Shaft seal air leakage structure of rotary air preheater

Abstract

The utility model relates to the technical field of air preheating equipment sealing, and discloses a rotary air preheater shaft seal air leakage structure which comprises a shell and a rotating shaft, the rotating shaft is rotationally arranged in the shell, a first sealing cover is arranged at the upper end of the shell, a second sealing cover is arranged at the upper end of the first sealing cover, and a first partition plate is arranged on the inner wall of the first sealing cover. A first partition plate is arranged on the inner wall of the first sealing cover and divides the interior of the first sealing cover into a first cavity and a second cavity, a second partition plate is arranged on the inner wall of the second sealing cover and divides the interior of the second sealing cover into a third cavity and a fourth cavity, the first cavity communicates with a first air outlet pipe, the second cavity communicates with an air inlet pipe, and the fourth cavity communicates with a second air outlet pipe. The second air outlet pipe communicates with the first air outlet pipe, the first air outlet pipe is connected with an exhaust fan, and the output end of the exhaust fan communicates with the flue. By increasing the air pressure in the first sealing cover and the second sealing cover, dust-containing hot air leaked from the shell is reduced, and finally leaked gas is exhausted into the flue through the exhaust fan, so that the working environment is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of air preheating equipment sealing, in particular to a shaft seal air leakage structure of a rotary air preheater. Background Art

[0002] The air preheater of a thermal power plant boiler is an important auxiliary equipment of the boiler. It is responsible for reducing the exhaust gas temperature and heating the boiler combustion air to achieve the purpose of stabilizing boiler combustion and improving boiler efficiency.

[0003] The sealing device of the dynamic and static parts of the existing rotary air preheater rotor adopts packing seal. It can prevent air leakage in the initial stage of operation after maintenance. However, after a period of operation, the dynamic and static parts seals begin to leak high-temperature dusty hot air (temperature reaches above 300℃), resulting in dust filling on site, poor hygiene, high ambient temperature, and excessive temperature of the air preheater bearing. Only by temporarily installing a fan for forced ventilation and cooling can the bearing temperature be kept within the normal range. For this reason, we propose a rotary air preheater shaft seal leakage structure to solve the above problem. Utility Model Content

[0004] The utility model aims to provide a rotary air preheater shaft seal air leakage structure to solve the problem of dust-laden hot air leaking from the dynamic and static parts of the packing seal after a period of time.

[0005] In order to achieve the above-mentioned purpose, the utility model adopts the following technical solutions: a rotary air preheater shaft seal air leakage structure, comprising a shell and a rotating shaft, the rotating shaft is rotatably arranged in the shell, a filler is arranged between the rotating shaft and the shell, the shell is provided with a pressing end cover, the pressing end cover is used to fix the filler, a first sealing cover is provided at the upper end of the shell, a second sealing cover is provided at the upper end of the first sealing cover, the first sealing cover and the second sealing cover are both wrapped around the outside of the rotating shaft, a first partition is provided on the inner wall of the first sealing cover, the first partition divides the interior of the first sealing cover into a first chamber and a second chamber, and the second A second partition is provided on the inner wall of the sealing cover, and the second partition divides the interior of the second sealing cover into a third chamber and a fourth chamber, and the first chamber, the second chamber, the third chamber and the fourth chamber are connected to each other, the first chamber is connected to a first air outlet pipe, the second chamber is connected to an air inlet pipe, the fourth chamber is connected to a second air outlet pipe, the second air outlet pipe is connected to the first air outlet pipe, the first air outlet pipe is connected to an exhaust fan, and the output end of the exhaust fan is connected to the flue, and an annular gap is provided between the first sealing cover, the first partition, the second sealing cover and the second partition and the rotating shaft.

[0006] The beneficial effects of this program are:

[0007] This solution allows for leakage of some dust-laden hot air from the moving and static parts of the air preheater shaft. Normal-temperature compressed air is introduced into the first sealed cover through the air inlet pipe. Since the first, second, third, and fourth chambers are interconnected, compressed air is sent into each chamber, increasing the air pressure in each chamber and reducing the pressure difference between the inside and outside of the shell and each chamber, thereby reducing the leakage of dust-laden hot air from the shell. At the same time, the small amount of dust-laden hot air leaking from the shell can be locked, preventing it from leaking from the second sealed cover to the external environment.

[0008] Then, the exhaust fan connected to the first air outlet pipe is used to drain the first chamber and the fourth chamber connected to the first air outlet pipe through the second air outlet pipe, so that the dust-laden hot air leaked into the first chamber and the fourth chamber is discharged from the air preheater, thereby preventing dust from accumulating and clogging the seal between the rotating shaft and the shell, thereby raising the rotating shaft temperature and causing the bearing temperature to rise;

[0009] In addition to increasing the pressure inside each chamber and reducing the leakage of dust-laden hot air, the compressed air can also reduce the ambient temperature inside each chamber. At the same time, since the air pressure in the fourth chamber is greater than the air pressure in the external environment, the room temperature air in the external environment leaks into the third chamber from the seal between the rotating shaft and the second sealing cover, which can cool the dynamic and static seals between the rotating shaft and the second sealing cover, reduce the temperature of the rotating shaft, and avoid raising the temperature of the rotating shaft after the first sealing cover and the second sealing cover are installed. The dust-laden hot air is discharged into the flue, and the impact on the safety, reliability and economy of subsequent equipment is basically negligible.

[0010] Preferably, as an improvement, the first chamber, the second chamber and the fourth chamber are all provided with pressure gauges.

[0011] The beneficial effect is that the air pressure value inside each chamber can be intuitively observed through the pressure gauge provided in each chamber, thereby better adjusting the air pressure of each chamber.

[0012] Preferably, as an improvement, the air inlet pipe, the first air outlet pipe and the second air outlet pipe are all provided with valves.

[0013] The beneficial effect is that by arranging valves on the air inlet pipe, the first air outlet pipe and the second air outlet pipe, the air pressure inside each chamber can be better controlled, thereby reducing the leakage of dust-laden hot air.

[0014] Preferably, as an improvement, the annular gaps between the first sealing cover, the first partition plate, the second sealing cover, and the second partition plate and the rotating shaft are set to 0.5-1 mm.

[0015] The beneficial effect is: by setting an annular gap of 0.5-1mm, direct contact between the first sealing cover, the first partition, the second sealing cover and the second partition and the rotating shaft can be prevented, thereby reducing friction and extending the service life of the rotating shaft. The existence of the annular gap helps air flow and reduces the temperature of the rotating shaft during rotation, thereby improving the thermal stability of the equipment.

[0016] Preferably, as an improvement, the first sealing cover is fixed to the outside of the shell by welding, and the second sealing cover is also fixed to the upper end of the first sealing cover by welding.

[0017] The beneficial effect is that fixing by welding can increase the airtightness inside the first sealing cover and the second sealing cover, and prevent gas leakage in each chamber. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the mechanism of the shaft seal air leakage structure of the rotary air preheater according to an embodiment of the present utility model. DETAILED DESCRIPTION

[0019] The following is further described in detail through specific implementation methods:

[0020] The figure marks in the drawings of the specification include: shell 1, rotating shaft 2, filler 3, pressing end cover 4, first sealing cover 5, second sealing cover 6, first partition 7, first chamber 8, second chamber 9, second partition 10, third chamber 11, fourth chamber 12, first air outlet pipe 13, air inlet pipe 14, second air outlet pipe 15, exhaust fan 16, pressure gauge 17, valve 18.

[0021] Example

[0022] The embodiment is basically as shown in the attached Figure 1 As shown, Figure 1The rotary air preheater shaft seal leakage structure shown in the figure includes a shell 1 and a rotating shaft 2, the rotating shaft 2 is the air preheater rotor, the rotating shaft 2 is rotatably arranged in the shell 1, the rotating shaft 2 and the shell 1 are filled with filler 3, the shell 1 and the rotating shaft 2 are fixedly installed with a pressing end cover 4 by bolts, the pressing end cover 4 is used to fix the filler 3, the upper end of the shell is fixedly installed with a first sealing cover 5 by welding, the upper end of the first sealing cover 5 is fixedly installed with a second sealing cover 6 by welding, the first sealing cover 5 and the second sealing cover 6 are both wrapped around the outside of the rotating shaft 2, the inner wall of the first sealing cover 5 is provided with a first partition 7, the first partition 7 divides the interior of the first sealing cover 5 into a first chamber 8 and a second chamber 9, the inner wall of the second sealing cover 6 is provided with a There is a second partition 10, which divides the interior of the second sealing cover 6 into a third chamber 11 and a fourth chamber 12 evenly, and the annular gap between the first sealing cover 5, the first partition 7, the second sealing cover 6 and the second partition 10 and the rotating shaft 2 is set to 0.5-1mm. The first chamber 8, the second chamber 9, the third chamber 11 and the fourth chamber 12 are connected to each other through the annular gap. The first chamber 8 is connected with a first air outlet pipe 13, the second chamber 9 is connected with an air inlet pipe 14, the fourth chamber 12 is connected with a second air outlet pipe 15, the second air outlet pipe 15 is connected with the first air outlet pipe 13, the first air outlet pipe 13 is connected with an exhaust fan 16, and the output end of the exhaust fan 16 is connected to the flue.

[0023] The first chamber 8 , the second chamber 9 and the fourth chamber 12 are all provided with pressure gauges 17 , and the air inlet pipe 14 , the first air outlet pipe 13 and the second air outlet pipe 15 are all provided with valves 18 .

[0024] The specific implementation process is as follows:

[0025] By adjusting the valve 18 at the upper end of the air inlet pipe 14, normal temperature compressed air is introduced into the first sealing cover 5. Since the first chamber 8, the second chamber 9, the third chamber 11 and the fourth chamber 12 are interconnected through an annular gap of 0.5-1 mm, the compressed air enters each chamber, causing the air pressure in each chamber to increase. At this time, by observing the pressure gauges 17 of the first chamber 8, the second chamber 9 and the fourth chamber 12, and then adjusting the air valves connected to the air inlet pipe 14, the first air outlet pipe 13 and the second air outlet pipe 15, the air pressure in the first chamber 8 and the fourth chamber 12 is adjusted, so that the air pressure in the first chamber 8 is slightly lower than the air pressure inside the shell 1, and the air pressure in the fourth chamber 12 is slightly lower than the air pressure in the fourth chamber 12. The air pressure is lower than that of the external environment, thereby reducing the amount of dust-laden hot air leaking from the shell 1 into the first chamber 8. At the same time, the fourth chamber 12 can also lock a small amount of dust-laden hot air leaking from the shell 1, so that it cannot leak from the second sealing cover 6 to the external environment. Finally, the exhaust fan 16 connected to the first air outlet pipe 13 is used to drain the first chamber 8 and the fourth chamber 12 connected to the first air outlet pipe 13 through the second air outlet pipe 15, so that the dust-laden hot air leaked into the first chamber 8 and the fourth chamber 12 is discharged from the air preheater, avoiding dust accumulation and clogging at the sealing part of the rotating shaft 2 and the shell 1, thereby preventing the dust-laden hot air from leaking into the external environment, which not only improves the working environment but also reduces the ambient temperature.

[0026] In addition to increasing the pressure inside each chamber and reducing the leakage of dust-laden hot air, the compressed air can also reduce the ambient temperature inside each chamber. At the same time, since the air pressure in the fourth chamber 12 is lower than the air pressure in the external environment, the room temperature air in the external environment leaks into the fourth chamber 12 from the seal between the rotating shaft 2 and the second sealing cover 6, which can cool the dynamic and static seals between the rotating shaft 2 and the second sealing cover 6, reduce the temperature of the rotating shaft 2, and avoid raising the temperature of the rotating shaft 2 after the first sealing cover 5 and the second sealing cover 6 are installed.

[0027] The above description is merely an embodiment of the present invention, and the commonly known specific technical solutions and / or features of the solution are not described in detail here. It should be noted that for those skilled in the art, without departing from the technical solution of the present invention, several variations and improvements can be made, which should also be considered as the scope of protection of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection claimed in this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A rotary air preheater shaft seal air leakage structure, comprising a housing and a rotating shaft, wherein the rotating shaft is rotatably arranged in the housing, a packing is arranged between the rotating shaft and the housing, and the housing is provided with a pressing end cover for fixing the packing, characterized in that: A first sealing cover is provided at the upper end of the shell, and a second sealing cover is provided at the upper end of the first sealing cover. The first sealing cover and the second sealing cover are both wrapped around the outside of the rotating shaft. A first partition is provided on the inner wall of the first sealing cover, and the first partition divides the interior of the first sealing cover into a first chamber and a second chamber. A second partition is provided on the inner wall of the second sealing cover, and the second partition divides the interior of the second sealing cover into a third chamber and a fourth chamber. The first chamber, the second chamber, the third chamber and the fourth chamber are interconnected, the first chamber is connected with a first air outlet pipe, the second chamber is connected with an air inlet pipe, the fourth chamber is connected with a second air outlet pipe, the second air outlet pipe is connected with the first air outlet pipe, the first air outlet pipe is connected with an exhaust fan, and the output end of the exhaust fan is connected to the flue. An annular gap is provided between the first sealing cover, the first partition, the second sealing cover and the second partition and the rotating shaft.

2. The rotary air preheater shaft seal air leakage structure according to claim 1, characterized in that: The first chamber, the second chamber and the fourth chamber are all provided with pressure gauges.

3. The rotary air preheater shaft seal air leakage structure according to claim 2, characterized in that: The air inlet pipe, the first air outlet pipe and the second air outlet pipe are all provided with valves.

4. The rotary air preheater shaft seal air leakage structure according to claim 3, characterized in that: The annular gaps between the first sealing cover, the first partition, the second sealing cover, the second partition and the rotating shaft are set to 0.5-1 mm.

5. The rotary air preheater shaft seal air leakage structure according to claim 1, characterized in that: The first sealing cover is fixed to the outside of the shell by welding, and the second sealing cover is also fixed to the upper end of the first sealing cover by welding.

Images