Application report
Market town of Thierstein: Modernisation of the pump controller in the waste water company using hydrostatic level probe
In the market town of Thierstein, the measuring and control equipment for monitoring the waste water shafts was no longer working reliably, and was replaced by a system from BD|SENSORS consisting of a hydrostatic level probe and a multifunctional process display.
Time and time again, municipalities and waste water companies are being confronted with the problem of how to deal with outdated measuring and control technology for waste water treatment, because problem-free operation of the system components is often no longer possible. The problem is not so much that the municipalities or waste water companies lack the financial resources, or that installation companies are not available. The main reason is that the measuring and control technology which has been installed is technically outdated and no longer available on the market in some cases.
Pump controller causing problems
This is what happened in the market town of Thierstein in Upper Franconia. In two waste water pumping shafts, problems were being encountered repeatedly with the pump controller and the transmission of system status information. The fill level monitoring was based on a bubble through system, whereas the signal processing had been implemented using various additional modules in order to achieve the required functionality. Following gradual deterioration of the system controller, the market town of Thierstein contacted specialist and manufacturer of electronic pressure and fill level measuring devices BD|SENSORS with a request for a system update.
During a joint site visit, the main characteristics (measuring range, distance from controller, explosion-proof design of measuring location) and the required functionality (pump controller, alarming, remote transmission) of the required system were defined.
New system consisting of hydrostatic fill level probe and process display
Based on this information, the BD|SENSORS technical sales department suggested the use of a type LMK 382 modern, hydrostatic fill level probe. The heart of the LMK 382 fill level probe is a capacitive-ceramic pressure sensor developed in-house by BD|SENSORS, which is extremely robust and durable because of its design, and also has high precision and long-term stability. Due to the structural design and the use of high-purity ceramic, damage to the sensor system is almost impossible, even if the waste water does not only contain suspended material and dirt, but also coarse material such as branches or stones. Another positive aspect is the fact that the LMK 382 can be adapted to the individual needs of the measuring location (measuring range, ATEX version, cable material etc.), which guarantees optimal measuring results and reliable system operation.
In order to maintain the existing functionality of the system in Thierstein the CIT 400 process display from BD|SENSORS has been used, which can be described as a proper all-rounder.
Essentially it is a galvanically isolated power supply amplifier with ATEX certification for Zone 0. Additional features include a 4-digit LED display, several potential-free switching outputs, an alarm relay and a scalable analogue output. The scope of functionality ranges from the standard settings (measured value display, switching points, analogue output etc.) to special functions such as linearisation, pump replacement and simulation mode/test mode. The latter is particularly important during commissioning, since it allows fill levels to be simulated and the system controller to be tested accordingly without the required fill levels being physically present.
Component replacement
Once the switching limits and the switching characteristics had been determined the required components were ordered, whereby BD|SENSORS also made a good impression with a short delivery time. After removing the old devices, the existing installation aids were able to be used (empty pipes, assembly pipes) in order to install the LMK 382 in the waste water shaft. Then the CIT 400 process display was installed, which was integrated into the existing control cabinet using a top-hat rail. Remote monitoring takes place on the basis of the scalable analogue output, and has been operating without problems ever since. After configuring the necessary parameters and performing several pump controller test runs, the replacement of the system was successfully completed.
This shows that the modernization of a municipal waste water control system, which took place using the LMK 382 hydrostatic level probe and the CIT 400 process display from BD|SENSORS in this case, can be implemented cost-effectively and quickly at any time and without having to apply for funding or approval procedures, since the entire conversion including parametrisation and testing took less than 2 hours.
If you have any questions about the system which has been described or have any problems with a similar application, please contact the technical sales department at BD|SENSORS GmbH:
Contact:
Mr. Roland Kottus
+49 (0)9235-9811-2009
