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ŪPIUS Check case study
Otto Vollmann GmbH & Co. KG in
Gevelsberg
Cooling water optimization with cost savings
 Otto Vollmann GmbH & Co. KG, a medium-sized group of companies, produces high quality components and assemblies at three sites in Germany. Within the framework of PIUS-Check, the group has improved the cooling system for its zinc baths and the utilization of cooling water at its site in Gevelsberg.
Its main clients come from the automotive supply
industry, the lighting industry and the telecommunications industry.
The basic technologies used are injection moulding and metalforming.
The company also provides a variety of complementary services to
supplement the basic technologies it uses, such as tool making and
speciale purpose machine.
The electroplating plant at the production facilities is used for galvanizing, colouring and gloss pickling. Cooling water is required for these processes, as the acid zinc baths warm up during the electrolytic galvanization process. A once-through cooling system is used to guarantee an optimum operating temperature for the baths. The cooling water used here is then reused to rinse the galvanized workpieces in a subsequent rinsing cascade. Up until now, the quantity of water flowing through the system was determined by the maximum cooling requirement of the zinc baths. Otto Vollmann therefore used approximately 2,000 cubic metres of water per annum.
PIUS Check determined that maximum cooling was only required during a very small number of operating hours. Now the cooling system is being designed around the rinsing water requirement. The smaller quantity of water guarantees adequate cooling and the company has been able to reduce its water consumption by 1,500 cubic metres. Today it requires only around 500 cubic metres of water per annum. If the cooling requirement increases, then the once-through cooling plant can be supported by a cooling system. The cooling system is located directly next to the electroplating plant. Otto Vollmann has invested 1,000 euro in the conversion and is saving approx. 3.50 euro per cubic metre of water.
In addition to this, the company is now operating
its flow rinsing process after the colouring bath using the rinsing
water that has already been used in the passivation process. This
saves around 1,200 cubic metres of water per annum.
The drums with the workpieces that are to be galvanized
following pickling, an acid pretreatment process, are also predipped
in the stationary rinser of the zinc bath. In this so-called "predipping"
process, the workpieces are transported to the stationary rinser
before the processing bath. By dipping the product in the rinser
beforehand, approximately the same quantity of electrolyte is introduced
into the electrolytic processing bath as that removed by the pre-dipping
stationary rinser in the subsequent rinsing procedures. The system
leads to a recycling of electrolytes by up to approx. 50%.
Further potential exists in the improvement of the
tank positions. Investigations are also being carried out with a
view to extending the plant to include zinc and iron baths, as well
as the potential for a new waste water concept for waste water treatment.
The changes that were made as a result of the PIUS
Check show that huge savings of 2,700 cubic metres of water can
be made even with a comparatively small investment of 1,000 euro.
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