CN101694354A - Combustion settling chamber of electric stove fume - Google Patents

Abstract

The invention belongs to the technical field of separation and relates to a combustion settling chamber of electric stove fume. The combustion settling chamber has the functions of removing dust of fume, storing heat, promoting the complete combustion of CO and the like. The adopted settling chamber comprises a fume inlet, an air inlet and a fume outlet and is characterized by arranging a heat storage wall in a combustion chamber. The settling chamber can act on the electric stove fume in removing dust, storing heat and promoting the complete combustion of CO, is beneficial to the sensible heat recovery of electric stove fume, is a significant technology in the recovery of waste heat and emission reduction of smoke dust and CO for an electric steel plant, and has higher economic and social benefits, as well as stronger popularizing value.

Description

An electric furnace flue gas combustion settling chamber

technical field

The invention belongs to the technical field of separation, and relates to an electric furnace flue gas combustion settling chamber. The combustion settling chamber has the functions of flue gas dust removal, heat storage, and promotion of CO burnout.

Background technique

A large amount of flue gas is produced in the process of electric furnace steelmaking. Affected by the steelmaking process, the flow rate, composition and temperature of electric furnace flue gas fluctuate with time during the steelmaking cycle. In order to cool the flue gas produced by electric furnace steelmaking, water-cooled flue is usually used for cooling, which consumes a lot of water and electric energy. In order to recover the sensible heat of the electric furnace flue gas, vaporization cooling can also be used to generate steam. Due to the volatility of the electric furnace flue gas, it is difficult to set up the vaporization cooling system.

The dust content of electric furnace flue gas is relatively large, and it has the characteristics of light, fine, large dispersion and poor fluidity, so it is easy to stick to the heat exchange surface of the vaporization cooling system. At present, the combustion and settling chamber usually used adopts the method of increasing the flow area and reducing the flow rate of the flue gas to settle the smoke and dust. The combustion and settling chamber used in the current project is usually a simple cuboid structure, and the interior is a cuboid space. When the smoke flows through the combustion and settling chamber Because the flow channel area increases, the flow velocity decreases, and large particles of smoke are deposited. The dust removal effect of the traditional combustion settling chamber is poor, especially for fine particles with strong cohesiveness. The temperature of the combustion settling chamber changes drastically with the smelting cycle of the electric furnace.

Electric furnace flue gas contains a small amount of CO (usually within 10%). Low concentration of CO has no recovery value, but if it cannot be effectively burned, it may cause an explosion, and the released CO will also cause pollution. The combustion characteristics of CO are affected by factors such as temperature, oxygen concentration, and residence time. The combustion and settling chambers commonly used at present do not consider the burnout of CO from the perspective of chemical kinetics, and do not take measures from the reaction temperature, the mixing of CO and air, etc. Measures are taken to reduce the CO concentration, resulting in a higher CO concentration when the electric furnace flue gas is discharged.

Contents of the invention

The object of the present invention is to overcome the deficiencies of the prior art and provide an electric furnace flue gas combustion settling chamber. The settling chamber has the functions of flue gas dust removal, heat storage and CO burnout promotion, which is beneficial to the waste heat recovery of electric furnace flue gas.

Main solution of the present invention is realized like this:

The flue gas combustion settling chamber of an electric furnace adopted in the present invention includes a flue gas inlet, an air inlet and a smoke exhaust port, and is characterized in that a heat storage wall is arranged in the combustion chamber.

The water-cooled elbow and water-cooled sliding sleeve of the electric furnace cover are connected with the flue gas inlet. During electric furnace steelmaking, the electric furnace flue gas is introduced into the combustion and settling chamber through the flue gas inlet. One or more layers of heat storage walls are set in the combustion chamber, and the heat storage walls are composed of heat storage materials. When the temperature of the electric furnace flue gas is high, the electric furnace flue gas will be heated when it flows through the heat storage wall, and the temperature of the electric furnace flue gas will decrease; With the fluctuation of the flue gas temperature of the electric furnace, when the flue gas temperature of the electric furnace is low, the flue gas of the electric furnace is heated by the heat storage wall when it flows through the heat storage wall, and the temperature rises. Due to the heat storage effect of the heat storage wall, the temperature of the electric furnace flue gas entering the vaporization cooling system can be adjusted.

In order to reduce the resistance when the electric furnace flue gas flows through the heat storage wall, the heat storage wall is made of heat storage bricks, and flue gas channels are left between the heat storage bricks. Granule beds can also be arranged on the heat storage wall. The particles in the particle bed are made of heat storage materials. The particles not only play the role of heat storage, but also can filter and remove dust, reducing the dust content of the electric furnace flue gas entering the vaporization cooling flue. , which is beneficial to protect the heat exchange surface of the vaporization cooling flue and prolong the service life of the vaporization cooling flue. Set up ash outlets between the heat storage walls to regularly remove the smoke and dust from the electric furnace, set up a soot blowing pipe behind the heat storage walls, and use back blowing to regularly clean the heat storage walls.

One or more air inlets are arranged on the side wall of the flue gas combustion settling chamber of the electric furnace, and a control valve is arranged outside the air inlet. During electric furnace steelmaking, the amount of air introduced into the combustion and settling chamber is controlled by the control valve to ensure the combustion of CO.

In the temperature range of electric furnace flue gas, the combustion rate of CO is mainly affected by the temperature and the mixing of CO and oxygen. The reaction of CO and oxygen to generate _CO2 is an exothermic reaction. Lower temperature is conducive to the complete reaction, but higher temperature can accelerate the rate of CO combustion reaction, so there is an optimal temperature for CO burnout. In the present invention, a water-cooled heat exchange tube is installed on the wall of the flue gas combustion and settling chamber of the electric furnace, and the temperature of the flue gas is reduced through the cooling effect of the water-cooled heat exchange tube on the flue gas, so that the temperature of the flue gas at the outlet of the combustion and settling chamber is favorable for CO burnout. within the optimum temperature range. When designing the combustion settling chamber, after determining the optimum temperature for CO burnout, determine the number of water-cooled heat exchange tubes arranged in the combustion settling chamber according to the heat balance calculation. The water-cooled heat exchange tubes arranged on the wall of the combustion and settling chamber can be used as a part of the vaporization cooling system for the waste heat recovery of the electric furnace flue gas.

The present invention also sets a smoke mixing angle on the side wall under the smoke outlet of the electric furnace, which can change the flow field of the electric furnace smoke, promote the mixing of CO and oxygen, and facilitate the burning of CO.

The present invention has the following advantages:

1) The heat storage effect on the flue gas of the electric furnace, compared with the hollow traditional combustion settling chamber, increases the thermal inertia of the combustion settling chamber, and reduces the influence of the flue gas temperature fluctuation of the electric furnace on the vaporization cooling system of the waste heat recovery device;

2) Promote the combustion of CO in the combustion settling chamber by changing the temperature in the combustion settling chamber and adding mixed smoke angle;

3) The thermal storage wall can use a particle layer, and use the particle layer filter dust removal technology to further reduce the dust content of the electric furnace flue gas entering the vaporization cooling flue on the basis of reducing the flow rate of the traditional combustion settling chamber, which is conducive to protecting the vaporization The heat exchange surface of the cooling flue prolongs the service life of the vaporization cooling flue.

In summary, the present invention can remove dust, remove dust, store heat and promote CO burnout for electric furnace flue gas, and is beneficial to recover sensible heat from electric furnace flue gas. It is an important technology for CO emission, has high economic and social benefits, and has strong promotion value.

Description of drawings

Fig. 1 is a main sectional view of the present invention;

Figure 2 is a top view of the present invention.

Part 1 is the air inlet; Part 2 is the heat storage wall; Part 3 is the flue gas inlet; Part 4 is the smoke exhaust port; Part 5 is the smoke mixing corner; Part 6 is the ash discharge port; is a control valve; item 9 is a water-cooled heat exchange tube.

Detailed ways

The present invention will be further described below in conjunction with the specific embodiment of accompanying drawing 1 and 2.

The flue gas combustion settling chamber of an electric furnace includes a flue gas inlet 3, an air inlet 1 and a smoke exhaust port 4, and a heat storage wall 2 is set in the combustion chamber; the heat storage wall 2 is made of one or more layers of heat storage bricks, and the heat storage brick There is a flue gas channel in between. A soot blowing pipe 7 is arranged behind the thermal storage wall 2 . Ash outlets 6 are arranged between the heat storage walls 2 . A control valve 6 is arranged on the air inlet 1 . A smoke mixing corner 5 is set on the side wall below the smoke exhaust port 4 of the electric furnace. Water-cooled heat exchange tubes 9 are arranged on the indoor wall.

When the electric furnace is working, the electric furnace flue gas is introduced into the combustion and settling chamber through the flue gas inlet 3. When the temperature of the electric furnace flue gas is high, the electric furnace flue gas flows through the heat storage wall 2 to heat the heat storage wall 2, and the temperature of the electric furnace flue gas decreases; with the fluctuation of the electric furnace flue gas temperature, when the electric furnace flue gas temperature is low, the electric furnace flue gas When it flows through the heat storage wall 2, it is heated by the heat storage wall 2, and the temperature rises. Due to the heat storage effect of the heat storage wall 2, the temperature of the electric furnace flue gas entering the vaporization cooling system can be regulated. The heat storage wall 2 is made of heat storage bricks, and flue gas channels are left between the heat storage bricks. The soot discharge outlet 6 is set between the heat storage walls 2 to regularly remove the smoke and dust of the electric furnace, and the soot blowing pipe 7 arranged behind the heat storage walls 2 cleans the heat storage walls 2 regularly by means of back blowing. One or more air inlets 1 are arranged on the side wall of the flue gas combustion settling chamber of the electric furnace, and a control valve 8 is arranged outside the air inlet. During electric furnace steelmaking, the amount of air introduced into the combustion and settling chamber is controlled by the control valve 8 to ensure the combustion of CO. The water-cooled heat exchange tube 9 installed on the wall of the combustion and settling chamber lowers the temperature of the flue gas through the cooling effect of the water-cooled heat exchange tube on the flue gas, so that the temperature of the flue gas at the outlet of the combustion and settling chamber is in the optimum temperature range conducive to CO burnout within. The water-cooled heat exchange tubes arranged on the wall of the combustion and settling chamber are used as a part of the waste heat recovery vaporization cooling system of the electric furnace flue gas. In addition, the smoke mixing corner 5 provided on the side wall under the smoke outlet 4 of the electric furnace can change the flow field of the smoke from the electric furnace, promote the mixing of CO and oxygen, and facilitate the burning of CO.

The difference between Embodiment 2 and Embodiment 1 is that a particle bed is arranged on the heat storage wall 2. The particles in the particle bed are made of heat storage materials. The dust content of the electric furnace flue gas in the flue is conducive to protecting the heat exchange surface of the vaporization cooling flue and prolonging the service life of the vaporization cooling flue.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention in any form. However, if it does not deviate from the content of the technical solution of the present invention, any simple changes made to the above embodiments according to the technical essence of the present invention Modifications, equivalent changes and modifications all still fall within the scope of the solutions of the present invention.

Claims (8)

1. An electric furnace flue gas combustion settling chamber, comprising a flue gas inlet (3), an air inlet (1) and a smoke exhaust port (4), characterized in that: a heat storage wall (2) is set in the combustion chamber. 2. The electric furnace flue gas combustion settling chamber according to claim 1, characterized in that: the heat storage wall (2) is made of one or more layers of heat storage bricks, and flue gas remains between the heat storage bricks aisle. 3. The electric furnace flue gas combustion settling chamber according to claim 2, characterized in that a particle bed is arranged on the heat storage wall (2). 4. The electric furnace flue gas combustion settling chamber according to claim 1, characterized in that: a soot blowing pipe (7) is arranged behind the heat storage wall (2). 5. The electric furnace flue gas combustion settling chamber according to claim 2, characterized in that: an ash outlet (6) is provided between the heat storage walls (2). 6. The electric furnace flue gas combustion settling chamber according to claim 1, characterized in that: the air inlet (1) is provided with a control valve (6). 7. The electric furnace flue gas combustion settling chamber according to claim 1, characterized in that: a smoke mixing corner (5) is provided on the side wall under the electric furnace flue gas exhaust port (4). 8. The electric furnace flue gas combustion settling chamber according to claim 1, characterized in that: water-cooled heat exchange tubes (9) are arranged on the interior wall.

Images