8 replies to this topic

[Mohamed cage]

hello all,

in order to optimize the air compressor system used in our cement plant , and as a first step i am calculating the air requirement of all equipment that use compressed air ( bag filters , air cannon (air blaster ) , cleaning system, etc ..) 

by doing some research I've found some formulas that are suitable and give good estimations, but i don't know if they are really valuable ( from a project for Holcim in morocco ) :

- for air cannon and bag filters :

Q= N*L*P*X ;  in  [m3/h]

where : Q : is the flow rate required [m3/h] ; N:  the number of installed receivers ; L : the volume of the air cannon receiver [m3];  X : the number of pulse per hour  .

note that this calculation is to have a first estimation on the required compressed air only ( from the manufacturer's data ) ,

 

your advises and opinions are valuable for me .

thank you .

Edited by Mohamed cage, 14 April 2019 - 12:14 PM.

[Chemitofreak]

Hi,

 

Better talk to the respective vendors for the package. It is always better. Same package with different vendors can have different utility consumption.

 

Regards,

[breizh]

hi ,

Agree with the answer above , don't forget the spare volume or spare compressor /air storage  you need in case of emergency to actuate valves ,operate equipment .. . Only you or people from your plant can answer .

note : on top of that , the shelf life of the de-duster system and bags are very much linked to the air quality . Moisture is very much detrimental .

 

https://airpollution...g/sonairtm.html

 

Above link is about a company I used to work with for lime kiln extraction  .  I don't remember using compressed air , each system  having its own blower !

 

Good luck

Breizh

Edited by breizh, 15 April 2019 - 07:14 PM.

[Mohamed cage]

thank's for your answers , 

for bag filters I've found an excel sheet that simplify the calculation  , and for the other system i will use the pump up test method , i found it in an Indian book : 

" The compressor to be tested and a known volume of receiver have to be isolated separately from the main line. Totally empty the compressed air receiver and close the outlet valve of the receiver. Also it should be ensured that there is no condensate water inside the receiver and the drain valve is also fully closed. Start the compressor and note down the time taken for raise in pressure in the receiver to the normal operating pressure (P2) from the initial pressure (P1). The same exercise can be repeated for about three times.

The free air delivered by the compressed air can be calculated using the following formula.

 

Average Compressor delivery = ((P2 – P1) x VR) / P x Δt       m3 / min.

 

with :

P1 : initial pressure in receiver (kg/cm2)

P2 : final pressure in receiver (kg/cm2)

P : atmospheric pressure (1.033 kg/cm2)

VR : Volume of air receiver (m3)

Δt : time taken for charging the receiver from P1 to P2 (min)

 

While estimating the volume of compressed air storage the volume of after cooler, volume of pipeline from the after cooler to the receiver should be included along with receiver volume.

Also, since the compressed air temperature at discharge is higher than the ambient temperature, the free air delivered has to be multiplied by the following correction factor :

 

Correction factor = Tatm + 273 / T1 + 273

 

Where

T1 - Temperature of compressor at discharge

Tatm - Ambient temperature in 0 °C

Attached Files

•  filtre calcul.xls   69.5KB   42 downloads

[breizh]

hi ,

A few resources about air compressor , compressed air, distribution network .

Hope this is helping you.

Good luck

Breizh

[Mohamed cage]

thank you for this valuable documents .

[Miraj]

Could you @Breizh please reshare the the resources about compressor, compressed air and distribution networks? They do not show in your post, at for now 

[breizh]

Hi Miraj,

Attached the documents requested.

Breizh

Attached Files

•  storage capacity compressed air.pdf   204.93KB   13 downloads
•  Compressed air water content.pdf   280.02KB   14 downloads
•  Compressed air distribution.pdf   279.56KB   13 downloads
•  Calculating Storage for Demand Events.pdf   4.14MB   15 downloads
•  Compressed_Air_Manual_Atlas Copco.pdf   5.91MB   12 downloads

[shvet1]

Compressed Air & Gas Handbook

https://www.cagi.org/resource-library