A cooling system can have visible scale and still be a poor candidate for an electrolytic scale remover if the water load, bypass flow and cleaning plan are undefined. The useful question is how much scaling material the unit can remove under measured site conditions.
Electrochemical softening can promote precipitation near a cathode, but that does not mean every cooling loop will achieve the same percentage hardness removal or eliminate all existing scale. The reactor’s job must be defined within the full water-treatment program.
The short answer: Provide circulating and sidestream flow, make-up and blowdown, hardness and alkalinity, conductivity, pH, temperature, cycles and current treatment. Ask for a mass-balance and pilot acceptance plan covering removed solids, energy, cleaning and downstream scale indicators.
1. What does an electrolytic scale remover actually remove?
Electrochemical softening uses reactions at electrodes to create local conditions where hardness salts can precipitate. Research on electrochemical precipitation illustrates that deposit formation and cleaning are part of the process, not incidental maintenance. The equipment should be assessed by the mass removed and its effect on the real loop—not by a claim that electric current makes all scale disappear.
Clarify whether the project seeks lower dissolved hardness, reduced future deposition, improved heat transfer, lower chemical use or removal of existing deposits. Those are different endpoints. A sidestream reactor may treat only part of circulating flow; its per-pass result cannot be reported as whole-system removal without accounting for recirculation, make-up and blowdown.
2. What baseline is needed before sizing?
Collect representative analyses of make-up and circulating water: calcium and magnesium hardness, alkalinity, pH, conductivity, temperature, chloride, silica and any chemicals or suspended solids relevant to the plant. Record make-up, evaporation and blowdown rates, cycles of concentration, heat load and equipment currently fouling. One lab sample from a quiet day may miss seasonal or operational variation.
| Site input | Why the supplier needs it | Risk if missing |
|---|---|---|
| Hardness and alkalinity load | Sets potential precipitate and required removal rate. | Reactor selected by flow alone. |
| Sidestream and total flow | Separates per-pass treatment from whole-loop effect. | Inflated system-level claim. |
| Chemicals and pH control | Can change precipitation and materials exposure. | Unanticipated fouling or corrosion. |
| Existing scale and cleaning history | Separates removal of dissolved load from old deposits. | Wrong expectation for recovery time. |
Where the plant already has filtration or chemical dosing, describe how the new reactor will interact with it. An electrolytic unit may complement, not automatically replace, every other treatment step. The water-treatment owner should approve any change to corrosion-control or biocide practice.
Convert the water analysis into a daily load before comparing equipment. The relevant quantity is not only concentration in a sample but concentration multiplied by make-up or treated flow over time. A higher-flow site with moderate hardness can impose more solids-handling work than a smaller site with higher concentration. If evaporation and blowdown vary seasonally, size and trial conditions should cover the period that governs the buyer’s problem.
3. What defines reactor capacity?
Ask for treated sidestream flow, residence time, electrode area, current/power range, pressure drop and control strategy. Capacity stated only in cubic metres per hour says little about hardness mass removed. If the supplier proposes a bypass, show its takeoff and return points so the treated water actually mixes with the loop.
The unit also needs compatible piping, isolation valves, drain, electrical supply and safe access. A reactor that can process the water but cannot be taken offline for cleaning will create operational risk. Check materials against water chemistry and the maintenance chemicals used.
Ask what fraction of the loop passes through the reactor in each operating mode, including reduced pump flow. A bypass mounted where little water actually circulates may produce a good outlet sample but have negligible whole-loop impact. Flow measurement and a simple piping diagram are therefore part of the buying evidence, not optional installation details.
4. Where do the precipitated solids go?
Precipitation transfers material from water into deposit or suspended solids. The purchase must describe removal: cathode scraping or cleaning, collection, filtration, purge and waste handling. If solids remain in circulation, a reduction in dissolved hardness at the reactor outlet may not translate into lower heat-exchanger fouling.
State cleaning trigger, expected interval under the design load, labor and consumables. A supplier’s maintenance interval from another water source may be a starting hypothesis, not a warranty for this site. If polarity reversal is proposed, include how it affects electrode wear and cleaning performance.
The removed material needs a destination. Check whether it is captured in the vessel, a downstream filter or a drain stream, and whether the site can handle that stream under its own waste rules. A maintenance plan should say how operators verify that the cell is clean enough to return to service and how loss of performance is detected before heat-transfer equipment starts fouling again.
5. How should a field trial be judged?
Define inlet and outlet sampling points, test duration, flow, current, energy and solids mass or another defensible removal measure. Collect loop-level data too: make-up, blowdown, scale tendency, pressure drop or heat-transfer indicators where measurable. A single lower-hardness outlet sample is not proof of a sustained system benefit.
Record changes in chemical dosing and operation during the trial. If those change at the same time, the cause of an observed improvement is harder to identify. Set a baseline period and an acceptance method with the site water-treatment team before equipment is installed.
One useful trial scorecard tracks hardness load in, captured solids, electrical energy, cleaning time and an agreed downstream indicator. The measurements do not all have to improve by the same percentage. For example, a unit might remove measurable solids yet consume too much operator time for the site’s economics. Define what counts as success before anyone sees the data.
6. How can supplier offers be compared?
Compare a full delivered treatment package: reactor, power/control cabinet, pumps if needed, valves, solids removal, instruments, skid, installation and commissioning. One price may cover only the electrode chamber. Compare cost against the site-specific mass load, energy, cleaning and measured benefit rather than an unsupported “percent scale reduction.”
The HELE electrolytic scale remover page is a starting point. Exact capacity, electrode life, maintenance and savings require the buyer’s water data and a defined validation plan.
7. What should the RFQ include?
- Cooling-system drawing, total and proposed sidestream flow, operating schedule.
- Make-up and circulating-water analyses with seasonal ranges.
- Current chemical treatment, cycles, blowdown and fouling baseline.
- Electrical/piping constraints, solids disposal and cleaning access.
- Pilot endpoints, measurement methods and included installation/commissioning scope.
Questions buyers often ask
Does electrolysis remove existing scale from every heat exchanger?
Not automatically. The unit may reduce scaling constituents in treated water; existing deposits and heat-exchanger recovery need separate assessment.
Is outlet hardness reduction enough to prove the project?
No. Measure sustained flow, energy, solids removal and loop-level outcomes against a baseline.
Can a sidestream unit be rated from total circulating flow alone?
No. The side-flow fraction and hardness mass balance are needed to assess whole-loop impact.