8 replies to this topic

[seth]

Dear Experts,

I need some technical information regarding Air receiver tank design to be used in our new blasting facility. i have to design an Air Receiver tank that can supply the six blasting pot. the following data are available;

A.) Proposed no. of blasting pot to be used = 06
Capacity per pot = 137 CFM, 7 Bar
Operating hours = 18 hours

B.) Compressor details
Capacity = 700 CFM
Operating pressure = 10 bar
Ambient temperature = 50 Degree centigrade
Efficiency = 75%
quantity = 03 units

Please help me to design the air receiver tank size at given parameters

Your assistance is highly Appreciated.

[ankur2061]

Seth,

You joined the forum on March 26, 2009. It means that you should be now familiar to navigate through the forum. Have you used the search option for looking up your query?

I can assure you there are at least a half dozen postings on air receivers as well as a spreadsheet posted by me for air receiver sizing.

Kindly take the pains of searching and you will get all your relevant answers.

Regards,
Ankur.

[JoeWong]

Ankur is right... Search for it...you will gain more than you expected...
You may be interested in this post

[breizh]

Hello ,
aditionnal informations available on www.engineeringtoolbox.com under Compressed air receivers.
Regards
Breizh

[seth]

Readers,

Thank you very much for all the reply. anyway,I have attached an schematic diagram wherein the purpose of my previuos querry is to design a blasting system facility. please advise if this sketch with corresponding parameters will work.


Thanks in Advance,

Seth,

Design Engineer

Attached Files

•  Sandblasting_system_design.xls   28.5KB   138 downloads

If the pots will not operating same time,
137cfm/(10-7)bar = 45.67 cubic feet

[seth]

Sheshan,

have you scrutinized my attachment? what is the relation of your calculation on my proposed sandblasting air system sketch.. please review it.


thanks,

Seth

[Pressure Vessel]

I've heard so many rules of thumb over the years, it was interesting
to find this excerpt from the Carbon Trust suggests the following..

The size of an air receiver will depend on the amount of fluctuation
in air demand. In most cases an adequately sized receiver will be able
to supply the extra air during a high demand period and then recharge
when the demand drops off. This function allows the air compressor to
be sized for the average demand, rather than for the maximum demand.
In some cases when the fluctuation is too great, a solution can be to
have a smaller compressor that can ‘kick in’ as required.

There are a number of formulae for calculating the storage volume
required. However, the following empirical rule can provide an
approximation for planning purposes, taking into account the compressor
(s) output and the pattern of demand.

The Air receiver should be sized (in Litres) to be at least 6 – 10
times the compressor free air output (in litres/s)

It is also worth considering the following:
• To provide optimum performance, the receiver should be sized for the
largest expected air demand event.
• An undersized receiver will cause the compressor to cycle frequently
in response to small changes in pressure.
• An oversized receiver will cost more and will store more air, but it
will require the compressor to remain on load for longer periods to
recharge the air receiver. This is balanced by the extra time the
compressor will have to cool before it must come on load again.
• The volume of the pipe work is often significant but is not included
in the calculations.
• An effective control system will ensure that the receiver volume
balances the demand from the system with the supply from the
compressor.

For more info on Air Receivers - and where to get them ex stock and
built to real UK standards....visit
and sizing.......
http://www.air-recei...r_receivers.htm
and
http://www.air-recei...ure_vessels.htm


I hope this is of some help

[Art Montemayor]

Pressure Vessel:

There is something either wrong or mis-typed in your reported relationship as you stated it:

“The Air receiver should be sized (in Litres) to be at least 6 – 10 times the compressor free air output (in litres/s)”

One cannot equate two different units. In other words, litres cannot equal litres/sec. Do you mean to say that an air receiver should be sized by taking the compressor’s Free Air Delivery capacity figure and multiplying it by a factor 6 to 10 – regardless of what the volumetric units are as long as the volumetric rate is per seconds and the volumetric units used are also applied to the receiver’s volume capacity? Here, the Free Air Delivery capacity is defined as “the actual quantity of compressed air measured at the discharge of the compressor?

You infer that the air compressor you describe does not have an efficient aftercooler and discharge water separator. Does this mean that the Free Air Delivery Volumetric rate is measure at the discharge pressure and discharge temperature? I don’t think so.

Correct me if I am wrong.
I think the conditions at which the air capacity ia measured should be clearly and accurately defined.