Installed in 1997 by Schlick who have since been acquired by Wheelabrator Group, the HB 10/12 machine was still completing its cleaning task very well, but was no longer state-of-the-art in terms of ergonomics and ease of maintenance.

At the end of 2013, the team around Herbert Jarosch, Head of Bulk Water Meters at Diehl Metering, started a comprehensive machine audit to decide whether to replace the machine with a new one or upgrade it.

The machine’s track-record of achieving consistent and high production quality throughout its time of service, led Mr Jarosch to go for an upgrade instead of a new machine: “The equipment was so well integrated into our processes and was still doing such an excellent job that we wanted to keep it in situ, but a range of upgrades were necessary to improve workflow and reduce maintenance requirements and use of resources."

A more ergonomical workflow, as well as technical improvements of the existing system were key elements of the equipment modernisation programme (“EMP“) planned and carried out by Wheelabrator Plus throughout 2014.

Going ergonomical

Detailed examinations and analysis on site helped to quickly identify weak spots in terms of handling around the blast machine. Manual operation of the machine, in particular the lifting of heavy castings onto hooks and the subsequent manual pushing of the loaded hanger into the machine, were strenuous for operating staff. Furthermore, some of the upper hooks of a hanger could only be reached by lifting the workpiece over head.

The machine was therefore equipped with automatic hanger transport units with horizontal and vertical range, allowing operators to halt the hangers in any position required for easy loading.

This measure alone drastically improved working conditions, but it also enabled a faster loading process, creating headroom for production increases.

Free of faults and niggles

The frequency of faults as well as maintenance intervals were identified as further areas of improvement, with the machine control and exhaust air repeatedly causing problems. Used air in the initial machine set-up still contained solid particles that were battering the filter cartridges, causing excessive wear and high maintenance costs.

An abrasive cleaning and separation system solved the problem, as it reliably removed shot particles from the exhaust air, considerably increasing the life span of filter cartridges.

The initial machine control had also been a frequent source of faults, putting production at risk. It was replaced by an extended control (SPS), which can accommodate the added complexity of the machine (ie, controlled the hanger transport units).

As part of the programme, the Wheelabrator Plus team also upgraded drive and transmission of the bucket conveyor and installed a hanger spinning system for more even and consistent blast results.

Machine evolution

The strategic modernisation of an existing (and trusted) blast machine allowed Diehl Metering to meet changed requirements without having to invest in a completely new machine. In terms of ergonomics, the ‘new’ old machine is unrecognisable. Automatic hanger transport and improved loading have made life a lot easier for machine operators.

Taken as a whole, the improvements implemented by Wheelabrator Plus had a positive overall effect on workflow efficiency around the blast machine. Maintenance intervals, wear and machine downtime have all been reduced.

Robert Mult, Technical Sales at Wheelabrator Plus, visits Diehl every six months to check in on the machine and stays in ongoing dialogue with the team around Mr Jarosch. He summarises: “Purchasing a new machine is not just a matter of cost, it usually also means greater disruptions to production. A well-oiled existing blast machine set-up is worth a lot and there are so many things we can do to bring it up to speed. On the basis of an existing machine, we can create one that is as good as new and can meet completely new requirements. The example of Diehl Metering shows all the facets an equipment upgrade can cover – from ergonomics to remodelling of the blast process for new workpiece types."

The equipment modernisation programme at Diehl Metering concluded in March 2015. Since then, the HB 10/12 has been blasting reliably, while being kinder to operators and demanding less attention from maintenance teams – despite an increase in production of up to 15%.