What is the difference between dense and dilute phase in PCS?

Posted in: , on 12. Feb. 2004 - 08:47

Dear Ms or Mr:

Please make me clear!!!

What is the difference between dense and dilute phase in PCS?

I already have heard that dense phase is more efficient than dilute phase in energy consumption.

Our plant have 6 PCS systems which are all dilute phase and transfered material is polypropylene.(BD: 0.47, Particle size: 1000 ~ 2000¥m)

Is it possible to transfer PP(polypropylene) by dense phase?

What is the criterion of transfering method which system is adopted in PCS system?

Many thanks

Y.W.Lee

Assistant Manager

Polymer Production Technology

Samsung Atofina Company

Tel : +82-41-660-6745 Fax : +82-41-660-6789

Mailto:yw4279.lee@samsung.com

http://www.SamsungChem.Com

PANDIAN, Mumbai, India
(not verified)

The Bulk Density Of Polypropylene In Ton/M3 And Particle Size O…

Posted on 12. Feb. 2004 - 05:30

Dear Sir ,

Can you please indicate the bulk density of polypropylene in ton/m3 and particle size of polypropylene in mm

Regards

SUBASHPILLAI

Regards

SUBASHPILLAI

AXIOM

CONSULTING AND MARKETING ENGINEERS

NO 11 , TARVOTI BHAVAN

Ist Floor , 203 P.D'Mello Road

Fort

Mumbai-38

Tel +91-22-22672600

Fax +91-22-22658927

E-mail :subashpillai@hotmail.com

nrskullu@yahoo.co.in

Bulk Density And Particle Size In Pp

Posted on 13. Feb. 2004 - 12:09

Dear Sir:

I'd like to say like this.

1.Bulk Density : 0.47 ton per cubic meter polypropylene

2.Particle size : 1~2 mm.

Many thanks.

Best regards.

Re: What Is The Difference Between Dense And Dilute Phase In Pc…

Posted on 18. Feb. 2004 - 04:36

Dear Mr. Lee,

The real difference between dense and dilute phase PCS's is that dense phase is LOW VELOCITY and dilute phase is HIGH VELOCITY. For PP (pellets, or granules, or fluff), either of these are acceptable but the choice between them will depend upon your economics. i.e., both on capital investment and operating cost. You can go to well known vendors and have them send you quotations for both options. You could then run an economic comparison yourself.

Regards,

A. T. Agarwal

Pneumatic Conveying Consultants

www.powderandbulk.com/pcc

polypcc@aol.com

PANDIAN, Mumbai, India
(not verified)

Re: Bulk Density And Particle Size In Pp

Posted on 21. Feb. 2004 - 09:20

Originally posted by ehfanrp

Dear Sir:

I'd like to say like this.

1.Bulk Density : 0.47 ton per cubic meter polypropylene

2.Particle size : 1~2 mm.

Many thanks.

Best regards.

====================================

Dear Sir ,

The difference between dense phase conveying and dilute phase conveying is that in case of dense phase conveying SOLID TO AIR RATIO is high ( above 12 ) (i.e) 1 kg of air or conveying medium is used to convey more amount of solids . Normally the three phases are represented as follows .

1 ) Dilute Phase = solid to air ratio upto 6

2 ) Medium Phase =solid to air ratio from 7 to 13

3) Dense Phase = solid to air ratio beyond 14

Since less amount of air or any other gas media is used for conveying more amount of solid , the compressor motor rating will be less in case of dense phase conveying resulting in less specific power consumptions (i.e) kwh/ton of material conveyed .

In dense phase conveying , due to less amount of air is used , the conveying velocity is less compare to lean phase conveying , but no case velocity of conveying media should not be less than terminal settling velocity of bigger size particle in the material

The flow of material in dense phase conveying is not continuous , it is plug flow , the material move in pockets .

All the material is not suitable for dense phase conveying . Some material which is normally conveyed by lean phase , medium phase pneumatic conveying system , can not be conveyed by dense phase penumatic conveying . It is purley depend upto the fluidisation behavior of the material

In case of dense phase conveying pressure drop is more , hence you require pressure vessel associated with gas tight valves etc for pumping material .

Hence the investement cost is more in case of dense phase pneumatic conveying , but operating cost is less due to less power cosnumptions and less wear of pipe lines bends etc . In this regard I have directly sent to your e-mail ID , one word doccument "DENSE-DILUTE" , which shows the investement and life cycle cost difference between DENSE PHASE AND LEAN PHASE PENUMATIC CONVEYING SYSTEM . This article is Published by M/s MACAWBER BEEKAY ENGINEERING in the INTERNET . In the same file I have mentioned the site address also. You can directly view this site in internet .

The power consumpitions of dense phase pneumatic conveying system for any material is like inverted " U " . The compressor motor rating will decrease as we go on increase the SOLID TO AIR RATIO , but beyond certain point the motor rating of compressor will start increase as we increase the solid to air ratio , because the increase in the pressure drop across the conveying line . So SOLID TO AIR RATIO should be at this optimum value only .

Normally before selecting any kind of high solid to air ratio for particular material in the view of designing DENSE PHASE PNEUMATIC CONVEYING SYSTEM , those materials should be tested in pilot plant for it's fluidisation behaviour for such high solid to air ratio or there should be proven record / earlier referrence for such kind of densphase system for that material .

In case of polypropylene , both dilute phase and dense phase is suitable . However , I will check , upto what solid to air ratio the dense phase conveying system can be designed .

If you any more clarifications to be replied , please feel free to ask .

SUBASHPILLAI

AXIOM

CONSULTING AND MARKETING ENGINEERS

NO 11 , TARVOTI BHAVAN

Ist Floor , 203 P.D'Mello Road

Fort

Mumbai-38

Tel +91-22-22672600

Fax +91-22-22658927

E-mail :nrskullu@yahoo.co.in

subashpillai@hotmail.com