Product Overview

The EXL series vertical spray scrubber is specially designed for treating most water-soluble pollutants as well as acidic and alkaline industrial exhaust gases.

In addition to removing water-soluble gaseous contaminants, the system can also capture micron-sized and larger particulate matter. Its basic treatment principle is to bring the contaminated gas into full contact with a scrubbing liquid, transfer pollutants from the gas phase into the liquid phase, and then separate the purified gas from the contaminated liquid.

Under controlled temperature and pressure conditions, the circulating spray system delivers the washing liquid through high-pressure nozzles. High-efficiency packing material increases the gas-liquid contact area and helps atomize the liquid into fine droplets.

At the beginning of gas-liquid contact, pollutant dissolution and absorption are the dominant processes. As the concentration of absorbed pollutants in the washing liquid increases, the absorption rate gradually decreases while the desorption rate increases.

When the absorption and desorption rates become equal, the system reaches gas-liquid phase equilibrium and the net absorption process stops. At this stage, the saturated washing liquid should be replaced or treated. Otherwise, the absorbed pollutants may escape from the liquid phase and return to the gas phase.

For acid or alkaline exhaust gas treatment, the scrubber can be equipped with an automatic chemical dosing system. Sulfuric acid, alkaline solution or another suitable reagent is introduced into the circulating liquid to react rapidly with the target pollutants and improve neutralization efficiency.

Working Principle

The EXL vertical spray scrubber mainly consists of the tower body, spray sections, packing layers, mist elimination section, circulating-water piping, circulation tank and circulating pump.

The spray sections generally use spiral nozzles and high-efficiency packing materials such as Pall rings. Transparent inspection windows can be installed to allow convenient observation of the internal spray and packing conditions.

The mist elimination section can use swirl plates, Raschig rings or other demisting media to remove entrained water droplets from the treated gas.

The circulating pump can be selected from corrosion-resistant plastic pumps or stainless steel centrifugal pumps according to the washing-liquid composition and operating conditions.

Other components, including plastic piping, valves, support frames, inspection ladders and inlet ducts, can be customized according to project requirements.

The vertical spray scrubber is a counter-current gas-liquid absorption tower. Contaminated gas enters tangentially through the lower inlet and rapidly fills the inlet section under the action of the ventilation fan.

The gas then rises evenly through the flow-distribution section. In the spray zone, the absorption liquid is atomized through evenly arranged nozzles, forming fine droplets that fully mix and contact the rising gas.

During this contact process, soluble pollutants transfer into the liquid phase, while acidic or alkaline components react with the corresponding chemical solution.

The treated gas then passes through the mist eliminator to remove entrained droplets. Purified gas exits through the top outlet and is discharged through the exhaust stack after meeting the applicable emission requirements.

Treatment Process

Main Components

Key Features

• Efficient absorption and neutralization of toxic and harmful gases
• Dust collection efficiency can generally exceed 90% under suitable operating conditions
• Suitable for water-soluble, acidic and alkaline pollutants
• Stable and reliable performance
• Simple operation and convenient maintenance
• Can be used independently or as a pretreatment unit
• Optional packing and automatic chemical dosing systems
• Available treatment airflow from approximately 500 to 100,000 m³/h
• Long equipment service life and relatively low maintenance requirements
• Flexible tower materials available according to corrosion and temperature conditions
• Customized tower dimensions and process configurations available

Available Construction Materials

Applicable Pollutants

• Acidic exhaust gas
• Alkaline exhaust gas
• Water-soluble organic and inorganic pollutants
• Acid mist
• Ammonia and alkaline vapors
• Sulfur-containing gases
• Industrial odors
• Fine dust and particulate matter
• High-temperature dusty gas after suitable cooling treatment

Applicable Industries

• Chemical manufacturing
• Food processing
• Pharmaceutical production
• Electronics manufacturing
• Steel and metallurgical industries
• Non-ferrous metal processing
• Mining and mineral processing
• Industrial furnace exhaust treatment
• Pickling and metal surface treatment
• Electroplating production
• Battery manufacturing
• Laboratory exhaust systems
• Other industries generating soluble or corrosive exhaust gases

Installation Instructions

1. Install the vertical spray scrubber on a reinforced concrete foundation at least 150 mm above ground level. Separate concrete foundations should be prepared for the pump and fan where required.
2. Protect the equipment body, nozzles, packing, piping and other components from impact or damage during transportation and installation.
3. Depending on the equipment dimensions and transportation conditions, the scrubber may be delivered in sections and assembled on site.
4. For outdoor installation in cold climates, provide anti-freezing protection for the bottom circulation tank, water piping and pump during winter.
5. Fill the circulation tank with the required absorption liquid to the marked operating level before startup. Replenish the liquid during operation when necessary.
6. Reserve adequate space around the scrubber for inspection, cleaning, packing replacement and pump servicing.
7. Confirm that the fan, pump, valves, dosing system and electrical controls operate correctly before introducing contaminated gas.

Startup Procedure

1. Check the liquid level in the circulation tank.
2. Confirm that the spray nozzles, valves and piping are unobstructed.
3. Start the circulating pump and allow it to operate for approximately 2–3 minutes.
4. Confirm that the spray distribution is uniform.
5. Start the ventilation fan and gradually introduce the exhaust gas.
6. Check the pressure, liquid circulation, dosing condition and outlet gas quality.

Shutdown Procedure

1. Stop the ventilation fan first.
2. Allow the circulating pump to continue operating for approximately 1–2 minutes.
3. Stop the circulating pump.
4. Drain, replace or treat the washing liquid when required.

Operation and Maintenance

• Regularly check the pH value and pollutant concentration of the circulating liquid.
• Replace or treat the washing liquid when its absorption capacity reaches the specified limit.
• Inspect the outlet gas purification performance.
• Clean the spray nozzles when the spray pattern becomes uneven.
• Inspect the packing for blockage, fouling or deformation.
• Check the mist eliminator and clean it when pressure loss increases.
• Inspect the circulating pump, valves, piping and seals for leakage.
• Check the automatic chemical dosing system and chemical storage level.
• Maintain operation, cleaning and liquid-replacement records.

A comprehensive inspection is generally recommended after approximately 18–24 months of operation, depending on the actual working conditions. The spray piping, packing material, mist eliminator and liquid circulation system should be inspected and cleaned as necessary.

Selection Considerations

• Required treatment airflow
• Pollutant type and concentration
• Exhaust gas temperature and humidity
• Acidic or alkaline properties
• Dust and particulate concentration
• Required removal efficiency
• Suitable washing liquid and dosing chemicals
• Required tower construction material
• Available installation height and floor space
• Local emission and safety requirements

Why Choose ES Air EXL Series?

• Designed for water-soluble, acidic and alkaline industrial exhaust gas
• Combines gas absorption, chemical neutralization and dust collection
• Compact vertical structure saves floor space
• Multiple corrosion-resistant materials available
• Optional automatic dosing and pretreatment configurations
• Can be integrated with other exhaust gas treatment systems
• Customized engineering according to actual working conditions
• Simple operation and convenient maintenance

Frequently Asked Questions

What is a vertical spray scrubber?

A vertical spray scrubber is an industrial air-pollution-control device that uses a circulating liquid to absorb water-soluble gases, neutralize acidic or alkaline pollutants and capture particulate matter.

What pollutants can the EXL series treat?

The EXL series is suitable for many acidic gases, alkaline gases, water-soluble pollutants, industrial odors and micron-sized particulate matter.

Why is chemical dosing required?

Chemical dosing adjusts the washing-liquid chemistry and promotes rapid neutralization of acidic or alkaline pollutants.

What is the purpose of the packing layer?

The packing layer increases the gas-liquid contact area and improves mass-transfer and pollutant absorption efficiency.

What is the purpose of the mist eliminator?

The mist eliminator removes liquid droplets entrained in the treated gas before discharge.

When should the washing liquid be replaced?

The liquid should be replaced or treated when its pollutant concentration, pH or absorption capacity reaches the specified operating limit.

Can the scrubber be installed outdoors?

Yes. Outdoor installation is available, but rain protection and anti-freezing measures may be required according to the local climate.

Can ES Air customize the vertical spray scrubber?

Yes. ES Air can customize the tower according to airflow, pollutant composition, temperature, corrosion level, treatment efficiency, installation height and project requirements.

Customized Acid and Alkaline Exhaust Gas Treatment Solutions

ES Air provides vertical spray scrubbers and integrated industrial exhaust gas treatment systems for chemical, pharmaceutical, electronics, metal processing and other industrial applications.

Contact ES Air for working-condition evaluation, material selection, process design and customized scrubber solutions.

SEO Brief: The ES Air EXL Series Vertical Spray Scrubber is designed for water-soluble, acidic and alkaline industrial exhaust gas. It combines spray absorption, packing mass transfer, chemical neutralization and mist elimination to remove gaseous pollutants and particulate matter. Available in PP, FRP, Q235B carbon steel and SUS304 stainless steel, the system is suitable for chemical, pharmaceutical, electronics, metal processing, electroplating and industrial furnace applications.