October 26, 2023

Selection criteria for nozzles used for denitrification

Selection of denitrification nozzles is a very important part of the flue gas denitrification project, the rationality and reliability of its selection directly affects the performance and stability of the entire denitrification system.
In order to ensure the selection of denitrification nozzles is successful, we need to consider the following aspects.

gas desulfurization nozzle

Type of nozzle

Denitrification nozzle according to the spray form is mainly divided into two kinds of solid nozzle and hollow nozzle.
The droplets of the solid nozzle are thicker and the spraying angle is smaller, it mainly relies on the impact force of the droplets to disperse the flue gas, which is suitable for the occasions where the droplets can fully react with the flue gas after mixing.
The droplets of the hollow nozzle are finer and the spraying angle is larger, which is suitable for the occasions when the droplets cannot fully react after mixing with the flue gas and the reaction time needs to be extended.

Material of nozzle

The material of the denitrification nozzle should be corrosion-resistant, abrasion-resistant and high-temperature-resistant, and the machining process and manufacturing cost of the nozzle also need to be considered.
Commonly used materials for nozzles include stainless steel, nickel-based alloys, and ceramics.
Stainless steel has good corrosion and high temperature resistance, but poor wear resistance.
Nickel-based alloys offer high hardness and wear resistance, but are more expensive.
Ceramics have better corrosion and abrasion resistance, but are easily broken.

Flow rate of nozzle

The flow rate has a direct impact on the distribution and speed of the droplets in the flue gas, which affects the performance of the entire denitrification system.
Too large a flow rate can lead to uneven droplet distribution and insufficient reaction time between the droplets and the flue gas. A lower flow rate results in a denser distribution of droplets, which can lead to droplet buildup and clogging.
When selecting the flow rate of the nozzle, it needs to be reasonably matched to the actual operating conditions.

Working pressure of nozzle

Important factors affecting the distribution and velocity of droplets in the flue gas. The higher the pressure the larger the droplets, which is not favorable for the reaction. The lower the pressure, the denser the droplet distribution, which causes clogging easily.
When selecting the nozzle operating pressure, factors such as droplet size, distribution and reaction time need to be considered.

Installation of nozzle

There are two main types of installation: vertical and horizontal.
Vertical installation allows the droplets to spread out and evenly distribute in the flue gas, suitable for applications where the flue gas is vertically upward.
Horizontal installation enables the droplets to be evenly distributed in the flue gas and move in the direction of flue gas flow, suitable for applications where the flue gas flows horizontally.

The selection of denitrification nozzles requires comprehensive consideration from the above aspects to ensure the performance and stability of the entire denitrification system. During the selection process, it is necessary to fully understand and analyze the actual operating conditions, and then make reasonable matching and optimization according to the analysis results. Only in this way can we ensure the maximum economic and social benefits of denitrification projects.

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