Furnace rear lower secondary air pipe outlet blowing assisting device

Abstract

The utility model discloses a furnace rear lower secondary air pipe outlet blowing assisting device which comprises a pulverized coal furnace, the pulverized coal furnace is provided with a primary air pipe and a secondary air pipe, one end, close to the pulverized coal furnace, of the primary air pipe is provided with a combustion device, one end, close to an air outlet, of the secondary air pipe is provided with a blowing assisting pipe, and the other end of the blowing assisting pipe is connected with a fan. The blowing assisting pipe extends into the secondary air pipe, an air blowing opening of the blowing assisting pipe is aligned with an air outlet of the secondary air pipe and located in the center of the secondary air pipe, the blowing assisting pipe is provided with a valve body, and the valve body controls circulation of air flow in the blowing assisting pipe. According to the blowing assisting device for the outlet of the lower secondary air pipe behind the furnace, the blowing assisting pipe is additionally arranged for blowing, ash deposition and hardening at the opening of the secondary air pipe are avoided, the requirement for secondary air volume use after deep peak regulation of a unit is met, economic operation of a secondary fan is enhanced, the service life of the fan is prolonged, repair welding work of maintainers is reduced, and safety accidents of operators are completely eradicated.

Description

Technical Field

[0001] The utility model relates to the technical field of coal powder furnace air ducts, in particular to a primary and secondary air duct outlet structure behind a coal powder furnace. Background Art

[0002] A pulverized coal boiler is a boiler equipment that uses pulverized coal as fuel. It has the advantages of rapid and complete combustion, large capacity, high efficiency, adaptability to a wide range of coal types, and easy control and adjustment. The combustion characteristic of a pulverized coal boiler is that the fuel enters the combustion chamber together with the air and burns in a suspended state.

[0003] At present, the outlet of the lower secondary air duct behind the furnace relies on secondary air for transportation. (1) Disadvantages: Since the outlet of the lower secondary duct is at a relatively low distance from the furnace air distribution plate, when the unit meets the conditions for deep peak regulation and the lower secondary air duct is running at low load, the secondary air volume is reduced, which is easy to cause the backflow of the primary air in the furnace, causing dust accumulation and hardening at the mouth of the secondary air duct. Long-term operation of the unit will cause the diameter of the secondary air duct mouth to become smaller, which will have a very large impact on the subsequent increase in the load of the unit and the output of the secondary fan. There are safety hazards in the normal operation of the unit, which poses a considerable problem for the daily operation of the operating personnel. (2) Disadvantages: Due to the reduction in the secondary air volume, the backflow of the primary air in the furnace causes the temperature of the secondary air duct mouth to rise, causing the secondary air duct to burn red. The material of the secondary air duct is ordinary carbon steel, which will be carbonized at high temperature for a long time, which is easy to cause the weld to crack. Maintenance personnel need to frequently repair and reinforce the welds of the secondary air duct. There is a risk of high temperature burns for the operating personnel, which poses a great safety hazard to the safety of the operating personnel. In order to solve the above problems, it is necessary to make technical improvements to the existing technology. Utility Model Content

[0004] The utility model aims to provide a blowing-assisting device at the outlet of the lower secondary air duct behind a furnace, so as to solve the problems raised in the above-mentioned background technology.

[0005] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0006] The auxiliary blowing device at the outlet of the lower secondary air duct behind the furnace comprises a pulverized coal furnace, which is equipped with a primary air duct and a secondary air duct. A combustion device is arranged at one end of the primary air duct close to the pulverized coal furnace, and an auxiliary blowing pipe is arranged at one end of the secondary air duct close to the air outlet, and the other end of the auxiliary blowing pipe is connected to a fan.

[0007] As a further solution of the utility model: the auxiliary blowing pipe extends to the inside of the secondary air duct, the blowing port of the auxiliary blowing pipe is aligned with the air outlet of the secondary air duct, and is located at the center of the secondary air duct.

[0008] As a further solution of the utility model: the blowing-assisting pipe is installed with a valve body, and the valve body controls the circulation of the airflow in the blowing-assisting pipe.

[0009] As a further solution of the utility model: the auxiliary blowing pipe is provided with an air distribution line, the air distribution line is connected to a metal hose, and the metal hose is equipped with a valve body.

[0010] As a further solution of the utility model: the air distribution pipeline is connected to a flow-increasing pipeline through a three-way valve, and the other end of the flow-increasing pipeline is connected to the primary air duct.

[0011] As a further solution of the utility model: a bend pipe is provided at the location where the auxiliary blowing pipe is installed in the secondary air duct, and the auxiliary blowing pipe penetrates the bend pipe and extends to the inside.

[0012] As a further solution of the utility model: an oil distribution duct is arranged on the top of the combustion device.

[0013] Compared with the prior art, the beneficial effects of the utility model are:

[0014] The auxiliary blowing device at the outlet of the secondary air duct at the rear of the furnace adds an auxiliary blowing pipe for cleaning, which avoids dust accumulation and compaction at the outlet of the secondary air duct, meets the secondary air volume requirement after deep peak regulation of the unit, strengthens the economic operation of the secondary fan, extends the service life of the fan, reduces the repair welding work of maintenance personnel, and prevents safety accidents for operating personnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of a blowing-assisting device at the outlet of the lower secondary air duct behind the furnace;

[0016] Figure 2 It is a structural schematic diagram of a primary air duct in a blowing device at the outlet of a secondary air duct behind a furnace;

[0017] Figure 3 The present invention is a schematic diagram of the structure of the secondary air duct in a blowing-assisting device at the outlet of the secondary air duct behind a furnace.

[0018] In the figure: 1. Pulverized coal furnace; 2. Secondary air duct; 3. Primary air duct; 4. Blowing-assisting pipe; 5. Fan; 6. Flow-increasing pipeline; 7. Three-way valve; 8. Air distribution pipeline; 9. Metal hose; 10. Seal; 11. Oil air distribution duct; 12. Combustion device; 13. Elbow. DETAILED DESCRIPTION

[0019] See also Figures 1 to 3In the embodiment of the utility model, the blowing device at the outlet of the lower secondary air duct behind the furnace comprises a pulverized coal furnace 1, the pulverized coal furnace 1 is equipped with a primary air duct 3 and a secondary air duct 2, a combustion device 12 is arranged at one end of the primary air duct 3 close to the pulverized coal furnace 1, a blowing pipe 4 is arranged at one end of the secondary air duct 2 close to the air outlet, and the other end of the blowing pipe 4 is connected to the fan 5, and the blowing device of the secondary air duct 2 consists of two parts; the first part is inside the secondary air duct 2, and the lower part of the bend 13 of the 8 lower secondary air ducts 2 behind the pulverized coal furnace 1 is opened to extend the φ76 stainless steel pipes from the opening position into the interior of the secondary air duct by 40cm, and the blowing pipe 4 extends to the secondary air duct 2, the blowing port of the auxiliary blowing pipe 4 is aligned with the air outlet of the secondary air duct 2, and is located at the center of the secondary air duct 2. The position is determined from the inside of the secondary air duct 2 to ensure that the auxiliary blowing pipe 4 is at the center of the secondary air duct 2 to prevent the auxiliary blowing pipe 4 from tilting or pressing down. After determining the position, the open hole weld and the auxiliary blowing pipe 4 are fully welded, and the fan 5 works to send air from the auxiliary blowing pipe 4 to clean the air outlet of the secondary air duct 2 to avoid dust accumulation and hardening at the mouth of the secondary air duct 2, so as to meet the use of secondary air volume after deep peak regulation of the unit, strengthen the economic operation of the secondary air duct 2, extend the service life of the fan, reduce the repair welding work of maintenance personnel, and prevent safety accidents of operating personnel.

[0020] In a preferred embodiment, the blowing-assisting pipe 4 is installed with a valve body, which controls the flow of air in the blowing-assisting pipe 4. When the secondary air duct 2 does not need the blowing-assisting pipe 4, the valve body is closed and the fan 5 stops working. The airflow in the secondary air duct 2 will not be attenuated due to the diversion of the blowing-assisting pipe 4.

[0021] In a preferred embodiment, an oil air distribution pipe 11 is provided on the top of the combustion device 12, and an air distribution line 8 is provided on the auxiliary blowing pipe 4. The air distribution line 8 is connected to a metal hose 9, and the metal hose 9 is equipped with a valve body. The air distribution line 8 and the oil are mixed through a venturi tube and sent into the combustion device 12. The speed of the oil becomes faster under the transportation of the airflow, the spray range becomes larger, the combustion is more complete, and it is easier to control.

[0022] In a preferred embodiment, the air distribution line 8 is connected to the flow increase line 6 through a three-way valve 7, the other end of the flow increase line 6 is connected to the primary air duct 3, and the second part is outside the lower secondary air duct 2. Valves are respectively installed behind the 8 auxiliary blowing pipes 4, and a φ76 pipe with a length of 10 cm is installed after the valve. The actual length of the air distribution line 8 is subject to the site. A φ133 mother pipe and 8 φ76 branch pipes are respectively installed on the upper part of the primary air duct 3 of the ignition channel on the left and right sides behind the pulverized coal furnace 1, and are connected to the auxiliary blowing pipe 4 through the air distribution line 8. A metal hose 9 not shorter than 1 meter needs to be installed on the outside of the air distribution line 8 to prevent it from affecting the hot and cold expansion of the unit. A valve body of corresponding caliber is installed at the rear of the metal hose 9 to facilitate operation during operation, and all welds are welded by ordinary electric welding.

[0023] In a preferred embodiment, a bend pipe 13 is provided at the secondary air duct 2 where the auxiliary blowing pipe 4 is installed. The auxiliary blowing pipe 4 extends through the bend pipe 13 to the inside. Compared with welding, it is easier to replace and repair the bend pipe 13 when the auxiliary blowing pipe 4 fails.

[0024] It should be noted that the above embodiments all belong to the same utility model concept, and the description of each embodiment has its own focus. For matters that are not described in detail in some embodiments, reference can be made to the description in other embodiments.

[0025] The above-mentioned embodiments only express the implementation methods of the utility model, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, and these all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.

Claims

1. A blowing device for the outlet of the secondary air duct behind a furnace, comprising a pulverized coal furnace (1), the pulverized coal furnace (1) being equipped with a primary air duct (3) and a secondary air duct (2), a combustion device (12) being arranged at one end of the primary air duct (3) close to the pulverized coal furnace (1), characterized in that: An auxiliary blowing pipe (4) is provided at one end of the secondary air duct (2) close to the air outlet, and the other end of the auxiliary blowing pipe (4) is connected to a fan (5).

2. The blowing-assisting device at the outlet of the lower secondary air duct behind the furnace according to claim 1 is characterized in that: The auxiliary blowing pipe (4) extends to the interior of the secondary air pipe (2); the blowing port of the auxiliary blowing pipe (4) is aligned with the air outlet of the secondary air pipe (2) and is located at the center of the secondary air pipe (2).

3. The blowing-assisting device at the outlet of the lower secondary air duct behind the furnace according to claim 1 is characterized in that: The blowing-assisting pipe (4) is provided with a valve body, and the valve body controls the flow of air in the blowing-assisting pipe (4).

4. The blowing-assisting device at the outlet of the lower secondary air duct behind the furnace according to claim 1 is characterized in that: The auxiliary blowing pipe (4) is provided with an air distribution line (8), the air distribution line (8) is connected to a metal hose (9), and the metal hose (9) is equipped with a valve body.

5. The blowing-assisting device at the outlet of the lower secondary air duct behind the furnace according to claim 4 is characterized in that: The air distribution pipeline (8) is connected to the flow-increasing pipeline (6) via a three-way valve (7), and the other end of the flow-increasing pipeline (6) is in communication with the primary air duct (3).

6. The blowing-assisting device at the outlet of the lower secondary air duct behind the furnace according to claim 1 or 2, characterized in that: The secondary air duct (2) is provided with a bent pipe (13) at the location where the auxiliary blowing pipe (4) is installed, and the auxiliary blowing pipe (4) penetrates the bent pipe (13) and extends to the interior.

7. The blowing-assisting device at the outlet of the lower secondary air duct behind the furnace according to claim 1, characterized in that: An oil distribution air duct (11) is provided on the top of the combustion device (12).

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