Center blanking whirling material flow heat exchange flue and heat exchange method thereof

Abstract

The invention relates to the technical field of the building material industry, aims to solve the problems of material scattering, poor heat exchange efficiency, low flue gas waste heat recovery and utilization rate, high clinker sintering heat consumption and incapability of realizing energy conservation, consumption reduction, emission reduction and efficiency improvement in the prior art, and provides a center blanking whirling material flow heat exchange flue and a heat exchange method thereof. Comprising a first cyclone, a second cyclone and a third cyclone which are connected in series; each of the first cyclone, the second cyclone and the third cyclone is provided with a cone part and a heat exchange flue; the cone parts of the first cyclone cylinder, the second cyclone cylinder and the third cyclone cylinder are connected with discharging pipes, sleeves are arranged in heat exchange flues of the first cyclone cylinder, the second cyclone cylinder and the third cyclone cylinder, the discharging pipes are arranged in the sleeves, materials directly enter heat exchange areas of the heat exchange flues from the discharging pipes, center blooming is achieved, and material-gas mixing and heat exchange are completed. The invention has the beneficial effects of good scattering effect, high heat exchange efficiency, high flue gas waste heat utilization rate, low clinker firing heat consumption, energy conservation, consumption reduction, emission reduction and efficiency improvement.

Description

Technical Field

[0001] The invention relates to the technical field of building materials industry, and in particular to a central material discharge swirling material flow heat exchange flue and a heat exchange method thereof. Background Art

[0002] In the new dry cement production line, a preheater is often used to preheat and predecompose the fine powder raw material. The conventional preheater is composed of a multi-stage cyclone, a heat exchange flue, a discharge pipe, an expansion joint, a flap valve, a spreading box and other parts; the material separated in the upper cyclone flows through the flap valve, the discharge pipe and the spreading box into the heat exchange flue of the next stage, where it is mixed and heat exchanged with the high-temperature flue gas, and enters the next cyclone together with the high-temperature flue gas rising in the heat exchange flue, thus completing multiple preheating and material-gas separation, and achieving the purpose of gas-solid heat exchange and preheating and predecomposition; in the heat exchange flue, the average cross-sectional wind speed of the high-temperature gas is about 16m / s, but due to the centrifugal force of the next cyclone, the high-temperature gas in the heat exchange flue rises in a vortex, that is, the wind speed in the central area is low, and the wind speed in the outer circumference area is high. After separation in the upper cyclone, the fine powder material enters the flap valve through the discharge pipe. After the material accumulates a certain weight at the flap valve, the valve The plate valve opens automatically. At this time, the high-speed hot air in the outer circumference area will flow into the other cyclones along this channel, affecting the separation and heat exchange effects of the system. These two effects are the most important indicators of the preheater. Therefore, it is necessary to cooperate with a micro-motion flap valve with higher design requirements to reduce internal cross-wind. However, in the existing actual production, there is still a lot of internal cross-wind. When the material enters the next section of the material pipe, the flap valve automatically closes and locks the wind; the falling material forms a large kinetic energy in a certain length of the subsequent material pipe, and then enters the spreading box. Under the action of kinetic energy and the spreading box, the fine powder material is dispersed as much as possible into the heat exchange flue, and the downward diving material is gradually decelerated under the drive of a higher rising wind speed, and it is necessary to complete the rise before reaching the inner cylinder in the next stage cyclone, otherwise part of the material will short-circuit and directly enter the next stage cyclone. This part of the short-circuited material has not completed the heat exchange, which will affect the effect of preheating and predecomposition, and even affect the production of the entire system.

[0003] Therefore, in the original preheater, the flap valve, the length and angle of the discharge pipe, the form and layout of the spreading box, etc. have a great influence on the heat exchange effect of the material; if the location of the spreading box is too close to the next-stage cyclone, the material will be at risk of short-circuiting into the next-stage cyclone; if the location of the spreading box is too far from the next-stage cyclone, the height of the heat exchange flue will be relatively shortened, reducing the heat exchange time and path, and will also affect the heat exchange effect; therefore, the layout of the spreading box has a large and sensitive influence on the spreading effect and heat exchange; in addition, the structure of the spreading box itself also has a great influence on the spreading and heat exchange, because the better the dispersion effect of the spreading box on fine powder materials, the larger the contact area between the material and the high-temperature flue gas. The higher the convective heat transfer coefficient, the higher the heat transfer efficiency, the more waste heat is recovered, and ultimately the lower the heat consumption of clinker burning. In order to enhance the spreading effect, many manufacturers have designed different types of spreading boxes. However, these spreading methods have certain defects in principle, because they can only load and unload materials on the side walls of the heat exchange flue, and there are few feeding points, resulting in a longer mixing time of fine powder materials and high-temperature flue gas, so the spreading effect is general. In addition, the subsequent heat exchange time is also reduced. If the heat exchange time is increased by raising the heat exchange flue, the height and investment cost of the entire preheater will be increased accordingly, which will in turn aggravate the heat exchange effect in the high-temperature flue, thereby affecting the preheating and predecomposition functions of the preheater, and also increasing the heat consumption of cement clinker burning in disguise.

[0004] In summary, under the increasingly severe situation of overcapacity in cement production, current technology makes it difficult to improve the spreading effect and heat exchange efficiency, resulting in difficulty in efficiently recovering waste heat in flue gas, high heat consumption in clinker burning, and the inability to achieve the goals of energy conservation and consumption reduction, and emission reduction and efficiency improvement. Summary of the invention

[0005] The present invention aims to provide a central feeding swirling material flow heat exchange flue and a heat exchange method thereof, so as to solve the problems in the prior art of poor material spreading effect, low heat exchange efficiency, low flue gas waste heat recovery rate, high heat consumption for clinker burning, inability to achieve energy saving and consumption reduction, and inability to achieve emission reduction and efficiency improvement.

[0006] The embodiment of the present invention is achieved as follows:

[0007] The embodiment of the present invention provides a central unloading cyclone flow heat exchange flue, which includes a first cyclone cylinder, a second cyclone cylinder and a third cyclone cylinder;

[0008] One end of the first cyclone barrel close to the second cyclone barrel is connected to the second cyclone barrel, and one end of the second cyclone barrel close to the third cyclone barrel is connected to the second cyclone barrel;

[0009] The first cyclone, the second cyclone and the third cyclone all have a cone and a heat exchange flue, the cone of the first cyclone is connected to the heat exchange flue of the second cyclone, the heat exchange flue of the first cyclone is connected to the second cyclone, the cone of the second cyclone is connected to the heat exchange flue of the third cyclone, and the heat exchange flue of the second cyclone is connected to the third cyclone;

[0010] The bottom ends of the vertebral bodies of the first cyclone, the second cyclone and the third cyclone are all fixedly connected with a feed pipe, and the heat exchange flue of the first cyclone, the second cyclone and the third cyclone are all provided with a sleeve inside, and one end of the feed pipe close to the sleeve is inserted into the interior of the sleeve.

[0011] The central-discharging swirling material flow heat exchange flue disclosed in the present embodiment changes the technical route of spreading materials on the side walls into the technical route of spreading materials in the center. The materials directly enter the central area of ​​the heat exchange flue of the second cyclone from the above-mentioned discharge pipe, realizing central blooming, and better completing the material-gas mixing and heat exchange. As a result, the central-discharging swirling material flow heat exchange flue has good material spreading effect, high heat exchange efficiency, efficient recovery of waste heat in the flue gas, low heat consumption for burning clinker, and can achieve the beneficial effects of energy saving, consumption reduction, emission reduction and efficiency improvement.

[0012] Optionally, the feed tube and the sleeve are clearance-matched with each other.

[0013] Such an arrangement can control the different cross-sectional areas above and below the casing, thereby controlling the gas flow rate in the casing, and effectively controlling the wind speed difference inside and outside the casing, that is, the wind speed inside the casing is low and the wind speed outside the casing is high, and at the same time, it is convenient for a part of the material gas to rise from between the lower feeding pipe and the casing to the second cyclone to complete another heat exchange and separation cycle.

[0014] Optionally, a guide support plate is fixedly connected to the outer wall of the sleeve in radial direction, and one end of the guide support plate away from the sleeve is fixedly connected to the inner wall of the heat exchange flue.

[0015] With such arrangement, the guide support plate has the function of fixing the sleeve and also has a certain shaping and guiding function, so that the gas flow field distribution in the area between the sleeve and the heat exchange flue is more uniform and the heat exchange is better.

[0016] Optionally: one end of the sleeve close to the feed tube is fixedly connected with a tapered tube, the feed tube passes through the tapered tube and is inserted into the sleeve, and the tapered tube and the feed tube are clearance-matched with each other.

[0017] In this way, the conical tube can limit the space between the top of the sleeve and the feed pipe, avoiding the passage of excessive material-gas mixture, effectively prolonging the time of fine powder material in the sleeve, thereby prolonging the heat exchange time and enhancing the heat exchange effect between the fine powder material and the high-temperature flue gas in the sleeve.

[0018] Optionally: an expansion joint is provided at one end of the discharge pipe close to the vertebral body of the first cyclone, the expansion joint is connected to the bottom end of the vertebral body of the first cyclone, a flap valve is provided between the expansion joint and the discharge pipe, and two ends of the flap valve are respectively connected to the expansion joint and the discharge pipe;

[0019] The feed pipe passes through the top surface of the heat exchange flue and is placed inside the heat exchange flue. The connection between the feed pipe and the heat exchange flue is sealed and connected to each other.

[0020] With such arrangement, the expansion joint can absorb the thermal expansion between the upper and lower cyclones, and the flap valve automatically opens when a certain weight of material is accumulated at the flap valve, and closes and locks the wind when the material enters the next section of the material pipe. The joint between the discharge pipe and the heat exchange flue is sealed to effectively prevent gas leakage out of the flue, thereby preventing pollution of the environment around the equipment and ensuring the health of the staff.

[0021] Optionally: the internal wind speed of the above-mentioned casing is 2m / s to 8m / s.

[0022] With such arrangement, the wind speed of 2m / s to 8m / s is not enough to lift the sliding fine powder material, so that the fine powder material gradually decelerates and slides slowly in the above-mentioned casing, and the fine powder material and the high-temperature flue gas complete the first stage of heat exchange, thereby extending the heat exchange time between the fine powder material and the high-temperature flue gas and enhancing the heat exchange effect between the fine powder material and the high-temperature flue gas in the above-mentioned casing.

[0023] Optionally: the wind speed in the area between the above-mentioned sleeve and the above-mentioned heat exchange flue is greater than 16m / s.

[0024] With such an arrangement, a wind speed of 16 m / s can effectively lift the material, prevent the material from short-circuiting and directly entering the third cyclone, and help the material to move upward in the opposite direction, re-enter the heat exchange area of ​​the above-mentioned casing and the above-mentioned heat exchange flue, and finally the material gas moves to the above-mentioned second cyclone to complete another heat exchange and separation cycle.

[0025] In one implementation of this embodiment: a heat exchange method for a central unloading cyclonic material flow heat exchange flue is also provided, firstly, the centrifugal force of the third cyclone acts to separate the gas flow rate in the heat exchange flue of the second cyclone, the wind speed inside the sleeve of the second cyclone is low, and the wind speed in the outer circumferential area of ​​the sleeve is high, and in addition, the conical tube and the unloading tube are gap-matched, so that the upper and lower cross-sectional areas of the sleeve are different, thereby controlling the gas flow rate in the sleeve;

[0026] Secondly, the first cyclone produces material-gas separation under the action of centrifugal force, and the material falls into the vertebral body of the first cyclone. The fine powder material slides into the discharge pipe through the expansion joint and the flap valve under the action of gravity and impact force. The fine powder material in the discharge pipe slides into the casing under the action of gravity and impact force. Since the wind speed in the casing is low and insufficient to hold up the sliding fine powder material, the fine powder material will not directly turn and short-circuit into the second cyclone. The fine powder material gradually decelerates and slides slowly in the casing. The deceleration and sliding of the fine powder material prolongs the heat exchange time of the fine powder material and enhances the heat exchange effect between the fine powder material and the high-temperature flue gas in the casing.

[0027] Finally, after the fine powder material enters the above-mentioned heat exchange flue of the above-mentioned second cyclone, due to the deceleration and dispersion of the fine powder material in the above-mentioned sleeve and the superimposed effect of the high wind speed in the above-mentioned heat exchange flue of the above-mentioned second cyclone, the fine powder material is quickly mixed with the high-speed flue gas, achieving the effect of efficient center blooming dispersion of the material, and then the fine powder material enters the high-speed area between the above-mentioned sleeve and the above-mentioned heat exchange flue, and the high-temperature gas rising through the above-mentioned third cyclone blows the mixed gas of the fine powder material and the high-speed flue gas into the above-mentioned second cyclone to complete another heat exchange and separation cycle.

[0028] Optionally, the material is dispersed and heat-exchanged in the first step in the low wind speed area inside the casing, and the material is dispersed and heat-exchanged in the second step in the high wind speed area at the bottom of the casing and around the casing.

[0029] With such arrangement, generally speaking, the fine powder material passes through two heat exchange paths inside and outside the above-mentioned casing, namely the U-shaped cyclonic heat exchange path. Compared with the existing technical route, the heat exchange path and time of the fine powder material are nearly doubled.

[0030] Optionally: the sleeve between the first cyclone tube, the second cyclone tube, the third cyclone tube and the heat exchange flue is located in a central area with low wind speed.

[0031] With such arrangement, the air volume passing through the above-mentioned sleeve, the above-mentioned discharge pipe and the above-mentioned flap valve will be greatly reduced, which can enhance the separation and heat exchange effects and help improve the power consumption and heat consumption of the firing system.

[0032] Based on the above description, the central feeding swirling material flow heat exchange flue and the heat exchange method disclosed in the present invention have good material spreading effect, high heat exchange efficiency, efficient recovery of waste heat in flue gas, low heat consumption for burning clinker, and can achieve the beneficial effects of energy saving, consumption reduction, emission reduction and efficiency improvement. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0034] Figure 1 It is a schematic diagram of the installation of a central unloading cyclonic material flow heat exchange flue in an embodiment of the present invention;

[0035] Figure 2 This is a schematic structural diagram of a centrally discharged cyclonic flow heat exchange flue in an embodiment of the present invention;

[0036] Figure 3 For the embodiment of the present invention Figure 2 The enlarged schematic diagram at A in the middle;

[0037] Figure 4 This is a wind velocity flow field diagram of a central unloading swirling material flow heat exchange flue in an embodiment of the present invention;

[0038] Figure 5 It is a flow velocity trajectory diagram of a centrally discharged swirling material flow heat exchange flue in an embodiment of the present invention.

[0039] Icons: 1-first cyclone, 2-second cyclone, 3-third cyclone, 4-vertebral body, 5-heat exchange flue, 6-down pipe, 7-casing, 8-guide support plate, 9-conical pipe, 10-expansion joint, 11-flap valve, 12-material flow, 13-spiral airflow, 14-material gas. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0041] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] Example

[0043] See also Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 This embodiment provides a central unloading cyclone heat exchange flue, comprising a first cyclone 1, a second cyclone 2 and a third cyclone 3;

[0044] One end of the first cyclone tube 1 close to the second cyclone tube 2 is connected to the second cyclone tube 2, and one end of the second cyclone tube 2 close to the third cyclone tube 3 is connected to the second cyclone tube 2;

[0045] The first cyclone 1, the second cyclone 2 and the third cyclone 3 all have a cone 4 and a heat exchange flue 5. The cone 4 of the first cyclone 1 is connected to the heat exchange flue 5 of the second cyclone 2, the heat exchange flue 5 of the first cyclone 1 is connected to the second cyclone 2, the cone 4 of the second cyclone 2 is connected to the heat exchange flue 5 of the third cyclone 3, and the heat exchange flue 5 of the second cyclone 2 is connected to the third cyclone 3;

[0046] The bottom ends of the vertebral bodies 4 of the first cyclone 1, the second cyclone 2 and the third cyclone 3 are fixedly connected with a feed pipe 6, and the heat exchange flue 5 of the first cyclone 1, the second cyclone 2 and the third cyclone 3 are internally provided with a sleeve 7, and the end of the feed pipe 6 close to the sleeve 7 is inserted into the interior of the sleeve 7.

[0047] The central-discharging swirling flow heat exchange flue disclosed in the present embodiment changes the technical route of spreading materials on the side walls into the technical route of spreading materials in the center. The materials directly enter the central area of ​​the heat exchange flue 5 of the second cyclone 2 from the discharge pipe 6, realizing central blooming, and better completing the material-gas mixing and heat exchange. As a result, the central-discharging swirling flow heat exchange flue has good material spreading effect, high heat exchange efficiency, efficient recovery of waste heat in the flue gas, low heat consumption for burning clinker, and can achieve the beneficial effects of energy saving, consumption reduction, emission reduction and efficiency improvement.

[0048] In this embodiment, the arrangement of the first cyclone barrel 1, the second cyclone barrel 2 and the third cyclone barrel 3 is not limited in this technical solution, and several cyclones may be arranged in series.

[0049] See also Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 The feed pipe 6 and the sleeve 7 are fitted with each other in a clearance, so that the different cross-sectional areas of the sleeve 7 can be controlled, and then the gas flow rate in the sleeve 7 can be controlled, and the wind speed difference inside and outside the sleeve 7 can be effectively controlled, that is, the wind speed inside the sleeve 7 is low and the wind speed outside the sleeve 7 is high. At the same time, it is convenient for a part of the material gas to rise from between the feed pipe 6 and the sleeve 7 to the second cyclone 2 to complete another heat exchange and separation cycle.

[0050] A guide support plate 8 is fixedly connected to the outer wall of the sleeve 7 in the radial direction. The end of the guide support plate 8 away from the sleeve 7 is fixedly connected to the inner wall of the heat exchange flue 5. The guide support plate 8 has the function of fixing the sleeve 7 and also has a certain shaping and guiding function, so that the gas flow field distribution in the area between the sleeve 7 and the heat exchange flue 5 is more uniform and the heat exchange is better.

[0051] A conical tube 9 is fixedly connected to one end of the sleeve 7 near the discharge pipe 6. The discharge pipe 6 passes through the conical tube 9 and is inserted into the sleeve 7. The conical tube 9 and the discharge pipe 6 are matched with each other with a clearance. The conical tube 9 can limit the space between the top of the sleeve 7 and the discharge pipe 6 to avoid excessive passage of the material-gas mixture, effectively prolonging the time of the fine powder material in the sleeve 7, thereby prolonging the heat exchange time and enhancing the heat exchange effect between the fine powder material and the high-temperature flue gas in the sleeve 7.

[0052] See also Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 An expansion joint 10 is provided at one end of the discharge pipe 6 close to the vertebral body 4 of the first cyclone 1, and the expansion joint 10 is connected to the bottom end of the vertebral body 4 of a cyclone. A flap valve 11 is provided between the expansion joint 10 and the discharge pipe 6, and the two ends of the flap valve 11 are respectively connected to the expansion joint 10 and the discharge pipe 6; the discharge pipe 6 passes through the top surface of the heat exchange flue 5 and is placed in the interior of the heat exchange flue 5. The connection between the discharge pipe 6 and the heat exchange flue 5 is sealed and connected to each other. The expansion joint 10 can absorb the thermal expansion between the upper and lower cyclones, and the function of the flap valve 11 is that after a certain weight of material is accumulated at the flap valve 11, the flap valve 11 automatically opens. When the material enters the next section of the material pipe, the flap valve 11 automatically closes and locks the wind. The connection between the discharge pipe 6 and the heat exchange flue 5 is sealed and connected to each other, which effectively avoids the leakage of material gas out of the flue, prevents pollution of the environment around the equipment, and ensures the health of the staff.

[0053] The internal wind speed of the sleeve 7 is 2m / s~8m / s. The wind speed of 2m / s~8m / s is not enough to lift the sliding fine powder material, so that the fine powder material gradually slows down and slides slowly in the sleeve 7. The fine powder material and the high-temperature flue gas complete the first stage of heat exchange, thereby extending the heat exchange time between the fine powder material and the high-temperature flue gas and enhancing the heat exchange effect between the fine powder material and the high-temperature flue gas in the sleeve 7.

[0054] The wind speed in the area between the sleeve 7 and the heat exchange flue 5 is greater than 16 m / s. The wind speed of 16 m / s can effectively lift the material, prevent the material from short-circuiting and directly entering the third cyclone 3, and help the material to move upward in the opposite direction, re-enter the heat exchange area of ​​the sleeve 7 and the heat exchange flue 5, and finally the material gas moves to the second cyclone 2 to complete another heat exchange and separation cycle.

[0055] See also Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 In this embodiment, the central material discharge does not require a material spreading box, and there is no need to consider the sensitive effects of the discharge pipe 6 and the flap valve 11 on the material spreading and heat exchange, which is more flexible and reliable in actual layout and operation.

[0056] In this embodiment, in the prior art route, the material discharge is located in a high wind speed area, and the cross-flow of the material is relatively large. The material discharge pipe 6 of this solution is in the low wind speed area in the center. Relatively speaking, in principle, the cross-flow of the material spread in the center will be greatly reduced, and therefore the dependence on the wind locking effect of the micro-motion flap valve 11 can be greatly reduced.

[0057] In this embodiment, the material discharge point directly enters the inner center of the heat exchange flue 5 through the material discharge pipe 6 to spread the material. Spreading the material in the protruding center can better disperse the mixing and homogenizing effect.

[0058] See also Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 In this embodiment, by designing and controlling the diameters of the feed pipe 6, the tapered pipe 9, the sleeve 7 and the heat exchange flue 5, and the effect of the cyclone separation, a wind speed of 2m / s to 8m / s in the central area and a wind speed distribution of more than 16m / s in the circumferential area around the outer side of the sleeve 7 are obtained. The specific wind speed can be designed in the design stage, and then the feed pipe 6, the tapered pipe 9, the sleeve 7 and the heat exchange flue 5 of the corresponding diameter are manufactured.

[0059] In this embodiment, the feed pipe 6, the tapered pipe 9, the sleeve 7 and the guide support plate 8 can be made of heat-resistant steel. Considering some wear, a certain thickness of wear-resistant ramming material or wear-resistant ceramics can also be applied.

[0060] See also Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5The specific working principle of a central unloading cyclone flow heat exchange flue is as follows: the first cyclone 1 produces material-gas separation under the action of centrifugal force. Due to the central unloading, the vertebral body 4 of the first cyclone 1 is mostly a positive cone or a smaller eccentric cone. The material directly enters the central unloading cyclone flow heat exchange flue 5 of the second cyclone 2 through the expansion joint 10, the universal flap valve 11 and the unloading pipe 6. There is no need for a material spreading box, and the arrangement of the unloading pipe 6 is more concise; the material enters the casing 7 through the new unloading pipe 6. Due to the effect of the diameter of the conical pipe 9 and the unloading pipe 6, the average wind speed in the casing 7 is controlled to 2m / s to 8m / s (this wind speed is not enough to make the material short-circuit and directly enter the next stage of cyclone). The material slowly descends in the casing 7 and completes the first stage of heat exchange with the high-temperature flue gas. The decelerated descent can increase the heat exchange time and improve the heat exchange effect. Since the wind speed in the casing 7 is low, about 2m / s to 8m / s, the wind speed in the area between the casing 7 and the heat exchange flue 5 is high, greater than 16m / s. This wind speed distribution and material flow direction are reasonable. In addition, at the entrance of the heat exchange flue 5, due to the effect of the variable cross-section, the wind speed here becomes relatively high. This local high wind speed can effectively hold up the material and prevent the material from short-circuiting and directly entering the third cyclone 3, which helps the material to move upward in the opposite direction and re-enter the heat exchange area of ​​the casing 7 and the heat exchange flue 5.

[0061] See also Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 In one implementation of the present embodiment: a heat exchange method for a central unloading cyclonic material flow heat exchange flue is also provided. First, the centrifugal force of the third cyclone 3 causes the gas flow rate in the heat exchange flue 5 of the second cyclone 2 to separate. The wind speed inside the sleeve 7 of the second cyclone 2 is low, and the wind speed in the outer circumferential area of ​​the sleeve 7 is high. In addition, the conical tube 9 and the unloading tube 6 are gap-matched, so that the upper and lower cross-sectional areas of the sleeve 7 are different, thereby controlling the gas flow rate in the sleeve 7;

[0062] Secondly, the first cyclone 1 produces material-gas separation under the action of centrifugal force, and the material falls into the vertebral body 4 of the first cyclone 1. The fine powder material slides into the discharge pipe 6 through the expansion joint 10 and the flap valve 11 under the action of gravity and impact force. The fine powder material in the discharge pipe 6 slides into the sleeve 7 under the action of gravity and impact force. Since the wind speed in the sleeve 7 is low and insufficient to hold up the sliding fine powder material, the fine powder material will not directly turn and short-circuit into the second cyclone 2. The fine powder material gradually decelerates and slowly slides down in the sleeve 7. The deceleration and sliding of the fine powder material prolongs the heat exchange time of the fine powder material and enhances the heat exchange effect between the fine powder material and the high-temperature flue gas in the sleeve 7.

[0063] Finally, after the fine powder material enters the heat exchange flue 5 of the second cyclone 2, due to the deceleration and dispersion of the fine powder material in the sleeve and the superimposed effect of the high wind speed in the heat exchange flue 5 of the second cyclone 2, the fine powder material is quickly mixed with the high-speed flue gas, achieving the effect of efficient center blooming dispersion of the material, and then the fine powder material enters the high-speed area between the sleeve 7 and the heat exchange flue 5, and the high-temperature gas rising through the third cyclone 3 blows the mixed gas of the fine powder material and the high-speed flue gas into the second cyclone 2 to complete another heat exchange and separation cycle.

[0064] The material realizes the first step of dispersion and heat exchange in the low wind speed area inside the casing 7, and the second step of dispersion and heat exchange is realized in the high wind speed area at the bottom of the casing 7 and around the outer periphery of the casing 7. Generally speaking, the fine powder material passes through two heat exchange paths inside and outside the casing 7, namely the U-shaped cyclonic heat exchange path. Compared with the existing technical route, the heat exchange path and time of the fine powder material are nearly doubled.

[0065] The sleeve 7 between the first cyclone 1 or the second cyclone 2 or the third cyclone 3 and the heat exchange flue 5 is in the central area of ​​low wind speed, so that the amount of wind passing through the sleeve 7, the discharge pipe 6 and the flap valve will be greatly reduced, which can enhance the separation and heat exchange effects and help improve the power consumption and heat consumption of the firing system.

[0066] See also Figure 1 and Figure 2 In this embodiment, the technical route of central spreading can double the heat exchange time and heat exchange path, enhance the spreading effect of uniform dispersion between gas and solid, and greatly improve the effect of gas-solid heat exchange; greatly improve the heat exchange efficiency between materials and high-temperature flue gas, and efficiently recover the waste heat in the flue gas; after the central material discharge vortex material flow heat exchange, the flue gas temperature after the waste heat is recovered is 35°C lower than that of the previous one, and the heat consumption of cement clinker burning can reduce the standard coal consumption by 2kg.ce / kg.clk to 3kg.ce / kg.clk; this scheme is conducive to reducing the heat consumption and power consumption of the burning system.

[0067] See also Figure 1 , Figure 2 and Figure 3 The downward arrow inside the feed pipe 6 represents the material flow 12. The material flow 12 enters the sleeve 7 through the feed pipe 6. The material flow 12 in the sleeve 7 continues to flow downward under the action of gravity. There is an upward spiral airflow 13 inside the cyclone of the next level. The spiral airflow 13 will lift the material flow 12 at the bottom end of the sleeve 7. A part of the material flow 12 and the spiral airflow 13 are mixed into a material gas 14 which moves upward along the inside of the sleeve 7, and flows into the heat exchange flue 5 through the gap between the sleeve 7 and the feed pipe 6 to enter the cyclone of the previous level, while most of the material gas 14 flows into the cyclone of the previous level along the gap between the sleeve 7 and the heat exchange flue 5, so as to circulate back and forth.

[0068] See also Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 ,exist Figure 4 In the figure, the wind speed inside the sleeve 7 is low, and the wind speed in the gap between the sleeve 7 and the heat exchange flue 5 is high. This flow field analysis confirms the above design and analysis, that is, the wind speed distribution and the material flow direction are reasonable. In addition, at the lower end of the heat exchange flue 5, due to the effect of the variable cross-section, the wind speed here becomes relatively high. This local high wind speed can effectively hold up the material, prevent the material from short-circuiting and directly entering the third cyclone 3, and help the material to move upward in the opposite direction and re-enter the sleeve 7 and the heat exchange area between the sleeve 7 and the heat exchange flue 5; Figure 5 It can be clearly seen that the wind speed inside the casing 7 is low, while the wind speed in other areas outside the casing is high and presents a spiral rising state.

[0069] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A central feeding cyclonic flow heat exchange flue, characterized in that: It comprises a first cyclone barrel (1), a second cyclone barrel (2) and a third cyclone barrel (3); The first cyclone (1), the second cyclone (2) and the third cyclone (3) all have a cone (4) and a heat exchange flue (5); The bottom ends of the vertebral bodies (4) of the first cyclone (1), the second cyclone (2) and the third cyclone (3) are all fixedly connected with a feed pipe (6); the heat exchange flue (5) of the first cyclone (1), the second cyclone (2) and the third cyclone (3) are all provided with a sleeve (7); one end of the feed pipe (6) close to the sleeve (7) is inserted into the interior of the sleeve (7).

2. A central feeding swirling flow heat exchange flue according to claim 1, characterized in that: The feed tube (6) and the sleeve (7) are clearance-matched with each other.

3. The central feeding swirling flow heat exchange flue according to claim 1, characterized in that: A guide support plate (8) is fixedly connected to the outer wall of the sleeve (7) in the radial direction, and one end of the guide support plate (8) away from the sleeve (7) is fixedly connected to the inner wall of the heat exchange flue (5).

4. The central feeding swirling flow heat exchange flue according to claim 1, characterized in that: A conical tube (9) is fixedly connected to one end of the sleeve (7) close to the discharge tube (6); the discharge tube (6) passes through the conical tube (9) and is inserted into the sleeve (7); the conical tube (9) and the discharge tube (6) are clearance-matched with each other.

5. The central feeding swirling flow heat exchange flue according to claim 1, characterized in that: An expansion joint (10) is provided at one end of the discharge pipe (6) close to the vertebral body (4) of the first cyclone (1), and the expansion joint (10) is connected to the bottom end of the vertebral body (4) of the first cyclone. A flap valve (11) is provided between the expansion joint (10) and the discharge pipe (6), and two ends of the flap valve (11) are respectively connected to the expansion joint (10) and the discharge pipe (6); The feed pipe (6) passes through the top surface of the heat exchange flue (5) and is placed inside the heat exchange flue (5). The connection between the feed pipe (6) and the heat exchange flue (5) is sealed to each other.

6. The central feeding swirling flow heat exchange flue according to claim 1, characterized in that: The internal wind speed of the casing (7) is 2m / s to 8m / s.

7. The central feeding swirling flow heat exchange flue according to claim 1, characterized in that: The wind speed in the area between the sleeve (7) and the heat exchange flue (5) is greater than 16 m / s.

8. A heat exchange method using a central feeding swirling flow heat exchange flue as claimed in any one of claims 1 to 7, characterized in that: Firstly, due to the centrifugal force of the third cyclone (3), the gas flow rate in the heat exchange flue (5) of the second cyclone (2) is separated, the wind speed inside the sleeve (7) of the second cyclone (2) is low, and the wind speed in the outer circumferential area of ​​the sleeve (7) is high. In addition, the conical tube (9) and the discharge tube (6) are clearance-matched, so that the upper and lower cross-sectional areas of the sleeve (7) are different, thereby controlling the gas flow rate in the sleeve (7); Secondly, the first cyclone (1) produces material-gas separation under the action of centrifugal force, and the material falls into the vertebral body (4) of the first cyclone (1). The fine powder material slides into the discharge pipe (6) through the expansion joint (10) and the flap valve (11) under the action of gravity and impact force. The fine powder material in the discharge pipe (6) slides into the sleeve (7) under the action of gravity and impact force. Since the wind speed in the sleeve (7) is low and insufficient to lift the sliding fine powder material, the fine powder material will not directly turn and short-circuit into the second cyclone (2). The fine powder material gradually decelerates and slowly slides down in the sleeve (7). The deceleration and sliding of the fine powder material prolongs the heat exchange time of the fine powder material and enhances the heat exchange effect between the fine powder material and the high-temperature flue gas in the sleeve (7); Finally, after the fine powder material enters the heat exchange flue (5) of the second cyclone (2), due to the deceleration and dispersion of the fine powder material in the sleeve and the superimposed effect of the high wind speed in the heat exchange flue (5) of the second cyclone (2), the fine powder material is quickly mixed with the high wind speed flue gas, achieving an efficient center blooming dispersion effect of the material, and then the fine powder material enters the high wind speed area between the sleeve (7) and the heat exchange flue (5), and the high-temperature gas rising from the third cyclone (3) blows the mixed gas of the fine powder material and the high wind speed flue gas into the second cyclone (2) to complete another heat exchange and separation cycle.

9. A heat exchange method for a centrally discharged swirling material flow heat exchange flue according to claim 8, characterized in that: The material achieves the first step of dispersion and heat exchange in the low wind speed area inside the casing (7), and the material achieves the second step of dispersion and heat exchange in the high wind speed area at the bottom of the casing (7) and the outer periphery of the casing (7).

10. A heat exchange method for a centrally discharged swirling material flow heat exchange flue according to claim 9, characterized in that: The sleeve (7) between the first cyclone (1) or the second cyclone (2) or the third cyclone (3) and the heat exchange flue (5) is located in a central area with low wind speed.

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