Sizing a Compressor

http://cr4.globalspec.com/thread/35303/How-to-Select-a-Compressor

If the load is periodic, ie; air tools in a garage, a piston and tank compressor is fine. For steady-state loads, ie; blowers, air loaders, pnuematic assembly tools, a rotary compressor is more efficient. Where demand is constant, but the load on the system varies, a variable speed rotary is best. See the aforementioned article for determining your CFM and pressure requirements.

Compressors you say find many solutions at the web site of the makers here is the one for FS Curtis

http://www.fscurtis.com/home/

when you are ready to buy go to liftandlube.com here is the link, http://www.liftandlube.com/Air_Compressors_s/4.htm

We have all your compressor needs, mounting pads ect. We will also be stocking Ingersol Rand soon in our home garage department, http://www.liftandlube.com/THE_HOME_GARAGE_s/135.htm

This section of the web site is not complete yet so give me a call if you need any items not there,

we also have hose reels like this Graco 250 series hose reel, also comes in an enclosed model

http://www.liftandlube.com/Reels_s/36.htm

Mention cr4 and i will give you a free filter regulator with any purchase, KB

I am new in this engineer's place and I am working in a company that produses compressors.

So, what you really need is to know is the compressed air consumption of the tools or machines you use and if the use of them is constant or periodic. the next thing is the pressure of the compressed air that this tools-machines require.

all of them you can find them on their data sheets.

In the data sheets also you will find the quality of the air that you might need ( water , particles....) so you can choosedryer, filters or.....

the next important think you have to do is to desigh carefully and size twice carefully you air main.

If you need more help just let me know.

Why don't you try our site www.kaeser.com there you will also find a very usefull toolbox that will help you to calculate your needs

Dear all,

Compressor that I need is used for vapor recovery in LPG transfer.
When unloading LPG from the ship, pump is used to transfer LPG. And the compressor is used for help the pump to available enough NPSHa in ship end.

After the liquid level in the ship reach their LLV (Lowest Liquid Level), transfer from the ship is not using pump anymore. The transfer LPG liquid then using compressor.

The pump line is closed, then compressor suck vapor in the ship vessel to reduce pressure until all LPG vaporised and then transfered to the LPG tank.

Look at the scheme :

Fig 1. Transfer with pump

Fig 2. Transfer with Compressor (When LLV is reached)

The questions are :

1. If pump transfer flow rate is 1000 m3/h, is compressor flow rate must be same with the pump flow rate to keep pressure in the ship end?

2. How to estimate power consumption for the compressor?

3. What kind of compressor shall we used? This is intermittent application.

4. What standards used for this compressor application?

The pressure in ship vessel is kept 10 bar, and the pressure in the tank is kept 9-10 bar.

Thanks for all your attention.

Give me two days more and i will have your answer.Its not that easy cause of the specific conditions of LPG...my email is gkapetas@hotmail.com just in case i will need to send you some big file of drawing maybe i will need yours too

You should give me some data.The temperature of the storaged LPG ,the size of the ship and the earth tank . and also the desired time of unloading

Airend,
This is my email : tomo_tm02@yahoo.co.id

Temperature outlet from ship is 15 deg C, temperature in the storage tank is 20 deg C. Pipe length from ship to storage tank 600 meter, pipe liquid diameter 12 in, pipe vapor diameter 6 in.
Storage tank capacity 2500 MT (4839 m3, SG of LPG is 0.517), size of the ship 25000 DWT.
Pumping capacity from the ship is 1000 m3/h.

Thanks for your help..