2 replies to this topic

[Bashir]

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

[Andree]

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?

measurement of flowrate gives you enough information to calculate superficial velocity through filter element... this is the most important parameter that needs to be established experimentally and which is required for sizing (how much filtration area is required)
I do not know what you mean saying "add a coagulation" - please clarify... and connection with filter? filter has to be in a housing/enclosure, connections depend on specific design...


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

generaly methods involve flowrate and pressure drop measurement... you can also estimate this (very roughly) when you know density and bulk density of you media... if you mean measurement of pores, some people measure it using optical microscopy


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)

of course it is very important process parameter! you need to know what pressure drop is for clean element, and pressure drop indicates element replace or regeneration...
you can measure this using differential pressure sensor... or simplest/cheapest and very "academic way" to do it is using U-tube filled with water, and connected: one end before filter, second end after filter, and measure level difference


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 ?

in the case of packed beds it usually refers to specific surface area in m2/m3 or m2/kg of packing...


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 ?

the observed effect of flocculation process is similar to coagulation, i.e. agglomerating of smaller particles into clusters... however flocculation is brought about by addition of ionic substance having opposite charge to that on particles... coagulation usually refers to destabilization of colloids by addition of coagulant - substance (e.g. electrolyte) that cause decrease of electrical double layer which is formed around particle in ionic solution... repulsive forces between particles decreases and aggregation (coagulation) can take place due to: Brownian diffusion, van der Waals attraction or convection (depending on system hydrodynamics)...

[Bashir]

Hello Andree

first of all thank you for the information

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