CN204829875U - Two furnace fire burning furnace - Google Patents

Abstract

The utility model discloses a double-hearth combustion furnace, which comprises a combustion main furnace and a combustion auxiliary furnace which are connected through a flue pipe. The auxiliary furnace is connected to the flue gas waste heat recovery chamber with a chimney on the top through the flue. The flue gas waste heat recovery chamber is equipped with a flue gas waste heat recovery device, and the inside of the flue gas waste heat recovery device is filled with circulating working medium water; the main furnace, auxiliary furnace and flue gas The position of the waste heat recovery chamber is raised in turn, and the bottom of the main combustion chamber and the auxiliary combustion chamber are respectively provided with the air inlet of the main combustion chamber and the air inlet of the auxiliary combustion chamber, which are directly opposite to the air inlet grid in the combustion furnace, and the air inlet of the main combustion chamber and the combustion chamber. An air regulating valve for controlling the air intake of the combustion main furnace and the combustion auxiliary furnace is installed on the air inlet of the auxiliary furnace. The utility model improves the combustion efficiency, reduces the fuel consumption and suppresses the generation of _NOx .

Description

A double hearth combustion furnace

technical field

The utility model relates to the field of fuel combustion, in particular to a double-hearth combustion furnace.

Background technique

A large part of my country's air pollution comes from the pollutants produced by coal combustion. At present, a large number of scattered residents in my country use traditional coal-fired boilers. However, in recent years, my country has faced increasing environmental pressure. Strict restrictions have been made, and some even prohibit the burning of anthracite. The only alternatives are clean fuels with higher prices such as natural gas. Therefore, it is urgent to find a fuel that is cheap, efficient and low-pollution. Semi-coke (semi-coke) is the product of low or no caking, high volatile coal dry distillation at medium and low temperature. Yulin City is one of the main semi-coke producing areas in my country, which is characterized by low phosphorus, low sulfur, low ash, high calorific value and moderate price. Therefore, semi-coke can be used as a civil fuel in some cities with stricter environmental protection requirements.

However, the traditional equipment burning semi-coke will have the following problems: 1. When the air is sufficient and excessive and the air coefficient is large, the combustion speed is fast, the flue gas stays in the furnace for a short time, and the boiler consumes a large amount of coal, which is easy to burn. Pollutant _NOx is generated. 2. When the amount of fuel is sufficient and excessive and the air coefficient is small, incomplete combustion of C and CO will be generated, so the combustion efficiency of fuel is low and there are potential safety hazards. 3. The flame of semi-coke combustion is relatively short, and the combustion intensity of traditional boiler combustion is not high.

Utility model content

The purpose of this utility model is to solve the problems in the above-mentioned prior art, to provide a boiler that can reduce fuel consumption, improve combustion efficiency, solve the problems of short combustion flame and low combustion intensity, and increase the temperature of high-temperature flue gas in the furnace. A double-hearth combustion furnace that reduces the incompletely combusted C and CO and suppresses the formation of NO _X within the residence time.

In order to achieve the above object, the technical scheme adopted by the utility model double hearth combustion furnace is:

Including the combustion main furnace and the combustion auxiliary furnace connected by the flue pipe, the combustion main furnace and the combustion auxiliary furnace are respectively installed inside the combustion main furnace grate and the combustion auxiliary furnace grate, and the combustion auxiliary furnace is connected to the flue gas of the chimney at the top through the flue Waste heat recovery chamber, flue gas waste heat recovery chamber is equipped with a flue gas waste heat recovery device, and the inside of the flue gas waste heat recovery device is filled with circulating water; The bottom of the furnace and the combustion auxiliary furnace are respectively provided with the air inlet of the main combustion furnace and the air inlet of the auxiliary combustion furnace, which are directly opposite to the air inlet grille in the combustion furnace. And the air regulating valve for the air intake of the combustion auxiliary furnace.

The combustion main furnace includes an upper and lower part of the furnace separated by a grate of the main combustion furnace. The upper and lower parts of the furnace are conical structures and the bottom surfaces of the two are connected.

The auxiliary combustion hearth includes an upper and lower part of the hearth separated by a grate of the auxiliary combustion hearth. Both the upper and lower parts of the hearth are conical structures and the top surfaces of the two parts are connected.

The tops of the main combustion chamber and the auxiliary combustion chamber are respectively equipped with a fire sealing ring for the main combustion chamber and a fire sealing ring for the auxiliary combustion chamber.

The lower part of the air inlet grid is a cold ash hopper.

The bottom of the flue gas waste heat recovery chamber is connected with the combustion auxiliary furnace, and the flue gas waste heat recovery device is arranged on the top of the flue gas waste heat recovery chamber.

The bottom of the flue gas waste heat recovery chamber and the wall of the intake flue gas waste heat recovery chamber facing the flue are inclined at 40°.

A dust scraper is installed on the flue gas waste heat recovery device.

Assuming that the areas of the combustion main furnace grate and the combustion auxiliary furnace grate are A ₁ and A ₂ respectively, and the areas of the combustion main furnace air inlet and the combustion auxiliary furnace air inlet are S ₁ and S ₂ respectively, then S ₁ /S ₂ = 9A ₁ /(1A ₁ +10A ₂ ).

The heat exchange tubes of the flue gas waste heat recovery device are arranged in a staggered or parallel arrangement.

Compared with the prior art, the double-hearth combustion furnace of the utility model adds combustion auxiliary furnaces, the fuel of the combustion auxiliary furnaces is less, and the excess air coefficient is larger, which can further completely burn the C and CO that have not been completely burned in the combustion main furnace, and improve Improve the combustion efficiency of the combustion furnace and reduce safety hazards. The air inlet of the combustion main furnace and the air inlet of the combustion auxiliary furnace are installed with an air regulating valve for controlling the air intake of the combustion main furnace and the combustion auxiliary furnace. Through the air regulating valve, a large amount of fuel in the combustion main furnace is subjected to oxygen-deficient combustion, and the combustion main furnace is formed. The reducing combustion area is beneficial to suppress the generation of NO _X , and at the same time, it can slow down the combustion rate of the main furnace, increase the residence time of fuel in the furnace, and reduce the fuel consumption of the boiler. The traditional combustion furnace is a single furnace. When lower combustion intensity is required, the ventilation rate can only be reduced. However, if the ventilation rate is reduced, the combustion will be insufficient, the combustion efficiency will be reduced, and the fuel consumption will increase. At the same time, a large amount of C and CO will be generated. The flue gas is discharged, and when a higher combustion intensity is required, it can only be increased by increasing the ventilation rate, but the increase in the ventilation rate and the increase in the average temperature of the combustion will increase the _NOx in the combustion products, and the residence time of the fuel in the furnace will increase. Decrease, so that the heat utilization efficiency of the fuel after combustion decreases, and the fuel consumption increases. The height of the combustion main furnace of the double furnace combustion furnace of the utility model is lower than that of the secondary combustion furnace, which can solve the problems of short combustion flame and low combustion intensity of blue charcoal. When a high-intensity combustion effect or raw coal is required, the air inlet of the combustion auxiliary furnace is closed through the air regulating valve, and then the air regulating valve is taken out to crack the combined working state, and independently control the combustion condition of the main combustion furnace. The double hearth combustion furnace of the utility model is especially suitable for burning blue charcoal (semi-coke) for civil use.

Further, the combustion main hearth of the dual-hearth combustion furnace of the present invention includes two upper and lower parts of the furnace separated by the main combustion furnace grate. The backflow of hot flue gas and the heat radiation of the furnace wall play a role in stabilizing the combustion of fuel.

Further, the auxiliary combustion furnace of the double-hearth combustion furnace of the utility model includes two upper and lower parts of the furnace separated by the auxiliary combustion grate. The upper and lower parts of the furnace are conical structures and the two top surfaces are connected. The conical structure is conducive to prolonging the residence time of fuel in the auxiliary combustion chamber to ensure full combustion.

Description of drawings

The overall structure schematic diagram of Fig. 1 the utility model;

The structural representation of Fig. 2 utility model furnace;

Fig. 3 is a structural schematic diagram of the flue gas waste heat recovery chamber of the utility model;

Fig. 4 is the structural representation of the dust-scraping board of the present utility model;

In the attached drawings: 1- combustion main furnace; 2- combustion auxiliary furnace; 3- combustion main furnace grate; 4- combustion auxiliary furnace grate; 5- smoke pipe; 6- flue; 7- smoke waste heat recovery chamber ;8-flue gas waste heat recovery device; 9-ash scraper; 10-air intake grid; 11-cold ash hopper; 12-air control valve; 13-air inlet of combustion main furnace; 15-Fire sealing ring for main furnace; 16-Fire sealing ring for auxiliary furnace.

Detailed ways

Below in conjunction with accompanying drawing, the utility model is described in further detail.

Referring to Figures 1-4, the utility model double-hearth combustion furnace structurally includes a combustion main furnace 1 and a combustion auxiliary furnace 2 connected through a throat pipe 5, and the combustion main furnace 1 and the combustion auxiliary furnace 2 are respectively installed inside the combustion main furnace The grate 3 and the combustion auxiliary furnace grate 4, the combustion main furnace 1 includes the upper and lower parts of the furnace separated by the combustion main furnace grate 3, the upper and lower parts of the furnace are conical structures and the bottom surfaces of the two are connected, and the combustion auxiliary furnace 2 It includes the upper and lower parts of the furnace separated by the auxiliary combustion furnace grate 4. The upper and lower parts of the furnace are both conical structures and the top surfaces of the two are connected. The combustion main furnace 1 and the combustion auxiliary furnace 2 tops are respectively equipped with a combustion main furnace fire sealing ring 15 and a combustion auxiliary furnace fire sealing ring 16 . The bottom of the combustion auxiliary furnace 2 is connected to the flue gas waste heat recovery chamber 7 through the flue 6, the flue gas waste heat recovery chamber 7 is provided with a flue gas waste heat recovery device 8, and the flue gas waste heat recovery device 8 is arranged on the top of the flue gas waste heat recovery chamber 7, A dust scraper 9 is installed on the flue gas waste heat recovery device 8 . The flue gas waste heat recovery device 8 is filled with circulating working medium water, and a chimney is opened on the top of the flue gas waste heat recovery chamber 7 . The positions of the combustion main furnace 1, the combustion auxiliary furnace 2 and the flue gas waste heat recovery chamber 7 are sequentially raised, and the bottom of the flue gas waste heat recovery chamber 7 and the wall surface of the flue gas waste heat recovery chamber facing the flue 6 are inclined at 40°. The bottom of the combustion main furnace 1 and the combustion auxiliary furnace 2 are respectively provided with a combustion main furnace air inlet 13 and a combustion auxiliary furnace air inlet 14 facing the air inlet grid 10 in the combustion furnace, and the lower part of the air inlet grid 10 is a cold ash hopper 11 .

The soot accumulated on the flue gas waste heat recovery device 8 of the utility model is removed by the ash scraper 9, and the burned ash falls into the cold ash hopper 11 at the bottom of the boiler, and the flue 6 is in a gradually expanding structure. An air regulating valve 12 for controlling the air intake of the combustion main furnace 1 and the combustion auxiliary furnace 2 is also installed on the combustion main furnace air inlet 13 and the combustion auxiliary furnace air inlet 14 . The heat exchange tubes of the flue gas waste heat recovery device 8 are arranged in a staggered or parallel arrangement, and the plane height of the fire sealing ring 15 of the combustion main furnace is lower than that of the fire sealing ring 16 of the combustion auxiliary furnace. If it is assumed that the areas of the combustion main furnace grate 3 and the combustion auxiliary furnace grate 4 are A ₁ and A ₂ respectively, and the areas of the combustion main furnace air inlet 13 and the combustion auxiliary furnace air inlet 14 are S ₁ and S ₂ respectively, then S ₁ /S ₂ =9A ₁ /(1A ₁ +10A ₂ ).

The fuel combustion method of the double hearth combustion furnace of the present utility model comprises the following steps:

Step 1, respectively ignite the fuel in the combustion main furnace 1 and the combustion auxiliary furnace 2, and add the blue carbon (semi-coke) in the combustion main furnace 1 and the combustion auxiliary furnace 2 to the position of the smoke throat pipe 5;

Step 2. When the fuel reaches the ignition point, reduce the air intake of the combustion main furnace 1 to make the combustion main furnace 1 under-oxygen combustion, and increase the air intake of the combustion auxiliary furnace 2 to make the combustion auxiliary furnace 2 overoxygen Combustion; the flue gas generated by the combustion main furnace 1 reaches the combustion auxiliary furnace 2 through the flue pipe 5, so that the incompletely burned C and CO are fully burned;

Step 3: The flue gas generated by the combustion auxiliary furnace 2 enters the flue gas waste heat recovery chamber 7 through the flue 6, and performs heat exchange and cooling with the working medium water in the flue gas waste heat recovery device 8 in the flue gas waste heat recovery chamber 7, and finally passes through The chimney goes out.

The advantage of analyzing the double hearth combustion furnace of the present utility model is embodied in the following aspects:

1. The combustion auxiliary furnace 2 has less fuel and a larger excess air coefficient, which can further completely burn the incompletely burned C and CO in the combustion main furnace 1, improve combustion efficiency and reduce safety hazards; 2. Combustion in the main furnace 1 The amount of fuel is large, and what is carried out is oxygen deficient combustion, which makes the formation of reducing combustion zone, which is beneficial to suppress the generation of _NOx ; 3, the plane of the main furnace fire sealing ring 15 is lower than the plane of the combustion auxiliary furnace fire sealing ring 16 H, It can solve the problem of short burning flame of semi-coke and low combustion intensity; 4. The furnace wall of the combustion main furnace 1 is connected by the bottom surface of the upper and lower conical structures. This structure is conducive to the return of hot flue gas and the heat radiation of the furnace wall , to play the role of stable combustion of fuel; 5. The furnace wall of the combustion auxiliary furnace 2 is connected by the top surface of the upper and lower parts of the conical structure. This structure is conducive to prolonging the residence time of the fuel in the combustion auxiliary furnace to ensure sufficient combustion. 6. When a high-intensity combustion effect is required or when raw coal is burned, the air control valve 12 can be used to close the air inlet 14 of the combustion auxiliary furnace, and then the air control valve 12 is drawn out to crack the combined working state, and then separately control the combustion working condition of the main combustion furnace 1 .

Claims (10)

1. a twin furnace combustion furnace, it is characterized in that: comprise the burning main furnace chamber (1) and burning secondary-furnace (2) that are connected by uptake tube (5), install combustion main furnace chamber fire grate (3) and burning secondary-furnace fire grate (4) respectively of burning main furnace chamber (1) and burning secondary-furnace (2) inside, burning secondary-furnace (2) connects by flue (6) the flue gas waste heat recovery room (7) that chimney is offered at top, flue gas waste heat recoverer (8) is established in flue gas waste heat recovery room (7), cycle fluid water is filled in flue gas waste heat recoverer (8) inside, burning main furnace chamber (1), the position of burning secondary-furnace (2) and flue gas waste heat recovery room (7) raises successively, and burning main furnace chamber (1) offers the burning main furnace chamber air inlet (13) just right with air intake grid in combustion furnace (10) and the secondary-furnace air inlet (14) that burns respectively with the bottom of burning secondary-furnace (2), burn main furnace chamber air inlet (13) and burning secondary-furnace air inlet (14) are provided with the air control valve (12) for control combustion main furnace chamber (1) and burning secondary-furnace (2) intake.

2. twin furnace combustion furnace according to claim 1, it is characterized in that: described burning main furnace chamber (1) comprises the burner hearth of two parts up and down separated by burning main furnace chamber fire grate (3), and upper and lower two parts burner hearth is pyramidal structure and the two bottom surface connects.

3. twin furnace combustion furnace according to claim 1, it is characterized in that: described burning secondary-furnace (2) comprises the burner hearth of two parts up and down separated by burning secondary-furnace fire grate (4), and upper and lower two parts burner hearth is pyramidal structure and the two end face connects.

4. the twin furnace combustion furnace according to claim 1 or 2 or 3, is characterized in that: install combustion main furnace chamber fire-sealing ring (15) and burning secondary-furnace fire-sealing ring (16) respectively of described burning main furnace chamber (1) and burning secondary-furnace (2) top.

5. twin furnace combustion furnace according to claim 1, is characterized in that: air intake grid (10) bottom is cold grey slag bucket (11).

6. twin furnace combustion furnace according to claim 1, it is characterized in that: described bottom, flue gas waste heat recovery room (7) is connected with burning secondary-furnace (2), and flue gas waste heat recoverer (8) is arranged on the top of flue gas waste heat recovery room (7).

7. the twin furnace combustion furnace according to claim 1 or 6, is characterized in that: what bottom, described flue gas waste heat recovery room (7) and flue (6) were just right enter, and flue gas waste heat recovery locular wall face is 40 ° is obliquely installed.

8. the twin furnace combustion furnace according to claim 1 or 6, is characterized in that: described flue gas waste heat recoverer (8) is provided with and scrapes hawk (9).

9. twin furnace combustion furnace according to claim 1, is characterized in that: suppose that the area of burning main furnace chamber fire grate (3) and burning secondary-furnace fire grate (4) is respectively A ₁and A ₂, the area of burning main furnace chamber air inlet (13) and burning secondary-furnace air inlet (14) is respectively S ₁and S ₂, then S ₁/ S ₂=9A ₁/ (1A ₁+ 10A ₂).

10. twin furnace combustion furnace according to claim 1, is characterized in that: the heat exchanger tube of described flue gas waste heat recoverer (8) adopts stagger arrangement or in-line arrangement.