Adjustable swirl vane device, lower burner and annular sleeve kiln

Abstract

The utility model discloses an adjustable swirl vane device, a lower burner and an annular sleeve kiln, and belongs to the field of high efficiency, energy conservation and environmental protection. The lower combustor of the annular sleeve kiln comprises a gas pipe, a primary air pipe, a volute and a combustion chamber, a gas swirl vane is arranged in an inner annular channel of the gas pipe and rotates through a vane transmission assembly, and the adjustable rotation angle ranges from 30 degrees to 55 degrees. The blade transmission assemblies are evenly distributed on the outer wall of the gas pipe in the circumferential direction. According to the adjustable swirl vane device, the rotation angle of the fuel gas swirl vane can be flexibly adjusted, the swirl strength of fuel gas is effectively enhanced, the adjustable swirl vane device is applied to an annular sleeve kiln, the swirl strength of the fuel gas can be effectively enhanced, and the concentration of CO in flue gas is reduced.

Description

Technical Field

[0001] The utility model belongs to the field of high efficiency, energy saving and environmental protection, and more specifically, relates to an adjustable swirl blade device, a lower burner and an annular sleeve kiln. Background Art

[0002] Lime is a gas-hardening inorganic gelling material widely used in metallurgy, construction, chemical industry and other fields. Among them, calcium carbide gas produced with lime as the main raw material is rated as the mother of organic industry. With the rapid growth of demand for polyvinyl chloride in the international and domestic markets, closed calcium carbide furnaces are often built together with lime kilns to improve production efficiency. Therefore, the annular sleeve lime kiln has become the preferred kiln type for calcining high-quality active quicklime using the tail gas of a closed calcium carbide furnace. It is mainly composed of a steel outer shell of the kiln body and a refractory lining and upper and lower inner sleeves arranged concentrically therewith. The vertical kiln is provided with upper and lower layers of burners, which are evenly staggered. The characteristics of countercurrent calcination and parallel calcination, and the organic combination of underoxygen combustion and overoxygen combustion are adopted to achieve effective control of lime quality.

[0003] Patent CN204694090U discloses a control device for utilizing the flue gas waste heat after the annular sleeve kiln heat exchanger. It mainly uses the negative pressure of the lower combustion chamber of the annular sleeve kiln as the adjustment basis. Through the control unit, it adjusts the balance between the production of the annular sleeve kiln and the utilization of the flue gas waste heat of the user in real time to ensure the reasonable and efficient utilization of the flue gas waste heat after the annular sleeve kiln heat exchanger. In order to reduce NO in production x The combustion process generally adopts flue gas recirculation technology, which uses the low temperature and low oxygen characteristics of flue gas to make the high temperature flue gas generated by combustion flow back and participate in the combustion for the second time. When the flue gas is sprayed into the furnace again, the combustion rate and the local temperature in the furnace are reduced due to the flue gas absorbing heat and diluting the oxygen concentration in the mixed gas, and the formation of a reducing atmosphere will reduce the generated NO x Reduction, thereby achieving the purpose of inhibiting the generation of nitrogen oxides. For example, CN111592241A discloses a sleeve kiln low NO x The combustion process comprises the steps of: feeding, limestone preheating, countercurrent calcination, parallel calcination and lime cooling, wherein the upper combustion chamber in the countercurrent calcination step uses a staged combustion low NO xThe burner divides the combustion into a central primary combustion zone, a peripheral secondary combustion zone and a burnout zone; in the parallel calcination step, the extended ejector and the ejection channel with an extended ejection port drive more circulating gas into the lower combustion chamber; in the lime cooling step, under the premise of controlling the total lime cooling air volume, a part of the lime cooling air enters the upper part of the kiln bottom silo through the self-priming cooling air duct, and the other part of the lime cooling air enters the kiln bottom silo material layer through the cooling air ring pipe. However, due to the decrease in the global oxygen concentration during the combustion process, the problem of high CO concentration in the outlet flue gas is generated. However, in the current existing technology, this problem has not been solved. With the increasingly tight energy supply and the increasingly serious environmental pollution, the efficient and low-pollution utilization of energy has become the current primary goal.

[0004] The above studies on the burner under the annular sleeve kiln have all failed to solve the problem of high CO concentration in the outlet flue gas due to the reduction of global oxygen concentration during the combustion process under the flue gas circulation nitrogen reduction technology. Summary of the invention

[0005] 1. Problems to be solved

[0006] Introducing circulating flue gas into the existing annular sleeve kiln to reduce NO x After discharge, the oxygen concentration decreases, resulting in a higher CO concentration in the outlet flue gas. The utility model provides an adjustable swirl blade device, which can flexibly adjust the rotation angle of the swirl blade to effectively reduce the CO concentration in the flue gas.

[0007] Another object of the utility model is to provide an annular sleeve kiln lower burner including the adjustable swirl blade device, wherein the angle of the gas swirl blade in the lower burner can be rotated to effectively reduce the concentration of CO in the flue gas;

[0008] Another object of the utility model is to provide an annular sleeve kiln comprising the annular sleeve kiln lower burner, in NO x The concentration of CO in the flue gas is effectively reduced without a significant increase in emissions.

[0009] 2. Technical solution

[0010] To solve the above problems, the utility model adopts the following technical solutions.

[0011] An annular sleeve kiln underburner comprises a gas pipe, a primary air duct, a volute and a combustion chamber, wherein a gas swirl blade is arranged in the gas pipe, and the gas swirl blade has an adjustable rotation angle range of 30° to 55°, preferably 40° to 45°, the gas pipe is an internal annular channel with an inner diameter, the primary air duct is sleeved outside the gas pipe, an external annular channel for primary air to pass through is formed between the primary air duct and the gas pipe, primary air swirl blades are arranged in the external annular channel, the gas swirl blades and the primary air swirl blades are on the same cutting plane, a flare is arranged behind the primary air duct, the primary air and the gas are mixed and burned at the flare, a volute is arranged behind the flare, a secondary air inlet is opened on the side of the volute, the secondary air is introduced along the inner wall of the secondary air inlet on the side of the volute, one end of the volute is connected to the flare, and the other end is connected to the combustion chamber, and the secondary air then reacts with the unreacted gas in the combustion chamber.

[0012] The gas swirl blades are rotated by a blade transmission assembly, and the blade transmission assembly includes a rotating unit and a limiting unit. The rotating unit and the limiting unit are slidably connected and evenly distributed on the outer wall of the gas pipe along the circumferential direction.

[0013] The rotating unit includes a rotating shaft fixedly connected to the gas swirl blade, and the gas swirl blade rotates along the rotating shaft to adjust the angle of the gas swirl blade; the rotating shaft includes a sleeve located in the gas pipe and a rotating shaft body sleeved and fixed in the sleeve, the lower end of the rotating shaft body is rotatably connected to the pipe wall of the gas pipe, and the upper end of the rotating shaft body extends out of the pipe wall of the gas pipe and is connected to the limiting unit.

[0014] The rotation connection can be achieved by inserting the lower end of the rotating shaft into a through hole opened in the wall of the gas pipe, or the lower end of the rotating shaft is matched with a rolling bearing, and then the rolling bearing is fixedly connected to the wall of the gas pipe.

[0015] Furthermore, in order to accurately control the rotation angle of the gas swirl blades, a scale dial is provided on the outer wall of the gas pipe, and the scale dial is fixed to the outer wall of the gas pipe. The scale dial is sleeved on the outer periphery of the rotating shaft, and the rotating shaft rotates in a through hole opened in the middle of the scale dial. A pointer is provided on the side wall of the gas pipe where the rotating shaft extends out of the gas pipe. The pointer is fixedly connected to the rotating shaft. By rotating the pointer, the rotating shaft is driven to rotate, and then the gas swirl blades are rotated, so that the rotation angle of the gas swirl blades can be observed.

[0016] The limit unit includes a connecting ring, a guide pin and a swing rod. A positioning hole is provided at one end of the guide pin. The upper end of the rotating shaft passes through the positioning hole and is fixedly connected to a nut to limit the upper end of the rotating shaft in the positioning hole. A guide groove is provided at the other end of the guide pin. The swing rod is slidably connected in the guide groove. The bottom of the swing rod is fixedly connected to the connecting ring. The connecting ring is sleeved on the outside of the gas pipe. When adjusting the angle of the gas swirl blade, the blade transmission assembly drives the gas swirl blade to rotate under the rotation of the rotating shaft by rotating the guide pin. The angle adjustment can be monitored in real time by observing the angle on the scale dial.

[0017] In order to control the rotation angle of the gas swirl blade within the range of 30° to 55°, preferably within the range of 40° to 45°, and to prevent the gas swirl blade from rotating too much or getting stuck, the limit unit also includes a slide rod, and the connecting ring is provided with a through hole for the slide rod to pass through, one end of the slide rod is rotatably connected to the opening of the connecting ring, and the other end is fixed to the outer wall of the gas pipe. In the actual structure, two small slide rings can also be provided on the slide rod to fix the position of the connecting ring.

[0018] The annular sleeve kiln has a complex structure and complicated internal airflow. x At the same time as the emission, the global oxygen concentration decreases during the combustion process, resulting in a problem of high CO concentration in the outlet flue gas. The adjustable swirl blade device is used to flexibly adjust the angle of the gas swirl blade while controlling the adjustable rotation angle of the blade to be within the range of 30o to 55o, preferably 40o to 45o, which greatly reduces the CO concentration in the outlet flue gas and improves the fuel burnout rate.

[0019] The utility model utilizes the guiding effect of the swirl blades on the flow direction of the combustion-supporting gas to make the combustion-supporting gas move closer to the combustion gas, thereby improving the mixing effect between the gases. When the combustion gas flow passes through the swirl blades, the axial motion will be changed into rotational motion, and the air flow will be thrown around by the inertial centrifugal force, making the air in the center of the combustion chamber thin, forming a low-pressure area, and the air around the combustion chamber and a part of the high-temperature combustion gas at the rear will flow back to the low-pressure area of ​​the combustion chamber, forming a reflux, making the axial velocity of the air flow relatively small, forming a stable ignition source, and improving the combustion efficiency.

[0020] Among them, the swirl blade angle can be used to control the size of the circulating air volume and also to adjust the size of the tangential component of the inlet wind speed. The above two together determine the size of the swirl intensity of the burner nozzle flow field. The swirl blade angle usually refers to the angle between the inner swirl blade and the axis in the cyclone. The size of this angle is usually between 10° and 60°, and different application scenarios require different blade angles. Under normal circumstances, the smaller the swirl blade angle, the greater the centrifugal force and the more obvious the material particle size separation effect. However, in practical applications, too small a blade angle will cause excessive fluid pressure inside the equipment, which will lead to equipment failure; when processing high viscosity or carrying large particle materials, it is necessary to select a swirl blade with a larger angle to better separate the materials and improve the equipment processing capacity. However, too large a swirl blade angle will also cause excessive fluid kinetic energy loss inside the equipment, thereby affecting the processing efficiency of the equipment. Therefore, the utility model combines the structural dimensions of the annular sleeve kiln underburner and the combustion characteristics of the calcium carbide furnace gas fuel to determine the optimal swirl blade angle range.

[0021] In addition, after researching and comparing the effects of various factors such as flue gas recirculation ratio, primary air oxygen concentration, secondary air oxygen concentration, and burner structure on the fuel burnout rate, the utility model took into account the structural complexity of the annular sleeve kiln, and in order to achieve the greatest improvement effect with the smallest change, it finally chose to improve the angle of the gas swirl blades with the best effect of reducing pollutant emissions. The reason for improving the angle of the gas swirl blades is related to the amount of air flowing in the gas pipe and the primary air duct. In actual use, the amount of gas introduced is greater than the circulating gas introduced into the primary air duct. For example, when 713Nm is introduced into the gas pipe, 3 / h of gas, 275Nm 3 / h of circulating gas, when the blade angle increases, the airflow in the gas pipe will be more disturbed by the blades, so the effect of changing the gas swirl angle on the overall combustion characteristics will be more obvious. In addition, the initial manufacturer's gas swirl angle is 30°, but when the gas swirl angle is <30°, the gas mixing and entrainment ability is poor, and the fuel burnout rate is low; when the gas swirl angle is >55°, the swirl intensity is too large, causing the ignition to be too early, and the flame center is close to the burner outlet. At the same time, the pressure loss on the tube wall increases sharply, causing the refractory material on the inner wall of the kiln body to burn. When the swirl blade angle increases from 30° to 55°, at this time, the CO concentration in the outlet flue gas is significantly reduced, but the pressure loss on the tube wall increases. In summary, the adjustable gas swirl blade angle in the utility model is in the range of 30° to 55°, preferably 40° to 45°.

[0022] The swirl intensity has an important influence on the aerodynamic conditions in the furnace. If the swirl intensity is large, the airflow rotates strongly, which increases the airflow expansion angle and the reflow area, and increases the amount of hot flue gas that flows back to the flame root; the turbulent diffusion of the airflow is enhanced, and the early mixing process is accelerated; the axial velocity decays faster, and the airflow (flame) range is shortened. At the same time, the resistance of the burner also increases. Obviously, for swirl burners, ensuring the necessary swirl intensity is very important for ignition and combustion.

[0023] Increasing the angle of the gas swirl blades and improving the fuel burnout rate should also avoid excessive pressure loss on the inner wall of the kiln. Therefore, when designing a swirl burner, it is necessary to select a suitable swirl intensity. In summary, the utility model proposes an annular sleeve kiln with an adjustable swirl blade lower burner, and the adjustable gas swirl blade angle ranges from 30o to 55o, preferably from 40o to 45o.

[0024] The swirl intensity is evaluated by the swirl number, and the swirl number S of the swirl blade is n for:

[0025]

[0026] Among them, β is the installation angle of the blade, r / R is the hub ratio of the axial swirler, among which r is the fitting surface of the lower end of the gas swirl blade and the radius of the central ignition rod, and R is the fitting surface of the upper end of the gas swirl blade and the inner diameter of the gas pipe.

[0027] Preferably, the installation angle of the swirl blade is 40° to 45°, and the swirl intensity of the swirl blade is 0.6 to 0.72.

[0028] The primary air is the chimney circulating gas and the secondary air is a mixture of driving air and induced circulating air.

[0029] In order to reduce NO x The combustion process generally adopts flue gas recirculation technology. It mainly utilizes flue gas recirculation air combined with secondary graded swirl combustion to make the high-temperature flue gas generated by the lower burner reflux and participate in the combustion for the second time. Because the flue gas absorbs heat and dilutes the oxygen concentration in the mixed gas, the combustion rate and the temperature in the furnace are reduced, thereby achieving the purpose of inhibiting the generation of nitrogen oxides. Among them, the circulating gas introduced into the annular sleeve kiln refers to the fuel and combustion-supporting air entering from the lower burner. After fully reacting with the limestone raw material in the parallel combustion zone at the bottom of the lower combustion chamber, it enters the upper section of the lower inner sleeve of the annular sleeve together with the cooling air entering from the cooling zone at the bottom of the kiln, and then flows into the ejector through the circulating gas channel pipe in the upper arch bridge, and is mixed with the hot air in the ejector pipe and ejected into the lower combustion chamber again.

[0030] The utility model discloses an adjustable swirl blade device for an annular sleeve kiln and an annular sleeve kiln underburner. After studying the influence of swirl intensity on combustion temperature distribution, pressure distribution and combustion products such as CO, CO2, and NO, by increasing the angle of the gas swirl blade, the mixing and entrainment effect of the recirculation zone on the gas can be enhanced, thereby increasing the combustion rate of the fuel. The problem of a high CO concentration in the outlet flue gas due to the reduction of the global oxygen concentration during the combustion process under the flue gas circulation nitrogen reduction technology is solved. The swirl burner can maintain NO in the outlet flue gas. x The content meets the limit value of 200mg / Nm required by the "Emission Standards of Air Pollutants from Lime and Calcium Carbide Industry" 3 @10% O2, the CO content of the incomplete combustion product at the inner sleeve position is reduced by about 43%. It not only complies with the energy-saving and emission-reduction strategy advocated by the country, but also meets the process requirements of improving heat utilization and reducing heat consumption of the sleeve kiln.

[0031] The lower burner is applied to an annular sleeve kiln, which comprises a steel outer shell of a kiln body, a refractory lining and upper and lower inner sleeves arranged concentrically therewith, and a plurality of upper burners and a plurality of lower burners are arranged in a vertical kiln, and the upper burners and the lower burners are arranged evenly staggered. The lower burner of the annular sleeve kiln is located between the lower outer sleeve and the lower inner sleeve of the annular sleeve kiln, and is evenly distributed around the circumference of the annular sleeve.

[0032] 3. Beneficial effects

[0033] Compared with the prior art, the beneficial effects of the utility model are:

[0034] (1) The utility model provides an adjustable swirl blade device that can flexibly adjust the rotation angle of the gas swirl blade, effectively enhancing the swirl intensity of the gas, increasing the oxygen concentration, and reducing the CO concentration in the outlet flue gas;

[0035] (2) The utility model discloses an annular sleeve kiln underburner, in which the angle of the gas swirl blades can be rotated. By installing an adjustable swirl blade device in the annular channel inside the gas pipe of the annular sleeve kiln underburner, the angle of the gas swirl blades can be adjusted to make the blades rotate synchronously, and the swirl blades can be flexibly adjusted to effectively enhance the swirl intensity of the gas and reduce the concentration of CO in the flue gas;

[0036] (3) The utility model is an annular sleeve kiln burner, which effectively enhances the swirl intensity of the gas by controlling the angle of the gas swirl blade to rotate within the range of 30° to 55°, preferably 40° to 45°, so as to maintain stable combustion, strengthen the internal recirculation zone, and promote the mixing of the combustion-supporting gas and the gas, while ensuring the thermal NO x The amount of production did not increase significantly, but the CO concentration in the outlet flue gas decreased significantly;

[0037] (4) The adjustable swirl blade device of the utility model is provided with a limit unit to control the rotation angle of the gas swirl blade and prevent the gas swirl blade from rotating too much or getting stuck;

[0038] (5) The annular sleeve kiln of the utility model, including the annular sleeve kiln with a lower burner of the annular sleeve kiln, is x The concentration of CO in flue gas is effectively reduced without a significant increase in emissions;

[0039] (6) The utility model not only complies with the energy-saving and emission-reduction strategy advocated by the state, but also meets the technological requirements of improving heat utilization and reducing heat consumption of sleeve kilns. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The technical solution of the utility model will be further described in detail below in conjunction with the accompanying drawings and embodiments, but it should be understood that these drawings are designed only for the purpose of explanation and are not intended to limit the scope of the utility model. In addition, unless otherwise specified, these drawings are only intended to conceptually illustrate the structural configurations described herein and are not necessarily drawn to scale.

[0041] Figure 1 This is a schematic diagram of the structure of the lower burner of the annular sleeve kiln;

[0042] Figure 2 This is a partial enlarged view of the lower burner of the annular sleeve kiln;

[0043] Figure 3 This is a structural diagram of the gas swirl blade of the utility model;

[0044] Figure 4 This is a schematic diagram of the structure of the adjustable swirl blade device of the utility model;

[0045] Figure 5 This is a cross-sectional view of the structure of the adjustable swirl blade device of the utility model;

[0046] Figure 6 This is an enlarged view of the structure of the adjustable swirl blade device of the utility model;

[0047] Figure 7 This is an enlarged side view of the structure of the adjustable swirl blade device of the utility model;

[0048] Figure 8 This is an enlarged view of the structure of the gas swirl blade of the utility model;

[0049] Fig. 9 The structure diagram of the gas swirl blade of Examples 1-6, wherein (a) 30°; (a) 35°; (a) 40°; (a) 45°; (a) 50°; (a) 55°;

[0050] Fig.10 The cross-sectional view of the gas swirl blade structure of Embodiment 1-6, wherein (a) 30°; (a) 35°; (a) 40°; (a) 45°; (a) 50°; (a) 55°;

[0051] Fig.11 The temperature distribution on the axial center line of the lower burner of the annular sleeve kiln;

[0052] Fig.12 The average CO concentration distribution along the burner of the annular sleeve kiln;

[0053] Fig.13 The average NO concentration distribution along the burner of the annular sleeve kiln;

[0054] Fig.14 The CO concentration variation curve at the inner sleeve position under different gas swirl blade angles;

[0055] Fig.15 The NO concentration variation curve at the inner sleeve position under different gas swirl blade angles;

[0056] In the figure: 1, gas pipe; 11, gas swirl blade; 12, internal annular channel;

[0057] 2. Primary air duct; 21. Primary air swirl blades; 22. External annular channel; 23. Primary air inlet;

[0058] 3. Expanding;

[0059] 4. Volute; 41. Secondary air inlet;

[0060] 5. Combustion chamber;

[0061] 6. Blade transmission assembly; 61. Rotation unit; 611. Rotation shaft; 6111. Sleeve; 6112. Rotation shaft body; 612. Nut; 614. Scale dial; 62. Limit unit; 621. Connecting ring; 622. Guide pin; 6221. Guide groove; 623. Rocker; 624. Slide rod. DETAILED DESCRIPTION

[0062] The following detailed description and example embodiments of the present invention may be better understood in conjunction with the accompanying drawings, in which elements and features of the present invention are identified by reference numerals.

[0063] An annular sleeve kiln underburner, such as Figure 1-3As shown, it includes a gas pipe 1, a primary air pipe 2, a volute 4 and a combustion chamber 5. The gas pipe 1 includes an internal annular channel 12 with an inner diameter, and a gas swirl blade 11 is arranged in the internal annular channel 12. The rotation angle of the adjustable gas swirl blade 11 is 30° to 55°, preferably 40° to 45°. The primary air pipe 2 is sleeved outside the gas pipe 1, and an external annular channel 22 for primary air to pass through is formed between the primary air pipe 2 and the gas pipe 1. The external annular channel 22 is provided with a primary air swirl blade 21, and the angle between the primary air swirl blade 21 and the axis is 30°. The gas swirl blades 11 and the primary air swirl blades 21 are on the same cutting plane, the primary air inlet 23 is provided on the side of the primary air duct 2, and a flare 3 is provided behind the primary air duct 2, and the primary air and the gas are mixed and burned at the flare 3, and a volute 4 is provided behind the flare 3, and a secondary air inlet 41 is provided on the side of the volute 4, which is used to introduce secondary air into the volute 4 and then react with the unreacted gas, and one end of the volute 4 is connected to the flare 3, and the other end is connected to the combustion chamber 5. The gas swirl blades 11 have the important functions of strengthening internal reflux and promoting the mixing of gas and combustion-supporting gas.

[0064] Among them, in this embodiment, the gas swirl blade 11 is 58 mm long, 43 mm wide and 3 mm thick; the primary air swirl blade 21 is 68 mm long, 26 mm wide and 3 mm thick.

[0065] Gas along The primary air enters along the primary air inlet 23. The primary air and the gas are first mixed and burned at the expansion 3, as shown in the figure. The secondary air enters along the inner wall of the secondary air inlet 41 of the volute 4 with C=700mm, and then reacts with the unreacted gas inside the volute 4, as shown in the figure. Eight gas swirl blades 11 are evenly arranged in the gas channel, and eight primary air swirl blades 21 are evenly arranged in the primary air duct 2.

[0066] The gas swirl blades 11 are rotated by the blade transmission assembly 6, and the blade transmission assembly 6 includes a rotation unit 61 and a limit unit 62. The rotation unit 61 and the limit unit 62 are slidably connected and evenly distributed on the outer wall of the gas pipe 1 along the circumferential direction. Figure 4-8 shown.

[0067] The rotating unit 61 includes a rotating shaft 611 fixedly connected to the gas swirl blade 11, and the gas swirl blade 11 rotates along the rotating shaft 611 to adjust the angle of the gas swirl blade 11; the rotating shaft 611 includes a sleeve 6111 located in the gas pipe 1 and a rotating shaft body 6112 fixedly sleeved in the sleeve 6111, the lower end of the rotating shaft body 6112 is rotatably connected to the pipe wall of the gas pipe 1, and the upper end of the rotating shaft body 6112 extends out of the pipe wall of the gas pipe 1 and is connected to the limiting unit 62. The angle adjustment of the gas swirl blade 11 can be achieved by rotating the rotating shaft 611.

[0068] The rotation connection can be achieved by inserting the lower end of the rotating shaft 6112 into a through hole opened in the wall of the gas pipe 1, or the lower end of the rotating shaft 6112 is equipped with a rolling bearing, and then the rolling bearing is fixedly connected to the wall of the gas pipe 1.

[0069] A graduated dial 613 is provided on the outer wall of the gas pipe, and the graduated dial 613 is fixed on the outer wall of the gas pipe 1. The graduated dial 613 is sleeved on the outer periphery of the rotating shaft 611. The rotating shaft 611 rotates in a through hole opened in the middle of the graduated dial 613. A pointer is provided on the side wall of the rotating shaft 611 extending out of the gas pipe 1. The pointer is fixedly connected to the rotating shaft 611. By rotating the pointer, the rotating shaft 611 is driven to rotate, and then the gas swirl blade 11 is rotated, so that the rotation angle of the gas swirl blade 11 can be observed.

[0070] The limiting unit 62 includes a connecting ring 621, a guide pin 622 and a rocker arm 623. A positioning hole is provided at one end of the guide pin 622. The upper end of the rotating shaft passes through the positioning hole and is fixedly connected to the nut 612. A guide groove 6221 is provided at the other end of the guide pin 622. The rocker arm 623 is slidably connected in the guide groove 6221. The bottom of the rocker arm 623 is fixedly connected to the connecting ring 621. The connecting ring 621 is sleeved on the outside of the gas pipe 1.

[0071] The adjustable swirl blade device of the annular sleeve kiln of the utility model has an adjustable angle range of 30°-55°. In order to control the rotation angle of the gas swirl blade 11 within the preferred range of 40°~45° and prevent the gas swirl blade 11 from rotating too much or getting stuck, the limiting unit 62 also includes a slide rod 624, and a through hole for the slide rod 624 to pass through is provided on the connecting ring 621. One end of the slide rod 624 is rotatably connected to the opening of the connecting ring 621, and the other end is fixed to the outer wall of the gas pipe 1.

[0072] The swirl number S of the gas swirl blade 11 n for:

[0073]

[0074] Wherein, β is the installation angle of the gas swirl blade 11, r / R is the hub ratio of the axial swirler, wherein r=20 mm, R=63 mm.

[0075] The primary and secondary air are circulating gases. The primary air is 275Nm 3 / h chimney circulating gas, secondary air is 1133Nm 3 / h driving air and 2850Nm 3 / h of mixed gas composed of induced circulating wind.

[0076] The working conditions in the embodiment are: 713Nm is introduced into the gas pipe 1. 3 / h of gas, 3983Nm 3 / h of driving air and induced circulating air. The components and parameters of fuel gas, primary air and secondary air are shown in Table 2-4.

[0077] Table 1 Gas swirl blade angles and process parameters of Examples 1-6

[0078] Example 1 2 3 4 5 6 Gas swirl blade angle / ° 30 35 40 45 50 55 Swirl number 0.41 0.50 0.60 0.72 0.86 1.02 Pressure loss / pa 127 140 158 183 208 252 Tangential rotation speed of airflow / m / s 32.68 36.05 38.28 43.07 48.25 58.47 <![CDATA[CO content / mg / m 3 > 8929 6866 5524 4697 3688 2467 Maximum flame temperature in furnace / K 2010 2013 2016 2018 2023 2026 <![CDATA[NO x Content / mg / m 3 ]]> 77.3 92.2 93.4 96.5 97.3 97.1

[0079] Table 2 Gas components and parameters of Examples 1-6

[0080]

[0081]

[0082] Table 3 Primary air components and parameters of Examples 1-6

[0083] <![CDATA[O2 / %]]> <![CDATA[CO2 / %]]> <![CDATA[H2O / %]]> <![CDATA[N2 / %]]> Temperature / K <![CDATA[Flow rate / Nm 3 / h]]> 7.80 33.68 1.8 56.72 498 275

[0084] Table 4 Secondary air components and parameters of Examples 1-6

[0085] <![CDATA[O2 / %]]> <![CDATA[CO2 / %]]> <![CDATA[H2O / %]]> <![CDATA[N2 / %]]> Temperature / K <![CDATA[Flow rate / Nm 3 / h]]> 14.53 19.88 3.51 62.08 1064 3983

[0086] As can be seen from Examples 1-6, by using the annular sleeve kiln underburner of the utility model, the swing rod 623 is driven to move in the guide groove 6221 of the guide pin 622, thereby driving the gas swirl blade 11 to rotate synchronously. By using the adjustable swirl blade device, the angle of the gas swirl blade 11 can be increased from 30° to 55°, preferably 40° to 45°, and the swirl number can be increased from 0.41 to 0.72. The schematic diagram of the gas swirl blade 11 is shown in FIG. Figure 9-10 At this time, the mixing and entrainment of the airflow becomes stronger, the mixing between gases becomes more intense, and the combustion rate of the fuel is improved.

[0087] like Figure 11-15As shown, by using the annular sleeve under-kiln burner of the utility model, the angle of the gas swirl blade 11 can be increased from 30o to 55o, preferably 40°~45°, the swirl intensity is increased, the airflow rotates strongly, and the airflow expansion angle and the recirculation area are increased. Turbulent diffusion is enhanced, the early mixing process is accelerated, and the tangential rotation speed of the circumferential airflow in the tube is increased from 32.68m / s to 43.07m / s. Because the swirl blades guide the flow direction of the gas, the combustion-supporting gas will get closer to the gas and react, which significantly increases the oxygen consumption per unit time and improves the burnout rate of the fuel. At this time, the CO content at the inner sleeve position is increased from 8929mg / m 3 Reduced to 4697 mg / m 3 , the CO content reduction rate is about 43%.

[0088] The angle of the gas swirl blade 11 is increased from 30o to 55o, and the local high temperature area inside the furnace moves toward the fuel nozzle. The high temperature area of ​​the flame in the furnace rises from 2010K to 2018K, which accelerates the rate at which N2 in the air is oxidized at high temperature to generate nitrogen oxides. The thermal NO x The amount of NO generated in the outlet flue gas is slightly increased. x The content is 77.3mg / m 3 Increased to 96.5 mg / m 3 While ensuring that the CO concentration in the outlet flue gas is reduced, it always meets the limit value of 200mg / Nm required by the "Emission Standards of Air Pollutants from Lime and Calcium Carbide Industry". 3 @10% O2.

Claims

1. An adjustable swirl blade device, comprising a gas swirl blade (11), wherein the gas swirl blade (11) is arranged in a gas pipe (1), characterized in that: The gas swirl blade (11) is rotated by a blade transmission assembly (6), wherein the blade transmission assembly (6) comprises a rotation unit (61) and a limit unit (62). The rotating unit (61) comprises a rotating shaft (611) fixedly connected to the gas swirl blade (11), and the gas swirl blade (11) rotates along the rotating shaft (611); The limiting unit (62) comprises a connecting ring (621), a guide pin (622) and a swing rod (623); one end of the guide pin (622) is fixedly connected to the upper end of the rotating shaft (611); the other end of the guide pin (622) is provided with a guide groove (6221); the swing rod (623) is slidably connected in the guide groove (6221); the bottom of the swing rod (623) is fixedly connected to the connecting ring (621); and the connecting ring (621) is sleeved on the outside of the gas pipe (1).

2. The adjustable swirl blade device according to claim 1, characterized in that: The rotating shaft (611) comprises a sleeve (6111) located in the gas pipe (1) and a rotating shaft body (6112) fixedly sleeved in the sleeve (6111); the lower end of the rotating shaft body (6112) is rotatably connected to the wall of the gas pipe (1); and the upper end of the rotating shaft body (6112) extends out of the wall of the gas pipe (1) and is connected to the limiting unit (62).

3. The adjustable swirl blade device according to claim 2, characterized in that: A scale dial (613) is fixedly arranged on the outer wall of the gas pipe (1), and the scale dial (613) is sleeved on the outer wall of the rotating shaft (611). A pointer is arranged on the outer wall of the rotating shaft (611), and the pointer is fixedly connected to the outer wall of the rotating shaft (611).

4. The adjustable swirl blade device according to claim 1, characterized in that: The limiting unit (62) also includes a sliding rod (624), and the connecting ring (621) is provided with a through hole for the sliding rod (624) to pass through. One end of the sliding rod (624) is connected to the opening of the connecting ring (621), and the other end is fixed to the outer wall of the gas pipe (1).

5. An adjustable swirl blade lower burner for an annular sleeve kiln, comprising the adjustable swirl blade device according to any one of claims 1 to 4, characterized in that: The invention comprises a gas pipe (1) and a primary air pipe (2), wherein the gas pipe (1) comprises an internal annular channel (12) having an inner diameter, wherein a gas swirl blade (11) is arranged in the internal annular channel (12), wherein the primary air pipe (2) is sleeved outside the gas pipe (1), wherein a primary air inlet (23) is provided on the side of the primary air pipe (2), and an external annular channel (22) is formed between the primary air pipe (2) and the gas pipe (1), wherein the primary air swirl blade (21) is arranged in the external annular channel (22).

6. The adjustable swirl blade lower burner of the annular sleeve kiln according to claim 5 is characterized in that: The rotation angle of the gas swirl blade (11) is 30° to 55°.

7. The adjustable swirl blade lower burner of the annular sleeve kiln according to claim 6 is characterized in that: The rotation angle of the gas swirl blade (11) is 40° to 45°.

8. The adjustable swirl blade lower burner of the annular sleeve kiln according to claim 5 is characterized in that: The rotation angle of the primary air swirl blade (21) is 30°.

9. The adjustable swirl blade lower burner of the annular sleeve kiln according to claim 5, characterized in that: It also includes a volute (4) and a combustion chamber (5), wherein the outlets of the primary air duct (2) and the gas pipe (1) are connected to the inlet of the expansion port (3), the outlet of the expansion port (3) is connected to the inlet of the volute (4), a secondary air inlet (41) is provided on the side of the volute (4), and the outlet of the volute (4) is connected to the combustion chamber (5).

10. An annular sleeve kiln, comprising the annular sleeve kiln adjustable swirl blade lower burner according to any one of claims 5 to 9, characterized in that: The annular sleeve kiln comprises an outer sleeve and an inner sleeve, wherein the outer sleeve comprises a lower outer sleeve, and the inner sleeve comprises a lower inner sleeve. The lower burner is located between the lower outer sleeve and the lower inner sleeve of the annular sleeve kiln and is evenly distributed along the circumference.

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