Process condition monitoring

Process condition monitoring system (sometimes also called technological monitoring system) These systems collect information from QCS sensors, vibration sensors, pressure sensors, triggers at rolls and fabrics, etc. to analyse the reasons for periodic quahty disturbances. AU collected signals are taken simultaneously with sample rates from 100 Hz to 4 kHz, depending on sensor type and application. The required measurement frequency is given by the revolution time of the machine elements which can cause quality variations, like felts, rolls, pumps, etc. 

The correlation results are calculated using time synchronous averaging. A process condition monitoring system can e. g. detect whether an applicator roll is responsible for periodic coat weight deviations, or whether a moisture variation is correlated with the revolution time of a press felt. 

Barring monitoring system This system identifies calender rolls which cause barring. Technically it works similarly to a process condition monitoring system. 

Use of Corrosion Probes The major use of corrosion monitoring probes is to measure the corrosion rate in the plant or the field. In addition to corrosion-rate measurements, corrosion probes can be used to detect process upsets that may change the corrosion resistance of the equipment of interest. This is usually equally as important a measurement as corrosion rate since a change in the process conditions can lead to dramatic changes in the corrosion rate. 

Borhaug, J.E., and Mitchell, J.S., Applications of Spectrum Analysis to Onstream Condition Monitoring and Malfunction Diagnosis of Process Machinery, Proceedings of the 1st Turbomachinery Symposium, Texas A M University, 1972, pp. 150-162. 

Boyce, M.P., and Cox, W.M., Condition Monitoring Management-Strategy , The Intelligent Software Systems in Inspection and Life Management of Power and Process Plants in Paris, France, August 1997. 

On the other hand, when workers are seriously under-loaded, they might not be very alert to changing process conditions. Many of the problems of plant automation are common to other situations of task underload. To increase the level of activity in monitoring tasks, additional tasks can be assigned, such as calculating the consumption of fuels, the life of a catalyst, the efficiency of the furnace and so on. Meister (1979) provides a summary of research on team organization. 

As an example of the importance of process parameters monitoring, consider a process pump that may be critical to plant operation. Vibration-based predictive maintenance will provide the mechanical condition of the pump and infrared imaging will provide the condition of the electric motor and bearings. Neither provides any indication of the operating efficiency of the pump. Therefore, the pump can be operating at less than 50 per cent efficiency and the predictive maintenance program would not detect the problem. 

A number of corrosion-monitoring techniques based on electrochemical principles are available. These give an indication of the instantaneous corrosion rate, which is of use when changing process conditions create a variety of corrosion effects at different times in a plant. Some... 

The Production Xpert A comprehensive production monitoring and control system that will maintain the optimized processing conditions determined with MPX s automated design of experiments. 

Processing intelligent What is needed is to cut inefficiency, such as the variables, and in turn cut the costs associated with them. One approach that can overcome these difficulties is called intelligent processing (IP) of materials. This technology utilizes new sensors, expert systems, and process models that control processing conditions as materials are produced and processed without the need for human control or monitoring. Sensors and expert systems are not new in themselves. 

Continuous and detailed knowledge of process conditions is necessary for the control and optimization of bioprocessing operations. Because of containment and contamination problems, this knowledge must often be obtained without sampling the process stream. At present, conditions such as temperatme, pressure, and acidity (pH) can be measured rapidly and accurately. It is more difficult to monitor the concentrations of the chemical species in the reaction medium, to say nothing of monitoring the cell density and intracellular concentrations of hundreds of compounds. 

These examples illustrate the importance of careful design, careful monitoring of conditions, and the need for periodic preventive maintenance programs when working with flammable gases and compressors. This is especially important today, because high-pressure process conditions are becoming more common in modern chemical plants. 

An environment should have appropriate controls for temperature, pressure, and relative humidity. For aseptic production, cleanroom conditions monitored for particles and bioburden contamination are necessary. Equipment must be validated and maintained with current calibration. Processes must be developed and validated to ensure the production of pure and consistent product. 

Because of the increasing complexity and necessity for safety of industrial processes, efficient monitoring and decision support systems are becoming more and more important. Indeed, even in normal operational conditions, several types of disturbances may occur with serious consequences in the performance of the process. Hence, there is a clear need for advanced control in order to keep the system performance as close as possible to optimal. 

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