BRUSSELS, Nov 1, 2014 (PPI Magazine) - With increasing competition in the pulp and paper industry, manufacturers are continually looking to make efficiency and productivity improvements - including making the most of a workforce that is often smaller than in the past.
Over the past 10 years, wireless technology has become well established within the process industries, helping to reduce the cost of installing additional monitoring points within plants and mills, speed up such installations, and enable data to be recovered from remote and stranded locations. This additional data has helped companies to improve safety, reduce environmental impact and optimize performance. Now, with the availability of mobile worker technology, wireless technology is empowering workers with real-time process and equipment data - no matter where they are located within the mill.
Access to this real-time data presents an opportunity to make a real sea change to workers' day-to-day practices. Within process industries such as pulp and paper, the traditional approach has been to have a centrally located control room that oversees specific processes or indeed the entire mill. An operator, or team of operators, is stationed in front of operator screens and performs a range of monitoring and control tasks, reacting to alerts and alarms, running tests and doing routine procedures. Control room operators are supported by staff stationed on the mill floor. These workers perform tasks including cleaning and maintaining equipment, making adjustments, handling jams and supporting tests and production starts/stops.
In general, this ‘dual' operation works well as there is constant monitoring of the process whilst these routine mill floor tasks are performed.
However, the limitations of this approach become apparent when there is only one operator available to handle both elements. If a single operator is positioned in the control room, perhaps during a night shift, that person is unable to leave the control room to perform the tasks on the mill floor, because doing so would risk missing an alert or be unable to respond to an important incident. Operators become tied to the control room, which doesn't maximize their capabilities, is inefficient and doesn't present workers with a high degree of job satisfaction.
Mobile worker technology
Mobile worker solutions can dramatically improve productivity and efficiency by using wireless technology to give operators instant access to data from the control/automation system, maintenance data, and operation procedures - wherever they are in the mill.
Mobile worker technology brings the control room to a handheld device such as a laptop or tablet. It provides the opportunity for operators previously tied to the control room to have the flexibility to go into the field and perform required tasks, while maintaining full access to the functionality of the control system.
The Stora Enso plant in Ghent, Belgium, produces more than 500,000 tonnes/yr of newsprint and magazine paper from 100% recycled paper. The facility is monitored and controlled from a central control room by operators who also have other tasks to perform. These tasks include cleaning equipment, inputting data to the SAP manufacturing execution system when specific things happen in the process, and writing a daily report. These additional tasks will vary depending on how the processes have run during that working day.
(With real-time information available from the control system, operators can now resolve problems much faster)
During the night, operators are required to perform fixed rounds in the field. Their tasks include visually inspecting the installation, checking the valves for emissions, checking pumps and motors for excessive noise caused by vibration that might indicate a problem, and monitoring and recording tank levels. During these rounds the operators need to have continuous access to process alarms and alerts so they can investigate problems and take action -- for example, by stopping a sequence or shutting a valve.
Putting wireless technology to work
Stora Enso is continually seeking opportunities to operate more efficiently, reduce costs and stay competitive. As the company was in the process of upgrading the DeltaVTM distributed control system for the deinking section of the mill, it turned to Emerson to see how the latest wireless technologies could help improve operator efficiencies.
Emerson recommended a wireless network and mobile worker technology. This would enable operators to carry out their rounds while using a hand-held device to monitor mill status information sent from the control room. This remote access to process information means they can deal with alarms and alerts as they occur while they move around the mill carrying out their regular duties.
Stora Enso put the technology to work in the deinking section, where Emerson installed a Wi-Fi network to provide "hot spot" access. Operators access the network using `ruggedized' Apple iPad4 tablets with Emerson's DeltaV Remote Operator Station application. The mill chose iPads because they were easy to handle and quick to replace should they be damaged. The wireless network is secured using AES 128-bit encryption and its integrity is continuously monitored. Alerts are sent to the administrators if degradation of the wireless signal is detected.
The wireless network consists of 10 industrial access points, a wireless LAN controller and a network management application to provide indoor and outdoor coverage for the two floors of the deinking section. A managed switch connects the wireless network with the existing wired network. A wireless LAN controller handles network-wide wireless functions such as security policies, quality of service and mobility.
(Operators can move freely around the mill to perform a range of tasks while keeping a close eye on overall performance)
With real-time information available from the control system, operators can now resolve problems much faster. The mobile worker application also allows the mill to record observations directly into the system and avoid transcription errors. It can also independently perform process procedures and initiate or execute work orders while in the actual process area. Being able to perform multiple jobs in one operator round and saving trips between the control room and our process units has helped to improve the productivity of the operators.
Wireless technology powering mobile workers is enabling operators to carry out tasks that would normally require two people. Operators can move freely about the mill to perform a range of tasks while maintaining full access to features and functionality they would have if they were sitting in the control room itself. Should an alert take place whilst the operator is on the mill floor they would be able to respond immediately. Should an adjustment be needed it can be performed using the iPad and Remote Operator Station application right on the spot. There's no need to go back into the control room or relay instructions to a second person. By multi-tasking, it is possible to increase the efficiency and productivity of each operator.
Extending productivity gains
The increased operational efficiency has helped to reduce operational expenditure, and the return on investment has taken less than six months. The wireless network makes it easy for Langerbrugge to add new mobile worker devices and other wireless applications as and when they are required.
Mobile worker technology has enabled mill operators to combine tasks and react much faster to potential problems. Workers have the ability to move freely around the mill and perform multiple tasks, providing much more variety to their work schedules. This helps to motivate workers resulting in further gains in productivity.
Wim Schauvliege is project engineer, Stora Enso Langerbrugge, Ghent, Belgium.
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