blend refrigerant

[moideen]

hi,my friends

what is the blend refrigerant?i want to know the defference between the blend refrigerant and ordinary refrigerant.can anybody help?

[dr gy]

zeotropic blends like 134a or 404a for example are several gases mixed to give the desired refrigeration, but as they are a blend they boil off at different temps so any leak to atmospere in which 30% of charge is lost refrigerant must be reclaimed and sent for recycle/ destruction etc hope this helps

[Brian_UK]

The difference is that a pure refrigerant is simply that, a single pure refrigerant.

A blend is made up of more than one refrigerant.

Check with the manufacturers of the gases that you are interested in and they will tell you the composition of the blend.

[PaulZ]

Hi moideen
There are 3 types of blended refrigerants, Non Azeotropic mixtures which have a high temperature glide (generally above 3K), Near Azeotropic mixtures which have a low temperature glide (generally below 3K) and Azeotropic mixtures which have a 0 temperature glide.
The higer the temperature glide figure the more they will fractionate or change their composition if a leak occurs especially if it is a gas leak.
R134a is a single refrigerant, Tetrafluroeathane not a blend as stated by dr gy, it has a glide of 0 and therefore would not need to be removed after a leak. R404A is a 3 mix blend, Tetrafluroethane 4%, Pentafluroethane 44% and Trifluroethane 52%. It's glide is only 0.5K and you would have to have successive leaks to warrant removing all the refrigerant and starting again.
Non Azeotropic refrigerants would need to be recovered after leaks, some of these are R401A, R407C, R409B and R409A.
Ordinary refrigerants as you put it would be most of the refrigerants that have been or are being phased out. Most new refrigerants are blends but not all need to be replaced after a leak.
A good rule of thumb when charging blended refrigerants is to do so as a liquid.
Google properties of refrigerants and I ma sure you will find a comparison chart.
Hope this helps.
Paul