Heat transfer to a solids-air suspension

Author

Samuel Levinson, New Jersey Institute of Technology
Sanford Jerome Tick

Document Type

Thesis

Date of Award

6-30-1957

Degree Name

Master of Science in Chemical Engineering - (M.S.)

Department

Chemical Engineering

First Advisor

Jerome J. Salamone

Second Advisor

Joseph Joffe

Third Advisor

George C. Keeffe

Abstract

An apparatus for the investigation of heat transfer to air-solid suspensions was designed, constructed and operated. The apparatus consisted of a solids feeder (a fluidized bed), an air-solids mixing tube, a heat exchanger, and a solids separator.

The use of the fluidized bed as a solids feeder proved satisfactory from the standpoint of maintaining a constant feed rate and a constant solids to air ratio. Ease of variation of the solids to air ratio and air flow with the fluidized bed as a feeder was satisfactory, although difficulty was experienced in getting the desired solids to air ratio within a reasonable amount of time.

Zirconium silicate suspended in flowing air by means of the fluidized bed type feeder was heated by condensing steam in a double pipe heat exchanger. The presence of a solid in a gas stream should increase the heat transfer coefficient mainly by the effect of the solid particles breaking through and disturbing the laminar boundary layer at the wall. Unfortunately, the solid available for this study (zirconium silicate 100% minus 5 micron) coated the walls of the heat exchanger thereby masking any advantage gained. This preliminary investigation did reveal an increase in heat transfer coefficient with increase solids/air ratio. The approximate relationship at a constant mass air flow was h=α(air/solids)² . Further investigation with solids that do not coat the exchanger wall is needed. Due to the difficulty experienced and time consumed in designing and constructing an apparatus with the proper characteristics, enough time was not available to investigate a solid of larger particle diameter.

Recommended Citation

Levinson, Samuel and Tick, Sanford Jerome, "Heat transfer to a solids-air suspension" (1957). Theses. 2533.
https://digitalcommons.njit.edu/theses/2533