Forming section field services identify potential problems

Forming section services provide important information about the potential or actual problems that may occur and their solutions. In addition, regular scheduled services ensure the reliable, safe and efficient operation of the forming section.

Vacuum system study

It has been shown that more than 50 percent of vacuum systems suffer from poor efficiency. In most cases, relatively simple improvements and inexpensive installations can significantly reduce energy consumption. Valmet's vacuum system study is a simple and efficient method for identifying potential improvements.

Benefits

• Better understanding of energy savings potential
• Better understanding of improved vacuum system controllability
• Feasibility of vacuum system modification

A machine's vacuum system accounts for 10–20 percent of its electricity consumption, which means 40–100 kWh/tpaper. By identifying and tapping into potential savings, the energy consumption of a vacuum system can be reduced by up to 30 percent. The graphic shows the electricity consumption of a newsprint machine vacuum system.

The study targets improvements in the energy efficiency and controllability of the vacuum system, and determines the feasibility of existing vacuum system modification. The study also provides you with capacity requirements for the main equipment, necessary new controls and an improved estimate of the energy savings potential.

Scope

An energy analysis starts with a desktop study and benchmarking that utilizes PI diagrams and information on the vacuum system's operating conditions. If this evaluation reveals any potential for energy savings, a more detailed vacuum system study with field measurements is recommended to identify specific necessary actions.

The vacuum system study includes:

• Mill visit by a Valmet specialist
• Kick-off meeting
• Machinery review
• Interviews with production staff
• Vacuum level and air flow measurements

Based on all the information gained, Valmet draws up a report including vacuum system capacity calculations and concept evaluations. The report provides you with recommendations presented in the existing PI diagrams, and investment cost estimates and payback times.

Forming section mechanical audit

Maintaining good forming section frame condition is important to provide for safe, reliable and high-quality operation of the paper machine. A key input for good maintenance is a thorough mechanical audit, which provides the condition of all the key components of the forming section.

Benefits

• Reduces risk of damage in the frame structure
• Reduces need for unplanned shutdowns
• Ensures high-quality operation
• Provides a foundation for future improvements

Reasons to conduct a mechanical audit on the forming section include:

• Safety: A damaged frame structure or roll connections may present a serious risk.
• Reliability: Rusted connections may cause unplanned shutdowns or additional damage due to roll falling on the wire.
• Quality: Structural integrity of the frames is important for the good operation of the forming section
• Improvements: Preliminary check of structures to provide a good base for planning improvements.

Scope

The audit includes a visual analysis consisting of:

• Frame condition (plate thickness measurement when required, addition of cantilevering beams)
• Frame fastening to base plate
• Roll fastenings
• Cleanliness of the machine
• Guides', stretchers' and doctors' wear and general condition

If the wire has been removed during the shutdown, additionally:

• Dewatering elements condition
• Roll surfaces

Valmet Breast Roll Shaker services

The breast roll shaker plays an important role in the quality and strength of paper and board. Valmet's shaker services – inspection and service – determine the current condition of the unit and ensure its reliable operation through good servicing.

Benefits

• Reduces unexpected shaker shutdowns
• Reduces operating costs
• Ensures the unit's long lifetime
• Improves paper/board quality

The breast roll shaker improves the quality and strength of low-quality pulp paper/board. It is therefore vital to keep the breast roll shaker in good condition to ensure the best possible operating profit. Valmet Breast Roll Shaker services include a thorough inspection of all related components with measurements, tests and visual inspections.

Scope

Shaker service actions performed at the mill site typically include:

• Operation inspection during production
• Inspections of transfer mechanism, carriage and hydraulic system operation
• Inspections/tests/changes/fixes of lubrication pipe and hose, slide rail wear monitoring and possible replacement, all sensors and alignment
• Wear parts replacement and status reporting

All worn wear parts are replaced during the service, while possible damaged parts are changed and recorded for further investigation. Works conducted and all findings from the unit are presented after the service on site, and a more detailed report is provided after the visit.

Inspection actions done at the mill site typically include:

• Operation inspection during production
• Inspections of transfer mechanism, carriage, hydraulic system operation, lubrication pipe and hose, all sensors and alignment
• Slide rail wear monitoring

Valmet's breast roll shaker inspection includes a thorough check of all related components with measurements, tests and visual inspections. All findings from the inspection are presented after the service on site, and a more detailed report with an analysis of the unit is provided after the visit.

It is recommended that the breast roll shaker service and inspection are performed alternately, with one happening each year. Service takes 2-3 days and inspection 1 day.

For more information about maintaining your forming section in peak operating condition, contact your Valmet representative.