- News
- Management
- Board of Directors
- Investors
- White Papers
- Careers
- Terms and Conditions
ISO 9001 Certification
Zolographics™ Combustion CAT Scanning
The ZoloBOSS™ generates tomography based on a grid of path average measurements in order to depict the spatial distribution of temperature or a particular chemical species. In general, this rough tomography is generated in much the same way as the more complex computer aided tomography (CAT) scans used in medical imagery.
Zolographics can be generated from any grid of laser measurement paths anywhere in the boiler. Paths do not have to be equally spaced and are not required to be rectilinear. Installing more paths increases the resolution and usefulness of a given tomographic map, but as little as four paths can provide valuable information used for tuning and balancing boiler performance. Furthermore, Zolographics at any elevation are generated for each available constituent and temperature simultaneously.
Path Intersection Points
First, path intersection points are calculated based on the ZoloBOSS path average measurements. A low resolution image is generated from intersection points using methodologies similar to those used in CAT scans.
The simplest case is for equally spaced, rectilinear path averages. As an example, the path average readings for a 5 x 4 path grid are shown in the table below.
| N-S Paths | E-W Paths |
|---|---|
| P1=4.456 | P6=2.785 |
| P2=4.735 | P7=3.547 |
| P3=4.238 | P8=4.788 |
| P4=3.322 | P9=4.457 |
| P5=2.721 |
The first step in going from one-dimensional path averages to a two-dimensional image is to apply an algorithm which generates values at the path intersection points.
Smoothed Image
Starting with the values at path intersection points, the next step in the ZoloBOSS tomography algorithm is to assign values to the boiler walls using the value at the nearest grid point. Appending the boundary values fills out the image so the appearance of the smoothed image is more consistent with the actual size of the measurement plane. Using this approach, the smoothed image values are nearly constant perpendicular to the boundary between the boundary and the nearest parallel path. The final image is generated using natural bi-cubic spline interpolation to fill in values between grid points. This leads to the following smoothed image.
The properties of the natural cubic spline are such that the values at the path intersection points are equal in both the low and high resolution images.
Images like the one above can indicate a boiler that is out of balance and enables operators to see the effects of, for example, burner tilts or mill adjustments, in real time. Measurements like these can take place directly in the combustion zone. They can be correlated with existing instruments or additional ZoloBOSS grids in the back-pass and facilitate tuning and performance never before possible.