Reliable data retrieval for a safer and more efficient sewage treatment plant
Sewage treatment is a multi-stage process designed to treat sewage and protect natural water bodies. In order to keep the treatment plant working smoothly, it usually relies on many inspectors at the field site, which is usually a harsh and dangerous environment. The question is “How can we ensure the safety of the inspectors? ” “Is there any solution to narrow down the time they spend within the danger area? ” This is one of the reasons why it is important for treatment plants to transit into smart and intuitive buildings - to improve workplace health and safety. Furthermore, it can also reduce staff and utility costs.
Smart treatment transition requires control and management of all those equipment and facilities. It is for sure a complex task thatrequires thousands of measurement devices to provide constant data to various locations. Because of the large quantity of devicesand the standardization that IEEE compliant devices offer, Ethernet is used as the communication standard around the plant site. Areliable Ethernet network within the wastewater treatment plant is required in order to receive and provide constant and accurate data.
Our mission is to build up a wireless network that covers the entire water treatment plant. Inspectors can access all the data by using a tablet or smartphone and they don’t need to reach every corner. By using WI- FI technology, it can narrow down the distance and time of inspection. However, wastewater treatment plants can be extremely large in size and can geographically cover hundreds of acres of land.
In this case, it covers multiple buildings, some open areas, underground tunnels and some even with cylinder concretes, which makes the Wi-Fi coverage more difficult.
In the beginning, the end customer wishes to use a Wi-Fi device only, which means not using any wire inside the treatment plant. In order to achieve this goal, it requires star- topology with multiple Wi-Fi repeater mode access points. But it brings out another risk, if any of the device has lost connection, there is no backup device. Star topologies are often used in home networks and is usually kept small because network performance can suffer when too many devices compete for access to the central node. Some buildings cover long distances of over 500m, thus the star topology may not be a suitable solution for this kind of large geographical area.
Another challenge in the treatment plant is that there is corrosive gas in many buildings. The end user claimed that based on their experience, many devices broke down within 3 to 4 months after all the equipment were deployed. We need to provide a solution which can survive in this kind of extreme environment.
• Harsh environment with corrosive gas, temperature and humidity challenges
• Large geographical area that covers an open area, several buildings with concrete that may block Wi-Fi signal, and an underground tunnel
• Zero down time with 24/7 usage
• Advanced monitoring and management control
In this kind of large area, it is better to use a physical line to connect each building or area. Then use Wi- Fi devices to transmit within the vicinity of each building. In order to reach a 500m distance we selected switches with a fiber port. It allows our devices to reach over 2 km. Another benefit is that with the Korenix MSR ring network, it can provide a backup system. If any single port or device is disconnected, we still have a backup. Korenix MSR connects all devices in your network in a daisy chain. Data travels from one device to the next until it reaches its destination and finally back to the operations center. This configuration requires less cabling and trenching than alternative star topologies and thus is simpler and more cost-effective to implement.
Secondly, for the Wi-Fi solutions, since there are many open areas in the treatment plant, it requires the Wi-Fi access point to use omni antenna to receive and transmit the data. However, there are still some underground tunnels in some buildings so it also requires a Wi-Fi repeater mode to do the bridge out.
There are a total of 12 buildings with completely different environments. The Korenix JetWave 4211 can help achieve full Wi- Fi coverage in such complex area and can provide reliable Wi-Fi connection for each area. In this case, the inspector’s walking distance and time in the danger area could be reduced.
In other words, we can provide a more safe environment by implementing the smart treatment plant.
Why Beijer Electronics/Korenix?
• IP68 outdoor design - There are lots of corrosive gas around the plant. In the past many Wi-Fi AP only survive for several months. The IP 68 outdoor design can resist this kind of harsh environment.
• AP Roaming redundant function - When an end user uses another device like a smart phone or tablet, usually it does not support a roaming function. Under this condition, if user
connects to the Original AP but the Wi-Fi signal is getting weak, the smart phone or tablet will still connect to it.
By implementing the AP roaming function, AP will detect each client’s signal. If the signal is weak, AP will disconnect the Client and force it to connect to a better AP.
• PoE function design - There are many limitations about the power source at the treatment plant. Some extreme locations do not allow extra power cables or supplies to be added in, which makes the network design more critical. Under this
situation, the PoE function for the switch and Wi-Fi AP can provide flexibility at the field site.