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Typescript (photocopy). / Digitized by Kansas Correctional Industries

A continuous process for the production of ceramic materials has been studied. This method reacted metal and oxidizer in a diffusionally controlled process, demonstrated by reacting a magnesium particle stream and hot water vapor. Many small rich hydrogen/air diffusion flames provide an atmosphere of hot water vapor, hydrogen, and nitrogen for oxidizing the magnesium, which reacts with the water vapor in the form of a diffusion flame. The burner that provides the hot atmosphere has been characterized thermally using thermocouple measurements and a model that gives the true temperature from the measured values. A model was developed that gives the flame profile for the parallel flow geometry of particle stream combustion used in this study as defined in the cartesian coordinate system. / Graduation date: 1995

No description available.

This thesis is concerned with the design of a decoupling compensator and a time-delay compensator for a nonisothermal continuous flow stirred tank reactor (CFSTR). An expression for the analysis of interaction of the two-variable CFSTR was theoretically derived by using the relative gain method (RGM). For the purpose of improving the stability of the decoupling control system, undercompensation for a decoupled CFSTR system was suggested and the robustness test of such undercompensation decoupler to the modelling error was studied. On the other hand, the proposed time-delay compensation method, unlike conventional Smith's scheme, can rely on the basic property of gain-invariant time-delay. The stability of this time-delay compensation method is not affected by the CFSTR control system time-variant time-delay, while its compensation structure has the same features as the Smith compensator. The design of a decoupler and that of a time-delay compensator are independent of each other. All compensation structures are physically realizable. The theoretical results are supported by simulation. Simulation results for a CFSTR demonstrate that the undercompensation decoupling control can tolerate a relatively wide modelling error and reduce the sensitivity of the CFSTR process to parameter variations and unwanted disturbances. Also, simulation results show that the proposed time-delay compensator can provide an improvement over the conventional Smith compensator. / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate

A two-phase experimental loop was designed and built to simulate the operating conditions of the SLOWPOKE reactor. Void growth was measured for both upflow and downflow for velocities between 0.07 to 0.46 m/s and at a pressure of 155 kPa. The buoyancy effect causes the Onset of Significant Void, OSV, to occur at higher subcooling for downflow than for upflow. This effect is maximum close to the bubble rise velocity (0.23 m/s) and decreases at higher velocities. The results indicate that bubble detachment is not the only critical parameter affecting OSV. The OSV correlations from the literature did not predict the experimental results well. Investigation of the heat transfer mechanisms indicates that fully developed sub cooled boiling occurs prior to OSV. / Applied Science, Faculty of / Mechanical Engineering, Department of / Graduate

A cold-flow model of a vibrated-bed microreactor has been designed and tested with capability for varying the level of gas dispersion (characterized by axial Peclet number) at a fixed weight hourly space velocity (WHSV). A tool has thus been provided whereby an important feature (viz., gas dispersion) of the reaction kinetic scene in large catalytic fluid beds can be simulated on a microscale, using approximately 5 grams of catalyst. Realization of a hot design of the microreactor (a task for another student) should permit the industrial chemist or chemical engineer, working at laboratory bench scale, quickly and inexpensively, to determine the sensitivity of a cataly1ic reaction to fluid-bed gas dispersion. The new microreactor exploits the coherent-expanded (C-E) vibrated-bed state, and is perhaps the first technical use of this state. The C-E state is achieved by subjecting a shallow layer of a fine powder to vertical sinusoidal vibration. The microreactor comprises a rectangular horizontal duct, 12.7 mm in height, 25.4 mm in width, variable in length, and with nonporous floor and walls. The microreactor is charged with a powder, such as fluid cataly1ic cracking (FCC) catalyst, at a compacted depth of I mm, and is vibrated at ~15 Hertz and amplitude of ~3 mm. Under influence of this vibration, the powder expands, displaying the C-E state. Between a phase angle of ~50° and an angle of ~150°, the powder assumes a depth of ~4 mm (i.e., expanded 4-fold from its compacted depth). Later, in each vibration cycle, the powder expands further. At ~300° phase angle, the powder reaches ~12.7 mm (i.e., collides with the roof of the microreactor duct). / Ph. D.

No description available.

No description available.

A subcritical heterogeneous nuclear reactor was designed and constructed for use in the nuclear engineering program at Virginia Polytechnic Institute. Natural uranium fuel and reactor grade graphite were used as building materials. Considering that no two samples of moderator have the same characteristics, the resulting parameters measured on this reactor are in good agreement with published data. The reactor performs the primary function as a versatile laboratory instrument that can measure as many reactor parameters as possible. / Master of Science