Fan selection and troubleshooting
The air volume adjustment range of Roots blower is 30%-110%, the air volume adjustment range of gear-speed single-stage high-speed centrifugal blower is 55%-100%, the adjustment range of magnetic suspension and air suspension blower can reach 45%-100%, and the adjustment range of multi-stage centrifugal blower is 60%-100%.
In terms of efficiency, single-stage high-speed centrifugal blower (75%-80%) > multi-stage centrifugal blower (70%-80%) > Roots blower (<70%). Rotation, magnetic suspension, air suspension
1. Roots blower VS rotary blower
1. Roots blower
1 ) Features
1.1 Due to the adoption of three-blade rotor structure and reasonable structure of air inlet and outlet in the shell, the fan has small vibration and low noise.
1.2 The impeller and shaft are an integral structure and the impeller is wear-free, the fan performance remains unchanged and can operate continuously for a long time.
1.3 The fan has large volume utilization, high volume efficiency, compact structure and flexible installation methods.
2. Rotary blower
1 ) Features
● Small size, large air volume, low noise and low energy consumption.
● Smooth operation and easy installation.
● Resistant to load changes, with stable air volume (for example, if the pressure in a sewage treatment aeration tank changes, the load changes, but the air volume changes very little with the pressure change).
● Equipped with an air chamber for smooth air dispersion (all models are equipped with an air chamber to prevent air pulsation and ensure smooth air dispersion).
● Excellent materials, ingenious structure and stable performance (the blower is made of all high-quality materials, with exquisite structure, strong and durable, stable performance, and few failures during long-term use).
● Simple maintenance, few failures and long life (low speed, less wear and long life).
When selecting equipment, for occasions with low air volume and pressure but high noise control requirements, rotary fans are selected. Rotary
fans are variable volume compression fans used in small-scale sewage treatment projects. They are small air volume and medium pressure fans with load resistance, low speed, low noise, stable air volume and low energy consumption.
When the advantages are not obvious, you can make a choice after comparing it with the Roots blower.
For occasions with small air volume (less than 100m3 /min) but high pressure requirements, Roots blower can be selected, and Roots blower is suitable for those below 90kW.
Roots blower is a positive displacement blower, which belongs to a constant volume blower. When the pipe network resistance changes, the flow rate changes slightly, and it belongs to a constant flow high pressure blower. The air volume is less affected by the wind pressure, and the wind pressure changes with the change of the pipe network resistance. It is suitable for use in environments with changing water levels, such as SBR process.
The air volume and speed of Roots blower are proportional. When selecting a model, you need to choose a model with lower speed and lower noise under the same air volume and air pressure. Do not choose a model with the highest speed but the air volume and air pressure can meet the requirements. In this case, it is advisable to select a larger model.
2. Magnetic suspension blower VS air suspension blower
1. Magnetic levitation blower
1 ) Features
Energy-saving advantage : Compared with Roots blowers, the efficiency of magnetic levitation blowers is increased by 30~40%. Taking a 160kW magnetic levitation blower as an example, each magnetic levitation blower can save more than 500,000 kWh of electricity and more than 300,000 yuan in electricity bills each year.
Environmental advantages : Magnetic suspension blowers do not require lubrication, and the air they deliver is clean and pollution-free. Magnetic suspension bearings are completely frictionless, and the blower operates with low noise. Based on a 160kW magnetic suspension blower, each blower can reduce carbon dioxide emissions by about 500 tons per year.
Cutting-edge technology : Using advanced control systems, multiple control modes can be selected, the operation of the turntable can be monitored and remotely controlled, without the need for on-site personnel. A fully enclosed water cooling and air cooling system is used to dissipate heat from the motor, ensuring that the fan is in a stable and efficient operating state and that the equipment has a long service life.
Low operating costs : The magnetic bearing is completely frictionless, reducing the chance of product damage, and the service life of the blower can reach more than 20 years. The magnetic levitation blower is easy to maintain, only requiring regular replacement of filters. The magnetic levitation blower does not require a lubrication system, saving costs such as lubricating oil and cleaning.
2. Air suspension blower
1 ) Features
2.1 Energy saving and high efficiency
The air suspension centrifugal blower uses air bearings , direct-connection technology, high-efficiency impellers, permanent magnet brushless DC motors, and no additional friction. The fan automatically adjusts the motor power consumption according to the output (the air volume can be adjusted within the range of 40-100%) to maintain high efficiency of the equipment.
2.2 No vibration, low noise
Adopting air bearing and direct connection technology, no vibration is generated and the fan does not need to be equipped with sound insulation devices; the equipment is light in weight, does not require a special foundation, and the installation layout is simple and flexible.
2.3 No lubricating oil
The fan adopts air bearing technology, the system does not need lubricating oil system, and provides clean air to special industries such as electronics, medicine, food, etc. The use temperature of air bearing reaches 600 degrees, and all the disadvantages of oil bearing system have been successfully solved.
2.4 No maintenance
There are no gearboxes and oily bearings required by traditional fans. A series of high-tech impellers and motors are directly connected without couplings, and an intelligent control system is used. Key components are made of AL7075 (aviation aluminum). These technologies ensure that the equipment is maintenance-free, reduce users' maintenance costs, and improve the stability of the air supply system operation.
2.5 Convenient operation control
The fan speed, pressure, temperature, flow rate, etc. can be self-checked on a personal computer and operated at constant pressure, load/no-load operation, overload control, and unmanned operation can be achieved through anti-surge control. The fan adjusts the flow rate by adjusting the speed of the impeller. The flow rate can be easily adjusted by adjusting the speed according to the temperature and pressure changes of the inhaled air. The flow rate can be adjusted automatically and manually.
2.6 Small equipment installation space
air suspension centrifugal blower equipment is light in weight, small in size, and easy to install, which can greatly save the user's investment in building and auxiliary electrical control systems .
3. Installation and debugging
1. Roots blower
2 ) Installation and debugging
2.1 Mistakenly install the fan in a place where people frequently go in and out to prevent injuries and burns.
2.2 Mistakenly install the fan in a place where flammable, explosive and corrosive gases are likely to be produced to prevent accidents such as fire and poisoning.
2.3 The fan can be used for a long time at an ambient temperature not exceeding 40℃. When the ambient temperature exceeds 40℃, exhaust fans and other cooling measures should be installed to increase the service life of the fan.
2.4 When conveying air, biogas, natural gas and other media, the dust content should generally not exceed 100mg/m3.
2.5 There should be no scaling, rust or peeling inside the blower body.
2.6 Pay attention to whether the lubrication and heat dissipation are normal, pay attention to the quality of the lubricating oil, often listen to whether there is any noise when the blower is running, pay attention to whether the unit is running under conditions that do not meet the regulations, and pay attention to adding butter regularly.
2.7 To avoid blower overload, pay attention to the increasing trend of intake and exhaust pressure, bearing temperature and motor current to determine whether the machine is operating normally.
2. Rotary blower
2 ) Installation and debugging
2.1 The fan room should have ventilation holes and be equipped with ventilation fans. The ventilation holes should be located at the top and bottom to facilitate air convection to prevent the room temperature from being too high and affecting the normal operation of the rotary blower.
2.2 It is best to install sound-absorbing materials around the inner walls of the machine room to reduce noise.
2.3 The diameter of the air distribution pipe should not be smaller than the exhaust diameter of the rotary blower, and attention should be paid to the cleanliness of the pipe. The air supply pipe should be installed above the water surface to prevent water from entering the pipe and causing excessive pressure during starting.
2.4 Be careful not to screw the check valve down when connecting the pipe (the raised part of the check valve should face upwards).
2.5 The electrical wires must be connected correctly and the motor rotation direction must be consistent with the rotary blower rotation direction mark.
2.6 When two rotary blowers are used for alternating operation, frequent replacement and starting of the blowers in a short period of time should be avoided. The continuous operation time of a rotary blower shall not be less than 12 hours.
3. Magnetic levitation blower
2) Installation and debugging
2.1 Pipeline installation : Confirm the process air inlet direction of the fan and install the filter cotton, but no pipeline connection is required.
The outlet duct needs to be aligned with the outlet flange of the fan and requires an independent support frame.
Avoid stress on the fan caused by the pipeline. A flexible expansion joint (soft connection), a check valve, and a pipe silencer should be installed between the flange of the fan outlet and the user's outlet pipe. The inner wall of the pipe should be clean and smooth. A rough inner wall of the pipe will increase the noise of the airflow.
The air outlet of the vent valve should be connected with a pipe and face a safe area to avoid accidental injury. The cooling exhaust port of the fan should face a safe area to avoid burns.
2.2 Electrical installation : The fan power supply is three-phase five-wire (TN-S) 380V/50HZ, the input voltage deviation is less than 10%, and the voltage term difference is less than 2%.
Cables are protected by pipelines or bridges, and the neutral wire and ground wire cannot be mixed.
The cable appearance should be free of wear and tear, and the cable phase-to-phase insulation resistance and grounding resistance should meet the standards.
The specification of the circuit breaker on the power supply side shall not be smaller than the configuration of the internal circuit breaker of the fan.
The cable joints are standardized, with the three-phase lines marked in yellow, green and red respectively, and the ground wire marked with a yellow and green alternating heat pipe.
The ground wire is connected to the grounding copper busbar, and the grounding resistance should be less than 4 ohms. To reduce electromagnetic interference, it is recommended to ground nearby.
After power is turned on, the temperature of the power cable and copper pipe joint should be less than 50℃.
4. Air suspension blower
2. Installation and debugging
Do not open the box before installation: Do not open any part of the equipment box, such as the main box or the electric control box, before the equipment is installed, so as to prevent foreign objects from falling into the machine during the installation process and affecting the use of the equipment.
The installation location needs good air circulation: You should choose an appropriate location to install the blower to ensure that it can operate normally and provide the required blowing effect. Considering the ventilation and heat dissipation requirements, it is best to choose an area with good air circulation and ensure that there are no obstacles around the blower.
The installation foundation needs to be firm and stable: Make sure the installation foundation is firm and stable and can withstand the weight and vibration of the blower. According to the size and weight of the blower, select the appropriate foundation material and structure.
Ensure a stable power supply: Ensure that there is a stable and reliable power supply that meets the electrical requirements of the blower. Check whether the power supply voltage and frequency match the rated parameters of the blower, and ensure that the power supply line meets safety standards.
Install a proper drainage system: If your blower requires wastewater or cooling water to be discharged, you need to ensure that a proper drainage system is installed. Consider the location and slope of the drain pipe to ensure that the wastewater can be effectively discharged.
Appropriate connecting pipes need to be installed: according to the inlet and outlet sizes and connection requirements of the blower, install appropriate pipes and joints. Make sure the pipe connections are firm and leak-free, and install valves and other control equipment as needed.
4. Common faults and solutions
1. Rotary blower
3) Common faults and solutions
3.1 Insufficient air volume of rotary fan
You can check whether the fan belt is slipping or rotating; whether the gap of the rotary fan is increasing; whether the fan inlet resistance is increasing.
3.2 Rotary fan motor overload
Check whether the rotary blower filter is clogged or overloaded; whether the actual operating pressure of the blower exceeds the rated working pressure marked on the factory nameplate; check whether the friction between the impeller and the cylinder is abnormal;
3.3 Overheating of rotary fan
Check whether the rotary fan oil box is poorly cooled; whether the friction between the fan rotor and the cylinder wall is abnormal; whether the boost pressure is too high, and whether the lubricating oil is added excessively;
3.4 Abnormal sound from rotary fan
Check whether the adjustable gear and rotor are out of adjustment, check whether the bearing is seriously worn, and whether the gear is damaged . 3.5 The rotary fan cannot start normally
Check whether the air inlet and outlet are blocked or the valve is not open, or whether there is any electrical problem;
3.6 Rotary fan has large vibration
Check whether the rotary fan is basically stable, whether the wheels are aligned, and whether the bearings are abnormally worn.
2. Magnetic levitation blower
3) Common faults and solutions
3.1 Overload protection problem
During the operation of the magnetic suspension blower, due to excessive or uneven load, the overload protection may be triggered, causing the blower to shut down. At this time, an alarm reset or manual reset is required. If normal operation cannot be restored after multiple resets, the fan bypass capacitor should be checked for damage and replaced.
3.2 Temperature control protection failure
When the motor temperature of the magnetic levitation blower is too high, the temperature control protection will be automatically triggered and the operation will stop. This is to protect the equipment from excessive damage. If the temperature control protection fails, the motor will overheat. It is necessary to check whether the temperature control switch is normal and whether there is any malicious operation that causes the temperature control to fail.
3.3 Bearing damage problem
The bearing of the magnetic levitation blower is its core component. If the bearing is damaged, the blower will not work properly. In actual use, common bearing failures are wear, breakage, and oxidation, which need to be replaced in time. When replacing the bearing, it is necessary to follow the steps given by the manufacturer to avoid improper installation and other human errors that may cause unstable equipment operation.
3.4 Electromagnetic interference problem
During the transportation or installation of the magnetic levitation blower, it may be affected by electromagnetic interference, which may cause abnormal operation or failure of the equipment. At this time, you can take the approach of increasing shielding to reduce the impact of external electromagnetic interference. During the use of the equipment, you also need to regularly check whether each electrical connector is tightened and whether the power supply voltage is stable to avoid electrical failure of the equipment.
3. Air suspension blower
3) Common faults and solutions
3.1 Excessive rotor friction: The possible cause is bearing failure or poor lubrication. Check the bearings and repair or replace them in time.
3.2 Unstable wind speed: This may be caused by a fault in the electrical system. Check the electrical system and repair the fault.
3.3 If the inverter communication is abnormal, the inverter is abnormal or stops urgently, or the sensor and data communication are abnormal, you need to contact the manufacturer;
3.4 If the outlet pressure exceeds the limit value, confirm whether the load (pipeline integrity, water level, etc.) has increased significantly;
3.5 If the filter pressure difference limit is exceeded, clean or replace the suction filter;
3.6 If the motor temperature exceeds the limit value, take cooling measures such as indoor watering and forced ventilation;
3.7 If surge occurs, confirm the performance curve. If it is running on the SURGE line, increase SV;
3.8 Warning of maximum filtration pressure difference of 95%, clean or replace the suction filter;
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