How does ProSpect work?
The ProSpect family of products is based on harnessing the science of spectroscopy and applying it to industrial processes. ProSpect utilizes the same technology as laboratory grade spectrometers for in-line continuous control of process systems.
Continuous control allows for the maximization of product yield since the product is tested continuously, and any process changes that are necessary are made instantaneously.
In order to understand how ProSpect operates and ultimately delivers process control, it is necessary to have a fundamental knowledge of spectroscopy theory and how spectrometers perform their measurements.
Spectroscopy is the study of the interaction between matter and radiated energy.
Electromagnetic radiation is defined as a self propagating wave that is composed of both a magnetic and an electronic component which travels through space and can also travel through matter. The properties of the wave are defined by its wavelength, frequency and amplitude.
The electromagnetic spectrum consists of all possible types of electromagnetic radiation. This varies from radio waves on one end of the spectrum to visible light and on to x-ray and gamma rays at the other end. A spectrometer measures and calculates the amount of radiation (in the form of light) that is passed through or reflected by the molecules of matter in a sample of the material being produced.
Near Infrared (NIR) Spectroscopy
Near infrared or NIR spectroscopy is the measurement of the wavelength and intensity of the absorption or reflectance of near infrared light by a sample. ProSpect’s spectrometer is designed to measure the near infrared (NIR) region of the electromagnetic spectrum (from about 700 nanometers to 2500 nanometers).
Near infrared light ranges from 700 to 2500 nanometers.
The instrumentation of NIR spectroscopy is comprised of a light source, usually a tungsten lamp and a detector. This arrangement is uniquely suitable for true in-line monitoring and process control of a variety of components in a flowing stream. The transmitted light is compared to the light available and a prediction is made based on a sophisticated algorithm.
Total Process Control
ProSpect’s internal computer instructs the spectrometer to compute a scan every 70 seconds and this information is plotted on the operator control screen. As the product is scanned, the results are displayed and plotted for each constituent. Each scan is plotted against the distance from the constituent target, or calibration. This output information, the predicted values along with target set points, can be sent to the PLC and used to control the process automatically.
Predicted Value vs. Actual Target Set Point
This trend chart from an actual installation shows how accurately ProSpect controls the process. The blue line is the actual predicted value of Protein divided by Total Solids. The red line is the actual set point – in this case just above 80% PDB (Protein Dry Basis) indicating the protein concentration is 80% of the total solids.
Utilitizing ProSpect to facilitate total process control results in a lower standard deviation of constituent concentrations, meaning that a more consistent product is produced. This also lowers laboratory and operating requirements by reducing the need for samples to be analyzed in the lab and then having to manually adjust the system.
ProSpect reduces waste by helping to reduce out of spec product as well as product giveaway. It helps to ensure consistency while manufacturing a product since it samples continuously and makes the necessary adjustments much more frequently, which keeps the product closer to target.
Continuous sampling also helps to improve consistency by using controlled uniform adjustments instead of hand adjusting the system. Consistency is assured between product changes, since each product runs the same way every time it is produced.