Acid Gas Scrubber

Acid gas scrubber is a wet purification device for waste gas containing acid components. The selection of this equipment starts from the acid components in the waste gas and the alkali neutralization reaction, not from tower structure. Acid gas is neutralized by alkali spray, converting gaseous pollutants into soluble salts that are discharged with the liquid. The scrubber uses alkali (typically sodium hydroxide solution) as the absorption medium. The tower body is made of PP or fiberglass, with packing layer, spray layer, and mist eliminator inside.

• Step 1: confirm the acid components in the waste gas. Sodium hydroxide solution neutralizes acid gas such as hydrogen chloride and sulfur oxides rapidly. Purification efficiency depends on gas-liquid contact.
• Step 2: select alkali concentration. Circulating water tank can be fitted with pH automatic dosing system to replenish alkali according to circulating liquid pH, maintaining absorption liquid concentration.
• Step 3: select packing layer quantity. Packing layer provides gas-liquid contact area; empty tower gas velocity controlled at 2.4–2.7 m/s to ensure sufficient contact. Multi-layer packing suits higher acid gas concentration.
• Step 4: select tower material. PP tower body is corrosion-resistant to alkali and acid gas, operating stably from -10 to 120°C. PP Pall ring void ratio 89%–93%, large gas flow channel, low pressure drop.
• Mist eliminator at tower top captures entrained droplets, reducing alkali loss and duct corrosion.
• If waste gas temperature exceeds 120°C, fiberglass or stainless steel tower body can be selected, or a pre-cooling section can be added before the scrubber.

• Acid components to confirm before selection: hydrogen chloride (HCl), sulfur oxides (SOx), or mixed acid gas. Different acid components affect alkali consumption and packing layer quantity.
• Alkali consumption: calculated from acid gas concentration and air volume. pH automatic dosing system maintains circulating liquid pH and reduces manual adjustment.
• Gas-liquid contact time: empty tower gas velocity 2.4–2.7 m/s. If acid gas concentration is high, multi-layer packing or higher liquid-gas ratio can be selected.
• Temperature limit: PP tower body applicable up to 120°C. For higher temperature, fiberglass or stainless steel tower body, or a pre-cooling section before the scrubber.
• Duct and fan matching: pressure loss 390–780 Pa. Fan pressure should cover tower pressure loss plus duct resistance.
• Discharge liquid: neutralized salts are discharged with circulating liquid. Blowdown frequency depends on acid gas concentration and operating time.

• Absorption medium concentration adjusted to acid gas concentration and type
• Packing type and layer quantity configured to acid gas concentration
• pH automatic dosing system optional
• Tower material: PP or fiberglass, selected to waste gas temperature
• Circulating water pump power and piping configured to site conditions
• Pre-cooling section optional for waste gas above 120°C
• OEM/ODM: customized to acid gas composition, concentration, and air volume; customer brand on nameplate and outer packaging

After tower welding, weld seam sealing is checked, confirming no leakage. Before packing installation, packing specification and filling density are checked. Spray system is tested circuit by circuit for spray uniformity. Circulating water pump test run records current and flow. 100% powered test run before packing, confirming spray and circulation system action. Third-party inspection accepted. The factory has supplied this equipment to electroplating, chemical, and metallurgy workshops, and uses this field data to set packing layer quantity and liquid-gas ratio.