Acid Etch processes can be completed with a variety of chemicals. Acid Etching with HCL often results in a very aggressive evolution of Hydrochloric Gas, and HCL Fog. Due to the aggressive nature of HCL it requires the maximum exhaust/ventilation rate in accordance to the Industrial Ventilation Manual set forth by the ACGIH. The ACGIH classifies the hazard potential for HCL fume control at the highest hazard potential and consequently the highest exhaust volumes are used for correctly designed exhaust ventilation system.
It also requires a specially designed Fume Scrubber System to control high concentrations of HCL. The Scrubber required to control HCL contains a significant packing depth, up to 10 feet, a higher than standard irrigation rate. It must also be understood that when HCL comes in contact with water an exothermic reaction takes place changing the gas to an aerosol, (HCL Fog). The Wet Pack Scrubber can remove the HCL gas up to 99% and still the HCL fog will likely occur. This requires the HCL scrubber design to be equipped with a special secondary mist eliminator that is comprised of a very high efficient Mesh Pad HCL Fog Mist Eliminator. Only with the high efficiency scrubber design and the addition of the secondary mesh pad can the HCL fog eliminator can be expected to have zero visible emissions from HCL process including: etching, pickling or any other process using HCL and base metal.
Other strong acids are used for etching of stainless steel, titanium, or other high alloy metals. These would include Nitric Acid, a Nitric and Hydrofluoric Acid Bath, and multiple acid baths. Some of these baths that KCH has designed exhaust/ventilation and scrubber systems for contain Nitric Acid, Hydrochloric Acid, Hydrofluoric Acid, Phosphoric Acid, and Ferric Chloride, all in one multi-acid etching bath. Please contact KCH for design specifics on strong etch baths, as well as pickling, and passivation systems.
KCH also provides Acid Etch process tanks and complete lines.