Boiler Centrifugal Exhaust | Extractor Induction Draft | Draught Flue Dilution Fan Blower Y8-39 Y9-38 Series

Boiler Centrifugal Exhaust | Extractor Induction Draft | Draught Flue Dilution Fan Blower Y8-39 Y9-38 Series

Type Y8−39 and Y9−38 centrifugal induced draught fan for boiler can operate at high efficiency area when industry boiler operate in changing operation condition. The purpose of energy-saving is reached.
Product description

GENERAL
Type Y8−39 and Y9−38 centrifugal induced draught fan for boiler can operate at high efficiency area when industry boiler operate in changing operation condition. The purpose of energy-saving is reached. The fan is joint designed by the fan energy-saving group of Mechanical Building Industry Department and the famous factory of state fan trade. It is highly effective products which mainly recommended by State Economic and Trade Commission and Department of Mechanical Building Industry. It has advantages of highly efficiency, low noise and wide range highly effective area of performance curves.


The fan is suitable for 0.5~35t/h industrial boiler equipped with coal-saving unit(preheater)and smoke prevention and dust control unit. It can be selected by similar inlet condition and performance, but the maximum inlet temperature should not exceed 250℃.
Dust removal equipment that not less than 85% dust removing efficiency must be installed in the front of induced draught fan, in order to reduce the fume content into the fan and minimize dust abrading on fan, and improving the service life of fan.


There are many series of industrial boiler at present. The burning coal in high and low grade is vast difference. The resistance of dust removing unit and coal saving unit is not uniform. There are great different between the flow rate and pressure of induced draught fan. Take into account the economics and suitability of the fan, provide Type Y8−39 and Y9−38 two series of fan for users to select. Connection and installation dimension of two series fan with the same model is the same.


TYPE
The fan is made as a single suction. There are 13 types of fan numbers which are 4, 4.5, 5,  5.6, 6.3, 7.1, 8, 9, 10, 11.2, 12.5, 14 and 16.
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, symbolized with "right", On the contrary, it is called as counter-clock-wise fan if the impeller rotates counter-clockwise, symbolized with "left".
The outlet position of the fan can be expressed from the outlet angle of the casing. It can be made 6 kinds of angles which are 0°, 45°,90°, 135°,180°,225°,from both "Right" and "left".
When the rotation, outlet angle and driving mode of the mentioned fan numbers can not meet you requirement, we have ability to transform or design again for you, until you are satisfied with it.


STRUCTURE
The series fan consists of impeller, casing, inlet, damper and driving unit, etc:
Impeller — vane is made from 16Mn, impeller after shaped is subject to strict static/dynamic balance calibration and overspeed operation experiment, operation is smooth and reliable, with long servive life.

 

Casing — To be welded into a volute with normal steel plate. There is a cleaning dust door on the volute in order to remove dust in blade and casing and ensure the balance and aerodynamic performance of impeller.

Inlet —To be integrated into a convergent streamlined structure and bolted on the suction side of the casing. 


Driving unit — Consists of main shaft, bearing box.The main shaft is made of super steel. The rolling bearings is used. There are two kinds of bearing boxes, integral and split. Integral bearing box is used for №4~6.3 and split bearing box is used for №7.1~16. Water cooling is required on two kinds of bearing boxes. Water consumption is different according to working temperature and ambient temperature, generally take 0.5 m3/h~1m3/h. There are thermometer and oil level indicator on bearing box. 30# mechanical oil is used on bearing box. The oiling quantity is performed according to the marks of oil level. 


Damper — Damper is petal regulating, axially installed in the front of the inlet. The structure of external driving is used, rotating is easy and flexible. Adjusting range is from 90°(full close)to 0°(full open) . The handle position of damper is at the right hand viewing from the inlet side. For "Right"rotating fan, the handle from down to up is from full close to full open direction. For "left"rotating fan, the handle from up to down is from full close to full open direction. In order to make each part of damper normally operate, lubrication must be done well. It is recommended that bentone grease with high temperature(260℃)is used and ensure the fan could not be out of function during operation with high temperature.


PERFORMANCE AND SELECTION
Performance parameter in performance table of the fan is converted with non-dimensional performance table"table 1" "table 2".
The converting result is correct when Re≥5×106, and when Re≤5×106, the relative correction is performed on each fan №. according to test results. Its value takes performance table as a standard.

11.jpg


Where:
Re —  Reynolds number
D—  Diameter of outside end of impeller blade(m)
U—  Line speed of outside end of impeller blade(m/s)
μ — Coefficient of kinematic viscosity (0.15×10-4) m2/s


The dimensional performance curve is converted with non-dimensional performance curve. The converting formula is as follows:

22.jpg


On-dimensional performance table of type Y8-39                                                                                               table 1

Code

1

2

3

4

5

6

7

111.jpg

0.118

0.140

0.162

0.184

0.206

0.228

0.250

222.jpg

0.765

0.800

0.802

0.805

0.783

0.748

0.705

η

0.770

0.824

0.846

0.840

0.821

0.796

0.760

333.jpg

0.115

0.135

0.150

0.170

0.190

0.210

0.235

LSA

19.2

18.9

19.1

19.9

21.2

22.83

24.88


Non-dimensional performance table of type Y9-38                                                                                             table 2

Code

1

2

3

4

5

6

7

111.jpg

0.12

 0.14

0.162

0.18

0.20

0.22

0.24

222.jpg

0.845

0.890

0.895

0.890

0.878

0.860

0.830

η

0.760

0.823

0.828

0.815

0.795

0.775

0.745

333.jpg

0.135

0.155

0.173

0.200

0.225

0.250

0.273

LSA

17.6

17.4

17.6

18.2

19.2

20.2

 21.8


1.Designer and user select induced drought fan №. in performance table according to the required flow rate and total pressure. The specific performance and the complete motor must be found out from table, but power and speed should be matched and note it when purchasing.

  
2.The performance of each speed in performance table is that the performance in the range of 90% maximum efficiency is divided into 7 performance points according to flow rate. Take performance table as a standard when purchasing. 


3.The performance of fan ex-works is that the value of total pressure under the given flow rate shall not exceed ±5%.

 
4.№4~№6.3 in Performance table is calculated with fume gas atmospheric temperature t=220℃、200℃, atmospheric pressure P=101325Pa, air density ρ=0.713, 0.745kg/m3, above №7.1 is calculated with fume gas atmospheric temperature t=200℃、175℃, atmospheric pressure P=101325Pa, air density ρ=0.745, 0.784kg/m3. The selecting curve and performance table of fan with damper indicate the parameter when the damper is full open(0℃).


5.When the operation condition is non-standard, the performance is calculated with following formula:

33.jpg


Where: P2, Q2, N2 indicate total pressure, flow rate and shaft power given in the performance table.
P —  use local atmosphere (Pa)
t—  temperature of delivering gas (℃)
t—  rated temperature given in performance table:
№4~№6.3  t2=220℃; above №7.1 t2=200℃,  
P1, Q1 and N1 indicate total pressure, flow rate and shaft power caused by fan under the specific operation condition.


6.The required power in the table of performance and optional part:

44.jpg

Where: Q、P、η separately means flow rate, total pressure and air efficiency of fan.
Unit: Q-(m3/h), P-(Pa), η1 is mechanical efficiency of fan; belt driving η1=0.95; coupling driving η=0.98, k-storing factor of motor power, take 1.3 for induced draught fan, the select motor power shall normally not less than the value of required power.


7.There are the following relation ship among Q(flow rate), P(total pressure), N(power ) and n(speed)when the inlet condition is not changed.

55.jpg

From the formula of item 5 total pressure and item 6 required power formula N,warn us that when motor capacity is not changed,prohibit the fan in cold and full speed running or arbitrarily increasing speed,otherwise there are danger of burn-out on motor due to overload. 


8. Treatment of excessive or insufficient flow rate:
The phenomenon of flow excess or insufficient often occurs when use, there are many reasons of occurring such phenomenon. If the phenomenon of flow some times large and sometimes small occurs during operation, or suddenly reduced within short time, the main reason is that the pipe net is plugged. The phenomenon of flow excess or insufficient will occur during normal running, the main reasons are as follows:
(1) The actual and calculated values of pipe net resistance is widely different. The normal pipe net characteristic equation: P=kQ2, Where: k―the coefficient of resistance, if the actual value k is less than the calculated value k ,the flow rate increases; vice versa, flow rate decreases, see fig.2 right.
(2) The effect of fan total pressure deviation △P have not been considered during selecting, when the actual total pressure of fan is positive deviation, the flow rate increases, and when it is negative deviation, the flow rate decreases, see fig.2 left.


The flow rate excess or insufficient occurred during fan operating can be adjusted by damper or gate. When the damper is full open, the flow rate is still insufficient, one of the following methods can be used to eliminate:
1. Change pipe net to reduce the coefficient K of resistance.
2. Increase fan speed,but it should not be more than that max. speed of the type given in the performance table.


66(001).jpg

Fig 2 The relationship between pipe net characteristic and total 


3. Select new fan with higher pressure.


SUPPLY SCOPE OF FAN UNIT
One induced draught fan, one damper, one driving motor, a pair of guide rail for motor, one set of anchor bolts.


PURCHASE INFORMATION
When purchasing, indicate the fan size, flow rate, pressure, discharge angle, rotation direction and the motor model, power and speed etc.


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