Analysis of a ring‐shaped sensor for use in packed‐bed heat transfer studies

Abstract

A new type of ring‐shaped temperature sensor for packed‐bed heat transfer studies is presented. This ring‐shaped sensor is easy‐to‐build and allows one to filter the experimental angular temperature fluctuations. This device is more effective for beds of small tube‐to‐particle diameter ratio. The proposed device is able to eliminate the effect of the angular position on temperature measurements in packed beds. This sensor property is confirmed both experinientally and theoretically. For demonstration purpose, packed beds of six different materials were studied. Effective thermal radial parameters obtained using the ring‐shaped sensors have shown trends similar to published packed‐bed heat transfer data.

Analysis of the Heat Transfer in a Packed Bed with Cocurrent Gas−Liquid Upflow

“…The temperature above the bed of particles (T L ) was measured using a ring-shaped sensor 8 to damp the angular temperature fluctuation.…”

Analysis of the Heat Transfer in a Packed Bed with Cocurrent Gas−Liquid Upflow

“…The temperature above the bed of particles (T L ) was measured using a ring-shaped sensor 8 to damp the angular temperature fluctuation.…”

Angular temperature variations in a wall‐cooled packed‐bed reactor

“…All authors have observed angular variations increases in the neighborhood of the wall (see, e.g., Dixon and Paterson, 1978;Cresswell, 1986;Giudici and do Nascimento, 1994). Thus the amplitude apparently depends on the radial position in the tube.…”

“…Thus the amplitude apparently depends on the radial position in the tube. The angular spread also has been found to be larger for shorter bed lengths (see, e.g., Dixon, 1993;Giudici and do Nascimento, 1994). According to Dixon (1993), the reduced amplitude of the angular variations in temperature merely reflects the approach of the thermal field to a uniform temperature.…”

Mathematical simulation of radial heat transfer in packed beds by pseudohomogeneous modeling

“…1) and transmitted by a RS-232 interface to a computer. For temperature measurements, ring sensors were used, similar to those described by Giudici and Nascimento (1994), aiming to filter angular temperature oscillations. Temperatures were measured at r/R = 0, 0.16, 0.34, 0.48, 0.64, 0.78 and 0.94, at an interval of 15 min.…”

Analysis of the Heat Transfer in a Packed Bed with Cocurrent Gas−Liquid Upflow

“…The temperature above the bed of particles (T L ) was measured using a ring-shaped sensor 8 to damp the angular temperature fluctuation.…”

Angular temperature variations in a wall‐cooled packed‐bed reactor

“…All authors have observed angular variations increases in the neighborhood of the wall (see, e.g., Dixon and Paterson, 1978;Cresswell, 1986;Giudici and do Nascimento, 1994). Thus the amplitude apparently depends on the radial position in the tube.…”

“…Thus the amplitude apparently depends on the radial position in the tube. The angular spread also has been found to be larger for shorter bed lengths (see, e.g., Dixon, 1993;Giudici and do Nascimento, 1994). According to Dixon (1993), the reduced amplitude of the angular variations in temperature merely reflects the approach of the thermal field to a uniform temperature.…”

Mathematical simulation of radial heat transfer in packed beds by pseudohomogeneous modeling

“…1) and transmitted by a RS-232 interface to a computer. For temperature measurements, ring sensors were used, similar to those described by Giudici and Nascimento (1994), aiming to filter angular temperature oscillations. Temperatures were measured at r/R = 0, 0.16, 0.34, 0.48, 0.64, 0.78 and 0.94, at an interval of 15 min.…”

Analysis of the Heat Transfer in a Packed Bed with Cocurrent Gas−Liquid Upflow

“…The temperature above the bed of particles (T L ) was measured using a ring-shaped sensor 8 to damp the angular temperature fluctuation.…”

Angular temperature variations in a wall‐cooled packed‐bed reactor

“…All authors have observed angular variations increases in the neighborhood of the wall (see, e.g., Dixon and Paterson, 1978;Cresswell, 1986;Giudici and do Nascimento, 1994). Thus the amplitude apparently depends on the radial position in the tube.…”

“…Thus the amplitude apparently depends on the radial position in the tube. The angular spread also has been found to be larger for shorter bed lengths (see, e.g., Dixon, 1993;Giudici and do Nascimento, 1994). According to Dixon (1993), the reduced amplitude of the angular variations in temperature merely reflects the approach of the thermal field to a uniform temperature.…”

Mathematical simulation of radial heat transfer in packed beds by pseudohomogeneous modeling

“…1) and transmitted by a RS-232 interface to a computer. For temperature measurements, ring sensors were used, similar to those described by Giudici and Nascimento (1994), aiming to filter angular temperature oscillations. Temperatures were measured at r/R = 0, 0.16, 0.34, 0.48, 0.64, 0.78 and 0.94, at an interval of 15 min.…”