Flue gas complementary energy recycling system of sintered brick tunnel kiln

Abstract

The utility model discloses a flue gas complementary energy recycling system for a sintered brick tunnel kiln, which is characterized in that the sintered brick tunnel kiln is divided into two parts, a drying kiln for drying wet blanks and a roasting kiln for roasting the dry blanks are formed, the direction of the dry blanks in the roasting kiln is opposite to that of airflow, and the airflow firstly passes through a cooling section to cool finished bricks; meanwhile, the flue gas is heated, and then participates in combustion in the sintering section and heating of the dry blank in the heating section, and the flue gas from the heating section enters the drying kiln to dry and preheat the wet blank, so that the roasting time and the energy consumption are greatly reduced, and meanwhile, the flue gas is cooled, and subsequent desulfurization treatment is facilitated. Smoke discharged from the drying kiln is sent back into the cooling section of the roasting kiln, and the two purposes are mainly achieved that firstly, combustible gas such as carbon monoxide, nitrogen monochloride and alkane gas still exists in the smoke and can participate in secondary combustion of the sintering section, and energy consumption can be reduced; and secondly, the flue gas contains moisture and sulfides, so that the finished bricks containing calcium oxide in the cooling section are subjected to aeration reaction, the finished bricks are prevented from being weathered and burst, and the durability of the quality of the finished bricks is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of tunnel kiln brick production, in particular to a sintered brick tunnel kiln smoke residual energy recycling system. Background Art

[0002] Tunnel kilns produce a lot of smoke during the production of sintered bricks, which has a great impact on environmental pollution, mainly air pollution. However, infrastructure is a necessity for people's lives, and it is inseparable from sintered bricks, so how to promote the emission technology of tunnel kiln smoke to meet the standards is an urgent and top priority task for each brick factory.

[0003] Patent 201920004163.5 discloses a flue gas desulfurization and dust removal system for a sintered brick tunnel kiln, including a desulfurization tower, a wet dust collector, a second air supply pipe, a third air supply pipe, a first air supply pipe and a blower. The flue gas desulfurization and dust removal system for a sintered brick tunnel kiln also includes a heat exchange and dehumidification system, which includes a water tank, a first heat exchange air duct and a separation box. The air inlet of the first heat exchange air duct is connected to the air outlet of the first air supply pipe, and the air outlet is arranged at the lower part of the inner cavity of the separation box and faces downward. The air inlet of the second air supply pipe is arranged at the upper part of the inner cavity of the separation box, and the air outlet is connected to the air inlet of the desulfurization tower. This patented technology cleverly utilizes the heat of high-temperature flue gas, and first passes the flue gas with a large amount of moisture into the heat exchange system for waste heat recovery and dehumidification, and then passes into the desulfurization tower for desulfurization, so that the desulfurization and dust removal effect of the flue gas is further improved, and the heat of the flue gas is effectively recovered.

[0004] As we all know, the emission characteristics of tunnel kiln flue gas are: first, high temperature and large amount of waste heat; second, it contains harmful gases such as dust and sulfide. The above patent thinks of flue gas heat recovery, but only considers the problem from the perspective of flue gas emission, and then comes up with a usable solution. Although the solution is desirable, it is relatively one-sided. Secondly, the flue gas passes through the desulfurization tower in a hurry, the desulfurization effect is not thorough, and the flue gas emission will not meet the standard. Utility Model Content

[0005] The purpose of the utility model is to overcome the above defects of the prior art and provide a sintered brick tunnel kiln flue gas waste energy recycling system, which aims to let the flue gas coming out of the heating section enter the drying kiln to dry and preheat the wet blanks, greatly reducing the roasting time and energy consumption, and at the same time the flue gas is also cooled, which is beneficial to the subsequent desulfurization treatment; the flue gas coming out of the drying kiln is then sent back to the cooling section of the roasting kiln to participate in the secondary combustion in the firing section, which can reduce energy consumption; furthermore, the humid flue gas produces an aeration reaction on the finished bricks in the cooling section, thereby ensuring the durability of the quality of the finished bricks.

[0006] To achieve the above objectives, the utility model is realized through the following technical solutions: A system for recycling the residual energy of flue gas in a sintered brick tunnel kiln, including a drying kiln channel and a roasting kiln channel. Wet bricks enter through the drying kiln channel to form dry bricks, and the dry bricks then enter through the roasting kiln channel to form finished products. The roasting kiln channel is divided into a heating section, a firing section, and a cooling section along the traveling direction of the dry bricks. An intake air blower is arranged on the cooling section, and a first exhaust air blower is arranged on the heating section. The flue gas enters from the cooling section, passes through the firing section, and exits from the heating section. It is characterized in that it further includes a flue gas extraction pipeline, a flue gas discharge pipeline, and a flue gas return pipeline. The air inlet end of the flue gas extraction pipeline is connected to the first exhaust air blower, the air outlet end of the flue gas extraction pipeline is connected to the drying kiln channel, the air inlet end of the flue gas discharge pipeline is connected to the drying kiln channel, the air inlet end of the flue gas return pipeline is connected to the flue gas discharge pipeline, and the air outlet end of the flue gas return pipeline is connected to the intake air blower.

[0007] The utility model divides the sintered brick tunnel kiln into two parts, forming a drying kiln for drying wet bricks and a roasting kiln for roasting dry bricks. In the roasting kiln, the traveling direction of the dry bricks is opposite to the airflow direction. The airflow first passes through the cooling section, which can cool the finished bricks and also heat itself up, and then participates in the combustion in the firing section and the heating of the dry bricks in the heating section. This greatly reduces the consumption of roasting energy. The flue gas coming out of the heating section enters the drying kiln to dry and preheat the wet bricks, greatly reducing the roasting time and energy consumption. At the same time, the flue gas is cooled down, which is beneficial for subsequent desulfurization treatment. The flue gas coming out of the drying kiln is sent back into the cooling section of the roasting kiln, mainly for two purposes. One is that there are still combustible gases in the flue gas, such as carbon monoxide, nitrogen monoxide, and alkane gases, which can participate in the secondary combustion in the firing section and reduce energy consumption. The other is that the flue gas contains moisture and sulfides, which have an aeration reaction with the finished bricks containing calcium oxide in the cooling section. Commonly known as brick bleeding, it ensures that the finished bricks do not weather or burst, thus guaranteeing the durability of the quality of the finished bricks.

[0008] Residual energy is the general term for waste heat and secondary combustible residual gas, that is, residual energy includes the generated heat and the energy that can generate heat.

[0009] Preferably, the air inlet end of the intake air blower is connected with a two-position three-way valve. The three interfaces of the two-position three-way valve are respectively connected to the air inlet end of the intake air blower, the air outlet end of the flue gas return pipeline, and natural air. The two valve working positions of the two-position three-way valve are respectively at the positions corresponding to connecting the flue gas return pipeline and natural air.

[0010] The air supply end of the roasting kiln is mainly for air input, which is mainly used for combustion and sintering during the roasting process. However, the utility model adds a two-position three-way valve to extract the flue gas after combustion from the drying kiln. The function is as described above and will not be repeated here. The two-position three-way valve here can freely adjust the air intake and flue gas intake, so as to better control the utilization of waste gas.

[0011] Preferably, the drying kiln is composed of a double-layer sandwich cavity wall, a drying cavity for wet blanks to pass through is formed in the inner cavity of the double-layer cavity wall, an insulation cavity for smoke retention is formed in the sandwich of the double-layer cavity wall, a plurality of air holes are arranged on the inner cavity wall of the double-layer cavity wall, a second exhaust fan is arranged on the outer cavity wall of the double-layer cavity wall, the second exhaust fan is connected to the air inlet end of the smoke exhaust duct, and the air outlet end of the smoke collection duct directly leads to the drying cavity.

[0012] The double-layer cavity wall design of the drying kiln is equivalent to a cover, which has a heat-insulating effect on the drying kiln and makes it more ideal for drying wet blanks.

[0013] Preferably, the power of the second exhaust fan is smaller than the power of the first exhaust fan.

[0014] Such a design cannot destroy the negative pressure in the kiln.

[0015] Preferably, a flue gas reburning channel is added between the heating section and the cooling section on the roasting kiln, the air inlet end of the flue gas reburning channel is on the heating section, the air outlet end of the flue gas reburning channel is on the cooling section, and a third exhaust fan is added at the air inlet end of the flue gas reburning channel.

[0016] The flue gas coming out of the heating section is sent back to the cooling section of the roasting kiln. The main purpose is that there are still combustible gases in the flue gas, such as carbon monoxide, nitrogen monochloride and alkane gases, which can participate in the secondary combustion in the firing section and reduce energy consumption.

[0017] Preferably, the power of the third exhaust fan is less than the power of the first exhaust fan.

[0018] Such a design cannot destroy the negative pressure in the kiln.

[0019] Beneficial effects: The utility model allows the flue gas from the heating section to enter the drying kiln to dry and preheat the wet blanks, greatly reducing the roasting time and energy consumption. At the same time, the flue gas is also cooled, which is beneficial to the subsequent desulfurization treatment; the flue gas from the drying kiln is then sent back to the cooling section of the roasting kiln to participate in the secondary combustion in the firing section, which can reduce energy consumption; furthermore, the humid flue gas produces an aeration reaction on the finished bricks in the cooling section, thereby ensuring the durability of the quality of the finished bricks. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Structural schematic diagram of the present utility model;

[0021] Figure 2 Structural schematic diagram of the drying kiln channel of the present utility model.

[0022] In the figure: 1 - drying kiln channel, 2 - roasting kiln channel, 3 - intake air blower, 4 - first air extraction blower, 5 - flue gas collection pipeline, 6 - flue gas discharge pipeline, 7 - flue gas return pipeline, 8 - two-way three-way valve, 9 - third air extraction blower, 10 - flue gas reburning channel, 11 - drying cavity, 12 - heat preservation cavity, 13 - second air extraction blower, 14 - ventilation holes. Specific embodiments

[0023] In order to make the technical means, creative features and achieved purposes of the present utility model easy to understand, the present utility model is further elaborated below in conjunction with specific embodiments.

[0024] Embodiment: As Figure 1 shown, a system for recycling the surplus energy of flue gas in a sintered brick tunnel kiln includes a drying kiln channel 1, a roasting kiln channel 2, a flue gas collection pipeline 5, a flue gas discharge pipeline 6 and a flue gas return pipeline 7.

[0025] Among them, wet bricks pass through the drying kiln channel to form dry bricks, and the dry bricks then pass through the roasting kiln channel to form finished products. The roasting kiln channel is divided into a heating section, a firing section and a cooling section along the traveling direction of the dry bricks. An intake air blower 3 is arranged on the cooling section, and a first air extraction blower 4 is arranged on the heating section. Among them, the flue gas enters from the cooling section, passes through the firing section and exits from the heating section.

[0026] The air inlet end of the flue gas collection pipeline 5 is connected to the first air extraction blower 4.

[0027] As Figure 2 shown, the drying kiln channel 1 is composed of a double-layer sandwich cavity wall. A drying cavity 11 for wet bricks to pass through is formed in the inner cavity of the double-layer cavity wall, and a heat preservation cavity 12 for flue gas to stay is formed in the sandwich of the double-layer cavity wall. A number of ventilation holes 14 are arranged on the inner cavity wall of the double-layer cavity wall, and a second air extraction blower 13 is arranged on the outer cavity wall of the double-layer cavity wall. The second air extraction blower 13 is connected to the air inlet end of the flue gas discharge pipeline 6, and the air outlet end of the flue gas collection pipeline 5 leads directly into the drying cavity 11. The power of the second air extraction blower 13 is less than the power of the first air extraction blower 4.

[0028] The air outlet end of the flue gas discharge pipeline 6 is connected to the subsequent desulfurization and dust removal environmental protection discharge system (not involved in this patent and not elaborated, and can be purchased in the market, such as a combination of a desulfurization tower and a high-altitude chimney, etc.).

[0029] The air inlet end of the flue gas return pipe 7 is connected to the flue gas discharge pipe 6, and the air outlet end of the flue gas return pipe 7 is connected to the intake air fan 3; a two-position three-way valve 8 is connected to the air inlet end of the intake air fan 3. The three interfaces of the two-position three-way valve 8 are respectively connected to the air inlet end of the intake air fan 3, the air outlet end of the flue gas return pipe 7, and natural air. The two valve working positions of the two-position three-way valve 8 are respectively at the positions corresponding to the connection of the flue gas return pipe 7 and natural air.

[0030] A flue gas reburning channel 10 is added between the heating section and the cooling section on the roasting kiln channel 2. The air inlet end of the flue gas reburning channel 10 is on the heating section, and the air outlet end of the flue gas reburning channel 10 is on the cooling section. A third air extraction fan 9 is added at the air inlet end of the flue gas reburning channel 10. The power of the third air extraction fan 9 is less than the power of the first air extraction fan 4.

[0031] Usage: The utility model divides the sintered brick tunnel kiln into two parts, forming a drying kiln for drying wet bricks and a roasting kiln for roasting dry bricks. In the roasting kiln, the direction of the dry bricks is opposite to the direction of the air flow. The air flow first passes through the cooling section, which can cool the finished bricks and at the same time the air flow itself is heated up, and then participates in the combustion in the firing section and the heating of the dry bricks in the heating section. The flue gas coming out of the heating section enters the drying kiln to dry and preheat the wet bricks, greatly reducing the roasting time and energy consumption. At the same time, the flue gas is also cooled down, which is beneficial to subsequent desulfurization treatment. The flue gas coming out of the drying kiln is sent back into the cooling section of the roasting kiln, mainly for two purposes. One is that there are still combustible gases in the flue gas, such as carbon monoxide, nitrogen monoxide, and alkane gases, etc., which can participate in the secondary combustion in the firing section and reduce energy consumption; the other is that the flue gas contains moisture and sulfides, which produce an aeration reaction on the finished bricks containing calcium oxide in the cooling section, ensuring that the finished bricks do not weather and do not burst, thus ensuring the durability of the quality of the finished bricks.

Claims

1. A system for recycling waste energy of flue gas from a sintered brick tunnel kiln, comprising a drying kiln and a roasting kiln, wherein wet blanks pass through the drying kiln to form dry blanks, and the dry blanks pass through the roasting kiln to form finished products, and the roasting kiln is divided into a heating section, a firing section and a cooling section along the direction of the dry blanks, an air intake fan is provided on the cooling section, and a first exhaust fan is provided on the heating section, wherein the flue gas enters from the cooling section, passes through the firing section, and then exits from the heating section, characterized in that: It also includes a smoke collection duct, a smoke exhaust duct and a smoke return duct, the air inlet end of the smoke collection duct is connected to the first exhaust fan, the air outlet end of the smoke collection duct is connected to the drying kiln, the air inlet end of the smoke exhaust duct is connected to the drying kiln, the air inlet end of the smoke return duct is connected to the smoke exhaust duct, and the air outlet end of the smoke return duct is connected to the air inlet fan.

2. The sintered brick tunnel kiln flue gas waste energy recycling system according to claim 1 is characterized in that: The air inlet end of the air intake fan is connected to a two-position three-way valve, wherein the three interfaces of the two-position three-way valve are respectively connected to the air inlet end of the air intake fan, the air outlet end of the smoke return duct and the natural air, and the two valve working positions of the two-position three-way valve are respectively connected to the corresponding connections to the smoke return duct and the natural air.

3. The sintered brick tunnel kiln flue gas waste energy recycling system according to claim 1, characterized in that: The drying kiln is composed of a double-layer sandwich cavity wall, a drying cavity for wet blanks to pass through is formed in the inner cavity of the double-layer cavity wall, an insulation cavity for smoke retention is formed in the sandwich of the double-layer cavity wall, a plurality of air holes are arranged on the inner cavity wall of the double-layer cavity wall, a second exhaust fan is arranged on the outer cavity wall of the double-layer cavity wall, the second exhaust fan is connected to the air inlet end of the smoke exhaust duct, and the air outlet end of the smoke collection duct directly leads to the drying cavity.

4. The sintered brick tunnel kiln flue gas waste energy recycling system according to claim 3 is characterized in that: The power of the second exhaust fan is smaller than the power of the first exhaust fan.

5. The sintered brick tunnel kiln flue gas waste energy recycling system according to claim 1, characterized in that: A flue gas reburning channel is added between the heating section and the cooling section on the roasting kiln, the air inlet end of the flue gas reburning channel is on the heating section, the air outlet end of the flue gas reburning channel is on the cooling section, and a third exhaust fan is added at the air inlet end of the flue gas reburning channel.

6. The sintered brick tunnel kiln flue gas waste energy recycling system according to claim 5, characterized in that: The power of the third exhaust fan is smaller than the power of the first exhaust fan.

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