Heat exchange of
water undergoes a complex chain of reactions resulting in both
alkaline and acid scaling. Flow dynamics, quality of water, pressure
variations and complexity of chemical reactions make predictions
difficult. This scaling phenomenon is directly related to alkalinity
and hardness in which heat exchange provides the trigger point for
this chain to begin. Alkaline scale formation begets from the
decomposition hydrolysis of bicarbonate ion as process temperature is
increased. Starting withReaction
A (3
HCO3 - + 3 H2O ↔ 3 CO3² - + 3 H2OH+). Once the solution is heated,
alkalinity in form of bi carbonates combines with water to form CO3²
and hydronium ions. This results in immediate variations in pH values
and resultant inability to accurately predict scale and sludge
formation. In Reaction
B (CO3 2- + Ca2+ →CaCO3
↓) Carbonate ions then combine with Calcium ions to form a compound
that forms hard scale on the contact surfaces. At Reaction
C (2 CO3²- + 2 H2O ↔2
HCO3 - + 2 OH-), carbonate ions combine with water to produce bi
carbonates and hydroxyl ions. At Reaction
D (2 OH- + Mg2+ →Mg
(OH) 2 ↓), the short lived hydroxyl ion cycle quickly combines with
magnesium ions to form a precipitate of magnesium hydroxide. It is
assumed that steps A to D support deposition of calcium carbonates
ahead of magnesium. At Reaction
E (3 HCO3 - + 3 H2OH+
→6 H2O + 3 CO2 ↑), hydronium ions react with bicarbonates to form
water and carbon dioxide lowering the localized pH conducive to acid
scaling of silicates and sulphates, a much harder form of scale. This
step is probably related to the pressure fluctuations inside the heat
exchange tubes. At Reaction
F( 4HCO3 - + Ca2+ +Mg2+ →CaCO3↓+ Mg (OH)2 ↓+ 3CO2 ↑+ H2O) a
double reaction of calcium and magnesium precipitate in the given
order forming carbon dioxide and water again leading to acid scaling
of silicates and sulphates. This is one explanation why scaling occurs
as honeycombs.
Some of the most
glaring effects of EcoBeam XL are:
Changes in pH.
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There are rapid changes in pH of water due to formation of negative
ions, bicarbonates and carbon dioxide. However, the common practice
is that pH values of solutions are measured from samples drawn out
of heat exchanger tubes of recovery section and not conclusive.
EcoBeam XL will stabilize the pH through creation of additional
hydrogen and hydroxyl ions and obviate the use of complicated and
impractical pH monitoring. These ions, combined with flow dynamics
will remove all existing scale in the system accessible to this
energized water and inhibit future scaling and corrosion. The sludge
formed thereof will be carried away by the flow of the water.
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Scaling and Hydro
Dynamics.
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Though the explanation above caters for the likely chemical
reactions, it ignores the aspects of hydro dynamics created due to
heat, flow of water and additions of chemicals in water to control
scaling and corrosion. Molecular clusters of water carrying their
own electrical charge as well as that of the dissolved solids within
them intersect each other’s electrical fields while passing through
valves, housings and surfaces creating turbulence. The rapid rise
and fall in temperatures act as initiators of another chain of
chemical reactions that would constantly be different at different
nano seconds. Scale precipitation inside tubes is not only from
initial scale formation under pressure but also due to nucleate
recirculation due to recycling. EcoBeam XL will stabilize all
chemical reactions, separate all peripheral dissolved solids that
form scale and enhance the performance of the plant under varying
flows and temperatures. The electrical energy (zeta potential) of
the scale forming compounds will be used to stabilize pH and form
soft slimy sludge instead of hard alkaline and acid scale. At the
same time it will be the silicates that shall initiate the process
of acid sludge while the other sludge will collect around it.
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Reduction in
Pressures and Role of Carbon Dioxide.
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Formation of carbon dioxide raises the pressure inside the vessels,
affecting formation of steam. Some combines with it to make the
water acidic. In case of EcoBeam XL, Hydrogen Ions being positive
will form a pattern along the surfaces of pipes and chambers. Carbon
dioxide formed will convert to carbonic acid which in turn will
deplete the hard scale. Because most of the CO2 will be utilized to
deplete scales as a result, pressures in the vessels will reduce.
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Corrosion.
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The formation of hydrogen ions and them being attracted to the
sidewalls of the pipes that are ground negative besides removing
existing hard scales also forms a thin film by reacting with
existing corrosion to reverse the damage and inhibit further
corrosion not only in the tubes but also throughout the system.
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