What are X-rays?

X-rays are photons similar to light but with higher energy. They are produced by accelerating electrons which then strike a target. Removing electrical power stops any X-rays being produced. X-rays are attenuated (or absorbed) in different ways depending on the energy and the type of material it is passing through. Higher density materials, with more atoms in the material, will absorb more than low density materials.

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Quantitative Dual-energy X-ray Absorptiometry (qDXA)

qDXA uses two X-ray beams, each with a different energy, and two high resolution detectors, to measure the amount of photons absorbed in the organic material. The software can then measure the amount (quantity) of the selected atoms – usually oxygen and carbon. As the material moves under the scanner clever algorithms calculate various physical parameters such as weight, moisture, energy value etc.

In addition, the technology also provides for a visual picture (like a normal X-ray image) which allows us to identify material with higher densities –  usually debris such as metal and plastic.

The scanners are calibrated and verified against accepted measurement techniques such as the gravimetric (oven) method.

From theory to practice

Each measurement application is determined on an atomic level. The amount of attenuation of a beam of X-rays depends on the type of atom, how closely packed the atoms are, and the thickness of the material. The key elements in a material are identified and suitable X-ray energies and intensities selected. The amount of attenuation of the X-rays due to these different elements is measured and algorithms used to calculate the weight or moisture content. Corrections are made for the material holder and the readings calibrated against trusted reference methods.

The data is calculated for each pixel on the detector to form a 2-dimensional map. Here image analysis can be used to measure the surface area of foreign objects and determine if an alarm should be triggered.

Organic material properties

All organic material contains Oxygen and Carbon atoms with sufficient density to record the attenuation of X-rays. The material is analysed in the laboratory to determine the amount of Oxygen atoms bound within the material. The amount of attenuation of the high energy and the low energy beams is then run through several algorithms to tell us about the material composition. Attenuation due to other elements can be measured by changing the energy according to the application requirements.

Inorganic material has much higher attenuation withe very little signal reaching the detector. This shows up clearly when the pixels are arranged to make a two dimensional image.

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Real-world applications

Mantex’s goal is to enable the raw materials harvested on our planet to be used in the most efficient way. Analysing large volumes of these materials to provide forehand knowledge makes it possible to optimise the production process. This could be to use less energy, have higher yields, less waste, use less chemicals or ensure payments are based on the material value. Its good for business and good for the environment.

 

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Well suited for industrial processes

The products Mantex manufacture have been designed to take this advanced technology to industrial environments. Features such as airtight capsules, splashproof, pressurised air nozzles, swap-out components, automatic diagnostics and fault reporting, remote access may be included according to the application requirements.

Pulp and paper industry

The Flow Scanner can deliver information such as moisture content, mass flow, and bulk density. The geometry of the X-ray beams means all the material being used is measured. The information can be used to control the pulp process in a more effective way.

Bio energy applications

Whether installed at the material delivery station or within the boiler building the Flow Scanner can be adapted to suit the different environments. The key elements measured use algorithms to determine the energy value, mass flow, and other elements such as ash content.

Other industries

There are many other process industries that would be significantly improved by dynamic control based on the raw material variations. The technique can be applied to many different materials and measure many different properties.