International Journal of Engineering and Technical Research (IJETR) ISSN: 2321-0869, Volume-2, Issue-11, November 2014 299 www.erpublication.org Abstract — This paper includes the experimental work involved in fluidization- the most efficient method for contacting fluid and particles. Mustard seed and sago are used one after the other and their transformed behavior from fine solids into a fluid like state are observed through contact with air or methyl alcohol. Calculation of minimum fluidization velocity is accompanied by Graphs for both test materials between (a) bed pressure drop and velocity and (b) Reynolds number and Bed expansion ratio. Index Terms—Bed expansion ratio, Bed pressure drop, fluidization, minimum fluidization velocity, Reynolds number, sphericity, voidage I. INTRODUCTION “The arrival time of a space probe traveling to Saturn can be predicted more accurately than the behavior of a fluidized bed chemical reactor.” Even though the above quotation (Geldart, 1986) is almost 20 years old it remains true in the new millennium of fluidization engineering. The difficulties in prediction stem in part from the complexity and ambiguity in defining the fundamental parameters such as size, shape and density of the particles. These parameters play an important role in the calculation and prediction of dynamic behavior in fluidized beds. Most physical properties of the particles are estimated indirectly, such as estimating particle shape by the bed voidage. All factors are explicitly and implicitly significant in the estimation of the behavior of fluidization operations. Although new technology is helping us to understand and give more precise prediction in fluidization, more research is still needed. II. REVIEW OF FLUIDIZATION BASICS Fluidization is a process in which solids are caused to behave like a fluid by blowing gas or liquid upwards through the solid-filled reactor. Fluidization is widely used in commercial operations; the applications can be roughly divided into two categories, i.e., • Physical operations, such as transportation, heating, absorption, mixing of fine powder, etc. and Manuscript received November 22, 2014. Abhishek Kumar, B.Tech Graduate (Dept. of Chemical Engineering) B.I.T Sindri (Pin-828123) Dhanbad (Vinoba Bhave University) India, +91-9835336577 Amit Kumar Gupta, Assistant Professor (Dept. of Chemical Engineering) B.I.T Sindri (Pin-828123) Dhanbad (Vinoba Bhave University) India, +91- 9835785852 Amar Kumar, Assistant Professor (Dept. of Chemical Engineering) B.I.T Sindri (Pin-828123) Dhanbad (Vinoba Bhave University) India, +91-9334281501 • Chemical operations, such as reactions of gases on solid catalysts and reactions of solids with gases etc. The fluidized bed is one of the best known contacting methods used in the processing industry, for instance in oil refinery plants. III. FLUIDIZATION REGIMES When the solid particles are fluidized, the fluidized bed behaves differently as velocity, gas and solid properties are varied. It has become evident that there are number of regimes of fluidization, as shown in Fig 1. When the flow of a gas passed through a bed of particles is increased continually, a few vibrate, but still within the same height as the bed at rest. This is called a fixed bed. With increasing gas velocity, a point is reached where the drag force imparted by the upward moving gas equals the weight of the particles, and the voidage of the bed increases slightly. This is the onset of fluidization and is called minimum fluidization with a corresponding minimum fluidization velocity, U mf . Fig 1 Schematic representation of fluidized beds in different regimes (based on Kunii and Levenspiel, 1991) Now, with increase in the gas flow further, formation of fluidization bubbles sets in. At this point, a bubbling fluidized bed occurs. As the velocity is increased further still, the bubbles in a bubbling fluidized bed will coalesce and grow as they rise. If the ratio of the height to the diameter of the bed is high enough, the size of bubbles may become almost the same as diameter of the bed. This is called slugging. If the particles are fluidized at a high enough gas flow rate, the velocity exceeds the terminal velocity of the particles. Momentum Transfer in Fluidized Bed Abhishek Kumar, Amit Kumar Gupta, Amar Kumar