Research And Insight
Solving Pump Operational Challenges in Extreme Conditions
In Alabama, a major industrial facility operates six horizontal split case (axially split between bearing) chilled water pumps in a non-climate-controlled mechanical room. With room temperatures soaring up to 110°F at 100% humidity and the pumped chilled water at 40°F, the facility faced significant operational challenges.
Key Issues
The primary challenge identified was condensation due to the vast temperature difference between the room and the chilled water. This condensation led to water infiltration into the pump bearings, necessitating frequent pump servicing and resulting in costly downtime.
One proposed solution was to insulate the pumps, particularly the bearing frame, using an insulation box or enclosure. However, this approach risked trapping heat generated by the pump bearings, potentially causing bearing failure.
Grundfos NBS Pump Solution
The Grundfos NBS pump (split-coupled horizontal end-suction) not only meets the current performance requirements but also offers several advantages that address the facility's maintenance concerns:
- Industry-Leading Efficiency
Utilizing advanced Computational Fluid Dynamics (CFD) software and 304SS investment cast impellers, the NBS pump achieves superior Pump Energy Index (PEI) values as per US Department of Energy standards.
2. No External Lubrication Required
The hydraulic balancing holes in the impeller and integrally cast diffuser vanes help reduce axial forces and eliminate the need for bearings in the pump (motor bearings are adequate for handling axial thrust).
3. Integral Drain Port
The motor stool/bracket features an integral drain port to remove any water accumulation due to condensation, preventing water-related damage.
4. Compact Footprint
With an optimized design, the NBS pump occupies 35% less space than a frame-mounted pump, enhancing its space efficiency without compromising performance or serviceability.
5. Lifetime Alignment Guarantee
The keyed pump impeller and motor shafts, combined with a rigid clamshell coupler, ensure precise alignment, eliminating the need for laser alignment and reducing installation time.
6. Easy Serviceability
The axially split rigid spacer coupling and back pull-out design facilitate rapid mechanical seal access without disturbing the pump liquid end and motor, streamlining maintenance.
The Grundfos NBS is a state-of-the-art end-suction pump designed to excel in four critical areas: ease of installation, efficiency, reliability, and serviceability. These features make it an ideal choice for mission-critical applications in challenging environments.