Brick Production System Upgrade Pays off for Wienerberger

13 July, 2020

First published in the July 2020 issue of Quarry Management as Brick Manufacturing Makeover

New Atlas Copco compressed-air and vacuum system delivers energy savings and reduction in downtime

An Atlas Copco compressed-air and vacuum system upgrade for Manchester-based brick manufacturers Wienerberger Ltd is resulting in significant savings in energy costs, estimated to be around £38,000 per annum, along with reduced CO2 emissions and production downtime, and the added benefit of a short-term payback.

The company’s Denton plant, near Manchester – one of 14 Wienerberger production sites in the UK providing wall, roof and landscaping products – is a major part of global building solutions manufacturer Wienerberger Building Solutions, the world’s largest producer of bricks and clay blocks and the market leader for clay roof tiles.

The upgrade project at the Windmill Lane factory was triggered by episodes of unreliability with the existing compressor system. These had led to a stark choice between carrying out costly motor rewinds or taking a longer-term view and replacing the compressors with state-of-the-art alternatives offering greater efficiency and more dependable performance.

The compressor installation’s primary function in the brick production process is the provision of a 7-bar air supply to pneumatic cylinders powering the clutches of the mixers that blend essential additives with the basic ground and milled clay processing operation, and those of the extruders. This, together with the final sandblast treatment, determines the quality, performance and appearance of the finished brick products.

Similar performance and efficiency issues were experienced with the existing vacuum pump system employed to remove air from the brick material before extrusion, forming and kiln firing. Operation was intermittent because of problems running cooling water through the pumps, whose design offered only limited opportunity for corrective maintenance.

To rectify these problem areas of the manufacturing processes, Wienerberger’s director of production North, Miles Coppinger, called on the services of Atlas Copco, specialist suppliers of both compressed-air and vacuum systems. His decision was based on familiarity with the company’s products, service and reputation from experience in a previous organization.

The first task consisted of a week-long iiTrak data-logging procedure to determine the energy usage of the existing plant, the air demand requirements, and the system’s capabilities in order to establish a flow profile. The results demonstrated a clear opportunity to make significant energy savings, reduce the company’s carbon footprint and introduce a new level of reliability and performance.

The recommendation was for a complete replacement compressed-air installation comprising an Atlas Copco GA90VSD+FF rotary screw compressor, a fixed-speed GA75+ machine, together with an FX15 refrigerant dryer, a 3,000-litre air receiver with electronic zero-loss drain, plus ancillaries including an OSC oil/water separator, all connected by an Optimizer 4.0 central controller.

To minimize pressure drops in the air network, the existing 4in galvanized pipework was to be replaced with an Atlas Copco AirNet 80mm modular aluminium system, installed by local premier distributors Pennine Pneumatic Services. To contribute to overall energy efficiency, the compressors would feature winter/summer ducting to aid heat recovery and direct hot air into the factory during colder months via manual vent switching.

The Denton plant had previously used liquid ring vacuum technology for clay extrusion but required a more efficient solution that would also allow elimination of the risk of Legionella from the cooling towers used to support the existing liquid ring pumps.

The new vacuum system needed to be suitable for the high water content and high ambient temperatures involved in Wienerberger’s clay extrusion application. Based on the substantial energy-saving potential and the option to remove the cooling requirement, Wienerberger chose the Atlas Copco GHS585 VSD+ Humid oil-sealed rotary screw vacuum pump to meet the site’s requirements.

The smart features of the Atlas Copco GHS585 VSD+ allow Wienerberger to link directly into the application’s PLC system, providing direct control of the pump when the production line is running. This allows them to benefit from energy savings due to the set point control feature of the vacuum pump, which optimizes the process and provides maximum energy efficiency by ensuring that only the vacuum required is generated.

It has now become Wienerberger’s parent company’s policy to switch from liquid ring vacuum pumps to rotary screw vacuum pumps in all its production plants.

The entire upgrade was carried out to a three-phase installation operation which included solving an accommodation problem with regard to siting the new equipment. In the first phase, the GA75+ compressor and FX dryer back-up units were installed in the plant’s bike store, which was eventually relocated in the old compressor house from which the original units were removed.

The second phase saw the new main-duty compressor system equipment installed and commissioned before completion of the final phase, involving removal of the redundant units and the installation of ducting.

At the same time, the central control and monitoring system was linked to the newly installed Atlas Copco GHS VSD+ oil-sealed and air-cooled rotary-screw vacuum pump, which solved the company’s air-extraction reliability issue.

The net result of this major makeover project, in terms of system savings and a potential payback within only two years, is good news for Miles Coppinger, who remarked: ‘The estimated energy saving from the first two phases is in the region of £38,000 per year. By replacing the old equipment, we avoided the cost of overhauls, which would have amounted to at least another £30,000.

‘Naturally, I will be keeping a sharp eye on continuing performance and will be establishing data from sensors both in terms of kW/h/m3 air power costs, but also as power related to the total volume of product output for any given period.’

He added that he valued the technical support and efficient way in which the project was conducted by Atlas Copco, as well as the peace of mind that a Total Responsibility service plan offered: ‘I am happy to work with them and pleased to report that Wienerberger have signed a blanket agreement to make Atlas Copco a preferred supplier in the UK.’

An additional benefit derived from the new installation is that Wienerberger have reduced their carbon footprint by almost 200,000kg per annum.

Moreover, the company is safe in the knowledge that key components of the system are proven top-performing, energy-reducing products. These are the NEOS inverter in the GA VSD+ compressor and the Optimizer 4.0 master controller. Both are included in the Carbon Trust’s Energy Technology List, which carries entitlement for businesses that purchase these technologies to accelerated tax relief on their profits.