Combustion furnace matched with pulverized coal preparation system for outlet low-oxygen-content flue gas

Abstract

The utility model relates to the technical field of pulverized coal preparation, and discloses a pulverized coal preparation system supporting combustion furnace with low-oxygen-content flue gas at an outlet, the pulverized coal preparation system supporting combustion furnace comprises a smoke exhaust cylinder, a flue gas backflow fan, a combustion furnace and a coal mill, a flue gas main body is formed in the smoke exhaust cylinder, and the top end of the combustion furnace is connected with a second valve. According to the utility model, the flow of the smoke main body entering the combustion furnace is adjusted by regulating and controlling the first valve and the smoke backflow fan and the detection value of the flow meter, a heat-insulating layer is not arranged in the flue which is connected from the smoke exhaust cylinder to the flue which is not mixed with the combustion smoke of the combustion furnace, and meanwhile, the heat-insulating layer is arranged in the flue which is mixed with the combustion smoke of the combustion furnace; and the second valve of the flue gas inlet connected with the combustion furnace adjusts the proportion of the flue gas entering the front end and the rear end of the combustion furnace, so that the combustion temperature of the combustion furnace is conveniently controlled, a refractory material in the combustion furnace is protected, stable combustion of the combustion furnace is ensured, and the oxygen content in the combustion flue gas of the combustion furnace is controlled.

Description

Technical Field

[0001] The utility model relates to the technical field of coal powder preparation, in particular to a combustion furnace supporting a coal powder preparation system for exporting low-oxygen-content flue gas. Background Art

[0002] The combustion furnace supporting the coal powder preparation system is used as the drying heat source of the coal powder preparation system. Its characteristics are that the flue gas temperature at the coal mill inlet is low, which is not higher than 90℃ for lignite, not higher than 120℃ for bituminous coal, and not higher than the lowest ignition point of 50℃ for other types of coal. At the same time, the oxygen content of the flue gas at the coal mill inlet is ≤8%. By controlling the flue gas temperature and oxygen content at the coal mill inlet, the coal powder preparation system is prevented from spontaneous combustion and the safe operation of the coal powder preparation system is ensured.

[0003] The existing method of reducing the inlet flue gas temperature of the coal mill is usually to mix a portion of ambient air into the flue gas. The above method has the problem of increased oxygen content in the flue gas. Flue gas with high oxygen content flows in the coal powder preparation system, increasing the possibility of spontaneous combustion of the coal powder preparation system. Utility Model Content

[0004] The utility model aims to provide a combustion furnace supporting a pulverized coal preparation system with an outlet flue gas having a low oxygen content, so as to solve the problem of high oxygen content in the flue gas at the inlet of the coal mill proposed in the above-mentioned background technology.

[0005] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a coal powder preparation system supporting a combustion furnace that exports low-oxygen content flue gas, including a smoke exhaust chimney, a smoke return fan, a combustion furnace, and a coal mill. A smoke main body is formed inside the smoke exhaust chimney, flues are connected on both sides of the smoke return fan and between the combustion furnace and the coal mill, a first valve is installed inside the flue, a flow meter is installed inside the flue, a dehydrator is connected to one side of the flue, a condensate drainer is provided at the bottom end of the dehydrator, and a second valve is connected to the top of the combustion furnace.

[0006] Preferably, the main body of smoke is led out from the inside of the smoke exhaust pipe, and the smoke duct flows between the smoke return fan, the dehydrator, and the combustion furnace.

[0007] Preferably, no insulation layer is provided in the flue before the combustion flue gas of the combustion furnace is mixed, and an insulation layer is provided in the flue after the combustion flue gas of the combustion furnace is mixed.

[0008] Preferably, there is an interface angle between the flue and the smoke exhaust pipe, and the interface angle is preferably an acute angle, followed by a right angle, and then an obtuse angle.

[0009] Preferably, the smoke return fan cooperates with the smoke main body to form flow power, and a motor is installed in the smoke return fan. The motor can be an industrial frequency motor or a variable frequency motor.

[0010] Preferably, the condensate drainer is installed at the low point of the flue, and a water replenishment port and an overflow drain port are provided inside the condensate drainer.

[0011] Preferably, the dehydrator is used in a baffle type, a gravity type, a cyclone type or a combination of the above types, and the second valve is adjusted manually or automatically.

[0012] Preferably, an interface is installed between the combustion furnace and the flue gas body, and the interface is arranged at the front and rear ends of the combustion furnace.

[0013] Compared with the prior art, the utility model has the following beneficial effects: the combustion furnace supporting the pulverized coal preparation system for exporting low-oxygen flue gas improves the flue gas temperature control capability and flow safety;

[0014] (1) The flow rate of the main flue gas entering the combustion furnace is adjusted by regulating the first valve, the flue gas return fan, and the detection value of the flow meter. No insulation layer is set in the flue from the exhaust pipe to the flue before mixing with the combustion flue gas of the combustion furnace, so as to reduce the temperature of the main flue gas entering the combustion furnace. The lower the temperature of the main flue gas, the lower the saturated steam pressure, and the lower the saturated water content in the main flue gas. The free water in the main flue gas is discharged through the condensate drainer and the dehydrator, so as to reduce the influence on the drying effect of the coal powder preparation system. At the same time, an insulation layer is set in the flue after mixing with the combustion flue gas of the combustion furnace to reduce the heat loss of the mixed flue gas entering the coal mill. The second valve of the flue gas inlet connected to the combustion furnace adjusts the ratio of the flue gas entering the front and rear ends of the combustion furnace, so as to control the combustion temperature of the combustion furnace, protect the refractory materials inside the combustion furnace, ensure the stable combustion of the combustion furnace, and control the oxygen content in the combustion flue gas of the combustion furnace;

[0015] (2) The oxygen content in the flue gas drawn out from the smoke exhaust chimney is much lower than that in the ambient air. The flue gas drawn out from the smoke exhaust chimney is returned to the combustion furnace. While ensuring that the drying heat provided to the pulverized coal preparation system remains unchanged, the oxygen content of the flue gas entering the coal mill inlet of the pulverized coal preparation system is greatly reduced. That is, while ensuring the drying effect of the pulverized coal preparation system, the safety performance can also be fully guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the main structure of the utility model;

[0017] Figure 2 It is a partial front view structural schematic diagram of the combustion furnace of the present utility model.

[0018] In the figure: 1. Flue gas main body; 2. Flue duct; 3. Smoke exhaust chimney; 4. First valve; 5. Flow meter; 6. Flue gas return fan; 7. Condensate drainer; 8. Dehydrator; 9. Combustion furnace; 10. Coal mill; 11. Second valve. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0020] See also Figure 1-2 The utility model provides an embodiment: a combustion furnace supporting a pulverized coal preparation system for exporting low-oxygen flue gas, comprising a smoke exhaust chimney 3, a smoke return fan 6, a combustion furnace 9, and a coal mill 10. A smoke main body 1 is formed inside the smoke exhaust chimney 3, flues 2 are connected on both sides of the smoke return fan 6 and between the combustion furnace 9 and the coal mill 10, a first valve 4 is installed inside the flue 2, a flow meter 5 is installed inside the flue 2, a dehydrator 8 is connected to one side of the flue 2, a condensate drainer 7 is provided at the bottom end of the dehydrator 8, and a second valve 11 is connected to the top of the combustion furnace 9.

[0021] The main body of smoke 1 is led out from the inside of the smoke exhaust pipe 3, and the flue 2 flows between the smoke return fan 6, the dehydrator 8, and the combustion furnace 9.

[0022] No insulation layer is provided in the flue 2 before the combustion flue gas of the combustion furnace 9 is mixed, and an insulation layer is provided in the flue 2 after the combustion flue gas of the combustion furnace 9 is mixed.

[0023] There is an interface angle between the flue 2 and the smoke exhaust pipe 3, and the interface angle is preferably an acute angle, followed by a right angle, and then an obtuse angle.

[0024] The smoke return fan 6 cooperates with the smoke main body 1 to form flow power. A motor is installed in the smoke return fan 6, and the motor can be an industrial frequency motor or a variable frequency motor.

[0025] The condensate drainer 7 is installed at the low point of the flue 2. A water replenishment port and an overflow drain port are provided inside the condensate drainer 7. Through the effective water seal height, only the liquid water in the flue 2 is discharged online in real time without smoke escaping.

[0026] The dehydrator 8 is used in a baffle type, a gravity type, a cyclone type or a combination of the above types, and the second valve 11 is adjusted manually or automatically.

[0027] An interface is installed between the combustion furnace 9 and the smoke body 1, and the interface is arranged at the front and rear ends of the combustion furnace 9;

[0028] Further, the flow velocity of the main body of smoke 1 in the flue 2 is 15m / s to 28m / s, and the size of the flue 2 is determined according to the flow rate of the main body of smoke 1;

[0029] The further pressure of the flue gas return fan 6 is 1 to 5 kPa, which is determined according to the system resistance between the main flue gas 1 being led out from the inside of the flue gas exhaust 3 and entering the combustion furnace 9;

[0030] Further, a detection instrument for detecting the pressure and temperature of the main smoke body 1 is installed on the flue 2. Further, a first valve 4 is installed on the flue 2 to control the extraction of the main smoke body 1 from the smoke exhaust pipe 3. It can be a switch type valve or a regulating type valve.

[0031] A further flow meter 5 is used to detect the flow rate of the main body of flue gas 1 entering the combustion furnace 9;

[0032] It should be noted that the outlet flue gas of the combustion furnace 9 is a mixed flue gas of the combustion flue gas of the combustion furnace 9 and the flue gas body 1, and the mixed flue gas is transported to the inlet of the coal mill 10 through the flue 2;

[0033] It should also be noted that, according to needs, the top of the combustion furnace 9 is connected to a second valve 11 , and the second valve 11 can also be installed at a side position of the combustion furnace 9 .

[0034] Working principle: First, the flue 2 is connected from the side of the smoke exhaust pipe 3, the first valve 4 is opened, and the main smoke 1 enters the smoke return fan 6. After the main smoke 1 is pressurized by the smoke return fan 6 to obtain kinetic energy, it enters the dehydrator 8. In the dehydrator 8, the free water and gas of the main smoke 1 are separated. The main smoke 1 at the outlet of the dehydrator 8 enters and mixes with the combustion smoke of the combustion furnace 9, and finally enters the inlet of the coal mill 10 through the flue 2. The smoke inlet connected to the combustion furnace 9 is provided with a second valve 11 for adjusting The ratio of the flue gas entering the front and rear ends of the combustion furnace 9. A flow meter 5 is installed on the flue 2 to detect the flow entering the combustion furnace 9. When the flow of the main flue gas 1 is too large, the operating parameters of the first valve 4 and the flue gas return fan 6 are reduced, and vice versa. Pressure and temperature detection instruments are also installed on the flue 2 to detect the operating values ​​of the main flue gas 1 in real time and provide operating guidance values ​​for the return of the main flue gas 1. A condensate drainer 7 is installed at the low point of the flue 2 to discharge the liquid water in the flue 2 online in real time.

[0035] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

Claims

1. A combustion furnace for a pulverized coal preparation system that exports low-oxygen flue gas, comprising a smoke exhaust pipe (3), a flue gas return fan (6), a combustion furnace (9), and a coal mill (10), characterized in that: A smoke main body (1) is formed inside the smoke exhaust pipe (3), flues (2) are connected to both sides of the smoke return fan (6) and between the combustion furnace (9) and the coal mill (10), a first valve (4) is installed inside the flue (2), a flow meter (5) is installed inside the flue (2), a dehydrator (8) is connected to one side of the flue (2), a condensate drainer (7) is provided at the bottom end of the dehydrator (8), and a second valve (11) is connected to the top of the combustion furnace (9).

2. The combustion furnace for a pulverized coal preparation system for exporting low-oxygen flue gas according to claim 1, characterized in that: The main body of smoke (1) is led out from the inside of the smoke exhaust pipe (3), and the flue (2) flows between the smoke return fan (6), the dehydrator (8), and the combustion furnace (9).

3. The combustion furnace for a pulverized coal preparation system for exporting low-oxygen flue gas according to claim 1, characterized in that: No heat preservation layer is provided in the flue (2) before the combustion flue gas of the combustion furnace (9) is mixed, and a heat preservation layer is provided in the flue (2) after the combustion flue gas of the combustion furnace (9) is mixed.

4. The combustion furnace for a pulverized coal preparation system for exporting low-oxygen flue gas according to claim 1, characterized in that: There is an interface angle between the flue (2) and the smoke exhaust pipe (3), and the interface angle is preferably an acute angle, followed by a right angle, and then an obtuse angle.

5. The combustion furnace for a pulverized coal preparation system for exporting low-oxygen flue gas according to claim 1, characterized in that: The smoke return fan (6) cooperates with the smoke main body (1) to form flow power. A motor is installed in the smoke return fan (6), and the motor can be an industrial frequency motor or a variable frequency motor.

6. The combustion furnace for a pulverized coal preparation system for exporting low-oxygen flue gas according to claim 1, characterized in that: The condensate drainer (7) is installed at the lowest point of the flue (2), and a water replenishment port and an overflow drain port are provided inside the condensate drainer (7).

7. The combustion furnace for a pulverized coal preparation system for exporting low-oxygen flue gas according to claim 1, characterized in that: The dehydrator (8) is used in a baffle type, a gravity type, a cyclone type or a combination of the above types, and the second valve (11) is adjusted manually or automatically.

8. The combustion furnace for a pulverized coal preparation system for exporting low-oxygen flue gas according to claim 1, characterized in that: An interface is installed between the combustion furnace (9) and the smoke body (1), and the interface is arranged at the front and rear ends of the combustion furnace (9).

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