DG85-80X (7-12) type sub-high pressure boiler feed water pump is a single-shell, single-suction segmented centrifugal pump water pump, used to transport clean water with a temperature lower than 160°C. It is mainly used for the comprehensive utilization of energy in the light and textile industry and the feed water for sub-high pressure boilers in small and medium-sized thermal power plants. It can also be used to transport other physical and chemical properties that contain insoluble solid impurities≦0.25% and water-soluble solid impurities≦5%. medium.
Disassembly work of DG85-80X (7-12) sub-high pressure boiler feed water pump
1. Preparatory work before disassembly of the sub-high pressure boiler feed water pump
(1) Check the closing of the power switch, and pay attention to prevent accidental closing of the drive switch;
(2) Close the shut-off valves of all water supply and drainage pipelines;
(3) Drain the water in the pump cavity and the lubricating oil in the two bearing boxes;
(4) Remove relevant instruments, oil pipelines and cooling water pipelines as needed;
(5) Check the alignment of the coupling, check and record the gap δ between the pump coupling and the motor coupling, the surface deviation δ1 and the circle deviation δ2, so that δ1-δ2≦0.06mm, δ3≦0.08mm;
(6) Disassemble the entire pump operation location.
2. Disassembly of the sub-high pressure boiler feed water pump
In the process of disassembly, measurements and records should be made in accordance with the technical requirements of the general drawing, and the assembly sequence and orientation should be marked to indicate which level it is. When reinstalling the pump, the installation sequence should be strictly carried out. During the disassembly process, the finishing surface should be protected to prevent bumps and scratches. If necessary, the exposed part can be wrapped.
Disassemble bearing lubricating oil, balance return water, leaking water and pressure gauge pipelines respectively.
The disassembly starts from the non-drive end:
(1) Remove the bearing gland, bearing cover and upper bearing bush, and then remove the bearing body and dust plate;
(2) Disassemble the water-cooled packing gland, bearing frame and balance chamber cover;
(3) Disassemble the small round nut, shaft end sleeve, shaft sleeve, balance plate and balance stop sleeve in sequence;
(4) Disassemble the balance plate and balance sleeve;
(5) After removing the pump cover, check the distance between the front and rear sections and their parallelism;
(6) Disassemble the through bars (reserve two temporarily), hoist the rear section, the middle section and the shaft to be dismantled must have a support frame (for disassembly), and then remove the guide vanes from the rear section;
(7) Remove the toothed cushion, the last stage impeller and the flat key;
(8) Remove the middle section and guide vanes of the last stage;
(9) Remove the impeller stop sleeve;
(10) Remove the impeller to the first stage according to the above sequence;
(11) Remove the coupling, the bearing at the drive end and the pump bracket;
(12) Remove the shaft and the two through bars.
