Minimum downtime and maximum efficiency - PrimeService for air and energy systems for paper machines

It seems obvious that maintaining equipment is the best way to maximize efficiency of tissue, paper and board machines, however what is not clearly known is just how much difference good service plans make; analysis confirms that regular scheduled maintenance reduces downtimes by as much as 75% when applied to paper and tissue machines and processes. 

“It’s all about the critical components,” explains Riccardo Pierini, Customer Care Manager, ANDRITZ Novimpianti. “With our decades of extensive experience and knowledge we know exactly how, when and what parts in our technology and systems need to be regularly maintained, as well as optimized for maximum efficiency.

“A 75% reduction in downtime is absolutely possible as with our extensive knowledge, we are well aware of the lifetimes of all components. With the correct maintenance of these components we have proved that they can operate to the guaranteed lifetime, and often go well beyond.” 

Pierini refers to ANDRITZ Novimpianti’s 30 years’ experience of designing, installing and servicing drying technology for all kinds of paper and board, MG, and tissue installations around the world. The company provides the industry with specialist equipment including hoods, steam and condensate systems, heat recovery units, mist elimination and ventilation systems for new machines, rebuilds and upgrades.

DIFFERING APPROACHES TO MAINTENANCE AND SERVICE    

Pierini says that there are different approaches to maintenance depending on the customer, “We find that corporate companies, the ones who have been operating for some time and have skilled owners, know the importance of scheduled maintenance. On the other hand, we also have customers that would prefer to risk waiting until their machines breakdown and then call on us to fix them.

“This is how we can clearly see that those companies operating with a scheduled maintenance program have a higher uptime of usually more than 75% when compared to those companies that operate without one.”

However this is not just about downtimes and uptimes, in a world where energy prices have gone off the scale, it has forced paper and tissue producers to have a very close look at how savings can be made in all areas of production.

“We now have a lot of customers asking us for advice on OEE (Overall Equipment Efficiency) to maximize their usage of energy. And this is one of the main advantages of scheduled maintenance as this will not only reduce downtime due to breakdowns, but it also maximizes machine production efficiency and energy management.“

“Scheduled maintenance is key for reaching the absolute OEE of all components in paper and tissue systems and technology, and well-maintained tissue plant can ensure an OEE of 90-95%.”

Another aspect Pierini stresses the importance of is safety, “Number one on the list at ANDRITZ is of course safety as this also not only protects the operators, but it also results in more uptime as accidents stop production and lead to overall inefficiency. We encourage all our customers to also make safety their first priority.” 

SCHEDULED MAINTENANCE: COVERING 360 DEGREES OF THE PLANT

ANDRITZ supplies complete, across-the-board maintenance and servicing on tissue, paper and board machines, from stock preparation to reel. This service offering basically covers everything paper producers need for running a fully efficient operation. The service areas covered include all aspects and components of stock preparation (for example refiners, deflakers, pumps), headboxes, Yankees, shoe presses, steam and condensate systems, energy recovery as well as dust and mist removal systems, hood and air systems and ambient conditioning ... and many others.  

“We like to think of ourselves as covering the 360 degrees of the tissue plant,” says Pierini. “Mostly we can supply any parts and service for all OEMs, not just ANDRITZ, including for the headbox, Yankees and hoods.”

Scheduled maintenance packages are designed by ANDRITZ after close collaboration with the customer, detailing what systems and components need to be regularly serviced. Pierini explains, “Along with the customer’s technical department we establish a servicing frequency and prepare an outline of the machine condition requirements that will allow servicing the individual components. After this collaboration we draw up and offer and quotation for the services needed.” 

MAINTENANCE WITH THE LEAST DISRUPTION  

Scheduled maintenance needs to take place with as little disruption as possible, ideally when there is a complete machine shutdown during an annual stop. Most mills, for instance in Europe and the US, have two stops a year, one in the summer and another at the end of the year.   

“For scheduled maintenance to take place the paper or tissue machine needs to stop and cool down to enable our dedicated service personnel to get under the hood and check all the internals,” explains Pierini. “Due to the high temperatures in the hood, in a big one, this can take up to one day to cool down, however there is a lot of other maintenance work on critical components and auxiliary equipment that can be carried out during that shutdown period.”

Maintenance is performed following a checklist of inspections to be carried out which is filled in at each service intervention. In addition a final report is provided to the customer that contains all the results and respective recommendations for machine optimization. Subsequently follow up meetings are scheduled with the customer to set a date for the next inspection.

ANDRITZ has numerous examples of where scheduled maintenance has enabled customers to avoid unplanned shutdowns, including one at a big corporate company close to Lucca. Pierini says, “The customer in this case had signed and annual contract for regular inspections of the hood on the hood burners on one of their tissue machines. During one of the shutdowns it was noticed that the spring on and off switch was not perfectly intact. We promptly replaced the component to avoid the possibility of it breaking during machine operation thereby avoiding the system from operation at its full potential.” 

IN CASE OF EMERGENCY

In all industrial processes, even with scheduled maintenance, unplanned problems and events will and do occur. We have skilled people covering all eventualities at is service centers who are dedicated to keep paper and tissue machines and processes running with advice and quickly accessed spare parts.  

“We run our spare parts division on a just-in-time basis, however as we are aware of the critical components that are needed to avoid a complete breakdown, we always have more than we need in stock,” says Pierini. “We update our spare parts every two months to ensure we always have a supply of the most critical components.”

“When it comes to breakdowns, we first try our best to solve the problem remotely, adds Pierini.  “In fact a lot of breakdowns now are caused by software problems, 95% of which we can solve remotely. And when it comes to a mechanical breakdown, often the mill has skilled personnel with a lot of experience in keeping the machine running, here again we provide remote assistance, and we are able to send an engineer any time needed.”

“We are well aware of the pressure our customers are under when it comes to keeping their machines running,” says Pierini. “We have a target of getting back to the customer in no more than four hours when a request comes through, and we do our level best to solve any problems the customer has online there and then. If it’s a more demanding problem that we can’t solve online, we do our best to get an offer and quotation out to them within 2-3 days, and never more than five days. Based on the urgency, and in agreement with the customer, we can send to him a skilled engineer/technician immediately”.

FLEXIBLE MAINTENANCE PACKAGES, INSTRUMENTATION, AUDITS AND SURVEYS  

At ANDRITZ Novimpianti, for example, we provide an array of dedicated packages for scheduled maintenance programs, including for burners, steel and cast-iron Yankees (internal and external), complete steam systems for paper machines, as well as for dust and mist removal systems and hall ventilation.

“We have complete flexibility in the scheduled maintenance packages we provide,” says Pierini, “From small to medium to large, it really depends on the customer and their needs. For example we provide a burner maintenance check package over the space of three years, where the customer can have the checks done whenever they need it, for instance two in the first year and one later in the third year. We have proved time and again that service packages make sense, and save our customers money.”

ANDRITZ Novimpianti has also invested highly in instrumentation for crucial data management, which is constantly calibrated and certified. Instrumentation utilized includes: exhaust gas analyzers to measure CO, NO_x etc., laser thermometers, thermographic cameras, temperature and humidity meters, pressure gauges and vibration and flow meters. The instrumentation portfolio ANDRITZ Novimpianti is employed to carry out specialized audits, including the Survey Green Paper which seeks to identify and isolate any deficiencies or energy losses being incurred on tissue, or paper and board machines.