Performance and selection of the fan

Performance of the fan:The performance of the fan is expressed by the parameters of fan flow, full pressure, spindle speed, shaft power and so on. Performance curve and the performance of the performance given in the table. Blower performance:200 degrees Celsius, atmospheric pressure is 101325 Pascal,Gas density is 0.745kg/m³, calculation and calculation of air medium. (Other designs are similar to the use of parameters.)

The performance of both the selection curve and the performance table refers to the performance of adjusting the blade to a full 0 degree centigrade. When ordering the performance table shall prevail. Fan performance test total pressure value of 5% of the total pressure deviation is less than design value.

Such as fan using condition does not accord with the above, the performance shall be carried out according to the related formula conversion.

When excessive or insufficient flow of processing. When use, often occur the phenomenon of excessive or insufficient flow, produce a lot of reasons for this phenomenon, if it is in use process flow occurs when small phenomenon, is mainly due to the resistance of pipe network. If it is in use process, after a long time to reduce gradually, mainly due to network congestion.

After the fan is a new installation, a formal operation occurs when the flow phenomenon of excessive or insufficient reason mainly has the following points:

1. The actual value and calculating value difference is too large in the resistance of pipelines.

By the general network characteristic equation: P = Kq2, type of K - drag coefficient.

If the actual value K is less than the calculated value K, increases the flow, if the actual value K is greater than the calculated value K, the flow decreases.

2. when the choice is not the fan itself fully considering the influence of the pressure deviation of δP, when the fan actual total pressure for positive deviation, then the flow; Negative deviation, the flow rate decreases.

Began formal operation after fan is a new installation, or in use process flow is too big or too small, one of the following methods can be used to eliminate it.

Make use of the fan speed adjusting flow increase or decrease.

Using the new high or low pressure switch to increase or decrease in flow rate of fan.

Change the pipeline resistance coefficient K to change traffic.

At this time to try to change the network reduce drag coefficient to increase traffic, also can increase the fan rotation speed and changing the high pressure fan, but speed shall not be greater than the maximum speed performance table.

The basis and the shape of the fan

Y5-48 type fan shape and see the appended drawings

Installation and operation of the fan

 Before installation: Check all components of the fan to see weather any thing is missed; weather the impeller rotates in the same direction as the casing; weather all components are connected tightly and weather the impeller rotates freely.

During installation: Pay attention to check the casing and any tools or goods should not be dropped and remained inside the casing. The connecting face between the support of the fan and the foundation or between pads and foundation should be tight. Adjusting should be made to joint the fan with foundation surface and to connect the fan with suction, discharge duct naturally. Forced assembling, especially, applying weight of pipes on any components of the fan isimpermissible. Also, attention shall be paid to the horizontality of the fan.

Requirement of installation:

1. Install the fan according to the position and sizes shown on the drawing. To insure high efficiency, radial and axial clearances between inlet and impeller must be guaranteed.

2. After installation, turn, with a little force, the driving rotor to see if it is over tight or touched with stationary components.

3. Commission Can only be carried out after the unit is through the final inspection.

4. In order to prevent the motor being burnt out due to overloading, the fan can only be started up and tested without loading. If the case is ok, increase the load step by step until the rated operating condition is reached. Control the current strictly during operation to prevent it exceeding the rated value.

Operationof the fan:

  Before starting-up, the following preparations shall be made:

1) Close the valve of suction pipe and open a little the valve on discharge pipe.

2) Check the rotating and non –rotating parts to prevent colliding and friction.

3) After the fan is started-up and the normal speed is reached, check the bearing temperature is normal or not during the operation. If there is no special requirement for bearing temperature, the temperature rise of the bearing shall not exceed 40℃ of surrounding temperature. The value of even root vibration speed of the bearing shall comply with the following rules: rigid support(support is fixed on the foundation) Vrms≤4.6mm/s; flexible support(be set onfoundation or floor through absorber) Vrms≤7.1mm/s. In case that severe vibration, colliding, quick rise of bearing temperature and other abnormal phenomena are found, stop the fan immediately.

Maintenance of the fan

1. Don’t allow fan with trouble running.

2. Don’t freely change the maintenance person, specific person operating and repair the fan is preferred.

3. Regularly remove dust, contamination and the foreign materials and prevent rust .

4. Maintenance can be carried out during shut down of fan to assure operators safety.

5. When the fan is repaired, the motor switch must be monitored or locked.

6. Inspect the thermometer and oil indicator regularly.

7. During the star-up, shut-down or operation of the fan, if some abnormal thing happens, inspections shall be carried out immediately; if it is small failure, the reason shall be checked out and eliminated, if it is a big failure, the fan shall be stopped and inspection and maintenance shall be made immediately.

8. Except replacing the lubricant after overall, replace the lubricating oil periodically.

The main failure and reason of the fan

1) severe vibration of the fan

①friction between casing (or suction unit)and impeller.

②Foundation is not rigid enough or firm enough.

③loosing of rivets in impeller or deformation of impeller.

④Loose match of shaft with impeller disc

⑤Loose of connecting bolts between casing and support, and between motor and support.

⑥The installation of inlet and outlet ducts is improper which causes the casing deformation and resonance.

⑦Rotor unbalance caused by dust, contamination on blades, wear of blades, deformation of impeller and bending of shaft.

2) High rise of bearing temperature

①severe vibration

② lubricant is poor in quality, deteriorated, mixed with dust, sand, contamination and etc, or insufficient in quantity.

③Wornout of rolling bearing

3) Overcurrent and high temperature rise in motor.

① The valves on inlet and outlet pipes are not closed completely when starting-up.

② Input voltage is low or a single phase of power supply is cot out.

③ Influence caused by severe vibration

④ The speed of main shaft is bigger than the rated value.

Purchase information

When ordering, please the fan type, machine number, flow rate, full pressure, the transmission medium, the use of temperature, exit angle and rotation direction,etc..

If the user′s needs are not in conformity with the specifications provided in this manual, please contact the design department of our factory for special design.

 

Huashide(shandong)fan Co.，Ltd

Http:www.hsdfans.com

Add:kunmingrod.linyi.P.R.china

E-mail:17853928877@163.com

Tel: 17853928877