The Model 9 earned its name because the fuel burning rate at maximum output is 9 oz weight per hour.
The Model 9 stove was capable of burning 9oz weight of fuel per hour which allowed the melting of snow in three minutes at high altitude creating one quart of water.
The Model 9 stove was capable of burning 9oz weight of fuel per hour delivering 20 quarts of water every hour.
Larry Penberthy calculated a stove would need a fuel burning rate of 9 ozweight per hour to boil a quart of water in three minutes for melting snow in the cold at high altitude to prevent dehydration. Hence the name Model 9.