VSD vacuum pumps with set point control boost brick maker’s production

Installing Atlas Copco VSD vacuum pumps within its Dorket Head brickworks operation has helped Ibstock Brick maintain consistent product quality, achieve increased productivity and benefit from the added bonus of a potential 60 per cent energy saving.

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Atlas Copco's GHS VSD+ has set point controls which guarantee product quality even in demanding environments like brick making

With a 200-year brickmaking history, Ibstock Brick is now the UK’s largest manufacturer of clay and concrete building products, employing over 2600 people in the UK and USA with annual sales of almost £430m. After a period of 16 years in private ownership, Ibstock plc is now one of the biggest building materials businesses quoted on the London Stock Exchange.

The company’s Dorket Head site near Nottingham has been producing bricks since the 1860s and, following modern re-development, now has an output in the region of 95 million bricks per year. These are produced exclusively from materials extracted at its on-site quarry.

In the brick-making process the extracted clay is crushed and ground then formed into bricks by extrusion, wire cutting, drying, and firing. Water is added to the natural clay together with sand or anthracite and other pigments to obtain the final desired colour and texture. It is then compressed, shaped and extruded in a continuous strip before wire cutters then separate it into individual bricks.

It is at the auger-driven extrusion stage that the application of vacuum is important, as Daryl Leivers, Ibstock’s process improvement engineer explains:

“ It is vital to remove any air pockets in the mix that are created during the extrusion process in order to maintain the integrity and structure of the final product ”

Daryl Leivers , Process Improvement Engineer at Ibstock Brick

From liquid ring pumps to rotary screw vacuum pumps in harsh environments

Originally, the plant was equipped with liquid ring vacuum pumps, but the need to achieve a faster production line and increase output levels demanded more suction power. This would have meant installing substantially larger equipment of the same type. As Daryl Leivers points out, “To run faster, we needed more volume.” However, it became clear liquid ring pumps of that size are susceptible to extreme heat conditions, and the process environment demanded an alternative source of vacuum to achieve the desired upgrade.

The company looked at all the vacuum technology options available, including rotary vane and dry claw machines, before opting for oil-injected rotary screw pumps from Atlas Copco. Based on proven compressor screw technology, they provide significantly higher performance levels and reduced maintenance, noise and heat emissions compared to other conventional oil-sealed and dry vane pumps. What’s more, with the application of variable speed drive it was possible to tailor vacuum production to precisely meet process demand.

The decision was taken to install two plug-and-play 5.5 kW GHS 350 VSD+ vacuum pumps, one for main operation and the other as a standby machine. Each provides a nominal displacement of 390 m3/h and an ultimate vacuum of 0.35 mbar(a). The installation was completed with liquid separators and particulate filters, with all equipment subject to a total responsibility service contract with Atlas Copco.

Water handling capability was an essential requirement of the new set up. In the humid versions of the GHS VSD+ pumps, which Ibstock required, electronically controlled gas ballast and temperature management allows adaptation to the plant’s specific process and enables the pumps to handle 100 per cent water vapour at pressures above 30 mbar(a). The gas ballast is automatically switched and pre-and-post purge cycles are provided and controlled within the unit.

In contrast to ‘on-off’ control standards of other vacuum technologies, the GHS VSD+ machines feature a unique pressure set point control function that ensures the pumps maintain a constant reliable level of vacuum however variable the production demand.

The new installation has ticked all the boxes for Daryl Leivers and his company:

“ I am very impressed with the performance of the Atlas Copco pumps. Not only have they allowed us to achieve our production increase and maintain a constant vacuum level to ensure consistent product quality, they are also quieter, occupy a footprint that’s only the size of a pallet and, better still, provide the added bonus of a potential 60 per cent reduction in the energy demand for the process. ”

Daryl Leivers , Process Improvement Engineer at Ibstock Brick

He added that in comparison to the industry at large his company was always open to embrace innovative technology and in that regard, as well as in its customer service approach, “Atlas Copco was spot on.

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Editor's Notes:
Atlas Copco Compressors is the GB sales and service operation of the Atlas Copco Group providing oil-free and oil-injected stationary air compressors, gas and process compressors, vacuum pumps, turbo expanders, nitrogen generators, air treatment equipment (such as compressed air dryers, coolers, and filters) air management systems, and custom designed engineered packages.

Atlas Copco Compressors’ sales and distribution network means that specialist compressed air advice and service is always within easy reach. A team of over 80 service engineers operates across the country, to ensure maximum running efficiency and minimum downtime at its customers' sites.

In the United Kingdom, Atlas Copco also handles the sales and marketing of construction and mining equipment, portable compressors and electric power generators, industrial power tools and assembly systems – all backed up by a nationwide sales, distribution, service and maintenance network.

Atlas Copco is a world-leading provider of sustainable productivity solutions. The Group serves customers with innovative compressors, vacuum solutions and air treatment systems, construction and mining equipment, power tools and assembly systems. Atlas Copco develops products and services focused on productivity, energy efficiency, safety and ergonomics. The company was founded in 1873, is based in Stockholm, Sweden, and has a global reach spanning more than 180 countries. In 2016, Atlas Copco had revenues of BSEK 101 (BEUR 11) and about 45,000 employees. Learn more at www.atlascopco.co.uk/compressors.

For all of the latest news follow us on Twitter via @AtlasCopcoUKIRE, connect with us on Facebook and Google+ or find our Atlas Copco UK & Ireland LinkedIn company page.

For further editorial information contact Chris Butcher on 01582 390980.

For product or sales enquiries please contact 0800 181085.

For further company information contact Joanna Canton Long on 01442 222240.

Telephone number for publication: 0800 181085
E-mail address for publication: compressor.sales@uk.atlascopco.com
Website address for publication: www.atlascopco.co.uk/compressors

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