What is entrainment in fluidized bed?
Entrainment is the carryover of particles from the fluidized bed. In the simplest sense, when the gas velocity exceeds the terminal velocity of a particle, one would expect the particle to be removed from the bed. This is indeed the case.
At what velocity entrainment of particles in the fluidized bed takes place?
3. At what velocity entrainment of particles in the fluidized bed takes place? Explanation: At terminal velocity entrainment starts, when velocity is more than terminal velocity complete entrainment takes place.
What is bubbling fluidised bed?
Boilers. A bubbling fluidized bed (BFB) boiler is a boiler that can also handle fuels that are difficult to pulverize or less combustible. The fuel is introduced into a mixture of sand flowing at high temperatures, allowing the fuel to be efficiently combusted.
What is the meaning of entrainment?
1 : to draw along with or after oneself. 2 : to draw in and transport (something, such as solid particles or gas) by the flow of a fluid. 3 : to incorporate (air bubbles) into concrete. 4 : to determine or modify the phase or period of circadian rhythms entrained by a light cycle.
What is the meaning of entrained velocity?
The entrainment velocity is expressed as the ratio of a relevant length scale to a time scale for all flows, a generalization of the original entrainment hypothesis of Morton, Taylor, & Turner.
What is the difference between particulate and bubble fluidization?
Particulate fluidization shows a structure of idealized fluidization with complete homogeneity. Aggregative fluidization is characterized by a clear two-phase structure, including the bubble phase and the emulsion phase. The structure of bed would change at the transition from particulate to aggregative fluidization.
What do you mean by entrainment?
What is entrainment effect?
Entrainment is a phenomenon of the atmosphere which occurs when a turbulent flow captures a non-turbulent flow. It is typically used to refer to the capture of a wind flow of high moisture content, or in the case of tropical cyclones, the capture of drier air.
What is entrainment in chemistry?
To draw in and transport (as solid particles, liquid droplets, or gas) by the flow of a fluid.
Why is fluidization important?
These chemical reactions are highly exothermic and fluidization ensures a uniform temperature, minimizing unwanted side reactions, and efficient heat transfer to cooling tubes, ensuring high productivity.
What are the different types of fluidization?
Based on different Geldart particle groups and gas velocities, several different fluidization regimes can be observed: fixed bed, homogeneous fluidization, bubbling fluidization, slugging fluidization, turbulent fluidization, and entrainment process.