A transparent view of emulsifiers

Although wood pulp and/or recycled paper provides the raw material for most papermaking, there is a variety of chemicals that are used as additives to control paper properties such as water absorbency. These additives are generally prepared on site as emulsions for adding to the paper stock.

This preparation process is carried out in specially engineered emulsification units, such as those supplied by Bradford-based Northern Pumps to Raisio Chemicals, a global supplier of chemicals to the pulp and paper industry.

Raisio has operations all over the world, close to the paper mills themselves, and wanted a way of supporting and maintaining its on-site equipment without too many call-outs over long distances. Already in the process of upgrading its emulsification units to be controlled by Schneider Electric PLCs and aware of that company's 'Transparent Factory' web module, Northern Pumps suggested that Raisio could connect all the units to the Internet to collect data centrally, which could then be monitored via a web site.

'Raisio was enthusiastic,' says James Jordan, Northern Pumps' electrical design manager, 'and asked us to put a system together. We decided that all the machines should have GSM modems that could call back to a Schneider Modicon TSX Premium PLC in our offices in Bradford. The modems would transfer data, which the PLC would store and be accessible through an ordinary web browser on the Internet.'

Now, each emulsification unit is controlled by a Modicon TSX Micro PLC, with a Magelis HMI (human machine interface) for local operators. In the communications slot of the PLC there is a cellular modem, which connects over GSM to the Premium PLC in Bradford. Data is sent back through this link, which also allows the machines to be monitored remotely.

The web module comes with the Premium PLC and, using a leased line, is connected to the Internet all the time. With the correct user name and password, engineers anywhere around the world can now look at web pages with the Raisio domain name and access information about each machine.

'This remote monitoring has been piggy-backed on top of the individual control systems in different countries,' says Jordan. 'We monitor systems around the world, in Britain, Europe and the Far East. If there is no GSM available locally we can use a land line, as in Korea. The basic principle is the same for them all - for every new system added to the network we write a web page and as soon as the telemetry is in place and working, people in that country can see their machine using a web browser, without the need for any special software or configuration.'

The customer's point of view is given by Raisio Chemicals' Marc Collinson, who says: 'I am responsible for emulsification machines located in Europe and the Far East. With the information available on the Internet I can watch the units run and see alarms from my home. If required, I can arrange local engineers to fix faults or carry out maintenance remotely, which certainly saves our company money on travel.'

The remote monitoring system has proved to be very effective. Emulsification units often run continuously for long periods, and there have been situations where a mill has been told of a potential fault before the local operators had even experienced a problem. At other times, when a customer has questioned the process during papermaking problems, it has been possible to examine machine logs and eliminate equipment issues from the equation.

Colin Jackson, also of Raisio, says: 'As I can see the units on the web remotely, I have been able to contact our customers, warning them of an impending alarm or out-of-specification emulsion which could have the potential to stop the paper machine, causing a unit shutdown. This obviously prevents machine downtime, which is a big bonus from our customers' point of view.'