At the beginning of December 2021, the second large KR 2842 catenary screen manufactured by ESMIL was installed and put into operation at the Kelenföld pumping station in Budapest. The choice of this equipment was based on a number of technological advantages, such as:
- the ability to work under enormous loads,
- the unique design of the chain, which allows to adapt to the size of the debris in the wastewater stream and work without jamming,
- the positive experience of using a similar screen operated by the water utility since June 2020.
This screen is notable for its dimensions – it was designed for a 3.2 m wide and 4.5 m deep channel, while the device’s capacity is up to 5000 l/s (18,000 m3/h) with a clearance of 20 mm. To cope efficiently with high loads, the number of rakes in the screen construction has been increased (500 mm pitch).
The employees of the Budapest water utility were eagerly looking forward to the installation of the new screen. First months of its operation fully met their expectations, but it should also be noted that their responsible attitude to the new equipment deserves the highest praise!
When developing the design of the catenary screen installed in Kelenföld, ESMIL specialists took into account the high hydraulic loads, which the screen undergoes during heavy rains. To ensure the necessary durability of the equipment, the following progressive solutions were applied:
- High hydrodynamic performance of the filter cloth. The screen cloth is made of a drop-shaped profile (production material – stainless steel). This ensures a high throughput of the screen even with a relatively small spacing (20 mm). The cloth dimensions are 2650×3000 mm with an accuracy of +/- 1 mm.
- Unique screen chain design. The flexible chain is an innovative solution, which allows the chain to work with only one fixed axis of rotation both as a loadbearing and supporting structure for the rakes. The chain is made of high-strength materials and it highly exceeds other types of chains by operational parameters.
- The ability to adapt to the dimensions of the debris in the stream. The “flexible chain” design guarantees trouble-free operation of the equipment (without jamming) even with large debris in the stream.
- Reliable automation and protection system. ESMIL catenary screens are equipped with a control system operating in various modes. Due to the possibility of adjustment by wastewater level or by time, the rakes can clean the filter cloth with a different intensity. The screen is equipped with a mechanical overload protection device, and thermal protection of the drive is provided as the second stage of protection. All this allows the equipment to work reliably with little or no need for maintenance personnel.
The screen was delivered to the water utility as assembled construction. Before delivery, the screen passed the necessary checks and tests at the plant in Poland. Just like in case of the Andalföld pumping station, its installation and subsequent commissioning were carried out within a few hours.
In order to confirm and ensure the successful installation and operation of the screen, ESMIL employees visited the pumping station several times and performed the necessary measurements to perform a 3D simulation of the screen’s position and its interaction with existing equipment.
The installation of ESMIL catenary screens in Budapest is one of the priorities of the Hungarian representative of the ESMIL Group, Ekosvit Centrum Kft. It should be emphasized that the Budapest Water and Sewerage Plant plays a major role in discharging properly treated wastewater into the Danube. The ESMIL Group is proud that the provided catenary screens also contribute to keeping the Danube basin ecologically clean.