Page 79 - Commercial Catalogue 2011

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www.tropicalmarinecentre.co.uk Tel: +44 (0) 1923 284151 Commercial Catalogue 74
Air Stones and Diffusers
Aeration is used primarily for
oxygenation but may also be used for
mixing of water volumes.The efficiency
of bubble diffusers will depend largely
on two factors:-
1. The size of the bubbles that are liberated - the smaller the bubble, the higher the surface area to
volume ratio, and hence the more efficient the gas transfer.
2. The contact time that the bubble has with the water - i.e. depth of the tank.
Medium pore diffusers tend to be used most frequently. Our range of medium pore air
stones all have barb fittings for connection to air lines.
Fine air stones produce bubbles of less than 3mm. Our range of fine pore air
stones have ozone-resistant threaded fittings for connection to rigid
pipework.
The air stone bumpers fit all 1
1 / 2
" diffusers and are used to
protect the tank from the diffuser (and vice versa).
The extra fine pore, High Pressurised Bubble Diffusers are an efficient method of oxygenating water.
They require a working pressure of 1.7 bar (25psi).They should be used in conjunction with a dry gas
source from a compressor, oxygen concentrator or bulk oxygen cylinder.
Aeration Equipment
Code Grp Product
Dimensions Air supply
Connection Pore size Suggested
(")
Connection
Material
Air Flow
(
l/min)
S2
FX Medium Pore Air Stone
11/2 x 3/4
3/16" OD (4mm) barb ABS
Medium
2.8
AS3
FX Medium Pore Air Stone
2 x 1
3/16" OD (4mm) barb PE
Medium
5.6
AS4
FX Medium Pore Air Stone
11/2 x 11/2
3/16" OD (4mm) barb PE
Medium
7.0
AS8S
FX Medium Pore Air Stone
3 x 11/2
3/16" OD (4mm) barb PE
Medium
9.8
AS15L
FX Medium Pore Air Stone
6 x 11/2
3/8" OD (9mm) barb
PE
Medium
14.0
AS23L
FX Medium Pore Air Stone
9 x 11/2
3/8" OD (9mm) barb
PE
Medium
21.0
AS30L
FX Medium Pore Air Stone
12 x 11/2
3/8" OD (9mm) barb
PE
Medium
28.0
ALR150CP FX Fine Pore Air Stone
6 x 11/2
1 / 2
" NPT CPVC
CPVC
Fine
14.0
ALR230CP FX Fine Pore Air Stone
9 x 11/2
1 / 2
" NPT CPVC
CPVC
Fine
21.0
ALR300CP FX Fine Pore Air Stone
12 x 11/2
1 / 2
" NPT CPVC
CPVC
Fine
28.0
DIFFB
FX Air Stone Bumpers (for 11/2" diffusers) N/A
N/A
N/A
N/A
N/A
BD63
FX High pressure bubble diffuser*
12 x 2.3
1 / 4
" barb
SST
Extra Fine
3.60
BD64
FX High pressure bubble diffuser*
16 x 2.3
1 / 4
" barb
SST
Extra Fine
4.60
BD66
FX High pressure bubble diffuser*
24 x 2.3
1 / 4
" barb
SST
Extra Fine
7.10
* Requires minimum of 1.7 bar (25psi), and a maximum pressure of 3.5 bar (50psi).
High Pressure Bubble Diffuser
A medium sized air bubble of 3mm will rise at a rate of 1ft/sec, and hence, a bubble released from a depth of
3 ft will have a contact time of 3 seconds. Air injected at depths greater than 4 ft can lead to excess nitrogen
dissolving in the water.This can result in what is commonly known as air bubble disease.
Smaller bubbles can be created using air stones with smaller pore sizes. However, with this reduction in pore
size comes an increase in the pressure required to produce the bubbles. Smaller pore sizes also have a greater
tendency to become blocked.This can occur through dust from the air inflow, the formation of calcium
carbonate (especially in hard and salt water) and through a build up of bacterial slime on the external surface.
Technical Fact