Energy conservation and emission reduction system utilizing sleeve kiln waste gas and control method of energy conservation and emission reduction system

Abstract

The invention discloses an energy-saving and emission-reducing system utilizing sleeve kiln waste gas and a control method thereof. The energy-saving and emission-reducing system comprises a sleeve kiln, a waste gas releasing device, a converter waste gas dedusting water device and a gas-liquid reaction device. The sleeve kiln is communicated with the waste gas release device; the converter waste gas dedusting water device comprises a water return aqueduct and an inclined plate sedimentation tank, a gas-liquid mixing reaction area is arranged in the water return aqueduct, and a gas-liquid reaction device is arranged in the gas-liquid mixing reaction area; the waste gas release device is communicated with the gas-liquid reaction device. According to the system, a large amount of carbon dioxide gas contained in the sleeve kiln waste gas is used for replacing a sodium carbonate medicament required to be added for converter waste gas dedusting water, and the waste gas and wastewater are comprehensively treated, so that the treatment cost of the sleeve kiln waste gas is reduced, and the sodium carbonate medicament is replaced by the sleeve kiln waste gas; the medicament purchasing cost and the dedusting water treatment cost are saved, and waste gas resource utilization, energy conservation and emission reduction can be realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of comprehensive treatment of waste gas and waste water, and specifically relates to an energy-saving and emission-reduction system using the waste gas of a sleeve kiln and a control method thereof. Background Art

[0002] During the production process of a sleeve kiln, the combustion of converter gas will generate a large amount of waste gas, including harmful substances such as particulate matter, carbon dioxide, sulfur dioxide, nitrogen oxides, and carbon monoxide; the waste gas of the sleeve kiln has a high temperature, a large discharge volume, and a high dust content, and direct discharge will seriously affect the ecological environment;

[0003] Converter waste gas dust removal water refers to the water used in the dust removal system for purifying converter gas during the converter steelmaking process; during the steelmaking process, lime needs to be added as a slag-making material. In wet dust removal, when the gas passes through the spraying device, dust and some harmful substances are adsorbed and carried away by the water. The used dust removal water usually contains a large amount of dust and harmful substances, especially lime powder, and the dust removal water needs to be treated to improve the water quality.

[0004] In the related art, at present, the waste gas treatment solution in the production process of a sleeve kiln is to use an electrostatic precipitator to treat it to meet the standards and then discharge it into the air, which can effectively reduce the emission of harmful substances. However, the main defects of this waste gas treatment method are that the dust collector treatment occupies a large area, the investment and operation costs are high, and a large amount of carbon dioxide in the waste gas has not been effectively utilized, and the waste gas containing a large amount of carbon dioxide has not been reduced and recycled; and the treatment method of converter waste gas dust removal water is to add inorganic flocculants (polyiron) and organic flocculants (polyacrylamide series) to reduce turbidity, and use the sodium carbonate softening method to treat the hardness of converter waste gas dust removal water. However, the treatment chemical cost of this dust removal water is high, and manual dosing operation is required, resulting in a large labor intensity for workers.

[0005] Therefore, there is an urgent need for an energy-saving and emission-reduction system using the waste gas of a sleeve kiln to comprehensively treat waste gas and waste water and achieve waste gas reduction and resource utilization. Summary of the Invention

[0006] The purpose of the present invention is to provide an energy-saving and emission-reduction system using the waste gas of a sleeve kiln and a control method thereof to solve at least one aspect of the problems and defects mentioned in the above background art.

[0007] Specifically, the first aspect of the present invention discloses an energy-saving and emission-reduction system using the waste gas of a sleeve kiln, including:

[0008] A sleeve kiln, a waste gas release device, a converter waste gas dust removal water device, and a gas-liquid reaction device;

[0009] The sleeve kiln is communicated with the waste gas release device;

[0010] The converter waste gas dust removal water device includes a return water trough and an inclined plate sedimentation tank. A gas-liquid mixing reaction zone is arranged in the return water trough, and the gas-liquid reaction device is arranged in the gas-liquid mixing reaction zone;

[0011] The waste gas release device is communicated with the gas-liquid reaction device.

[0012] The energy-saving and emission-reduction system using the waste gas of the sleeve kiln according to the present invention has at least the following beneficial effects:

[0013] The energy-saving and emission-reduction system using the waste gas of the sleeve kiln transports the waste gas with a CO 2 concentration higher than 18% in the sleeve kiln into the waste gas release device. After being shunted by the waste gas release device, the waste gas is transported to the gas-liquid reaction device. After the waste gas fully reacts in the gas-liquid reaction device, the waste gas is mixed with the dust removal water in the gas-liquid mixing reaction zone; after the waste gas and the waste water are mixed and reacted, the dust, heavy metals and their compounds in the waste gas of the sleeve kiln can be effectively removed. At the same time, the waste gas of the sleeve kiln contains a large amount of carbon dioxide gas, which can replace the sodium carbonate reagent required for the converter waste gas dust removal water, so that the waste gas and the waste water are comprehensively treated, and the synergistic effect is achieved; through the inclined plate sedimentation tank of the converter waste gas dust removal water device, the dust in the waste gas does not need to be treated by a separate dust removal device; this system not only reduces the treatment cost of the waste gas of the sleeve kiln, but also makes full use of the characteristics of the converter waste gas dust removal water, replaces the sodium carbonate reagent with the waste gas of the sleeve kiln, treats the dust removal water, greatly saves the reagent procurement and the treatment cost of the dust removal water, and can realize the resource utilization of the waste gas and energy-saving and emission-reduction.

[0014] As a further scheme of the present invention: an exhaust gas collection device is arranged between the sleeve kiln and the exhaust gas release device, and a rotary blower is arranged in the exhaust gas collection device.

[0015] By arranging an exhaust gas collection device between the sleeve kiln and the exhaust gas release device and arranging a rotary blower in the exhaust gas collection device, the exhaust gas transportation pressure can be increased to 40KPa - 60KPa, which can effectively overcome the resistance of long-distance pipeline transportation, prevent the exhaust gas from slowing down or even stagnating during transportation, ensure that the exhaust gas can be continuously and stably transported from the bottom of the sleeve kiln chimney to the exhaust gas release device, maintain the stable operation of the entire exhaust gas treatment, and improve the treatment capacity and efficiency of the entire system.

[0016] As a further scheme of the present invention: the exhaust gas collection device is provided with a gas flow regulating valve.

[0017] As a further scheme of the present invention: the waste gas flow rate in the exhaust gas collection device is controlled to be 35m 3 / min - 45m 3 / min.

[0018] By setting a gas flow regulating valve in the waste gas collection device, the waste gas flow rate in the waste gas collection device is controlled to be 35 m 3 / min - 45 m 3 / min, preferably the waste gas flow rate is controlled to be 40 m 3 / min. During the process of introducing waste gas, the gas flow rate can be appropriately adjusted according to the analysis of the dust removal water sample. When the hardness of the waste gas dust removal water is between 30 mg / L - 50 mg / L and the pH value is lower than 10.80, the waste gas delivery volume of the sleeve kiln is adjusted to 80% of the normal delivery volume, preventing excessive delivery of carbon dioxide gas and avoiding overly violent reactions or excessive precipitation in the dust removal water due to excessive delivery of carbon dioxide gas. Thus, the reaction rate and degree can be precisely controlled, making the removal of hardness ions more efficient and stable, and ensuring the treatment effect of the dust removal water.

[0019] As a further aspect of the present invention: The waste gas release device includes a main gas pipeline, and a number of gas branch pipelines are uniformly arranged on the main gas pipeline. One end of the main gas pipeline is connected to the waste gas collection device, and a number of the gas branch pipelines are connected to the gas-liquid reaction device.

[0020] Since the waste gas release device includes a main gas pipeline, a number of gas branch pipelines are uniformly arranged on the main gas pipeline, one end of the main gas pipeline is connected to the waste gas collection device, and a number of gas branch pipelines are connected to the gas-liquid reaction device. Through this waste gas release device, the waste gas transported from the sleeve kiln can be evenly distributed into the gas-liquid reaction device, enabling the waste gas to be more fully and evenly treated in the gas-liquid reaction device, and then the waste gas is released into the dust removal water of the return water flume, causing the waste gas and the dust removal water to mix in the gas-liquid mixing reaction zone; not only treating the waste gas, but also being able to use the high-content carbon dioxide in the waste gas as a sodium carbonate reagent to treat the dust removal water, realizing the comprehensive treatment of waste gas and waste water, and reducing and recycling the waste gas.

[0021] As a further aspect of the present invention: The gas-liquid reaction device includes a number of aeration devices, and a number of the gas branch pipelines are respectively connected to a number of the aeration devices.

[0022] Since the gas-liquid reaction device includes a number of aeration devices, and a number of the gas branch pipelines are respectively connected to a number of the aeration devices, the waste gas can be dispersed into the dust removal water in the form of tiny bubbles through the aeration devices, increasing the contact area between the waste gas and the dust removal water, enabling the carbon dioxide in the waste gas to more fully contact and react with the waste gas dust removal water, thereby improving the reaction efficiency and being able to more effectively remove substances such as hardness ions in the waste gas dust removal water, thus improving the water quality.

[0023] As a further solution of the present invention: a folding plate is provided at the front end of the return water flume, and an air-liquid mixing reaction zone is formed by enclosing between the front end of the return water flume and the folding plate.

[0024] The return water flume usually has a length of about 300 m. By arranging a folding plate at about 30 m from the front end of the return water flume, an air-liquid mixing reaction zone is formed by enclosing between the front end of the return water flume and the folding plate, so that the waste gas and the dust removal water react in a closed folding flow in the air-liquid mixing reaction zone, the flow rate is slowed down, the residence time is increased, the mixing reaction effect of the waste gas and the dust removal water is improved, and thus substances such as hardness ions in the waste gas dust removal water can be removed more effectively, ensuring the stability and reliability of the reaction process.

[0025] As a further solution of the present invention: the water depth of the return water flume is controlled to be 0.5 m - 1 m.

[0026] Since the water depth of the return water flume is controlled to be 0.5 m - 1 m, it can provide a suitable space for the gas-liquid reaction in the air-liquid mixing reaction zone, and within this water depth range, the waste gas can stay in the dust removal water for a longer time, increasing the gas-liquid contact time, which is beneficial to the full reaction of carbon dioxide in the waste gas with the waste gas dust removal water and improving the reaction efficiency; and if the water depth is too shallow, the aeration device may be exposed above the water surface, resulting in uneven aeration or damage; while if the water depth is too deep, it may increase the working pressure of the aeration device and affect its service life. This water depth can play a certain protective role in the aeration device in the gas-liquid reaction device, ensuring the use performance and service life of the aeration device.

[0027] The second aspect of the present invention also discloses a control method for an energy-saving and emission-reduction system using the waste gas of a sleeve kiln, including the following steps:

[0028] S1. Transport the waste gas in the sleeve kiln to the waste gas release device;

[0029] S2. Divide the waste gas into streams and aerate; the waste gas is mixed with the dust removal water in the air-liquid mixing reaction zone;

[0030] S3. Adjust the transport volume of the waste gas in the sleeve kiln according to the hardness of the waste gas dust removal water;

[0031] S4. Flocculate and precipitate the dust, heavy metals and their compounds in the waste gas of the sleeve kiln through the inclined plate sedimentation tank.

[0032] As a further solution of the present invention: the transport pressure of the waste gas in the sleeve kiln is 40 KPa - 60 KPa, the CO 2 concentration is 18% - 25%, the hardness removal rate of the waste gas dust removal water is 90% - 92%, and the pH value of the waste gas dust removal water is 9 - 11.5.

[0033] Through the control method of the energy conservation and emission reduction system that utilizes the waste gas of the shaft kiln, the waste gas that originally needed to be discharged into the air in the shaft kiln is utilized to replace the sodium carbonate reagent required in the process of treating the dedusting water of the converter waste gas, and the water quality of the dedusting water is treated. This greatly reduces the environmental pollution caused by waste gas emissions, reduces the demand for chemical reagents used to treat the dedusting water, comprehensively treats waste gas and wastewater, achieves the purpose of energy conservation and emission reduction, and improves the comprehensive utilization rate of resources; moreover, it reduces the production cost of enterprises and improves economic benefits.

[0034] Taking the venturi water system that generates 1100 m³ per hour 3 and 1600 m³ 3 of venturi water as an example, this venturi water refers to the wastewater generated by the venturi scrubber; in 1100 m³ 3 of venturi water, using the waste gas of the shaft kiln to replace the sodium carbonate reagent can save 1.2 tons of sodium carbonate reagent per day. The hardness removal rate of the dedusting water reaches 90%, and the pH value is between 9 - 11.5, with a hardness less than 30 mg / L, enabling the venturi throat to not scale throughout the year; while in 1600 m³ 3 of venturi water, the hardness removal rate of the dedusting water reaches 92%, and the pH value is between 9 - 11.5, with a hardness less than 50 mg / L. Similarly, the venturi throat does not scale throughout the year; this greatly saves the procurement cost of sodium carbonate reagent, and the hardness removal rate of the dedusting water is high, effectively improving the water quality of the venturi water, enabling it to be recycled industrially; and it greatly reduces the waste gas emissions of the shaft kiln, reducing the impact on the external air quality and environment, achieving the purpose of energy conservation and emission reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] For the convenience of those skilled in the art to understand, the present invention will be further described below in conjunction with the accompanying drawings.

[0036] Figure 1 It is a schematic structural diagram of an energy conservation and emission reduction system that utilizes the waste gas of the shaft kiln.

[0037] Reference Signs:

[0038] 1. Shaft kiln; 2. Waste gas collection device; 3. Waste gas release device; 31. Main gas pipeline; 32. Branch gas pipeline; 4. Converter waste gas dedusting water device; 41. Return water trough; 42. Inclined plate sedimentation tank; 5. Gas-liquid reaction device; 51. Aeration device. DETAILED DESCRIPTION OF THE INVENTION

[0039] To make the objectives, technical solutions, and advantages of the present invention more clearly understood, the following further specifically describes the technical solutions of the present invention through embodiments in conjunction with the accompanying drawings. In the specification, the same or similar reference numerals indicate the same or similar components. The following description of the embodiments of the present invention with reference to the accompanying drawings is intended to explain the overall inventive concept of the present invention and should not be construed as a limitation of the present invention.

[0040] In addition, in the following detailed description, for the sake of explanation, numerous specific details are set forth to provide a comprehensive understanding of the embodiments of this disclosure. However, it is obvious that one or more embodiments may be practiced without these specific details. In other instances, well-known structures and devices are shown in schematic form to simplify the drawings.

[0041] As Figure 1 shown in the embodiments of the present invention, an energy-saving and emission-reduction system using the waste gas of a shaft kiln includes: a shaft kiln 1, a waste gas collection device 2, a waste gas release device 3, a converter waste gas dust removal water device 4, and a gas-liquid reaction device 5; one end of the waste gas collection device 2 is connected to the bottom of the chimney of the shaft kiln 1, and the other end is connected to the waste gas release device 3; the converter waste gas dust removal water device 4 includes a return water trough 41 and an inclined plate sedimentation tank 42. A gas-liquid mixing reaction zone is provided in the return water trough 41, and the gas-liquid reaction device 5 is arranged in the gas-liquid mixing reaction zone; the waste gas release device 3 is connected to the gas-liquid reaction device 5; a gas concentration monitoring device is arranged in the shaft kiln 1.

[0042] The key condition to maintain stable water quality is that there should be sufficient CO in the system 3 2- to react with the continuously incorporated Ca 2+ in the dust removal water in a timely manner to generate CaCO 3 precipitates, which are discharged with the slurry; since the converter gas only contains 15-18% of CO 2 , it is not sufficient to maintain the system balance, and soda ash needs to be added passively; while the CO in the waste gas of the shaft kiln 2 is as high as 25%, which can just play the role of replacing soda ash, and at the same time, the waste gas of the shaft kiln is disposed of, achieving a synergistic effect.

[0043] When sodium carbonate contacts water, a part of it dissolves in water to form HCO 3 - , CO 3 2- , which react with Ca and Mg ions to form CaCO 3 , MgCO 3 precipitates.

[0044] CaO + H 2 O = Ca(OH) 2

[0045] Ca(OH) 2 = Ca 2+ + 2OH -

[0046] CO 2 + OH - = HCO 3 -

[0047] HCO 3 - + OH - = CO 3 2- + H 2 O

[0048] Ca 2+ + CO 3 2- = CaCO 3 ↓

[0049] In the water quality treatment system, the key to maintaining stable water quality lies in the presence of a sufficient amount of CO 3 2- (carbonate ions) in the system. Because during the dust removal process, Ca 2+ (calcium ions) continuously dissolve into the dust removal water. Only when there is enough CO 3 2- in the system can it react with Ca 2+ in time to form CaCO 3 (calcium carbonate) precipitate, and these precipitates will be discharged from the system with the slurry, thus preventing the calcium ion concentration in the water from being too high and affecting the water quality. However, the CO 2 (carbon dioxide) content in the converter gas is only 15% - 18%, and the CO 3 2- generated from it is not enough to maintain the system balance. Therefore, it is necessary to additionally input Na 2 CO 3 (soda ash) to supplement CO 3 2- ;

[0050] The CO 2 content in the waste gas of the shaft kiln is as high as 25%. The CO 2 in these waste gases can be used to replace the role of soda ash. After the CO 2 enters the system, it participates in a series of chemical reactions to generate enough CO 3 2- to meet the requirement of reacting with Ca 2+ to form a precipitate;

[0051] Dissolution and precipitation reaction of sodium carbonate: Na 2 CO 3After contacting with water, it partially dissolves in water and ionizes into CO 3 2- and Na + ,CO 3 2- will react with Ca 2+ 、Mg 2+ (magnesium ions) in water to form CaCO 3 and MgCO 3 (magnesium carbonate) precipitates, thereby reducing the concentrations of Ca 2+ and Mg 2+ in water and playing a role in softening the water quality;

[0052] The reaction of calcium oxide with water and subsequent reactions: CaO (calcium oxide) reacts with water to form Ca(OH) 2 (calcium hydroxide), and Ca(OH) 2 ionizes into Ca 2+ and OH - (hydroxide ions) in water. CO 2 reacts with OH - to first form HCO 3 - (bicarbonate ions), and HCO 3 - reacts with OH - again to form CO 3 2- and water. Finally, CO 3 2- combines with Ca 2+ to form CaCO 3 precipitate.

[0053] Specifically, the energy-saving and emission-reduction system using the waste gas of the shaft kiln passes the CO 2The waste gas with a concentration higher than 18% is transported to the waste gas release device 3 through the waste gas collection device 2. After being split by the waste gas release device 3, the waste gas is transported to the gas-liquid reaction device 5. After the waste gas fully reacts in the gas-liquid reaction device 5, the waste gas is mixed with the dust removal water in the gas-liquid mixing reaction zone; after the waste gas and the waste water are mixed and reacted, the dust, heavy metals and their compounds in the waste gas of the sleeve kiln 1 can be effectively removed. At the same time, the waste gas of the sleeve kiln 1 contains a large amount of carbon dioxide gas, which can replace the sodium carbonate reagent required to be added to the converter waste gas dust removal water, so that the waste gas and the waste water are comprehensively treated, achieving a synergistic effect; through the inclined plate sedimentation tank 42 of the converter waste gas dust removal water device 4, the dust treatment of the waste gas does not require a separate dust removal device; this system not only reduces the treatment cost of the waste gas of the sleeve kiln 1, but also makes full use of the characteristics of the converter waste gas dust removal water, uses the waste gas containing a large amount of carbon dioxide in the sleeve kiln 1 to replace the sodium carbonate reagent to treat the dust removal water, greatly saving the cost of reagent procurement and the treatment of dust removal water, and can realize the resource utilization of waste gas and energy conservation and emission reduction.

[0054] Further, a waste gas collection device 2 is provided between the sleeve kiln 1 and the waste gas release device 3, and a rotary blower (not shown in the figure) is provided in the waste gas collection device 2.

[0055] Specifically, by providing a waste gas collection device 2 between the sleeve kiln 1 and the waste gas release device 3 and a rotary blower in the waste gas collection device 2, the waste gas transportation pressure can be increased to 40 KPa - 60 KPa, and the preferred waste gas transportation pressure is 50 KPa, which can effectively overcome the resistance of long-distance pipeline transportation, prevent the waste gas from slowing down or even stagnating during transportation, ensure that the waste gas can be continuously and stably transported from the bottom of the chimney of the sleeve kiln 1 to the waste gas release device 4, maintain the stable operation of the entire waste gas treatment, and improve the treatment capacity and efficiency of the entire system.

[0056] Further, the waste gas collection device 2 is provided with a gas flow regulating valve; the waste gas flow rate in the waste gas collection device 2 is controlled to be 35m 3 / min - 45m 3 / min.

[0057] Specifically, by providing a gas flow regulating valve (not shown in the figure) in the waste gas collection device 2, the waste gas flow rate in the waste gas collection device 2 is controlled to be 35m 3 / min - 45m 3 / min, and the preferred waste gas flow rate is controlled to be 40m 3 / min, the gas flow rate can be appropriately adjusted according to the analysis of the dust removal water sample during the introduction of the waste gas. When the hardness of the waste gas dust removal water is between 30 mg / L and 50 mg / L and the pH value is lower than 10.80, the waste gas delivery volume of the sleeve kiln 1 is adjusted to 80% of the normal delivery volume to prevent excessive delivery of carbon dioxide gas and avoid overly violent reactions or excessive precipitation in the dust removal water due to excessive delivery of carbon dioxide gas, thereby accurately controlling the reaction rate and degree, making the removal of hardness ions more efficient and stable, and ensuring the treatment effect of the dust removal water.

[0058] As Figure 1 shown, the waste gas release device 3 includes a main gas pipeline 31, and a number of gas branch pipelines 32 are evenly arranged on the main gas pipeline 31. One end of the main gas pipeline 31 is connected to the waste gas collection device 2, and a number of gas branch pipelines 32 are connected to the gas-liquid reaction device 5.

[0059] Specifically, since the waste gas release device 3 includes a main gas pipeline 31, and a number of gas branch pipelines 32 are evenly arranged on the main gas pipeline 31. One end of the main gas pipeline 31 is connected to the waste gas collection device 2, and a number of gas branch pipelines 32 are connected to the gas-liquid reaction device 5. Through this waste gas release device 3, the waste gas transported from the sleeve kiln 1 can be evenly distributed into the gas-liquid reaction device 5, enabling the waste gas to be more fully and evenly treated in the gas-liquid reaction device 5, and then the waste gas is released into the dust removal water of the return water flume 41, causing the waste gas and the dust removal water to mix in the gas-liquid mixing reaction zone; not only treating the waste gas, but also being able to use the high-content carbon dioxide in the waste gas as a sodium carbonate reagent to treat the dust removal water, realizing the comprehensive treatment of waste gas and wastewater, and reducing and recycling the waste gas.

[0060] The gas-liquid reaction device 5 includes a number of aeration devices 51, and a number of gas branch pipelines 32 are respectively connected to a number of aeration devices 51.

[0061] Specifically, since the gas-liquid reaction device 5 includes a number of aeration devices 51, and a number of the gas branch pipelines 32 are respectively connected to a number of aeration devices 51. Through the aeration devices 51, the waste gas can be dispersed into the dust removal water in the form of tiny bubbles, increasing the contact area between the waste gas and the dust removal water, enabling the carbon dioxide in the waste gas to more fully contact and react with the waste gas dust removal water, thereby improving the reaction efficiency and being able to more effectively remove substances such as hardness ions in the waste gas dust removal water, thus improving the water quality.

[0062] Further, a baffle is provided at the front end of the return water flume 41, and a gas-liquid mixing reaction zone is formed by enclosing between the front end of the return water flume 41 and the baffle.

[0063] Specifically, the return water flume 41 usually has a length of about 300 m. By setting a folding plate about 30 m at the front end of the return water flume 41, a gas-liquid mixing reaction zone is formed by enclosing between the front end of the return water flume 41 and the folding plate, so that the waste gas and the dust removal water carry out a sealed folding flow reaction in the gas-liquid mixing reaction zone, slowing down the flow velocity, increasing the residence time, improving the mixing reaction effect of the waste gas and the dust removal water, and thus more effectively removing substances such as hardness ions in the waste gas dust removal water, ensuring the stability and reliability of the reaction process.

[0064] Further, the water depth of the return water flume 41 is controlled to be 0.5 m - 1 m.

[0065] Specifically, since the water depth of the return water flume 41 is controlled to be 0.5 m - 1 m, it can provide a suitable space for the gas-liquid reaction in the gas-liquid mixing reaction zone, and within this water depth range, the waste gas can stay in the dust removal water for a longer time, increasing the gas-liquid contact time, which is beneficial to the full reaction of carbon dioxide in the waste gas with the waste gas dust removal water and improving the reaction efficiency; and if the water depth is too shallow, the aeration device 51 may be exposed above the water surface, resulting in uneven aeration or damage; while if the water depth is too deep, it may increase the working pressure of the aeration device 51 and affect its service life. This water depth can play a certain protective role for the aeration device 51 in the gas-liquid reaction device 5, ensuring the use performance and service life of the aeration device 51.

[0066] The second aspect of the present invention also discloses a control method for an energy-saving and emission-reduction system using the waste gas of a sleeve kiln, including the following steps:

[0067] S1. Transport the waste gas in the sleeve kiln 1 to the waste gas release device 3;

[0068] S2. Divide the waste gas into streams and aerate it; the waste gas is mixed with the dust removal water in the gas-liquid mixing reaction zone;

[0069] S3. Adjust the transport volume of the waste gas in the sleeve kiln 1 according to the hardness of the waste gas dust removal water;

[0070] S4. Carry out flocculation precipitation on the dust, heavy metals and their compounds in the waste gas of the sleeve kiln 1 through the inclined plate sedimentation tank 42.

[0071] Further, the transport pressure of the waste gas in the sleeve kiln 1 is 40 KPa - 60 KPa, the CO 2 concentration in the sleeve kiln 1 is 18% - 25%, the hardness removal rate of the waste gas dust removal water is 90% - 92%, and the pH value of the waste gas dust removal water is 9 - 11.5.

[0072] Specifically, through the control method of the energy conservation and emission reduction system that utilizes the waste gas of the shaft kiln, the waste gas that originally needs to be discharged into the air in the shaft kiln 1 is utilized to replace the sodium carbonate reagent required in the process of treating the dedusting water for the converter waste gas, and the water quality of the dedusting water is treated. This greatly reduces the environmental pollution caused by waste gas emissions, reduces the demand for chemical reagents used to treat the dedusting water, comprehensively treats waste gas and waste water, achieves the purpose of energy conservation and emission reduction, and improves the comprehensive utilization rate of resources; moreover, it reduces the production cost of the enterprise and improves the economic benefits.

[0073] Taking the venturi water system that generates 1100 m³ 3 and 1600 m³ 3 of venturi water per hour as an example, the venturi water refers to the waste water generated by the venturi tube dust collector; in 1100 m³ 3 of venturi water, using the waste gas of the shaft kiln 1 to replace the sodium carbonate reagent can save 1.2 tons of sodium carbonate reagent per day, the hardness removal rate of the dedusting water reaches 90%, and the pH value is between 9 - 11.5, and the hardness is less than 30 mg / L, so that the venturi throat does not scale throughout the year; while in 1600 m³ 3 of venturi water, the hardness removal rate of the dedusting water reaches 92%, and the pH value is between 9 - 11.5, and the hardness is less than 50 mg / L. Similarly, the venturi throat does not scale throughout the year; this greatly saves the procurement cost of the sodium carbonate reagent, and the hardness removal rate of the dedusting water is high, effectively improving the water quality of the venturi water, enabling it to be recycled industrially; and it greatly reduces the waste gas emissions of the shaft kiln 1, reducing the impact on the external air quality and the environment, and achieving the purpose of energy conservation and emission reduction.

[0074] The specific embodiments described above further elaborate on the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only the specific embodiments of the present invention and is not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An energy-saving and emission-reduction system utilizing the exhaust gas from a sleeve kiln, characterized in that: include: A sleeve kiln (1), an exhaust gas release device (3), a converter exhaust gas dust removal water device (4), and a gas-liquid reaction device (5); The sleeve kiln (1) is connected to the exhaust gas release device (3); The converter waste gas dust removal water device (4) comprises a return water aqueduct (41) and an inclined plate sedimentation tank (42), a gas-liquid mixed reaction zone is arranged in the return water aqueduct (41), and the gas-liquid reaction device (5) is arranged in the gas-liquid mixed reaction zone; The exhaust gas release device (3) is connected to the gas-liquid reaction device (5).

2. The energy-saving and emission-reduction system utilizing the exhaust gas from the sleeve kiln according to claim 1 is characterized in that: An exhaust gas collecting device (2) is arranged between the sleeve kiln (1) and the exhaust gas releasing device (3), and a rotary fan is arranged in the exhaust gas collecting device (2).

3. The energy-saving and emission-reduction system utilizing the exhaust gas from the sleeve kiln according to claim 2 is characterized in that: The exhaust gas collecting device (2) is provided with a gas flow regulating valve.

4. The energy-saving and emission-reduction system utilizing the exhaust gas from the sleeve kiln according to claim 3 is characterized in that: The exhaust gas flow rate in the exhaust gas collection device (2) is controlled to be 35m 3 / min-45m 3 / min.

5. The energy-saving and emission-reduction system using the exhaust gas from the sleeve kiln according to any one of claims 2 to 4, characterized in that: The exhaust gas release device (3) comprises a gas main pipeline (31), on which a plurality of gas branch pipelines (32) are evenly arranged, one end of the gas main pipeline (31) is connected to the exhaust gas collection device (2), and a plurality of the gas branch pipelines (32) are connected to the gas-liquid reaction device (5).

6. The energy-saving and emission-reduction system using the exhaust gas from the sleeve kiln according to claim 5 is characterized in that: The gas-liquid reaction device (5) comprises a plurality of aeration devices (51), and the plurality of gas branch pipes (32) are respectively connected to the plurality of aeration devices (51).

7. The energy-saving and emission-reduction system using the exhaust gas from the sleeve kiln according to claim 6 is characterized in that: A folding plate is provided at the front end of the return water aqueduct (41), and the front end of the return water aqueduct (41) and the folding plate are enclosed to form the gas-liquid mixing reaction zone.

8. The energy-saving and emission-reduction system using the exhaust gas from the sleeve kiln according to claim 7 is characterized in that: The water depth of the backwater aqueduct (41) is controlled to be 0.5m-1m.

9. A control method for an energy-saving and emission-reduction system utilizing exhaust gas from a sleeve kiln according to any one of claims 1 to 8, characterized in that: The steps include: S1, conveying the exhaust gas in the sleeve kiln (1) to the exhaust gas release device (3); S2, diverting and aerating the waste gas; the waste gas is mixed with dust removal water in the gas-liquid mixing reaction zone; S3, adjusting the delivery amount of the exhaust gas in the sleeve kiln (1) according to the hardness of the exhaust gas dust removal water; S4. The dust, heavy metals and their compounds in the exhaust gas of the sleeve kiln (1) are flocculated and precipitated by the inclined plate sedimentation tank (42).

10. The control method of the energy-saving and emission-reduction system using the exhaust gas of the sleeve kiln according to claim 9, characterized in that: The exhaust gas delivery pressure in the sleeve kiln (1) is 40KPa-60KPa, the CO2 concentration in the sleeve kiln (1) is 18%-25%, the hardness removal rate of the exhaust gas dust removal water is 90%-92%, and the pH value of the exhaust gas dust removal water is 9-11.5.

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