CN201322439Y - Pulverized-coal burnt horizontal-type hot fume generating furnace - Google Patents

Abstract

A horizontal hot flue gas generator for burning coal powder, comprising a front wall (11), a rear wall (12) and a side wall (13), and at least one pulverized coal burner ( 2), each wall is connected to the top (15), and it is characterized in that it also includes at least one air preheater (9) for heating the combustion-supporting air with the hot flue gas produced by the hot flue gas generator, and the air preheater includes Combustion-supporting air inlet (8) and combustion-supporting air outlet (10). The combustion-supporting air coming out from the combustion-supporting air outlet (10) enters the flue gas generator through the pulverized coal burner (2).

Description

A horizontal hot flue gas generator burning coal powder

technical field

The utility model relates to a hot flue gas generator, in particular to a horizontal hot flue gas generator for burning coal powder. The hot flue gas generator is usually used to generate hot flue gas to dry materials, such as low-rank coal wait.

Background technique

Material drying is a process commonly used in many industrial fields such as chemical industry, mining, metallurgy, etc. Usually, hot fluid is used as the heating and drying medium, such as hot flue gas or hot air. At present, the heat source for generating high-temperature gas to heat the drying medium in the relevant process is basically the combustion heat of gas combustion or liquid combustion. The use of gaseous fuel or liquid fuel is due to the shortage and high price of resources, and the cost of generating thermal fluid is relatively high. my country is one of the countries with abundant coal resources in the world, and the coal reserves are far greater than the reserves of oil and natural gas. Therefore, coal-fired hot flue gas generators are often used to generate hot flue gas for material drying, such as using fire bed furnaces or The fluidized bed burns raw coal directly. However, the heat loss of mechanical incomplete combustion and chemical incomplete combustion is relatively large in the combustion process of direct combustion of raw coal, and it is not easy to control. Therefore, there are also hot flue gas generators that use pulverized coal, that is, the fine coal powder that meets the size is sent into the combustion chamber through the pulverized coal burner with the combustion air, and burned in a suspended state, which can increase the amount of pulverized coal particles and air. The contact surface area enhances combustion. This kind of combustion makes the temperature in the furnace higher, the combustion is relatively complete, and the combustion efficiency is higher. However, when using pulverized coal as fuel, the existing pulverized coal-fired thermal flue gas generator mainly has the following problems:

(1) Airflow entrained with pulverized coal directly uses cold air to support combustion. For fuels with relatively low volatile content that are not easily ignited, it is easy to cause difficulty in ignition, unstable combustion, and reduced combustion efficiency. Stable combustion due to oil injection, resulting in an increase in the operating cost of the hot flue gas generator;

(2) Using an external heat source to preheat the combustion-supporting air increases the operating cost of the hot flue gas generator;

(3) Directly adopting cold air as the temperature-regulating air for hot flue gas will result in large exhaust loss, greatly reducing the thermal efficiency of the hot flue gas generator, and at the same time, increasing fuel consumption;

(4) Using cold air as the temperature-regulating wind for hot flue gas will increase the oxygen content in the flue gas, and there are potential safety hazards for materials with poor thermal stability, easy spontaneous combustion, or sensitive to oxygen components;

(5) Most of these pulverized coal-fired hot blast stoves are similar to adiabatic furnaces, and serious slagging phenomenon is common.

Utility model content

The purpose of the utility model is to provide a horizontal hot flue gas generator for burning coal powder, in which the coal powder and air flow can be ignited rapidly when entering the furnace, and the combustion is stable and efficient.

The utility model provides a horizontal hot flue gas generator for burning coal powder, which comprises a front wall, a rear wall and a side wall, and at least one pulverized coal burner for burning coal powder in the furnace, and each wall is connected to the top. , is characterized in that it also includes at least one air preheater for heating the combustion air with the hot flue gas produced by the hot flue gas generator, the air preheater includes a combustion air inlet and a combustion air outlet, and comes out from the combustion air outlet) The combustion air enters the flue gas generator through the pulverized coal burner. According to the further disclosure of the utility model, the pulverized coal burner is a swirl burner, and is arranged on the front wall of the hot flue gas generator.

In addition, a plurality of flue gas nozzles are also provided for receiving at least a part of the flue gas discharged from the dryer and returning to the hot flue gas generator. The plurality of flue gas nozzles may include front wall flue gas nozzles, and these front wall flue gas nozzles are arranged on the front wall of the hot flue gas generator at a position near the intersection line between the front wall and the top of the hot flue gas generator , and are arranged along lines parallel to this intersection. This front wall flue gas nozzle arrangement is to prevent slagging at the top of the furnace inner wall. In order to make the effect of slag prevention better, a slope inclined to the front wall is formed on the rear wall of the hot flue gas generator in the embodiment of the present invention. In addition, the flue gas nozzles also include furnace bottom flue gas nozzles and/or side wall flue gas nozzles.

According to an example of the utility model, it also includes an ash hopper for depositing fly ash and a furnace bottom slag outlet arranged at the flue gas generator. Further, the ash hopper is arranged under the air preheater. In addition, the air preheater is also equipped with a compressed air soot blowing device to better remove fly ash in the flue gas.

The hot flue gas generator of the utility model improves combustion efficiency, reduces flue gas emission loss and fuel consumption, thereby improving the overall thermal efficiency of the hot flue gas generator.

Description of drawings

Below, describe embodiment of the present utility model in detail in conjunction with accompanying drawing, wherein:

Fig. 1 is the side view of horizontal hot flue gas generator of the present utility model;

Fig. 2 is the front view of the hot flue gas generator of Fig. 1;

Fig. 3 is a cross-sectional view of the hot flue gas generator in Fig. 1 along the line A-A.

reference sign

1. Furnace bottom flue gas nozzle

2. Pulverized coal burner

3. Front wall flue gas nozzle

4. Side wall flue gas nozzle

5. Dryer

6. Ash bucket

7. Bottom slag outlet

8. Combustion air inlet

9. Air preheater

10. Combustion air outlet

11. Front wall

12. Back wall

13. Side wall

14. Furnace bottom

15. top

Detailed ways

In order to better illustrate the utility model, the utility model is further illustrated below through specific examples.

Referring now to Fig. 1, an embodiment of the hot flue gas generator of the present invention is shown. The hot flue gas generator is arranged horizontally, the inner wall of the furnace can be laid with corrosion-resistant refractory bricks, and the outer wall is laid with insulating bricks and steel guard plates; the top structure of the hot flue gas generator is arched and supported by a steel shell; the combustion chamber The side wall is provided with a fire viewing port and an accidental slag removal port (not shown), and the top 15 or side wall 13 of the hot flue gas generator can be designed with an explosion-proof door.

Referring to FIG. 1 , the hot flue gas generator of the present invention includes at least one pulverized coal burner 2 . Carried by the primary air, the pulverized coal passes through the pulverized coal burner 2 and enters the hot flue gas generator for combustion. The pulverized coal burner 2 may be a swirl type pulverized coal burner. Each swirl type pulverized coal burner is adjustable by wind. The primary air carries pulverized coal through the primary air duct of the burner. The central pipe is arranged in the primary air duct, and the ignition oil gun is arranged in the central pipe. flow; the secondary air is the swirling flow caused by tangential or axial blades, the angle of the swirling blades is adjustable, and the outlet is designed as a swirl. In the ignition stage, the pulverized coal is ignited with an ignition oil gun, and the oil is cut off after the furnace is preheated. During normal operation, there is no need to inject oil to support combustion. Figure 2 shows that four pulverized coal burners 2 are arranged in pairs on the front wall of the hot flue gas generator, and the swirl direction of the pulverized coal burners 2 on the same row is opposite, and on the same column The swirl direction of the pulverized coal burner 2 is the same. It should be understood that the type, number and arrangement of the pulverized coal burners may vary.

The pulverized coal and combustion-supporting air entering from the burner are burned in the hearth of the hot flue gas generator, and the hot flue gas generated by the combustion will pass through the air preheater 9 to heat the combustion-supporting air after temperature adjustment. The air preheater 9 may be a tubular air preheater. As shown in FIG. 3 , cold air enters the air preheater 9 from the combustion air inlet 8 of the air preheater 9 , and hot flue gas passes through the air preheater 9 to heat the air. In order to obtain the temperature information of the combustion air, temperature measuring points can be respectively set at the inlet 8 and the outlet 10 of the combustion air. The heated combustion-supporting air enters the hot flue gas generator through the pulverized coal burner to support combustion. Usually the heated combustion air will be divided into two streams, one as primary air carrying pulverized coal, and one as secondary air.

The hot flue gas passing through the air preheater 9 is sent out for various purposes, for example, sent to the dryer 5 for drying the material to be dried. At least a part of the flue gas discharged from the dryer 5 can be returned to the hot flue gas generator through the flue gas nozzle. Adjusting the position of the flue gas nozzle and the direction of the draft can be used to prevent slagging in the furnace and/or to adjust the temperature of the flue gas produced by the hot flue gas generator. Figure 2 shows an embodiment of the position of the flue gas nozzles, five front wall flue gas nozzles 3 are arranged on the front wall of the hot flue gas generator, and are located near the intersection line between the top of the hot flue gas generator and the front wall The position is arranged along the parallel line of the intersection line, so that the smoke injected from the five front wall smoke nozzles 3 can be sprayed all the way to the rear wall, thereby forming a gap between the combustion in the furnace and the wall of the furnace roof. The gas barrier layer is formed, thereby effectively preventing the slagging of the wall of the hot flue gas generator roof. As shown in Figure 2, it is more preferable that the rear wall of the hot flue gas generator is sloped towards the front wall, so that the flue gas sprayed to the rear wall is deflected downward at the rear wall and mixed with the hot flue gas generated by combustion Tempering without direct reflection back weakens the effect of the gas barrier and combustion. The flue gas nozzles can be arranged at various suitable positions of the hot flue gas generator. For example, as shown in FIG.

As shown in Figure 1, a slag outlet 7 is provided at the bottom of the furnace to discharge the residue generated by combustion out of the furnace, and an ash hopper 6 can also be provided for depositing fly ash. The ash hopper 6 can preferably be arranged below the air preheater 9 . In addition, a compressed air soot blowing device can also be installed in the air preheater to blow off the dust that affects the heat transfer and exchange, so as to increase the heat exchange effect.

Claims (10)

1. the horizontal hot flue gas producer of a combusting coal fines, comprise front wall (11), back wall (12) and side wall (13), and be used at least one coal burner (2) that coal dust enters the stove internal combustion, each wall is connected with top (15), it is characterized in that, at least one air preheater (9) that also comprises the hot flue gas heating combustion air that produces with hot flue gas producer, described air preheater comprises combustion air inlet (8) and combustion air outlet (10), and the combustion air that comes out from combustion air outlet (10) enters described flue gas producer by coal burner (2).

2. hot flue gas producer according to claim 1 is characterized in that described coal burner (2) is a vortex burner.

3. hot flue gas producer according to claim 1 and 2 is characterized in that, described coal burner (2) is arranged on the front wall (11) of hot flue gas producer.

4. hot flue gas producer according to claim 1 is characterized in that, also comprises a plurality of flue gas spouts, is used for admitting at least a portion flue gas of discharging from drier (5) to turn back to described hot flue gas producer.

5. hot flue gas producer according to claim 4, it is characterized in that, described flue gas spout comprises front wall flue gas spout (3), described front wall flue gas spout (3) is arranged on the front wall (11) of hot flue gas producer, be positioned near front wall (11) position of hot flue gas producer, and arrange along the parallel lines of described intersection with the intersection at top (15).

6. hot flue gas producer according to claim 1 is characterized in that, the back wall (12) of described hot flue gas producer forms the slope to front wall (11) inclination.

7. hot flue gas producer according to claim 4 is characterized in that, described flue gas spout comprises furnace bottom flue gas spout (1) and/or side wall flue gas spout (4).

8. hot flue gas producer according to claim 1 is characterized in that, also comprises ash bucket (6) that is used to deposit flying dust and the hearth deslagging mouth (7) that is arranged on the flue gas producer.

9. hot flue gas producer according to claim 8 is characterized in that described ash bucket (6) is arranged on the below of air preheater.

10. hot flue gas producer according to claim 1 is characterized in that described air preheater (9) is provided with the compressed air soot-blowing device.

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