Download Concept Scalewatcher

Scalewatcher
®
Hard water treatment system
THE MYSTERY OF ELECTRONIC WATER TREATMENT UNVEILED
Introduction
The problems of scale are well known to those living and working in "hard" water areas. Scale is the
undesirable consequence of water supplies becoming super-saturated with dissolved minerals. These
problems are of greater significance if found in industrial water systems and commercial buildings.
Scaling problems commonly occur, even in "soft" water areas, when a fluid stream is circulated, liquid
losses causing concentration of the dissolved mineral ions and eventually forcing the minerals to
precipitate at their solubility limit.
In process industries, it is common for chemicals to be added either because the water is being used for
'scrubbing' or cleaning, or to achieve a chemical/mineral effect as part of the production process, so
increasing the scaling tendency. Scaling deposits are very common in flow lines subject to changes in
pressure or temperature. Regardless of how hard water effects are achieved, the outcome is the same for
all. Scale fouling results in reduced diameter or blocked pipes, reduced heat transfer efficiency, seized
pumps, inoperable valves, misleading meter readings, defective heating elements etc.
Supersaturation
Aqueous solutions can become supersaturated, which means that they contain higher concentrations of
dissolved solute than their equilibrium concentration. Such solutions are not stable and are easily
triggered into dropping back to saturation level, forcing the dissolved compound to precipitate. Even
when a bulk solution is less than fully saturated, scale formation can occur spontaneously due to
localized super saturation, at a surface for example.
pH Effect on Scale Formation
The pH of the solution is directly related to its acid content (typically carbonic acid). The higher the acid
content, the lower the pH number. The solubility of calcium carbonate is directly affected by the pH of
the water. If the pH of the water is decreased, more calcium carbonate solid can be dissolved.
Conversely, if the pH of the water rises, it will force calcium carbonate out of solution and hence scale
deposits will form.
Temperature Effect on Scale Formation
Gases in general, and specifically carbon dioxide, are less soluble in water at high temperatures.
Therefore, as the temperature rises, the dissolved carbon dioxide decreases. This increases the pH of the
fluid, reducing the solubility of the calcium carbonate and forcing the mineral to deposit.
Pressure Effects on Scale Formation
Carbon dioxide and gases in general are more soluble under higher pressure. Therefore, as the pressure
drops, carbon dioxide gas will be forced out of solution, lowering the carbonic acid concentration. The
rise in pH is associated with a drop in calcium carbonate solubility, leading to the formation of mineral
scale deposits.
ScalewatcherElectronic Water Treatment
The patented Scalewatcher EWT, is a non-invasive system utilizing a solenoid coil or coils wrapped
around the pipework to be treated. A signal generator of which the frequency is continuously changed
supplies current to the coils. The pulse shaped current creates an induced electric field, concentric
around the axis inside the pipe. As a consequence to this arrangement, any charged particle or ion
moving within the field experiences a so called Lorenz force generated by the interaction between
charged particles and magnetic and electric fields. Research at a major University in Philadelphia
confirmed that the Lorenz Force is unchanged, irrespective of flow rate. Generated magnetic fields have
been measured and have been found to be below 1 Gauss, lower than the earth magnetic field strength.
This technology overcomes one major disadvantage of permanent magnet devices, viz, that they work
well only within a certain flow rate ‘window’ and that at higher and lower flows the performance drops
to zero.
Scalewatcher EWT affects the formation of scale by increasing the homogeneous precipitation rate of
calcium carbonate and certain other minerals. The ability to adjust power, frequency and coil
configurations on site enables performance to be optimized with no downtime and no pipe replacement.
Operating Mechanisms of Electronic Devices
Current scientific literature describes the macro effects, which are the consequence of fundamental
interactions between applied fields and precipitating substances. The amount of energy that is introduced
by a solenoid coil is very small (the consumption of a house hold Scalewatcher unit is one order of
magnitude less than a cordless telephone). To study the induced fields, scientific tools of high precision
are needed which do not interfere with the interactions that we want to measure. The atomic force
microscope (AFM), capable of examining growth patterns on surfaces at the highest resolution, is a tool
that can demonstrate some of the key interactions.
To understand the mechanism, some knowledge of mineral scale precipitation is necessary. We know
that in order to form a scale deposit three conditions must be met;
1. The solution must be supersaturated with mineral ions.
2. Nucleation sites must be available at the pipe surface.
3. Contact / residence time must be adequate.
To prevent scale it is necessary to remove at least one of these pre-conditions. Clearly contact time is not
an alterable factor. To be effective any device must therefore affect either the super saturation value or
the nucleation process.
The direct effect of the electronic device described above is on the nucleation process and in particular
to enhance initial nucleation through the creation of new nucleation sites within the bulk fluid flow. We
call this controlled precipitation. Crystal growth then occurs at these points of nucleation and not at the
pipe wall. Suspended solids increase with a corresponding drop in the level of super saturation, and these
effects have been observed in the field.
(See table 1)
A Lorenz force F is experienced by charged particles that flow through a field:
F = qE + q (V x B) where q is the charge on the particle, E is the electric field vector, V is the particle
velocity vector, and B the magnetic field vector. Electronic devices operate at very weak magnetic fields
whereas magnets need high field strength (>1000gauss) for optimum performance. The flow
dependency of magnetic devices is explained by the velocity parameter, V, and E=0. The flow nondependency of electronic devices is explained by the fact that the force of the electric field component is
independent of the flow rate. This suggests that the key performance parameter is the total value of the
‘Lorenz’ force acting on the charged particles, rather than the individual magnetic and electric field
vectors.
By nature all particles in water have a negative charge and are surrounded by the so called
“electric double layer”, layers of positive and negative ions around the particle. These layers
may be seen as “protective” layers preventing more ions to stick to the surface of the particle.
The Lorenz Force, if strong enough, will distort these layers and ions in the bulk of the liquid
may now stick to the surface forming crystals. These crystals will not adhere to pipe walls and
will go down the drain or remain suspended in a circulating system. As a result less mineral ions
will be present in the liquid. An important side effect is the fact that pipe walls corrode less as a
lower amount of positive ions are present. Ends
NOTES TO EDITORS
1. The Scalewatcher is an environmentally friendly technology.
2. As 40% more energy is needed to heat water in a system fouled with scale, Scalewatcher also helps to
reduce energy costs.
3. Launched in the 1980’s it has successfully treated hard water problems for industrial manufacturers as
well as water companies, oil producers, farmers, horticulturists, shipping companies, shopping
centers, school, universities and government establishments.
Table 1
Lorenz Force
•EWT: F=q(E + vxB) Newton
•Magnet: F=q.vxB Newton
•Alloys: F=q.E Newton
F: Lorenz Force expressed in Newton
q: Charge of particle expressed in Coulomb
E: Electric field expressed in Volt/meter
V: Velocity of particle expressed in meter/second
B: Magnetic induction expressed in Tesla.