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Offline Bashir2008

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How to design a water media filter
« on: April 25, 2008, 09:42:00 AM »
Hello every body
I really need your help in fact that I am not an engineer. so please if anyone of you has knowledge about my concern so please help me to solve my questions.
 I will start doing a work about Floating media filter and will use a polymer beads as a media for my filter
 
At the moment I am busy doing some caracterization analysis of some particles which will be tested on the filter next step.

  will give u some more information concerning my work.
 
What I want to do is test some different polymer beads and see if have an effect or not of removing some contamminates.. I am intersted to remove the turbidity and suspended solids and the colour from the water.. I will  work with a specific feed water ( not sewage or biological concern )..
 
in my future work ( in 6 months time ) I might do experiment ( test the beads ) on a big fliter which will be somewhere on Water treatment plant..
 
But at the moment to test a small amount of beads ( such as 2 or 3 kg ) I need to design a small filter... 

1- could you  give me a diagram with the main things that i need it beside the body filter itself.. such as pump..may be flowmeter, and how to measure the velocity ahow to add a coagulation. and how we connect all of these tools with filter ?
2- If i need to measure the void of my beads.. so how can i do a simple experiment ?
3- is it important to take the pressure drop into account while the filter is working and how to measure the pressure head ( head loss)
4- when when we talk about the packed bed surface area... so what dose it mean exactly ? is it just the area the beads will be settle in ?
 
5- there is an onoter term might be very important which is Floccolation... so could u explain about it and what is the importance of it ?
 
Finally I really need your help
 
Best regards

Offline eugenedakin

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Re: How to design a water media filter
« Reply #1 on: April 25, 2008, 07:54:55 PM »
Hello Bashir2008,

I have designed many systems that you are asking, but this is a helpful forum.  What I will ask is that you provide me with the work that you have performed.  I can help you with the work that you are doing, but, according to the forum rules, I cannot do the work for you.

Perform some common searches and I am sure that you will be able to start to answer some of the questions you have posted.

Thanks,

Eugene
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Offline Gerard

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Re: How to design a water media filter
« Reply #2 on: April 27, 2008, 03:40:36 AM »
1- could you  give me a diagram with the main things that i need it beside the body filter itself.. such as pump..may be flowmeter, and how to measure the velocity ahow to add a coagulation. and how we connect all of these tools with filter ?

-i suggest you read two books:
one is called transport phenomenon by bird
the other one is still called transport phenomenon by beek and mutzall
the third is transport process and operations by geankoplis
you'll understand your questions better :)

2- If i need to measure the void of my beads.. so how can i do a simple experiment ?

-easy first you take the samples of the packings (beads)
second,fill a graduated cylinder with the packings
third,using another graduated cylinder filled with water,pour the water into the cylinder with the packings up to the last calibration unit...
third,subtract the volume of water used by the total volume of water,the difference of the two is the void volume that is occupied by your sample...(this is an experiment done to determine the packings in a fixed bed reactor)
3- is it important to take the pressure drop into account while the filter is working and how to measure the pressure head ( head loss)

-what we usually do is we attach a calibrated pipe fill it with mercury then calibrate it to atmosperic pressure(1 atm) in our case then we run the equipment then we take note of the changes in the pressure head of the mercury i terms of mmhg....

4- when when we talk about the packed bed surface area... so what dose it mean exactly ? is it just the area the beads will be settle in ?

-packed bed surface area?i think that is the area when your packed bed is empty,beacuse if you were refferring to the paking area it is given by its producers, like the raschig rings and the intalox saddle we used...
 
5- there is an onoter term might be very important which is Floccolation... so could u explain about it and what is the importance of it ?
-this is self explanatory,read environmental engineering by thobanoclous
"Charles! Charles! That's it Mr. Charles Darwin get out of this room, I told you once and I told you twice not to tease your fellow Mr. Arrhenius!"

Offline Bashir2008

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Re: How to design a water media filter
« Reply #3 on: April 28, 2008, 05:58:54 AM »
Artificial student...thaks a lot for replying and will geb back to u soon.

Offline Bashir2008

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Re: How to design a water media filter
« Reply #4 on: April 28, 2008, 06:11:37 AM »
Dear: Eugene

Firstly:thank u very much for replying
Secondly: I am not saying that you do the work for me. but what i meant is in fact the I am not an engineer design so i suppose that will take too long time to understand and do such a design. and Its not such a task for me to do.. the real work that i have to do is to test some materials on this filter but because do not have a small filter scale to test our materials so we are trying to make one and here in my department we do not have assistance department that can help us.
I hope u understand my point.

Thirdly:

What i have done is too little is..I have different matrials ( polymer beads ) i will use them as a media for floating media filter..they are different shapes  and say i have 500mg to 2kg ..

1- so i need to put this amount ( it could be 500mg and could be 2kg in this range ) into the filter
2- i need the water flows ( upflow )
3- the beads diameter around 2 - 5 mm.

I really need your help ...do u have any other question shall i answer ?

what i need is just a diagram or so and then i can start doing my real experiments...

by the way:i need to test the feed water turbidity and then flow rater and flow velocity and pressure drop and product water turibitity and colour reduction.. these factors are what all my work about but to do it i have to built up a filter which is not my field..So please try to help me.

Best regards

Offline Gerard

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Re: How to design a water media filter
« Reply #5 on: April 29, 2008, 10:02:43 AM »
Dear: Eugene

Firstly:thank u very much for replying
Secondly: I am not saying that you do the work for me. but what i meant is in fact the I am not an engineer design so i suppose that will take too long time to understand and do such a design. and Its not such a task for me to do.. the real work that i have to do is to test some materials on this filter but because do not have a small filter scale to test our materials so we are trying to make one and here in my department we do not have assistance department that can help us.
I hope u understand my point.

Thirdly:

What i have done is too little is..I have different matrials ( polymer beads ) i will use them as a media for floating media filter..they are different shapes  and say i have 500mg to 2kg ..

1- so i need to put this amount ( it could be 500mg and could be 2kg in this range ) into the filter
2- i need the water flows ( upflow )
3- the beads diameter around 2 - 5 mm.

I really need your help ...do u have any other question shall i answer ?

what i need is just a diagram or so and then i can start doing my real experiments...

by the way:i need to test the feed water turbidity and then flow rater and flow velocity and pressure drop and product water turibitity and colour reduction.. these factors are what all my work about but to do it i have to built up a filter which is not my field..So please try to help me.

Best regards


first of all i please understan professor eugene, his a professional chemist so i bet he is very busy,
secondly he is not a teacher so he is right that it is our job to research on what our topic is like what i do i do not single handedly rely on sir eugene's advise i also run down thruogh my books, paticularly my research topic "biogas" which i am not an expert...
thirdly, it is most to your advantage if you know what you want wiht your fixed bed reactor,,,
i have read that it is an upflow, i suggest you read about fixed-film UASB's hybrids or upflow fixed bed reactors and try to learn the concepts, remember you can invest in many things if you read...right?
"Charles! Charles! That's it Mr. Charles Darwin get out of this room, I told you once and I told you twice not to tease your fellow Mr. Arrhenius!"

Offline eugenedakin

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Re: How to design a water media filter
« Reply #6 on: April 30, 2008, 07:18:40 PM »
Hello,

Yes, thank you for your patience.  I help answer the questions in my spare time, and when the question has been partially determined, it allows me to help out many people.

An answer to one is your questions is a photograph of a UASB. Here is the link to a picture of a Upflow Anaerobic Sludge Blanket:

http://www.fao.org/docrep/t0541e/T0541E02.GIF

I do not understand your question (statement?).  Could you rephrase your question?

Thank you for understanding.

Sincerely,

Eugene
There are 10 kinds of people in this world: Those who understand binary, and those that do not.

Offline Gerard

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Re: How to design a water media filter
« Reply #7 on: April 30, 2008, 09:39:58 PM »
What i have done is too little is..I have different matrials ( polymer beads ) i will use them as a media for floating media filter..they are different shapes  and say i have 500mg to 2kg ..

-i suggest you dont used a random packing whose data is not yet established you might have problems using it, experiment on the two packings and determine which one gives more effeciancy with less power consumption

1- so i need to put this amount ( it could be 500mg and could be 2kg in this range ) into the filter

-it depends on the capacity of your reactor, both its capacity to hold the packings and the capacity to let the fluid flow upward....,so you might try to experiment with it
2- i need the water flows ( upflow )
-upflow.....dont forget to use a pump to force the fluid up
3- the beads diameter around 2 - 5 mm.
-calculate the surface area by the area of a circle/sphere
"Charles! Charles! That's it Mr. Charles Darwin get out of this room, I told you once and I told you twice not to tease your fellow Mr. Arrhenius!"

Offline Bashir2008

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Re: How to design a water media filter
« Reply #8 on: May 05, 2008, 03:32:18 PM »
Hello Prof Eugen.

Thanks for your reply..
What i am asking for is to help me.how to make a design for a laboratory scale water filter ( upflow ).
In fact that i am not an engineer. I am an analytical..so i need to run some experiments on the filter but could not get any help so far..
I really do not know how to do it..the main task of my work is to study the effect of some parameters such as ( turbidity, velocity, pressure..)
I believe that:there will be some calculation i should start with to make the design..
1- Could you put me on the way ?
I have a certain amount of materials will be used as a media for floating media filter.
its about 500g to 1kg..and its about 3 mm diameter.
So how to make a laboratory scale filter.

I appreciate your reply

Best regards

Offline Bashir2008

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Re: How to design a water media filter
« Reply #9 on: May 05, 2008, 03:54:52 PM »

Hello artificial student
Thank u once more

-i suggest you dont used a random packing whose data is not yet established you might have problems using it, experiment on the two packings and determine which one gives more effeciancy with less power consumption
I will use my materilas ( i am not gona use any other people data )

1- so i need to put this amount ( it could be 500mg and could be 2kg in this range ) into the filter

-it depends on the capacity of your reactor, both its capacity to hold the packings and the capacity to let the fluid flow upward....,so you might try to experiment with it
Ok could you tell me what size or volume should my filter must be ?


2- i need the water flows ( upflow )
-upflow.....dont forget to use a pump to force the fluid up

3- the beads diameter around 2 - 5 mm.
-calculate the surface area by the area of a circle/sphere

Ok. do u mean the surface area of the beads ? then what can i do when i get the area ? and must i calculate the total paked area ? could u give me some details here ?

4- What are the basice of deisgn a fliter ? i really want to know must i have to start design ? as i told u its just a laboratory scale filter 

Best regards

Offline Gerard

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Re: How to design a water media filter
« Reply #10 on: May 11, 2008, 01:47:15 AM »
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....
"Charles! Charles! That's it Mr. Charles Darwin get out of this room, I told you once and I told you twice not to tease your fellow Mr. Arrhenius!"

Offline Gerard

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Re: How to design a water media filter
« Reply #11 on: May 11, 2008, 01:55:38 AM »
3- the beads diameter around 2 - 5 mm.
-calculate the surface area by the area of a circle/sphere

Ok. do u mean the surface area of the beads ? then what can i do when i get the area ? and must i calculate the total paked area ? could u give me some details here ?

to find the total packed area multiply the area...
i think you will multiply the area with the total volume occupied by the packing then divide this by the void volume you obtain,,,,,
that is:
(cm2xcm3)/cm3

4- What are the basice of deisgn a fliter ? i really want to know must i have to start design ? as i told u its just a laboratory scale filter

this is a very complicated question friend, i suggest you look into books like chemical engineering unit operations...
if you'll ask me i set up in my back yard a water treatment column but its quite simple here is goes:
i design a vertical cylinder and covered one side with PVC at the bottom of the cylinder i bore a hole attached a pipe and a pump, this is where the water goes in, (feed) then i fill the cylinder with the following:
first layer is charcoal
second layer limestone
3rd layer is coarse sand then i attached a pipe at the top and i connect it to a small tank for chlorination.....that's what i did

"Charles! Charles! That's it Mr. Charles Darwin get out of this room, I told you once and I told you twice not to tease your fellow Mr. Arrhenius!"

Offline Bashir2008

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Re: How to design a water media filter
« Reply #12 on: May 12, 2008, 03:33:25 PM »


 Hello friend ( artificial student )
lots of informations..

I have some more questions if you do not mind..
1- I suppose that there are a critical diameter of a filter that will be used in water.. what is that diameter ?
in other words..I want to make a filter with 1.5 m lenght, so what is the best size of diameter that should i make ? because i think will be some wallside effects at a certain lenght and diameter,,am i right ?

2- Say for instance i have 25 kg of materials will be used as packing materials ( media ) for a filter and say my filter diameter will be 300 mm and the lenght of the column is 1 - 1.5 m .
My question is what is the typical bed of these materials in this filter ? in other words.. what will be the depth of the bed if i put the whole 25kg of beads into the filter.

Note: ( bead or particle diameter range 2-4 mm ).

3- What are the main factors or parameters that effect the filter packed bed ?

Finally :thank you very much and looking forward to hear from you
Best regards
 
 

Offline Gerard

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Re: How to design a water media filter
« Reply #13 on: May 15, 2008, 01:37:16 PM »


 Hello friend ( artificial student )
lots of informations..

I have some more questions if you do not mind..
1- I suppose that there are a critical diameter of a filter that will be used in water.. what is that diameter ?
in other words..I want to make a filter with 1.5 m lenght, so what is the best size of diameter that should i make ? because i think will be some wallside effects at a certain lenght and diameter,,am i right ?

-i need to read Unit OPerations books for this,there was a derived equation that was offered in the Chemical engineering unit operations by McCabe....sorry i have to review on this,all i remember  was that the wal side effect is called channeling and air cavities....i hope you should also do your reading too

2- Say for instance i have 25 kg of materials will be used as packing materials ( media ) for a filter and say my filter diameter will be 300 mm and the lenght of the column is 1 - 1.5 m .
My question is what is the typical bed of these materials in this filter ? in other words.. what will be the depth of the bed if i put the whole 25kg of beads into the filter.

Note: ( bead or particle diameter range 2-4 mm ).

-as a rule of thumb,you should operate at a 40-55% of the capacity, you should give an allowance in case ther will be operational disturbances like water up surge or water overloading,in this manner your packed bed will not overflow or will not flood...
try experimenting...locate the maximum capacity of the bed,if you have located this operate at the stated percentage
you can experiment either by:
having a constant packing depth with varying flowrates or by having a constant flow rate with varying packing depth...
the maximum capacity is the shortest time that the packed bed will fluidized, when the packing starts to vibrate...the critical capacoty can be noticed when the packing starts to float vigorously due to water turbulence...

3- What are the main factors or parameters that effect the filter packed bed ?
-water flow
-packing materials
-pump capacity
-materials of constructions
usually it depends on how you use your pack bed...for wastewater treatment,for drinking water treatment,of treating wastewater with high organic content etc....

Finally :thank you very much and looking forward to hear from you
Best regards
 
 

"Charles! Charles! That's it Mr. Charles Darwin get out of this room, I told you once and I told you twice not to tease your fellow Mr. Arrhenius!"

Offline Gerard

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Re: How to design a water media filter
« Reply #14 on: May 18, 2008, 06:10:09 AM »
friend i suggest you read a book entitled:
UNIT OPERATIONS OF CHEMICAL ENGINEERING
by Warren L. McCabe,Julian C. Smith, Peter Harriot
McGraw-Hill isbn:0-07-118173-3
"Charles! Charles! That's it Mr. Charles Darwin get out of this room, I told you once and I told you twice not to tease your fellow Mr. Arrhenius!"

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