In recent years, there have been many innovations in implementing newer materials as well as improvements in hydraulics. Improving pump designs is an ongoing process with designers looking for increasing performance by a few percentage points. The goal of the present pump manufacturers is to offer higher efficiency and reliability, but replacing an older pumps with newer pumps can mean higher costs. The focus for replacing the internals of the pumps with improved design has gained prominence since many of the components, like the casing and rotor, of the existing pumps can be reused. So instead of replacing the entire pump, it can be upgraded or retrofitted. When it comes to an upgrade, the first thing that should be considered is the return on investment which includes the initial investment, operating costs, and the reduction in energy consumption due to the improved pump performance.
Also, sometimes the simplest of upgrades can improve pump efficiency from 5-10% or even more. Such upgrades can yield significant savings on maintenance and repairing cost of the pumps and the benefits of these upgrades can be observed with less downtime than more complex upgrades. A few examples of these simple upgrades are custom coatings for internal and external components, shafts, seals and bearing modifications.
Time to Upgrade
Before considering the upgrade of an existing pump, one should analyze the existing pump performance to make an informed decision on how much needs to be invested and what will be the payback period. Sometimes, small modifications can eliminate the necessity of an entire pump upgrade.
Eventually running pumps will have to be replaced by newer pumps over a period of time because of the natural wear and tear of use. Figure 2 shows impeller degradation due to different operational causes. But it needs to be ensured that one can get maximum benefit from the maintenance or upgrade of a running machine.
Things to remember while considering an upgrade:
- Significant Performance Enhancement: If you are upgrading for significant performance enhancement, then it may be beneficial to upgrade existing pump even though the running pump performed satisfactorily. In another circumstances when efficiency of the running pump becomes a major issue then replacement of pump is completely justifiable.
- Maximum Capital Gain: Here, it is required to consider several factors like running pump performance, physical condition, capital for new pumps, payback period etc. Another important consideration is to think about cost effectiveness of continued maintenance of the existing equipment or replacement.
- Numerical Simulations to Identify the Need to Upgrade: While considering an upgrade, it is always better to simulate the running pump using commercially available turbomachinery design platform such as AxSTREAM® and identify the cause of performance degradation. Then, performance enhancement can be achieved by redesigning the identified components. The redesign will help in making an informed decision on the performance improvement. Based on this, further analysis can be done to check on the overall return on investment considering an update versus a complete replacement. Different components of a pump (impeller, diffuser, volute, bearings, shaft etc.) can be numerically simulated and redesigned using different schemes of the pump design to get maximum efficiency for specific applications. For example, different layouts like diagonal flow pumps, radial flow pumps, axial pumps, single or multistage pumps (Figure 3) can be considered based on the application and requirements by using AxSTREAM® in which different hydrodynamic schemes, bearings, rotor-dynamics, 3D-flow analysis can be easily carried out within a very short duration of time and which can give good returns on investment.
Interested in learning about how AxSTREAM® can help you? Follow the below link to learn more or contact us at Info@SoftInWay.com !