Purpose and characteristics of the fan
Model Y5-48 centrifugal fan is generally used for1-20t/h industrial boilers with provincial gas(preheater) and dust removal equipment. If the inlet condition is similar, the performance and the adaptor can be used. The temperature of the delivered medium shall normally not exceed 250℃ (not exceed 300℃ maximum).
In front of the induced draft fan must be equipped with dust removal efficiency of not less than 85% so the dust removal device, in order to reduce the flue gas dust content into the fan, not only reduce the flue gas to the environment pollution, and reduce the smoke on fan wear, favorable to improve the service life of fan.
Type of fan
1. The fan is made as a single suction and its driving is A type. There are more than 10 types of fan numbers which are4、4.5、5、6、6.3、8、9、10、12.5、14、14.5、、and 16.
2. The fan can be made of 2 types of rotation i.e, right and left. Viewing from one end of the motor, it is called as clock-wise fan if the impeller rotates clock-wise, shown as “right”, On the contrary, it is called as counter-clock-wise fan if the impeller rotates counter-clock-wise, shown as “left”.
3. The outlet position of the fan can be expressed from the outlet angle of the casing. It can be made 7 kinds of angles which are 0°, 45°,90°, 135°,180°,225°, 270°，from both “Right” and “left”.
4. There are 3 driving modes: A, C, D:
A—Shaft disc of fan is installed on motor shaft by keyway, i.e. motor directly connecting;
C—Cantilever bearing unit, belt driving, but the pulley is outside the bearing;
D—Cantilever bearing unit, coupling directly driving.
Structure of the fan
The fan mainly consists of impeller, casing inlet, Driving and Bracket unit.
Casing: to be welded into a volute with normal steel plate.
Impeller: The fan blade is made up of 12 backward single leaf blades, which reduces the impact of the air flow, has good stability , and the motor is not easy to overload, which greatly prolongs the service life of the fan. This type of fan has high pressure coefficient, low speed and low noise, so its practicability is good. The maximum circumference speed of impeller diffuser shall not exceed 140m/s. The impeller, after being shaped, shall be balanced statically and dynamicaly and thus it guarantees a smooth operation.
Inlet: to be integrated into a convergent streamlined structure and bolted on the inlet side of fan.
Adjusting valve: a device used to regulate the flow rate of the fan, which is mounted at the front of the inlet. The adjustment range is from 0 degrees (full open) to 90 degrees (full closed). The switch position of the door is adjusted from the inlet direction to the right, and the right whirlwind machine is pulled from down to up direction from the bottom to the full open direction. For the left whirlfan , the wrench is pulled up from the top to the full open direction.
Driving unit—it consists of shaft, bearing box, rolling bearing, belt pulley or coupling.
Leakproof oil bearing box, the use of a joint type of oil ring to swing the high-speed rotating bearing oil to the inner wall of the bearing box flow back to the oil pool; In addition to convenient maintenance and preventing friction accidents, semi-open aluminum oil seal can be used to cut back some of the dilute oil along the shaft. The lateral pressure plate root blocks a small amount of dilute oil; The upper part of the bearing box is equipped with a ventilation plug to reduce the micro-positive pressure in the bearing box, ensuring no oil leakage and good dust protection performance.
Th e main shaft of the transmission part is made of high-quality steel. The fans are all rolling bearings and are lubricated with L-AN46 mechanical oil.
The fan is integrated or partitioned: the fan is disassembled and assembled into multiple components for transportation and installation.
The fan is convenient for installation and repair. The fan has two complete base shell and transmission group. The shell has a middle or vertical side. The disassembly is particularly convenient. The rotor can be lifted vertically. If only the impeller is replaced, it can also be disassembled axially.
Transmission mode: The fan is cantilever structure, convenient layout, belt wheel connection transmission, uniform transmission
Performance and selection of the fan
Performance of the fan:The performance of the fan is expressed by the parameters of fan flow, full pressure, spindle speed, shaft power and so on. Performance curve and the performance of the performance given in the table. Blower performance:200 degrees Celsius, atmospheric pressure is 101325 Pascal,Gas density is 0.745kg/m³, calculation and calculation of air medium. (Other designs are similar to the use of parameters.)
The performance of both the selection curve and the performance table refers to the performance of adjusting the blade to a full 0 degree centigrade. When ordering the performance table shall prevail. Fan performance test total pressure value of 5% of the total pressure deviation is less than design value.
Such as fan using condition does not accord with the above, the performance shall be carried out according to the related formula conversion.
When excessive or insufficient flow of processing. When use, often occur the phenomenon of excessive or insufficient flow, produce a lot of reasons for this phenomenon, if it is in use process flow occurs when small phenomenon, is mainly due to the resistance of pipe network. If it is in use process, after a long time to reduce gradually, mainly due to network congestion.
After the fan is a new installation, a formal operation occurs when the flow phenomenon of excessive or insufficient reason mainly has the following points:
1. The actual value and calculating value difference is too large in the resistance of pipelines.
By the general network characteristic equation: P = Kq2, type of K - drag coefficient.
If the actual value K is less than the calculated value K, increases the flow, if the actual value K is greater than the calculated value K, the flow decreases.
2. when the choice is not the fan itself fully considering the influence of the pressure deviation of δP, when the fan actual total pressure for positive deviation, then the flow; Negative deviation, the flow rate decreases.
Began formal operation after fan is a new installation, or in use process flow is too big or too small, one of the following methods can be used to eliminate it.
Make use of the fan speed adjusting flow increase or decrease.
Using the new high or low pressure switch to increase or decrease in flow rate of fan.
Change the pipeline resistance coefficient K to change traffic.
At this time to try to change the network reduce drag coefficient to increase traffic, also can increase the fan rotation speed and changing the high pressure fan, but speed shall not be greater than the maximum speed performance table.
The basis and the shape of the fan
Y5-48 type fan shape and see the appended drawings
Installation and operation of the fan
Before installation: Check all components of the fan to see weather any thing is missed; weather the impeller rotates in the same direction as the casing; weather all components are connected tightly and weather the impeller rotates freely.
During installation: Pay attention to check the casing and any tools or goods should not be dropped and remained inside the casing. The connecting face between the support of the fan and the foundation or between pads and foundation should be tight. Adjusting should be made to joint the fan with foundation surface and to connect the fan with suction, discharge duct naturally. Forced assembling, especially, applying weight of pipes on any components of the fan isimpermissible. Also, attention shall be paid to the horizontality of the fan.
Requirement of installation:
1. Install the fan according to the position and sizes shown on the drawing. To insure high efficiency, radial and axial clearances between inlet and impeller must be guaranteed.
2. After installation, turn, with a little force, the driving rotor to see if it is over tight or touched with stationary components.
3. Commission Can only be carried out after the unit is through the final inspection.
4. In order to prevent the motor being burnt out due to overloading, the fan can only be started up and tested without loading. If the case is ok, increase the load step by step until the rated operating condition is reached. Control the current strictly during operation to prevent it exceeding the rated value.
Operation of the fan:
Before starting-up, the following preparations shall be made:
1) Close the valve of suction pipe and open a little the valve on discharge pipe.
2) Check the rotating and non –rotating parts to prevent colliding and friction.
3) After the fan is started-up and the normal speed is reached, check the bearing temperature is normal or not during the operation. If there is no special requirement for bearing temperature, the temperature rise of the bearing shall not exceed 40℃ of surrounding temperature. The value of even root vibration speed of the bearing shall comply with the following rules: rigid support(support is fixed on the foundation) Vrms≤4.6mm/s; flexible support(be set onfoundation or floor through absorber) Vrms≤7.1mm/s. In case that severe vibration, colliding, quick rise of bearing temperature and other abnormal phenomena are found, stop the fan immediately.
Maintenance of the fan
1. Don’t allow fan with trouble running.
2. Don’t freely change the maintenance person, specific person operating and repair the fan is preferred.
3. Regularly remove dust, contamination and the foreign materials and prevent rust .
4. Maintenance can be carried out during shut down of fan to assure operators safety.
5. When the fan is repaired, the motor switch must be monitored or locked.
6. Inspect the thermometer and oil indicator regularly.
7. During the star-up, shut-down or operation of the fan, if some abnormal thing happens, inspections shall be carried out immediately; if it is small failure, the reason shall be checked out and eliminated, if it is a big failure, the fan shall be stopped and inspection and maintenance shall be made immediately.
8. Except replacing the lubricant after overall, replace the lubricating oil periodically.
The main failure and reason of the fan
1) severe vibration of the fan
① friction between casing (or suction unit)and impeller.
② Foundation is not rigid enough or firm enough.
③ loosing of rivets in impeller or deformation of impeller.
④ Loose match of shaft with impeller disc
⑤ Loose of connecting bolts between casing and support, and between motor and support.
⑥ The installation of inlet and outlet ducts is improper which causes the casing deformation and resonance.
⑦ Rotor unbalance caused by dust, contamination on blades, wear of blades, deformation of impeller and bending of shaft.
2) High rise of bearing temperature
①severe vibration
② lubricant is poor in quality, deteriorated, mixed with dust, sand, contamination and etc, or insufficient in quantity.
③Wornout of rolling bearing
3) Overcurrent and high temperature rise in motor.
① The valves on inlet and outlet pipes are not closed completely when starting-up.
② Input voltage is low or a single phase of power supply is cot out.
③ Influence caused by severe vibration
④ The speed of main shaft is bigger than the rated value.
Purchase information
When ordering, please the fan type, machine number, flow rate, full pressure, the transmission medium, the use of temperature, exit angle and rotation direction,etc..
If the user′s needs are not in conformity with the specifications provided in this manual, please contact the design department of our factory for special design.
Linyi blower works
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