Saalfelder Werkzeugmaschinen GmbH (Samag) in Germany produces crankshaft bearing caps for a large German automotive manufacturer. For the cleaning of these components, the company not only requires a cleaning system with the highest cleanliness results and a short cycle time, but particularly also with a high level of energy efficiency.
Samag invested in a continuous cleaning system from the manufacturer BvL Oberflächentechnik GmbH in Germany. In the American market, several automotive suppliers have also been using the efficient cleaning systems from BvL in recent years, e.g., ZF Sachs Automotive Méxiko S.A. de C.V in Ramos Arizpe, Mexico, and KSM Castings NC Inc. in Shelby.
Special technical measures were installed in the cleaning system for Samag in Germany to optimize energy consumption and emissions.
In addition to insulation on the pipes, optimized drying and the introduction of an automated standby state, the cleaning system was equipped with the exhaust air management specially developed by BvL. The energy savings promised by BvL have been more than confirmed: The system has now been in operation successfully for one year and provides a proven energy saving of 20 percent compared to a similar system without these energy efficiency measures. The absolute savings is 10.4 kWh, which means the total consumption of the system is only 41.2 kWh instead of 51.6 kWh. Additionally, water consumption was reduced by a full 20 percent and noise emissions were decreased by 5 dB(A).
Based on these positive experiences, Samag decided to buy another cleaning system of the same type from BvL in October 2015. Moreover, all cleaning systems in the production workshop were retrofitted with the special exhaust air management in 2015 to achieve further energy savings.
Andreas Weigel, head of maintenance at the Samag Group, explained the requirements for the energy efficiency increase, reporting on the results of the measures together with Peter Stahl, sales engineer at BvL Oberflächentechnik GmbH.
Mr. Weigel, BvL offered you special measures for increasing the energy efficiency of the cleaning systems. Why did you decide to implement these?
We have a very strong focus on the responsible use of energy resources in our company. And of course we also keep an eye on the total operational costs of a system. The amortization period of the energy saving package is very attractive, making it a worthwhile investment not only with regard to environmental protection.
Which specific results have been achieved?
In total, we can save around 71,000 kWh/a in a three-shift operation. That corresponds to an impressive annual CO2 saving of 41 tons. Compared to other industry standard systems, this can lower the expected consumption by 20 percent.
BvL implemented several energy saving measures for the system. Exhaust air management seems to be the central element. Mr. Stahl, what exactly does that mean?
The “exhaust air management” developed by BvL reduces the volume of exhaust air, which consumes the most energy in a continuous cleaning system. To achieve this, the system measures the moisture content in the drying zone and extracts only as much air as necessary for the process. This creates the best possible moisture level in the system and the volume of hot exhaust air — and therefore energy — blown out of the system is kept as low as possible. The warm and moist air and with it, the energy, remains in the system.
In addition to energy savings, the requirements specification from Samag also limited the noise emissions directly at the discharge zone to 79 dB(A). What were the results of your sound level measurement, Mr. Weigel?
The sound level measurement was carried out at the measuring positions in line with DIN 45635 part 1 as well as at a “user-related” measuring point defined by us. According to the DIN measurement, the system achieves a workplace related emission value of LpA: 68.6 dB(A). It is interesting to compare this to a structurally similar system from 2012 without optimization as this reached a value of 73.6 dB(A). This proves that the significant noise reduction is due to the optimization measures. In the same way, the BvL system achieved a value of 75 dB(A) at the “user-related” measuring point directly at the discharge position defined by us. This is below the limit value stipulated in the requirements specification. The reduced noise emission is particularly important in our company as we are continuously striving to improve the working environment for our employees.
Which measures did you take to reduce the noise emissions, Mr. Stahl?
The speed of the fan in the drying phase was reduced. The perfect ratio of low flow and high temperature provides an optimum drying result with minimum noise emission.
How does Samag integrate the energy savings into existing production systems, Mr. Weigel?
We are absolutely satisfied with the convincing results of the extensive tests and measurements on the cleaning system that we commissioned one year ago. As a result, we not only ordered another system equipped with this energy saving package in October 2015, but we will now also retrofit all our BvL cleaning systems with the specially developed BvL energy saving packages to increase the energy efficiency of all our production systems.
Energy and noise before and after the optimization measures as well as individual results of the optimized drying process and the BvL exhaust management.
FOR MORE INFORMATION: bvl-group.de