GVA systems technologyMeasuring installation for differential pressure measurement (DDM) on all air diffusers

Near the activation basin the pressure loss at the membrane is determined by differential measurement. It is possible to design the measuring head to be fixed or maneuverable so that measurements can be taken in several places, e. g. in change areas. For this purpose, the system pressure is measured and used as the reference value, and the differential pressure is determined using a water-bubble aeration tube. This differential pressure value represents the pressure loss of the aeration components. Since the pressure loss depends on the air throughput of each aeration component, a predefined operation setting must be specified. The system pressure is moni¬tored based on a pressure measure¬ment from a pressure gauge with a measuring range of 0–1.0 bar that is normally located near the compressors, but unfavorable pressure losses on the aeration components cannot be detected.

For this reason, GVA offers an optional flow measurement (DFM), when the measuring installation and GVA test lance are used together so that every air admission rate desired can be set. This is absolutely necessary if there is no other way to set a specific air admission rate through the compressors. The flow rate can be measured using a calibrated Nm3/h flow meter. The air quantity can be adjusted using a valve whose setting range depends on the test lance used. If there is no flow measurement for the aeration device, then this measurement can also be used for control operations or to determine the total air quantity.

Flow chart of the GVA measuring installation