ok friend lets solve this problem lets start with your packing materials ok?

differences in diameter

ok lets first dinf out the differences in diameter:

let the diameter of packing 1 be greater than packing 2

D1>D2 which means that radius 1 is greater than radius 2, r1>r2

for simplicity sake lets take for example that there is a chemical reaction happening in your packed bed so we can use the diffusitivity equation which is:

J=A.D.(c1-c2)/d (mol/sec)

where:

A is the area of the packing

D is the diffusitivity constant

c1 is the concentration at the bottom stage of the bed

c2 the upper stage of the bed

d is the distance between the two packings

here we can see that at large area we can say that there is a larger diffusion than the one with a lesser area,

recall that area is A:3.14156.r.r.2

which means smaller diameter beads are favorable because they can obtian more chemical reaction due to the larger of the surface are is exposed(area of the packing is different from the surface area of the packing)

so lets go to packings with different masses:

recall that the force required by the pump to run is equals to the summation of the:

1.)resistance of the surface of the pipe used to allow the fluid to flow

2.)the resistance of the fluid to flow,viscosity

3.)the mass of the packings used,recall that force=massxgravitational pullx the difference in height...

so the 3rd factor is quite critical because:

if the packing is lighter then the bed will easily fluidized and the force that the pump exert is lesser thus we have a lesser power consumption meaning,less electrical bill

now if the packing is heavier then the bed will not easilty fluidized, the pump will exert more force and there is an increase in the power consumption....