Product Overview

The EXW series horizontal spray scrubber operates on the same fundamental principle as a vertical spray scrubber and is designed for treating most water-soluble pollutants, acidic exhaust gases and alkaline exhaust gases.

In addition to removing water-soluble gaseous pollutants, the system can also capture particulate matter larger than the micron level. Its basic treatment principle is to bring contaminated gas into full contact with a liquid absorbent, 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 absorption liquid through high-pressure nozzles. High-efficiency packing material promotes atomization and increases the gas-liquid contact area.

At the beginning of gas-liquid contact, pollutant dissolution and absorption dominate the mass-transfer process. As the pollutant concentration in the absorption 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 dissolution 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 acidic 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 automatically introduced into the circulating liquid to react rapidly with the target pollutants and improve neutralization efficiency.

Working Principle

The EXW horizontal spray scrubber mainly consists of the scrubber body, spray sections, mist elimination section, circulating-water piping and circulating pump.

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

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

During operation, contaminated gas enters the scrubber tangentially through the lower inlet. Driven by the ventilation fan, the gas rapidly fills the inlet chamber and then passes evenly through the flow-distribution section.

Inside the spray zone, the absorption liquid is atomized through evenly arranged nozzles. Fine droplets fully mix and contact the contaminated gas, allowing soluble pollutants and acidic or alkaline components to transfer into the liquid and undergo chemical reactions.

The treated gas then passes through the mist eliminator, where entrained liquid droplets are removed. The purified gas exits through the upper discharge duct and is released through the exhaust stack after meeting the applicable emission requirements.

Treatment Process

Main Components

Key Features

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

Available Construction Materials

Applicable Pollutants

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

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 surface-treatment lines
• Laboratory exhaust systems
• Battery and electroplating production
• Other industrial processes generating soluble or corrosive exhaust gases

Installation Instructions

1. Install the horizontal 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, piping and other components from impact or damage during transportation and installation.
3. Depending on the equipment size 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 circulation tank, water piping and pump during winter.
5. Fill the circulation tank with absorption liquid to the marked operating level before startup. Monitor and replenish the liquid during operation.
6. Reserve sufficient space around the equipment for inspection, maintenance, packing replacement and pump servicing.
7. Confirm that the fan, circulating pump, valves, chemical dosing system and electrical controls operate correctly before introducing contaminated gas.

Startup and Shutdown Procedure

Startup

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

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 or replace the absorption liquid when required.

Operation and Maintenance

• Regularly check the pH value, concentration and contamination level of the circulating liquid.
• Replace or treat the absorption liquid when it reaches the specified control limit.
• Inspect the purified gas quality at the outlet.
• Clean the spray nozzles if 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 dosing equipment and chemical storage level.
• Maintain records of liquid replacement, cleaning and equipment inspection.

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 circulation system should be inspected and cleaned as necessary.

Selection Considerations

The following information should be confirmed before equipment selection:

• Required treatment airflow
• Pollutant composition and concentration
• Exhaust gas temperature and humidity
• Acidic or alkaline properties of the gas
• Dust and particulate concentration
• Required removal efficiency
• Suitable absorption liquid and dosing chemicals
• Required construction material
• Available installation space
• Local discharge and safety requirements

Why Choose ES Air EXW Series?

• Designed for water-soluble, acidic and alkaline exhaust gas
• Combines gas absorption, chemical neutralization and dust collection
• Flexible airflow range from small to large industrial applications
• Multiple corrosion-resistant construction materials available
• Optional automatic dosing and pretreatment configurations
• Can be integrated with other industrial exhaust gas treatment systems
• Customized engineering according to actual working conditions
• Simple operation and convenient maintenance

Frequently Asked Questions

What is a horizontal spray scrubber?

A horizontal 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 EXW series treat?

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

Why is chemical dosing required?

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

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.

What is the purpose of the mist eliminator?

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

Can the scrubber treat dusty exhaust gas?

Yes. The system can capture micron-level particles, although the final configuration should be designed according to dust concentration, particle size and gas characteristics.

Can the equipment 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 horizontal spray scrubber?

Yes. ES Air can customize the equipment according to airflow, pollutant composition, temperature, corrosion level, treatment efficiency and installation conditions.

Customized Acid and Alkaline Exhaust Gas Treatment Solutions

ES Air provides horizontal 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 EXW Series Horizontal Spray Scrubber is designed for water-soluble, acidic and alkaline industrial exhaust gas. It combines spray absorption, chemical neutralization, packing mass transfer 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 and industrial furnace applications.