(2) Listen carefully for abnormal noise inside the fan.
(3) Pay close attention to whether the machine has vibration or abnormal noise. If there is oscillation or abnormal noise, stop immediately to check the cause.
(4) Check whether the temperature rise of the bearing is normal, generally not exceeding the indoor temperature of 35℃ ~ 40℃, and the highest temperature of the bearing surface is not greater than 65℃.
(5) Check whether the sealing performance of import and export pipelines and various external applications is normal.
Check whether the electric device cannot start the fan due to dust. Under normal circumstances, there will be a lot of dust in the fuselage after long-term use of centrifugal fans. If the dust is not cleaned in time, the electric device of the fan can not be rented normally, which is likely to corrode the impeller of the fan, resulting in unbalanced bearing and great wear, which will affect the normal efficiency of normal use. It is normal that the fan can't start in this case, which requires users to carry out regular maintenance when using the fan, especially the cleaning of the fan.
Is the inlet closed when the centrifugal fan is started? Is it still open? When the centrifugal fan is started, the inlet is closed, and then it is slowly opened with the increase of air volume until it is normal.
How should the user of centrifugal fan start the motor of centrifugal fan? Now there are more and more users of centrifugal fans. Among these fans, centrifugal fans are the most widely used. They are widely used for dust removal, ventilation and cooling in factories, mines, cooling towers, vehicles, tunnels, ships and buildings. Ventilation and ventilation of boilers and industrial furnaces; Cooling and ventilation in air conditioning equipment and household appliances; Drying and selection of grain; Wind source in wind tunnel and inflation and propulsion of hovercraft. We should pay special attention to the motor part of centrifugal fan, because centrifugal fan is the only power source to start the motor. Therefore, while using the fan, we also need to start the motor of the fan effectively, so as to make every start successful. Today, we will take the centrifugal fan as an example to explain carefully to the users what methods centrifugal fan users usually choose to start the fan. Now we know that the fan depends on the motor as the only power source, and users need to know the power of centrifugal fans in detail in advance. Many devices are actually the same as centrifugal fans, and users need to ensure adequate power supply. Only in this way can the centrifugal fan be started more smoothly. Stable voltage is the key to ensure the power of centrifugal fan. Is voltage instability harmful to centrifugal fans? The danger is certain. The unstable voltage of the centrifugal fan may burn out the motor, which requires our users to measure the voltage of the centrifugal fan as much as possible before starting, and then ensure that the voltage of the centrifugal fan is effective within the rated voltage range. After we have done the preparatory work, we also have a detailed understanding of the two most commonly used startup methods of centrifugal fans. Generally speaking, our most common startup methods are full-pressure startup and decompression startup, so what startup method should users choose to better complete the use of the fan? This also requires users to consider the requirements of mechanical load for starting torque according to the given capacity of the power supply network, and to systematically analyze the characteristics of the motor itself to get the specified starting time. For example, if the power grid has a large capacity, the starting current of the motor will not cause obvious voltage drop to the power grid. In addition, the control lines and equipment of the power grid allow enough starting current to pass in a short time, so the full-voltage starting mode can be adopted. If the torque required when the fan is started is not large, and the capacity of the power grid is not very large compared with that of the motor, we should consider how to reduce the starting current and then step down to start. We should start the centrifugal fan in a scientific way. Only in this way can the centrifugal fan play a better role in use and improve its efficiency. But also is beneficial to prolonging the service life of the centrifugal fan and reducing the use cost of users. This is what we should pay attention to when using.
Problems with centrifugal fans Centrifuges suck air from the atmosphere. The inlet of centrifugal fan is negative pressure and the outlet is positive pressure.
Centrifugal fan oil leakage problem German shepherd brand seal, biting quality does not relax!
XHC-10 17 Black Mud Seal Packing
Scope of application:
Black mud packing is suitable for centrifugal pumps, rotor pumps, reciprocating devices and valves. The packing sealing method with packing as the main body is changed, which is not limited by specifications, that is, it is suitable for all packing sealing devices in factories, valves and pumps in industrial fields such as sewage treatment.
Features:
1. Black mud sealing packing does not require high accuracy of packing box and shaft, and is especially suitable for sealing worn shaft.
2. Black muddy sealing mud is widely used in pumps and valves under severe working conditions such as high temperature.
3. The black mud sealing filler is self-lubricating and has a small friction coefficient, which can reduce the loss of shaft power. It can be repaired online without stopping, and it can achieve "zero leakage", which meets the development requirements of energy saving and environmental protection.
Technical demonstration:
Temperature-40℃-+650℃; Pressure: 25MPa；; Chemical resistance: PH 0- 14.
What should I do if the centrifugal fan trips after a long time of use? Check the line or motor for leakage.
120W centrifugal fan abnormal sound is a universal device.
Whether it is 120 watts or 120 kilowatts.
Cause analysis and countermeasures of fan noise
The abnormal sound of the fan is mainly caused by two aspects:
1, mechanical noise
First, the bearing sound noise
The used lubricant model is incorrect, the daily maintenance cycle is too long, there are foreign objects in the bearing box, and the bearing is damaged.
Response measures:
Use the correct lubricant to remove foreign matter from the bearing housing or replace the bearing.
Reasonable maintenance period: 8 hours for fan, 2 months for lubrication maintenance 1 time; Fan 12 hours, monthly lubrication and maintenance 1 time; The fan runs for 24 hours, and is lubricated and maintained for half a month 1 time.
B, abnormal noise of fan structural parts
Loose anchor bolts, loose gaskets and unstable frame connection will all cause severe vibration. Due to the long-term operation of the fan, the vibration is accompanied by abnormal sound.
For example, the screws of protective net, belt protective cover, rain cover, bearing, motor seat, shock absorber and other parts are loose.
Response measures:
Check the installation of each component, adjust the clearance and reinforce each screw.
C, fan internal impeller abnormal noise.
There are foreign objects in the fan, the impeller rubs against the bell mouth, the impeller rubs against the casing, and the spindle rubs against the sealing device.
Response measures:
Clean up the internal foreign matter, and readjust the gap between the bell mouth and the impeller, and the gap between the spindle and the sealing device.
D, motor, pulley abnormal noise.
Friction between belt and pulley, motor bearing damage.
Response measures:
Check the belt tightness, adjust or replace the belt, confirm that the motor is idling, and replace the motor bearing or motor.
2, fan system noise
1. Abnormal noise caused by fan duct vibration?
This kind of vibration is caused by pressure pulsation and airflow disturbance in the air duct system, causing pipeline shaking and abnormal noise.
Response measures:
Check the direction of air duct pipeline, check the valves of air inlet and air outlet, and keep the pipeline system unobstructed.
B, impeller pneumatic abnormal noise.
When the impeller rotates to cut air, the friction between the impeller and the air will inevitably produce aerodynamic noise.
Response measures:
When the air volume and pressure allow, reduce the fan speed. Add silencing cotton to extend the air outlet pipeline or air outlet pipeline. If conditions permit, the fan field can be made into a fan room.
C, fan surge, resulting in bursts of aerodynamic noise.
When the fan starts according to the design parameters, the efficiency curve of the selected fan is close to the surge zone. When the fan starts running, the system is normal. After a period of execution, the change of air volume and pressure pipe resistance in the system makes the execution of the fan slowly approach the surge zone. Fan surge is formed, resulting in abnormal noise.
Response measures:
Adjust the set value of gas flow until the vibration drops to an acceptable level. Adjust the speed of the fan, and then change the air volume and pressure to make the execution curve of the fan break away from the surge zone.
The above are the basic reasons and solutions of abnormal noise of the fan.
I hope to solve the problem perfectly.
Fan abnormal sound has nothing to do with fan wattage, but with the fan itself or the system.
The specific reason needs to correctly understand and judge the problem from the use of the fan on site, and then solve the problem of abnormal sound of the fan.
Restore normal production and living needs.
When the large centrifugal fan is started, can the inlet valve be closed and the outlet valve be opened? Of course, there are many ways to realize it.
You can control the on-off of the inlet solenoid valve and the outlet solenoid valve through the electronic system. Check valves can also be arranged at the inlet and outlet without a circuit control system.
If you are not clear, you can contact me.
KLF precision fluid company
I only know the water pump and fan, and I don't know if my answer is what you want! Adjust the outlet valve. If the flowmeter or pressure gauge is installed at the outlet of the pump, the pump should run at the rated point listed in the performance index table by adjusting the opening of the outlet valve. If the user installs a flowmeter or pressure gauge at the outlet of the pump, the motor current of the pump should be measured by adjusting the opening of the outlet valve to make the motor run within the rated current, otherwise the load of the pump will be carried out (that is, the motor will be burned out). Adjusting the opening of the outlet valve is related to the working condition of the pipeline.
How to start the centrifugal fan at power frequency and how to operate and debug it?
The fan is allowed to start at full pressure or reduced pressure, but it should be noted that the current at full pressure is 5~7 times of the rated current, and the reduced pressure starting torque is proportional to the square of the voltage. When the power grid capacity is insufficient, decompression starting should be adopted. (When the power is greater than 1 1KW, step-down startup should be adopted).
There are at least two people during the trial operation. One person controls the power supply, and the other person observes the operation of the fan. If any abnormal phenomenon is found, stop the machine immediately for inspection. First, check whether the rotation direction is correct; During the operation of the fan, check the running power of each phase.
Whether the current is balanced and exceeds the rated current; If there is any abnormality, the inspection shall be stopped. After running for five minutes, stop the machine to check whether the roof ventilator is abnormal, and start the machine again after confirming that there is no abnormality.
When testing the two-speed fan, start the low speed first and check whether the rotation direction is correct; When starting the high speed, the fan must be stopped and then restarted to prevent the high speed from reversing, resulting in switch tripping and motor damage.
When the fan reaches normal speed, check whether the input power of each phase of the fan is normal, and the execution current of the fan cannot exceed its rated current. If the execution current exceeds its rated current, check whether the voltage supplied to the fan is normal.
For centrifugal fans and fan housings, the required motor power refers to the power that is not needed when the air outlet is fully open under the working conditions to be determined, plus mechanical loss and due reserves, such as the fan outlet is not connected to the pipeline or added.
If the motor idles due to external resistance, there is a danger of burning. For safety reasons, a valve should be added to the air outlet or inlet pipeline of the fan, which should be closed when the fan is started and slowly opened after operation to achieve the following working conditions.
Check and pay attention to whether the fan current exceeds the specified value.