HW 8 - SP1 - Filtration of a Beer Containing Protease - 4 pts
A suspension of Bacillus subtilis has been fermented to produce the enzyme protease. In order to separate the biomass, we added 1.3 times the biomass of a Celatom filter aid, yielding a beer containing 3.6 wt% solids with a viscosity of 6.6 cP. With a Buchner funnel 5 cm in diameter attached to an aspirator, we have found that we can filter 100 mL of this beer in 24 minutes with a pressure drop of 14.7 psi. However, previous studies with this type of beer have had a compressible cake with s = 2/3.
We now need to filter 3000 L of this beer in a plate-and-frame filter press. The press has 15 frames, each with an area of 3520 cm2 on each side. The resistance of the filter medium is much smaller than the resistance of the filter cake.
a.) How long will take to filter the beer at 50 psig ?
b.) How long will it take at 25 psig ?
We now need to filter 3000 L of this beer in a plate-and-frame filter press. The press has 15 frames, each with an area of 3520 cm2 on each side. The resistance of the filter medium is much smaller than the resistance of the filter cake.
a.) How long will take to filter the beer at 50 psig ?
b.) How long will it take at 25 psig ?
posted by Dr. B at 8:27 AM
5 Comments:
The Buchner funnel provides a pressure drop across the filter cake of 14.7 psi.
How do you find the mass of the biomass? You stated that it was 1.3 times the biomass of the Celatom filter aid and we are confused as to what this means.
johnny cage:
You don't really need to use this fact in your solution. They just added a lot of filter aids because this biomass (probably cells) is extremely compressible. I conclude this because s = 2/3 is relatively large and this is the value WITH filter aids !
I can't seem to get the right answer. I'm confused on Across of the plant and and/or volume. We don't need to use weight % solids somehow, right? I've tried a lot of different ways but can't seem to get the right answer.
Anon:
The Across for the plant is 2*15*3520 cm^2 because there are 15 frames and 2 sheets of filter medi per frame.
Vlab = 100 mL, Vplant = 3000 L
No, you do not use the xF = 3.6 wt%
I suggest you draw yourself a picture and think about what is happening and what each number means. Once you really understand this process, I think you will find this problem to be straightforward. But if you have any other questions, feel free to blog or come to office hours (mine or Joseph's) on Monday. I will check the blog again Sun night.
Post a Comment
<< Home