Safety technology of the hottest suction fan and f

2022-08-02
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Safety technology of suction fan and flue

suction fan is one of the indispensable auxiliary equipment of negative pressure boiler. The pressure head generated by the suction fan is used to discharge the flue gas to the atmosphere through the chimney, and maintain a certain negative pressure in the furnace, so that the combustion can proceed normally

the suction fan is a rotating equipment for conveying boiler flue gas. The flue gas entering the suction fan has a high temperature and contains various corrosive gases and a certain concentration of dust. Therefore, the suction fan works in a harsh environment. During operation, due to wear and ash accumulation, the suction fan may be forced to stop due to excessive vibration. In order to ensure the safe operation of the suction fan, the design, manufacture, installation, maintenance and operation of the suction fan must have higher requirements than that of the forced draft fan

this section mainly introduces the safety technical requirements for the operation characteristics of the suction fan

tensile testing machine fixture with spraying carborundum 1 Safety requirements for preventing vibration of suction fan

1) the suction fan of combustion boiler shall take corresponding anti-wear measures according to the dust content of flue gas and the efficiency of dust collector. Uneven wear causes unbalance of the impeller and vibration. For the impeller with wing type hollow blade, if the blade is worn through, the ash will enter the blade, causing serious vibration of the fan. It is suggested that wing type blades should not be used for flue gas with large ash content

2) for boilers with wet dust removal equipment, measures shall be taken to prevent ash deposition on blades. First, to ensure the normal operating conditions of the water film dust collector, to prevent the flue gas at the outlet of the dust collector from carrying water, and to reduce the dust humidity are the fundamental measures to solve the ash deposition on the blades; In addition, the blades shall be cleaned regularly. Clean up the accumulated dust on the blade every time. It is not allowed to eliminate the vibration by balancing and adding weight blocks

3) during the maintenance of the suction fan, all parts of the impeller shall be carefully checked without deformation. The clearance between the impeller and the air inlet ring shall be uniform without friction. The fastening screws of impeller and hub shall not be loose, and the hub and shaft shall be firmly assembled

4) the foundation screws of fan shell, motor and bearing seat and the matching screws of bearing cover shall be firm and free from loosening and unscrewing

5) when the fan is in normal operation, it is also related to the safety problems of every worker caused by the reduction of coke purchase price of 30 yuan/ton by Nippon Steel in East China. The bearing temperature and vibration shall meet the requirements of the regulations to ensure the normal lubrication of the bearing

6) for the negative suction machine supported on both sides, sufficient axial expansion clearance shall be reserved at the end bearing seat to adapt to the free expansion of the main shaft after being heated during operation, so as to prevent the bearing seat from being damaged or the bearing from being heated, resulting in fan vibration

7) after maintenance, the alignment of the coupling shall be carefully carried out, and the error shall be within the allowable range of the specification

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