Contributor: Alex Edwards, Marketing & Communications Manager, Rotating Equipment Services, Sulzer
Emergency weekend repair saves patients’ operations
Hospitals, especially those with designated major trauma centers, depend on their emergency theatres to deliver life-saving treatment. So, when an air handling unit (AHU) needed an overnight repair, Sulzer engineers were able to complete the project and ensure no operations were cancelled.
Sulzer often works with hospitals on planned maintenance tasks, repairing and replacing fans, motors and other equipment as the need arises. Through these partnerships, the company was recently asked to assist with an urgent repair.
Maintenance engineers at the hospital had investigated a vibration problem with an air handling unit that supplied emergency theaters. Having identified a catastrophic bearing failure, they realized that an immediate repair was required and called the local Sulzer Service Center.
Diagnosing the issueThe initial site visit was made on the Saturday when they assessed the damage and checked the dimensions of the shaft. The fan within the air handling unit, which was originally manufactured in 1970, measured approximately 1.5 meters in diameter and was supported by a 1½ inch (38 mm) shaft.The original bearings were non-lubricating pillow block bearings which had been recommended by a local supplier. These had failed due to a lack of lubrication, which resulted in damage to the shaft and a considerable amount of vibration in the fan unit.
Sulzer proposed the manufacture of a new shaft and the installation on new split bearings that would improve the performance of the fan and reduce the maintenance requirements for the future.
Recommended treatmentThe duty engineer at the hospital approved the suggested solution and urged the repair to be completed at the earliest opportunity. Sulzer immediately ordered the new bearings and the replacement shaft was manufactured at the local service center overnight.On Sunday, the engineers returned to the hospital with all the new components and installed the shaft and bearings. With the new parts in place, the fan was checked and dynamically adjusted for balance and the final vibration results were sent directly to the duty engineer as confirmation of the completion of the repair.
Paul Stevens, Sales Engineer for Sulzer, comments: “This repair was all about speed and delivering a robust solution that would last for many years to come. Understanding the needs of the customer and the importance of completing the repair on time is a specialty of ours.”
Sulzer uses a variety of balancing equipment and vibration analysis software to ensure comprehensive data is provided to the customer. Following guidance from ISO 2372 (10816), the vibration testing results are categorized into one of three groups which are prioritized using a ‘traffic light’ sequence:
- Critical – Red – above 7.1 mm/sec – Immediate attention is required
- Warning – Amber – Above 3.5 mm/sec – Attention is required at the earliest opportunity
- Normal – Green – Machinery is operating in a satisfactory condition
Savings costs and time
For every hour that the emergency theatres are out of action, there is a cost of GBP 2’500 (USD 3’200) per hour as well as the inconvenience to patients of having to rearrange operations. By completing the repair over the weekend during a planned maintenance period, Sulzer helped the hospital to avoid these costs and return the operating theatres to the medical staff.
Since the repair, the slightly smaller AHU for other theaters at this hospital was also inspected, identifying a similar level of vibration. To resolve this, Sulzer proposed a replacement shaft and split bearings to be installed during a planned maintenance period, minimizing downtime within the department.
Paul Stevens, concludes: “The repair of the shaft and bearings was completed by 5 pm on Sunday and the speed of the repair was very much appreciated. In fact, the Theater Manager advised us that we had avoided having to cancel up to nine operations that were planned for Monday.”
Sulzer is the leading worldwide, independent service provider for large rotating equipment. With technically advanced and innovative service and maintenance support solutions, Sulzer provides a turnkey service that provides its customers with the peace of mind to focus on their core operations.
Included in this package is a highly efficient and dependable high-voltage coil manufacturing and supply service, delivered from a purpose built facility within the Birmingham Service Centre, UK. It is recognized for producing very high quality coils for high voltage motors and generators; designed, manufactured and shipped by a highly skilled and dedicated team to ensure fast and reliable service.
With an in-house copper rolling mill, Sulzer customers can benefit from round-the-clock manufacturing to ensure that every coil is delivered on schedule. In conjunction with constant quality control and full HV on-site testing facilities, Sulzer can deliver quality, precision and speed, any time, day or night.