 |
 |
PRODUCTION
PROCESS of Electrochlorinator |
 |
|
 |
ELECTRO
CHLORINATOR
(On-Site Sodium Hypochlorite Generator) |
 |
 |
 |
 |
 |
| Electrochlorinator requires only salt, water
and electricity. |
| Electro chlorinator Provides the power of
Chlorine without the danger of storing or handling
hazardous materials. |
| Sodium hypochlorite generated
on-site does not degrade like commercial sodium
hypochlorite. |
| The total
operating cost of Electrochlorinator is less than the conventional Chlorination
methods. |
| On-site generation
of sodium hypochlorite allows the operator to produce
only what is needed and when it is needed. |
|
|
|
 |
Pristine Water Electro-Chlorinator is a disinfection alternative
that small water treatment systems will find beneficial because it
is cost-effective, easy to produce and eliminates potentially dangerous
handling and storage problems associated with other types of disinfection
practices. On-site Sodium Hypochlorite (NaOCl) generation requires
only salt, water and electricity to produce sodium hypochlorite actually
needed. Unlike conventional 12 to 15 percent purchased hypochlorite,
which will degrade over a course of time, Sodium Hypochlorite generated
on-site will maintain its strength.
Within the Electrolyzer, the brine solution- which is a good conductor
of electricity- supports a current applied between the positive and
negative electrodes, thus electrolyzing the sodium chloride solution.
This results in chlorine (Cl2) gas being produced at the positive
electrode (anode), while sodium hydroxide (NaOH) and hydrogen (H2)
gas is produced at the negative electrode (cathode). The chlorine
further reacts with the hydroxide to form sodium hypochlorite (NaOCl).
This reaction can be simplified in the following manner: |
 |
NaCl
(Salt) |
+ |
H2O
(Water) |
+ |
Electricity |
= |
NaOCL
(Sodium
Hypochlorite) |
+ |
H2
(Hydrogen) |
|
 |
| In
the process of on-site Sodium Hypochlorite generation 1 kg of equivalent
chlorine can be generated from 4.5 kg of salt and 4 kilowatt hours
of electricity. The final solution consists of approximately 0.8 percent
sodium hypochlorite. |
 |
Advantages
of On-Site Generation of Sodium Hypochlorite |
 |
Although
the economic consideration is the major advantage in using On- site
generated Sodium Hypochlorite over the use of other forms of Chlorination,
but the technical advantages are even greater.
The following are some of the problems associated with using commercial
grade liquid sodium hypochlorite. These have high concentration (10-12%)
of active chlorine. These are produced by bubbling gas chlorine in
Caustic soda (Sodium Hydroxide). They are also commonly called as
Liquid Chlorine.
Corrosion
The corrosion due to Commercially produced hypochlorite is a concern
because of its effect on equipment. A 10 to 15% hypochlorite solution
is very aggressive due to its high pH and chlorine concentration.
Because of its aggressive nature, the hypochlorite solution will exploit
any weakened areas in the hypochlorite piping system and may cause
leaks.
Scaling
The formation of calcium carbonate scale is another concern when using
commercial grade liquid hypochlorite for chlorination. Commercial
grade liquid hypochlorite has a high pH. When the high pH hypochlorite
solution is mixed with the dilution water, it raises the pH of the
mixed water to above 9. The calcium in the water will react and precipitate
out as calcium carbonate scale. Items such as pipes, valves and rotameters
may scale up and no longer function properly. It is recommended that
the commercial grade liquid hypochlorite not be diluted and that the
smallest pipe lines, the flow rate will allow, should be used in the
system.
Gas Production
Another concern with commercial grade hypochlorite is gas production.
Hypochlorite loses strength over time and generates oxygen gas as
it decomposes. The rate of decomposition increases with concentration,
temperature, and metal catalysts.
Personal Safety
A small leak in the hypochlorite feed lines would result in the evaporation
of the water and in turn the release of chlorine gas.
Chlorate Formation
The final area of concern is the possibility of chlorate ion formation.
Sodium hypochlorite degrades over time to form the chlorate ion (ClO3-)
and oxygen (O2). The degradation of the hypochlorite solution is dependent
on the strength of the solution, temperature, and the presence of
metal catalysts.
Decomposition of Commercial Sodium Hypochlorite can be created by
two major ways:
a). The formation of Chlorates due to high pH, 3NaOCl= 2NaOCl+NaClO3.
b). Chlorine evaporation loss due to temperature increase.
Therefore, for any given strength and temperature, over a period of
time, the higher strength product will eventually be lower in available
chlorine strength than the lower strength product, since its decomposition
rate is greater. The American Water Works Association Research Foundation's
(AWWARF) concluded that the decomposition of concentrated bleach (NaOCl)
is the most probable source of chlorate production. High concentration
of Chlorate is not advisable in drinking water.
Chlorine Comparison Chart
 |
 |
 |
| Product Form |
PH Stability |
Available Chlorine |
Form |
| C12 gas |
Low |
100% |
Gas |
| Sodium hypochlorite(Commercial) |
13+ |
5-10% |
Liquid |
| Calcium hypochlorite granular |
11.5 |
20% |
Dry |
| Sodium hypochlorite(On-site) |
8.7-9 |
0.8-1% |
Liquid |
|
|
|
| |
Now
which is the ideal disinfectant?
- Chlorine Gasthis is too dangerous to handle and
not safe in residential areas. Most of the times, they are not
available.
- Bleaching Powderor Calcium Hypochlorite is effective,
but the whole process of mixing, settling and disposing off of
the sludge is very messy and cumbersome. This makes the whole
area dirty. More over, the bleaching powder absorbs moisture during
monsoon or in wet surroundings and emits chlorine gas, making
the bleaching power lose its strength.
- Liquid Bleachor Liquid Chlorine -or Sodium Hypochlorite
is very effective. This is in liquid form so very easy to handle.
But the commercially available Liquid Chlorine is not only expensive
but looses its strength over a period of time and becomes water.
The danger of spillage is a common problem.
- Electro ChlorinatorVery effective, very economical,
very safe, and easy to prepare and use. Latest technology.
|
 |
|