AquaFlex ADD300-12” User manual

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ADD300-12”
FINE BUBBLE DISC DIFFUSER
TECHNICAL MANUAL

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CONTENTS
1) INTRODUCTION 3
1.1) Performance of the Diffused Aeration System 3
1.2)Receiving the Equipment 3
1.3)Storage 3
1.4)Lifetime of the Disc Diffusers 3
2) INSTALLATION 4
2.1) Installation of Disc Diffusers 5
3) STARTUP 5
3.1) Startup Instructions 5
4) OPERATION 5
4.1) Operation of the Disc Diffusers 5
5) TROUBLESHOOTING 6
6) MAINTENANACE & CLEANING 6
6.1) Maintenance of Aeration System 6
6.2) Replacing Disc Diffuser Equipment 6
6.3) Cleaning Disc Diffusers 7
6.3.1) Bio fouling 7
6.3.2) Settling of Bio Slime and Solid Matter 7
6.3.3) Scale Formation 7
6.3.4) Leakage of Sewage 7
6.3.5) Water Flush Cleaning 7
6.3.6) Air Purge Cleaning 7
7) WARRANTY 8
7.1) Limitation of Warranty 8
7.2) Warranty Repair 8
7.3) Repair after Warranty Expiration 8
7.4) Limitation of Liability 8

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1.INTRODUCTION
Activated sludge process is the main stage of modern wastewater treatment technology. Key component of the
activated sludge process - Aeration system is serving for two purposes: to satisfy oxygen demand and to provide sufficient
mixing turbulence to keep solids in suspension. Oxygen must be provided in biological activated sludge waste water treatment
systems to satisfy several types of demands:
Organic oxygen demand that can be further divided into oxygen required for cell synthesis and oxygen required for
endogenous respiration.
Biological oxidation of ammonia nitrogen
Oxidation of certain inorganic materials that may be present in the wastewater
The two most common aeration systems are under water and mechanical. In a subsurface system, air is introduced by
diffusers or other devices submerged in the wastewater. A mechanical system agitates the wastewater by various means (e.g.,
propellers, blades, or brushes) to introduce air from the atmosphere.
Fine pore diffusion is a subsurface form of aeration in which air is introduced in the form of very small bubbles. There has
been increased interest in fine pore diffusion of air as a competitive system due to its high oxygen transfer efficiency (OTE).
Smaller bubbles result in more bubble surface area per unit volume and greater OTE. Diffused aeration systems can be classified
into three categories:
Porous (Fine Bubble) Diffusers: Concept of the fine bubble corresponds to the size of 1-3 mm. These diffusers come in
various shapes and sizes such as discs, tubes, domes, and plates.
Nonporous (Course Bubble) Diffusers: These are in the form of perforated piping, spargers etc. The bubble size of theses
diffusers is larger than the porous diffusers (larger than 10 mm), thus lowering the OTE.
Other Diffusion Devices: These include jet aerators, aspirators, and U tubes.
Performance of the Diffused Aeration System
The performance of diffused aeration systems under normal operating conditions is directly related to the following parameters:
Wastewater characteristics
Process type and flow regime
Loading conditions
Basin geometry
Diffuser type, size, shape, density, and airflow rate
Mixed liquor dissolved oxygen control and air supply flexibility
Mechanical integrity of the system
Operator expertise
Fouling
The quality of the preventive operation and maintenance program.
Receiving the Equipment
Aquaflex or the distributor of Aquaflex sends the equipment which is bought by you and thus usage period of the
products will be started. When you acquire these goods you should firstly examine them for the damages originated from
transportation process. If you encounter to any problem please report them to our Technical Service Department or the
distributor in ten days.
Storage
Storage conditions of Aquaflex membrane diffusers have a considerable influence upon the future performance. Aquaflex
products should not be exposed to sunlight, heat, mineral oils, aromatic/aliphatic hydrocarbons, halogenated solvents, or
concentrated acids and keep away from the heavy duty workings such as welding etc. Additionally, Aquaflex membrane
diffusers should not stay in storage beyond six months.
Lifetime of the Disc Diffusers
The lifetime of diffuser equipment is a function of different factors. However it corresponds exactly to the lifetime of the
rubber membrane. Thus, it can be said that the lifetime of a diffuser was determined by the following:
Proper membrane compound selection
Quality membrane manufacturing
Air flux (airflow per square foot or square meter of membrane). Higher flux rates reduce membrane life as well as
reduce diffuser efficiency
Chemical composition of wastewater
Temperature of wastewater
Exposure to sunlight for extended periods
Proper diffuser construction to support and protect the membrane
Proper diffuser installation and maintenance

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Please discuss the given situation at your site of activated sludge process with Aquaflex or the distributor to make a
convenient choice.
2.INSTALLATION
Aquaflex diffusers are designed to offer excellent field performance and to be able to operate for prolonged periods.
However, in order to achieve such a benefit, you should abide to some our recommendations. This technical manual was
prepared to detail the suggestions and procedures.
Type
Total
Height
(mm)
Diameter
Effective/Total
(mm)
Perforated Area
(m³)
Capacity
(m³/h)
Material of
Membrane
Total
Weight
(kg)
Outlet
ADD300-12”
61
300/340
0,066
2-12
EPDM, Silicon
PTFE Coated,
PU
1,06
¾” or 1”
male

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Installation of Disc Diffusers
The Aquaflex Disc Diffuser units are furnished completely factory assembled. The only work required by the Contractor is
the installation and placement of the diffuser units on the laterals piping. Aquaflex diffusers utilize EPDM rubber membranes
specially formulated for water and wastewater aeration facilities, as the air diffusion media. Alternate membrane materials are
available for special applications. Aquaflex Technical Department recommends care in handling and storage to prevent tearing,
puncturing or fouling of the rubber membranes. If units are to be stored before installation, store in a clean, well ventilated, cool
location that avoids potential mechanical damage. Air distribution through the Aquaflex diffuser is a function of the individual
diffuser elevation. For proper system operation, Aquaflex Technical Department recommends a leveling tolerance of ±3/8" for
the diffuser unit. If the diffusers are mounted with excessive elevation tolerances, the airflow distribution in the system will be
adversely impacted.
The Aquaflex aeration system employs individual diffuser assemblies attached directly to the lateral piping. Aquaflex
normally designs the aeration piping system to provide uniform distribution of air without requiring adjustment of the
isolation/throttling valves on the laterals with the exception in situations where water level variation exists. However, these
valves are typically provided for direct control of airflow distribution on large aeration systems or for process control.
Aquaflex Technical Department has designed the Aquaflex Disc diffuser for easy on field installations. Place the threaded
end of t h e diffuser into the threaded outlet hole in the lateral pipe. Tighten the diffuser unit by hand rotating clockwise. DO
NOT OVER TIGHTEN. Over tightening the unit will cause failure to lateral piping, diffuser unit or both. When blower assemblies,
header piping, air laterals, and all units are properly installed, system is ready for startup. During all of the installation
procedure, please do not grab around the membranes.
Refer to Aquaflex Startup Instructions for details.
3.STARTUP
Startup Instructions
These instructions cover the general startup requirements for the Aquaflex diffuser system. Special startup
requirements outlined in the Engineer’s specifications, contract documents, or instructions offered by Aquaflex Technical
Department shall be supplementary to or take precedent over these general instructions.
No work may be done in the basin area after the diffusers have been placed. All works in or at the basin could cause
damage to the diffusers (e.g. painting or welding, finishing concrete works and more). Remove all tools and loose objects (even
small stones) from the basin floor before filling up the basin with water.
A trial run in the basin using clean water is to be carried out directly after installation. Performance and sealing of each
diffuser unit is tested on after the other, using a maximum 20 cm water level over the membrane disc diffusers. The presence of
leaks becomes visible after shutting off the air supply. Due to the lower pressure loss of leaks air bubbles will rise at the leaky
places, while the membranes close up.
An overview of startup procedures is related below:
Confirm that piping and diffusers are level by filling the basin with water. Adjust supports for diffusers as required
Continue filling the basin with water until the diffusers are 2, 5 cm (1”) to 5, 0 cm (2”) under water. In the event of air leaks
the diffusers are accessible
Activate the blower and introduce air to the aeration system. Check piping and diffusers for leaks, and repair if required.
For blower components refer to the blower installation and start up to ensure that all blower components are mounted
properly and ready for operation. Contractor is to confirm the cleanliness of the air piping. If existing header piping is used, the
air purge or water flush cleaning procedure is recommended prior to installation of Aquaflex units to remove any internal
debris that may have been accumulated inside the air pipeline. In order to avoid clogging from the inside the air supply pipes,
drops and header pipes must be cleaned from impurities, such as dust, sand, stones, pieces of wood, etc.
Should operation not start immediately after the test run, the water level should be increased up to 1 meter. This water level
must be maintained until the system is put into operation. Pay attention to water evaporation or ice formation. During periods
of frost, the water level must amount to at least 10% of the frost temperature (in meters). Example: the water level is 2m at
-20 °C. In order to avoid negative environmental influences on the membrane (e.g. UV-light), the period between installation
and trial run (water coverage of diffusers) should be as short as possible.