Pressure Velocity Characteristics: A Literature Review on Fluidization

This literature review examines the relationship between pressure velocity characteristics and minimum fluidization velocity, drawing on various studies and perspectives. It highlights the importance of parameters like drag coefficient, viscosity, density, and pressure velocity in calculating fluidization velocity. The review discusses the use of the Ergun equation and statistical techniques for predicting minimum fluidization velocity, noting that the pressure drop across the bed and the bed height are crucial factors. It also covers the application of tapered fluidization beds in industries like wastewater treatment and the use of correlation functions like the Wen and Yu correlation and the Chitister correlation. The review concludes that pressure velocity characteristics and the Ergun equation are effective techniques for predicting minimum fluidization velocity, emphasizing the influence of pressure on larger particles and the independence of dense phase voidage on pressure velocity.

LITERATURE REVIEW 0
Pressure Velocity Characteristics to
predict minimum Fluidization velocity

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Table of Contents
Literature review........................................................................................................................2
References..................................................................................................................................6

LITERATURE REVIEW 2
Literature review
In the last few years, there are numbers of authors provided their views on minimum
fluidization velocity and identified the characteristics of the pressure-velocity. This literature
review focuses on the fluidization velocity and analyses the role of pressure velocity
characteristics for predicting the velocity of fluidization.
According to Jiliang, Xiaoping and, Daoyin, (2013) the least fluidization velocity may be
calculated with the help of characteristics parameters, for example, drag coefficient,
viscosity, density and pressure velocity [1]. This paper identified that the minimum value of
fluidization velocity can be evaluated by a plotting a chart between weight drop and
superficial velocity. The author used the effective Ergun equation as a starting point for
predicting the minimum velocity of the fluidization. It is analysed that to distinguish the
effective relation to predicting the smallest velocity of the fluidization, a sound statistical
process is very important that has the ability for providing the appropriate fluidization
velocity. Kozanoglu, Chanes and, Jean, (2002) argued that for defining the smallest
fluidization velocity the fundamental concept of statistical technique can be used [2]. In this
journal paper, the authors suggested that there are four equations can be used for predicting
the lowest fluidizations velocities which are described below:
It is observed that the pressure drop crossways the best can be amplified with the help of the
Ergun equation which also provides the minimum value of fluidization velocity. The authors

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analysed that when the value of gas velocity is large enough which the drag power on the
atoms then the divan becomes fluidized. This point is distinct as the smallest fluidization
velocity and it is denoted as Umf. A recent study conducted by the Li, et al., (2013) identified
that the in the field of fluidization the larger gas velocities are not able to produce the large
pressure drop because at this stage the pressure drop is very slow related to the weight of the
suspended bed [3]. Moreover, the authors evaluated that the minimum value of fluidization
velocity may be evaluated by identifying the pressure drop transversely the bed and
calculating the height of the bed. The below equation shows the worth of pressure drop across
the bed which can help for finding the smallest amount of fluidization velocity.
In this research paper, the authors conducted a literature review in order to understand the
concept of fluidization and predict the minimum fluidization velocity. This paper provided
less information about the pressure-velocity which creates a research gap between the
information and research topic. This literature review reduces such kind of gaps and
drawbacks of previous studies by providing an in-depth analysis of the fluidization velocity.
According to Lu, et al., (2013) due of pressure velocity characteristics tapered fluidization
beds have used in many business industries such as wastewater treatment, coating nuclear
fuel substrates and so on [4]. It is identified that the pressure-velocity has the ability for
predicting the smallest fluidization velocity and provide complete information about the
pressure drop.
In this paper, the authors identified the key factor which impacts on the fluidization velocity
and pressure drop. Mohanta, et al., (2012) developed and implemented a theoretical
framework for the smallest fluidization speed and pressure droplet in the crowded bed atoms
for a solid system [5]. After analysing this journal paper it has found that the smallest
fluidization velocity is defined as a state where the drag on the particles is equal to the gravity
force. For predicting the lowest fluidization velocity at various pressure velocity
characteristics, an extensive experimental process has been carried out by the authors.
The researchers suggested that the smallest fluidisation velocity may be calculated with the
help of three correlation functions which includes Ergun equation, Wen and Yu correlation
and chitister correlation. Oliveira, Cardoso and Ataíde, (2013) conducted a research paper

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and also performed an untried process for predicting the smallest fluidization velocity by
using characteristics of pressure velocity [6]. The experimental setups were performed in a
pressurized bed and fluidized in the air at the room temperature. From this paper it is
analysed that the smallest fluidization velocity is completely based on the Ergun equation
which is given as:
The authors concluded that the pressure influence on the smallest fluidization velocity is
more pronounced for the huge particles. Moreover, the pressure-velocity characterization
effective predicts the minimum fluidization velocity in an effective manner and the dense
phase voidage does not depend on the value of pressure velocity. Olowson and Almstedt,
(1991) suggested that the spherical multi-particle model can be used for predicting the value
of fluidization velocity and it has the ability for finding the relation between the gas velocity
and pressure drop [7]. The researchers identified and predicted that the lowest value of
fluidization velocity depends on the pressure drop and the velocity of the pressure.
It is observed that the pressure-velocity characteristics are more accurate and quite high for
predicting the fluidization velocity. In which a model was developed by the authors and
tested with data or information reported by the previous studies. As compared to the previous
papers Olowson and Almstedt, (1991) provided in-depth analysis about fluidization velocity
and determined the smallest fluidization velocity and large pressure drip in an effective
manner. Moreover, the authors also reduced the gaps and supported their arguments with
evidence. According to Singh and Roy, (2005) the term minimum fluidization velocity refers
to the effective parameter which can be used for determining the design and operations of
fluidized beds [8].
The authors conducted research and adopted binary solid method along with the pressure-
velocity characteristics in order to predict the lowest velocity of the fluidization. After
analysing this paper it is identified that the least fluidization velocity may be found by
associating the gravity drop crossways the secure crowded bed and using the Ergun equation.
Therefore, it is analysed that most of the authors provided complete information about

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smallest fluidization velocity and obtained the similar conclusion that is pressure velocity
characteristics and Ergun equation both are appropriate techniques for predicting minimum
fluidization velocity.

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References
[1]. M., Jiliang, C. Xiaoping and, L., Daoyin, “Minimum fluidization velocity of particles
with wide size distribution at high temperatures,” Powder technology, vol. 235, no. 2,
pp.271-278, 2013.
[2]. B.U., Kozanoglu, J.W., D.G. Changes and, J.S., Jean, “Hydrodynamics of large
particle fluidization in reduced pressure operations: an experimental study,” Powder
technology, vol. 125, no. 1, pp.55-60, 2002.
[3]. J., Li, Z., Cheng, Y., Fang, H., Wang, W., Nie, J. Huang and, Y., Wang, “Minimum
and terminal velocity in fluidization of coal gasification materials and coal blending
of gasification under pressure,” Fuel, vol. 110, no. 16, pp.153-161, 2013.
[4]. Y., Lu, L., Zhao, Q., Han, L., Wei, X., Zhang, L. Guo and, J., Wei, “Minimum
fluidization velocities for supercritical water fluidized bed within the range of 633–
693 K and 23–27 MPa,” International Journal of Multiphase Flow, vol. 49, no. 2,
pp.78-82, 2013.
[5]. S., Mohanta, A.B., Daram, S. Chakraborty and, B.C., Meikap, “Characteristics of
minimum fluidization velocity for magnetite powder used in an air dense medium
fluidized bed for coal beneficiation,” Particle & Particle Systems
Characterization, vol. 29, no. 4, pp.228-237, 2012.
[6]. T.J.P., Oliveira, C.R. Cardoso and, C.H., Ataíde, “Bubbling fluidization of biomass
and sand binary mixtures: Minimum fluidization velocity and particle
segregation,” Chemical Engineering and Processing: Process Intensification, vol. 72,
no. 6, pp.113-121, 2013.
[7]. P.A. Olowson and, A.E., Almstedt, “Influence of pressure on the minimum
fluidization velocity, "Chemical Engineering Science, vol. 46, no. 2, pp.637-640,
1991.
[8]. R.K. Singh and, G.K., Roy, “Prediction of minimum bubbling velocity, fluidization
index and range of particulate fluidization for gas-solid fluidization in cylindrical and
non-cylindrical beds,” Powder Technology, vol. 159, no. 3, pp.168-172, 2005.