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Powder Conveying System

02/25/2010 1:01 PM

Dear all,

In our new system powder will get transfer through air in pipe,

But my doubt is where this air will get collected in such a system.

Anybody knows about such a system.

Please guide me.

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#1

Re: Powder conveying system through air

02/25/2010 1:30 PM

If I understand your description correctly, the powder should be delivered to a container with a filter that allows the air to vent out.

I have seen this system used with grain where the grain drops out of the air tube into a silo and the air escapes from the top of the silo. If your powder is lightweight and tends takes time to settle into the container, you will need to separate the powder using filters that will allow the air to escape and the powder to settle in the tank.

Drew

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#2

Re: Powder conveying system through air

02/25/2010 1:38 PM

There are systems that "blow" material (often times powder) from one location to another. The pressure they operate at and the percent of solids to air vary per application and manufacturer. Some are called dense phase or dilute phase etc.

In all the such systems of this type I have had experience with, the air is separated from the powder at the destination end by something often called a "bin vent". This is similar to a dust collector in that they use filter media to separate the air from the material. The bin vent often sits on top of the bin where the material just falls into the bin and the air escapes thru the filter media and out the exhaust.

The bin vent usually does not need a fan like a dust collector since it already has air being passed to it.

Like Drew K said the material is directed down into the bin so little or almost none of the material actually has to be stopped by the media, depending on material density and particle size.

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#3
In reply to #2

Re: Powder conveying system through air

02/25/2010 1:48 PM

Hi there, DaveB.

Your description sounds a lot like the cyclone we use to collect sawdust:

http://en.wikipedia.org/wiki/Cyclonic_separation

Not sure if this is what OP is looking for, but might help.

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#4
In reply to #3

Re: Powder conveying system through air

02/25/2010 2:02 PM

Doorman I believe a cyclone could work under the right circumstances.

The difference between a cyclone and a bin vent/dust collector is a cyclone separates the solids with centrifugal force where as a bin vent/dust collector uses filter media to "filter' the two out.

When the particle size and density of the material is consistently large enough to permit centrifugal separation and the air velocity is high enough for the induced swirl, the cyclone is better because it is a simpler device. The bin vent option is probably more common because of the constraints needed for a cyclone to work well.

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#5
In reply to #4

Re: Powder conveying system through air

02/25/2010 2:34 PM

Hello again, DaveB.

I may have been making assumptions for information not given. Sandeep has many posts regarding the manufacture or packaging of spices. On previous posts, he indicates there is (or at least was) an issue with the natural oils of many products clogging various filter media already used in the packing plant. It is my assumption this thread deals with another aspect of his venture, and I used (perhaps incorrectly) this information to form my opinion, but neglected to share my interpretation with the group.

I do believe your suggested method would probably give more satisfactory results, if the issue of oils in the product is not at issue. This due to the less violent accumulation process of filtration.

Aside from that, I am not certain we are answering the correct part of his question. We must wait for Sandeep to check in, and let us know.

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#7
In reply to #5

Re: Powder conveying system through air

02/25/2010 4:23 PM

Thanks for the heads up that there may be something that clogs filter media.

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#6

Re: Powder conveying system through air

02/25/2010 3:59 PM

If you do a google search for pneumatic conveying systems that may yield you some good information.

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#8

Re: Powder Conveying System

02/26/2010 12:04 AM

"But my doubt is where this air will get collected in such a system"

The pneumatic conveying system is fairly common in many powdered product manufacturing plants. The air used to convey the powder is exhausted to the atmosphere by means of a cylone or air separator. In some cases the exhausted air is passed thru a dust collector to remove the light density powder (dust) that goes out with the air.

The basic equipment of a pneumatic powder conveying system consist of an air blower, normally positive type blowers with high air volume delivery; powder feeding rotary valves or some air lock system to feed the powder to the pipes;then the long pipes that leads to the silos or storage bins. For multiple silo storage, a common cyclone separator is used, the collected powder is feed to each silo by a drop pipe or any suitable conveying system to transport the product to storage or packaging bins.

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#9
In reply to #8

Re: Powder Conveying System

02/26/2010 3:11 AM

If your powder is an organic (like sugar), you had better consider the possibility of a dust explosion (assuming you are using air to transport). Talk with Fike or other knowledgable people to find out.

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#10
In reply to #8

Re: Powder Conveying System

02/26/2010 1:20 PM

Thank you everybody,

I think rupertal got my point.

I have both the system cyclon as well as dust collector with reverse pulse air jet.

The way you people mentioned may be oil partical stuck in filters pores but reverse air jet work better to unlock it.

Please let me know how this cyclone work with centrifugal principle as well as bin vent.

My powder is chilly powder which is creating problem in environment.

Please let me know about scrubber.

will it work ?

Thanks

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#11
In reply to #10

Re: Powder Conveying System

02/27/2010 2:27 AM

Hello Sandeep!

There are several cyclone designs and they have to be adapted to the kind of product that you handle. But the basic principle applies as aptly described by one manufacturer.

Dust-laden air is blown into or drawn through the cyclone and forced to move in a circular motion. The airstream spirals downward to the base of the unit as centrifugal forces move the heavier dust particles to the side walls. The motion continues spiraling downward to the base of the unit. The dust then falls out and the air reverses up through the inner tube and out the top.

Separation efficiency is determined by the cyclone geometrical parameters, the density of the solids and the rotational velocity of the air stream. It is essential that the geometry of each internal component be designed to promote a smooth transition in maintaining laminar flow characteristics.

Chili powder is a difficult product to handle. I have worked on it some years ago, quite nasty to the eyes and the nose. If you intend to use a scrubber, the chili dust cannot be recovered since a scrubber will remove the dust by means of a high pressure water spray in an enclosed chamber. The efficiency of your cyclone to separate the chili powder dust may not be very good and a high percentage is blown into the air.This will certainly cause an environmental issue in your plant.

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#12
In reply to #11

Re: Powder Conveying System

03/01/2010 2:35 AM

Hi

scrubber will help us or not?

which type of water spray will help us?

Thank you.

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#13
In reply to #12

Re: Powder Conveying System

03/01/2010 7:33 AM

Hello!

I believe a wet scrubber will work in removing most of the fine dust that cannot be separated by the cyclones or collected by the bag filters. A spray nozzle that generates a very fine mist can collect as much chili dust. However, you will also need to treat the water or pass this through a filter to remove the chili powder.

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#14
In reply to #13

Re: Powder Conveying System

03/01/2010 7:46 AM

Good day, have you considered vibratory pipe feeders. I have seen some in action transferring very fine crusher dust which was probably heavier than chilli powder would be. The system had remarkably low 'dust' emissions. regards, Leon.

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#15
In reply to #13

Re: Powder Conveying System

03/01/2010 12:17 PM

Dear all

Please let me know which kind of spray nozzle is suitable for this application?

Thank you.

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Users who posted comments:

Anonymous Poster (1); DaveB (3); ddk (1); Doorman (2); Drew K (1); Leonf (1); rupertal (3); sandeep lokhande (3)

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