New Calibration Technique for X-ray Absorption Studies in Single and Multiphase Flows in Packed Bed

Abstract

An X-ray technique has been developed to determine the concentration and liquid holdup in a packed bed. To quantify these parameters in single and multiphase flow systems, at local level, a calibration method/graph has been developed. This graph has also been used to obtain the local concentration value of a liquid in presence/absence of another miscible liquid in a porous media. The same graph has been used to quantify the local liquid holdups (static and dynamic) in a packed bed. The same technique can be used for other radiological methods such as gamma rays and neutron radiography. Results obtained from this technique are in agreement with the published data.

Quantification of Liquid Holdup in the Dropping Zone of a Blast Furnace—A Cold Model Study

“…The situation is worse when multiple species are present in the absorbing material. Due to all of these uncertainties, recently, a new method has been developed by a few researchers, [14,19] which not only takes care of the polychromatic nature of the beam but also the mass absorption coefficient. Also, the method has been simplified further by removing most of the image processing operations.…”

“…The same method is used in this article. Detail of the method is given elsewhere, [14,19,20] but the basic steps are outlined subsequently. Consider a packed bed of plastic beads through which liquid is flowing.…”

“…More details on the X-ray machine and associated accessories including the computer are given elsewhere. [19,20] The movie thus recorded is digitized into snapshots/ frames using StreamPix and Image Pro plus software. These snapshots, which are the still images of the test sample, can be analyzed to explore the intensity variations occurring in the test sample.…”

“…This technique is described in brief in Section II. For full detail of the method, its validity, and the errors associated with it, readers are encouraged to go through References 14,19, and 20.…”

“…Subsequently, a few authors have reported different techniques for visualization and quantification of liquid holdups using X-ray [14,15] and neutron [16] radiography and other methods. [17,18] It is demonstrated that X-ray radiography [14,[19][20][21] can be used successfully to estimate the various local liquid holdups and to explain the dispersion and liquid hysteresis phenomena. We claim this technique gives better estimates of liquid holdup than do conventional methods.…”