Wet Scrubber Nozzle: How It Works, Types, Materials, Selection

Author: Michael Klepik, Chief Executive Officer

The scrubber comprises multiple irrigation layers, typically one, two, or three. The entry of contaminated gas occurs tangentially in its entry chamber. As the gas rotates, it moves the liquid in the chamber, and some of it goes further into the system. Subsequently, as it encounters the flow of fresh washing liquid, an intensive mass-exchange process initiates between the gas and the liquid through irrigation.

The irrigation system is structured based on the technical characteristics of the purified fluid, featuring an irrigation area essential for facilitating an efficient fluid-liquid mass-exchange process.

The liquid phase, representing the contaminated solution, circulates within a designated cavity for subsequent reuse or removal, while the purified gas, together with eliminated liquid droplets, proceeds to the droplet eliminator. Following this stage, the clean air is released to the exterior.

Each type of scrubber nozzle has its unique characteristics and applications, and the choice of the appropriate type depends on the specific conditions of the gas cleaning process and the requirements for cleaning efficiency.

Sprayers are used to atomize liquid into fine droplets or a fine mist.

Wet scrubber spray nozzles are the most efficient means of purifying the air from various pollutants, including aerosols, and particles. They are particularly useful for removing the following types of air pollutants:

• The Spray Tower Scrubber ensures the highly effective removal of vapors such as hydrogen sulfide (H2S), ammonia (NH3), nitrogen oxides (NOx), and other harmful substances.
• Capable of efficiently capturing aerosols, including acidic aerosols and mists that may contain hazardous chemical substances.
• Help eliminate the tiniest particles (PM2.5 and PM10), which can include toxic substances and metallic pollutants.
• Ideal for capturing pollutants emitted during industrial processes, including dust, smoke, vapors.

The effectiveness of scrubber spray nozzles lies in their ability to maximize contact between pollutant particles and the cleansing solution, ensuring more efficient removal of harmful substances from the air.

Scrubbers equipped with nozzles:

• Spiral device with a vortex motion that generates a spiral flow of the cleansing solution, providing effective mixing with liquids.
• Conical sprayers that create a conical flow of sprayed solution. They can be used for wide distribution of the solution in the target area.
• Flat fan nozzles create a flat flow of sprayed solution. They can be useful for treating specific shapes or surfaces. It produces a fan-shaped spray with medium and small-sized droplets. Even when adjusting the liquid flow rate and pressure, it maintains a uniform spray structure. It is resistant to clogging.
• Vortex concentrate sprayer that creates a vortex flow of the solution. They can be used for effective mixing of gases with the cleansing solution.
• Impact emitters that create a high-velocity flow of liquid, which can be useful for removing heavy particles.
• Spray nozzles designed for the uniform distribution of the cleansing solution in the target area.

Concentrate sprayers are selected based on the density of irrigation and the composition of contaminants. If there is dust and large pollutants, it is recommended to use a non-clogging (flat-fan) device; if the goal is to achieve a minimum droplet size, then another suitable design is chosen.

Sprayers can be made from various materials depending on the requirements for chemical resistance, temperature, pressure, and abrasiveness of the environment.

• Stainless steel (304 or 316) is widely used due to its high corrosion resistance. It is suitable for most industrial applications and has good mechanical strength.
• Ceramics are typically made from aluminum oxides or silicon carbides. They have high corrosion resistance and abrasion resistance, making them an ideal choice for aggressive environments and high temperatures in scrubber nozzle application ceramic gas nozzle.
• Titanium has excellent corrosion resistance, especially in chemically aggressive environments. They are lightweight yet strong and suitable for various operating conditions.
• Plastic materials such as polypropylene (PP) or polyvinyl chloride (PVC) can offer good chemical resistance and are suitable for light industrial tasks.
• Polyurethane can be used for abrasive media and provide good resistance to wear and aggressive substances.

The choice of material depends on the specific operating conditions and the chemical properties of the gases or liquids being cleaned.

An FGD (Flue Gas Desulfurization) spray tower scrubber is specifically designed for use in systems that remove sulfur oxides from flue gases, such as FGD systems.

FGD scrubber nozzles are typically engineered to ensure efficient mixing of vapors and liquids, enhancing the process of sulfur removal from flue gases. They can come in various shapes and designs depending on the specific requirements of the FGD system and operating conditions.

Their primary purpose is to facilitate optimal contact between flue emissions and the solution for the effective removal of sulfur oxides and other pollutants from the gas streams.

FGD spray scrubber nozzles are essential in power plants, industrial factories, refineries, waste incineration plants, steel mills, pulp and paper mills, and cement plants to control emissions of sulfur and other pollutants.

The main technical characteristics of wet gas scrubber nozzles may include the following parameters:

1. The amount of solution that a sprayer can disperse in a specific amount of time, usually expressed in liters per minute (LPM) or gallons per minute (GPM).
2. The pressure at which the cleansing solution is delivered before it is sprayed. It is measured in bars or pounds per square inch (psi).
3. The angle at which the solution is dispersed. Different sprayers can have various spray patterns, such as 15°, 30°, 60°, and so forth.
4. The size of the droplets of the solution after spraying. It can be expressed in microns (μm) or inches. Smaller droplets can provide more effective contact, improving the cleaning process.
5. The type of material from which the spout is made, including stainless steel, ceramic, titanium, plastic, and others, depending on chemical resistance and strength requirements.
6. The type of connection the spout has to the pipeline or purification system. It can be threaded, flanged, or have other configurations.

These characteristics play a crucial role in selecting the appropriate concentrate sprayer for specific applications in cleansing systems as they influence cleaning efficiency and resource consumption.