How to maintain high temperature smoke exhaust fan and prolong service life?

High temperature smoke exhaust fans are widely used in ventilation system. The below are several maintenance methods.

high temperature smoke exhaust fan

1. Adding lubricating grease regularly, from zerk fitting by fuel truck nozzle. You can open the oil discharge outlet under motor cover to discharge waste oil. 
If there is oil starvation in the bearings, please check out the reason firstly, and add oil at any time. 

2. High temperature smoke exhaust fan starts to run at least once a month, so as to have good motor bearing lubrication. 

3. It is better to check attachment bolt regularly. Once the loose, spring washers have to be changed and fasten again. 

high temperature smoke exhaust fan

4. Checking fan running situation at fixed period, if there are any friction, loose and strenuous vibration,then check out the problems carefully and remove the obstacle. 

5. Inspecting the bearing of the high temperature smoke exhaust fan. Toggle the impeller, listen whether there are any sounds of bearing's looseness and friction, then  remove the trouble. 

Performance Parameters of Centrifugal Fan

Specification and Parameters of Centrifugal Fan, the main parameters are airflow, air pressure, power, efficiency, speed and so on. 

xianrun blower centrifugal fan

1. Air pressure H, which is the energy of per unit volume air from blower. In general,blower air pressure is the difference of full pressure of air outlet and air inlet. 
The total pressure equals to the sum of static pressure and dynamic pressure, and the unit is Pa. 

2. Air flow Q, the air volume per unit time from blower, the unit is m³/s or m³/h. 

3. Power N, during air ventilation, air obtain energy from blower, and blower consumes motor power. The energy that blower deliver to air in unit time is called effective power, the power unit is W. 
 N=HQ, in this formula, N is the effective power of fan (W), Q is the air volume (m³/s), H is the full pressure(Pa)

high efficiency xianrun blower

4.Efficiency E, actually, there is energy loss in blower working, so blower input power is bigger than N. 
Nsh=N/E=HQ/E    Nsh is shaft power (W), E is blower efficiency. In general, the efficiency of backward curved blower is 0.8~0.9; forward curved blower efficiency is 0.6~0.65 

The Structure of Centrifugal Blower

1. Fan Impeller 

The impeller is composed by blades, front plate, rear plate, and the wheel hub.The blades are welded on two sides plate; rear plate is riveted with wheel hub by rivet; 
the whole impeller is fixed on the crankshaft by wheel hub.

impeller fan

Some high pressure fan impeller is casted entirely.For now, the direction of fan impeller front plate tends to be tapered or conical curved, which is consistent with the direction of air flow, to help reduce obstruction and improve fan efficiency.

Fan impeller is the most important components in blower. In particular, the blade form in impeller has the biggest effect on the blower performance.

2. Casing 

The blower performance and efficiency mainly depend on fan impeller, but the shape and size of casing, the shape of the air inlet, etc., also have important influence.

The role of the casing is to collect air from the impeller, and make the air flow to air outlet, at the same time, to make the air dynamic pressure from the impeller convert to static pressure.

different direction of outlet

Air flow has the least resistance in spiral shape casing. The cross section of spiral casing expands gradually along the impeller rotation direction, and reach the maximum in air oulet. 

In order to meet working place requirements, one model blower can have different outlet shapes, with the different direction of rotation and angle. 

For example, from the motor side, if the fan impeller rotates clockwise,this fan is right-turn blower; on the contrary, this fan is left-turn blower. Right is the basic rotation direction. 

3. Supporting and Drive Modes

Generally, the supporting is made from cast iron or carbon steel. 

different drive modes of centrifugal fan

The driving modes include A, B, C, D, E, F. 

A--Cantilever supporting, and motor drive directly

B--Cantilever supporting, and belt pully drive

C--Cantilever supporting, and belt drive

D--Cantilever supporting, and coupling drive

E--Double supporting, and belt drive

F--Double supporting, and coupling drive

The Working Principle of Centrifugal Fan

Centrifugal fan is mainly composed of impeller, casing, wheel hub,shaft, air inlet and air outlet, and bearing pedestal, supporting, and belt pulley (or coupling), and other components. 

Fan Impeller Rotation

Its axis is connected to the motor shaft through the coupling or pulley and belts.When motor drives the impeller to rotate, the air also along with the impeller rotating,under the action of inertial, the air is thrown around, and pooled into the spiral casing. In the process of air flow to the air outlet in casing,the cross section expands, wind speed slows down, most dynamic pressure changes into static pressure, finally, the air is exhausted from air outlet in certain pressure. 

When the air is expelled by the impeller, there are some certain vacuum in impeller center, under the action of atmospheric pressure, the air outside of air inlet are induced into impeller. The impeller rotates constantly, so the air is induced and exhausted continually. 

Obviously, the blower fan pass the energy to air by impeller rotation so as to achieve the aim of the air ventilation. 

all xianrun blower

The air intake (air inlet) of centrifugal fan pressure is a negative pressure, and exhaust port (air outlet) pressure is positive pressure. So it can force air to boilers, or kilns, 
they can also exhaust air from the furnace. 

The Definition and Classification of Fan

The fan definition

The machines, which are used to suck gas, exhaust air, and compress gas, all can be called fan or blower. 


The fan classification 
1. According to different working principle, there are two categories, impeller type fan and displacement blower. 
Impeller type fan includes centrifugal fan and axial flow fan. The displacement blower includes piston fan and rotary fan. 

low pressure fan, medium pressure fan, high pressure fan

2. According to different discharge pressure, there are 4 kinds fan. 
A: Ventilation fan, discharge pressure is below 14.7 Kpa. 
B: Air blower, discharge pressure is between from 14,7~ 300 Kpa. 
C. Gas compressor, discharge pressure is over 300 Kpa.
D. Vacuum pump, this fan can produce vacuum over 50 Kpa. This machine is used to improve, produce, and keep the vacuum of some enclosure space. 

3. According to air pressure, the impeller type fan can be divided into low pressure fan (air pressure below 1 Kpa); medium pressure fan (air pressure between 1~3Kpa), high pressure blower (air pressure 3~14.7 Kpa).

low pressure impeller, medium pressure impeller, high pressure impeller

The Features of Industrial Fans and Blowers in Power Plant

Centrifugal Fan and Axial Flow Fan in Boilers of Steam Power Plant

xianrun industrial fans and blowers

Situation	Application	Fan Type	Medium	Features
Boilers of Steam Power Plant	ID Fan  (induced  draft fan)	Centrifugal fan, axial flow fan	Boiler smoke	When burning heavy oil, pay attention to the corrosion by sulfur composition in the exhausting; when burning coal, pay attention to the wear caused by dust. It needs to equip dust-extraction device in front of ID fan, and high efficiency motor.
	FD Fan  (forced  draft fan)	Centrifugal fan, axial flow fan	Air	As for the axial flow fan, utility-type unit can use adjustable blade axial flow fan. During the forced draft, because of high pressure, high nose, it is better to use silencer device.
	Coal dust exhausting	Centrifugal fan	Coal dust	According to the purpose, the coal dust exhausting fan can be divided into two kinds. One, pulverized coal storage bin type exhausting fan. It blows pulverized coal from side into furnace. The coal dust do not go through the fan, so the fan pressure needs to be much high.
	Coal dust exhausting	Centrifugal fan	Coal dust	The other is straight type dust blower. It sends the coal dust into furnace directly. Because of the impeller and casing wear, the fan needs to processed with wear-resistant treatment.
	Gas recirculating fan	Centrifugal fan	Boiler fume	This model fan exhausts high temperature boiler fume, so the material and structure should be heat resistant.
	Smoke extraction fan for desulphurization	Centrifugal fan	Boiler fume	This fan is installed in front of desulphurization equipment.
	Atomic energy furnaces  ventilation fan	Centrifugal fan, axial flow fan	Air	For the safety of atomic energy furnaces, the fan should have high quality and reliable.

wear-resistant treatment

The Features of Industrial Fans And Blowers in Iron and Steel Smelting

The Features of Industrial Fans And Blowers in Different Situations

Part One---Iron and Steel Smelting

high pressure blower

Situation	Iron and Steel Smelting
Application	iron-melting furnace ventilation fan	sintering furnace cooling fan
Fan Type	centrifugal fan	centrifugal fan, axial flow fan
Medium	Air	Air
Features	Under high pressure, low airflow, this model fan is required to have the features of high efficiency, low noise, flat performance curve, wide efficient range. It needs to have high strength, because of high pressure and high speed.	High efficiency axial flow fan is better for ventilation, but the noise is big. For induced draft fan, because of serious wear, it is better to use centrifugal fan with wear-resistance structure.

axial flow fan

Xianrun fan design,lxrfan.com.xrblower.com

Xianrun Blower New Product----Sprayers and Dusting Machine

Sprayers and Dusting Machine

With the development of coal mines, steel mills, raw material yard, ports and other industries,mechanization levels increase significantly. 
But there are large amount of dust in the mining transport, storage and other links,these dust will be a serious threat to production of industrial and mining enterprises and workers' health. 

Xianrun Blower Factory provides series of sprayers and dusting machine (underground explosion-proof,normal), which can effectively control dust,reduce dust concentration, improve the working environment to prevent industrial accidents.

Sprayers and Dedusting Fan Machine

Performance Features:

· The product has strong wind, high and far range, sound penetrability,  small fog droplet,      and can achieve precision spray, quickly sink down mine yard dust; 

· This product also have the features of high efficiency, high speed, its coverage area is much greater than other spray dust suppression equipment;

· Domestic high-quality diesel generator sets, this machine is stable, reliable, and have high security;

· Spraying angle and the horizontal rotation angle can be controlled and adjusted easily; 

Sprayers and Dedusting Fan Machine

· This machine can realize spraying while driving,also allows remote operation in cab;

· 1-10 tons water tank of this machine can be customized, solving problem of adding water;

· This sprayers and dusting machine can use 380V, 3 phases, as well as assorted electric generator;

· The product can be fixed mounted on the platform, and can also be installed in all kinds of light truck trucks, tractors.

Centrifugal Fans---Forward Fan, Radial Fan, Backward Fan

Centrifugal Fans---Forward Fan, Radial Fan, Backward Fan

Centrifugal Fans---Forward Fan, Radial Fan, Backward Fan

The impeller is an important part of centrifugal fan,and its geometric shape, size, number of blades, and the manufacturing accuracy have great influence on centrifugal fan performance. Impeller static balance or balancing correction can ensure smooth rotation of centrifugal fan.

According to different direction of the blade outlet, the impellers are divided into forward, radial and backward impeller. 

Forward impeller blades incline to the impeller rotation direction; radial impeller blades are in the radial direction; backward impeller blades incline to the reverse impeller rotation direction. 

As for the same air flow and speed, forward impeller generates the maximum pressure,required the minimum impeller diameter, with low efficiency. On the contrary, backward impeller generates the minimum pressure,required the maximum impeller diameter, with high efficiency. The performance of radial fan are in between.  

forward curved impeller,radial impeller, backward curved impeller 

Straight blades is the most simple,while in order to have a suitable velocity distribution on blade surface, the centrifugal fan is always equipped with curved blades impeller. 
The front disc on fan impeller increases the impeller strength and reduces air leakage between the blades and casing. The impeller and frond disc are coupled by welding or riveting. Welding impellers have light weight, smooth flow channel.

During the centrifugal fan working, the motor drives the impeller rotate inside the volute casing, the air is sucked through impeller center by air inlet. 

Since the dynamic action of the blade on the gas, the air pressure and speed are improved,
Then under the centrifugal force, the air goes along the blade and is discharged from the air outlet. In general, centrifugal fan has one side air inlet with single suction impeller;
If the air flow is very large, centrifugal fan can have two side air inlet with double suction impeller, two back to back impellers. 

single suction and double suction blower

Blade wheel is balancing, Xianrun blower ,xrblower.com,lxrfan.com, xxblo...

The Development History of Centrifugal Blower and Axial Flow Fan

The Development History of Centrifugal Blower and Axial Flow Fan 

As early as the Shang dynasty (c.1600-c.1046 B.C.) and Western Zhou Dynasty (c11th century-771 B.C.), Chinese people had invented air bellows with forced air features, for smeltery and foundry. 

 air bellows

Firstly, Chinese people used cow or horse leather to make leather bag. They connected duct or pipe to the leather bag,and forcing air by breathing the bag. Then, in the Warring States Times, these leather bags were installed in parallel or in series to reach better ventilation effect. 

Propeller windmill also was created and used in ancient China, and it was the ancestor of axial flow fan.
In southern China, people invented grain milling wind car, and they are still in using today. They can be said the ancestor of modern centrifugal blower fan and compressor.

grain milling wind car

1862, Guido Bell from England invented centrifugal blower. The impeller, casing were concentric circular,the casing was made from brick, while wooden impeller was backward straight blade. The efficiency just reached 40%, and they were mainly applied in mine ventilation at that time. 

1880,for mine ventilation, some engineers designed centrifugal blower fan with volute casing and backward curved blade. The centrifugal fan construction was improved step by step. 

Chinese ancient centrifugal fan

1892, French invented crossflow fan. 

1898, Irish invented forward West Luo Ke type centrifugal fan, then it was widely used by other country. 

In the 19th century, axial flow fan was used as forced draft fan for metallurgical industry. But the pressure was just 100~300pa, and the efficiency only reached 15~25%. The technology did not get fast development until after 1940s. 

1935, German used axial flow fan to force air and induce air for boilers firstly.

1948, Danes created adjustable blade axial flow fan during the operation. Then all kinds axial flow fan had great development. 

old centrifugal fan

Part Three---The features of axial flow fan

Centrifugal Fan VS Axial Flow Fan

Part Three
The features of axial flow fan

centrifugal fan vs axial flow fan

1. The axial flow fan is suitable for low pressure and large airflow. The fan connect with motor shaft directly, and it has high operating speed. 

2. Light structure, and high work efficiency. 

3.Because the airflow direction parallels to the axle of axial flow fan, it can be easily connected to the pipe or duct. 

4.Axial flow fan can adjust air flow or increase efficiency by changing blade angle and length. 

axial flow fan

5.Axial flow fan can supply air reversely. 

6.Compared with centrifugal fan, the price is cheaper. 

axial flow fan used in cement kiln

Part Two ---The features of centrifugal fan

Centrifugal Fan VS Axial Flow Fan

centrifugal fan vs axial flow fan

Part Two
The features of centrifugal fan

centrifugal fan

1. Structure: 
Compact structure, beautiful appearance, good stability, what's more easy installation and convenient maintenance.

2. Stable operation: 
Optimal design of the impeller makes the axial force to minimum, and the efficiency is high.After static and dynamic balance correction, the impeller make the machine running smoothly, and in the absence of any vibration damping device case, bearing amplitude is less than 0.04mm.

3. Low noise: 
During the centrifugal blower running,there is no mechanical friction. Centrifugal fan adopting reasonable blade-shaped line to make the voice drop to a minimum. Centrifugal fan noise 
belongs to high-frequency noise, as long as there are obstacles, they can deaden the noise. 

4. Oil-free machinery: 
Centrifugal blower bearings use grease lubrication, and bearing life is more than three years. Centrifugal fan does not produce oil gas during the operation.

5.Impeller: 
Impeller adopts special compound linear, reduces the internal leakage, increases the volumetric efficiency.

centrifugal fan impeller

6.Air adjusting: 
Adjusting door is easy to operate to control airflow and air pressure. 

7.Motor
According the differenct grid of customers, the blower can be equipped with variable frequency motor, high voltage motor, explosion-proof motor, or different voltage motor. 

8.Cooling
Bearing housing have two cooling methods, water-cooling, oil-cooling, all these prolong the service life of bearing. 

9.Driving modes
There are direct driving, belt driving, coupling driving. According to the equipments and performance, the blowers can choose suitable driving mothod. 

high pressure blower