Transcript Scale and Bacteria Control Comparison Between

Scale and Bacteria Control Comparison Between
BacComber and Chemical Treatment
Chemical
Descaling and
fouling
1.
Scale control
principle and
side effect
1.
2.
2.
3.
Scale control
effectiveness
1.
Bacteria
control
principle and
side effect
1.
2.
2.
3.
4.
5.
Bacteria
control
effectiveness
1.
2.
3.
BacComber
Cannot perform descaling on existing
scale present in the cooling system.
Chemical and other deposit will build up
over period of time.
1.
Use chelating agents such as phosphate
to prevent formation of hard calcite
scale.
Phosphate promote growth of bacteria
and algae.
Overdose causes calcium phosphate
which inhibits heat transfer. Uneven
coverage due to under-dosing can cause
localized corrosion attack
1.
ULF waves used to form water
cluster to reduce the formation of
calcium carbonate. Scales that
may form is non-sticking aragonite
soft scale instead of the surface
adhering calcite hard scale.
For effective scaling control, usually TDS
is controlled at below 1000 ppm.
Control of scale at higher TDS level not
recommended.
1.
Scale control is effective even at
high TDS level of up to 3000
ppm. However, maximum TDS limit
must be within authority sewerage
discharge control limit.
Use biocide to control bacteria
Chemical dosage is based on certain
assumed cycle of concentration, which is
difficult to control.
Scale controlling agent such as phosphate
promotes bacteria growth which may be
out of control when biocide dosage is
low.
Most biocides are highly corrosive and
will corrode the metal members in the
cooling system.
Environmentally unfriendly
1.
Uses copper and silver ions to
control bacteria and alter the
DNA to prevent bacteria
multiplying. In addition, the ULF
treatment controls and enhances
the overall bacteria control
effectiveness.
Non-corrosive and
environmentally friendly.
Bacteria control effectiveness varies with
the dosings.
Effectiveness depends on the other
chemicals introduced during treatment.
Ineffective in controlling bacteria that are
under the chemical deposits, scales and in
the biofilm.
1.
2.
2.
Ability to remove existing scale in
the cooling system.
No chemical and other deposit
could build up due to descaling
effect and absence of chemicals.
NOTE: The Copper & Silver Ions was the 1 st
generation system & was obsoleted many years
back. The latest 3rd generation that has started to
commission in 2011 is ULF+Emitters system.
2.
Effective and continuous control of
bacteria in the water.
Effective in controlling bacteria in
biofilm and under the scale and
deposits. The descaling effect of
BacComber system will remove the
bacteria under the scale, deposit,
biofilm and inhibit their growth.
Comparison Between BacComber and Chemical Treatment:
Corrosion, algae, slime control and cost effectiveness
Chemical
Corrosion control
principle and side
effect
1.
Corrosion control
effectiveness
1.
2.
2.
Algae and slime
control
1.
2.
3.
Water saving
1.
2.
Energy saving
1.
2.
BacComber
Using corrosion inhibitor such as
phosphate to control corrosion.
Phosphate is nutrient to bacteria and
algae. Hence can promote bacteria
and algae growth, microbial
induced corrosion.
1.
Using ULF wave to generate water
cluster to reduce the formation of iron
oxide and in addition, promote the
formation of corrosion protection
magnetite layer instead of nonprotective hematite when iron oxide is
formed.
Excessive biocide can cause severe
corrosion.
Excessive chemical can cause pitting
or under-deposit localized corrosion.
1.
Absence of chemicals, hence no
"created" corrosion problems.
Effective in algae control but subject
to environment conditions.
Excessive phosphate will promote
algae growth.
Slime and biofilm control
effectiveness vary between dosing.
1.
Effective in algae control but subject
to environment conditions.
Very effective in slime / biofilm
control because of descaling effect.
Heavy water consumption due to
heavy bleed off to control the
desired cycle of concentration or to
maintain the TDS level.
Drained off water cannot be
recycled due to chemical content.
1.
Well treated system can maintain
the energy consumption.
Unable to remove the existing scale
and deposit hence cannot further
reduce energy consumption.
1.
2.
2.
2.
3.
Great water saving, because of
ability to maintain higher cycle of
concentration compared with chemical
treatment. Water saving cost can be
more than the treatment cost.
Water can be recycled as it does not
contain chemicals. Further saving can
be achieved if recycled.
Very effective in descaling the existing
scales hence further reduce the energy
consumption.
Energy cost saving usually more than
treatment cost.
For new cooling system, low energy
consumption level can be maintained.
Economy
1.
Recurring perpetually
1.
One time investment with a payback
time not between 16 to 24 months.
Safety, health
hazard,
environment and
ISO 14000
consideration
1.
Environmentally unfriendly, cost of
handling and storage of chemical is
high. Dangerous to be handled and
stored by staff.
1.
Very safe, environmentally friendly, no
health hazard, no handling and
storage cost.