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					Fluidized Bed                                                                           University of Illinois




                                     Fluidized Bed




                                         Picture courtesy of: EPA

  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.




                                                     1
Unit Operations ChE 382 Group 5                                                    Spring 2011 3/14/2011
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
Fluidized Bed                                             University of Illinois




                                  Lab Prep Report
                          Unit Operations II Lab 4
                                   March 14, 2011


                                          Group 5
                                    Andrew Duffy
                                   Daniyal Qamar
                                        Jeff Tyska
                                     Bernard Hsu
                                      Ryan Kosak
                                       Tomi Damo
                                    Alex Guerrero




                                                  2
Unit Operations ChE 382 Group 5                       Spring 2011 3/14/2011
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
Fluidized Bed                                                                                                                    University of Illinois




Contents
1.     Introduction .......................................................................................................................................... 4
2.     Literature Review/Theory ..................................................................................................................... 5
3.     Experimental ....................................................................................................................................... 13
     3.1.     Apparatus .................................................................................................................................... 13
     3.2.     Materials and Supplies ................................................................................................................ 16
     3.3.     Experimental Procedure ............................................................................................................. 18
4.     Anticipated Results ............................................................................................................................. 20
5.     References .......................................................................................................................................... 21
6.     Appendix I: Job Safety Analysis ........................................................................................................... 22




                                                                              3
Unit Operations ChE 382 Group 5                                                                                           Spring 2011 3/14/2011
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
Fluidized Bed                                                                            University of Illinois


1. Introduction

    The purpose of this lab is to measure the affects of superficial velocity and particle size on the

pressure drop in a fluidized bed reactor. A fluidized bed reactor consists of a column filled with a solid

packing. High velocity fluid flowing through the column unseats the solid packing causing the

subsequent fluid-particle mixture to then act as a fluid itself (Lab Packet 1). The fluid used can be either

gas or liquid. The most common purpose of a fluidized bed reactor is to ensure that there is ample

contact between the solid particles, reactor fluid, and the reactor walls. This allows for virtually uniform

temperature distribution even when highly exothermic reactions are occurring. Often times the solid

particles are used to catalyze the reaction occurring within the column. In many cases the solid packing

is a support for a catalyst, and fluidization of the particles allows for significant contact between

reactants catalytic particles. The most common uses for fluidized beds are catalytic cracking in the

petroleum industry, as well as coal combustion, catalyst regeneration, solid-gas reactors, ore roasting

and gas adsorption operations (Lab Packet 1).


    Though much more complex than a simple packed bed reactor, a fluidized bed reactor also includes

a void fraction for its packing. Because of the void fraction of the packing material, there is a maximum

velocity at which the fluid can move through the reactor without fluidizing the solid packing. The

particles are usually ≤ 500µm in length. However, in order for fluidization to occur, the fluid has to have

a minimum velocity in order for the particles to flow easily and rapidly. The observation of bubbles of

fluid passing through the solid packing of the bed is how one would determine that this minimum

velocity has been reached. The bed sits upon a distributor and this allows for an even fluid distribution.

Located at the gas outlet is a disengaging section which prevents solid particles from flowing out of the

system.


                                                      4
Unit Operations ChE 382 Group 5                                                     Spring 2011 3/14/2011
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
Fluidized Bed                                                                           University of Illinois


    Two different fluidized bed columns will be evaluated in this lab. The first will use sand as the solid

packing material. This sand will be of varying grain sizes and air will be the fluid. A second column will

be evaluated with silica as the solid packing material and air as the fluid. The second column will also be

heated. Flow rates and pressure drops throughout the column will be measured and recorded and then

the superficial velocity and minimum fluidization velocity of the system will be found using these

measurements. A relationship between gas velocity and pressure drop can then be established.




2. Literature Review/Theory


        Fluidized beds are commonly used in chemical engineering process for multiple purposes, such

as catalytic reactions, solid-gas reactions, coal combustion, roasting ores, drying, and adsorption

operations (McCabe 3). Even though fluidized beds also contain a packing material to give good contact

between the phases, they have several major differences from packed beds. First, the packing is

supported by the upflowing phases and behaves much like a liquid, hence the name. The packing phase

is in constant motion within the fluidized bed. Such a unit is more complex than a simple fixed bed and

has several advantages which can be important in industrial applications: (1) the rapid mixing motion in

the bed gives a high heat transfer rate between the bed and the shell of the unit; thus, heat can be

easily transferred to or away from the bed, (2) the bed unit tends to be quite uniform in concentration

when compared to the non-mixed packed bed; this can be an advantage or a disadvantage for a given

separation or chemical reaction, and (3) the packing can flow out of the unit for separate treatment and

back into the unit. (McCabe 145)




                                                     5
Unit Operations ChE 382 Group 5                                                    Spring 2011 3/14/2011
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
Fluidized Bed                                                                             University of Illinois


        At low gas velocities, the pressure drop through the bed can be described by the Ergun

equation. However, as the flowrate increases a point is reached where the pressure drop becomes

constant and does not change with gas flowrate. This is defined as the point of fluidization. The point of

fluidization is where the solid particles and the gas are in a state of equilibrium. When particles in the

bed become suspended on the upward following gas the system becomes known as a fluidized bed.

Fluidization can only be used with relatively small particles, <300 μm with gases (Sinnott, Towler 667). In

the case of this lab experiment sand and silica are used to test the affect of particle size on point of

fluidization and pressure drop. Visually, the bed does not appear like a fixed bed but there is random

motion of the particles within the bed; if a valve is opened on the side of the unit the packing will flow

out much like a liquid. Further increases in gas flowrate results in violent mixing within the bed and the

formation of large gas bubbles passing through the bed. Upon decreasing the gas flowrate, the pressure

drop versus gas flowrate does not exactly follow the previous curve as seen in figure 1 below. There is a

significant hysteresis effect due to the frictional forces in the initial packed bed. The reason for this path

dependence is due to a change in the orientation of the packing particles as they become looser than

before due to the air flowing through the bed; this results in a lower friction factor and lower pressure

drop.




                                                      6
Unit Operations ChE 382 Group 5                                                     Spring 2011 3/14/2011
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
Fluidized Bed                                                                          University of Illinois




        The behavior of the particles based on pressure drop with relation to upward superficial velocity

can be seen in figure 1 below.




                       Figure 1: Pressure Drop vs. Superficial Velocity (McCabe 3)


In this figure it can be seen as the pressure drop is increased the superficial velocity increases somewhat

exponentially until it reaches a plateau where the minimum fluidization point is. Along the first section

of the graph (area A) the pressure drop can be related to the velocity using the Ergun Equation

(equation 1 below). This equation can only be used in this section because of the small pressure drop

and velocity where it is considered a packed bed (Bird, Stewart, Lightfoot 191).




                                                     7
Unit Operations ChE 382 Group 5                                                    Spring 2011 3/14/2011
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
Fluidized Bed                                             University of Illinois




                                                                    (1)




Where:

P0 = initial pressure [Pa]

PL = pressure at the end of the column [Pa]

G0 = mass flux [kg/m2*s]

Dp = particle diameter [m]

L = height of the bed [m]

ε = void fraction [dimensionless]

ρ = density of the particle [kg/m3]

μ = viscosity [kg/s*m]




                                                  8
Unit Operations ChE 382 Group 5                       Spring 2011 3/14/2011
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
Fluidized Bed                                                                          University of Illinois


         However, as the velocity and pressure drop increase the Ergun Equation (1) cannot be used in

the determination of fluidized bed values. Figure 2 below also shows this relation but with the overall

bed height verses the superficial velocity in the column.




                        Figure 2: Bed Height vs. Superficial Velocity (McCabe 3)


Point C on both figures is the point of minimum fluidization velocity, Vf, and can be caluculated by the

following equations. (Note: The small frictional force exerted on the wall was ignored). First the

determination of the upward force by the gas on the bed can be calculated using equation 2 below.


                                                                                                 (2)

Where:

ΔP = pressure drop across the bed [Pa]

A = cross-sectional area of the bed [m2]




                                                     9
Unit Operations ChE 382 Group 5                                                   Spring 2011 3/14/2011
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
Fluidized Bed                                                                     University of Illinois


Next the volume of the particles can be solved for using equation 3 below.


                                                                                            (3)

Where:

ε = void fraction [dimensionless]

A = cross-sectional area of the bed [m2]

L = height of the bed [m]




From here we can determine the net weight of the particles in the column by using equation 4 below.


                                                                                                  (4)


Where:

A = cross-sectional area of the bed [m2]

L = height of the bed [m]

ε = void fraction [dimensionless]

   = density of the particle [kg/m3]

  = density of the fluid [kg/m3]

g = acceleration due to gravity [m/s2]




                                                  10
Unit Operations ChE 382 Group 5                                               Spring 2011 3/14/2011
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
Fluidized Bed                                                                         University of Illinois


The theoretical pressure drop can be determined by using equation 5 below.


                                                                                                  (5)

Where:

L = height of the bed [m]

ε = void fraction [dimensionless]

   = density of the particle [kg/m3]



Typically for a bed with small particles (Dp < 0.1 mm), the flow conditions are such that the Reynolds

number (Re) is relatively small (Re < 10) meaning that the Kozeny-Carmen Equation can be used to find

the velocity of fluidization (Vf) (McCabe 5). This Kozeny-Carmen Equation can be seen as equation 6

below.



                                                                                            (6)


Where:

Vf = fluid velocity [m/s]

ε = void fraction [dimensionless]

   = density of the particle [kg/m3]

   = density of the fluid (or gas) [kg/m3]

g = acceleration due to gravity [m/s2]

Dp = particle diameter [m]

μ = viscosity [kg/s*m]
                                                    11
Unit Operations ChE 382 Group 5                                                  Spring 2011 3/14/2011
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
Fluidized Bed                                                                             University of Illinois


         When the superficial velocity (Vs) is equal to the fluidized velocity (Vf) this state is known as

“incipient fluidization” (McCabe 5). Next the settling velocity can be determined by restricting the size of

the particle to be small like before so that Stokes Law can be used to calculate this velocity. This can be

seen in equation 7 below.



                                                                                                (7)


Where:

Vsettling = settling velocity [m/s]

   = density of the particle [kg/m3]

   = density of the fluid (or gas) [kg/m3]

g = acceleration due to gravity [m/s2]

Dp = particle diameter [m]

μ = viscosity [kg/s*m]

         Once the velocity of settling and the fluidization velocity are determined a ratio of the two can

be formed relating the void fraction back to both the velocities, which can be seen in equation 8 below.



                                                                                                 (8)



Where:

Vf = superficial velocity [m/s]

Vsettling = settling velocity [m/s]

ε = void fraction [dimensionless]


                                                      12
Unit Operations ChE 382 Group 5                                                      Spring 2011 3/14/2011
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
Fluidized Bed                                                                            University of Illinois


    In cases where the particles a very small it is likely that they may be carried out of the bed system.

Therefore, filters or cyclones must be emplaced to recover these particles at high superficial velocities.

Bubbling fluidization will occur in this experiment because this is strictly a gas-fluidized bed which will be

seen as large pockets of gas moving through the free particles.



3. Experimental


    3.1.Apparatus


Equipment                   Manufacturer                  Purpose                   Description

Rotameter                   Nupro Company                 To measure air            Max flow = 2.2 L / min.
                                                          flowrate on column on
                                                          left

Pressure meter              Omega Engineering             Measures pressure of      0 – 100 psi
                                                          air into rotameter
                                                          mentioned above

2 air valves                Crane Company                 Changes air flowrate      No. 1. Cranite Disk
                                                          into rotameter
                                                          mentioned above

2 Half turn valves          Smith Company                 Changes air flow rate     On bottom of each
                                                          into fludizied beds       fluidized bed

2 PVC columns               None listed                   Used as fluidized beds    Two are given

2 Tops                      None Listed                   Tops to fluidized beds    Funnels, so that sand is
                                                                                    easy to pour

3 Pipette bulbs            None Listed                    Used to keep sand       Normal pipette bulbs
                                                          from flowing out of the
                                                          fluidized beds

1 U-Tube Manometer         Meriam Instruments             Used to measure           0 – 25 psi
                                                          pressure drop in
                                                          fluidized beds

2- 250 mL Erlenmeyer       Pyrex                          Used to collect sand      Tubes hooked up to
                                                                                    fluidized beds and U-

                                                     13
Unit Operations ChE 382 Group 5                                                     Spring 2011 3/14/2011
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
Fluidized Bed                                                                         University of Illinois


flasks                                                 from the fluidized beds   Tube manometer

Plastic Tubes            None Listed                   Used to link up the       4 in total
                                                       fluidized beds and U-
                                                       Tube manometer to
                                                       the Erlenmeyer flasks

Set of Ceramic Spheres   None Listed                   Packing in the bottom     1 set in each column
                                                       of each column

Thermocouple             Fluke                         Used to show data         2166A digital
                                                       from thermometers in      thermometer
                                                       a fluidized bed

Thermometers             Omega                         Hooked up to              3 in total
                                                       thermocouple,
                                                       measure temperature
                                                       in a fluidized bed

Heater                   SE Engineering                Used to heat the          In the middle of the
                                                       fluidized bed             apparatus

Rotameter                F&P Co                        Used to measure the       13.9 CFM maximum
                                                       air flowrate in a
                                                       fluidized bed

Pressure Gauge           None Listed                   Measures pressure of      Made in China, 0 – 200
                                                       air to a fluidized bed    psi
                                                       (on the right)

Valve                    Apollo                        To main air supply        Yellow

Valve                    Willerson Corp                Used to change the air    Near the pressure
                                                       flowrate into the         gauge without a
                                                       rotameter on one of       manufacturer name
                                                       the fluidized beds




                                                  14
Unit Operations ChE 382 Group 5                                                  Spring 2011 3/14/2011
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
Fluidized Bed                                                       University of Illinois




                                                              Figure 3 Key:

                                                       1. Tops to fluidized beds
                                                       2. Fluidized bed columns
                                                       3. Ceramic spheres
                                                       4. Rotameter (Nupro)
                                                       5.   Pressure gauge (Omega Eng.)
                                                       6. Valve (Cranite)
                                                       7. Valve (Wilkerson)
                                                       8. Pressure gauge
                                                            (No manufacturer listed)
                                                       9. Rotameter (F&P Co)
                                                       10. Valve (Cranite)
                                                       11. Pipette bulbs
                                                       12. U-Tube manometer
                                                       13. Half turn valves (Smith)
                                                       14. Heater
                                                       15. Thermocouple




                Figure 3: Fluidized Bed Lab Station




                                                  15
Unit Operations ChE 382 Group 5                               Spring 2011 3/14/2011
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
Fluidized Bed                                                                         University of Illinois


      3.2.Materials and Supplies


Equipment               Manufacturer                    Purpose                  Description

1 Scooper               None listed                     Used to scoop out        Made of plastic
                                                        sand

1 yardstick             None listed                     Used to measure the      Also used for other labs
                                                        height of the sand

Air                     None                            Used to create the       From the main
                                                        fluidized bed            compressed air
                                                                                 line

Water                   None                            Used to help calculate   From a faucet
                                                        the density of sand

Wet-Dry Vac             Dayton                          For vacuuming up         120 V, 60 Hz
                                                        loose sand and silica

Sieves                  Us Standard Sieve Series        Used to separate the     Multiple sieves, 4750 –
                                                        sand into different      28 microns
                                                        size distributions

Graduated Cylinder      250 mL                          Used to store sand       TC/TD at 20 degrees
                                                        and water in for the     Celsius
                                                        density calculations

Beaker                  Pyrex                           Used to store sand in    40 mL
                                                        for the density
                                                        calculations

Funnel                  None listed                     Used to funnel sand      1 in total
                                                        into beaker and
                                                        graduated cylinder

Sea Sand                Fischer Scientific              For use as packing in    Normal sand, various
                                                        fluidized bed            particle sizes

Silica                  Fischer Scientific              For use as packing in    Looks like crushed
                                                        fluidized bed            quartz, similar particle
                                                                                 sizes




                                                   16
Unit Operations ChE 382 Group 5                                                  Spring 2011 3/14/2011
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
Fluidized Bed                                                                University of Illinois




                Figure 4: Solid Particle Sifters




                                                        Figure 5: Solid Particle (sand)


                                                   17
Unit Operations ChE 382 Group 5                                         Spring 2011 3/14/2011
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
Fluidized Bed                                                                        University of Illinois


   3.3.Experimental Procedure


Start Up

   1. Check that the apparatus and all required materials are present and in working order. Clean out

       columns (2) if not already clean.

   2. Clean, by taping, and stack the sieve trays in descending order of grain diameter. Set up a

       container to catch the fly off sand

   3. Record the diameter range of the two decided sand samples as well as the silica.

   4. Using a 100 ml graduated cylinder, add 25 ml of sand sample.

   5. Add an equal amount of water to the graduated cylinder.

   6. Allow sufficient time to pass for the water to penetrate the sand layer then measure the final

       volume.

   7. Use these measurements to calculate the void fraction. Repeater for each sample.



Sand Column Procedure

   8. Load the first sand sample into the left column (2). Add roughly 10 cm of sand to the column.

       Tap the column to even out the sand and accurately measure the sand’s height.

   9. Make sure all valves are in the proper starting position

   10. Fully open the valve at the base of the column (13), and then slowly open the flow meter valve

       (5) to allow air in.

   11. For each increment of change in the air flow record: the air flow rate, the pressure drop, height

       of the packed bed also any notable observations with the packed bed.

   12. Keep incrementally increasing the flow rate until the maximum is achieved. Maximum is noted

       by a plateau of pressure drop with increasing air flow.

                                                   18
Unit Operations ChE 382 Group 5                                                 Spring 2011 3/14/2011
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
Fluidized Bed                                                                         University of Illinois


   13. Repeat recording for decreases in airflow.

   14. Remove all the sand with the Shop-Vac and repeat steps 8 to 13 with the second sample of

       sand. Empty out the sand into separate container so not to mix it with the silica later on.




Silica Column Procedure


   15. Load silica in the right column (2). Add enough silica to cover the top thermal sensor by 1.5

       inches

   16. Open the air valve at the bottom of the right column (13) (have the left one closed) then slowly

       open the flow meter valve to let in air.

   17. For each incremental change in air flow record: the air flow rate, the pressure drop, the height

       of the packed bed and any observations.

   18. Once the maximum is reached record it.

   19. Start to slowly decrease the air flow rate and record the corresponding measurements.

   20. Turn of the air and the turn on the heater (14). Wait till packed material reaches steady state

       temperature.

   21. With the heated bed repeat steps 16 to 19. Along with the standard measurements also record

       both top and bottom temperatures.

Shut Down and Clean Up


   22. Turn of air supply (6), heater (14) and digital thermometer (15).

   23. Remove funnels (1) for the top of both columns and use Shop-Vac to clean the column and

       bench area.

   24. Organize sieve trays and place inside the cabinet.


                                                    19
Unit Operations ChE 382 Group 5                                                  Spring 2011 3/14/2011
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
Fluidized Bed                                                                      University of Illinois


4. Anticipated Results


       The purpose of this lab experiment is to use sand and silica to test the affect of particle

   size on point of fluidization and pressure drop. The point of fluidization is reached when the

   gas/liquid velocity is sufficient enough to lift the bed and cause it to behave like a fluid. As

   the air velocity going through the bed is increased the pressure drop is noted. This pressure

   varies according to the velocity of air flowing through the column and how tightly the bed is

   packed (the void fraction).

       The pressure vs. velocity graph should look very similar to figure 1. As the columns are

   packed and the air is let in, the pressure drop will start to increase. As more force will be

   required to loosen the bed and get the bed to start moving this pressure drop will keep rising.

   The bed height will appear to stay constant as the pressure drop rises. Eventually the pressure

   drop will stop increasing and the point of minimum fluidization velocity will be reached. At

   this point the bed has become fluidized and the sand or silica particles are loosened and

   flying around in the column. The bed height will appear to start increasing and at this point

   the energy needed to lift the bed particles is provided by the air velocity and increasing the

   height of the bed does not influence the pressure drop anymore. As the air velocity is

   increased it will reach a point when the sand or silica particles will start escaping the column,

   this velocity is called the settling velocity and beyond this point the particles will exit the

   column with the air. Just as in figure 1 as the velocity of air will be decreased the pressure

   drop will take a different path. The orientation of every particle will be a lot different than it

   was before the minimum fluidization velocity was reached; the bed was a lot tightly packed



                                                  20
Unit Operations ChE 382 Group 5                                               Spring 2011 3/14/2011
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
Fluidized Bed                                                                      University of Illinois


   and not loosened yet. Since all the particles rearrange to a loosened configuration the

   pressure drop as the velocity is decreased will be less as well.

       In addition to the air velocity affect on the pressure drop, the particle grain size will also

   affect the pressure drop. The size of the particles determines the void fraction which affects

   the superficial velocity and the pressure drop as well. The finer the grain size is the lower the

   void fraction is since the bed will be tightly packed. Referring to equation 6 it is clearly

   evident that as the particle size increases (increase in void fraction, the diameter, and the

   density) the superficial velocity increases as well. This increase in velocity will give rise to a

   higher pressure drop as well. Since the diameter, the density, and the void fraction are all

   going to be bigger for larger particles it can be concluded that a bigger value of the minimum

   fluidization velocity will be seen for the bigger particles. However the finer grains will result

   in a larger bed height since finer grains are easier to raise as the same pressure drop is

   applied.

       The silica bed will be heated so an effect of temperature will be seen here as well. As the

   air will expand upon heating the pressure drop will appear to increase as well. From

   equations 5 and 6 it can be seen that as the density of the fluid decreases (expanded air, same

   mass bigger volume) the velocity and the pressure drop both increase. The bed height will

   appear to be bigger as well since the air occupies more volume when heated.




5. References

Bird, R. Byron, Warren E. Stewart, and Edwin N. Lightfoot. Transport Phenomena. New York: J. Wiley,
2007. Print.

                                                  21
Unit Operations ChE 382 Group 5                                               Spring 2011 3/14/2011
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
Fluidized Bed                                                                       University of Illinois


"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.




6. Appendix I: Job Safety Analysis

       What is the purpose of this experiment?

The purpose of this experiment is to determine the gas pressure drop across a bed of particles as

a function of the gas velocity. The fluidization behavior of a bed of small particles will be

studied.



       What are the hazards associated with the experiment?

The spilling of sand and silica on the floor, which will occur during operation of the column and

during the sifting of the sand in order to obtain the right particle size range, makes for a slippery

work environment. Compressed air is used to fluidize the bed. Since there is air passing through

small sand and silica particles, it is possible that these particles could enter the eye, nose and/or

mouth. A heater adjacent to the fluidized bed apparatus is used and could possibly expel

exuberant amounts of heat and burn the operator.




       How will the experiment be conducted in a safe manner?

A vacuum is included with the station to maintain a clean working and walking area when sand

                                                  22
Unit Operations ChE 382 Group 5                                                Spring 2011 3/14/2011
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
Fluidized Bed                                                                     University of Illinois


and silica are being used. Eye protection will be worn so that sand and silica particles do not

enter the operator’s eyes. Care should be taken not to inhale either of these particles and hands

will be washed after working with the silica.




        What safety controls are in place?

The air inlet regulator has an internal diaphragm that will maintain constant inlet pressure of 40

psig. Should the pressure increase erratically, the regulator valve will relieve the pressure to

maintain the inlet pressure. The vacuum cleaner has a filter adapter attached which prevents

excessive dust accumulation when cleaning up the area. The columns are fitted with a

disengaging section to prevent solid particles from leaving the system.



        Describe safe and unsafe ranges of operations.

In order to prevent blowing sand or silica out the top of the column, operate at a superficial

velocity below the settling velocity. Carefully controlling increments air flowing through the

column will prevent the discharge of the bed out the top of the column. Silica column cannot be

heated to temperatures greater than 110°F. Should the Plexiglas reach temperatures of 265ºF,

then it will melt.



        I have read relevant background material for the Unit Operations Laboratory entitled:

“Fluidized Beds” and understand the hazards associated with conducting this experiment. I have

planned out my experimental work in accordance to standards and acceptable safety practices

and will conduct all of my experimental work in a careful and safe manner. I will also be aware
                                                  23
Unit Operations ChE 382 Group 5                                              Spring 2011 3/14/2011
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
Fluidized Bed                                                                 University of Illinois


of my surroundings, my group members, and other lab students, and will look out for their safety

as well.




       I have read relevant background material for the Unit Operations Laboratory entitled:

“Fluidized Bed” and understand the hazards associated with conducting this experiment. I have

planned out my experimental work in accordance to standards and acceptable safety practices

and will conduct all of my experimental work in a careful and safe manner. I will also be aware

of my surroundings, my group members, and other lab students, and will look out for their safety

as well.




                                                  24
Unit Operations ChE 382 Group 5                                          Spring 2011 3/14/2011
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska
Fluidized Bed                                              University of Illinois




Electronic Signatures:

                                        Bernard Hsu

                                       Daniyal Qamar

                                          Jeff Tyska

                                       Alex Guerrero

                                         Tomi Damo

                                         Ryan Kosak

                                       Andrew Duffy




                                                  25
Unit Operations ChE 382 Group 5                        Spring 2011 3/14/2011
Damo, Duffy, Guerrero, Hsu, Kosak, Qamar, Tyska

				
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