Thursday, 01 June 2023 11:51

Identifying poor assets and inefficient pumps.

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Despite the soaring prices brought on by an energy crisis that shows no signs of diminishing, ask pump and blower operators about the efficiency of their equipment, and the truth is that most don’t know – according to a leading monitoring technology provider.

The pumps, for example, might often be described as ‘working fine’ and ‘doing their job’, but is that, now more than ever, a strategy? How about saving money now, and in the future?

“The opportunity to truly maintain, protect and optimise assets is here and now, with a Return on Investment (ROI) that is shorter than ever”, says Julian Lowe from Riventa. “The cost of solving asset management challenges is on a much smaller scale than most companies imagine”.

So, just how can you make hidden costs more visible?

At minimum, put some testing in place. By obtaining accurate, quality data, this first proactive step will give you a snapshot of performance, as well as health and efficiency. Even this entry-level testing will help identify poor assets and inefficient pumps.

Riventa’s Julian Lowe added: “All we hear about at the moment, understandably, is the giant hike in energy prices, so best test your pumps (and/or blowers and turbines) to reduce energy consumption and maximise savings. This will almost immediately help identify actions to improve performance. In addition to pump efficiency, measuring key parameters such as flow rate, head and electrical power - current pump performance characteristics can be compared to ‘as new’ and ‘post-refurbishment’ conditions. This provides the same accuracy as a pump manufacturer’s test facility – but with the distinct advantage of real operating conditions”.

Across numerous industries, where for some, running pumps ‘til destruction is the modus operandi, Lowe has a point. He claims that for larger pumps, blowers and turbines, the ROI can be as little as 18 months.

Most pump and blower operators don’t know about the efficiency of their equipment, say RiventaMost pump and blower operators don’t know about the efficiency of their equipment, say Riventa

A level up from pump testing is to look at an Optimisation Service, utilising secure on-site pump monitoring equipment to provide real-time data. This enables you to start seeing what’s happening across your system by capturing data over 14-days or longer. This doesn’t have to involve tons of ‘spaghetti’. Systems can now be cable-free; up and running in around 1 hour per pump, at low risk and with minimal disruption to existing operations.

‘Realistic payback calculations’

Dr Tom Clifford from Riventa, continued: “Once in place, real-time data for each asset can be evaluated, with information-driven insights highlighting performance issues and supporting decisions. This can establish best practice recommendations, realistic payback calculations and a business case for moving forward – all backed by precision measurement and innovative analytics”.

Clifford explained how Riventa had recently worked with a food manufacturer; testing the company’s cooling system, which is split into two pumping sub-systems: factory pumps 1-5 for sending chilled water from heat-exchangers to the factory; and evaporator pumps that send chilled water from the factory to refrigeration heat exchangers.

“To test the pumps, we used the thermodynamic measurement technique (with our specialist software) to measure suction and discharge pressures either side of the pump, differential temperature, and motor input power. These measurements enabled us to calculate differential head across the pump, hydraulic efficiency and volumetric flow. Pumps were altered gradually. After each change, a test point was taken, while allowing enough time to obtain the best statistical average. Tests also involved a routine of testing performance at an incumbent set point, followed by throttling the pump to reduce its flow rate. The latter action allowed other pumps running in parallel to increase in speed to compensate, with a final test point taken at this moment”.

He continued: “Throttling meant we could observe the maximum possible flow through each pump under test, without altering the overall flow to the plant. At times this was challenging, because conditions downstream in production would change, altering the cooling load and in-turn the flow set point. Nevertheless, good quality performance information was obtained.

‘Strong case for robust savings’

“We found that all pumps were showing signs of wear. Moreover, manufacturer performance levels were not being achieved. None of the pumps we tested reached the manufacturer’s BEP (81%). In fact, the maximum pump efficiency possible was found to be 75% (achieved by pumps 1 & 2 only). Our findings enabled us to put pumps into a descending order of repair: 1, 2, 3, 4 & 5. While pumps 1-3 achieved a good relationship between power and flow, pumps 4 & 5 were not performing when at lower flows. This indicated a high likelihood of internal recirculation – from high to low pressure parts of the impeller – being caused by high wear. We were able build a strong case for robust savings through the pump refurbishment. Broadly, two options were made available:

  • Basic Refurbishment: Internal coating plus replacement of wear-rings, bearings and seals.
  • Comprehensive Refurbishment: As per the Basic Refurbishment, plus a new tailored impeller.

“We calculated that pump refurbishment would bring potential

savings of £19,200 per year, with possibilities to refurbish 2, 3 or 5 pumps”.

This is just one example of what Riventa say they are helping companies achieve across industries that also include water, power, mining, petrochemical, to name but a few.

Advanced pump monitoring and optimisation are available too, continuously focusing efforts by evaluating and understanding performance gains across priority pumps and sites. And for some organisations, full optimisation of networks is available.

‘Change in Mindset’

“Nobody wanted an energy crisis”, concluded Clifford, “but as prices soar, we are beginning to see a change in mindset about just how important it is to know how your assets such as pumps, blowers and turbines are really performing.  Initially, some basic testing might reveal some not altogether pleasing facts (!), but you can soon put yourself on a very positive course to make some seriously good, ongoing savings”.

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