What is the working principle of fiberglass spray tower?

Fiberglass spray tower is a commonly used equipment for industrial waste gas treatment and dust control, and its working principle is mainly based on the following aspects:

Mass transfer in contact between gas and liquid

The spray tower is equipped with a spray system that evenly sprays liquid (usually water or specific absorbent) into small droplets through nozzles.

The exhaust gas containing pollutants enters from the bottom of the spray tower, flows from bottom to top, and comes into counter current contact with the liquid droplets from top to bottom. During this process, pollutant molecules in the exhaust gas collide with molecules on the surface of liquid droplets. Due to the intermolecular forces, pollutant molecules will transfer from the gas phase to the liquid phase, achieving mass transfer.

Washing and absorption effects

For some water-soluble pollutants, such as hydrogen chloride, ammonia, etc., water can be used as an absorbent to directly dissolve and absorb them. When the droplets come into full contact with the exhaust gas, pollutants will continuously dissolve into the water and be carried out of the spray tower with the flow of the liquid, thus achieving the purpose of purifying the exhaust gas.

For some pollutants that are difficult to dissolve in water, specific absorbents can be added to the water. For example, when treating exhaust gas containing sulfur dioxide, alkaline absorbents (such as sodium hydroxide solution) can be added. Sulfur dioxide reacts chemically with alkaline substances to generate water-soluble salts, which are then absorbed and removed.

Inertial collision and interception

When dust particles in exhaust gas move with the airflow, they will collide with liquid droplets due to inertia. Due to the mass and inertia of dust particles, they cannot easily follow the airflow around droplets like gas molecules when the direction of the airflow changes. Instead, they will directly collide with the droplets and be captured by them.

For some smaller dust particles, although their inertia is small, they will approach the droplet due to Brownian motion and be intercepted by the adhesion of the droplet surface when in contact with the droplet, thus separating from the exhaust gas.

gravity sedimentation

Dust particles captured by droplets or droplets that have absorbed pollutants will gradually sink under the action of gravity. Spray towers are typically designed with ample space and appropriate airflow velocity to allow liquid droplets sufficient time to settle into the collection pool at the bottom of the tower.

The liquid in the collection tank can be transported back to the spray system for recycling through a circulation pump, while a certain amount of wastewater is regularly discharged for treatment to ensure the purification effect of the absorption liquid.