China has more than a dozen large companies which etching glass with hydrofluoric acid, hundreds of photovoltaic industry, metal surface treatment more than a dozen large companies, the waste generated each year is about 15,000 tons of organic residue fluorine, hydrofluoric acid content is about 4.5% on average , causing damage to the environment, a lot of waste of resources.

100% hydrofluoric acid at room temperature to the boiling point is 19.54 degrees, the boiling point of a total is 38.4%. If keep enough cold water to diluted hydrogen fluoride at 19.54 degrees, can be arbitrarily high concentration of hydrofluoric acid, hydrofluoric acid aqueous solution of 2.5% volume fraction because it is only a partial pressure of 30 Pa on the solution at 50 degrees (in this case water vapor partial pressure is 12,000 kPa) with the help of a low concentration of hydrofluoric acid HF is absorbed better than fresh water, when this absorption liquid circulation with 20% volume fraction, we can adopt high-quality HF, this time at a certain temperature, 20 % volume fraction HF solution as absorbent (partial pressure of 440 Pa) when the vapor-liquid equilibrium vapor HF concentration of 71.6 milliliters per cubic meter.

Organics completely decomposed after the incinerator, hydrogen fluoride is introduced into the absorption solution in the lower furnace into a dilute acid, the unfinished portion of the absorbed vapor is absorbed into the absorber again, with a circulating water cycle acid absorption column temperature dropped to a certain temperature, acid-edge absorption edge diverted, under the furnace with an acid into the receiving groove, while another part of the back frame tower continue absorption cycle, the receiver tank installed bypass valve, able to live out the amount of acid analysis and control to gravity into the sump.