Wilo Wilo-Sevio AIR, Инструкция по установке и эксплуатации

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70 WILO SE 11/2012 Ed.03 DIN A5
English MAINTENANCE
Deposits on the aerator membranes reduce the air inclusion into the liquid and increase
the pressure in the aerator system. This reduces the efficiency of the system. This
becomes visible due to a changed appearance of the bubbles on the surface of the
liquid. In this case, the maintenance measure “Cleaning the membrane surface” must be
carried out.
If the aerator system is not tight or if a membrane cracks, the pressure drops in the
aerator system. This leads to uncontrolled air inclusion and causes the efficiency of the
aeration to drop. This also becomes visible on the surface of the liquid, where large air
bubbles will be escaping. In this case, the plant needs to be taken out of operation and a
function test with clear water must be conducted in order to find the leak.
Regular checks can therefore prevent greater damage from occurring later and reduce
the risk of a total failure. For monitoring on a regular basis, we recommend remote mon
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itoring of the air inclusion. Please contact Wilo customer service about this.
8.2. maintenance tasks
8.2.1. Function run
To prevent damage to the membrane, a function run lasting 10 minutes must be con -
ducted. Here it must be ensured that a minimum water level >1 m exists in the operating
area. The air inclusion must be between 1.5 Nm³/h and 6 Nm³/h.
8.2.2. Drainage of the aerator system
During the function run, open the valve of the drainage line. Supplying air into the
aeration system causes any water/condensate that is present to be channeled through
the drainage line.
8.2.3. Cleaning the membrane surface
During operation, the membrane surface can be clogged by deposits. This leads to
reduced air inclusions into the fluid and decreases the efficiency of the aeration system.
To counteract this, the membrane must be blown off in brief intervals under peak load
in accordance with the maintenance intervals.
1. Increase the pressure in the system to the max. permitted value of 7.5 Nm³/h for five
minutes.
2. Switch off the aeration for two minutes.
3. Repeat these steps 3 to 4 times.
The max. permitted value for pressurization of 7.5 Nm³/h may not be exceeded.
Since this maintenance measure makes a major contribution to the functional safety
and efficiency of the system, we recommend that the maintenance interval be carried
out automatically. This can be accomplished using a control station. Contact the manu
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facturer of the control station in this regard.