Record Details
Field | Value |
---|---|
Title | An investigation of the effects of immersed heat exchanger tube spacing and arrangement on the quality of fluidization in a cold phase two-dimensional fluidized bed |
Names |
Lockwood, Dwight Norris
(creator) Junge, David C. (advisor) |
Date Issued | 1976-04-15 (iso8601) |
Note | Graduation date: 1976 |
Abstract | The feasibility of fluidized bed combustion of coal for commercial and industrial steam power generation has been established and reported in the literature. Satisfactory removal of sulfur oxides from the combustion product gases has also been reported. In this experiment various heat exchanger tube patterns, of commercial size tubes, were examined in a two-dimensional, cold phase fluidized bed of limestone and dolomite. Several variables such as tube pitch (triangular and rectangular), tube spacing (horizontal and vertical), array location with respect to the distributor plate, and superficial gas velocity were considered and their effect on the quality of fluidization reported. Dolomite with a mean surface/volume size of 569 microns (28 Tyler mesh) and limestone with a mean surface/volume size of 1379 microns (12 Tyler mesh) were used as bed material. The results indicate that the horizontal as well as vertical spacing of tubes has a significant effect upon the start up phase of fluidization and bed stability. Also, horizontal spacing which is too close inhibits solids circulation. Triangular pitch arrangements yielded good solids circulation and did not experience gas by-passing to the extent seen with rectangular arrangements. Overall bed stability was improved with the tube arrays closer to the distributor plate. Rapid bubble growth and associated instabilities were observedwhen.a relatively thick layer of solids were above the tube arrays, indicating that the expanded bed surface should probably not extend above the tubes. Further research in the area of fluidized bed quality is recommended. |
Genre | Thesis/Dissertation |
Topic | Heat exchangers |
Identifier | http://hdl.handle.net/1957/46201 |