Current international shrimp
prices are quite low, due to many factors. Import restrictions from China, low
cost export of shrimp to USA from South American countries like Ecuador, etc.
Moreover cost of feed and labor has increased drastically over the last couple
of years, while selling price has reduced drastically. Both these are causing enormous pressure of
cost reduction on the aquaculture farmer, especially the shrimp farmer.
As a farmer, you don’t have
control on the selling price of shrimp which is largely dependent on
international prices and decided by processing units.
However you can control the input
costs.
The 3 largest input costs for a
shrimp farm are:
- Cost of feed
- Cost of seed
- Cost of aeration
Good quality feed and good
quality seed cannot be compromised. However the cost of aeration can be reduced
to a large extent – by almost 60% - if proper equipment is used. Diffused
aeration is very often found to be 3 times more energy efficient than paddle
wheel aerators.
Most large fish and shrimp farms
use paddle wheel or similar surface aeration methods. Such aerators spend
almost 75% of their energy in moving the water, rather than aeration. They are
really water movement devices, although one calls them aerators.
Artificial aeration is efficient
only when the surface area available for interaction between the air and water
is high, and the time of contact is long. With paddle wheel aerators, the drops
of water are quite big – almost 5 to 20 mm big. And the splash down in a very
short time.
Compared to this, diffused
aeration provides very fine micro bubbles in the water using highly efficient
airoxi tube and blowers. The bubbles are about 1 mm in diameter. And they
further breakdown into even finer bubbles in salt water used for shrimp
culture. In fact the floc in the ponds and nurseries increases the efficiency
of aeration, so diffused aeration using blowers and aeration tube increases in
efficiency as the culture time increases.
A comparative table of efficiency
is given below. As you can see – blower and airoxi tube / aeration tube
diffused aeration is highly efficient and the high SOTR (Standard Oxygen
Transfer Rate) is almost 3 times that of paddle wheel aerator. This makes the
SAE (Standard Aeration Efficiency) very high and translates into saving of
electricity cost of almost 60%.
And this is after considering
that you use the paddle aerators to move water – but only 1 hour x 4 times a
day.
To ensure a good balance, use the
paddle wheels only as water moving equipment, and not for aeration. Let the
blower and aeration tubes give you the required aeration.
You can even calculate your
aeration requirement for your shrimp nursery or shrimp farm using the online
aeration calculator on www.airoxi.com/calculator
Comparative performance of AirOxi TM Products v/s Paddle
Aerator
(Comparison
based on market feedback from customers)
|
Parameter |
AirOxi TM Tube
with piping and blower |
Paddle Aerator |
|
Type of
aeration |
Fine Bubble Diffusion (1mm and less) |
Mechanical and surface ,
through droplets (20 mm) |
|
Numbers required per Hectare |
250 mtr / 5 HP blower and piping |
8 nos x 2 HP each |
|
Total Power required / hectare for
average stocking density |
5 HP |
16 HP |
|
Biomass supported / HP |
1000 Kg per HP. |
350 Kg per HP |
|
Approximate Initial Cost |
1.5 to 1.8 lacs (blower, piping, AirOxi Tube, etc) |
2.40 lac (30,000/- x 8 nos) |
|
DO – Kg / Hour / HP |
3.6 Kg / HP / hour |
1.2 Kg – 1.4 Kg / HP / hour |
|
Average DO levels observed in similar
conditions |
Day time – 8.5 to 9.0 Night – 5.0 to 6.0 |
Day time – 7 to 7.5 Night – 4.0 to 5.0 |
|
Time taken for same increase in DO (SOTR
- Standard Oxygen Transfer Rate) |
20 minutes |
60 minutes |
|
Power Cost (considering industrial power
at 7/- per unit) – operating 20 hours a day, for 3 months use in a season. For AirOxi tube – we are also considering 1 HP x 4 nos of
paddle aerator for water circulation |
47,250/- for Oxygenation 3,780/- for Water movement (2 hours) Total – 51,030/- |
1,51,200/- |
|
Stocking Density possible because of high
DO |
High to very high |
Low to medium |
|
Noise Levels |
Very low |
High |
|
Operate during feeding time |
Yes |
No |
|
Moving parts and maintenance |
Very Low |
High |
No comments:
Post a Comment