Detailed introduction:

The national drum, guide, and tunnel ventilation fans look to Zibo, and Zibo looks to "Fujiang" fans. After years of effort, Fujiang fans have developed a streamlined equipment system in the factory, including automatic CNC cutting, hydraulic shearing machines, automatic rolling and spinning, mold pressing at the fan inlet and front plate, and electromagnetic heating for bearing installation. Each fan sold by our factory undergoes strict start-up testing before leaving the factory to ensure the effectiveness and service life of each fan.

1. Y4-73 kiln induced draft fanScope of application

This fan is mainly suitable for the induced draft system of 2-670t/h steam kilns in thermal power plants. It can also be used for various dust removal, desulfurization, denitrification, and thermal energy systems. The medium transported is flue gas or hot air, generally not exceeding 250 ℃. Customization of high-temperature resistant materials is required for temperatures exceeding 250 ° C. The fan with F transmission mode is equipped for 100-200MW thermal power generation units and is produced in the original Y4-73-11 No. (20-29.5）On the basis of D, a new product has been redesigned. Compared with the original series, significant improvements have been made in the following design:
1) The transmission mode of the original fan cantilever support (D type) has been changed to the transmission mode of the intermediate support (F type), which improves the stability of the fan during operation; Especially for induced draft fans, the wear and dust accumulation of the impeller can affect the balance of the rotor and easily cause fan vibration. This improvement is particularly important.
2) Through model testing (impeller outer diameter D=1000mm), an intake chamber suitable for this type of fan has been added, and the shape of the original intake port has been changed to an eccentric intake port. In the past, fan manufacturers did not manufacture additional air inlet chambers, and the air inlet chambers configured by each power plant were often not suitable for the operation of the fan, which could easily cause intake vortices and cause severe vibrations in the fan casing, air inlet chamber, and air duct. The fan's operation deteriorated severely, with large fluctuations in air volume, pressure, and power, making the equipment unable to operate normally. Before using this system on the induced draft fan, a dust removal device must be installed to minimize the dust content of the flue gas entering the fan as much as possible. According to the usage of general power plants, the efficiency of the equipped dust collector shall not be lower than 85%.
3) There are 5 wing shaped blade regulating dampers installed at the inlet of the intake chamber to adjust the characteristics of the fan and improve its regulation efficiency. Rolling bearings are installed at the support of the regulating blades for flexible rotation and reliable use.
4) Due to the high ambient temperature of most air supply fans, the bearings are prone to heating up. Therefore, the bearing box of the new series of fans is also water-cooled, just like the induced draft fan.
5) The bearing box of the fresh air fan has improved the shaft seal design and added a vent plug to solve the oil leakage problem.
6) Due to the change in the standard of rolling bearings, the model of rolling bearings used in the fresh air fan has been adjusted. At the same time, due to the change in transmission mode and the more reasonable bearing capacity of the shaft, the problems of rolling bearings in use have been greatly reduced.
7) The design of the fresh air fan enhances the rigidity of the casing and intake chamber. A well shaped grid plate of appropriate height is welded on the outside of the intake chamber of the casing, and a hollow tube support is welded on the inside, thus eliminating the vibration caused by insufficient rigidity of the casing.
8) Considering the issue of dust particle wear on the impeller of the induced draft fan, the solid part of the wing shaped blade head has been increased, and an anti-wear plate has been added at the rear plate of the blade. At the same time, wear-resistant welding rods have been used to weld wear-resistant layers at the easily worn areas, with a hardness of over 48HRC, which extends the service life of the impeller and meets the requirements of power plant use and maintenance.
9) According to the actual situation, the fresh air fan is designed with an inlet angle of 135 degrees and an outlet angle of 45 degrees. This way, without moving the main body and inlet and outlet ducts of the fan, a part of the fan casing, inlet chamber, and inlet can be removed, and the rotor of the fan can be vertically lifted out from the top.

2. Y4-73 kiln induced draft fanThe type

·The ventilation fan and induced draft fan are both made into single suction units, with 19 machine numbers ranging from No. 8-31.5 each.
·From one end of the motor, if the impeller rotates clockwise, it is called a right cyclone machine, represented by "right"; On the contrary, it is the left cyclone machine, represented by "left".
·The position of the air outlet of the fan is represented by the angle of the air outlet of the casing.
·The transmission mode of the fan is D-type, all of which are connected by elastic couplings.

3. The structure of the fan

The Y4-73 fan with D-type transmission is mainly composed of an impeller, a casing, an air inlet, a regulating door, and a transmission part.
·Impeller -12 angled angled blades are welded between the conical front plate and the flat rear plate. Due to the use of wing shaped blades, the main efficiency, low noise, and high intensity of the fan are ensured. The impeller has undergone static and dynamic balance correction and overspeed operation test, so it runs smoothly and reliably. The impellers of ventilation fans and induced draft fans with the same machine number have the same structure but different materials. Generally, A3 is selected for ventilation fans and 16Mn is selected for induced draft fans
·Shell - welded into a snail shape with ordinary steel plates. The casing of the single suction fan is made in three different forms (the casing of No. 8-12 is made as a whole structure and cannot be disassembled, the casing of No. 14-16 is made as a two open type, and the casing of No. 18-29.5 is made as a three open type). The volute plate of the induced draft fan has been appropriately thickened to prevent wear and tear.
·Air inlet - The convergent and streamlined air inlet is made into a whole structure and fixed to the inlet side of the fan with bolts.
·Regulating door - a device used to regulate flow, installed axially before the air inlet. The adjustment range is from 0 degrees (fully open) to 90 degrees (fully closed). Position of the handle for adjusting the door: viewed from the air inlet direction on the right side, for the right cyclone machine, pushing the handle from bottom to top is in the fully closed to fully open direction, and for the left cyclone machine, pulling the handle from top to bottom is in the fully closed to fully open direction.
·Transmission - The main shaft of the transmission part is made of high-quality steel, and this fan uses rolling bearings. There are two forms of bearing boxes: Type 8-16 uses integral cylindrical bearing boxes; Use two independent pillow type bearing housings for No. 18-29.5. The bearing box is equipped with a thermometer and an oil level indicator (only for the induced draft fan). Lubricating oil adopts No.30 mechanical oil, and the amount of oil added shall be in accordance with the oil level indication requirements. If dry oil is used for the integral cylindrical bearing box of No. 8-16, an oil baffle should be added on one side of the ball in the bearing box, and its fixing groove should be made. The induced draft fan is equipped with a water cooling device, therefore, a water supply pipe must be added, and the water consumption varies with the temperature, generally considered at 0.5-1m3/h.

IIY4-73 kiln induced draft fanSpecification, Model and Performance Technical Parameters Table (Medium Temperature=200 degrees Celsius)

IIIY4-73 kiln induced draft fanInstallation, debugging, and operation

Before installation, the necessary materials and tools should be prepared, and all parts of the fan should be inspected. The impeller, main shaft, and bearings should be carefully checked. If any damage is found, it should be repaired, and then the inside of the bearing box should be cleaned with kerosene.
During the installation process, the following points must be noted:
1. On some joint surfaces, to prevent rust and reduce disassembly difficulties, lubricating grease or engine oil should be applied.
2. When installing bolts on the mating surface, if there are positioning pins, they should be installed first and then tightened.
3. Check the inside of the casing and other casings for any tools or debris that may have fallen or been left behind.
（2） Installation requirements
1. Install according to the position and size shown on the drawing, and in order to achieve high efficiency, it is particularly important to ensure the gap size between the air inlet and the impeller.
2. Ensure the horizontal position of the spindle and measure the concentricity between the spindle and the motor shaft, as well as the non parallelism at both ends of the coupling. The allowable deviation for non parallelism of the two axes is 0.05mm, and the allowable deviation for non parallelism of the two end faces of the coupling is 0.05mm
3. When installing the regulating valve, be careful not to install it in reverse and ensure that the intake direction is consistent with the rotation direction of the impeller.
4. After installing the fan, turn the rotor and check for any tightness or scraping with the fixed parts.
5. When installing the inlet and outlet pipes of the fan, the weight should not be added to the casing.
6. After full installation, it can only be put into trial operation after overall inspection.
（2） Trial operation of the fan
1. The trial operation of the fan should be carried out without load (closing the intake pipe gate or regulating valve).
2. If the operation is good, then switch to full load (specified full pressure and flow) operation.
3. Operate at full load for no less than 2 hours for newly installed fans and no less than half an hour for repaired fans
（3） Operation of the fan
1. When starting the fan, the following preparations should be made:
Close the regulating door.
Check the gap dimensions of each part of the fan and whether there is any scraping between the rotating and fixed parts.
Couplings should be equipped with protective covers.
Check if the oil level of the bearing is between the highest and lowest oil levels.
Check whether the impeller rotation direction is consistent with the label, whether the wiring and instrument display of each part are normal, whether there is water leakage, electric leakage, oil leakage, odor, abnormal noise, vibration, looseness and other phenomena. If there are any, they should be eliminated.
2. After the fan is started, gradually open the regulating valve until it reaches normal operating conditions. During operation, the temperature rise of the bearing shall not exceed 40 ℃ of the surrounding environment. The root mean square vibration velocity value of the bearing part shall not exceed 6.3mm/s.
3. Emergency parking is required in the following situations:
Detected severe noise from the fan;
The temperature of the bearing rises sharply;
The fan experiences severe vibration and impact.

four、Y4-73 kiln induced draft fanAir volume regulation

After the installation of the fresh air fan, excessive or insufficient flow occurs during operation, and the main reasons are as follows:
(1) The actual resistance value of the pipeline network differs significantly from the calculated value. The general equation for duct air characteristics is P=KQ2, where K represents the resistance coefficient. If the actual value K is less than the calculated value K, the flow rate increases; otherwise, the flow rate decreases.
(2) When selecting, the influence of the total pressure deviation Δ P of the fan itself was not considered. When the actual total pressure of the fan is a positive deviation, the flow rate increases, and when it is a negative deviation, the flow rate decreases.
After the installation of the fresh air fan, when it starts to operate officially, or when there is excessive or insufficient flow during use, one of the following methods can be used to eliminate it:
(1) Adjust the flow rate by adjusting the opening and closing degree of the regulating door.
(2) Adjust the flow rate by changing the fan speed.
(3) Replace the fan with a higher or lower pressure to adjust the flow rate.
(4) Adjust the flow rate by changing the resistance coefficient of the pipeline network.
It must be pointed out that throttling devices are generally used to regulate flow, but when the actual flow is much larger than the required flow, this method wastes too much electricity and is not economical. If conditions permit, it is usually necessary to reduce the fan speed or replace the fan with a lower pressure one.
When the regulating valve is fully opened, the flow rate is still too small. At this time, efforts should be made to reduce the resistance coefficient of the pipeline network to increase the flow rate. It is also possible to increase the fan speed and switch to a fan with higher pressure, but the maximum speed of the fan should not exceed the maximum speed on the performance table.
The performance of a fan generally refers to its ability to deliver air under standard conditions. The specified state of the induced draft fan is atmospheric pressure Pa=101300Pa, gas temperature t=200 ℃, and gas density ρ=0.745kg/m3. The performance in the performance table refers to adjusting the blades to fully open at 0 degrees. Please refer to the performance chart when placing an order.
When the actual usage state does not match the specified state mentioned above, the performance of the actual usage state must be converted to the performance of the specified state, and then the fan must be selected based on the converted performance. The conversion formula is as follows:
Q 0 = q? (m 3 / h)? P 0 = P? (PA)
Pin0=Pin??? (KW)???????? ηin0=ηin
In the formula:
N - Speed (r/min)? η in - internal efficiency, with footnote 0 indicating the specified state and footnote 0 indicating the usage state

5、 Y4-73 kiln induced draft fanMaintenance of

（1） Wind turbine maintenance work system
1. The fan must be used and maintained by a dedicated person.
2. Fans are not allowed to operate with defects.
3. Regularly remove dust inside the fan, especially impurities such as dust and dirt on the impeller, to prevent rust and imbalance.
4. Wind turbine maintenance must emphasize the importance of first shutting down the power supply and stopping the machine.
（2） Precautions for normal operation of the fan
1. If excessive flow is found or a smaller flow is needed in a short period of time, the regulating valve can be used for adjustment.
2. Regularly check the sensitivity of thermometers and oil gauges.
3. Normally, lubricating oil should be replaced every 3-6 months, except after each disassembly and repair.
（3） Main faults and causes of fans
1. Severe vibration of bearing box
The fan shaft and motor shaft are not concentric, and the coupling is installed crooked;
Friction between the casing or air inlet and the impeller;
The stiffness of the foundation is not firm;
Loose rivets on the impeller or deformation of the impeller;
The impeller shaft and shaft are loose, or the coupling bolts are loose;
Loose connecting bolts between the casing and bracket, bearing box and bracket, bearing box cover and seat, etc;
Poor installation of fan inlet and outlet pipelines;
Rotor imbalance;
The blades of the induced draft fan are worn.
2. The temperature rise of the bearing is too high
Severe vibration of the bearing box;
Poor quality, deterioration, excessive dust, sand, dirt and other impurities in lubricating grease;
The tightening force of the connecting bolts of the bearing box cover and seat is too high or too low;
The installation of the shaft and rolling bearings is skewed, and the front and rear bearings are not concentric;
The rolling bearing is damaged.
3. Motor current too high or temperature rise too high
The intake pipe gate or throttle valve is not tightly closed while driving;
The traffic exceeds the specified value;
The density of gas transported by the fan is too high or viscous substances are present;
The input voltage of the motor is too low or there is a single-phase power outage;
The coupling connection is not correct, the leather ring is too tight or the gap is uneven;
Affected by severe vibration of the bearing box.