An accurate prediction of the minimum fluidization velocity is a crucial hydrodynamic aspect of the design of fluidized bed reactors. Common approaches for the prediction of the minimum fluidization velocities of binary-solid fluidized beds are first discussed here. The data of our own careful experimental investigation involving a binary-solid pair fluidized with water is presented. The effect...

in order to study the fluidization behavior of grains, a laboratory fluidized bed dryer (fbd) was designed and developed. forward blade centrifugal fan with 1.5 kw electric motor, was selected to be used based on the highest pressure loss calculated at minimum fluidization condition and airflow rate at terminal velocity of the selected grains (paddy, soybean, millet and barley). the dryer was c...

Fluidized beds are used in a variety of process industries because they provide uniform temperature distributions, low pressure drops, and high heat/mass rates. Minimum fluidization velocity is an important factor in understanding the hydrodynamic behavior of fluidized beds, and this characteristic may be modified through high frequency (sound) vibrations. The effects caused by sound wave frequ...

Some experimental observations on the fluidization characteristics of nanoparticles in the form of agglomerates with magnetic assistance are presented. The nanoagglomerates consist of Degussa Aerosil R974 fumed silica, with a primary particle size of 12 nm. An oscillating AC magnetic field is used to excite large (mm size) permanent magnetic particles mixed in with the nanoparticle agglomerates...

An experimental study is conducted to determine the effect of different types of nanoparticles on the gas fluidization characteristics of nanoparticle agglomerates. Taking advantage of the extremely high porosity of the bed, optical techniques are used to visualize the flow behavior, as well as to measure the sizes of the fluidized nanoparticle agglomerates at the bed surface. Upon fluidizing 1...

The fluidization characteristics of binary mixtures containing tobacco stem (TS) and cation exchange resin (a substitute for coal) were studied in a rectangular bed with the cross-section area of 0.3 × 0.025 m(2). The presence of herbaceous biomass particles and their unique properties such as low density and high aspect ratio resulted in different fluidization behaviors. Three fluidization vel...

The present work is focused on the study of fluidization behaviour of biomass and sand mixtures in a laboratory scale test set up. The biomass materials used during the experimentation were rice husk, bagasse and sawdust. Two different particle sizes of silica sands were used in forming the mixture. The percentages of biomass in the mixtures were 2%, 5%, 10% and 15% by weight. The minimum fluid...

Changes in fluidization behaviour of green peas particulates with change in moisture content during drying were investigated using a fluidized bed dryer. All drying experiments were conducted at 50 + 2 0C and 13 + 2 % RH using a heat pump dehumidifier system. Fluidization experiments were undertaken for the bedheights of 100, 80, 60 and 40 mm and at 10 moisture content levels. Fluidization beha...

The fluidization behavior of silica gel was tested in a fluidized bed under different sound pressure levels and sound frequencies. It has been found that the particle mixtures can be fluidized smoothly with sound assistance at low sound frequency owing to the sound energy disrupting large size of agglomerates. The minimum fluidization velocity was found to decrease with increasing sound frequen...

black tea sample was dried by a vibro-fluidized bed dryer to find its aerodynamic behavior and thermal performance during drying. the drying experiments were conducted at three different inlet air temperatures of 100, 115 and 130°c and fluidization condition at five vibration intensity levels of 0 (no vibration), 0.063, 0.189, 0.395 and 1.184. the results showed that bed channeling and defluidi...