Water Management Systems
Vacuum Toilet Assembly
The Vacuum Toilet Assembly is a complete, self contained, freestanding unit ready to be bolted to the floor of the lavatory housing. It is the interface for the user and receives the waste matter.
On request the toilet assembly carries out a flush sequence opening a path to enable the cabin-to-waste tank differential pressure to transport the waste matter via the tubing system to the Waste Tanks.
The toilet assembly rinses itself by utilizing clear water (in most cases for weight saving purposes only 0,1 liters per flush), obtained from the pressurized potable water system.
Communication with the aircraft systems is realized by a CAN-Bus interface.
The Waste Tank Module stores the waste received from the tubing during the entire flight for discharge on the ground. It is equipped with level measurement.
A key design task is to separate the high-speed incoming waste matter in order to avoid impacting the tank structure and to safely avoid waste matter going overboard via the tank ventilation channel.
In normal operation the tank is loaded by external overpressure and shall hence be stiff enough to avoid collapsing.
For a weight-optimized design this is in most cases achieved by a proper carbon fiber composite design.
Diehl Aviation's Vacuum Generators are electric motor powered single-stage centrifugal compressors utilized to generate the required differential pressure for the waste system while the aircraft is flying in low altitudes or being on the ground. Hence, these generators are optimized for non-continuous operation and very fast acceleration of the rotational speed. The electronic controller enables the utilization in AC/DC networks with variable frequency. A specific software minimizes the noise levels in the different working regimes, optimizes the throughput performance, and minimizes the electric power demand in operation. A CAN-bus interface allows for the data communication with the aircraft on-board network.
Potable Water Pump
The Potable Water Pump pressurizes the potable water system either with or without support by the engine bleed air system on a constant pressure level. This ducted impeller centrifugal pump is powered by an electric motor and is in most cases designed for continuous operation. An embedded pressure sensor is measuringthe existing pressure and controlling the pump’s variable revolution speed in order to reach and keep the desired pressure level. A heating system saves the pump from freezing while being non-operative.
Water Treatment Module
Diehl Aviation provided the world’s airliners’ first airborne Water Treatment Module based on an UV disinfection system. UV light is well suited for fighting detrimental microorganisms in a effective and for human bodies harmless way. Neither the taste, smell, nor the color of the water is affected nor are there any unwanted byproducts. Our water treatment modules enable a large variety of throughput volumes via utilization of two UV-sources.
Ice Protection Control Unit
The Ice Protection Control Unit [IPCU] controls auxiliary heating devices for freeze protection of the water/waste system. It monitors, protects, and controls the heating devices placed on equipments in cold zones of the aircraft. The IPCU includes power electronics for switching the heating devices and a microprocessor board for bus communication to the aircraft maintenance system. The microprocessor board also includes various control modes and built-in test functions. In addition to state-of-the-art protection functions (over-current, over-temperatures ..), the IPCU uses an “arc fault detection sensor (AFDS)” to detect arcing in downstream wiring and heaters for fire protection purposes.
Potable Water Tank
The Potable Water Tank Module is filled during ground-service and stores the water during the entire flight for the corresponding supply to the consumers. A level measurement system is included. Based on the requirements for the installation envelope the tanks may be round vessels for structural weight optimization or have fuselage-conform shapes.
Depending on the selected system architecture the tank may be pressurized or have ambient pressure. For a weight-optimized design carbon fiber composite is used in most cases.