Gearbox in a weir

Weirs provide sufficient water depth in rivers and canals to allow navigation. Weirs also allow the water to flow more slowly, so that the riverbeds and bridge piers are less likely to be washed out or under. There are two gears in each weir. These regulate the water level depending on the weather conditions. The gears are set in motion every hour by raising and lowering the single or top weir. Using the example of a weir in Neckarsulm, Germany, GIEBEL adsorbers with and without valves were tested and observed under real conditions.

Plant data

  • 4x gearboxes with an age of approx. 20 years
  • Oil volume in the gearbox: approx. 250 liters / 60% filled
  • Cycle every 2 hours
  • Influence of sun and weather indirect present
  • Long downtimes, infrequent operation

Gear without Adsorber

Due to the strong temperature influences from the environment and the long downtimes, the formation of condensation water is strongly favored. The air drawn in during cooling and the constant contact with the environment ensure that moisture in the air flows into the gear unit and liquefies during cooling. This leads to corrosion with particle abrasion and thus damage to the gear unit. The operation of the weir is thus no longer guaranteed and generates high maintenance costs.

Function at a weir

Especially when operating on a weir, the respiratory dryer must be properly selected. If the gearbox is used infrequently, the desiccant it contains must be protected from the ambient humidity in order to achieve a maintenance interval of several years. At the weir in Neckarsulm, two adsorber types were tested over a period of 9 months. On the one hand an adsorber WITHOUT valves and on the other hand WITH valves. The adsorber of the same size with valves was only loaded to approx. 15% after the same period of time. A maintenance interval of 3-4 years can thus be assumed without further ado.