Gebr. Lemberger Entsorgungs- und Abwassertechnik GmbH invests in own recycling system. It is a family-owned company based in Munich that offers its services throughout Bavaria. This includes the cleaning of drains, pipes and sewers as well as the disposal of liquid waste.

Reduction of disposal costs

In order to reduce disposal costs, the company decided in 2021 to recycle the sewer flushing material itself in future. To this end, in addition to the headquarters in Munich, a further location was rented and the company BIBKO®, business division INFRATEC, was com-missioned to design an appropriate recycling system. This recycling system has now been delivered and put into operation.

Task and objective

The task was to design a recycling system that would achieve the following goals:

Reduction of the disposal volume

  • Improvement of the allocation value Z (in the recycled material)
  • Reduction of disposal costs

Installation location

Since a hall was already available at the rented location, the recycling system was planned in this hall. This ensures problem-free operation of the system even in winter. 

The already existing recess in the hall was to serve as the installation position. The struc-tural design of the recycling system was adapt-ed accordingly so that a recessed installation was possible. This enables optimal emptying of the vehicles.

Hall with recess in the floor 

Machine concept

In order to achieve the defined goals, a 2-chamber recycling machine of the type IT-4000/2 with a mechanical pipe of approx. 20 t/h and a spiral conveyor type IT-WDF-6 as material discharge was planned. The sewer flushing material is fed via a feed hopper. The resulting process water is led into a separating basin and then discharged. 

Recycling process

The recycling process consists of a total of two process stages:

  • Prozess stage 1: Material feed
  • Prozess stage 2: Material recycling

Machine concept with process stages

Process stage 1: Material feed

A hopper construction with a feed area of 3 m x 3 m is used to feed the material into the recy-cling machine. 

A large-meshed grating in the area of the feed surface prevents large pieces of material from entering the plant on the one hand, and on the other hand it complies with the accident pre-vention regulations.

Vehicle during rinsing

Prozess stage 2: Material recycling

The actual washing process takes place in the BIBKO® recycling machine. This system con-sists of a 4 m long machine trough that is divid-ed into two (washing) chambers. 

First, the material enters the 2.2 m long pre-washing chamber of the recycling plant. This contains a water bath. In a wet-mechanical recycling process, a rotating spiral conveys the material through the water bath and segre-gates it.

At the same time, water flows through the chamber in countercurrent. In the process, the organic components and the mineral com-ponents ≤250 µm are washed out and dis-charged together with the excess process water via an outlet channel.

Recycling machine with oulet channel 

The mineral components >250 µm remaining in the system are removed from the pre-wash-ing chamber via a bucket elevator and fed into the main washing chamber. There, similar to the pre-washing chamber, the main washing process takes place, in which the material is again mechanically conveyed through a water bath. In order to achieve an optimal washing result, water flows through the chamber in countercurrent. 

A second bucket elevator removes the washed material from the main washing chamber and feeds it to the spiral conveyor.

Recycled material

The material is dewatered via this conveyor and conveyed into the material box. The ma-terial is then available again as secondary raw material.

After Gebr. Lemberger Entsorgungs- und Ab-wassertechnik GmbH had decided internally to recycle sewer flushing material itself in the future, the following parameters were defined:

Parameter 1: Installation position

The rented hall already had a recess in the floor. The recycling system was to be designed in such a way that this recess could be used as an installation site.

Parameter 2: Objective of the system

The recycling system should reduce the dis-posal volume and improve the allocation value Z in the recycled material in order to reduce disposal costs.

With the BIBKO® INFRATEC – recycling system supplied, the parameters defined in advance were achieved in full. This now leads to reduced costs in daily operation and makes the purchase of the BIBKO® INFRATEC – recycling system a profitable investment.

Vehicle during rinsing

BIBKO® Umwelt- und Reinigungstechnik GmbH – Geschäftsbereich INFRATEC  

+49 7062 9264-0