WO2021128951A1

WO2021128951A1 - Novel coke oven structure and sectional heating combustion method thereof

Info

Publication number: WO2021128951A1
Application number: PCT/CN2020/114457
Authority: WO
Inventors: 李超; 李国志
Original assignee: 中冶焦耐(大连)工程技术有限公司
Priority date: 2019-12-27
Filing date: 2020-09-10
Publication date: 2021-07-01
Also published as: CN110938447A

Abstract

Disclosed are a novel coke oven structure and a sectional heating combustion method thereof. The novel coke oven structure comprises an oven roof, combustion chambers, carbonization chambers, a chutes region, heat storage chambers, and small flues. The combustion chambers are connected to the heat storage chambers via the chutes. Each combustion chamber is composed of a plurality of vertical flue pairs. The top portions of the vertical flues forming each pair are in communication with each other via a spanning hole, the bottom portions thereof are in communication with each other via an exhaust gas circulation hole. The lower portion of each heat storage chamber is provided with small flues. A flame observation hole is provided on the oven roof above each vertical flue. A coal charging and flame guide hole and an ascending pipe hole are provided on the oven roof above each carbonization chamber. A plurality of coal gas outlets and a plurality of air outlets are arranged in each vertical flue along a height direction. The bottom surface of a carbonization chamber is higher than the bottom surface of a combustion chamber corresponding to a chute opening. The invention improves the structure of the vertical flues of the combustion chambers of the coke oven, which achieves combustion processes under multiple low-nitrogen combustion mechanisms, and adopts a novel design in which the bottom surface of a carbonization chamber is higher than the bottom surface of a combustion chamber, which eliminates the risk of green coke generation due to insufficient heat supply at the bottom of the carbonization chambers resulting from sectional combustion.

Description

A new type of coke oven structure and its segmented heating and combustion method

This application claims the priority of a Chinese patent application filed with the Chinese Patent Office on December 27, 2019, the application number is 201911376204.4, and the invention title is "a new type of coke oven structure and its segmented heating and combustion method". The entire content of the application is approved The reference is incorporated in this application.

Technical field

The present invention relates to the technical field of coke ovens, in particular to a novel coke oven structure capable of realizing the generation of low nitrogen oxides and a segmented heating and combustion method thereof.

Background technique

With the continuous development of the overall process technology of the machine-mounted coke oven, the height of the coking chamber of the coke oven has been developed from less than 2.8 meters to 7.65 meters, and the 8.43 meter test furnace of Uhde, Germany has also been put into operation for many years. At present, the development of new coke ovens has approached the limit in the research direction of increasing the height and volume of the coking chamber.

With the increasing demand for environmental protection, the development of coke oven technology has taken a new direction. In the production process of coke ovens, how to effectively reduce the fugitive and organized emissions of smoke and dust has been paid more and more attention, and pollution control from the source has become a new topic in the research and development of coke oven equipment and technology.

At present, the design of the coke oven combustion system is still at the stage of simple segmented combustion and imitating foreign advanced technology. The main problem is how to set the structure of the vertical fire channel, the position of each air outlet section and the flow rate to reduce the generation of nitrogen oxides. It uses the existing mature low-nitrogen combustion technology and non-selective catalytic reduction technology to reduce nitrogen oxide emissions.

In addition, for coke ovens using segmented combustion technology, because it has changed the original coke oven design where the bottom heating capacity is much larger than the top heating method, the bottom surface of the combustion chamber and the bottom surface of the coking chamber corresponding to the chute mouth in the traditional coke oven are both located at The same level, so there is a risk of coke formation in the lower part of the coking chamber of the coke oven.

Summary of the invention

The invention provides a new type of coke oven structure and its segmented heating and combustion method. By improving the structure of the vertical fire channel of the coke oven combustion chamber, the combustion process under a variety of low-nitrogen combustion mechanisms is realized, and the bottom surface of the coking chamber is higher than the combustion chamber. The new design of the bottom surface eliminates the risk of coke formation due to insufficient heat supply at the bottom of the coking chamber due to segmented combustion.

In order to achieve the above objectives, the present invention adopts the following technical solutions to achieve:

A new type of coke oven structure, including furnace roof, combustion chamber, carbonization chamber, chute area, regenerator and small flue; the combustion chamber and the carbonization chamber are arranged alternately, and the combustion chamber is connected to the regenerator through the chute, and the combustion chamber It is composed of multiple double-joint fire passages. The top of the double-joint fire passage is connected through cross holes, and the bottom is connected through exhaust gas circulation holes; the lower part of each regenerator is provided with a small flue to the outside through an exchange switch The flue gas ducts are connected; the furnace roof above each vertical fire channel is equipped with a fire hole; the furnace roof above each carbonization chamber is equipped with coal loading ports/smoke holes and rising pipe holes; the vertical flame channel is provided with multiple sections along the height direction With gas outlet and multi-stage air outlet, the bottom surface of the carbonization chamber is higher than the bottom surface of the combustion chamber corresponding to the ramp mouth.

Among the multi-stage gas outlets and multi-stage air outlets, from bottom to top, the first-stage gas outlet is higher than the first-stage air outlet, and compared with the two, the first-stage gas outlet is far away from the exhaust gas circulation hole; each middle-stage gas outlet It is arranged staggered with the air outlets of each middle section, and the air outlet of the last section is higher than the gas outlet of the last section.

The bottom surface of the carbonization chamber is higher than the upper edge of the exhaust gas circulation hole, but lower than the first-stage gas outlet elevation.

The combustion chamber is surrounded by a combustion chamber furnace wall, and the combustion chamber furnace wall extends obliquely toward the carbonization chamber at the lower part of the corresponding carbonization chamber, so that the cross section of the lower part of the carbonization chamber is an isosceles trapezoid.

The furnace roof above the vertical fire channel is also provided with compensation holes, which are used to pass supplementary waste gas or mixed low partial pressure reducing gas into the vertical fire channel.

The regenerator is provided with a compartment structure, that is, the air regenerator is divided into a plurality of air compartment regenerators along the height direction, and the gas regenerator is divided into a plurality of gas compartment regenerators along the height direction; the first section The gas outlet alone corresponds to one gas compartmentalized regenerator, and the other sections of gas outlets correspond to one or more gas compartmentalized regenerators; the first section of air outlet alone corresponds to an air compartmentalized regenerator, and the remaining sections of air outlets correspond to one to Multiple air compartment regenerators; correspondingly, the small flue is also connected to each air compartment regenerator/gas compartment regenerator along the high-direction compartment as a plurality of small flues or cluster small flues.

A plurality of manual adjustment gates are arranged at the connection between the small flue and the exhaust gas switch.

The main body of the coke oven is built with refractory bricks, and the positions corresponding to the coal charging port/smoke hole, riser hole, fire hole, compensation hole, and chute adopt castable prefabricated blocks, and the coal charging port/smoke hole , Riser pipe hole, fire hole, compensation hole and chute are respectively set in the corresponding castable prefabricated block.

The chute area of the coke oven is provided with a plurality of supplementary heating holes on the front of the coke oven, and the supplementary heating holes are respectively connected with the corresponding gas chute and air chute.

A new type of stepped heating and combustion method of coke oven structure. The amount of gas flowing out of the first stage gas outlet does not exceed 90% of the total gas supply, and the amount of air flowing out of the first stage air outlet does not exceed the total air supply. 90%, the amount of coal gas at each stage of the gas outlet and the amount of air at each stage of the air outlet are controlled according to the excess air coefficient of the updraft deviating from 1, and the amount of gas in the updraft after the last stage of gas outlet is excessive.

Compared with the prior art, the beneficial effects of the present invention are:

1) A more reasonable application method is provided to realize the low nitrogen oxide combustion of the coke oven combustion chamber vertical flue structure. The heating of the coal cake at the bottom of the coking chamber is completed by the joint action of the two furnace walls and the bottom of the coking chamber. The section heating technology disperses and raises the flame in the vertical flame channel. The present invention raises the bottom of the carbonization chamber, which can enhance the heat transfer of the vertical flame channel to the bottom of the carbonization chamber, indirectly increases the heat transfer in the carbonization chamber, and solves the problem of segmented heating coke ovens. , Especially in coke ovens where a section of the gas outlet is not at the bottom of the vertical fire channel, and the bottom of the carbonization chamber is not heated enough and is easy to appear defects;

2) After the bottom surface of the carbonization chamber is increased, the area with exhaust gas circulation holes at the bottom of the combustion chamber can be avoided, making the furnace wall of the combustion chamber more robust and durable; the lower part of the carbonization chamber is an isosceles trapezoid with a wide upper mouth and a narrow lower mouth, making the carbonization chamber structure With higher strength and more wear resistance, it also facilitates heat transfer and accelerates the maturation speed of the bottom of the coke cake;

3) The combination of various low-nitrogen combustion technologies such as exhaust gas circulation, dense and thin combustion, deep low-oxygen combustion, etc. can be realized in a real sense, through the high-directional division of the regenerator, the setting of the end gate of the small flue, and the regenerator grate The configuration of the daughter board can precisely control the distribution of combustible gas and auxiliary gas in the standing fire channel, thus becoming a brand-new coke oven heating system;

4) There is also a compensation hole at the top of the furnace, which can achieve the purpose of controlling the temperature of the furnace top space and non-selective catalytic reduction of nitrogen oxides by passing different temperature and different types of compensation gas. It is used as a compensation means in The design of the coke oven is also brand new;

5) Applying castable prefabricated blocks to the furnace roof, chute area and other places can reduce the vibration and displacement caused by the mechanical rolling of the coke oven and repeated coke pushing operations, and avoid the furnace caused by the cracking between the refractory materials. The internal gas leaks, reducing the fugitive emission of smoke and dust.

Description of the drawings

Fig. 1 is a schematic diagram of the structure of a novel coke oven according to the present invention.

Figure 2 is a schematic diagram of the relative positional relationship between the bottom surface of the carbonization chamber and the bottom surface of the combustion chamber of the present invention.

In the picture: 1. Furnace roof 2. Combustion chamber 3. Inclined area 4. Regenerator 5. Small flue 6. Carbonization chamber 11. Compensation hole 12. Fire hole 13. Coal charging port/smoke hole 21. First section of gas outlet 22. First section of air outlet 23. Exhaust gas circulation hole 24. Middle section of gas outlet 25. Last section of gas outlet 26. Last section of air outlet 27. Crossing holes 28. Combustion chamber furnace wall 31. Corresponding to the ramp opening The bottom surface of the combustion chamber 32. The bottom surface of the carbonization chamber 33. The ramp 41. Air compartment regenerator/gas compartment regenerator 51. Multiple small flues

Detailed ways

The specific embodiments of the present invention will be further described below in conjunction with the accompanying drawings:

As shown in Figure 1, the novel coke oven structure of the present invention includes a furnace roof 1, a combustion chamber 2, a carbonization chamber, a chute area 3, a regenerator 4 and a small flue 5; a combustion chamber 2 and a carbonization chamber 6-phase arrangement, the combustion chamber 2 is connected to the regenerator 4 through the chute of the chute area 3. The combustion chamber 2 is composed of multiple double-joint fire passages, and the top of the double-joint fire passage passes through the cross hole 27 The bottom of each regenerator 4 is connected through the exhaust gas circulation hole 23; the lower part of each regenerator 4 is provided with a small flue 5 connected to the external flue gas channel through an exchange switch; the top of each vertical fire channel is provided with a fire hole 12; The furnace roof above the carbonization chamber 6 is equipped with coal loading/smoke holes 13 and rising pipe holes; the vertical fire channel is provided with multi-section gas outlets and multi-section air outlets along the high direction, and the bottom surface 32 of the carbonization chamber is higher than the combustion corresponding to the chute opening. The bottom surface of the chamber 31 (as shown in Figure 2).

Among the multi-stage gas outlets and multi-stage air outlets, from bottom to top, the first-stage gas outlet 21 is higher than the first-stage air outlet 22, and compared with the two, the first-stage gas outlet 21 is far away from the exhaust gas circulation hole 23; each The gas outlet 24 of the middle section is staggered with the air outlets of each middle section, and the air outlet 26 of the last section is higher than the gas outlet 25 of the last section.

The bottom surface 32 of the carbonization chamber is higher than the upper edge of the exhaust gas circulation hole 23, but lower than the level of the first-stage gas outlet 21.

The combustion chamber 2 is surrounded by a combustion chamber furnace wall 28, and the combustion chamber furnace wall 28 extends obliquely into the carbonization chamber 6 at the lower part of the corresponding carbonization chamber 6, so that the cross section of the lower part of the carbonization chamber 6 is an isosceles trapezoid.

The furnace roof 1 above the vertical fire channel is also provided with a compensation hole 11 for passing supplementary waste gas or mixed low partial pressure reducing gas into the vertical fire channel.

The regenerator 4 is provided with a grid structure. The grid structure is not only the regenerator compartment along the horizontal direction of the combustion chamber and corresponds to a pair or several opposite fire channels on it, but also can be along the height of the regenerator 4 To the partition wall, the regenerator 4 is arranged side by side and divided into cells, and each small cell can be further subdivided according to the needs of multi-stage heating. The first section of gas outlet 21 corresponds to a single gas compartmentalized regenerator 41, so that the gas flowing through the compartment is discharged from one section of gas outlet 21, and the remaining sections of gas outlets correspond to one or more gas compartmentalized regenerators. Each compartment regenerator can be subdivided into two parts to communicate with the other sections of the outlet; the multi-stage air outlet is similar to the compartment regenerator, the first section of the air outlet 22 is connected to a single air compartment regenerator Correspondingly, the other sections of air outlets correspond to one or more air compartmentalized regenerators, and each compartmentalized regenerator can be subdivided into two parts to communicate with other sections of outlets; accordingly, the small flue 5 is also arranged side by side The compartments are connected to each air compartment regenerator/gas compartment regenerator 41 as a plurality of small flues 51 or cluster small flues.

The connection between the small flue 5 and the exhaust gas switch is provided with multiple manual adjustment gates, which cooperate with the adjustment function of the regenerator grate plate, and can appropriately adjust the gas/air flowing through each compartment of the heat storage according to the type of heating gas Or the flow of exhaust gas, so as to adjust the high-direction heating of the combustion chamber.

The main body of the coke oven is built with refractory bricks, and the positions corresponding to the coal loading port/smoke hole 13, rising pipe hole, fire hole 12, compensation hole 11, and chute 33 are made of castable prefabricated blocks, and the coal loading port /The smoke guide hole 13, the rising pipe hole, the fire hole 12, the compensation hole 11, and the chute 33 are respectively arranged in the corresponding castable prefabricated block.

The chute zone 1 of the coke oven is provided with a plurality of supplementary heating holes on the front of the coke oven, and the supplementary heating holes are respectively connected with the corresponding gas chute and air chute.

A new type of coke oven structure segmented heating and combustion method, the amount of gas flowing out of the first stage gas outlet 21 does not exceed 90% of the total gas supply, and the amount of air flowing out of the first stage air outlet 22 does not exceed the total air supply 90% of the gas volume, the gas volume at each stage of the gas outlet and the air volume at each stage of the air outlet are controlled according to the excess air coefficient of the updraft deviating from 1, and the amount of gas in the updraft after the last stage of gas outlet 25 is excessive.

The novel coke oven structure of the present invention adopts a new chute zone structure in which the elevation of the bottom 32 of the coking chamber is higher than the elevation of the bottom 31 of the combustion chamber corresponding to the chute opening, and the first section of the gas outlet 21 at the bottom of the combustion chamber 2 is higher than the first Sectional heating structure of section air outlet 22.

In addition to the fire hole 12 on the furnace roof 1, there is also a compensation hole 11 above each vertical fire channel. The compensation hole 11 can supplement the exhaust gas of the combustion chamber 2 through the external pipeline of the coke oven or the low partial pressure after mixing Reduction gas operation. This operation can be used to reduce the temperature of the exhaust gas in the combustion chamber 2 or to supplement the heating of the exhaust gas in the combustion chamber 2 to achieve the purpose of adjusting the temperature of the head space of the carbonization chamber.

The vertical fire channel in the combustion chamber 2 adopts the structure of simultaneous segmented heating of gas and air, wherein the first section of gas outlet 21 is higher than the first section of air outlet 22 and the relative position is far from the exhaust gas circulation hole 23, and the middle section of the gas outlet 24 The position is staggered with the positions of the air outlets of each middle section, and the air outlet 26 of the last section is the highest. This ensures that the air at the bottom of the standing fire channel first passes through the combustion-supporting gas diluted by the exhaust gas circulation, and then burns with the gas. After the air is first diluted, the partial pressure of oxygen in the air can be significantly reduced, thereby reducing the intensity of combustion, and inhibiting the combustion process. The nitrogen oxides are generated. The updraft after one stage of combustion is diluted by the gas or air supplied by multiple stages, thereby realizing deviated combustion. Control the excess amount of gas in the updraft after the gas outlet in the last stage of the combustion process. Moreover, the reducing atmosphere of the high-temperature exhaust gas can be used to partially reduce the generated NOx to N2, thereby reducing the production of NOx during the combustion process.

The chute area 3 corresponding to the front of the coke oven can be provided with supplementary heating holes connected to the gas chute and the air chute for supplementary heating of the burner flame, thereby increasing the temperature of the burner flame.

The above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited to this. Anyone familiar with the technical field within the technical scope disclosed by the present invention, according to the technical solution of the present invention The equivalent replacement or change of the inventive concept thereof shall all fall within the protection scope of the present invention.

Claims

A new type of coke oven structure, including furnace roof, combustion chamber, carbonization chamber, chute area, regenerator and small flue; the combustion chamber and the carbonization chamber are arranged alternately, and the combustion chamber is connected to the regenerator through the chute, and the combustion chamber It includes a vertical fire channel, which is characterized in that multiple gas outlets and multiple air outlets are arranged in the vertical fire channel along a high direction, and the bottom surface of the carbonization chamber is higher than the bottom surface of the combustion chamber corresponding to the chute mouth.
A new type of coke oven structure according to claim 1, characterized in that, among the multi-stage gas outlets and multi-stage air outlets, from bottom to top, the first-stage gas outlet is higher than the first-stage air outlet, and both In comparison, the gas outlet of the first section is far away from the exhaust gas circulation hole; the gas outlets of each middle section are staggered with the air outlets of each middle section, and the air outlet of the last section is higher than the gas outlet of the last section.
A new type of coke oven structure according to claim 1, wherein the bottom surface of the coking chamber is higher than the upper edge of the exhaust gas circulation hole, but lower than the first stage gas outlet elevation.
The new type of coke oven structure according to claim 1, wherein the combustion chamber is surrounded by a furnace wall of the combustion chamber, and the furnace wall of the combustion chamber extends obliquely toward the carbonization chamber at the lower part of the corresponding carbonization chamber, so that the carbonization chamber The lower cross section is an isosceles trapezoid.
A new type of coke oven structure according to claim 1, characterized in that, the furnace roof above the vertical fire channel is also provided with a compensation hole, which is used to pass supplementary waste gas or mixed low-grade gas into the vertical fire channel. Pressure reduction gas.
A new type of coke oven structure according to claim 1, characterized in that the regenerator is provided with a grid structure; the first section of gas outlet alone corresponds to a gas subdivision regenerator, and the other sections of gas outlets are connected with each other. One or more gas compartmentalized regenerators correspond; the first section of air outlets corresponds to an air compartmentalized regenerator alone, and the remaining sections of air outlets correspond to one or more air compartmentalized regenerators.
A new type of coke oven structure according to claim 6, wherein the air regenerator is divided into a plurality of air compartment regenerators along the height direction, and the gas regenerator is divided into a plurality of air regenerators along the height direction. A gas compartment regenerator.
A new type of coke oven structure according to claim 6, characterized in that the small flue is divided into multiple small flues or cluster small flues along the height direction or horizontally, and is separated from each air regenerator/gas The compartments are connected to the regenerator.
A new type of coke oven structure according to claim 1, wherein a plurality of manual adjustment gates are provided at the connection between the small flue and the exhaust gas shutter.
A new type of coke oven structure according to claim 1, characterized in that, the main body of the coke oven is built with refractory bricks, and the coal charging port/smoke hole, riser hole, fire hole, and compensation hole are correspondingly provided. , The position of the ramp is made of castable prefabricated blocks, and the coal inlet/smoke hole, riser hole, fire hole, compensation hole, and ramp are respectively set in the corresponding castable prefabricated blocks.
A new type of coke oven structure according to claim 1, wherein the chute area of the coke oven is provided with a plurality of supplementary heating holes on the front of the coke oven, and the supplementary heating holes are respectively connected to the corresponding gas chute and air inclined Roads are connected.
A new type of coke oven structure according to any one of claims 1-11, characterized in that, the combustion chamber is composed of a plurality of double-joint fire channels, and the top of the double-joint fire channel is formed by crossing over The bottom of each regenerator is connected with the exhaust gas circulation hole; the lower part of each regenerator is connected with the external flue gas channel through the exchange switch; the furnace roof above each vertical fire channel is equipped with a fire hole; each carbonization chamber The upper furnace roof is equipped with coal loading ports/smoke holes and rising pipe holes.
The segmented heating and combustion method based on a new type of coke oven structure according to any one of claims 1-11, characterized in that the amount of gas flowing out of the gas outlet of the first stage does not exceed 90% of the total gas supply, from the first The amount of air flowing out of one section of the air outlet does not exceed 90% of the total air supply. After that, the amount of gas at each section of the gas outlet and the amount of air at each section of the air outlet are controlled according to the excess air coefficient of the updraft deviating from 1, and finally There is an excess of gas in the updraft after a section of gas outlet.