In the application of boiler centrifugalInduced draft fanin addition to meeting the requirements of flow and wind pressure, the requirements for the efficient operation of centrifugal fans should also be considered, which is an important factor in the reasonable selection of fans. The performance of the fan is the basis for the reasonable selection of the fan, and the method of selecting the fan varies according to the different performance characteristics of the fan.

　　The selection of boiler centrifugal induced draft fans mainly includes the following methods:

　　1. Select the fan using the fan performance curve

　　This method is as simple as selecting a pump using the pump performance curve. This method facilitates the analysis of working condition adjustments and determining adjustment parameters. The comparison using performance curves is poor.

　　2. Based on the performance curve of the selected boiler centrifugal fan and the pipeline performance curve, consider the layout of the system pipeline and the operating mode of the fan, explaining the operating conditions of the device and the operating parameters of the fan.

　　3. If adjustments to the working conditions are needed, graphical adjustments should be made according to the adopted adjustment method, and the corresponding adjustment parameters should be determined. When multiple methods can be used for adjustments, an economic analysis of different methods should be conducted to determine a reasonable adjustment method.

　　3. Select the fan using the fan performance selection curve

　　This is a commonly used method for selecting boiler centrifugalInduced draft fanfans. The selection curve is the same for similar series with different impeller diameters. The relationship between total pressure, power, speed, and flow of each wind turbine is represented by a series of lines plotted on a logarithmic coordinate graph.

　　An induced draft fan is a machine that converts the mechanical energy of the prime mover into the energy of transporting gas. Induced draft fans are essential mechanical equipment in the flue gas purification system of the aluminum electrolysis industry, serving as the power source for flue gas flow, discharging purified flue gas into the atmosphere. Induced draft fans have a high failure rate. Statistics show that failures occur on average 42 times a year, leading to unplanned shutdowns or reduced load operations, affecting the purification effect of electrolysis flue gas. The types of fan failures are numerous, and the causes are complex. Based on practical experience, common failures of fans include excessive bearing vibration and high bearing temperature. Excessive bearing vibration in induced draft fans is a common failure during operation, which can cause damage to bearings and blades, loosen bolts, and damage the air duct, severely jeopardizing the safe operation of the fan.Induced draft fanHandling excessive bearing vibration.

　　When gas enters the impeller, it has a certain angle with the working surface of the rotating blades. According to fluid mechanics principles, vortices will form on the non-working surface of the blades, causing ash particles in the gas to slowly deposit on the non-working surface due to the action of the vortices. Airfoil blades are prone to dust accumulation. When the accumulated dust reaches a certain weight, some of it will be thrown out of the impeller due to the centrifugal force of the rotating impeller, leading to uneven dust accumulation on the blades and an unbalanced mass distribution of the impeller, thereby increasing the vibration of the fan.

　　In this case, the only way to reduce the fan's vibration is to remove the dust from the blades. The usual method is to open the inlet door of the fan housing after a temporary shutdown, allowing maintenance personnel to enter the housing to remove the dust from the impeller. At this time, a dynamic balance test needs to be performed after shutdown, using the point weighting method for simple and convenient dynamic balancing. The steps are as follows: Step 1: Remove dust or powder from the blades.