How to install FD fan, ID fan and flue gas dust in the gas-fired boiler system?

1. After boiler body, economizer, air pre-heater, dust collector, etc are in place and installed, connect FD fan, ID fan, etc according to drawing and then connect corresponding flue gas duct. After fan in place, alignment between foundation and equipment base should be conducted with parallels. Fan position alignment should center on a shaft, central elevation deviation and vertical and lateral central line positional deviation should be 10mm or less and fan spindle should be in level state. The foundation that placing parallels shall be smooth to ensure that parallels are linked well with foundation, the contact surface shall be larger than 75% between parallels and foundation and weight of inlet and outlet flue gas duct shall not load on the fan shell.

2. To prevent rust and reduce disassembly difficulty, some grease shall be painted on the fan joint surface.

3. Any sundries should not be remained inside the shell. If there's dowel pin on the joint surface, fasten the dowel pin before fix the joint surface bolt.

4. Install fan according to drawing and the clearance between air inlet and impeller must comply with the design requirements. Fan spindle should be horizontal. Concentricity of spindle and motor shaft, coupling end face parallelism or pulley groove dislocation should comply with the permissible deviation as follows:

5. Permissible deviation of two shaft non-concentricity is 0.05mm.

6. Permissible deviation of coupling end plate parallelism is 0.1mm.

7. Permissible deviation of pulley groove dislocation is 0.5mm.

8. When installing the fan air damper, pay attention that air inlet direction should be consistent with the impeller rotation direction, otherwise it will lead to fan output decreases and running vibration increases. The damper opening degree and angle should be consistent with the indicating arrow. Switch should be flexible and there should be 2 ~ 3mm clearance between the baffles.

9. Fan bearing box is equipped with pipes to cool lubricating oil, when connecting inlet and outlet water pipe, check piping system for leakage phenomenon. Cooling water pipes should be orderliness, installed firmly and beautifully. There should be 3% downstream slope of drain pipes.

10. After FD fan and ID fan installation, check if there are defects like friction, leakage, etc. Then do the rotation lest, and identify the installation quality and promptly eliminate possible faults in the operation. In test run, check if the motor rotation is correct. Check it there is friction and vibration phenomenon. Check the motor temperature is normal or not, generally not higher than room temperature 40 ~ 70°C. When ID fan cold test run and cold furnace start up, running time shall not be more than 5 minutes, and should turn down the air damper of flue gas duct to prevent multiply motor load during cold operation which will burn out the motor. The newly installed fan should be continuous running for more than 2 hours under normal working condition.

11. The dimension of flue gas duct and chimney, flue gas duct installation elevation and vertical and horizontal size shall conform to the requirements of drawings. During the connection of flue gas duct with flue gas duct and flue gas duct with equipment flange, the asbestos rope should be clipped in the middle, connecting bolts should be complete, connection should be even and tight, and the bolts should be tightened to prevent air leakage.

12. With the method of hanging vertical wire to check the perpendicularity of the chimney, if there is any deviation, level up to correct it at the flange joint. Chimney fixed by steel wire rope, the steel wire rope should be fastened by flange bolts. Pay attention that tension level of three wire ropes is roughly equal, wire rope horizontal angle is 120°, and vertical angel of wire rope and chimney is not less than 60°. The chimney height should be comply with Emission Standard of Air Pollutants for industrial Boiler GB13271, boiler room design requirements or requirements of local environmental protection department.

13. Low temperature flue gas duct of gas fired boiler may produce large amount of condensate. Each flue gas connection and chimney bottom should adopt welding connection or reliable seal if possible and set condensate drain line.