Less hot air

Understanding how electrical and hydraulic devices work and reducing the amount of energy they use will have more impact than changing lightbulbs, reports Julia Pierce.


Steady progression rather than shattering innovation has always been the key to the success of the fluid power and hydraulics industry. However, like all companies in the UK, energy saving is becoming more important to those operating in this area.

‘The hydraulics and pneumatics industry in the UK is growing,’ said Ian Morris, director of the British Fluid Power Association. ‘However, there isn’t really ever any radical technological change, more a trend towards steady progress rather than having any eureka moments.’

This view is echoed by Paul Taylor, managing director of fluid power solutions providers Hyquip. ‘The technology used by operators is certainly being refined but it doesn’t really evolve rapidly,’ he said.

Yet as fuel prices yo-yo, leaving companies periodically facing increased costs, the problem of energy saving is fast becoming the most talked-about issue around. Fluid power alone is a £16bn industry worldwide. According to statistics from Purdue University in the US, each 10 per cent improvement in the energy efficiency of current uses of fluid power would save about £3.5bn a year in energy outlay.

While many firms are making gestures within their plants such as using energy-saving lightbulbs or turning down their air conditioning, by failing to refine the operation of their machinery they may be missing the chance to make a real impact on fuel costs.

‘There is a lot of hot air being spoken about the environment and energy conservation,’ said Morris. ‘People are rushing down avenues to do with energy savings but the real need is to look at the whole energy cycle.’

‘The idea of energy efficiency has been around for a while,’ said David O’Loughlin, technical manager and consultant at the National Fluid Power Centre (NFPC). ‘Controlling the output of blowers, fans and centrifugal pumps by throttling the flow can waste a huge amount of power compared with controlling the output by reducing the running speed.’

Finding a solution to the problem of how to stop energy waste and make cost savings can be hard, particularly with machinery such as pumps that are constantly in operation.

‘When you walk on to a shop floor you can hear all the hydraulic pumps running,’ said the NFPC’s O’Loughlin. ‘They are turned on in the morning and stay on all day. It may be possible, however, to start the pumps only a few seconds before they are needed and then stop them as soon as that particular process step has been completed.

‘Hydraulic motors are often repeatedly turned on and off during a process cycle as a matter of course. But the mechanics of hydraulic pumps are very similar to hydraulic motors; the hydraulic motors survive the cyclic treatment and so can the pumps. The electric motor controls might need some attention to allow this cyclic operation but the problems here are well understood and the solution has additional benefits.

‘With more understanding of how hydraulic and electric devices work, both individually and together, you can reorganise the control systems to save energy. People can be too afraid to change their hydraulic circuits and control systems but really, machines are eminently tuneable.’

Meanwhile, correct filtration of fluids within this equipment can also make a considerable difference to the amount of energy used and the lifetime of the equipment itself.

‘To meet future challenges, the hydraulics market needs better reliability and management of equipment with less maintenance,’ said Mike Day, applications manager for the Aerospace and Transportation group at Pall Europe. ‘Energy efficiency and sustainability are key. Particles of dirt in the oil are the most important factor in the failure rate of equipment and to achieve the improvements in performance and reliability being demanded. Hydraulic systems must operate with clean fluids. However, greater efficiency through reduced clearances means there is an even greater sensitivity to dirt, meaning cleanliness is even more pressing.’

To make sure that machinery is not contaminated, manufacturers have gone back to the start of the process, managing cleanliness from the very beginning.

‘A holistic approach is required,’ said Day. ‘The mantra is “design it clean, build it clean, keep it clean”. By minimising wear from dirt in all the processes the amount of intervention needed should be minimal. However, to achieve this you need set specifications for cleanliness, and to monitor the system to see that it is being maintained and effect prompt corrective actions if it isn’t.’

Recognising the importance of energy conservation, manufacturers are now designing their equipment with this in mind.

A good example is the recently launched IT62H integrated tool carrier from Caterpillar. This features a load-sensing hydraulic system that automatically adjusts to operating conditions to provide only the hydraulic flow requested by the operator, giving them an improvement of five per cent in the case of fuel efficiency.

A two-pump hydraulic system provides one pump for the hydraulic system and the other for the steering system, with no priority one over the other. This ensures full flow to both steering and implements, guaranteeing power is supplied when and where it is needed.

However, the issue that may yet have an impact on the market is ensuring the right equipment is chosen for the job in hand, making sure the process is as efficient as possible.

‘It used to be that manufacturers sold their products through a traditional distributor with the expertise to deliver systems to market and find the customer the right product for the job,’ said Hyquip’s Taylor. ‘Then the focus moved towards single sourcing companies.’

He believes that the value added by making sure that customers receive advice and products tailored exactly to their needs means they are now demanding a return to traditional practices.

‘Customers were finding that they didn’t get the same access to expertise so it has all moved full circle. The market is re-evolving,’ he said.

Given pressure from both pricing and government to reduce energy use, like almost every other section of engineering, it is not surprising that the issue has come to the fore.

The evolutionary progress of technology in the sector may not at first seem able to adapt to such a demand but by making changes such as auditing the use of their existing equipment and installing new, more efficient versions, both users and manufacturers could have an important part to play in reducing energy use without the need for untested technology.