Boiler sealing fan inlet filter screen back flushing device

Abstract

The utility model discloses a boiler sealing fan inlet filter screen back flushing device, which belongs to the technical field of sealing fan filter screen cleaning, and comprises a primary fan and a cold primary air mother pipe connected to an air outlet of the primary fan, and a first pipeline and a second pipeline are arranged on the cold primary air mother pipe. The first pipeline is vertically connected to the side wall of the cold primary air mother pipe, a filter screen is arranged at a pipe opening, connected with the cold primary air mother pipe, of the first pipeline, and filter screen pressure difference alarm devices are arranged on the front pipeline and the rear pipeline of the filter screen; the second pipeline is formed by directly extending a cold primary air mother pipe and is sequentially communicated with an electrically operated gate, a secondary air box and a combustor, and the electrically operated gate is mounted below the pipeline of the filter screen. The electrically operated gate is arranged below the filter screen pipeline, when the filter screen is blocked due to accumulation of sundries, the electrically operated gate is opened to enable the cold primary air mother pipe to penetrate through the second pipeline, the sundries are blown to the secondary air box under the pressure of the cold primary air and enter the combustor to be combusted, and the sundries are cleaned.

Description

Technical Field

[0001] The utility model relates to the technical field of sealing fan filter screen cleaning, in particular to a boiler sealing fan inlet filter screen reverse flushing device. Background Art

[0002] The sealed fan provides sealed air for the positive pressure direct blowing pulverizing system, sealing the mixture of coal powder and air in the coal mill to prevent it from leaking out to pollute the environment or entering the roller bearing to cause bearing failure. In order to achieve the effect of the sealed coal mill, the outlet pressure of the sealed fan must be higher than the primary air pressure. Because when the sealed fan impeller rotates at high speed, a negative pressure is formed at the air inlet of the fan housing, and the air flow is from the air inlet to the impeller to the air outlet. Usually, a filter is installed at the air inlet of the sealed fan to prevent the air flow mixed with various solid impurities in the air from entering the fan body, reducing the wear of the fan impeller during high-speed rotation and protecting the fan impeller. However, the inlet filter is easy to clog, resulting in a decrease in the outlet pressure of the sealed fan, affecting the safe and stable operation of the unit. Especially when two sealed fans share an inlet filter, the filter cannot be replaced when the unit is running, and can only be replaced by knocking, etc., which is not ideal and increases the workload. If the unit is shut down for cleaning, the work efficiency will be greatly reduced.

[0003] For example, the patent with announcement number CN219965146U discloses an inlet filter screen device for a coal mill sealed fan, including an inlet filter screen device body arranged between the air main pipe and the coal mill, the inlet filter screen device body is composed of a pipeline and a filter screen inlet valve, a filter screen, a filter screen outlet valve, a sealed fan, a sealed fan outlet check valve and a sealed fan outlet valve arranged on the pipeline in sequence, one end of the pipeline is connected to the air main pipe, and the other end of the pipeline is connected to the coal mill, the filter screen on the pipeline is arranged on the side close to the air main pipe, and the sealed fan is arranged on the side close to the coal mill. Although this utility model ensures the reliable standby of another sealed fan during the maintenance of a single filter screen, it cannot be realized when two sealed fans share an inlet filter screen, and the cost is relatively high.

[0004] In view of this, the inventor conducted in-depth research on this demand, and thus the present case was produced. Utility Model Content

[0005] In order to overcome the problem in the prior art that when two sealed fans share an inlet filter, the filter cannot be replaced and the blockage cannot be cleaned in time when the unit is running, the utility model provides a boiler sealed fan inlet filter backwashing device, including a primary fan and a cold primary air main pipe connected to the primary fan outlet, the cold primary air main pipe is provided with two branches, a first pipe and a second pipe, the first pipe is vertically connected to the side wall of the cold primary air main pipe, and the first pipe is provided with a filter at the pipe mouth connected to the cold primary air main pipe, and a filter pressure difference alarm device is provided on the front and rear pipes of the filter; the second pipe is formed by directly extending the cold primary air main pipe, and is connected to an electric door, a secondary air box and a burner in sequence, and the electric door is installed below the pipe of the filter.

[0006] By installing the electric door below the filter duct and the second duct being directly extended from the cold primary air main duct, when the filter pressure difference alarm device detects that the filter is blocked due to accumulated debris, the electric door is opened to allow the cold primary air main duct to pass through the second duct, and then the cold primary air generated by the primary fan blows the debris to the secondary air box, and finally enters the burner for combustion, thereby completing the cleaning of the debris.

[0007] The specification of the cold primary air main pipe is DN1400, and the second pipe serves as the debris discharge pipe of the filter, with a specification of DN150, which is smaller than the diameter of the cold primary air main pipe. When the filter is in a normal and unblocked state, the electric door is in a closed state, and the unit operates normally. When the filter is in a blocked state and needs to be cleaned, the electric door can be opened to clean the debris.

[0008] Preferably, the filter pressure difference alarm device includes a first pressure detector for detecting the air pressure of the cold primary air main pipe, a second pressure detector for detecting the air pressure of the first pipe, a pressure difference display and a warning light. The output ends of the first pressure detector and the second pressure detector are both the pressure difference displays. When the pressure difference display shows that the pressure difference of the filter reaches 2KPa or above, the warning light will give an indication.

[0009] Preferably, the cold primary air generated by the primary fan enters the cold primary air main pipe.

[0010] Preferably, the pressure of the cold primary air in the cold primary air main pipe and the second pipe is 8-12 KPa.

[0011] Preferably, a motor is connected to the center axis position of the plane where the filter is located, and the motor rotating shaft drives the center axis of the plane where the filter is located to rotate. When the filter is blocked, the motor drives the filter to switch from a position perpendicular to the first pipe to a position parallel to the first pipe. The side of the filter close to the cold primary air main pipe faces the ground, and the electric door is opened. The filter is reversely flushed by the cold primary air in the cold primary air main pipe, and debris is blown away from the filter into the secondary air box and finally into the burner.

[0012] When lighter debris is deposited on the filter, it is difficult to blow the debris away only by wind pressure. The filter can be driven by the motor to rotate from a state perpendicular to the first pipe to a state parallel to the first pipe, and the side of the filter with impurities faces the ground. Under the action of gravity, the debris falls on the pipe of the filter, and then the electric door is opened to enable the cold primary air to blow the lighter debris deposited on the filter to the secondary air box and finally enter the burner. However, since the filter needs to filter the cold primary air passing through the first pipe, the time for the filter to rotate from a state perpendicular to the first pipe to a state parallel to the first pipe shall not exceed 10 minutes.

[0013] Preferably, the secondary air box is also connected to an air preheater and a blower, and the blower generates secondary air which passes through the air preheater, the secondary air box and the burner in sequence through a secondary air duct.

[0014] Preferably, the pressure of the secondary air in the secondary air duct is 0.2-0.5 KPa.

[0015] Preferably, the first pipe is located at one end away from the filter and is connected in parallel with a plurality of branch pipes, the connecting pipe after the filter is composed of at least two branch pipes parallel to each other, and the parallel branch pipes are sequentially connected with corresponding inlet baffle doors and sealing fans.

[0016] Preferably, the sealed fans on the parallel branch pipes are connected with a reversing baffle, and are finally gathered into a sealed air main pipe through the reversing baffle, and the outlet end of the sealed air main pipe is connected with a coal mill.

[0017] Preferably, when the sealed fan on any one of the parallel branch pipes is shut down for standby use, the cold primary air enters any one of the parallel branch pipes and is pressurized by the sealed fan, and the reversing baffle is automatically blown to the other side by the wind pressure to close the outlet of the sealed fan that is shut down for standby use.

[0018] The beneficial effects produced by adopting the technical solution of the utility model are as follows:

[0019] (1) An electric door is provided below the filter duct, and the second duct is directly extended from the cold primary air main duct. When the filter is blocked due to accumulated debris, the electric door is opened to allow the cold primary air main duct to pass through the second duct. Since the wind pressure of the cold primary air main duct is much greater than the wind pressure of the secondary air duct, the debris is blown to the secondary air box under the pressure of the cold primary air, enters the burner and is burned, thereby cleaning the debris.

[0020] (2) By arranging a filter pressure difference alarm device on the front and rear pipes of the filter, when the filter pressure difference high alarm indicates that the filter is blocked, when lighter debris is deposited on the filter, it is difficult to blow the debris away only by wind pressure. The filter is switched from a vertical position to a horizontal position, and the side of the filter close to the cold primary air main pipe faces the ground. The electric door is opened, and the filter is reversely flushed by the high-pressure cold primary air, so that the debris is blown away from the filter and enters the secondary air box, and finally enters the burner for combustion. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solution of the implementation mode of the utility model, the drawings required for use in the implementation mode will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 It is a schematic structural diagram of a preferred sealed fan inlet filter backwashing device of the utility model.

[0023] Figure 2 This is a schematic diagram of the preferred first pipeline and second pipeline structure of the utility model.

[0024] Among them, 1. primary fan; 2. cold primary air main pipe; 3. first pipeline; 4. second pipeline; 5. filter; 6. filter pressure difference alarm device; 7. electric door; 8. secondary air box; 9. burner; 10. air preheater; 11. blower; 12. secondary air duct; 13. branch duct; 14. inlet baffle door; 15. sealed fan; 16. reversing baffle; 17. sealed air main pipe; 18. coal mill. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of the embodiments of the utility model clearer, the technical solutions in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Therefore, the following detailed description of the embodiments of the utility model provided in the drawings is not intended to limit the scope of the utility model for which protection is sought, but merely represents the selected embodiments of the utility model. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model.

[0026] This implementation fully analyzes the problem that when two sealed fans share one inlet filter, the filter cannot be replaced during the operation of the unit and the blockage cannot be cleared in time, and designs a boiler sealed fan inlet filter reverse flushing device. The specific implementation is as follows:

[0027] like Figure 1-2 As shown, a boiler sealed fan inlet filter backwashing device includes a primary fan 1 and a cold primary air main pipe 2 connected to the air outlet of the primary fan 1, and the cold primary air main pipe 2 is provided with two branches, a first pipe 3 and a second pipe 4. The first pipe 3 is vertically connected to the side wall of the cold primary air main pipe 2, and the first pipe 3 is provided with a filter 5 at the pipe mouth connected to the cold primary air main pipe 2, and a filter pressure difference alarm device 6 is provided on the front and rear pipes of the filter 5; the second pipe 4 is directly extended from the cold primary air main pipe 2, and is connected with an electric door 7, a secondary air box 8 and a burner 9 in sequence, and the electric door 7 is installed below the pipe of the filter 5.

[0028] By installing an electric door 7 under the filter 5 pipe, and the second pipe 4 is directly extended from the cold primary air main pipe 2, when the filter pressure difference alarm device 6 detects that the filter 5 is blocked due to accumulated debris, the electric door 7 is opened to allow the cold primary air main pipe 2 to pass through the second pipe 4, and then the cold primary air generated by the primary fan 1 blows the debris to the secondary air box 8, and finally enters the burner 9 for combustion, thereby completing the cleaning of the debris.

[0029] The specification of the cold primary air main pipe 2 is DN1400, and the second pipe 4 is used as the debris discharge pipe of the filter 5, with a specification of DN150, which is smaller than the diameter of the cold primary air main pipe 2. When the filter 5 is in a normal and unblocked state, the electric door 7 is in a closed state, and the unit operates normally. When the filter 5 is in a blocked state and needs to be cleaned, the electric door 7 can be opened to clean the debris.

[0030] As a preferred embodiment, the filter pressure difference alarm device 6 includes a first pressure detector for detecting the wind pressure of the cold primary air main pipe 2, a second pressure detector for detecting the wind pressure of the first pipeline 3, a pressure difference display and a warning light. The output ends of the first pressure detector and the second pressure detector are both the pressure difference display. When the pressure difference display shows that the pressure difference before and after the filter 5 reaches 2KPa or more, the warning light will give an indication.

[0031] As a preferred implementation, the cold primary air generated by the primary fan 1 enters the cold primary air main pipe 2.

[0032] As a preferred embodiment, the pressure of the cold primary air in the cold primary air main pipe 2 and the second pipe 4 is 8-12 KPa.

[0033] As a preferred embodiment, a motor is connected to the center axis position of the plane where the filter 5 is located, and the rotating shaft of the motor drives the center axis of the plane where the filter 5 is located to rotate. When the filter 5 is blocked, the motor drives the filter 5 to switch from a position perpendicular to the first pipe 3 to a position parallel to the first pipe 3. The side of the filter 5 close to the cold primary air main pipe 2 faces the ground, and the electric door 7 is opened. The high-pressure cold primary air in the cold primary air main pipe 2 reversely flushes the filter 5, blows debris away from the filter 5 and enters the secondary wind box 8, and finally enters the burner 9.

[0034] When lighter debris is deposited on the filter 5, it is difficult to blow away the debris only by wind pressure. The filter 5 can be driven by the motor to rotate from a state perpendicular to the first pipe 3 to a state parallel to the first pipe 3, and the side of the filter 5 with impurities faces the ground. Under the action of gravity, the debris falls on the pipe of the filter 5, and then the electric door 7 is opened to blow the lighter debris deposited on the filter 5 to the secondary wind box 8 by the cold primary air, and finally enter the burner 9. However, since the filter 5 needs to filter the cold primary air passing through the first pipe 3, the time for the filter 5 to rotate from a state perpendicular to the first pipe 3 to a state parallel to the first pipe 3 shall not exceed 10 minutes.

[0035] As a preferred embodiment, the secondary air box 8 is also connected to an air preheater 10 and a blower 11 , and the blower 11 generates secondary air which passes through the air preheater 10 , the secondary air box 8 and the burner 9 in sequence through the secondary air duct 12 .

[0036] As a preferred implementation, the pressure of the secondary air in the secondary air duct 12 is 0.2-0.5 KPa.

[0037] As a preferred embodiment, the first pipe 3 is located at the end away from the filter 5 and is connected in parallel with several branch pipes, and the several branch pipes are composed of at least two mutually parallel branch pipes 13, and the parallel branch pipes 13 are sequentially connected with corresponding inlet baffle doors 14 and sealing fans 15.

[0038] As a preferred embodiment, the sealed fans 15 on the parallel branch pipes 13 are connected with a reversing baffle 16 and finally converged into a sealed air main pipe 17 through the reversing baffle 16. The outlet end of the sealed air main pipe 17 is connected with a coal mill 18.

[0039] As a preferred embodiment, when the sealed fan on any one of the parallel branch pipes is shut down for standby use, the cold primary air enters any one of the parallel branch pipes and is pressurized by the sealed fan, and the reversing baffle is automatically blown to the other side by the wind pressure to close the outlet of the sealed fan that is shut down for standby use.

[0040] Working principle example:

[0041] The primary air generated by the primary fan 1 enters the cold primary air main pipe 2 and then enters the first pipeline 3, then enters the branch pipeline 13 through the filter screen 5, passes through the inlet baffle door 14, enters the sealed fan 15, and is pressurized by the sealed fan 15 and led to the sealed air main pipe 17 by the reversing baffle 16 to provide sealed air to each coal mill 18. When the filter screen 5 is blocked due to accumulated debris, the filter screen high pressure difference alarm device 6 will issue an indication, and the crew can open the electric door 7 to allow the cold primary air main pipe 2 to pass through the second pipeline 4. Since the wind pressure of the cold primary air main pipe 2 is much greater than the wind pressure of the secondary air pipeline 12, the debris is blown to the secondary wind box 8 under the pressure of the cold primary air, enters the burner 9 and burns, so as to clean up the debris.

[0042] The above description is only the preferred implementation of the utility model, and is not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A boiler sealed fan inlet filter backwashing device, characterized in that: It includes a primary air fan and a cold primary air main pipe connected to the air outlet of the primary air fan, the cold primary air main pipe is provided with two branches, a first pipe and a second pipe, the first pipe is vertically connected to the side wall of the cold primary air main pipe, and a filter is provided at the pipe mouth of the first pipe connected to the cold primary air main pipe, and a filter pressure difference alarm device is provided on the pipes before and after the filter; the second pipe is formed by directly extending the cold primary air main pipe, and is connected with an electric door, a secondary air box and a burner in sequence, and the electric door is installed below the pipe of the filter.

2. A boiler sealed fan inlet filter backwashing device according to claim 1, characterized in that: The filter pressure difference alarm device includes a first pressure detector for detecting the air pressure of the cold primary air main pipe, a second pressure detector for detecting the air pressure of the first pipe, a pressure difference display and a warning light. The output ends of the first pressure detector and the second pressure detector are both the pressure difference display. When the pressure difference display shows that the pressure difference of the filter reaches 2KPa or more, the warning light will give an indication.

3. A boiler sealed fan inlet filter backwashing device according to claim 1, characterized in that: The cold primary air generated by the primary fan enters the cold primary air main pipe.

4. A boiler sealed fan inlet filter backwashing device according to claim 3, characterized in that: The pressure of the cold primary air in the cold primary air main pipe and the second pipeline is 8-12 KPa.

5. A boiler sealed fan inlet filter backwashing device according to claim 4, characterized in that: A motor is connected to the central axis position of the plane where the filter is located, and the rotating shaft of the motor drives the central axis of the plane where the filter is located to rotate. When the filter is blocked, the motor drives the filter to switch from a position perpendicular to the first pipe to a position parallel to the first pipe. The side of the filter close to the cold primary air mother pipe faces the ground, and the electric door is opened. The cold primary air in the cold primary air mother pipe back-flushes the filter, blowing debris away from the filter into the secondary air box and finally into the burner.

6. A boiler sealed fan inlet filter backwashing device according to claim 1, characterized in that: The secondary air box is also connected to an air preheater and a blower. The blower generates secondary air which passes through the air preheater, the secondary air box and the burner in sequence through a secondary air duct.

7. A boiler sealed fan inlet filter backwashing device according to claim 6, characterized in that: The pressure of the secondary air in the secondary air duct is 0.2-0.5 KPa.

8. A boiler sealed fan inlet filter backwashing device according to claim 1, characterized in that: The first pipe is located at one end away from the filter and is connected in parallel with a plurality of branch pipes. The connecting pipe after the filter is composed of at least two branch pipes parallel to each other. The parallel branch pipes are sequentially connected with corresponding inlet baffle doors and sealing fans.

9. A boiler sealed fan inlet filter backwashing device according to claim 8, characterized in that: The sealed fans on the parallel branch pipes are connected with a reversing baffle and finally converged into a sealed air main pipe through the reversing baffle. The outlet end of the sealed air main pipe is connected with a coal mill.

10. A boiler sealed fan inlet filter backwashing device according to claim 9, characterized in that: When the sealed fan on any one of the parallel branch pipes is shut down for standby use, the cold primary air enters any one of the parallel branch pipes and is pressurized by the sealed fan, and the reversing baffle is automatically blown to the other side by the wind pressure to close the outlet of the sealed fan that is shut down for standby use.

Images