We have already successfully completed several projects with the Austrian company EHR Fahrzeugtechnik GmbH, which made us their first point of call when they were looking for a solution for a special challenge: to install a system to treat wastewater in a vehicle that cleans the runways at an airport.

The client

The Austrian company EHR Fahrzeugtechnik GmbH specialises in cleaning vehicles for communal equipment, road construction and airports. With its years of experience in the development and production of these kinds of vehicles, EHR is one of the leaders in this market. And environmental issues are a huge concern here.

The starting point

A high level of precision in tightly allocated time frames: a membrane filtration system needed to be installed into a vehicle for cleaning the airfield and also the runways. The basic requirement is a system flow rate of up to 5000 litres an hour. This is the only way that the system can work in an efficient manner and clean the respective areas.

The challenges

This is not the first time EHR Fahrzeugtechnik GmbH has contracted us to find an individual solution for special problems. However, this time the challenge is to meet very special requirements. Developing a system for wastewater treatment for a cleaning vehicle at the airport demanded the high level of expertise of our designers and knowledge of the site itself, because the system needs to work very precisely and with a high level of availability. Tight cleaning schedules in narrow time slots need to be observed. The required compact design left very little wiggle room. Another special challenge were the exacting demands made of the technical performance, reliability and access to the individual modules.

We needed to program the system so that even staff who have received less training can carry out the cleaning cycles. This being said, only the technicians of EHR Fahrzeugtechnik GmbH were to be authorised to configure, parametrise and service the system, which meant that we needed to pay special attention to the software and control electronics that were used.

The solution

Extensive pre-testing was carried out on these special wastewater treatment modules to find the ideal combination of ceramic membranes, pore sizes and pump technology. This was the only way, despite the compact design, to minimise the performance losses of the various resistances in the cross-flow filtration and to guarantee a constantly high output. Instead of a hydraulic control system, we opted for electronically controlled pump systems for reasons of safety, reliability and space constraints.

Optimal use of space

We also met all maintenance requirements by designing a filter system which allows easy and safe mounting and removal of pumps and modules. The fold-out control cabinet makes optimum use of the space and the equipment is well protected, whilst still offering fast and direct access. As the system is controlled automatically, parameters such as the flow rate, pressure or temperature can be monitored automatically. Regular safety routines prevent clogging of the membrane pores and fully automatic cleaning cycles can be initiated to prevent damage to pumps and membranes. We opted for tried-and-tested Siemens technology for the touch control panel.

The result

Clean runways and airfields – the wastewater treatment solution we developed for EHR Fahrzeugtechnik GmbH met all requirements. The project included extensive pre-tests and intermediate tests. We also took other customer requests into account in all phases of the design, construction and programming. And the results are amazing! All defined reference values were reached or even exceeded.