In our last article, we discussed about why it is important to keep an eye on condition of rotating machines in a Cement Industry & the main objectives of monitoring vibration. In this article we will see how can cement industry benefit from Vibration Monitoring.
Why do we need Condition Monitoring for fans, motors, mills?
There are lots of rotating equipment in a cement industry. The quarry operations consist of drilling, blasting, excavating, handling, loading, hauling, crushing, screening, stockpiling, and storing. There are lots of motors being used in this process. Raw milling involves mixing the extracted raw materials to obtain the correct chemical configuration, and grinding them to achieve the proper particle-size to ensure optimal fuel efficiency in the cement kiln and strength in the final concrete product. Lots of rotating equipment are involved in this process.
In Pyroprocessing, it is important to have longer life of the kiln, which also has rotating portions. Fans are used in clinker cooling applications. Clinker storage, finish milling, packing & loading processes involve lots of rotating portions in conveyors, roll crushers & elevators. All these rotary items are extremely important for the processes, handle hard objects, have to survive in dirty environment & still live long life with less downtime. There is no substitute for Vibration Monitoring in such applications.
Let’s see some of the important aspects of Vibration Monitoring in relation with cement industry :
- It is now imperative to monitor the plant to increase the plant uptime to 95%.
- In cement plants, most of the critical machines have rotating components.
- In today’s competitive scenario it is imperative to monitor these machines to increase the efficiency and therefore reliability of the plant.
- The vibration monitoring solution is one of the most cost effective as a maintenance tool and helps in ensuring the total availability of plant.
- Condition characteristics of the machine such as bearing damage, imbalance, alignment or cavitation enable a differentiated evaluation of mechanical stress. This would indicate when to have the shutdown and when the process can be ongoing without any manual interruption. This ensures that the equipment is protected from expensive consequential costs.
- For taking the machines for maintenance, we need to know the state of health of the machine without dismantling it. This is possible only by online monitoring. Implementing predictive maintenance leads to a substantial increase in productivity by to up to 35%.
Philosophy of Condition Monitoring and Solutions for Cement Plants
Typical schematic – Option 1: Accelerometer with Field mount transmitter
- Typical applications where condition monitoring is applicable are kiln drives, separators, crushers, screens, gear boxes, conveyor belts, fans, raw mills, ball mills, elevators and blowers.
- It is essential to use portable instruments, online systems and accessories of rotating machinery and vibration monitoring equipment for detecting misalignment, gear problems, balancing problems etc.
The above figure shows a typical example of Fan-Motor, Crusher motor application. The motor has 2 bearings and the fan has 2 bearings ( DE & NDE ). Every bearing needs to have 02 sensors (accelerometer / velocity). Ideally accelerometer sensors are mounted on DE & NDE bearings of machine casing in X-Y directions with the help of a mounting pad. 10 meter extension cable with SS conduit is used to connect sensor and the field mounted transmitter. Accelerometer gives millivolt output which is connected to the monitor. Further 4-20mA output is available through monitor which can directly be taken to PLC/DCS system. The field mounted transmitter is a dual channel monitor which gives 4-20mA output, relay output, raw buffer output.
In our next article, we will discuss further about how can one use Vibration Monitoring for improving operational efficiency & uptime of machines