Previous in Forum: Rotor Losses   Next in Forum: Adverse Effects of Running DC Motor at Lower than Rated Voltages?
Close
Close
Close
7 comments
Participant

Join Date: Jul 2011
Posts: 3

Capacity of Lobe Compressor Required to Convey Solid

07/29/2011 6:37 AM

Hi,

I want to calculate the required capacity of lobe compressor to convey 2292 kg/hr green beans(coffee).

Specific density of beans=0.7,

Height to which it is conveyed = 19m

horizontal distance = 10m

Please let me know how to calculate the required capacity.

Register to Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Guru
United Kingdom - Member - Indeterminate Engineering Fields - Control Engineering - New Member

Join Date: Jan 2007
Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing, in the nation formerly known as Great Britain. Kettle's on.
Posts: 30461
Good Answers: 819
#1

Re: capacity of lobe compressor required to convey solid

07/29/2011 6:41 AM

It would be quicker to contact pneumatic conveying specialists directly rather than rely on CR4 readers. An internet search engine will find any number of potential equipment suppliers, who will quote their capacities in their budget quotations.

__________________
"Did you get my e-mail?" - "The biggest problem in communication is the illusion that it has taken place" - George Bernard Shaw, 1856
Register to Reply
Guru

Join Date: Dec 2010
Location: 1° North Singapore
Posts: 568
Good Answers: 16
#2

Re: Capacity of Lobe Compressor Required to Convey Solid

07/29/2011 10:53 AM

2292 *9.8 *19= 426770 J/hr= 118 watt

1 hp would be a good starting point.

__________________
Sharing knowledge is one thing that defies basic arithmetic logic --- the more you share, the more you get!
Register to Reply Score 1 for Good Answer
Guru

Join Date: Oct 2008
Posts: 42294
Good Answers: 1663
#3
In reply to #2

Re: Capacity of Lobe Compressor Required to Convey Solid

07/29/2011 11:10 AM

For the second time this morning I get to say, "you should engage brain before typing."

The OP should take the advice of PWSlack. You should sit on your hands for awhile.

Register to Reply Score 1 for Off Topic
Participant

Join Date: Jul 2011
Posts: 3
#4

Re: Capacity of Lobe Compressor Required to Convey Solid

07/29/2011 2:23 PM

I want to know how much air flow rate should be provided by the compressor in m3/hr.

Register to Reply
Guru

Join Date: Oct 2008
Posts: 42294
Good Answers: 1663
#5
In reply to #4

Re: Capacity of Lobe Compressor Required to Convey Solid

07/29/2011 4:14 PM

I agree. Especially if the OP really wants to pump the beans 62.3 feet into the air.

Register to Reply
2
Guru

Join Date: Dec 2010
Location: 1° North Singapore
Posts: 568
Good Answers: 16
#6
In reply to #4

Re: Capacity of Lobe Compressor Required to Convey Solid

07/29/2011 9:13 PM

For a small company in developing country, money and availability of technical expertise is always a constraint. The OP requirement is 2292kg/hr, so it is no where near those big silo system.

I think it is not a very difficult engineering problem , only require a bit of practical engineering approximation and experimentation, this is how you should go about doing it:

The force to move an object up an inclined path F=mg sin (angle of inclination),

The force due to air speed on a ball shape object F=1/2 * 1.22*V^2 *Cd*A; where Cd is coeff of drag (0.47 for ball shape); A is cross section area of bean.

From this equation, you get air speed v.

From bean flowrate Qb=2292 kg/hr=2292/700/3600=0.91 liter/sec, and given air speed v, you can find area occupied by bean flow, Ab; Ab=Qb/v.

Assume the bean flow will will occupy 30% of pipe area Ap, so you can find area of pipe, Ap= Ab/0.3.

So , the blower air flow rate Q=v*Ap

Watch out, above equation are in metric units.

Start with these approx values and adjust the RPM of the blower, flow rate is proportional to rpm. Motor power , from my earlier post 1 hp , perhaps to be on safe side, use 3 hp to give more room for adjustment.

The steps are , start with the blower with the required air flow rate, adjust rpm.

__________________
Sharing knowledge is one thing that defies basic arithmetic logic --- the more you share, the more you get!
Register to Reply Good Answer (Score 2)
Participant

Join Date: Jul 2011
Posts: 3
#7
In reply to #6

Re: Capacity of Lobe Compressor Required to Convey Solid

07/30/2011 12:45 AM

thanks a lot.

Register to Reply
Register to Reply 7 comments
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Copy to Clipboard

Users who posted comments:

bravo88 (2); lyn (2); PWSlack (1); shubhi misra (2)

Previous in Forum: Rotor Losses   Next in Forum: Adverse Effects of Running DC Motor at Lower than Rated Voltages?

Advertisement