|
Topic |
Question |
Answer |
|
Aero-Tube
thickness |
AeroTube seems to be more thicker
than those of competitors. Can you
explain why? |
a thicker wall
could add durability to the
product. Thinner walled product
wears out and oxidizes faster. |
|
SAE |
Why is SAE
higher in salt water than in fresh
water?
|
because in salt water, you get
smaller bubbles probably because of
the density of the water(surface
tension).
Smaller bubbles transfer more oxygen
than larger ones. Smaller bubbles
also rise slower in the water so
they have longer to transfer O2 to
the water. |
|
Durability |
What is an estimated duration of
Aero tube? |
many
of our customers
kept using the aero-tube for
four to
five years. But
after several years of continuous
usage, the tubing should be replaced
to maintain the maximum efficiency
and oxygen exchange, |
|
Hose |
In case
instaling 6 grids connected with 1
blower (3 hp) under shrimp farm
water depth 1.8 m, how long can the
main and lateral hose be extended
under blower condition of air flow
264 m3/hr (44 x 6) and air pressure
2,000 mmH2O |
Of course the
longer and the samller diameter the
hose you use the bigger the pressure
loss in hose, if the total hose is
less than 60 meters with HDPE with
one blower, the compressor lost is
acceptable. For getting real airflow
264m3/hour you need to check the
blower’s airflow curve to ensure it
can satisfy your need. 1 meter water
depth means about 10kp or 0.1kg/cm2
pressure, and
our aero-tube operation pressure is
less than 7kpa or 0.07kg/cm2. There
is some soft ware which could help
us to get the total pressure lost in
hose. |
|
Hose |
In order to
extend more, does it need more air
flow or air pressure or both?
|
Air pressure! |
|
benifit |
what's the
benefit in using aero-tube |
The aero-tube
can acheive this with a lot less
horse power that creates savings for
the farmers. What you have to do is
educate the farmers on the
following. (1) energy savings is
profit. (2) You can run the air-lift
24 hrs cheaper than you can run a
paddle-wheel for 12 hrs. (3) the
paddle-wheel cools the water down at
night where the air-lift don,t (4)
By running the air-lift 24 hrs. a
day you can get better converstion
rates which creates a higher profit
margin. You get better water quality
and keeping the DO levels higher on
the bottom of the ponds where the
shrimp live. On a test done in
Georgia in an 8 acre pond where the
air-lift was ran 24 hrs. they feed
the same rate of 250 lbs. per acre
they harvested 5000 more lbs. last
year in the two ponds over the ponds
where they just ran the paddle-wheel
at night. And the back up paddle
wheels never came on. that is more
profit for the farmer with the same
output. |
|
Durability |
What is the average durability of
the Aeration Tubing? |
The durability of the tubing is not
a problem. It does not have a very
high tensile strength but the
material itself will last a long
time. Up till now our tubing has
only been used in clean water. By
this I mean non-salt water. It has
been used for several years in
aquaculture and wast water. We have
recommended that it be changed out
every two to three years for best
performance. I don't think the
degree of salinity will make much
difference.The potential problems
comes from contamination. The pores
can become clogged from the inside
or outside. The air supply should be
clean and dry. This means having a
filter on the blower which will help
make the both the blower and tubing
last longer. Another way it can
become contaminated from the inside
is from the water itself. This
tubing should be run twenty four
hours a day-seven days a week. When
the system is turned off, water will
move through the pores to the
inside. When the system is turned
back on the air pressure will push
the water back out and any small
particles in the water can collect
in the pores. Turning the system on
and off a few times will not hurt
anything, but doing it all the time
can cause the tubing to clog to the
point where there may be excessive
back pressure making the blower work
harder and the system becoming less
efficient. The tubing can become
fouled on the outside with algae.
This is not a serous problem. All
underwater aeration devices like
ours or airstones can get a growth
of algae on them. The difference is
ours can be cleaned by rinsing with
water and the airstone has to be
cleaned in a solution of muriatic
acid. The one potential problem we
do not now about are barnacles in
salt water and what effect they will
have on the tubing. |
|
Terminology |
What are the most commonly used
terms in Aeration? |
TDS Total Dissolved Solids |
|
LRA Linear Regression |
|
NLRA Non-Linear Regression |
|
Here are some you didn't ask about
but they may come up. |
|
OTR Oxygen Transfer Rate |
|
SOTR Standard Oxygen Transfer Rate |
|
AE Aeration Efficiency |
|
SAE Standard Aeration Efficiency
(This is an important one. It is the
SOTR per unit total power input. The
higher the number the better.) |
|
OTE Oxygen Transfer Efficiency |
|
SOTE Standard Oxygen Transfer
Efficiency |
|
BOD Biological Oxygen Demand |
|
DO Dissolved Oxygen |
|
Headloss |
Compare the headloss of AertoTube to
other devices |
As compared to a soaker hose or
other aeration devices our AeroTube
has a very low headloss. This is
because it is extremely porous.
Where it take less than two "inches"of
pressure to move air through the
wall of our tubing, it may take two,
three, or more "pounds" of pressure
to move air through some of these
other devices. Because it is very
porous it takes less energy to
operate making the electric or fuel
bill for the farmer less. |
|
|
|
|
|
SAE |
Will SAE change with different
blower? |
One really important thing though
is that the SAE will NOT be the same
for every blower. Because SAE is
the # kg O2 per Hour per KW of
blower it is very dependent also on
the efficiency of the blower. Not
all blowers give the same CFM per KW
and therefore it is VERY important
that you choose the highest output
of air per KW. For example, we have
worked with Fuji and Allstar blowers
and although they are both 1
horsepower blowers, the Fuji only
gives 54 CFM and the All Star 75.
In this situation, you will have the
same energy consumption but the SAE
using these two blowers will be
completely different because of the
different flows. This is very
important to understand. |
|
Soaker & AeroTube Differences |
We have studied the samples of
soaker hose and aeration tube and
found the following differences:
a) Soaker hose has smaller OD and
thinner thickness.
b) Aerotube has smaller pinhole size
and finer surface.
Are these differences typical and
representable? Our understanding is
that fluid for soaker hose is liquid
(water) and aerotube is gas (air or
oxygen). So thinner wall for soaker
hose provides less resistance for
water to go out of the hose. Thicker
wall for aeration tube with smaller
pinholes makes air/oxygen go out
with finer bubbles and higher oxygen
transfer efficiency. |
The reasons way the soaker has the
demission it does has more to do
with economics than with function.If
it was less expensive to make a
thick wall soaker that used more
rubber and less plastic, that's what
we would be doing. We have tried to
hit a happy medium where we have a
hose that will carry water over a
long distance and be a emitter of
water at the same time. |
|
Soaker & AeroTube Differences |
Can soaker hose and aerotube be
replaced each other if efficiency is
not so much concerned. In other
words, can we make a standard
product to use as both soaker hose
and aerotube? |
It seldom works and you will have a
product that doesn't perform
well for either markets. The
aeration tubing needs to be
extremely porous to do its job and
the soaker has to be less porous to
do its job. Over the years people
have tried to use soaker hose for
aeration with very little success.
When used in aeration the soaker
will oxidize and become brittle in a
short period of time, sometimes in
less than a year. If it is used with
pure oxygen it can happen in a
couple of months. |
|
Dimensions |
Do we have only one standard
dimension AeroTube or we have more
dimension customization options to
customer? |
There is only one size which is 1". |
|
Cleaning |
Cleaning of AeroTube: As we know,
after certain period of usage, tube
pinholes may be blocked by
excrements or feeding foods. We read
from AeroTube brochure that this
tube can be cleaned simply by water.
We would like to know how cleaning
process is going on. Usually will
the users take out the whole set out
of water to rinse it? It is possible
to change the air blower to water
pump so water can go through same
channel instead of air for
cleaning? |
The function of anti-bacterial
tubing could effectively avoid the
bacterial grow on the direct surface
of inner and outer surface of the
tubing which is the main reason for
cloggy. However algae can grow on
the tubing and dust may sink on the
tubing also if the water pH is high
and Ca2+ is high CaCO3 may deposit
on the pore of the tubing. If the
above cloggy occurs you can use TCCA
or similar chemical water solution
to soak the tubing for 24 hours
which can effectively delete the
algae and CaCO3. |
|
Dimensions |
what is the maximum length of
aerotube in application? We saw some
local soaker hoses/aeration tubes
here. Air transmission loss is
significantly to be ¾ of original
intake if the length ranges from 5
to 20 meters. What is the criterion
to define acceptable or recommended
length during application? We have a
potential customer who requests
18-meter parallel tubes in his
ponds. Will this length have risk in
remaining sufficient air
transmission volume? |
We recommend the tubing NOT be over
4' to 5' in length to get the best
results. By using longer lengths
the air flow will not disburse
correctly due to the tubing be so
porous. |
|
Algae growth |
The brochure of AeroTube states that
it helps to reduce algae bloom. From
Shanghai Fisheries University this
was questioned. |
The effects on phytoplankton (algae)
are less predictable.
Destratification may reduce algae
through one or more processes: 1)
algal cells will be mixed to deeper,
darker lake areas, decreasing the
cells' time in sunlight and thereby
reducing their growth rate, 2) some
algae species that tend to sink
quickly and need mixing currents to
remain suspended (e.g., diatoms) may
be favored over more buoyant species
such as the more noxious
blue-greens, 3) changes in the
lake's water chemistry (ph, carbon
dioxide, alkalinity) brought about
by higher dissolved oxygen levels
can lead to a shift from blue-green
to less noxious green algae or
diatoms, and 4) mixing of
algae-eating zooplankton into
deeper, darker waters reduces their
chances of being eaten by
sight-feeding fish; hence, if more
zooplankton survive, their
consumption of algal cells also may
increase. While algal blooms have
been in some lake
destratification/circulation
projects, in other lakes
phytoplankton populations have not
changed or have actually increased.
For shallow lakes, it's even less
likely that complete circulation
would result in any of the
above-mentioned benefits. This is
because algae are less likely to
become light-limited in shallow
lakes, nor would water chemistry
changes be as pronounced. |
|
Nitrate levels |
The brochure of AeroTube states that
it helps to reduce nitrates levels.
From Shanghai Fisheries University
this was questioned. |
The nitrate is part of the
nitrification process of ammonia.
They have to have bacteria for the
process, in which the D.O.
(dissolved oxygen) levels will give
you the bacteria. |
|
Shellfish |
Some farmers said they are always
facing the problem that shellfish
sticks to aeration tube. How can we
prevent it and how to solve it if it
happened? |
With use Anti-Microbial Tubing I
have never heard of any problem with
shellfish sticking to the tubing. |
|
Sizing a pond |
How can we calculate the optimal
tube usage, layout and reccomended
power for blower? |
The safest way to size a pond is to
find out the maximum amount of
pounds of fish that will be in there
at any given time and the most pound
of feed that will be fed in a days
time. You need one pound of oxygen
every hour for ever 4,000 pounds of
fish and one pound of oxygen per
every one pound of feed. This will
take care of BOD loading, ammonia
and the saturation level due to the
high water temperature. If the
farmer is not having BOD and/or
ammonia problems and is using the
paddle wheel refer back to the chart
that Gerry Shell did to compare what
HP they need. |
|
Durability |
How long does the tube last? |
The material the tubing is made from
will last almost indefintely. The
problem comes with contamination
from dirty air or water. This is why
we suggest that an air filter be on
the blower and it not be cycled on
and off. The more times it is turned
off and on, the more often dirty
water has a chance clog the pores.
We recommend the tubing be replaced
every two to three years. |
|
Bubble size |
What is the size of the bubble? |
2 to 3 mm |
|
Headloss |
What is the back pressure/head loss? |
2" or 50mm plus the depth of the
water the tubing is in. |
|
Sunlight incidence |
What is the incidence of direct
sunlight/UV? Breakdown? |
This has not been a problem
here but, we have a customer in
Chile who uses the irrigation hose
in the high mountain desert and he
says if he leaves it out for a long
period of time it can become a
little brittle. This is also the
driest spot on Earth and the UV is
very high, nothing grows there. |
|
Quantity in Container |
How much tube can be shipped in 20
ft and 40 ft conatiners? |
You can get 70,000 ft on a 20 ft
container and 140,000 ft on a 40 ft
container. |
|
Stopping blower |
When you stop the blower, does the
water go into the tube?
Consequences? |
Yes eventually it will stop up,
depending on the solids in the
water. We have had it in waste water
for six years. Cycling off and on
and it is still running good. I
strongly advise the blower to run
24-7. |
|
Cleaning |
How do you clean the tube, and how
often? |
Two ways: 1) wear a pair of gloves
and wipe/rub vigorously 2) increase
your CFM for a short period of time
and that will blow off the debris. |
|
Clogging |
Sometimes they don't want to run it
24 hours a day, does it clog? |
again I strongly recommend the
blowers run 24-7, the cost to run
the blower is insignificant.
Cutting off for very long periods of
time can cause antiaerobic
bacteria as well as methane gas
(this is not good). |
|
Bacteria |
The bacteria, can it get into the
tube? |
Yes, It can be a good thing as well
as bad, if bacteria gets inside the
tubing this can cause it to clogg
up. We now have new selection to
farmers: Anti-microbial tubing which
can avoid bacterial, algea and
shellfish growth on it. |
|
Blower |
How much volume can you aerate with
a 1hp blower? |
That depends on the pounds of fish
and pounds of fed that is
being applied and also depends on
the blower's parameter( pressure and
airflow at certain pressure). |
|
Sizing a pond |
How much tube do you need for a
certain tank or pond? |
The amount of feet depends on the
CFM the blower puts out. Go to the
charts done by GSEE this is more or
less your bible to size up each tank
or pond. This is never a one size
fits all application, each one will
be a little different. |
|
Dimensions |
How long can the tube be without
losing pressure or uniformity? |
We recommend not to go over 8 foot
unless a header at each end, 3-4
foot is the best when feeding air at
both ends. |
|
Pressure |
What is the air pressure that you
need to put a fine bubble in the
air? |
Go back and study the charts by
GSEE. The lower the CFM is the
higher the oxygen transfer rate
is. Give out the numbers that we
have tested at. |
|
Salt water |
What is the reason for which the
tube performs much better in salt
water? |
sales make the oxygen molecule more
easy than in fresh water to enter in
to the water medium. |
|
Dimensions |
Is the tube available in more than
200 ft coils? |
No. The reason for this is that the
200 ft coil weighs 44 lbs, and if it
was bigger it would be difficult to
handle. |
|
Fittings |
Some people from Bangladesh and
Malaysia asked if we could provide
the fittings, as they said they
could not get fittings for our
AeroTube in their countries. |
Yes, we could provide the fittings. |
|
Headloss |
what are major differences between
Aero-Tube and other similar products |
For example from the data in the
Japanese
website(httpwww.yamatoj.comenglishuneiqpipeindex.html)
I can say that there are big
difference in SAE between our
Aero-Tube and the Japanese products.
Their products operation pressure is
0.2 kg/cm2 ( see attached 2). Ours
is less than 0.07kg/cm2. For example
if we put the two products below the
same water surface such as 1 m, the
least total operation pressure for
Japanese products is
0.3kg/cm2(0.2+0.1). And for our
aero-tube is 0.17( 0.07+0.1). For a
same blower higher pressure means
less airflow, and the airflow
difference is very big at 0.17kg/cm2
and 0.3 kg/cm2. The attached 3 is an
All Star blower's airflow curve in
different air pressure. And in our
experience, the ALL Star blower is
in high quality, but the airflow is
still changes very big facing
different air pressure. The same kw
power blower produces less airflow
with similar bubble size means low
efficiency in SAE. |
|
airflow |
You have mentioned the Air Flow rate
as 0.037m3/min per meter length,
whereas the Diffusers in practice
e.g., Dia 63mm x 1000mm Length, is
giving Air Flow rate as
0.13-0.167m3/min. Moreover, the
pressure drop, as conveyed to you is
quite less, as compared to the one
offered by you, due to reduced Dia. |
They are different equipments, the
key is SAE not airflow. 0.037m3/min
is just the best running parameter
for our aero-tube. |
|
airflow |
You have mentioned the Air Flow rate
as 0.037m3/min per meter length,
whereas the Diffusers in practice
e.g., Dia 63mm x 1000mm Length, is
giving Air Flow rate as
0.13-0.167m3/min. Moreover, the
pressure drop, as conveyed to you is
quite less, as compared to the one
offered by you, due to reduced Dia. |
They are different equipments, the
key is SAE not airflow. This flow
rate is what we have determined
provides the HIGHEST SAE overall.
The tubing can run in a wide range
of flows both below and above this
rate. If you go above this flow,
you will get larger bubbles and more
mixing of the water column but lower
SAE overall. You will still have
high oxygen transfer rates but
slightly lower rates per HP. Many
people run higher flows in the
initial phases of a wastewater
treatment system in order to do more
mixing of the water column. Then in
the later phases where they are
clarifying and “polishing” the
water, they reduce to our
recommended standard where oxygen
transfer efficiency becomes more
important than mixing the column.
The tubing is very versatile with
air flow, you can run a wide range |
|
Durability |
what is the average life of these
type of diffusers and the
requirement for it's maintenance |
Maintenance depends on the system.
They may need to routinely clean
them. We have a number of wastewater
facilities running the tubing for
over 5 years. I would recommend
they replace the tubing every 3
years however to maintain energy
efficiencies. The maintenance for
our aero-tube system is simple
especially when you use it
continuously 24 hours a day!
Under proper operating conditions
the tubing should not become
blocked. It may clog if it is
placed directly on the pond bottom,
because it is designed to be
suspended eight to ten inches off
the bottom. Aero-Tube™ aeration
tubing works best when run
continuously but it can also be used
intermittently as long as it is run
regularly to clear out any potential
contamination. Cleaning the tubing
is very simple, 1) Wear a pair of
gloves and wipe/rub vigorously, 2)
Increase your airflow for a short
period of time and that will blow
off the debris.
We HIGHLY recommend when removing
the tubing when not in use especial
in muddy water. This tubing is more
efficient ran continuously. Never
leave the tubing out in the sun for
long periods of time.
|
|
Bubble size |
What is the Bubble size and teh no.
of Pores per meter of Length? |
The average bubble is 1 to 3 mm,
changing with airflow per meter
tube. There are an incredibly high
number of pores per meter |
|
Blower |
is blower very important in
aero-tube system? |
Not all blowers give the same CFM
per KW and therefore it is VERY
important that you choose the
highest output of air per KW. For
example, we have worked with Fuji
and Allstar blowers and although
they are both 1 horsepower blowers,
the Fuji only gives 54 CFM and the
All Star 75. In this situation, you
will have the same energy
consumption but the SAE using these
two blowers will be completely
different because of the different
flows. This is very important to
understand.
|
|
SAE |
Does the water depth affected SAE |
Depth does affect SAE because the
deeper the water, the more energy
needed to push the air to the bottom
(more head pressure). HOWEVER,
because we have such small bubbles,
the deeper they are, the more time
they have in the water column when
they rise to transfer oxygen. This
is why it isn’t such a major
difference when comparing .7 m with
1.5 meters. If you go much deeper
though to say 2, 3 or 4 meters, the
KW needed to push the air becomes
greater. |
|
water depth |
for our Aero-Tube do we have a best
result for the grids place depth in
aqua pond considering the SAE,(
blower compressor, cost, water
mixing….)? |
The key thing is you need 0.4 CFM
per foot of tubing AT THE DEPTH THE
CUSTOMER IS WORKING. So we can’t
just recommend 1 – 1.1 kw blower for
3 grids in every situation. If a
pond is 1 meter this may work but at
2 meters this will not be enough
air. You need to have the
efficiency curve and check this
before recommending. |
|
water depth |
our grid could mixing the water well
just 0.8 M below the surface of the
water in water depth ranging from
1.3-2.5M, right? |
The grid moves so much water, it
will mix the pond even if it is only
.8 meters below the surface. This
will not be an issue. He can also
place them 20-30 cm from bottom but
you need to make sure he has the
correct flow (m3 air) per grid at
this depth. If it is too low flow
(because of the water column
pressure), it will actually work
worse |
|
water depth |
Do we have a suggestion for depth of
placing grids? |
There is no standard rule, the
customer can use the grids at any
depth. The only issue is they will
need more grids or less grids
depending on the flow. I believe
the All Star works perfectly with 3
grids (0.4 CFM per foot or 26.4 cfm
per grid) at approximately 1.0
meters depth (40 inches). If we go
less deep, they will have a slightly
higher flow rate than 0.4. This is
fine, it will simply mix better. If
they go deeper than 1.0 meter they
will have slightly less flow which
will increase slightly their oxygen
transfer but drop the amount of
water they move. |
|
hose lenghth |
If the hose is two long between the
grids, could the airflow compressor
decrease quickly? |
It depends on the material in the
tubing. If he is using HDPE (High
density poly ethylene) there is very
little loss over 60 meters. If the
tubing is PVC, he will have greater
losses. If it is HDPE 60 meters
will be fine. |
|
hose and air valve |
the blower’s airflow becomes less
and less along the long length hose
accordingly different grid faces
different compressor. The result is
the airflow is different between the
three girds if we do not control the
valve to each grid, so how to do? |
This is correct. What I would
suggest is that they use T Valves at
the point they connect the different
grids. This way they can reduce the
flow to the first grid and increase
to the last one in case there is
different flows. |
|
hose |
Can we give a standard suggestion
for farmers because they use
different hose( length and diameter)
to connect the grids. |
It is actually more about the
material they are using for their
hose. Different material has
different levels of head loss JUST
from the tubing, not considering our
grids. Yeah a standard suggestion is
ok! |
|
shrimp |
how many kg shrimp can one grid
service |
We need 1 Grid (20 meters) per 700
kg of shrimp depending on the
density, etc.. Therefore, for 7 MT
we need 10 grids or 200 meters total
tubing |
|
SAE |
what’s grid’s SAE? |
Looks like in Fresh we are 1.2 kg
per hour transferred in freshwater
and 3.0 kg per hour in 35 ppt salt
water. This is PER GRID. |
|
Hatchery |
How to use tube in Hatchery? |
Most hatchery people I have showed
IMMEDIATELY recognize the advantage,
just by looking at that video
showing the air output from our
tubing and the PVC in the same
tank. They can immediately see the
benefit.
Plus remember, because drilled PVC
is inefficient, they can reduce the
number of blowers they are using or
increase the number of tanks per
blower by switching. This saves
money in electricity every day,
week, month, year. We had a
customer in Mexico using 1 - 4.5 HP
blower (3.5 KW) per 2 – 24 MT tanks
to supply air. With the Aero-Tube
tubing, he is now running the same
blower but for 4 tanks instead of
2. Imagine the savings in that.
These are the type of arguments you
need to use when the farmer or
hatchery says our tubing is too
expensive or that it is more
expensive than competition tubing.
Over time, we are actually the
cheapest option when you take in all
costs.
What I would say is that of course
every hatchery has a different idea
of the best way to use the tubing.
Some used a single line run down the
center of the tank, some used 2
lines down the length of the tank in
order to move/mix the water better.
And the largest user just uses 3 – 2
meter sections per tanks because he
already has a number of air stones
in his tanks and does not want to
replace them until they break.
Now, the optimal flow really
depends on what the hatchery wants
to do. At 0.4 CFM per foot you will
get very good oxygen transfer but
not as much mixing in a tank. I
think perhaps for a hatchery tank it
would be a good idea to increase
this to 0.5 or even 0.6 CFM per foot
in order to keep everything in
suspension in the tank. 0.4 CFM is
the optimal for transferring oxygen
with small bubbles, if mixing the
water is more important you can
increase this as high as 0.8 CFM per
foot and still get good results but
the O2 transfer efficiency will drop
some.
With the tubing, there are many
different ways to use the product
and get good results. I really
depends on what the hatchery is
doing now and how we can adapt our
tubing to match their system. For
example. If a customer has a 6
meter long tank with drilled PVC run
down the middle of the tank (6
meters) in one line, we can easier
recommended one line of Aero-Tube of
the same length and they could
reduce the number of blowers they
need to use per tank (PVC drilled
takes much higher pressure to
operate).
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electricity |
If no electricity in sitel, how to
use aero-tube system? |
If no electricity, you could use a
diesel power blower instead of
electric. |
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use |
how many aero-tube or grid needed
for fish or shrimp? |
Could tell me what is the species of
the fish raise in the pond, and the
harvest density? This is the most
important data to calculate the
aero-tube or gird needed for your
pond.
Our one grid with 44m3/hr airflow
could ensure 700kg shrimp’s oxygen
need. And in China we usually use
two to three grids in one acre fish
pond with total 6-8 tons carp
product.
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Mix water ability |
We use paddle wheel aerators not
only for oxygen but water flow. The
paddlewheels are placed to create a
circular water flow so that the
waste is collected in the middle
which makes it easy to remove after
harvest.
With your aero tube airlift, is it
still possible for me to control the
flow of the water?
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Recently, we tested a 1 hp
paddlewheel against a 1 hp Aero-Tube
air lift specifically looking at the
mixing and circulation in the pond.
What we found was that the results
were identical. I have attached
several pictures showing the
comparison. The total test took 35
minutes from the time the dye was
released in the pond. Each pond was
exactly the same size 0.4
Ha. There was one very interesting
note however. Both ponds used
exactly the same amount of dye and
it was applied in exactly the same
spot in the pond. In the final
picture you will notice that the
color in the air lift pond after 35
minutes is much darker. This is
because the dye in the paddlewheel
pond had begun settling out of the
paddlewheel pond. We believe this
is because the paddlewheel is mostly
mixing the top portion of the pond
where the air lift is moving the
complete water column and keeping
the dye in suspension.
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Floating |
How much weigth require to pull the
hose down?
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In working condition one meter
tubing’s floating is less than 500g
and for one grid the floating is a
less 25kg.
You could use stainless steel or
something else such brick to make it
sink.
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Using |
How much tubing I need ? |
Really it depends on the stock
density, harvest density, aqua
species..etc. We have two basical
method for how many tubing a pond
needed: 1- How many paddlewheels you
need for your pond and what's the
total power? If we need the
traditional aerators configration we
can say that you only need one third
of Aero-Tube configration based on
Power with tubing's working water
depth 1.0-1.5 meters. 2- We have
detail data for vannamei shirmp
culture. That is with air release
depth 1-1.5m and airflow 2.2m3/m.hr
one meter aeration tubing can
support 25-35kg shrimp in aqua pond. |
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blower |
5. What size of blower to use ? |
depends on the system pressue and
total airflow needed.
a) System pressure=tubing’s
operation pressure( 7kpa)+water
depth( 10cm water depth=1kpa so
1meter water depth=10kpa)+pressure
loss at connecting hose between
tubing and blower( usually if you
use >50mm hose as main hose and
>25.4mm hose as lateral hose and the
total lengh is less than 200m the
pressure at hose will be less than
5kpa) with these data you can select
the correct blower which shoud have
a maximum operation pressure than
the above system pressure.
b) Airflow: It is easy to calculate:
when you know your harvest density
you will know the tuibng quanity you
need and then the airflow you need.
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