Tsurumi Submersible Aeration (1846 Kb) - Ferret

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▼ 7–2-2. Equipment necessary for this Operation· The blower must be operated with a VFD (Never use direct-on-line starting to start the blower.). Operationwith a VFD will be effective in energy saving.· One (1) blower must be engaged to one (1) aerator only. This is because, the air is transferred to the deeperarea of the tank by utilizing both the outlet pressure of the blower and the suction force of the aerator, and itis required to keep the balance between the two equipments. If the balance is disrupted, the aerator may idle(impeller runs in air) or may stop its operation by due to tripping of the motor protection device caused by anoverloading reason. As a result of these conditions, the blower gets into the “closed-valve” operation, whichcan cause the danger of a breakdown of the blower by the reason of overload or abnormal pressure.· Be sure to provide a non-return valve in the blower outlet piping. This is to prevent the treating liquid fromflowing back to the blower when the blower stops. Back-flow of the treating liquid pressurizes the air in thepiping, and this may cause the danger of a breakdown of the blower.· Provide a pressure gauge, which indicates the outlet pressure of the blower. This is required for operationadjustments.· When there is a need for the correct adjustment of air flow rate, provide a flow meter.· For other precautions, follow the instructions specified in each design manual.Blower HouseBlower(with VFD)Pressure GaugeNon-return ValveAir-inlet PipeW.LPressure depth coveredby the blowerInstallationWater Depth hSelf-aspiration water depth d bythe submersible aerator (within themaximum installation water depthof each aerator)<strong>Submersible</strong> Aerator12Australian Pump Industries (02) 8865 3500
▼ 7-2-3. Operation· Operation of the submersible aerator and the blower shall be controlled in such a manner that both equipmentbe started or stopped simultaneously.· Regulate the acceleration time (VFD) to approximately 10 seconds, and secure the stable starts of theseequipments. In case that the acceleration time is longer than this, the motor protection device of the aeratormay trip to stall the aerator by due to overload, and as a result the blower may have the danger of breakdowndue to overload or an abnormal pressure. In addition, the deceleration time (VFD) shall be regulated to theregion between 15 to 20 seconds so that the non-return valve may not suffer an impact.▼ 7-2-4. Adjusting Procedure for Air Flow Rate (e.g. 200V, 50Hz)Step 1. Prepare a clamp meter to measure the running current of the submersible aerator.Step 2. Regulate the rotating speed of the blower with VFD, according to the “Initially Targeted OperatingPoint of Blower” in the table of p.15 7-2-7.✳ Do not carry out this adjusting work by solely operating the blower. In case that the aerator is not operatingtogether, there may be the danger of breakdown of the blower by due to overload or abnormal pressure asthe blower gets into the “closed-valve” condition.Step 3. Start the submersible aerator and the blower simultaneously.Step 4. Confirm that the running current of the submersible aerator is within the limit of “Operating Range ofAerator on Running Current” described in the table of p.15 7-2-7. If not, rotating speed of the blower sothat the running current of the submersible aerator may fall within the operating range.✳ Method to decrease the running current of submersible aerator; Increase the rotating speed of the blower.By this, the self-aspiration water depth d of the submersible aerator becomes shallower and the runningcurrent will be decreased.✳ Method to increase the running current of submersible aerator; Decrease the rotating speed of the blower.By this, the self-aspiration water depth d of the submersible aerator becomes deeper and the runningcurrent will be increased.✳ If the running current of the aerator plunges much lower than the “Operating Range of Aerator on RunningCurrent”, it shows a symptom that the balance between the outlet pressure of the blower and the suctionforce of the aerator is disrupted, and that the aerator is not generating any suction force because it is idling.In this case, stop both of the blower and aerator immediately. If this condition continues, there will be thedanger of breakdown of the blower by due to overload or an abnormal pressure as the blower gets into the“closed-valve” operation.Step 5. Adjust the rotating speed of the blower with VFD in such a manner that the blower may discharge thetargeted air flow rate at its required pressure in a graph of 7-2-11. “Discharge Pressure of Blower vs. AirFlow Rate Curve (combination with blower – 50Hz)” on page 18.✳ Note that, depending on the operating condition, the blower could discharge the targeted air flow rate at apressure point lower than indicated in a graph of p.18 7-2-11. In this case, adjust the rotating speed of theblower assuming that it discharges maximum air flow rate on its graph at the point of minimum (running)current in the “Operating Range of Aerator on Running Current” in the table of p.15 7-2-7 and that itdischarges minimum air flow rate on its graph at the point of maximum (running) current in the range.13Australian Pump Industries (02) 8865 3500
Page 7 and 8: ■ 4-4. Notes to the Case that Two
Page 9 and 10: 6. Oxygen Transfer RateThe oxygen t
Page 11 and 12: ■ 6-3. Oxygen Transfer Rate vs. W
Page 13: ■ 7-2. Operation in combination w
Page 17 and 18: ▼ 7-2-7. Initially Targeted Opera
Page 20 and 21: ▼ 7-2-11. Discharge Pressure of B
Page 22 and 23: 8. About NoiseSuction noise will be
Page 24: Equipment Selection GuideSewage/was

Tsurumi Submersible Aeration (1846 Kb) - Ferret

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