If an air-entrainment system mixes air with O2 at a fixed ratio of 1:7, what approximate O2 concentration does this provide?

In an air-entrainment system that mixes air with oxygen at a fixed ratio of 1:7, it is essential to understand the implications of this ratio for the overall oxygen concentration. The ratio indicates that for every 1 part of air, there are 7 parts of oxygen being delivered.

To determine the overall oxygen concentration, first, you must recognize that normal atmospheric air consists of approximately 21% oxygen, with the remaining 79% being primarily nitrogen and other gases. When mixing air (21% O2) with oxygen (100% O2) in the given ratio, we can calculate the resulting concentration.

In this case, the mixture consists of one part air (21% O2) and seven parts pure O2 (100% O2):

• The contribution from the air: 1 part air x 21% O2 = 21% O2

• The contribution from the oxygen: 7 parts O2 x 100% O2 = 700% O2 (since all parts are pure oxygen)

Next, we add these contributions:

21% + 700% = 721%

The total number of parts in the mixture is 1 (air) + 7 (O2)