Problem: The old Tyrolean intake structures for the power plant were getting clogged and damaged during flooding season.

Solution: The weir design was changed and the Tyrolean intake structures were replaced with custom Coanda Screens.


Tyrolean Screen

Introduction

Trabzon Seydioglu hydroelectric power plant has been operational for  around ten years. The intake structure for the hydroelectric power plant was first designed be a Tyrolean structure. However during flooding season, the Tyrolean intake would get clogged and get damaged by the trash, rocks, and wood. This was mainly  due to the large slot size of the Tyrolean screen.

Larger rocks would get lodged in between the profiles and due to corrosion they would lose structural integrity and bend causing more issues. Thus, there were frequent shutdowns at the power plant due to insufficient water intake and the engineers that were responsible for the power plant decided that the Tyrolean intake had to be replaced.

Tyrolean Screen


Weir Design

The manager of the power plant contacted ADENCO for our Coanda screens and asked if Coanda Screens would be a good solution for their application. Our team went to the power plant to measure the required capacity and the weir dimensions. Then, the water composition was analyzed to figure out if a special coating would be needed for the application.

One of the main challenges of the project was the redesign of the weir structure. The typical Tyrolean screens are placed at around 17 degrees from the horizontal plane. However, Coanda screens utilize a steeper drop around 50 degrees to maximise efficiency. Thus, the weir had to be raised and the weir gap had to be shortened to place the screen.


Support Structure

The team devised a plan to redesign the weir to allow the Coanda screens to be installed. First, a preliminary steel structure was installed. Then, concrete was poured in between the steel supports. Then, two steel plates were installed to the support structures with brackets.

To prevent corrosion, these plates were painted with an anti-corrosion coating. This support structure allowed the Coanda screens to be fully supported in most cases. Lastly, the Coanda screens were installed to the new support structure.


Results

Compared to the old Tyrolean intake, the Coanda intake screens do not clog. They are self-cleaning, so they require minimal maintenance. They are more resilient to extreme flooding. They are corrosion resistant. With the new Coanda intake screen solution, the power plant has been experiencing fewer shutdowns and they have been quite satisfied with them since 2019.