When your plant handles acid gases, toxic fumes, or odour-generating processes, the GPCB or CPCB Consent to Operate is non-negotiable. A correctly designed wet scrubber removes the pollutant at source, keeps your emission levels within prescribed limits, and protects your consent conditions. AS Engineers has been manufacturing industrial wet scrubbers for chemical, pharmaceutical, fertilizer, and water treatment plants across India since 1997. Every scrubber we build is engineered to the specific pollutant, gas volume, inlet concentration, and target outlet concentration of your process.

Types of Wet Scrubbers AS Engineers Manufactures

We manufacture two primary wet scrubber configurations. The right type depends on the pollutant, gas flow rate, inlet concentration, and the removal efficiency your process or consent order requires.

Packed Bed Scrubber (Packed Tower Scrubber)

In a packed bed scrubber, the contaminated gas rises upward through a bed of structured or random packing while scrubbing liquid flows downward from the top. The large contact surface created by the packing drives high absorption efficiency. Packed bed scrubbers are the preferred configuration for continuous acid gas duty: HCl from pickling lines, H2SO4 mist from sulfonation reactors, HF from fluorination processes, SO2 from boiler or incinerator exhausts, NH3 from fertilizer processes, and chlorine from bleaching operations.

MOC options: polypropylene (PP) body with PP or FRP internals for most acid services; MS construction with acid-resistant lining for specific applications; SS 304 or SS 316 where temperatures or regulatory requirements specify metallic construction.

Packing options: PP Pall rings, PP Raschig rings, structured PP or FRP packing. Packing selection affects pressure drop and mass transfer efficiency.

Venturi Scrubber

A venturi scrubber accelerates the gas stream through a converging throat where scrubbing liquid is injected at high velocity. The intense turbulence at the throat creates droplet-to-particle or droplet-to-gas contact. Venturi scrubbers handle particulate-laden gas streams and sticky or polymerising vapours that would foul a packed bed. They are less efficient for pure gas absorption than packed beds but tolerate dirty or dusty inlet conditions.

Applications: rubber processing fumes, foundry cupola exhaust, fertilizer granulator off-gases, furnace emissions with combined dust and fume load.

Pollutant-to-Scrubber Selection Reference

Materials of Construction by Service Severity

Wet scrubbers handle corrosive media. Material selection is a process safety and service life decision, not just a cost one.

• PP (Polypropylene): Standard choice for most acid gas and alkali scrubbing services below 60°C. Good chemical resistance, lightweight, easy to fabricate.
• FRP (Fibre Reinforced Plastic): Larger diameter vessels, higher structural strength, suitable for outdoor installation. Chemical liner selection matches the service.
• SS 304 / SS 316: Metallic construction where higher temperatures, mechanical loading, or specific regulatory requirements apply. SS 316 for chloride-containing services.
• MS with lining: MS shell with rubber or acid-resistant tile lining for heavy-duty, large-volume applications.

The System Integration Advantage

A wet scrubber does not operate in isolation. It requires a correctly selected centrifugal blower or ID fan to draw or push the gas stream through the system at the right volume flow and static pressure. If the blower is undersized, gas bypasses the scrubber. If it is oversized, the pressure balance across the packing is wrong and efficiency drops.

AS Engineers manufactures both wet scrubbers and centrifugal blowers under one roof. When you order a scrubber system from us, the ID fan or blower is selected by the same engineering team that designed the scrubber. Duty point, corrosion resistance requirement, impeller material, and seal arrangement are matched to the scrubber design. You get one set of GA drawings, one commissioning team, and one point of contact. Most scrubber-only manufacturers do not supply the blower. Most blower manufacturers do not supply the scrubber. We supply both, designed together.

Many wet scrubber systems also include a cyclone separator upstream to knock out coarse particulates before the gas enters the packed bed, protecting packing from premature fouling. Where downstream dry dust collection is also required, a bag filter can be integrated. AS Engineers manufactures all three as part of a complete pollution control equipment system.

Industries We Serve

• Chemical and specialty chemicals: acid gas control from reactors, storage vents, distillation overhead
• Pharmaceuticals: solvent vapour scrubbing, fume extraction from synthesis areas
• Fertilizers: NH3 recovery and SO2 control from granulators and reactors
• Metal finishing and electroplating: HCl and H2SO4 mist control from pickling baths
• Rubber processing: fume and odour control from mixers and vulcanisation lines
• Water and wastewater treatment: H2S and odour scrubbing from ETP/STP pump stations and tanks
• Paint and coatings: VOC and solvent vapour control
• Food processing: odour control from cooking, rendering, and fermentation operations

What You Need to Share for a Wet Scrubber Proposal

To generate an accurate scrubber design and proposal, our engineering team needs these eight data points. The more accurately you provide them, the tighter the proposal and the shorter the design cycle.

1. Pollutant name and chemical identity (e.g., HCl, SO2, H2S)
2. Gas flow rate (m³/hr or Nm³/hr at operating conditions)
3. Inlet concentration of pollutant (mg/Nm³ or ppm)
4. Required outlet concentration or removal efficiency (as per GPCB/CPCB consent order or internal target)
5. Gas temperature at scrubber inlet (°C)
6. Moisture content of inlet gas (if known)
7. Presence of particulates in the gas stream (yes/no, and approximate loading if known)
8. Available utilities: water supply pressure, chemical dosing capability, drain connection

Send us these details at info@theasengineers.com or call +91 99090 33851. Our engineers will come back with a preliminary design recommendation and indicative pricing within two working days.

AS Engineers: Scrubber Manufacturing Facts

• ISO 9001:2015 certified manufacturing, Ahmedabad
• In-house engineering: process design, mechanical design, fabrication
• Materials handled: PP, FRP, SS 304, SS 316, MS with lining
• Custom scrubbers for non-standard pollutant combinations or multi-stage duty
• Supply scope: scrubber vessel + packing + liquid distributor + mist eliminator + recirculation pump + associated piping, with or without the centrifugal blower
• Installation and commissioning support across India
• Spare parts and AMC contracts available post-commissioning

Frequently Asked Questions

What is the difference between a packed bed scrubber and a venturi scrubber?

A packed bed scrubber is the standard choice for gas absorption duty: it offers high removal efficiency (typically 90–99% for soluble acid gases) by maximising gas-liquid contact through packing media. A venturi scrubber is preferred when the inlet gas carries particulates, sticky vapours, or polymerising compounds that would foul a packed bed. Venturi scrubbers are more tolerant of dirty gas streams but achieve lower efficiency for pure gas absorption than packed beds.

Which scrubbing liquid should I use for acid gas removal?

It depends on the acid. Strongly acidic gases like HCl and HF are most efficiently removed with a dilute caustic (NaOH) solution because caustic neutralises the acid on contact, driving the absorption reaction. Alkaline gases like NH3 are removed with a dilute acid solution. H2S removal often uses NaOH with an oxidant. Water-only scrubbing is used for highly soluble gases like HCl when concentration requirements are less strict. Our engineers specify the scrubbing liquid and dosing concentration as part of the process design.

What MOC should I specify for a scrubber handling HCl fumes?

For HCl below 60°C, PP (polypropylene) is the standard and most cost-effective material of construction. FRP is preferred for larger vessels or outdoor duty where structural rigidity matters. SS 316 is specified when temperatures exceed the polypropylene limit or when the process also involves solvents that degrade PP. If chloride concentration is very high and the gas is hot, a specialist lining system on MS may be evaluated. AS Engineers will recommend MOC based on your specific operating conditions.

Do I need a separate blower or fan for my scrubber system?

Yes. Every wet scrubber requires a fan or blower to move the gas through the system. Most scrubbers operate under induced draft, meaning the centrifugal blower sits on the clean air outlet side and draws gas through the packed bed. In some cases, a forced draft arrangement is used. The blower duty point, impeller MOC, and seal type must match the scrubber design. AS Engineers manufactures centrifugal blowers and ID fans in-house and supplies them as part of the scrubber package, eliminating the interface problem between separately sourced equipment.

What is the typical lead time for a custom wet scrubber?

Lead time depends on diameter, MOC, and packing specification. Standard PP or FRP packed bed scrubbers in common sizes typically ship in 6–10 weeks from order confirmation and drawing approval. Complex multi-stage or metallic scrubbers may take 10–14 weeks. We will confirm the delivery schedule as part of the proposal. For urgent requirements, discuss your timeline with our team at the enquiry stage.

Request a Wet Scrubber Quote

Tell us your pollutant, gas flow rate, and required removal efficiency. Our engineering team will design the right scrubber system and provide a detailed proposal within two working days.

Request a Quote

Call: +91 99090 33851 | +91 82386 77554 Email: info@theasengineers.com