TraKuBe

Development of a transport-optimized plastic tank for small wastewater treatment plants

Small wastewater treatment plants are often used where there is no central sewage system. They often consist of monolithic tanks made of low-density polyethylene (LDPE) using rotary sintering and the internals required for wastewater treatment. Transporting finished systems to the global site is expensive because the transport volume is equal to the container volume and thus only a low packing density is achieved. The transport volume becomes significantly smaller if multi-part and stackable containers and built-in modules are used.

The aim of the joint project between the company Batchpur GmbH & Co KG and the ILK was to develop a small wastewater treatment plant with a multi-part tank system and a suitable installation module for wastewater treatment. As the tank was to consist of two halves in the future, a connection and sealing system was also developed. This was designed in such a way that it can be used on site under construction site conditions and remains reliably tight throughout the entire utilisation period of the small wastewater treatment plant.

The result of the project is a stackable tank half developed in line with requirements and production. Resistance welding with an integrated heating element was selected for the connection in order to be able to compensate for unevenness in the connection area. In joining tests at element level, process parameters and characteristic values were determined for the mathematical strength verification of the structure and the sealing concept was qualified. The joining technology was validated under long-term stress on manufactured substructures of the container half.