Place of Origin: | Hangzhou,China |
Brand Name: | Tailian |
Certification: | ISO,CE |
Model Number: | Roots oilfree blower |
Minimum Order Quantity: | 1 pc |
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Price: | negotiation |
Packaging Details: | wooden case |
Delivery Time: | a month after payment |
Payment Terms: | L/C, T/T |
Supply Ability: | 100 pcs per month |
Model: | JGR150VH-N | Power: | 22kw |
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Drive Mode: | Belt Drive | Speed: | 1100r/min |
Flow: | 15m3/min | Booster: | -50kpa |
Condition: | New | Origin Of Place: | Hangzhou,China |
JGR150VH - N Oxygen Plant Spare Parts 15m3 / Min Roots Oilfree Blower
1.description
A centrifugal fan is a mechanical device for moving air or other gases. The terms "blower" and "squirrel cage fan", (because it looks like a hamster wheel), are frequently used as synonyms. These fans increase the speed and volume of an air stream with the rotating impellers.
Centrifugal fans use the kinetic energy of the impellers to increase the volume of the air stream, which in turn moves them against the resistance caused by ducts, dampers and other components. Centrifugal fans displace air radially, changing the direction (typically by 90°) of the airflow. They are sturdy, quiet, reliable, and capable of operating over a wide range of conditions.Centrifugal fans are constant displacement devices or constant volume devices, meaning that, at a constant fan speed, a centrifugal fan moves a relatively constant volume of air rather than a constant mass. This means that the air velocity in a system is fixed even though the mass flow rate through the fan is not.Centrifugal fans are not positive displacement devices and centrifugal fans have certain advantages and disadvantages when contrasted with positive-displacement blowers: centrifugal fans are more efficient, whereas positive-displacement blowers may have a lower capital cost.The centrifugal fan is one of the most widely used fans. Centrifugal fans are by far the most prevalent type of fan used in the HVAC industry today. They are often cheaper than axial fans and simpler in construction. They are used in transporting gas or materials and in ventilation systems for buildings and vehicles. They are also well-suited for industrial processes and air pollution control systems.
The centrifugal fan has a drum shape composed of a number of fan blades mounted around a hub. As shown in the animated figure, the hub turns on a driveshaft mounted in bearings in the fan housing. The gas enters from the side of the fan wheel, turns 90 degrees and accelerates due to centrifugal force as it flows over the fan blades and exits the fan housing.
2.constructure
Main parts of a centrifugal fan are :
Other components used may include bearings, couplings, impeller locking device, fan discharge casing, shaft seal plates etc.
The fan drive determines the speed of the fan wheel (impeller) and the extent to which this speed can be varied. There are three basic types of fan drives.
The fan wheel can be linked directly to the shaft of an electric motor. This means that the fan wheel speed is identical to the motor's rotational speed. With this type of fan drive mechanism, the fan speed cannot be varied unless the motor speed is adjustable. Air conditioning automatically provides faster speed because colder air is denser.
Some electronics manufacturers have made centrifugal fans with external rotor motors (the stator is inside the rotor), and the rotor is directly mounted on the fan wheel (impeller).
A set of sheaves is mounted on the motor shaft and the fan wheel shaft, and a belt transmits the mechanical energy from the motor to the fan.
The fan wheel speed depends upon the ratio of the diameter of the motor sheave to the diameter of the fan wheel sheave and can be obtained from this equation:[10]
{displaystyle rpm_{fan}=rpm_{motor},{bigg (}{frac {,D_{motor}}{D_{fan}}}{bigg )}}
Fan wheel speeds in belt-driven fans are fixed unless the belt(s) slip. Belt slippage can reduce the fan wheel speed by several hundred revolutions per minute (rpm).
Variable drive fans may use hydraulic or magnetic couplings (between the fan wheel shaft and the motor shaft) that allow variable speed. The fan speed controls are often integrated into automated systems to maintain the desired fan wheel speed.
An alternate method of varying the fan speed is to use an electronic variable-speed drive to control the speed of the motor driving the fan. This offers better overall energy efficiency than mechanical couplings, especially at greatly-reduced speeds.
Bearings are an important part of a fan. Sleeve-ring oil bearings are used extensively in fans. Some sleeve-ring bearings may be water-cooled. Water-cooled sleeve bearings are often used when the fan moves hot gases. Heat is conducted through the shaft and into the oil, which must be cooled to prevent overheating the bearing. Lower-speed fans have bearings in hard-to-reach spots, so they use grease-packed bearings.
Many turbo blowers use either an air bearing or a magnetic bearing.
Inlet dampers (inlet vanes) reduce fan energy usage due to their ability to affect the airflow pattern into the fan.
Fan blades
Figure 3: Centrifugal fan blades
The fan wheel consists of a hub with a number of fan blades attached. The fan blades on the hub can be arranged in three different ways: forward-curved, backward-curved or radial.
Forward-curved blades, as in Figure 3(a), curve in the direction of the fan wheel's rotation. These are especially sensitive to particulates and commonly are only specified for clean-air applications such as air conditioning. Forward-curved blades provide a low noise level and relatively small air flow with a high increase in static pressure.
Backward-curved blades, as in Figure 3(b), curve against the direction of the fan wheel's rotation. Smaller blowers may have backward-inclined blades, which are straight, not curved. Larger backward-inclined/-curved blowers have blades whose backward curvatures mimic that of an airfoil cross section, but both designs provide good operating efficiency with relatively economical construction techniques. These types of blowers are designed to handle gas streams with low to moderate particulate loadings[They can be easily fitted with wear protection but certain blade curvatures can be prone to solids build-up.Backward curved wheels are often heavier than corresponding forward-curved equivalents, as they run at higher speeds and require stronger construction.
Backward curved fans can have a high range of specific speeds but are most often used for medium specific speed applications—high pressure, medium flow applications.Backward-curved fans are much more energy efficient than radial blade fans and so, for high power applications may be a suitable alternative to the lower cost radial bladed fan.
condition | new |
color | option |
origin of place | Hangzhou,China |
flow | 15m3/min |
type | roots oilfree blower |
model | JGR150VH-N |
drive mode | belt drive |
power | 22kw |