In the desulphurization process, the slurry atomizing nozzles in the absorption tower are all connected with flange, but there are some problems in the application of this connection.
 
For the absorber slurry atomizing nozzle, the coverage rate is usually calculated at the distance from the atomizing nozzle outlet LM. For wetting nozzles for packing and flushing nozzles for defogging, coverage is calculated at the surface of packing or defogging. In these cases, 200% to 300% coverage is typically required.
 
In the application of the flat atomizing nozzle, it is necessary to ensure a certain atomization coverage rate. Through the installation method, it can be guaranteed to have a certain atomization coverage rate.
 
Installation method of atomizing nozzle: the following ways are usually used to connect the atomizing nozzle to the slurry storage parent pipe. These methods include: conch connection, flange connection, mechanical coupling connection and adhesive connection.
 
1) Thread connection: thread connection is often used for R inch small atomizer washing water nozzle, vacuum belt machine filter cake washing nozzle and flue gas humidification cooling nozzle, rarely used for the larger size of atomizing slurry nozzle in the absorption tower. There are usually external threads on the nozzle and internal threads on the parent pipe.
 
2) Flange connection: when using flange connection. There are flanges with bolt holes on both the slurry master pipe and the nozzle as shown in Figure 2-44. This connection is often used for the connection of the slurry atomizing nozzle in the absorption tower. Usually each flange has four bolts. Bolts, nuts and washers for flange connections are made of nickel alloy to resist corrosion in the absorber.
 
Although most desulfurization systems in power plants and the slurry atomizing nozzles in the absorption tower of desulfurization process in power plants adopt flange connection, there are some problems in the use of this connection. The number of slurry atomizing nozzles in the absorption tower of a large FGD system can be as high as 1000, requiring at least 4000 sets of alloy bolts, nuts and washers, in addition to the high cost. In the process of installing the nozzle, these small connectors are also easy to fall from the height, and may be one of the factors that damage the nozzle. Second, in the installation process, if the bolt is too tight, it may damage the flange of the ceramic nozzle, in most cases, this is the main reason for the damage of the nozzle. Third, if the flange bolts of an atomizing nozzle are not tightened, there will be a leak at the flange joint, and the high-speed slurry jet from the leak will severely wear the nearby parts and be difficult to detect in advance. Finally, even if the alloy bolts, nuts and washers, running for a longer time, these bolts and nuts are difficult to remove. Removing these nuts that cannot be removed normally is another major cause of nozzle damage.