pressure is used to overcome osmotic pressure, forcing water molecules to pass through the membrane while all dissolved solids remain in the feed water side of the membrane.
Transfer Pump (Re-Press Pump) – A pump that delivers RO water to a wash, which is run by a command from the wash tunnel
Production Pump – VFD pump that matches the pump speed with municipal water pressure, to ensure the system delivers maximum RO water to the tunnel.
Thin Film Composite Membrane (TFC) – Thin Film Composite (TFC) membranes are a special type of RO membrane which offers high efficiency, long life and resistance to most adverse water conditions.
The membrane material is very sensitive to free chlorine. If the feed water is chlorinated a chlorine pre-filter must be used to protect the membrane.
Free chlorine must be controlled to 0.00 PPM level as even 0.1 PPM will damage membranes.ย The DOW/Dupont membranes have a 1,000 hour life at 0.1 PPM free chlorine level in the feed water. Damage accumulates proportional to the free chlorine level.
A failure in the carbon filter (chlorine removal) will quickly lead to a membrane failure which will require membrane replacement.ย Verifying that the carbon filter is operational is a critical maintenance check to avoid damage or failure of the membranes.
Municipal Feed Water – The incoming water supply which is directed into the membrane for processing.
This water must be pre-conditioned to meet the membrane manufacturerโs water requirements to prevent damage to the membrane.
Pre-treatments may include water softening, chlorine removal, sediment filters, and other chemical treatments based on the water analysis of the wash site.
Product Water (RO Product) – The purified water that has been separated from the feed water stream by the reverse osmosis membranes.
Recovery โ The amount of RO Product water produced as a percent of the total amount of feed water.
Example:ย If the system feed flow is 20 GPM and the RO Product produced is 10 GPM, then the recovery would be 50%.
This RO system has been designed for a maximum of 65% recovery.ย If the reject water is not being recycled for other wash purposes, the recovery can be increased by replacing the 10 GPM flow orifice with a 6 GPM orifice.
This change would reduce the maximum feed water rate to 16 GPM and increases recovery to 62.5 %.
Because the Reject water (or concentrate) is normally re-used in other wash operations the recovery is set to 50% to 65%.
Reject Water (RO Reject or Concentrate) โ The portion of the feed water that does not pass through the RO membrane and is delivered to the Reject Tank.
This water has a higher level of impurities than the municipal feed water and is captured in storage tank for other uses in the wash system. This flow rate is set by a reject line orifice and does not require adjustment.
Percent Rejection โ The percentage of TDS removed from the feed water.
Membranes typically reject greater than 99.5 % of the dissolved solids which are present in the feed water.
Example: If the incoming feed water is 200 TDS, the RO water will measure approximately 1 ppm TDS.
Dissolved Solids (TDS) โ Municipal water contains dissolved solids (calcium, magnesium, etc.) at levels which may vary dramatically over the course of a year depending on the water source and treatment methods.
Contact your local water supplier to understand the water quality, and water treatment sanitizing approach used throughout the year.
TDS is measured in parts per million (PPM).ย The innovateIT RO system is designed to operate with feed water with TDS levels up to 1000 PPM which is much higher than general municipal water standards.
Parts Per Million (PPM) โ PPM is the standard measure of total dissolved solids where 1 PPM is equivalent to 1ml / Liter of liquid.
The RO membranes remove 99.5% of the dissolved solids from the water.
Using typical water, this unit should produce water with TDS of 1 to 5 PPM.ย As the membranes age, the TDS will normally increase.
Generally, TDS levels below 20 PPM will provide a spot free rinse.ย Above 20 ppm the operator will see visible outline on glass or dark painted if water spots are allowed to remain on the surface.
TDS levels above 40 PPM will leave spots on cars so it is critical that the system be checked on a daily basis to ensure proper water quality.
Membrane Flush Cycle โ RO membrane flush cycle starts 15 minutes after the tank is filled (flush cycle only starts if the wash tunnel do not demand RO water from the unit).
innovateITโs system uses RO water to flush the membrane for longevity of the membrane also reduce scaling build up.