"Scroll" or "Screw"

[Robearbam]

Is there a difference between the two? I hear "scroll" when referred to refrigeration and "screw" for air compressors...are they the same?

[NoNickName]

NO, scroll are spirals rotating one into the other.

http://www2.mat.dtu.dk/info/experiencing/scroll/graphics/scrollindtag.jpg

Screws are two counter-rotating shaft.

http://www.compressor-spares-manufacturer.com/gifs/screw-air-end-servicing.jpg

[US Iceman]

Is there a difference between the two?....are they the same?

No. They are completely different types of compressors. The avatar in my response shows a twin screw compressor.

A screw compressor consists of rotors that mesh together. As the rotors turn they create compression (low pressure/large volume to high pressure/low volume).

The scroll compressor works in the same manner, except the compressor consists of two plates that rotate together.

The links below show some basic details of twin screw compressors:
http://www.greenbusinesscentre.com/Documents/Scroll%20Compressors.pdf

http://www.copeland-corp.com/cp_rf/prod_sol/cp_rf_products_scroll.htm

Here is some information on screw compressors:
http://www.copeland-corp.com/cp_rf/prod_sol/cp_rf_products_screw.htm

http://translate.google.com/translate?sourceid=navclient-menuext&hl=en&u=http%3A%2F%2Fwww%2Ebitzer%2Ede%2Fdocument%2Findex%2Ephp

http://www.carlylecompressor.com/corp/details/0,2938,CLI1_DIV24_ETI10562,00.html

Some larger screw compressors. These are a variety called a single screw.
http://www.vilter.com/pdf/VSS_final.pdf

There also some three rotor screws deing developed, but I can't seem to find any links right now.

[star882]

Scrolls tend to be small or medium size while screws are generally large.

[Lc_shi]

it's similar type but both one become covered each other.