Paperweek International 2003: Commissioning Can Be Hard but It’s Worth the Effort
March 1, 2003 By Pulp & Paper Canada
There’s nothing quite like the feeling of starting up a machine after a successful upgrade; it’s like having a new toy, or at least an old one with a fresh coat of paint. However, before the day of th…
There’s nothing quite like the feeling of starting up a machine after a successful upgrade; it’s like having a new toy, or at least an old one with a fresh coat of paint. However, before the day of the great switch-on arrives, there’s a lot of work and organization, often in difficult circumstances, which must come together.
During the session on electrical engineering, Roger McCuaig, senior project engineer with Wood, Banani & Associates Ltd., presented a paper on the commissioning process for a paper machine upgrade project. “Commissioning,” he began “can be described as the set of activities undertaken in order to ensure that all systems and equipment covered by the project mandate are verified and made ready for start-up.”
As anyone who has been in such a situation will attest, commissioning is the key to the success of any major construction project. Machine downtime is expensive and this negative cost factor is often further exacerbated by hordes of construction workers, servicemen, consultants and engineers.
For large projects, the most widely used application is commissioning by system which enables a project to be broken down into manageable chunks. On the project described by McQuaig, the commissioning activities were divided into areas:
An installation check to enable personnel to get to know the equipment and seek out possible operations and maintenance problems.
A wiring check is undertaken and PLC and DCS cabinets are verified to prevent equipment damage.
Device checks are undertaken, manually if necessary, to ensure they work.
Software and configuration is checked.
All piping and reservoirs is flushed, cleaned and inspected.
As each system is completed it is then turned over to the commissioning team for operational checkout. Any deficiencies are logged and submitted to the project manager, who in this case was an out-sourced professional.
Here, McCuaig added a cautionary note. “What constitutes a deficiency must be clearly defined,” he said, as this, in his opinion, can often be a confusing issue. Preparation time is also very important.
“I arrived on site three weeks before machine shutdown,” recalled McCuaig. Progress of the project was logged by a tagging system. Construction completed items were highlighted in yellow, signifying they were ready to be checked. When it was completely signed off, it was green tagged and highlighted in green in the system book, the principle tool for logging activities. Progress reporting was undertaken every two to three days during the first week, and then every day during the final, second week of shutdown. At the beginning of the project, McCuaig reported slow progress due mainly to limited amount of equipment being ready for commissioning. However, this gradually improved, although mill electricians and technicians had been scheduled for night shifts toward the end of the procedure as a precautionary measure.
In the end, McCuaig said that as with any project some things went well, whilst other areas offered problems. “I was really happy about the presence of a field coordinator for the ABB drives commissioning team,” said McCuaig. Another positive element was the appearance of the electrical contract manager at commissioning meetings. On the downside, the deficiency list caused problems and piping, mechanical and civil inspectors were not integrated into the commissioning team as well as had been hoped.
Before McCuaig’s presentation, Ed Miles, a consultant with Ro-Ball services had offered the assembled an insight into electrical damage in rolling element bearings due to variable speed drives, and other sources. Miles said that the most common electrical damage encountered in bearings is a fluting pattern, which is usually related to an AC power supply source. Other sources of damage are fusion craters and electrical discharge erosion. Miles went on to say that there are two ways to overcome these electrical passage problems. Firstly, is the use of bearings which are produced with a ceramic coating, and secondly, by utilizing a ceramic coating on the outside diameter and side faces of the outer ring
However there are, Miles said still many unanswered questions and he urged mill owners for their help.
“When you replace bearings, don’t throw them away, send them back,” suggested Miles. “They have a story to tell and we want to get a database going.”#text2#
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