AN series axial fan with adjustable stator blade
key word：Heat exchange element
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Product description
AN series axial fan with adjustable stationary blade
1. Introduction
1.1. Application
An adjustable static blade axial fan has the characteristics of high pressure head and large flow of axial flow fan, which is widely used in 100~1000MW power station in China and other countries. The fan is suitable for conveying large flow gas containing ash or corrosive, such as induced draft fan, forced draft fan, primary air fan and flue gas desulfurization booster fan. It can also be used for ventilation, cooling, exhaust and dust removal in mining, metallurgy, cement and other industries.
1.2. Model meaning (take AN30e6 as an example)
AN30e6（V19+4°）
A -- axial flow fan
N -- non wing type (plate type no)
30 --- machine number (R40 Series)
e -- a kind of leaf (eins in Germany, one in English)
V is the diameter of impeller of V-shaped blade (equal strength, high natural frequency and high pressure coefficient) plus 6 machine numbers to get the outlet size of diffuser
19 -- number of blades
4 ° --- installation angle
1.3. Structural features
AN static blade adjustable axial fan is a new type of fan researched and designed by KKK company of Germany for more than 50 years. It has advanced technology, high regulation efficiency, wide regulation range (from + 30 ° to - 75 °), compact structure, reliable operation and convenient installation and disassembly. An fan is designed with different blade installation angles, pot bottom hub and three-dimensional twisted blades, so that the air flow is evenly distributed in the impeller channel, which adapts to the incident angle of dust particles on the blade surface, and has good aerodynamic performance and wear resistance. Users generally reflect that it is safe, durable, efficient and energy-saving.
1.3.1. Characteristics of rotor. The impeller of AN fan adopts curve optimized equal strength blade; the intermediate shaft transmitting torque and power only does not bear the weight of impeller, so it adopts hollow structure and light weight. The rigid flexible diaphragm coupling connected at both ends can not only compensate the installation alignment error, but also compensate the influence of axial thermal expansion in operation; The main shaft of the fan is short with high rigidity, which can greatly improve the critical speed of the fan, and it is very convenient to disassemble and assemble. The disassembly and assembly steps for impeller maintenance are as follows:
1.3.1.1. Remove the top half of the casing.
1.3.1.2. Remove the shaft guard pipe and hollow short pipe.
1.3.1.3. Remove the impeller and bearing seat from this position.
The reassembly can be carried out in reverse order. It is very convenient to repair and replace the bearing. It is unnecessary to align the rotor when the impeller is reassembled.
1.3.2. Features of lubricating cooling system. The rolling bearing of AN fan adopts grease lubrication and ventilation cooling, without the need of thin oil station system and cooling water; the cooling system cools the main bearing assembly from inside to outside, and the cooling fan usually adopts one for standby and one for use. When the ambient temperature is high, the two units can operate at the same time. The investment and maintenance cost of AN fan is low, and the leakage of lubricating oil is completely eliminated, which is conducive to the environmental protection of power plant.
1.3.3. Wear resistance. The surface hardness of the blade can reach HRC55-60 by the key anti-wear treatment for the easily worn parts of the blade and the rear guide vane; the incidence angle and distribution uniformity of the flue gas abrasive particles on the blade surface are fully considered in the design of the flow passage of the impeller, so there is no blade root wear, and the rear guide vane is inserted structure, which is very convenient for maintenance and replacement.
1.4 working principle
An type static blade adjustable axial flow fan is also known as meridian acceleration fan. The starting motor drives the impeller to rotate and do work through the coupling and intermediate shaft, and the medium (gas) converges and accelerates on the meridian plane when passing through the impeller passage, so as to obtain kinetic energy. After being rectified by the rear guide vane, it enters the diffuser. At this time, the flow rate drops, and most of the kinetic energy is converted into static pressure energy, thus meeting the system requirements.
1.5. Product series
An type axial-flow fan with adjustable stationary blade includes 23 kinds of machine numbers from AN13 to AN50. Each type of fan can be divided into 4 kinds of blade numbers: 13, 15, 17 and 19. Each type of blade number can be divided into 4 kinds of blade installation angles. Therefore, it can meet the requirements of various parameters of users and select the fan with the best matching characteristics with the system working conditions.
2. Main technical parameters
The user shall provide the following technical parameters:
2.1. Unit capacity.
2.2. Type of fan application.
2.3. Local atmospheric pressure (Pa).
2.4. Local altitude (m)
2.5. Fan operating parameters under various working conditions:
2.5.1. Boiler load (%).
2.5.2. Mass flow rate (kg/s)
2.5.3. Standard flow rate (m3/s)
2.5.4. Fan inlet flow (m3/s).
2.5.5. Fan inlet temperature (℃).
2.5.6. Fan outlet temperature (℃)
2.5.7. Standard density (kg/m3)
2.5.8. Fan inlet density (kg/m3)
2.5.9. Static pressure at fan inlet (Pa)
2.5.10. Static pressure rise (Pa).
2.5.11. Muffler loss (Pa)
2.5.12. Total pressure rise (Pa).
2.6. Motor requirements and power supply voltage.
3. Equipment appearance and structure
The shape of an series axial fan with adjustable stationary blade is shown in Figure 10-1.
Figure 10-2 shows the characteristic curve of a typical AN fan. In the figure, A-line represents the stall line of general an fan, and B-line represents the stall line of an fan after the performance stabilizer (KSE) proprietary technology is added to the structure of AN fan. Due to the stall and surge problems of axial flow fans, if the type selection is not proper, the fans will be in unstable working state under low load operation. This problem was often solved by opening bypass in the past, but it brought many troubles to operation control and pipeline layout. However, the performance stabilizer (KSE) can solve this problem well. Its principle is that when the flow rate of the fan is too low, the reverse flow generated at the top of the blade will be diverted by KSE and then re enter the main channel, so as to avoid surge and expand the stable working range of the fan.
In the grid, + 30 ° to - 75 ° is the opening angle of the adjustable front guide vane, the performance curve without KSE device is the higher head (dotted line), and the performance curve after adding KSE device is the lower head (solid line).
4. Selection method
According to the parameters provided by the user, the manufacturer selects the type of microcomputer according to the specifications. Figure 10-3 shows the range of an fan parameters and selection examples. In the figure, the line family with r/min represents the various speeds of an fan; the straight line family with Φ represents the different diameters of the fan; and the shaded part indicates the range that the performance parameters of AN fan can cover. The curve in the figure shows the performance curve of AN fan of a certain specification selected.
The parameters given in AN fan selection example in Figure 10-3 are as follows:
Flow 250 m3/s
Medium density 1.1 g/m3
Total pressure rise 40 mbar
The selection (rough) method is that the dashed line is drawn upward at the flow point corresponding to the abscissa in the right figure, and the dotted line is drawn upward at the corresponding density point of the abscissa in the left figure, and the two intersect the 40mbar curve, and then the horizontal dotted line is made at the intersection point to intersect the dotted line in the figure. The results show that the impeller diameter is 2600 mm and the speed is 750 r/min.
5. Scope of supply
5.1. Scope of complete set of supply included in the price of each fan
5.1.1. Axial flow fan body with adjustable stator blade.
5.1.2. Rigid flexible coupling and intermediate shaft assembly (including shield).
5.1.3. 2 cooling fans (including muffler).
5.1.4. One set of cooling air duct and three-way baffle door.
5.1.5. One set of lubricating oil pipe and oil filling device.
5.1.6. There are 6 ~ 9 pieces of Pt-100 thermal resistance temperature measuring elements, 2 ~ 3 pieces of bearings for each.
5.1.7. One set of anchor bolt.
5.1.8. Special tools for main bearing disassembly.
5.2. Order items that can be added according to the user's requirements (ordering or supporting supply is allowed, the price is calculated separately)
5.2.1. Motor.
5.2.2. Electric actuator (for stator blade adjustment).
5.2.3. Vibration monitoring device is used for rotor vibration monitoring and alarm. It is basically equipped with one horizontal and one axial sensor for each fan, and each instrument monitors two fans.
5.2.4. Fan stall alarm device.
5.2.5. Local junction box (or instrument box with digital display meter).
5.2.6. Non metallic expansion joint at inlet and outlet.
5.2.7. Muffler (for forced draft fan).
5.3. Technical documents provided during supply
5.3.1. Operation instructions (attached with general installation drawing, main bearing assembly drawing, adjustable stator blade mechanism diagram, etc.).
5.3.2. Shipping list.
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