Online unit halts trouble at mill
27 Mar 2007
Mondi Business Papers has significantly reduced the number of unplanned shutdowns at its Richards Bay Mill in South Africa, thanks to the installation of a CSI 4500 Machinery Health Monitor from Emerson Process Management. The online system detects changes in fan behaviour, alerting operators and prompting a remedial response that prevents unexpected fan failures and associated boiler shutdown.
Uneven build-up of deposits on the runners of fans providing air to the mill's recovery boilers changed the balance of the fans, causing numerous problems. Bearing failure on the primary and secondary air fans could result in a shutdown of the recovery boilers for at least six to eight hours. The cost of the recovery boiler being down is approximately Euro13,562 per hour, not including the cost of repairing damaged equipment.
"In just seven months, Emerson's Machinery Health technologies have prevented seven incidents due to fan imbalance and early bearing defects that could have shut us down," said Nico Groenewald, senior mechanical technician, condition monitoring. "We estimate that the savings in lost revenue from these incidents would have been Euro424,539. Not only are we more productive, but this is a safer workplace."
The online system is designed to provide a continuous flow of information on the condition of the fans, so that operators are immediately aware of any changes. Any faulty fan can then be shut down for cleaning or repairs before failure occurs.
Previously, fans were monitored as part of a routine vibration monitoring programme. This meant that any sudden changes in vibration levels might go undetected for several days, or until the next scheduled measurement.
According to Emerson, an additional benefit of the monitoring system is the ability to trend fan behaviour over time. This, it said, enables the condition of assets to be monitored remotely.
In addition to early detection of bearing problems and misalignment leading to failure, knowledge of vibration behaviour over time can also be used as a quality control factor after maintenance interventions.
Western Europe's largest wastewater treatment plant, the new Brussels-North sewage plant serving over a million people in Belgium, is due to go 'on-stream' this month, partly with the help of seven giant expansion joints.
The 2.7m by 2.5m expansion joints are fitted in concrete ducts handling the airflow of 10m/sec at 140°C and 1.2bar needed for biological treatment of sewage. The units were custom-made by UK based James Walker Townson (JWT) from 9.5mm-thick EPDM rubber reinforced with three layers of aramid fibre.
JWT's remit covered the principal design and supply of the frames and compensators and the construction of the stainless steel frames for all seven joints. James Walker Benelux was responsible for the gaskets.
The expansion joints were tested by JWT and witnessed by Lloyds in order to comply with the Pressure Equipment Directive Category 2 to ensure safety at the required pressure and airflow. The company also applied finite element analysis to ensure frame design integrity at the working conditions stated.
Lakeland Dairies Co-operative Society, based in Kileshandra, the Republic of Ireland, has trebled the amount of solids that can be removed from the plant every day by installing a new decanter centrifuge.
The Centrifuge CQ5000 from Centriquip replaced a 30-year-old wastewater facility at the plant. The new unit can put through 45 cubic metres per hour of sludge from the settling tanks, said Rory Farrell, environmental manager for Lakeland Dairies. "That's three times the capacity of the old system."
The wastewater generated at Lakeland Dairies is mostly as a result of the CIP (Cleaning in Place) system used to wash processing equipment. Lakeland uses two settling tanks to settle sludge as part of its wastewater treatment process.
The CQ5000 draws its feed from the bottom of these tanks and from two sludge-thickening tanks. The unit separates clean water for return to the water treatment plant from the solid matter, which is used on land as a fertiliser.
Uneven build-up of deposits on the runners of fans providing air to the mill's recovery boilers changed the balance of the fans, causing numerous problems. Bearing failure on the primary and secondary air fans could result in a shutdown of the recovery boilers for at least six to eight hours. The cost of the recovery boiler being down is approximately Euro13,562 per hour, not including the cost of repairing damaged equipment.
"In just seven months, Emerson's Machinery Health technologies have prevented seven incidents due to fan imbalance and early bearing defects that could have shut us down," said Nico Groenewald, senior mechanical technician, condition monitoring. "We estimate that the savings in lost revenue from these incidents would have been Euro424,539. Not only are we more productive, but this is a safer workplace."
The online system is designed to provide a continuous flow of information on the condition of the fans, so that operators are immediately aware of any changes. Any faulty fan can then be shut down for cleaning or repairs before failure occurs.
Previously, fans were monitored as part of a routine vibration monitoring programme. This meant that any sudden changes in vibration levels might go undetected for several days, or until the next scheduled measurement.
According to Emerson, an additional benefit of the monitoring system is the ability to trend fan behaviour over time. This, it said, enables the condition of assets to be monitored remotely.
In addition to early detection of bearing problems and misalignment leading to failure, knowledge of vibration behaviour over time can also be used as a quality control factor after maintenance interventions.
Western Europe's largest wastewater treatment plant, the new Brussels-North sewage plant serving over a million people in Belgium, is due to go 'on-stream' this month, partly with the help of seven giant expansion joints.
The 2.7m by 2.5m expansion joints are fitted in concrete ducts handling the airflow of 10m/sec at 140°C and 1.2bar needed for biological treatment of sewage. The units were custom-made by UK based James Walker Townson (JWT) from 9.5mm-thick EPDM rubber reinforced with three layers of aramid fibre.
JWT's remit covered the principal design and supply of the frames and compensators and the construction of the stainless steel frames for all seven joints. James Walker Benelux was responsible for the gaskets.
The expansion joints were tested by JWT and witnessed by Lloyds in order to comply with the Pressure Equipment Directive Category 2 to ensure safety at the required pressure and airflow. The company also applied finite element analysis to ensure frame design integrity at the working conditions stated.
Lakeland Dairies Co-operative Society, based in Kileshandra, the Republic of Ireland, has trebled the amount of solids that can be removed from the plant every day by installing a new decanter centrifuge.
The Centrifuge CQ5000 from Centriquip replaced a 30-year-old wastewater facility at the plant. The new unit can put through 45 cubic metres per hour of sludge from the settling tanks, said Rory Farrell, environmental manager for Lakeland Dairies. "That's three times the capacity of the old system."
The wastewater generated at Lakeland Dairies is mostly as a result of the CIP (Cleaning in Place) system used to wash processing equipment. Lakeland uses two settling tanks to settle sludge as part of its wastewater treatment process.
The CQ5000 draws its feed from the bottom of these tanks and from two sludge-thickening tanks. The unit separates clean water for return to the water treatment plant from the solid matter, which is used on land as a fertiliser.
