PHYSICAL WATERCONDITIONERS

How Effective Can They Be ? A Presentation for ASPE

Jonny Seccombe

President

Aqua-Rex LLC

3301 Spring Mountain Rd Ste 18

Las Vegas NV 89102

949 887 2170

Learning Objectives

- Understand the Chemistry of Hard Water- Effects of Scale on Plumbing Systems- Ion Exchange Softeners – Pro’s & Con’s- Alternatives to ‘Salt’ Softeners – PWC’s -

How Physical Water Conditioners Work- Design – PWC location effects performance - Summary

The ChemistryCalcium Bicarbonate

(Dissolved)

Ca (HCO³)²Becomes

Ca CO³ Calcium Carbonate +(Solid)

CO² Carbon Dioxide +

H²O WaterTo Treat Hard Water - Either get rid of

Ca (Calcium) or HCO³Bicarbonate

TemperatureAbove 130 F

Pressure Drop

pH Increased

DUE TO

“Scaling Events”

Scale Sticks to Surfaces

Scale has to form onto something

It won’t spontaneously form onto itself

It has to have a surface or nucleation seed to form onto

Meldrum & Sear – Now You See Them

Science VOL 322 19 December 2008

Scale Sticks to Surfaces – So

• Plant Lifecycle Costs Increase – maintenance, replacements, flow rates

• Energy is Wasted– Limescale is 400 times less conductive of Heat than Copper. 1/8” of scale equates to 12% loss in heating efficiency,

• Pumps have to work harder in constricted pipes

• Hygiene is Worse – Scale traps dirt so cleaning is more difficult. Locker Rooms, Assisted Living, Dorms, Water Features

• Legionella Greater Risk – scale harbors bacteria

Regular Water Softeners Remove calcium by

“Ion Exchange” •Resin beads in Tank dosed with Salt

•Excellent Results

•Well proven technology

• But

•Requires Regular Dosing with Salt

•Plant Costs and Space useage

•Maintenance and Servicing

•Potability – Elderly and Infants

•Softener Bans – Chlorides!

Quote!“It’s a long time since I put in a pure

softener system”Paul Jolly

Senior Public Health EngineerWSP Group – Flack and Kurtz

July 2008Probably 95% of water treatment in Public Buildings,

Schools, Hospitals, Hotels & Defense Establishments In UK

is now done by

Physical Water Conditioners

Physical Water Conditioners

Create nucleation seeds that encourage scale to form in suspension rather than encrust surfaces.

•Nucleation Seeds – Many forms such as Zinc, Iron (Fe), Silico Phosphates plus others – some not yet identified.

Physical Water Conditioners

• Stimulate scale formation in SUSPENSION in the Water

• Instead of ENCRUSTATION on Surfaces

• The scale floating in the water is harmless – its good for you when you drink it

Two Stage Process•Stage One – Create the nucleation seeds

•Stage Two – Use a “Scaling Event” to create the scale on the nucleation seeds.

The closer together, in terms of time and distance, that these two events occur the

more effective the treatment is likely to be.

There is no detectable difference in the water, or its content, after stage one.

Magnetic / Electrolytic

•DC current or Dissimilar Metals•Corrodes Zinc (Coetzee et al.)

•Creates Zinc Hydroxide seeds•But•Finite amount of corrosion•Passivity – water quality?•Limited Effective Life•Unless Anodes are Cleaned or Replaced

Template Assisted Crystallization

• “New” Technology Using “Seeding” Media

• Conventional Tanks • Low Maintenance • But• Vulnerable to Contamination from Cu, Fe, Cl & Phosphates• Not clear when media replacement is required• Unpredictable Performance• Unreliable due to changing water quality• Withdrawn from UK market by Lifescience

Products due to lack of predictability

Electronic/Electromagnetic•Some induce an electro magnetic field

others Induce an electric charge•Act on ions already in the Water•Some Treat Static Water•Some Remove Existing Scale•Some are Non Intrusive –easy to retro fit•But•Durability of stage one can be limited•Effectiveness reduced in “clean” water•Correct Location on layout is VITAL

Factors to consider when Locating an

Electronic Water Conditioner

Cold Water Tanks – Cisterns

Booster Sets

Circulation Pumps

Re-circulating Systems – Cooling Towers Swimming Pools

Hot Water Return

Cold water services to mixing valves

ox

Primary

Secondary

Heat

Exchanger

Heat Exchangers

Water Heater Design is Significant –Do the scale particles accumulate in the bottom of the tank or does the incoming water stir it up? Can it get drawn from the tank into the water heater?

Find the Pump !

HOT

WATER

TANK

Can a Physical Water Conditioner

Soften Water?

If a device can stimulate scale formation in suspension and increase the amount of precipitation that takes place

Then

There will be less Calcium Bicarbonate dissolved in the water

The water will therefore be chemically softer although total calcium remains the same

It will behave like partially softened water

Weeks from 1 - 12

50ppm

Residual Calcium Bicarbonate

in Hot Water

100ppm

A WORD OF WARNING !!!!

Make sure YOU know what you are buying

It is quite possible that the Manufacturer doesn’t know what he is actually selling!

SummaryCalcium Bicarbonate (dissolved) makes water hard.

Calcium Carbonate (particulate) is formed when precipitation occurs – the scale once formed is effectively inert.

PWC’s use a Two Stage Process – They create Nucleation Seeds then a “Scaling Event” is needed to create the scale.

Magnets/Electrolytic Systems generally dose zinc hydroxide

Electronic/Electromagnetic – Act on salts already in the water. Location is critical

Preventing scaling using PWC’s -

Reduces energy consumption and lifecycle costs

Promotes hygiene & reduces the risk of legionella

Can produce most of the benefits of conventional water softeners but without generating chloride effluent - and at lower cost