When it comes to process optimization, is the Swedish company Alfa Laval known worldwide. The Global Player offers machines and equipment in the areas of separation, heat transfer and fluid handling. A portion of the solid-liquid separation by decanter centrifuges. A VK type vibration sensor by IFM Electronic here permanently monitors the overall state of vibration and protects against equipment failure.
Decanter centrifuges, also briefly called decanter, serve to separate interspersed with solids liquids. The separation is performed in a horizontal cylindrical barrel with a feed screw. The medium to be separated is passed through a stationary inlet pipe into the drum and slowly accelerated by an inlet manifold. Due to the centrifugal force, the solids are deposited on the drum wall. Screw and drum rotate in the same direction, but with slightly different speed. Characterized the solids are transported, compressed, and output to the tapered end of the drum. The clarified liquid on the other hand runs on adjustable overflow weirs into the chassis.
Typical applications are found in wastewater treatment where decanter sludge separated into solids and liquid. But also in the food industry, for example in the manufacture of fruit juice, fruit and vegetable processing, cheese making and in breweries decanters are often used.
Have one thing in centrifuges, regardless of size, in common: Due to the high speeds, even the smallest irregularities in the distribution of weight cause high unbalanced forces acting on the bearings and the drive. The consequences are unplanned machine failure and severe secondary damage in the worst case.
Machine protection around the clockEven if the components are designed for high loads, mechanical loads, moisture and natural wear live off the material, especially on the bearings and the gearbox. Often the machines are working around the clock in continuous operation. Regular maintenance is required to avoid unplanned outages.
Alfa Laval focuses on additional safety: An electronic vibration monitoring to detect early changes of machine vibration to avoid serious damages and to plan the repair action.
The Swedish company first started out with our own developments for machine diagnosis. But in order to cover the complexity and range of innovations, the development team headed by Peter Blomberg, Automation Manager, the core automation teams decided at Alfa Laval for collaboration with IFM Electronic GmbH, the world leader with decades of experience in sensor and automation technology.
In addition to all kinds of industrial grade sensors, the Essen-based company also offers Systems for vibration monitoring of. While the compact vibration monitor VK series are perfect for the decanter centrifuge from Alfa Laval. They are simply screwed into the housing of the centrifuge. Over a mechanical adjusting ring for the shift point is set. If the vibrations exceed this specified limit, the controller is alerted by switching signal. In addition, the sensors provide a signal proportional to the vibrations of the analog signal to the controller. This allows a permanent monitoring and early detection of irregularities in the vibrational behavior of the machine.
"Before we install new systems, we conduct extensive tests to meet the high quality requirements. The use of the vibration sensors from IFM is running perfectly, "said Blomberg pleased with the result.
Vibration diagnosis in detailThe electronic vibration monitor VK type permanently monitors the overall vibration condition of machines and systems according to DIN ISO 10816. The sensor measures the rms vibration velocity at a non-rotating component surface. When an adjustable limit value is exceeded, the device via a switching contact on alarm. In addition, the characteristic value is output as a current signal (4. .. 20 mA) for connection to the process control system.
The simple operation via 2 radial setting rings allows quick adjustment of the switching point and the response delay. For tampering an optional cap provides. The monitoring of overall vibration condition of machines and equipment in accordance with ISO 10816.
The vibration sensors are integrated into the "2Touch" control system of decanter centrifuges, in which the other signals of speed, temperature and flow sensors are run together and evaluated. The holistic view of all measurement signals provides an extensive opportunity for machine diagnostics and condition-based maintenance. So that maintenance can be planned for the user, and sudden engine failure is excluded.
Peter Blomberg praises the cooperation: "IFM provides a good quality in their products. I enjoy working with the medium-sized companies, which goes straight to our wishes. An example of this are specific devices that have been adapted, for example, in the measurement and temperature range to our requirements towards ". All in all, "Good Vibrations" on the board.
The author is Andreas Biniasch, Technical Editor at IFM Electronic GmbH, Essen.