sub-boiling acid steam ultra cleaning purification distillation
Why Sub-boiling?
Sub-boiling distillation has been demonstrated to be the best method of acid purification and acid cleaning. It uses heaters to vaporize the liquid at a temperature typically 5-20 °C below the boiling point.
With conventional distillation, the boiling of acid generates aerosolized particles, resulting in contamination of the distillate. In contrast to this, gentle surface evaporation during sub-boiling distillation prevents the formation of spray or droplets, yielding high-purity acids.
What is the benefit?
In order to get the desired high purity, the acid temperature must be strictly controlled below the boiling point to make the acid gently vaporize under sub-boiling condition.
Achieving peak performance in an acid purifier or acid steam cleaner hinges on the precise detection and control of the actual acid temperature.
Nitric Acid (HNO3)
Nitric acid is a strong acid and a powerful oxidizing agent. Concentrated nitric acid on distillation at atmospheric pressure starts boiling at 78.2℃ but decomposes eventually to give 68% nitric acid with a boiling point of 120.5℃(249°F) at 1 atm.
Nitric acid and water form an azeotrope, which is a constant-boiling mixture. The azeotrope is made up of about 68% nitric acid and 32% water by mass.
Hydrochloric Acid (HCl)
The boiling point of hydrochloric acid depends on its concentration. A 20% solution of hydrochloric acid has a boiling point of about 110 °C (230 °F), while a 38% solution has a boiling point of about 149 °C (300 °F). These boiling points are higher than those of pure water because of the presence of the HCl molecule and its interactions with water molecules.
Hydrofluoric Acid (HF)
Hydrofluoric acid evaporates at around 20°C, which can quickly lead to a dangerous concentration in the air.
Hydrofluoric acid is a weak acid with a pKa of 3.19. It's colorless with a strong and irritating odor. It's miscible in water and forms a clear and colorless aqueous solution.
Hydrofluoric acid forms an azeotrope with water, consisting of 37% HF by weight, with a boiling point of 120 °C.
sub-boiling acid steam ultra cleaning purification distillation