GROUP 5 FINAL LAB 4 Fluidized Beds
Fluidized Beds
Fluidized Beds
University of Illinois
Flow Diagram of Generic Fluidized Bed (Towler 397)
High velocity fluid and small solid particle packing are the key features of a fluidized bed reactor. The resulting fluid-particle mixture behaves as a fluid and allows for ample contact between the fluid and the solid particles. These properties of fluidized bed reactors make them ideal reactors for many types of reactions including catalytic driven reactions. In this lab fluidized bed reactors will be modeled using sand and silica as the solid packing and air as the high velocity fluid.
Unit Operations ChE 382 Group 5
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
1
Spring 2011 4/16/2020
Fluidized Beds
Final Lab Report
Unit Operations II Lab 4
April 16, 2020
Group 5
Andrew Duffy
Daniyal Qamar
Jeff Tyska
Bernard Hsu
Ryan Kosak
Tomi Damo
Alex Guerrero
University of Illinois
Unit Operations ChE 382 Group 5
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
2
Spring 2011 4/16/2020
Fluidized Beds
Contents
University of Illinois
Unit Operations ChE 382 Group 5
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
3
Spring 2011 4/16/2020
Fluidized Beds
1.
Summary
University of Illinois
The purpose of this lab was to measure the effects of superficial velocity and particle size on the pressure drop in a fluidized bed reactor. Fluidization occurs in the bed when the superficial velocity has been reached and that the particles in the bed become fully suspended and thus the fluid-particle mixture can then act as a fluid itself (Fluidized Beds). Fluidization allows for virtually uniform temperature distributions even when highly exothermic reactions are occurring, and since the solid particles are often used to catalyze the reaction occurring within the column, fluidization also allows for intimate contact between reactants and catalytic particles as well as uniform mixing.
Two trials were run for “Sand 1” which had a particle size average of 300 microns. Two trials were run for “Sand 2” which had an average particle size of 507.5 microns. The first trial was for increasing flow rate of sand and the second trial was for decreasing flowrate of sand. One trial was run for silica at 72ºF and two trials were run for silica at 90ºF. With measurements of the column internal diameter, cross sectional area of bed, max flowrate of the right and left rotameters, the density and viscosity of air as in Table 6.1, the pressure drop throughout the column in each trial was determined. In all trials, the pressure drop was plotted against the superficial velocity. The experimental fluidization velocity occurs when the pressure drop no longer increases for increasing superficial velocities.
However, the tabulate data is for the theoretical fluidization velocity, which was calculated with the density of air. For the first two trials that were run with Sand 1, the theoretical fluidization velocities were found to be 0.00132 m/s for each. For trials 3 and 4 for Sand 2, the theoretical fluidization velocity was found to be 0.00257 m/s for both. It makes physical sense that for both trials 1 and 2 and for trials
3 and 4 that the theoretical fluidization velocities are the same since the trials were run under the same conditions, except one was with increasing flowrates and the other trial was with decreasing flowrates.
Unit Operations ChE 382 Group 5
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
4
Spring 2011 4/16/2020
Fluidized Beds University of Illinois
Trials 3 and 4 show a larger discrepancy (see Graph 6.2) between the experimental fluidization velocities.
In all trials, the anticipated results were proven correct: pressure drop increased as superficial velocity increased. It was also anticipated that there would be a point at which the pressure drop would no longer rise for increases in superficial velocities. Between Sand 1 and Sand 2, Sand 2, which had a larger average particle size, experienced a larger maximum pressure at ~0.140 psi while Sand 1 had a maximum pressure drop of ~0.15 psi. Silica, which had the same average particle size as Sand 2 experienced the largest pressure drop at just over 0.200 psi for trials 5, 6, and 7. Increasing the temperature of the bed from 72ºF to 90ºF, as in trials 6 and 7, had virtually no effect on the pressure drop throughout the column. It should be noted that for trials 6 and 7 that a higher flowrate, and thus a higher superficial velocity, was not tested, as shown in Graph 6.4. However, this should not have been a problem as the pressure drop had already leveled off after 0.100 m/s superficial velocity.
As with every experiment, there were sources of error that ranged from human inaccuracy to apparatus faults. These faults include error in measuring the pressure drop at higher air flow rates due to manometer fluctuations, holes and leaks throughout the system skewing the pressure drop, and human error in measuring the bed height.
Unit Operations ChE 382 Group 5
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
5
Spring 2011 4/16/2020
Fluidized Beds
2.
Results
University of Illinois
In this lab the amount of air through a column with a certain level of sand/silica was increased to test the pressure drop in the column, and to see if the minimum fluidization velocity could be found.
From the data gathered, the settling velocity was also found, along with the ratio of setting velocity / fluidization velocity. A trial for silica was done with a different temperature, to see if a change in the density of air would have an effect on the fluidization and settling velocities. From the data in tables 5,
6, 9, 10, 13, 16, and 17 , it can be seen that the settling velocity was always much higher than the fluidization velocity, meaning that the particles fell faster than they rose. From the two different sand particle sizes, it seems like the settling velocity: fluidization velocity increases as particle size increases, however trials with more than 2 trials will need to be done to confirm this trend.
Trials 1 and 2: Sand 1 (Avg. 300 microns)
0,120
0,100
0,080
0,060
0,040
0,020
0,000
0,000E+00 1,000E-01 2,000E-01 3,000E-01 4,000E-01 5,000E-01
Superficial Velocity (m/s)
Trial 1: Increasing
Flow Rate Sand 1
Trial 2: Decreasing
Flow Rate Sand 1
Graph 1: Superficial velocity verses pressure drop of trials 1 and 2 (Sand 1)
For the first trial with sand (average of 300 microns), it is easy to see that the fluidization velocity occurred at 40 percent of the maximum air flow rate (about .19 meters per second), since that is where the pressure drop started to be independent of the air flow rate. This matches the observations
6
Unit Operations ChE 382 Group 5
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
Spring 2011 4/16/2020
Fluidized Beds University of Illinois in this lab where a significant amount of bubbling at this flow rate was observed. This chart also indicates that the minimum fluidization velocity is independent whether or not the air flow rate is being increased or decreased.
Trials 3 and 4: Sand 2 (Avg. 507.5 microns)
0,160
0,140
0,120
0,100
0,080
0,060
0,040
0,020
0,000
0,000E+00 1,000E-01 2,000E-01 3,000E-01 4,000E-01 5,000E-01
Superficial Velocity (m/s)
Trial 3:
Increasing Flow
Rate Sand 2
Graph 2: Superficial velocity verses pressure drop of trials 3 and 4 (Sand 2)
This graph depicts that the fluidization velocity for sand with a higher particle size than the initial trials (507.5 micron average) depends on whether or not the air flow rate is increasing or decreasing. After increasing the air flowrate, the fluidization occurred at about 0.19 meters per second, similar to the trials with the smaller particle size. In the trial where the flowrate was observed, however, the minimum fluidization velocity was not as well defined, and occurred at a higher flowrate around
0.28 meters per second.
Unit Operations ChE 382 Group 5
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
7
Spring 2011 4/16/2020
Fluidized Beds University of Illinois
0,250
0,200
0,150
0,100
0,050
0,000
0,000
Trial 5: Increasing Flow Rate Silica at 72°F
0,100 0,200 0,300 0,400
Superficial Velocity (m/s)
0,500 0,600
Trial 5: Increasing
Flow Rate Silica at…
Graph 3: Superficial velocity verses pressure drop of trial 5 at 72°F (Silica)
For the first silica trial, the main goal was to see where the minimum fluidization velocity occurred, in order to compare it to the trial at a higher temperature. From this graph it can be seen that the fluidization point occurs around 0.12 meters per second, between the lowest and second lowest flow rates.
Trials 6 and 7: Silica at 90°F
0,250
0,200
0,150
0,100
0,050
0,000
0,000 0,050 0,100
Superficial Velocity (m/s)
0,150 0,200
Graph 4: Superficial velocity verses pressure drop of trials 6 and 7at 90°F (Silica)
Trial 6: Increasing Flow
Rate Silica at 90°F
Trial 7: Increasing Flow
Rate Silica at 90°F
Unit Operations ChE 382 Group 5
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
8
Spring 2011 4/16/2020
Fluidized Beds University of Illinois
From the following graph, the increase of temperature clearly affected the fluidization velocity of silica. Although it may seem at first like the fluidization for silica at a higher temperature occurred much more gradually, it should be noted that the axes of this graph were different than the one in the previous figure. Nonetheless, it does appear that a slightly smaller fluidization velocity was needed, around 0.1 m/s. To confirm this, trials should be done for silica at 72 o F between 0.8 and 1.6 meters per second, so that less estimation has to be used. From the graph of silica at 90 o F it can be seen that the minimum fluidization velocity does not depend on whether or not the velocity is being increased or decreased.
3.
Discussion
Data and observations obtained during this fluidized bed lab closely follow that of the expected results. Both sand and silica were used as the solid particles to be fluidized by high velocity air flows. The fluidizations of the bed can be observed in all trials at which the solid particles unsettle and can be mathematically treated as a fluid. The average particle diameter of sand used in trial 1 and 2 was 300 microns and trials 3 and 4 were 507.5 microns. The sand trails were carried out at room temperature. All silica trials were conducted with an average particle size of 507.5 microns with trial 5 carried out at room temperature and trials 6 and 7 at 90 o F.
The pressure drop vs. superficial velocity graphs for all seven trials exhibit a plateau trend similar to the example shown in graph 5.
Unit Operations ChE 382 Group 5
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
9
Spring 2011 4/16/2020
Fluidized Beds University of Illinois
.
Graph 5: Example of pressure drop vs. superficial velocity
During the initial period of increasing superficial velocity there is a large increase in the pressure drop across the reactor. In this range the particle bed is still settled and fluidization has not yet occurred.
The Ergun equation is still applicable to model this portion of the curve (Bird 186). Once the curve has reached its maximum pressure drop it will no longer increase with increasing superficial velocity. During this period the bed is fluidized and can be treated as a fluid (McCabe 333).
In trails 2 and 4 the pressure drop was measured as the superficial velocity is decreased.
Because the bed particles settle in a more compact state after fluidization a hysteresis is expected in the curves (Towler 380). The line of decreasing superficial velocity should be slightly lower that the line of increasing velocity. This trend was observed in trials 3 and 4 but not in trials 1 and 2. The absence of the correct hysteretic trend in trial 1 and 2 is most likely because the sand particles were very fine showing that a correlation between hysteretic behavior and particle size is present. Trails 1, 2, and 3 all had a minimum fluidized velocity of 0.19 m/s however, trial 4 displayed a minimum fluidized velocity of 0.28 m/s. In trial 4 the minimum velocity is not well defined and the possibility of measurement inaccuracy is present.
Unit Operations ChE 382 Group 5
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
10
Spring 2011 4/16/2020
Fluidized Beds University of Illinois
In trail 5 (silica at room temperature) it was observed that the minimum fluidization velocity occurred at 0.12 m/s. Trials 6 and 7 (silica at 90 o F) displayed a minimum fluidization velocity of 0.10 m/s. This decrease in minimum velocity with an increase in temperature can be explained by conductive heat transfer. As incoming air comes in contact with the hot silica particles heat is transferred to the air.
This increase in air temperature also increases its buoyancy which more readily caries the silica particles upward with it.
Observations of the bed height were also noted with increasing superficial velocity. In all seven trails no increase in bed height was observed until the minimum fluidization velocity was reached at which point the bed height increased with increasing velocity. Some slight bubbling was observed in the bed before the minimum fluidization velocity was reached however they were not sufficient enough to unseat the bed. As the air velocity was decreased the bed height bubbled less violently and decreased until settled.
4.
Conclusion
The purpose of this lab was to measure the effects of superficial velocity and particle size on the pressure drop in a fluidized bed reactor. Fluidization occurs in the bed when the superficial velocity has been reached and that the particles in the bed become fully suspended and thus the fluid-particle mixture can then act as a fluid itself. Fluidization allows for virtually uniform temperature distributions even when highly exothermic reactions are occurring, and since the solid particles are often used to catalyze the reaction occurring within the column, fluidization also allows for intimate contact between reactants and catalytic particles as well as uniform mixing.
Two trials were run for “Sand 1” which had a particle size average of 300 microns. Two trials were run for “Sand 2” which had an average particle size of 507.5 microns. The first trial was for
Unit Operations ChE 382 Group 5
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
11
Spring 2011 4/16/2020
Fluidized Beds University of Illinois increasing flow rate of sand and the second trial was for decreasing flowrate of sand. One trial was run for silica at 72ºF and two trials were run for silica at 90ºF. With measurements of the column internal diameter, cross sectional area of bed, max flowrate of the right and left rotameters, the density and viscosity of air as in Table 6.1, the pressure drop throughout the column in each trial was determined. In all trials, the pressure drop was plotted against the superficial velocity. The experimental fluidization velocity occurs when the pressure drop no longer increases for increasing superficial velocities.
However, the tabulate data is for the theoretical fluidization velocity, which was calculated with the density of air. For the first two trials that were run with Sand 1, the theoretical fluidization velocities were found to be 0.00132 m/s for each. For trials 3 and 4 for Sand 2, the theoretical fluidization velocity was found to be 0.00257 m/s for both. It makes physical sense that for both trials 1 and 2 and for trials
3 and 4 that the theoretical fluidization velocities are the same since the trials were run under the same conditions, except one was with increasing flowrates and the other trial was with decreasing flowrates.
Trials 3 and 4 show a larger discrepancy (see Graph 6.2) between the experimental fluidization velocities.
In all trials, the anticipated result occurred: pressure drop increased as superficial velocity increased. It was also anticipated that there would be a point at which the pressure drop would no longer rise for increases in superficial velocities. Between Sand 1 and Sand 2, Sand 2, which had a larger average particle size, experienced a larger maximum pressure at ~0.140 psi while Sand 1 had a maximum pressure drop of ~0.15 psi. Silica, which had the same average particle size as Sand 2 experienced the largest pressure drop at just over 0.200 psi for trials 5, 6, and 7. Increasing the temperature of the bed from 72ºF to 90ºF, as in trials 6 and 7, had virtually no effect on the pressure drop throughout the column. It should be noted that for trials 6 and 7 that a higher flowrate, and thus a higher superficial velocity, was not tested, as shown in Graph 6.4. However, this should not have been a problem as the pressure drop had already leveled off after 0.100 m/s superficial velocity.
12
Unit Operations ChE 382 Group 5
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
Spring 2011 4/16/2020
Fluidized Beds University of Illinois
As with every experiment, there were sources of error that ranged from human inaccuracy to apparatus faults. These faults include error in measuring the pressure drop at higher air flow rates due to manometer fluctuations, holes and leaks throughout the system skewing the pressure drop, and human error in measuring the bed height.
5.
References
Bird, R. Byron, Warren E. Stewart, and Edwin N. Lightfoot. Transport Phenomena. New York: J. Wiley,
2007. Print.
"Fluidized Beds." University of Illinois at Chicago - UIC. Web. 25 Jan. 2010.
< http://www.uic.edu/depts/chme/UnitOps/che381-2005f-frame.html
>.
Sinnott, Ray, and Gavin Towler. Chemical Engineering Design. Amsterdam: Elsevier, 2009. Print.
W.E. McCabe, J.C. Smith, and P. Harriott 2001. Unit Operations of Chemical Engineering, McGraw Hill,
New York.
Unit Operations ChE 382 Group 5
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
13
Spring 2011 4/16/2020
Fluidized Beds
6.
Appendix I: Data Tabulation/Graphs
University of Illinois
Trials 1 and 2: Sand 1 (Avg. 300 microns)
0,120
0,100
0,080
0,060
0,040
0,020
0,000
0,000E+00 1,000E-01 2,000E-01 3,000E-01 4,000E-01 5,000E-01
Superficial Velocity (m/s)
Trial 1: Increasing
Flow Rate Sand 1
Trial 2: Decreasing
Flow Rate Sand 1
Graph 1: Superficial velocity verses pressure drop of trials 1 and 2 (Sand 1)
Trials 3 and 4: Sand 2 (Avg. 507.5 microns)
0,160
0,140
0,120
0,100
0,080
0,060
0,040
0,020
0,000
0,000E+00 1,000E-01 2,000E-01 3,000E-01 4,000E-01 5,000E-01
Superficial Velocity (m/s)
Trial 3:
Increasing Flow
Rate Sand 2
Graph 2: Superficial velocity verses pressure drop of trials 3 and 4 (Sand 2)
Unit Operations ChE 382 Group 5
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
14
Spring 2011 4/16/2020
Fluidized Beds University of Illinois
0,250
0,200
0,150
0,100
0,050
0,000
0,000
Trial 5: Increasing Flow Rate Silica at 72°F
0,100 0,200 0,300 0,400
Superficial Velocity (m/s)
0,500 0,600
Trial 5: Increasing
Flow Rate Silica at…
Graph 3: Superficial velocity verses pressure drop of trial 5 at 72°F (Silica)
Trials 6 and 7: Silica at 90°F
0,250
0,200
0,150
0,100
0,050
0,000
0,000 0,050 0,100
Superficial Velocity (m/s)
0,150 0,200
Trial 6: Increasing Flow
Rate Silica at 90°F
Trial 7: Increasing Flow
Rate Silica at 90°F
Graph 4: Superficial velocity verses pressure drop of trials 6 and 7at 90°F (Silica)
Unit Operations ChE 382 Group 5
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
15
Spring 2011 4/16/2020
Fluidized Beds
Internal Diameter of Columns:
Cross Sectional Area of Bed:
Max Flow Rate (Left Rotameter):
10 cm
0.1 m
0.00785 m^2
220 L/min
0.00366667 m^3/s
Max Flow Rate (Right Rotameter): 13.4 CFM
0.00632257 m^3/s
Density of Air at 70°F:
Density of Air at 72°F:
Density of Air at 90°F:
1.2041 kg/m^3
1.1921 kg/m^3
1.1489 kg/m^3
Viscoisty of Air at 70°F:
Viscoisty of Air at 72°F:
Viscoisty of Air at 90°F:
1.842E-05 kg/m*s
1.847E-05 kg/m*s
1.896E-05 kg/m*s
Table 1: Constants used for calculations
Error
Ruler
Rotameter
Pressure
Heater
Graduated
Cylinder
Scale
±
±
±
±
±
0.5 cm
0.005 m
2 %
0.05 in H20
0.001 °F
±
±
0.5 mL
0.0001 g
Table 2: Errors for equipment used
University of Illinois
Error (± )
0.005
0.000025
7.3333E-05
0.00012645
Unit Operations ChE 382 Group 5
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
16
Spring 2011 4/16/2020
Sand 1
Fluidized Beds
350-250 Microns
Trial 1: Increasing Flow Rate
Density
Trial 2:
University of Illinois
2.66428571 g/mL
Decreasing Flow Rate
Bed Height: 13.75 cm Bed Height: 13.75 cm
Flow Rate Pressure
(% of CFM) (inH2O)
0
10
20
30
0.00
1.15
2.40
off
Observations nothing nothing
40
2.80
bubbles slight surface
2.90
bubbles
50
60
70
80
90
100
3.00
3.00
3.00
in. dia. Bubbles agitated bubbles
3.05
fluidization
3.05
fluidization
3.05
fluidization turbulent bubbling
Flow Rate
(% of CFM)
100
90
80
70
60
50
40
30
20
10
0
Table 3: Trials 1 and 2 raw data
Pressure
(inH2O)
3.10
3.10
3.10
3.10
3.10
fluidization
3.10
fluidization
3.00
small bubbles
2.90
small bubbles
2.05
no bubbles
0.95
no bubbles
0.00
off
Observations violent bubbling chugging chugging chugging
Unit Operations ChE 382 Group 5
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
17
Spring 2011 4/16/2020
Fluidized Beds
Trial 1 and 2
University of Illinois
Error (± )
Average Particle Size:
Height of Bed:
Volume of Bed:
Density of Sand:
Bulk Density:
300 microns
0.0003 meters
13.75 cm
0.1375 m
0.00107938 m^3
2.66428571 g/mL
2664.28571 kg/m^3
1.99975279 g/mL
1999.75279 kg/m^3
0.00001
0.005
3.94E-05
0.09515306
95.1530615
0.07128566
71.2856607
Void Fraction: 0.24942255
Volume of Particles: 8.102E-04 m^3
Table 4: Trials 1 and 2 basic information
Trial 1: Increasing Flow Rate Sand 1
Flow Rate Flow Rate Flow Rate Error
% (m^3/s) (± )
0 0.000E+00 0.000E+00
0.1
0.2
0.3
0.4
0.5
3.667E-04
7.333E-04
1.100E-03
1.467E-03
1.833E-03
7.333E-06
1.467E-05
2.200E-05
2.933E-05
3.667E-05
0.6
0.7
0.8
0.9
1
2.200E-03
2.567E-03
2.933E-03
3.300E-03
3.667E-03
4.400E-05
5.133E-05
5.867E-05
6.600E-05
7.333E-05
Pressure
(psi)
0.000
0.042
0.087
0.101
0.105
0.108
0.108
0.108
0.110
0.110
0.110
Pressure
Error
(± )
Superficial
Velocity
(m/s)
0.00E+00 0.000E+00
7.49E-05
1.56E-04
1.82E-04
1.89E-04
1.95E-04
4.671E-02
9.342E-02
1.401E-01
1.868E-01
2.335E-01
Superficial
Velocity
Error
(± )
0.000945952
0.001891904
0.002837856
0.003783808
0.00472976
1.95E-04
1.95E-04
1.99E-04
1.99E-04
1.99E-04
2.803E-01 0.005675712
3.270E-01 0.006621664
3.737E-01 0.007567616
4.204E-01 0.008513568
4.671E-01 0.00945952
Fluidization Velocity (Min):
Settling Velocity:
Settling/Fluidization:
0.1320 m/s
5.322 m/s
40.309 ratio
Error: (±)
Error: (±)
Error: (±)
Table 5: Trial 1 calculations with error
18
Unit Operations ChE 382 Group 5
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
0.01258592
0.0103
0.3145
3.2733
Spring 2011 4/16/2020
Fluidized Beds
Trial 2: Decreasing Flow Rate Sand 1
Flow Rate
%
1
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
University of Illinois
Flow Rate Flow Rate ErrorPressure
(m^3/s) (± ) (psi)
3.667E-03 7.333E-05
3.300E-03 6.600E-05
0.112
0.112
2.933E-03 5.867E-05
2.567E-03 5.133E-05
2.200E-03 4.400E-05
1.833E-03 3.667E-05
0.112
0.112
0.112
0.112
1.467E-03 2.933E-05
1.100E-03 2.200E-05
7.333E-04 1.467E-05
3.667E-04 7.333E-06
0.108
0.105
0.074
0.034
0.000E+00 0.000E+00 0.000
Pressure
Error
(± )
2.02E-04
Superficial
Velocity
(m/s)
4.671E-01
Superficial
Velocity
Error
(± )
9.460E-03
4.204E-01 0.008513568
2.02E-04
2.02E-04
2.02E-04
2.02E-04
2.02E-04
1.95E-04
1.89E-04
1.34E-04
6.19E-05
3.737E-01 0.007567616
3.270E-01 0.006621664
2.803E-01 0.005675712
2.335E-01 0.00472976
1.868E-01 0.003783808
1.401E-01 0.002837856
9.342E-02 0.001891904
4.671E-02
0.00E+00 0.000E+00
0.000945952
Fluidization Velocity (Min):
Settling Velocity:
Settling/Fluidization:
0.1320 m/s
5.322 m/s
40.309 ratio
Error: (±)
Error: (±)
Error: (±)
Table 6: Trial 2 calculations with error
Sand 2 595-420 Microns Density 2.66428571
0.0010
0.3145
32.7334
Trial 3: Increasing Flow Rate Trial 4: Decrasing Flow Rate
Bed Height: 14.5 cm Bed Height: 14.5 cm
Flow Rate
(% of CFM)
0
10
20
30
Pressure Observations
(inH2O)
0.00
off
1.40
nothing
3.00
nothing
3.55
bubbles
Flow Rate Pressure
(% of CFM) (inH2O)
Observations
100 3.80
fluidization
90 3.70
violent bubbles
80 3.70
violent bubbles
70 3.70
violent bubbles
40
50
60
70
80
90
100
3.70
bubbles
3.80
more bubbles
3.80
more bubbles
3.80
more bubbles
3.80
violent bubbles
3.80
violent bubbles
3.80
violent bubbles
Table 7: Trials 3 and 4 raw data
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Unit Operations ChE 382 Group 5
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60 3.70
bubbles
50 3.60
bubbles
40 3.40
small bubbles
30 2.80
small bubbles
20 1.90
no bubbles
10 0.90
nothing
0 0.00
off
Spring 2011 4/16/2020
Fluidized Beds
Trial 3 and 4
University of Illinois
Error (± )
Average Particle Size:
Height of Bed:
507.5 microns
0.0005075 meters
14.5 cm
0.145 m
0.00001
0.005
3.9417E-05 Volume of Bed:
Density of Sand:
Bulk Density:
0.00113825 m^3
2.66428571 g/mL
2664.28571 kg/m^3
2.0797429 g/mL
2079.7429 kg/m^3
0.21939945
0.09515306
95.1530612
0.07128566
71.2856607
0.01086053
Void Fraction:
Volume of Particles: 0.00088852 m^3
Table 8: Trials 3 and 4 basic information
Trial 3: Increasing Flow Rate Sand 2
Flow Rate Flow Rate Flow Rate Error
% (m^3/s) (± )
0
0.1
0.2
0.3
0.000E+00
3.667E-04
7.333E-04
1.100E-03
0.000E+00
7.333E-06
1.467E-05
2.200E-05
0.4
0.5
0.6
0.7
0.8
0.9
1
1.467E-03
1.833E-03
2.200E-03
2.567E-03
2.933E-03
3.300E-03
3.667E-03
2.933E-05
3.667E-05
4.400E-05
5.133E-05
5.867E-05
6.600E-05
7.333E-05
Pressure
(psi)
0.000
0.051
0.108
0.128
0.134
0.137
0.137
0.137
0.137
0.137
0.137
Pressure
Error
(± )
Superficial
Velocity
(m/s)
Superficial
Velocity
Error
(± )
0.00E+00 0.000E+00
9.12E-05 4.671E-02 0.000945952
1.95E-04
2.31E-04
9.342E-02
1.401E-01
0.001891904
0.002837856
2.41E-04
2.48E-04
2.48E-04
2.48E-04
2.48E-04
2.48E-04
2.48E-04
1.868E-01
2.335E-01
2.803E-01
0.003783808
0.00472976
0.005675712
3.270E-01 0.006621664
3.737E-01 0.007567616
4.204E-01 0.008513568
4.671E-01 0.00945952
Fluidization Velocity (Min):
Settling Velocity:
Settling/Fluidization:
0.2572 m/s
15.839 m/s
61.594 ratio
Error: (±)
Error: (±)
Error: (±)
Table 9: Trial 3 calculations with error
20
Unit Operations ChE 382 Group 5
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0.0171
0.6997
4.2067
Spring 2011 4/16/2020
Fluidized Beds
Trial 4: Decreasing Flow Rate Sand 2
Flow Rate
%
1
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
University of Illinois
Flow Rate
(m^3/s)
Flow Rate
Error
(± )
3.667E-03 7.333E-05
3.300E-03 6.600E-05
2.933E-03 5.867E-05
2.567E-03 5.133E-05
2.200E-03 4.400E-05
1.833E-03 3.667E-05
1.467E-03 2.933E-05
1.100E-03 2.200E-05
7.333E-04 1.467E-05
3.667E-04 7.333E-06
0.123
0.101
0.069
0.032
0.000E+00 0.000E+00 0.000
Pressure
(psi)
0.137
0.134
0.134
0.134
0.134
0.130
Pressure
Error
(± )
2.48E-04
2.41E-04
2.41E-04
2.41E-04
Superficial
Velocity
(m/s)
Superficial
Velocity
Error
(± )
4.671E-01 0.00945952
4.204E-01 0.008513568
3.737E-01 0.007567616
3.270E-01 0.006621664
2.41E-04
2.35E-04
2.22E-04
1.82E-04
2.803E-01 0.005675712
2.335E-01 0.00472976
1.868E-01 0.003783808
1.401E-01 0.002837856
1.24E-04
5.86E-05
9.342E-02
4.671E-02
0.00E+00 0.000E+00
0.001891904
0.000945952
Fluidization Velocity (Min):
Settling Velocity:
Settling/Fluidization
0.2572 m/s
15.839 m/s
61.594 ratio
Error: (±)
Table 10: Trial 4 calculations with error
Silica 595-420
Error: (±)
Error: (±) microns
0.0017
0.6997
42.0672
Trial 5:
Bed Height
Temperature:
Increasing Flow Rate
23.7 cm
72 °F
Flow Rate Pressure
(% of CFM) (inH2O)
0 0.00
off
Observations
10
20
30
40
50
60
5.10
6.10
6.20
6.20
6.20
6.20
none chugguing violent chugging bed lift, turbulent fluidization violent bubbling
Table 11: Trial 5 raw data
Unit Operations ChE 382 Group 5
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21
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Fluidized Beds
Trial 5
University of Illinois
Error (± )
Average Particle Size:
Height of Bed:
507.5 microns
0.0005075 meters
23.7 cm
0.237 m
0.00001
0.005
3.9695E-05 Volume of Bed:
Density of Silica:
Bulk Density:
0.00186045 m^3
2.948 g/mL
2948 kg/m^3
1.29583981 g/mL
1295.83981 kg/m^3
0.56043426
0.10528571
105.285714
0.07128566
71.2856607
0.03675756
Void Fraction:
Volume of Particles: 0.00081779 m^3
Table 12: Trial 5 basic information
Trial 5: Increasing Flow Rate Silica at 72° F
Flow Rate Flow Rate Flow Rate Error
% (m^3/s) (± )
0
0.1
0.2
0.3
0.4
0.5
0.6
0.000E+00
6.323E-04
1.265E-03
1.897E-03
2.529E-03
3.161E-03
3.794E-03
0.000E+00
1.265E-05
2.529E-05
3.794E-05
5.058E-05
6.323E-05
7.587E-05
Pressure
(psi)
0.000
0.184
0.220
0.224
0.224
0.224
0.224
Pressure
Error
(± )
0.00E+00
3.32E-04
3.97E-04
4.04E-04
4.04E-04
4.04E-04
4.04E-04
Superficial
Velocity
(m/s)
0.000
0.081
0.161
0.242
0.322
0.403
0.483
Superficial
Velocity
Error
(± )
0.001631139
0.003262279
0.004893418
0.006524558
0.008155697
0.009786837
Fluidization Velocity:
Settling Velocity:
Settling/Fluidization:
0.4728 m/s
9.839 m/s
20.810 ratio
Error: (±)
Error: (±)
Error: (±)
Table 13: Trial 5 calculations with error
0.0377
0.6067
1.7379
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Silica
Fluidized Beds
595-420
Trail 6: microns
Increasing Flow Rate
Silica
Trail 7:
University of Illinois
595-420 microns
Decreasing Flow Rate
Bed Height:
Temperature:
23.7 cm
90 °F
Bed Height:
Temperature:
23.7 cm
90 °F
Flow Rate
(% of CFM)
0
5
10
12
14
16
18
20
Pressure
(inH2O)
Observations
0.00
off
3.70
nothing
5.60
nothing
6.00
small bubbles
6.00
bubbles
6.00
chugging
6.10
chugging
6.10
fluidization
Flow Rate
(% of CFM)
20
18
16
14
12
10
5
0
Table 14: Trials 6 and 7 raw data
Pressure
(inH2O)
6.10
6.10
6.05
6.00
5.60
4.90
3.50
0.00
chugging chugging slight chugging bubbles nothing off
Observations fluidization fluidization
Trial 6 and 7 Error (± )
Average Particle Size:
Height of Bed:
Volume of Bed:
Density of Sand:
507.5 microns
0.0005075 meters
23.7 cm
0.237 m
0.00186045 m^3
2.948 g/mL
2948 kg/m^3
Bulk Density: 1.29583981 g/mL
1295.83981 kg/m^3
0.56043426
Void Fraction:
Volume of Particles: 0.00081779 m^3
Table 15: Trials 6 and 7 basic information
Unit Operations ChE 382 Group 5
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23
0.00001
0.005
3.9695E-05
0.10528571
105.285714
0.07128566
71.2856607
0.03675756
Spring 2011 4/16/2020
Fluidized Beds
Trial 6: Increasing Flow Rate Silica at 90° F
University of Illinois
Flow Rate Flow Rate Flow Rate Error
% (m^3/s) (± )
0.00
0.05
0.10
0.12
0.000E+00
3.161E-04
6.323E-04
7.587E-04
0.000E+00
6.323E-06
1.265E-05
1.517E-05
0.14
0.16
0.18
0.20
8.852E-04
1.012E-03
1.138E-03
1.265E-03
1.770E-05
2.023E-05
2.276E-05
2.529E-05
Fluidization Velocity:
Settling Velocity:
Settling/Fluidization:
0.4606 m/s
9.585 m/s
20.810 ratio
Error: (±)
Error: (±)
Error: (±)
0.0415
0.5911
1.9525
Table 16: Trial 6 calculations with error
Trial 7: Increasing Flow Rate Silica at 90° F
Flow Rate
%
0.20
0.18
0.16
0.14
0.12
0.10
0.05
0.00
Flow Rate
(m^3/s)
Flow Rate
Error
(± )
1.265E-03 2.529E-05
1.138E-03 2.276E-05
1.012E-03 2.023E-05
8.852E-04 1.770E-05
7.587E-04 1.517E-05
6.323E-04 1.265E-05
Pressure
(psi)
0.220
0.220
0.218
0.217
0.202
0.177
3.161E-04 6.323E-06 0.126
0.000E+00 0.000E+00 0.000
Pressure
Error
(± )
3.97E-04
3.97E-04
3.94E-04
3.91E-04
3.65E-04
3.19E-04
2.28E-04
0.00E+00
Superficial
Velocity
(m/s)
0.161
0.145
0.129
0.113
0.097
0.081
0.040
0.000
Superficial
Velocity
Error
(± )
0.003262279
0.002936051
0.002609823
0.002283595
0.001957367
0.001631139
0.00081557
Fluidization Velocity:
Settling Velocity:
Settling/Fluidization:
Pressure
(psi)
0.000
0.134
0.202
0.217
0.217
0.217
0.220
0.220
Pressure
Error
(± )
0.00E+00
2.41E-04
3.65E-04
3.91E-04
3.91E-04
3.91E-04
3.97E-04
3.97E-04
Superficial
Velocity
(m/s)
0.000
0.040
0.081
0.097
0.113
0.129
0.145
0.161
Superficial
Velocity
Error
(± )
0.00081557
0.001631139
0.001957367
0.002283595
0.002609823
0.002936051
0.003262279
0.4606 m/s
9.585 m/s
20.810 ratio
Error: (±)
Error: (±)
Error: (±)
Table 17: Trial 7 calculations with error
0.041465873
0.591079233
1.952539398
Unit Operations ChE 382 Group 5
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Fluidized Beds
7.
Appendix II: Error Analysis
University of Illinois
There were a lot of sources of errors during the experiment; most of the errors came from the equipment and human measurement. All the equipment used was precise to a certain degree and after that an estimate was made. The error measured for each of the instrument is stated in table 18 below.
Equipment
Meter Scale
Air rotameter 1 (Sand Column)
Air rotameter 2 (Silica Column)
Error
± 0.05 cm
± 2% of max airflow
± 1% of max air flow
Manometer (U tube)
Graduated Cylinder
± 0.05 inches of H
2
O
± 0.5 ml
Temperature Probe
Mass Scale
Table 18: Equipment Errors
± 0.001 ºF
± 0.0001 g
There was a large error in measuring the pressure drop at higher air flow rates. As the air flow was increased in each of the trials and the bed reached fluidization there was a point where the manometer readings started fluctuating by differences of 1 inch H
2
O. For example this fluctuation occurred when the air flow rate through the sand column reached 50% of the maximum value. At this flow rate the water level in the manometer was fluctuating between 2.5 and 3.5 in H
2
O. An estimate had to be made and this consequently contributed to the error in calculations.
The laboratory equipment also contributed to the error in the calculations. There were several holes and leaks in the column that pressure could escape through. In the sand column for example one of the fittings was broken and this point was before the outlet pressure valve was situated, so some of
Unit Operations ChE 382 Group 5
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25
Spring 2011 4/16/2020
Fluidized Beds University of Illinois the pressure would have escaped through this hole. On the silica bed there was a leak where the temperature probe was situated.
There was also room of error when the bed height measurement was taken. Since there were no numbers on the column itself a meter rule was used. This measurement was a rough measurement as well. The accuracy of the sand size was another possible source of error. Although the group was very careful there were some sieve trays with holes larger than the diameter specified this let in sand grains larger than they are supposed to be and thus introduced error in the calculations.
The specific error with each calculation is listed in the data tables 1 through 17. The general trend was as expected: as the number increases the error associated with it increased as well. For example in trial 1 for sand the flow rate error increased from 0 to 7.33x10
-5 as the flow rate increased from 0 to 100 % of the maximum value.
Unit Operations ChE 382 Group 5
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26
Spring 2011 4/16/2020
Fluidized Beds
8.
Appendix III: Sample Calculations
University of Illinois
Cross Sectional Area of the Bed:
𝐴 = 𝜋 ∗ 𝑟
2
𝐴 = 𝜋 ∗ (0.1 𝑚)
2
= 0.00785 𝑚
2
Volume of the Bed:
𝑉 = 𝐴 ∗ 𝐿
𝑉 = (0.00785 𝑚 2 ) ∗ (0.1375 𝑚) = 0.00107 𝑚 3
Void Fraction: 𝜀 = 1 − 𝜌 𝑏 𝜌 𝑝 𝜀 = 1 −
1999.75
2664.28 𝑘𝑔 𝑚 3 𝑘𝑔 𝑚 3
= 0.249
Volume of Particles:
𝑉 𝑝
= (1 − 𝜀) ∗ 𝐴 ∗ 𝐿
𝑉 𝑝
= (1 − 0.249) ∗ (0.00785 𝑚
2 ) ∗ (0.1375 𝑚) = 8.102𝐸 −04
𝑚
3
Flow Rate:
Pressure Conversion:
𝑄 = 𝑅𝑜𝑡𝑎𝑚𝑒𝑡𝑒𝑟 𝑀𝑎𝑥 ∗ 𝐹𝑙𝑜𝑤 %
𝑄 = 3.66𝐸
−03 𝑚
3 𝑠
∗ 0.10 = 3.66𝐸
−04 𝑚
3 𝑠 𝑝𝑠𝑖 = 𝑖𝑛 𝐻
2
𝑂 ∗ 0.0361
𝑝𝑠𝑖 𝑖𝑛 𝐻
2
0 𝑝𝑠𝑖
1.15 𝑖𝑛 𝐻
2
𝑂 ∗ 0.0361
𝑖𝑛 𝐻
2
0
= 0.042 𝑝𝑠𝑖
Unit Operations ChE 382 Group 5
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
27
Spring 2011 4/16/2020
Fluidized Beds
Superficial Velocity:
University of Illinois 𝑣 =
𝑄
𝐴 𝑣 =
3.66𝐸 −04 𝑚
0.00785 𝑚 𝑠
2
3
= 4.671𝐸 −02 𝑚 𝑠
Fluidization Velocity:
𝑉 𝑓
=
(𝜌 𝑝
− 𝜌 𝑓
) ∗ 𝑔 ∗ 𝐷
2 𝑝
150 ∗ 𝜇
∗ 𝜀
3
1 − 𝜀
𝑉 𝑓
=
(1999.75
𝑘𝑔 𝑚 3
− 1.2
𝑘𝑔 𝑚 3
) ∗ 9.81
𝑚 𝑠 2
150 ∗ 1.84𝐸 −05 𝑘𝑔 𝑚 ∗ 𝑠
∗ (0.0003 𝑚)
2
0.249
3
∗
1 − 0.249
= 0.132 𝑚 𝑠
Settling Velocity:
𝑉
𝑆𝑒𝑡𝑡𝑙𝑖𝑛𝑔
=
(𝜌 𝑝
− 𝜌 𝑓
) ∗ 𝑔 ∗ 𝐷 2 𝑝
18 ∗ 𝜇
𝑉 𝑠𝑒𝑡𝑡𝑙𝑖𝑛𝑔
=
(1999.75
𝑘𝑔 𝑚 3
− 1.2
𝑘𝑔 𝑚 3
) ∗ 9.81
18 ∗ 1.84𝐸 −05 𝑚 𝑠 2 𝑘𝑔 𝑚 ∗ 𝑠
∗ (0.0003 𝑚)
2
= 5.322
𝑚 𝑠
Settling Velocity and Fluidization Velocity Ratio:
𝑅𝑎𝑡𝑖𝑜 =
𝑉
𝑆𝑒𝑡𝑡𝑙𝑖𝑛𝑔
𝑉 𝑓
𝑅𝑎𝑡𝑖𝑜 =
5.322
0.132
𝑚 𝑠 𝑚 𝑠
= 40.31
Unit Operations ChE 382 Group 5
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Fluidized Beds
9.
Appendix IV: Individual Team Contributions
Name: Ryan Kosak
Operator (Both Lab
Days)
Pre-Lab Editing
Final Lab Editing
Summary
Introduction
Literature Review /
Theory
Apparatus
Materials and Supplies
Procedure
Anticipated Results
Results
Discussion
Conclusion
References
Graphs
Data Tabulation /
Error Analysis
Sample Calculations
Job Safety Analysis
Power Point
Presentation
Total
Time (Hours)
7.0
1.0
0
0
0
3.0
0
0
0
0
5.0
0
0
0
0
1.5
1.5
0
0
19.0
Days)
Name: Andrew Duffy
Operator (Both Lab
Pre-Lab Editing
Final Lab Editing
Summary
Introduction
Literature Review /
Time (Hours)
Unit Operations ChE 382 Group 5
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
3.5
3
0
0
0
0
29
University of Illinois
Description
Missed one lab day due to illness.
Assembled and edited
Spring 2011 4/16/2020
Description
Present Both Days
Wrote Section
Wrote Section
Preformed Error
Calculations
Wrote Section
Fluidized Beds
Theory
Apparatus
Materials and Supplies
Procedure
Anticipated Results
Results
Discussion
Conclusion
Graphs
References
Data Tabulation /
Error Analysis
Sample Calculations
Job Safety Analysis
Power Point
Presentation
Total
Name: Bernard Hsu
Operator (Both Lab
Days)
Pre-Lab Editing
Final Lab Editing
Summary
Introduction
Literature Review /
Theory
Apparatus
Materials and Supplies
Procedure
Anticipated Results
Results
Discussion
Conclusion
Graphs
References
Data Tabulation /
Error Analysis
Sample Calculations
Job Safety Analysis
Power Point
Presentation
Total
Time (Hours)
7
0
0.5
2
1.5
0
0
0
0.5
0
11.5
Unit Operations ChE 382 Group 5
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
30
0
0
0
0
0
0
0
0
0
0
0
0
0
9
0
0
0
0
0
2.5
0
0
0
University of Illinois
Wrote section
Description
Present for all of both lab periods
Wrote section
Wrote section
Wrote section
Spring 2011 4/16/2020
Fluidized Beds
Name: Daniyal Qamar
Operator (Both Lab
Days)
Pre-Lab Editing
Final Lab Editing
Summary
Introduction
Literature Review /
Theory
Apparatus
Materials and Supplies
Procedure
Anticipated Results
Results
Discussion
Conclusion
Graphs
References
Data Tabulation /
Error Analysis
Sample Calculations
Job Safety Analysis
Power Point
Presentation
Total
Days)
Name: Jeff Tyska
Operator (Both Lab
Theory
Pre-Lab Editing
Final Lab Editing
Summary
Introduction
Literature Review /
Apparatus
Materials and Supplies
Procedure
Anticipated Results
Results
Time (Hours)
Unit Operations ChE 382 Group 5
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
7
0
0
0
0
0
1
1
0
0
2
31
Time (Hours)
7
0
0
0
0
0
2
0
0
0
0
0
0
0
0
2
0
0
0
11
University of Illinois
Description
Present for all of both lab periods
Wrote Section
Wrote Section
Description
Present for all of both lab periods
Wrote Section
Wrote Section
Wrote Section
Spring 2011 4/16/2020
Fluidized Beds
Discussion
Conclusion
References
Data Tabulation /
Graphs
Error Analysis
Sample Calculations
Job Safety Analysis
Power Point
Presentation
Total
Name: Tom Damo
Operator (Both Lab
Days)
Pre-Lab Editing
Final Lab Editing
Summary
Introduction
Literature Review /
Theory
Apparatus
Materials and Supplies
Procedure
Anticipated Results
Results
Discussion
Conclusion
Graphs
References
Data Tabulation /
Error Analysis
Sample Calculations
Job Safety Analysis
Power Point
Presentation
Total
Unit Operations ChE 382 Group 5
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
32
Time (Hours)
7
0
0
0
0
0
0
0
1.5
0
0
0
0
0
0
0
0
0
2
10.5
0
0
0
0
0
0
0
0
11
University of Illinois
Description
Present for all of both lab periods
Wrote Section
Wrote Section
Spring 2011 4/16/2020
Fluidized Beds
Days)
Name: Alex Guerrero
Operator (Both Lab
Pre-Lab Editing
Final Lab Editing
Summary
Introduction
Literature Review /
Theory
Apparatus
Materials and Supplies
Procedure
Anticipated Results
Results
Discussion
Conclusion
References
Graphs
Data Tabulation /
Error Analysis
Sample Calculations
Job Safety Analysis
Power Point
Presentation
Total
University of Illinois
Time (Hours)
7
0.5
2.5
0
0
2.5
0
0
0
0.5
0
0
0
0
0
0
0
0
0
13
Reviewed and made corrections.
Assembled final lab, and made corrections where needed.
Description
Present for all of both lab periods
Helped write this section.
Reviewed references to included in post lab.
Unit Operations ChE 382 Group 5
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
33
Spring 2011 4/16/2020
