Modular Maintenance Services
With the Modular Maintenance contract, ANDRITZ works directly in a Process Area, Equipment Family, or Discipline (see below), with the aim of reducing maintenance problems towards zero.
Process Areas
- Woodyard
- Fiberline
- Recovery Island
- Utilities
- Paper Machine
- Tissue Machine
- Converting
Equipment Family
- Valves - Control valves and on-off valves
- Motors - Electrical motors
- Pumps
- Analysers - Liquid and gas analysers
Disciplines
- Reliability - Maintenance strategy & condition-based maintenance for mill assets
- Lubrication - Lubricants refill and analysis
- Predictive - Vibration, thermography and acoustics/MCSA (motor current signature analysis)
- Metrology - Calibration, ISO 9000 and 14000
- Automation - DCS, PLC, PIMs
- Mechanics – Dynamical and static
Case Study
A 1.5 million tons bleached hardwood kraft pulp mill in Brazil, was wrestling with high maintenance costs/ton and low mill availability. The aims were for ANDRITZ to make the maintenance more effective and to eliminate recurring problems that weren’t being solved by maintenance.
The work that ANDRITZ carried out at this mill is a great example of what would be included in a Modular Maintenance Services contract.
In this case, ANDRITZ identified some improvements that could be made to technical and management processes, and then implemented those improvements. One example of how the whole project worked was a white liquor vacuum pump/compressor unit that wasn’t working properly. As well as operating at reduced efficiency, the compressor had to be replaced up to 9 times a year, due to a high level of vibration and wear. Over 5 years, the unit had caused dozens of stoppages and production losses amounting to 300,000 Euros! And it was always for the same reasons, but the operations and maintenance teams couldn’t understand why vibration and temperature levels were too high and why their maintenance efforts didn’t prevent the repeated failures.
The company asked ANDRITZ to send in its failure analysis, maintenance and operation specialists, so they could diagnose the problem and solve it once and for all.
Predictive Techniques used:
- Vibration Monitoring
- Lubricant analysis
- Bearing temperature monitoring (off-line)
- Process cross information with predictive information
- Motor current monitoring (online)
- Root cause analysis
The analysis revealed that the main cause of the compressor failure was contaminated lubrication, due to using the wrong type of gasket, which was failing to seal out water effectively. Excessive load was also causing vibration in the compressor, which was wearing out the already-inefficient gasket even faster. Secondary causes included poor bearing housing seals.
After the vibration predictive technique revealed the failure, the compressor and the deficient parts were replaced – some with newly-manufactured parts.
The results include much-improved operational stability – the compressor is now only replaced every 2 years (instead of every 2 months) and has not failed since the work was carried out.
