Continuous stirred tank reactors (CSTRs) are widely used in the chemical industry. Their agitator systems are susceptible to mechanical faults, which can lead to unplanned downtime during operation. The Rotating Machinery Manager from WIKA is an IIoT solution for condition monitoring and predictive maintenance of rotating equipment. A chemical company used it to prevent major damage to one of its continuous stirred tank reactors.
A continuous stirred tank reactor provides a stable and homogeneous reaction environment. Feedstocks are continuously introduced and mixed by constant agitation while the reaction product is withdrawn at the same time. At the heart of the process is a mechanical agitation system, typically driven by an electric motor. This motor drives a central shaft connected to impellers that thoroughly mix the reactants and maintain consistent process conditions throughout the reactor.
Typical applications: Fermentation and chemical synthesis
Reliable operation of the motor and agitator is essential, especially in sensitive applications such as fermentation and chemical synthesis. In fermentation, effective mixing is required to supply microorganisms evenly with nutrients and oxygen – a prerequisite for their growth and optimal product yield. In chemical synthesis, uniform agitation is important so that temperature and component concentrations remain consistent throughout the reactor. Only under these conditions can the reaction rate be controlled and product quality assured.
Challenges and risks during operation
The agitator system therefore plays an important role in the process. However, its mechanical components are susceptible to faults, posing a potential source of failure. High-viscosity media or mixtures with a high solids content can, for example, overload the motor and potentially lead to equipment failure. Shaft misalignment can result in vibration, noise and accelerated bearing wear. In continuous stirred tank reactors – particularly in pressurised systems – there is also a safety and contamination risk due to the possibility of seal leakage. If such faults lead to poor mixing and, consequently, incomplete reactions, this results in costly downtime.
The solution: Smart condition monitoring with IIoT
A chemical company operating a series of continuous stirred tank reactors for the production of specialty chemical intermediates sought a solution to these challenges – and implemented the Rotating Machinery Manager from WIKA. This modern IIoT solution was developed for condition monitoring and predictive maintenance of rotating equipment. Its core component is a multisensor probe that measures vibration, ultrasound and temperature. It is certified for hazardous areas, operates wirelessly via LoRaWAN® and offers a long battery life. The instrument collects data from the
measuring points in the plant and transmits them to a central dashboard. On this dashboard, the operator can continuously monitor the operating state of the reactors remotely. Thanks to the integrated AI engine, potential causes of failures can also be detected and addressed at an early stage.
The Rotating Machinery Manager from WIKA detects signs of mechanical faults such as bearing wear, insufficient lubrication, overheating, cavitation and misalignment. It gains these insights using edge computing to process complex sensor data as well as AI-based analytics that detect anomalies and indicate likely root causes. This information allows maintenance teams to act early, minimising unplanned downtime and extending the service life of the equipment.
Success story: Major damage avoided
The new monitoring solution quickly proved its effectiveness for the chemical company. During ongoing operation, the bottom bushing inside a continuous stirred tank reactor showed signs of advanced wear. The Rotating Machinery Manager detected the anomaly and issued an early warning. Thanks to this warning, the maintenance team shut down the reactor. This prevented the situation from escalating to the point where the upper mechanical seal – a more critical and costly component – would have been affected.
When the warning appeared, the maintenance team responded immediately, stopped reactor operations over the weekend and inspected the plant. They found that the bottom bushing was severely damaged. The monitoring solution had correctly raised the alarm, thereby preventing an even more serious failure. If the Rotating Machinery Manager had been deployed earlier, the operator would have become aware of the fault even sooner. Then damage to the bushing could have even been avoided altogether. This highlights the enormous savings potential of effective predictive maintenance using IIoT.
Benefits for operators of CSTRs
A multisensor probe captures precise measurement data and a digital analytics tool presents them clearly.
The Rotating Machinery Manager offers operators of continuous stirred tank reactors several benefits. It does not require major interventions in the plant layout and is compatible with virtually any machine type and age. The wireless technology allows installation even in hazardous areas. The solution enables operators to remotely monitor the operating state of the reactors. Parameters can be adjusted without having to access the machinery in person. The benefits for operators are clear: reduced downtime, improved safety and compliance, optimised plant performance, higher energy efficiency and lower maintenance costs.
The implementation of the Rotating Machinery Manager from WIKA includes the following project steps:
- Joint inspection of the plant, assessment of the current situation and identification of the best possible sensor positions
- Installation of a multisensor probe with the required ATEX approvals for agitator motor monitoring
- Measurement of signal strength and setup of the network
- Installation of a LoRaWAN® gateway on the plant premises – the gateway collects sensor data within a radius of several kilometres
- Setup of the WIKA dashboard and alarm system – 24/7 monitoring of the operating state of the agitator motor through collection and intelligent analysis of ultrasound, vibration and temperature data
- Joint root cause analysis
Conclusion: Higher safety and availability thanks to IIoT
Predictive maintenance of stirrers in continuous stirred tank reactors is a crucial lever to avoid unplanned downtime, safety risks and high consequential costs. The Rotating Machinery Manager from WIKA demonstrates how mechanical anomalies can be detected early using IIoT, intelligent sensing technology and AI-supported analysis. The case study from the chemical industry illustrates that smart condition monitoring can not only prevent damage but also sustainably increase the availability and efficiency of the plant.
Note
Further details on the Rotating Machinery Manager can be found in our brochure. Also visit the WIKA website for more information on predictive maintenance of rotating machinery. Do you have a specific question? Your contact at WIKA will be pleased to assist you.
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