A PP spray tower(absorption tower)is a vertical,counter‑current wet scrubber made of polypropylene(PP),designed for high‑efficiency removal of corrosive gaseous pollutants and fine particulate matter from industrial exhaust.It is also known as a PP absorption tower,PP scrubber tower,or acid‑base purification tower,widely used in chemical,electroplating,pharmaceutical,and waste gas treatment applications.

1.Construction&Materials

Tower Body:Made of PP(polypropylene)plates,with excellent resistance to acids,alkalis,and most organic solvents;suitable for pH 1–14 and continuous operation below 60°C.

Spray System:Multi‑layer PP nozzles(large‑flow,anti‑clogging)atomize absorption liquid into fine droplets.

Packing Layer(Optional):Filled with PP Pall rings or Raschig rings to increase gas‑liquid contact area.

Mist Eliminator:PP vane‑type or mesh‑type demister at the top to remove entrained liquid droplets.

Recirculation Sump:Integrated PP tank at the bottom for liquid collection,circulation,and chemical dosing.

Gas Inlet/Outlet:Flanged connections for ducting,with optional tangential inlet for uniform gas distribution.

2.Working Principle

Gas Entry:Contaminated gas enters the tower tangentially from the bottom and flows upward.

Counter‑Current Spray:Absorption liquid(water or chemical solution like NaOH)is sprayed downward via multi‑layer nozzles,forming a dense mist.

Pollutant Removal:

Acid/Alkali Gas Absorption:Gases such as HCl,SO₂,H₂S,and NH₃dissolve or react with the liquid(e.g.,acid‑base neutralization).

Particulate Capture:Dust/fume particles collide with droplets,adhere,and settle.

Mist Separation:Cleaned gas passes through the mist eliminator to remove liquid droplets.

Liquid Recirculation:Contaminated liquid flows to the sump,is recirculated by a pump,or treated before discharge.

3.Key Features

Advantages

Superior Corrosion Resistance:PP material resists strong acids,alkalis,and chemicals;ideal for highly corrosive waste gases.

High Purification Efficiency:90–90%removal for soluble gases(HCl,SO₂)and 85–90%for fine dust(>5μm).

Low Maintenance:Anti‑clogging nozzles,no internal moving parts,easy to clean and repair.

Lightweight&Cost‑Effective:Lighter than FRP/stainless steel;lower material and installation costs.

Wide Operating Range:Handles gas flows from 500 to 50,000 m³/h;adaptable to low‑to‑medium pollutant concentrations.

Limitations

Temperature Limit:Continuous operation≤60°C;not for high‑temperature flue gas(>80°C).

Fine Particle Limit:Less effective for submicron particles(<5μm);often used with a pre‑filter.

Liquid Consumption:Requires 1–5 L/m³of gas;needs consistent water/chemical supply.

4.Applications

Chemical Industry:Remove HCl,Cl₂,SO₂,and organic vapors.

Electroplating&Pickling:Treat acid mist(HCl,H₂SO₄)and metal fumes.

Pharmaceuticals&Food:Control odors and volatile organic compounds(VOCs).

Waste Incineration:Neutralize acidic flue gases(HF,NOₓ).

Laboratories&Pilot Plants:Small‑scale gas scrubbing and odor control.