May 6, 2022

The role of desulfurization nozzles in flue gas desulfurization

The basic principle of desulphurization nozzle dust removal is to wet the dust particles with water spray to increase the particle size and specific gravity, and then separate them from the atmosphere or flue gas.

Different desulfurization processes use different nozzle forms. The material conveyed in the dry desulfurization process is desulfurization agent powder, generally using air flow nozzles. In the semi-dry desulfurization process, the limestone slurry is transported with high concentration and high viscosity. Generally, airflow nozzles are also used. The research shows that the air mass ratio and concentration are the main parameters affecting the average droplet size. The increase of the gas-liquid mass ratio leads to a decrease in the average SMD of the droplet: as the concentration increases, the SMD increases. In the wet desulfurization process, the nozzles are generally used for scrubbing the flue gas of the desulfurization scrubber, cleaning the blades of the demister, etc. The diameter of the spray droplets required by the process is generally 1300-3000pm. Considering factors such as energy consumption and nozzle friction, it is often used. Pressure nozzle.

gas desulfurization

For the pressure nozzle used in the wet flue gas desulfurization process, it is required that the components that make the liquid obtain rotary motion are as simple as possible, and because the required atomization particle size is large, a rotary pressure nozzle is generally used. On the basis of comprehensive economy and characteristics, the commonly used pressure nozzles in the desulfurization process mainly include solid cone swirl nozzles, hollow cone swirl nozzles, air cone spiral nozzles and solid cone spiral nozzles. Among them, the application of hollow cone swirl nozzle is the most common.

Because the position of the nozzle in the wet desulfurization process determines the importance of the research on the desulfurization nozzle, with the progress of the process research, the research on the nozzle is gradually deepened. Starting from the ideal fluid, the scholars deduce the series of relational expressions followed by the simple swirl nozzle through the correction of the turbulent resistance, and give the calculation method of the parameters of the simple swirl nozzle. The viscosity correction in the method still needs to be studied. At present, the application research of the pressure nozzle with limestone slurry as the medium is still less, and the research is generally carried out with water as the medium. The research on the flow field structure inside and outside the nozzle and the arrangement of the nozzle inside the spray tower is also rarely involved.

The desulfurization effect of silicon carbide nozzles will be affected by some factors during desulfurization and dust removal, resulting in a decrease in its use effect. What factors will adversely affect the desulfurization efficiency of silicon carbide nozzles?

The first is the atomization of the desulfurization nozzle. The small surface area of ​​the liquid provided by the limestone slurry after spraying will directly affect the desulfurization effect. When the inlet pressure of the silicon carbide nozzle is larger, the pressure drop of the nozzle is larger, and the flow through the nozzle is higher. Larger, and the smaller the uniform diameter of the spray droplets atomized by the nozzle.

Secondly, the spray droplet size distribution of the nozzle is very important for most applications. The silicon carbide nozzle sprays droplets with high uniformity of the optimal particle size, which can reduce investment and complete the economic operation of the system.

In addition, the factors that affect the desulfurization of silicon carbide nozzles are related to the nozzle flow rate, nozzle pressure drop, nozzle configuration parameters and other factors. The flow rate of silicon carbide nozzles will ultimately affect the economy of the desulfurization system. The selection of nozzles with large flow rates can reduce the total number of nozzles required, thereby reducing the cost of the system. Large-flow nozzles have less constraints and have good anti-clogging performance, which can effectively save money. Operation and maintenance costs. But at the same time the acceptable maximum flow measurement for different silicon carbide nozzles is constrained by the atomization of this nozzle.