Initial Situation and solution searching

In a Swiss company, called Emmi, which is specialist in producing of milk powder and cream cheese, a tank should be exchanged at the plant’s internal waste water treatment plant.

This was, amongst others, a challenging task because it had to be ensured that the corroded container should be out of operation for a maximum of 10 days. This strict timetable had to be adhered to, otherwise the biology of the sewage treatment plant would have been destroyed and thus the load on the subsequent sewage treatment plant would have become much too much.

There were lots of meetings and visits at Emmi. At these meetings it had been determined that a pipe diversion of this important buffer storage tank has to be built at first, so the tank could be taken out of operation for these few days without disturbing the clarification operation.

The planning of this diversion was made more difficult by the fact that no design drawings or pipeline plans were available.

The first approach of a solution was a lining of the tank’s inner side, which would have been very complex, however, since the HdPE panels had to be glued to the entire inner side and the seams should be welded afterwards.

This is the big advantage of a LIPP container. Steel coils, machines and accessories are transported to the building site where the tank is then constructed – the process is fast, efficient and flexible.

The awarded duplex material VERINOX, developed by Lipp, combines stainless steel and a galvanized sheet with the aid of a separating layer. Thus, the outer side of the container is made of galvanized sheet metal and the inner side is made of stainless steel. Since stainless steel is very expensive, only a small amount is needed here, so costs will be saved and the quality of the medium side will be guaranteed.

However, Emmi decided instead to remove the old container and build a new container. The main reason was the cost savings due to the decommissioning of the buffer storage tank for only 10 days. Lipp GmbH was entrusted with this task.