Retrofitting planetary gearboxes at test sites

In a bid to become as energy efficient as possible, Anglian Water asked Bravini to find an alternative to the old screw pump gearboxes at their trial site in Maldon. Planetary gearboxes were identified as the answer and since their installation, running costs have been reduced and pump efficiency has increased by 16%.

Anglian Water installed the planetary gearbox from Brevini into the trial site at Maldon in Essex
Anglian Water installed the planetary gearbox from Brevini into the trial site at Maldon in Essex

As part of a wide reaching raft of proactive measures aimed at minimising its energy usage, water and wastewater services provider Anglian Water has decided to replace old screw pump gearboxes with new innovative planetary gearboxes. Work has been carried out on a trial site at Maldon in Essex. Working closely with Brammer UK Ltd, the UK’s leading supplier of industrial maintenance, repair and overhaul (MRO) products and services, Brevini has identified a suitable gearbox and developed a mounting bracket which allows the new gearbox to be installed without the need to re-engineer the original pump.

Anglian Water is tackling issues such as climate change, going to great lengths to ensure it runs with the highest possible levels of energy efficiency. In a bid to further its efficiency, Anglian Water has employed the help of gearbox manufacturers Brevini through MRO specialist Brammer.

Working with Brevini and Brammer, Anglian Water identified sites where conventional screw pump gearboxes were running with poor efficiency. The benefits of replacing these older gearboxes with Brevini’s highly efficient planetary gearboxes were obvious as they are able to run from a smaller motor than conventional gearboxes and can be retrofitted to existing structures which in turn decreases the cost of installation.

Jon Snaith, UK sales and marketing manager for Brevini comments: “Brevini UK Ltd are working very closely with Brammer on a number of projects similar to this one, it is very important to develop a partnership where different strengths are brought together to provide the customer with high calibre solutions.”

A trial site at Maldon in Essex was identified where a screw pump gearbox was due for replacement. Following an on-site consultation, Brevini was able to recommend a suitable gearbox and design a mounting bracket which would allow it to fit directly onto the existing structure. The output shaft was designed to be of the same diameter as that on the previous gearbox, while a backstop was fitted to prevent the screw running backwards when it stops.

Planetary gearboxes are capable of producing very large reduction ratios (they can reach 15,000:1) meaning that they are ideal for driving heavy rotors at slow speeds. Producing up to 800 kNM of torque the gearboxes can produce the same power as large ‘worm and wheel’ gearboxes despite being far smaller – often 60% lighter than their equivalent. Brevini gearboxes have a lifetime of over 100,000 hours when they are in constant use, keeping maintenance down to a minimum; one oil change per year is all that is needed.

Since the installation of the new gearbox, the Maldon site has reported that the pump is running with 16% more efficiency than previously, the gearbox running to an efficiency of 96%. Running costs have been greatly reduced as the new gearbox only requires 13.4 amps compared to the previous 16.6. This equates to a 2.1 kW reduction in running power and a saving of £1,400 per year, a potentially significant saving if all the company’s gearboxes were to be replaced.

Jon Snaith added: “The new planetary gearboxes offer multiple advantages over their older helical counterparts – not just in terms of efficiency but through their compactness, robustness and longevity even in the most demanding applications, as well as the minimal maintenance required.”

Following the success of the trial installation, Anglian Water is currently identifying similar installations throughout its sites where other replacements can be made.

Mark Francis, leading energy auditor at Anglian Water, said: “With current energy issues, it is extremely important that we keep our energy use to a minimum. Often to replace old installation is costly and time consuming leading to a long down time. Brevini were able to supply a gearbox that reduced our energy usage without any costly engineering to our existing structure, the savings that will be made in a small amount of time will pay for the original installation costs.”