We have not provided a crane system for a sludge plant in the past 30 years, but this does not prevent us from analyzing the details hidden in the crane case from a professional perspective. The analysis of crane systems under different working conditions can, on the one hand, improve our own experience, and on the other hand, it provides a window of understanding for customers who are interested in crane systems. Today’s case is a sludge plant in Switzerland. When they upgraded the factory system, they introduced a bridge crane system, and this crane system will become the key to the success of the system upgrade.

Table of Contents

• Why bridge crane
• What we learned from this case

Why bridge crane

In fact, the crane supplier supplied the sludge plant with two underslung bridge cranes and nine monorails, including chain hoists. And this sludge plant has been treating wastewater from a famous resort.

In order to adapt to the changes of the times, the sludge plant decided to upgrade the plant system to a state-of-the-art membrane bioreactor unit, a wastewater treatment method that combines membrane technology with suspended growth bioreactors. Crane systems are integrated into the mountain on multiple levels to perform the heavy material handling that is integral to the process.

Both cranes are frequency controlled and have extremely low headroom requirements to navigate narrow and enclosed corridors while transporting bulky bellows. Hoist models GCH2500 in single fall and GCH1600 in double fall were chosen for the specialist project. The crane is rated 2m/M5 and is designed for harsh environments and high loads, while the equally durable hoist is rated 1Bm/M3.

Due to the short construction period between Easter and Christmas, the entire construction project was carried out in several phases over three and a half years. The resort is a small village with a population of about 6,000, but the population swells to 60,000 during the winter months from December to April, during which time the sewage system must operate at full capacity.

The installation of the lifting equipment took place in a short window of less than four weeks during the summer months. There was no flexibility and we had to complete successful installation of the cranes, monorails and hoists to the day.

The system will be in use for at least 20 years, with parts made "as small as possible" so they can be transported to the site by truck, then unloaded by electric forklifts and transferred to the tunnel system trucks.

What we learned from this case

It can be seen from the case description that despite the different fields of work, the role played by the crane is no different from other fields. In terms of the crane structure used, the lower suspension system is a very mature system, and low headroom designs also appear in many bridge crane types. If the customer can describe the working condition information in detail, we believe that our engineers will be able to design the most suitable crane system for the customer. According to the special environment of the sludge plant, we can also roughly infer some quality requirements for cranes in this environment:

• Stability and reliability: Overhead cranes need to have high stability and reliability to ensure continuity and safety during the sludge treatment process. The design should consider factors such as material selection, structural rationality, and manufacturing process reliability to ensure that the crane can operate stably for a long time in harsh working environments.
• Carrying capacity and efficiency: Bridge cranes need to have sufficient carrying capacity to cope with the heavy lifting needs that may arise during the sludge treatment process. At the same time, the working efficiency of the crane is also very important to ensure the smooth operation of the production line. The design should consider factors such as the crane's lifting capacity, speed control, and degree of automation.
• Safety and Comfort: The design of overhead cranes should focus on the safety and comfort of the operators. Complete safety protection measures, such as guardrails, emergency stopping devices, etc., should be provided to reduce risks during operation. At the same time, the operating interface of the crane should be simple and clear, making it easy for operators to quickly master and operate.
• Corrosion resistance and ease of maintenance: Since corrosive substances may be produced during sludge treatment, bridge cranes need to have good corrosion resistance. The design should consider the use of corrosion-resistant materials, coating protection and other measures to extend the service life of the crane. In addition, the maintainability of the crane should also be considered to facilitate routine maintenance and upkeep.

Sludge plant upgrade system, bridge crane makes great contribution