Supratec OXYFLEX MF1100 Installation, Operating And Maintenance Instructions

von-Drais-Straße 7 • D-55469 Simmern / Hunsrück • Tel: [phone] • Fax: -01 • www.oxyflex.de • [e-mail] (Status Dec. 2018)

OXYFLEX®- MF1100

Membrane Plate Diffuser

for fine bubble and coarse bubble diffusion of liquids

INSTALLATION, OPERATING and MAINTENANCE

INSTRUCTIONS

The OXYFLEX®- MF1100 membrane plate diffuser consists of a flat, heavily ribbed base plate with air-sockets. A
two-piece frame secures the membrane to the base plate. The base plate and the frame are made from fibre glass­reinforced polypropylene, and the membrane is available in EPDM or TPU.

von-Drais-Straße 7 • D-55469 Simmern / Hunsrück • Tel: [phone] • Fax: -01 • www.oxyflex.de • [e-mail] (Status Dec. 2018)

INSTALLATION INSTRUCTIONS

Dimensions

Free membrane area: 0.2 m²

Materials:
Membrane: EPDM (ethylene propylene diene rubber)

TPU (thermoplastic polyurethane)
Base plate: Polypropylene (PP-GF)
Frame: Polypropylene (PP-GF)
Gaskets: EPDM

The distance between the diffusers on the distribution pipe (connection hole axis) should be at least 280 mm and
must not exceed 1,000 mm (differences possible on request).

In the vicinity of the mixer, optional side
brackets provide additional stability and make
area-wide coverage possible in this case as
well (independently of the type of installation
on round or square distribution pipes).

Storage
Store the diffusers in their packaging in a dry

and ventilated room.
DIN 7716 provisions must be observed.

Preparation
Prior to installing the OXYFLEX®- MF1100 membrane plate diffuser it must be ensured that the pipelines are clean.

All drilling chippings, dirt, etc. must be removed, otherwise they will be carried into the diffuser when the fan is
started up and could cause significant impairment or damage.

von-Drais-Straße 7 • D-55469 Simmern / Hunsrück • Tel: [phone] • Fax: -01 • www.oxyflex.de • [e-mail] (Status Dec. 2018)

Levelling
The OXYFLEX®- MF1100 membrane plate diffuser is mounted onto distribution pipes (round or square pipe

depending on version). The distribution pipes must be levelled to a maximum of ± 10 mm.

For installation on round pipes with Supratec supporters,
the pipe clamps must be tightened with torque of 10 Nm
(M10); 20 Nm (M12). The surface pressure that this
produces ensures that installation is distortion-free.
Threads have to be lubricated before screwing the nuts to
avoid seizing.

Type 'B': Installation on square pipe

The OXYFLEX®- MF1100 type 'B' membrane plate diffuser is mounted on a square pipe (width at least 60 mm)
with 4 threaded bolts M6 x 35 mm.

An EPDM gasket is inserted between the diffuser and the distribution pipe. The surfaces must be clean and
straight. Gasket must sit clean and undamaged between the diffuser and the pipe.

The distance between the bolts is 227 x 30 mm (see sketch). We would be pleased to provide you with an
appropriate welding template. The air-socket Ø = 29 mm is inserted from above into the bore hole Ø = 30 mm of
the square pipe and bolted in place using the threaded bolt that is now protruding from the side fastening lug of the
diffuser frame with washers and self-locking nuts M6 (4 Nm). The threaded bolts must be lubricated beforehand to
avoid seizing.

Always make sure that the diffuser is firmly and horizontally seated.

Washer 6,4 DIN 9021

Self-locking nut M6DIN 985

Gasket Ø 38/30 x 10 (EPDM)

threaded bolt M6x 35

30 mm

von-Drais-Straße 7 • D-55469 Simmern / Hunsrück • Tel: [phone] • Fax: -01 • www.oxyflex.de • [e-mail] (Status Dec. 2018)

Type 'AS': Installation on round pipe

The OXYFLEX®- MF1100 type 'AS' membrane plate diffuser is attached to a round pipe made from stainless steel
or plastic using a clamp saddle.

Bore holes with a diameter of Ø 25 mm are drilled in a central position on top of the round pipe. The top part of the
clamp saddle that is welded to the OXYFLEX®- MF1100 membrane plate diffuser has a supply air pipe connection.
This acts as an installation aid and is inserted into the hole of the round pipe from above.

An O-ring made from EPDM is inserted between the upper part of the clamp saddle and the distribution pipe. The
gasket between the diffuser and the pipe must be clean and undamaged.

The hinge of the lower part of the clamp saddle is hooked into the upper part. Now the clamp saddle is closed and
screwed in place using an M8 x 65 mm hexagon screw, a washer and a self-locking nut (7 Nm). The thread of the
hexagon screws have to be lubricated beforehand to avoid seizing.

Always make sure that the diffuser is firmly and horizontally assembled.

Possible pipe dimensions:

For stainless steel pipes:
DN 65 (75 mm) / DN 80 (88.9 mm))

For plastic pipes (outside Ø):
75 mm / 90 mm / 110 mm

(Further sizes are available on request.)

von-Drais-Straße 7 • D-55469 Simmern / Hunsrück • Tel: [phone] • Fax: -01 • www.oxyflex.de • [e-mail] (Status Dec. 2018)

Type "SA": Fitting to square pipes with holes at side

The OXYFLEX®- MF1100 type 'SA' membrane plate diffuser is secured using side adapters to square pipes with
two bore holes in the side.

A flat gasket made from EPDM is inserted between the square pipe and the side adapter or the square pipe and
the counter piece. The surfaces must be clean and straight; the gaskets must sit clean and undamaged between
the adapter and the pipe.

The side adapter is inserted into the 38 to 45 mm diameter bore holes at the sides and screwed in place with the
counter piece at the opposite side using an M10 hexagonal through-screw (16 Nm). The thread of the hexagon
screws have to be lubricated beforehand to avoid seizing.

An O-ring made from EPDM is inserted between the side adapter and the connecting thread of the diffuser. The
gasket between the diffuser and the adapter must be clean and undamaged.

The OXYFLEX®- MF1100 type 'SA' membrane plate diffuser is screwed into the 2" thread of the side adapter in a
secure and stable way using the air-socket. In order to secure the installation position firmly, 2 additional non-twist
angles are screwed into the lugs of the frame (M6 x 35 mm)

Always make sure that the diffuser is firmly and horizontally seated.

Possible square pipe dimensions:

Height: 80 mm, 100 mm, 120 mm

Width: variable

(Further sizes are available on request.)

von-Drais-Straße 7 • D-55469 Simmern / Hunsrück • Tel: [phone] • Fax: -01 • www.oxyflex.de • [e-mail] (Status Dec. 2018)

OPERATING INSTRUCTIONS

Functional check and leakage check

After the OXYFLEX®- MF1100 membrane plate diffuser has been installed, a functional and leakage check must
be performed. In order to do this, fill the tank up to a level of approx. 10 cm above the top edge of the diffuser with
clean water. It is recommended to operate with minimum air amount (see tables on page 8), before the water level
reached the aeration grid, in order to avoid water ingress by some bad sealing.

To check the function visually, the diffusers are loaded with the specified amount of air in accordance with the
diffuser version (see tables on page 8).

After ensuring that all diffusers are functional, the air quantity is reduced in accordance with the diffuser version
(see tables on page 8) in order to make it easier to perform the leakage check. Rising large bubbles indicate leaks
(e.g. due to gaskets that have been dislodged) those must be remedied.

The successfully performed functional and leakage check must be documented and the water level increased to at
least 100 cm above the top edge of the diffuser as quickly as possible.

Diffuser run-in
Different procedures are recommended depending on the membrane material and the diffuser version:

• EPDM membranes:

The compressed air must not be turned off between the function and leak-tightness check and the run-in of
the diffuser. OXYFLEX®- MF1100 membrane plate diffusers with EPDM membranes must be operated
continuously for at least 60 hours with the specified specific load (see run-in of diffusers in table 1 on page 8).

• TPU membranes:

OXYFLEX®- MF1100 membrane plate diffusers with TPU membranes do not have to be run in for normal
operation. However, a bubble pattern test or an oxygen transfer test can be carried out no sooner than 24
hours after start-up (for specific load see table 2 on page 8).

Deviating procedures are possible in consultation with Supratec.

Bubble pattern
The bubble pattern should be assessed no sooner than when the above-described run-in of the diffusers has been

completed. For this purpose the diffusers are operated from the maximum down to the minimum specific load.
The evenness of the aeration (bubble pattern test) should be checked when the tank is filled to a level of approx.

100 cm of water above the diffuser top edge.
Checking the evenness of the aeration is only possible at a water temperature of above 10°C.

Oxygen transfer test
Prior to carrying out an oxygen transfer test as proof of the efficiency of the OXYFLEX®- MF1100 membrane plate

diffuser, the above-mentioned steps must have been completed.
The oxygen transfer test can be carried out in accordance with the accepted regulations (e.g. DIN EN 12255-15

: 2003 or DWA-M 209) using the fresh water or waste water method. Specified warranty values must be rigorously
adhered to. A calibrated and exact measurement of the air volume is required.

Commissioning

If commissioning is delayed and/or system is decommissioned later on, it must be ensured that the diffusers are

sufficiently covered by water (at least 100 cm) so that the OXYFLEX®- MF1100 membrane plate diffuser is
protected against strong sun, frost and mechanical damage caused by falling objects, for example.

After successful commissioning, a reference pressure loss measurement enables the evaluation of actual state of
aeration system in operation.

von-Drais-Straße 7 • D-55469 Simmern / Hunsrück • Tel: [phone] • Fax: -01 • www.oxyflex.de • [e-mail] (Status Dec. 2018)

MAINTENANCE INSTRUCTIONS

The OXYFLEX®- MF1100 membrane plate diffuser is a low-maintenance system and is partially self-cleaning due
to the different specific air loads during the normal operating cycle. Especially with an intermittent operation mode,
the normal operation cycle can be used for parallel maintenance as described below. Depending on the operating
conditions we recommend an appropriate maintenance cycle. This maintenance cycle is also used for removing
deposits after longer periods of inactivity and long-term operation with low specific loads.

Maintenance cycle
Any deposits are removed by short-term load-dependent changes of the membrane extension. This also prevents

any accumulation of biological growth.

• EPDM membranes:

We recommend daily and no less than weekly maintenance loading in accordance with the diffuser version
(see table 1 on page 8) of approx. 15-30 minutes. Using intermittent operation, the first 10-15 minutes of each
aeration cycle are used with the higher maintenance air flow in advance of standard operation.

• TPU membranes:

We recommend a brief pressure relief on minimum daily basis (system pressure reduction of approx.
100mbar) for the duration of minimum 5 minutes and a quick restart to the maintenance loading in accordance
with the diffuser version (see table 2 on page 8) for the duration of approx. 5-10 minutes. Using intermittent
operation, pressure is to be briefly relieved at the end of each aeration cycle, next aeration cycle is to be
started for the first 5-10 minutes with the higher maintenance air flow (see table 2 on page 8) in advance of
standard operation.

Deviating procedures are possible in consultation with Supratec.

Monitoring
The bubble pattern and the pressure loss should be checked and documented at regular intervals under similar

operating conditions (such as water level and air quantity). The pressure loss development in the load-dependent,
seasonal comparison makes it possible to evaluate the condition of the container objectively.

In the event of significant changes of the bubble pattern (e.g. partial massive large bubbles instead of homogenous
fine bubble pattern) and/or increase of pressure loss of the system (for more than 40 hPa compared to
commissioning), Supratec should be consulted immediately. Particularly in the case of systems that are operated
intermittently, there is a risk that damaged diffusers can allow the ingress of live sludge into the entire pipework
system. This will adversely affect the function and service life of all diffusers.

Cleaning
The condition of the diffusers must be checked whenever the tank is emptied. Particular attention must be paid to

soiling (deposits, sludge, coverings etc.), which can usually be easily removed from the membranes. Depending on
the type and composition of the soiling, one of the following methods or a combination of several methods might be
required. Testing for compatibility and successful results must always be carried out first on individual membranes
(particularly with alkalis and acids). We recommend:

• Manually: Cleaning with water and a soft brush is often sufficient for removal of existing deposits

• Alkaline solutions: Diluted alkaline cleaning agents can usually be used to help with manual cleaning.

• Acids: Recognizing pressure increase, dosing of diluded acids in to the compressed air can be

required in order to clean the membranes (compare below information)

Acid dosing

In systems in which limescale deposits are to be expected, we recommend that these systems are cleaned

with diluted acid (≤ 85% formic acid for EPDM membranes or ≤ 30% acetic acid for TPU membranes) at

regular intervals. If necessary, diluted acid is metered into the compressed air in order to minimise the

von-Drais-Straße 7 • D-55469 Simmern / Hunsrück • Tel: [phone] • Fax: -01 • www.oxyflex.de • [e-mail] (Status Dec. 2018)

pressure loss of the membrane and increase the service life of the diffuser. For this purpose, we offer a mobile
dosing station for perfectly metered cleaning.

Please contact Supratec for further information about acid dosing.

Repair measures

Our more than 30 years of experience have shown that the OXYFLEX®- MF1100 membrane plate diffuser is an
extremely robust and reliable diffuser. If a diffuser element is damaged nevertheless, a diver can be deployed to
remedy the problem without having to empty the tank. The diver can remove the damaged diffuser underwater and
close off the relevant bore hole. Depending on the diffuser system that is installed, several bore holes can often be
closed off without having a major effect on oxygen transfer. The replacement of individual diffusers on an existing
grating is not recommended, since new membranes differ considerably from older membranes with regard to
pressure loss. We would be pleased to provide advice if necessary.

Table 1: Specific loads [

/hm

3
N

per diffuser] for the OXYFLEX®- MF1100 membrane plate diffuser

with EPDM membrane

Diffuser version Premium

Max

Efficient

High

Efficient

Efficient

High

Airflow

Max

Airflow

Functional check 4 6 10 12 20 30

Diffuser run-in 4 6 10 12 20 30

Bubble pattern
(starting with higher specific load)

0,5 - 4 0,5 - 6 1 - 10 2 - 12 3 - 20 10 - 30

Minimum specific load

/

leakage

check

0,5 0,5 1 2 3 10

Nominal operating range 1 - 3 2 - 4 4 - 8 5 - 11 8 - 14 25 - 35

Maximum continuous load 3,5 5 9 12 16 40

Maximum short

-

term specific load /

maintenance load

4,5 7 10 14 20 45

Table 2: Specific loads [

/hm

3
N

per diffuser] for the OXYFLEX®- MF1100 membrane plate diffuser

with TPU membrane

Diffuser version High Performance

Functional check 6

Diffuser run

-

in prior to the oxygen transfer test (at

least 24 hrs.)

4

Bubble pattern

(starting with higher specific load)

1-4

Minimum specific load / leakage check 0,5

Nominal operating range 1-4

Maximum continuous load / maintenance load 10

We reserve the right to make technical alterations.

For current version please check our website www.oxyflex.de