/ BENEFITS EVALUATION TRADITIONAL VS AUTOMATIC BIOCIDE TREATMENT BY BIOSHIELD
The goals that can be achieved by using of
BIOSHIELD are:These goals are connected: in fact
the economic saving correspond to the increase of the thermic efficiency of
the condenser and so of the coefficient of heat exchange, that is in inverse
proportion to the thickness of the biofilm on the surface of the tubes. The
respect of the environment instead, consist in the minimum introduction of
chemicals (biocide or other biocides) in order to eliminate the deposit of
bacteria on the surface of the tubes.
- economic saving
- respect for the environment
Today, in order to decide the quantity and
length of the treatments, it consider the due experience by comparing the
executed procedures with the recorder effects of Biofouling and you make
continual or semi-continual injections of biocide.
It is remarkable that only a residual part of
biocide carries out its biocidal action, because a fixed percentage reacts
instead with the organic substances in the water.
The quantity of these substances can’t be
easily estimated, since it depends of many factors (temperature, climate,
currents, suspended deposits).
Therefore the procedure of continual injection
has the following limits:
- it effects its biocidal action also when it is not necessary, i.e. when
there are not bacteria to eliminate
- for economic and environmental reasons it is necessary to made it in
bland concentrations so it is always efficacious.
The procedure of semi continual
effects its biocidal action in statistically” but not “certainly”
- it is executed in bland concentration and for the same reasons of above.
of BIOSHIELD allows to optimize the duration of the treatments by
measuring directly and univocally the thickness of the bacteriological
deposit, responsible of the coefficient of heat exchange.
Besides the certainty to avoid any waste of
chemicals primes a vicious circle in which one can test and use biocides in a
smaller quantity and for less time and these biocides will be always more
efficacious and potent (always in the limit of the law).
On the other hand, a good treatment of the
devices implies more respect for the environment because treatments that are
controlled in quantity and quality diminish the introduction of toxicals in
The fundamental idea of BIOSHIELD is
that to measure the level of bacteria in order to put into action of biocide
treatment only at the right moment and
for the necessary time. This principle lead to a strong saving of chemicals
because it is well known that the biocide injected to obtain a biocidal effect
accomplishes only in part this duty while most of it reacts with the organic
substance in the water. Minimizing the length of the injections means to
minimize this waste.
now make a few quantitative consideration by comparing the traditional
techniques of injections of biocide (continual and semi-continual) with the
one of automatic injections ruled by BIOSHIELD.
hour a Q1 quantity of biocide will be injected; a decimal fraction
of Q1 will react with the organic material, in the pipe. So
at the entrance of the condenser there will be a quantity of biocide:
Q1 - Q1d1
the coefficient of the reacting biocide)
quantity of biocide will effect its biological action inside of the condenser;
therefore, on coming out, there will be a quantity of biocide:
= Q2 - Q2d2
) = Q1 (1-d1
the coefficient inside of the condenser
similar to d1)
the phenomenon recurs in the
stretch of the pipe going from the condenser to the drainage. So we have:
Q3 - Q3d3=
)= Q1 (1-d1
the coefficient d
of the characteristics of the system (length, section,
capacity, etc.) and on other variable quantities (temperature of the
water and of the ambient, kind of water, etc.).
for environmental and legal reasons, at the drainage it must be valid the
Q4= Q1 (1-d1
the hypothetic semi-continual chlorination we will have a quantity of biocide
that is consumed and introduced in the environment.
h=8,760 in the continual
h=4,380 in the semi-continual one)
how much will be the quantity of biocide used with the automatic chlorination
technique controlled by BIOSHIELD.
let in the system a quantity of biocide Q’1
exactly like the last case we will have likewise to the previous
case a quantity of biocide in the output
up by the accustomed condition:
the total value of the chemical introduction in the environment will be:
h is the length of the checked treatment)
the experiences and the research ( see International Conference of London in
1994) suggest in 10 – 15 days the time necessary in order the thickness of
the bacteria layer is like that to obstruct the heat exchanger and in 4 –40
hours the time necessary to destroy that layer.
have so that the length of the treatments has a value of:
is into the range:
improvement of the productivity:
= QTOT / Q’TOT
= h / h’
the hypothesis to use the same concentration of biocide normally used:
= Q 1,
the following condition:
= QTOT / Q’TOT = h / h’
produce also a possible increase of the quantity of biocide used in the unit
of time, thereby if i.e. it should decide to double the concentration of
biocide used to obtain a shock effect, we will have at any rate.
a cost of installation of BIOSHIELD B
= 19,250 USD and 3 real cases of reference in which it consumed biocide for a
value of C1 =82,500
USD: one other for a value of C2=165,000
USD and the last for a value of C3=275,000
we have a total annual cost installing BIOSHIELD
= Cn /
n = 1,2,3)
compare to the precedent costs gives at the end of the first year of
use a save of
= Cn -
n = 1,2,3)
in the 3 cases to:
by BIOSHIELD it has the opportunity to make biocide treatments
potent, more efficient, more short and economical with a less environmental