Composite waste heat recovery structure of sintering rotary furnace

Abstract

The invention relates to the technical field of waste heat recovery equipment, in particular to a sintering rotary furnace waste heat composite recovery structure which comprises a rotary furnace body, a boiler body, an energy saver and a flue gas treatment device. The two ends of the economizer are connected with a boiler body flue and the flue gas treatment device respectively, the flue gas treatment device comprises a compression cavity, a piston, a driving device, a water outlet, an exhaust port, a vortex tube and a recovery cavity, the compression cavity is communicated with the economizer through a throat pipe, the piston is located in the compression cavity and forms a moving pair with the compression cavity, and the driving device can drive the piston to move. The water outlet and the exhaust port are communicated with the compression cavity, the recovery cavity surrounds the outside of the compression cavity and is communicated with the hot air outlet of the vortex tube, four-time waste heat recovery is achieved through mutual cooperation of all the components, and the waste heat recovery efficiency is high.

Description

Technical Field

[0001] The invention relates to the field of rotary kiln waste heat recovery equipment, and in particular to a sintering rotary kiln waste heat composite recovery structure. Background Art

[0002] A sintering rotary kiln (Fritting furnace) refers to a furnace-like device in existing technology that achieves powder sintering through heating. To reduce air pollution, existing technologies often use clean energy such as natural gas, hydrogen, or biogas as fuel. The main components of its combustion flue gas are unsaturated water vapor and high-temperature air (CO2), which is environmentally friendly.

[0003] The common method for recovering the waste heat of high-temperature flue gas from a rotary furnace is to pass it through a heat exchanger and then discharge it. After being recovered through the heat exchanger, the flue gas still has a relatively high temperature of up to 150°C, and the waste heat utilization rate is less than 60%. The heat recovery efficiency is not high. The purpose of the present invention is to improve the waste heat recovery structure of the existing rotary furnace to improve the waste heat utilization efficiency of the rotary furnace flue gas. Summary of the Invention

[0004] The object of the present invention is to provide a composite waste heat recovery structure for a sintering rotary kiln to solve the problems mentioned in the background technology.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solution: comprising a rotary furnace body, a boiler body, an economizer and a flue gas treatment device, wherein the exhaust pipe of the rotary furnace body is connected to the furnace of the boiler body through a connecting pipe, and the high-temperature flue gas generated by the combustion of the rotary furnace body is discharged into the boiler body through the connecting pipe for the first waste heat recovery, which is directly used for the boiler body to produce steam or hot water. The rotary furnace body here specifically refers to a gas-fired rotary furnace using natural gas, hydrogen, biogas and other fuels as raw materials. The two ends of the economizer are respectively connected to the flue of the boiler body and the flue gas treatment device. The economizer refers to a device in the field provided at the flue of the boiler body for recovering the waste heat of the flue gas. It belongs to the existing technical content and its structure and working principle are known to those skilled in the art. Therefore, its specific structure and working principle will not be further described. It is used for performing a second waste heat recovery on the flue gas discharged from the boiler body; The flue gas treatment device includes a compression chamber, a piston, a driving device, a drain port, an exhaust port, a vortex tube, and a recovery chamber. The compression chamber is connected to the economizer through a throat pipe. The piston is located in the compression chamber and matches the compression chamber to form a moving pair along the length direction of the compression chamber. The driving device can drive the piston to move. The drain port is located at the bottom end of the compression chamber and is connected to the compression chamber. A first solenoid valve is installed on the drain port. By opening the first solenoid valve, liquefied water generated during the steam compression process is discharged. The exhaust port is located on the side of the compression chamber and is connected to the compression chamber. A second solenoid valve is installed on the exhaust port. The flue gas whose waste heat is recovered by the economizer for the second time is subjected to a third waste heat recovery through the flue gas treatment device. The air inlet of the vortex tube is connected to the second solenoid valve, and the vortex tube cooperates with the recovery chamber to recover the high-pressure flue gas recovered by the flue gas treatment device four times; The recovery chamber is filled with a heat-conducting medium, which surrounds the outside of the compression chamber. A heat exchange tube is arranged in the recovery chamber, and one end of the heat exchange tube is connected to the hot gas outlet of the vortex tube. The specific heat-conducting medium to be used can be selected by technicians according to actual needs, such as heat-conducting oil, water, etc.

[0006] In order to optimize the above technical solution, further measures are taken as follows: the driving device is an oil cylinder, which is fixedly connected to the boiler body through a fixed frame, and the oil cylinders are symmetrically distributed on both sides of the recovery chamber. The movable ends of the oil cylinders pass through the recovery chamber and are connected to the pistons. The pistons are driven to move back and forth in the compression chamber through the cooperation of the oil cylinders. Specifically, high-temperature resistant oil cylinders can be used to extend the operating stability and service life of the driving device.

[0007] As a further improvement to the above technical solution: the compression chamber is divided into a first chamber and a second chamber by a piston, and a first solenoid valve and a second solenoid valve connected to the first chamber and the second chamber are respectively provided on both sides of the compression chamber, and the first solenoid valve and the second solenoid valve are used to control the drain port and the exhaust port connected to the first chamber and the second chamber.

[0008] As a further improvement of the technical solution: a third solenoid valve is installed on the throat pipe, and its purpose is to control the flow of the throat pipe through the third solenoid valve.

[0009] As an improvement to the above technical solution: a sheet-like breathable steel is arranged inside the throat near one end of the compression chamber. The sheet-like breathable steel refers to a sheet-like component made of breathable steel. The surface of the breathable steel has numerous micropores. The purpose of its arrangement is that the steam carried in the flue gas can converge the droplets in the steam through the air pores of the breathable steel so that the droplets capture each other to form slightly larger droplets, which is helpful for subsequent compression to liquefy the steam and release heat.

[0010] Furthermore: the low-temperature gas outlet of the vortex tube is provided with a waste pipe, the end of which points to the side away from the recovery chamber. The purpose of setting the waste pipe is to guide the low-temperature gas discharged from the vortex tube, so that the low-temperature gas is away from the economizer and the flue gas treatment device, to avoid direct blowing of the low-temperature gas and the reduction of waste heat recovery efficiency.

[0011] Preferably, the diameter of the throat is a, the length of the first chamber and the second chamber is b, and the length of the compression chamber is greater than / equal to a+2b.

[0012] From the above description of the structure of the present invention, it can be seen that compared with the prior art, the present invention has the following advantages: A. The boiler uses high-temperature flue gas as the heat source to achieve the first waste heat recovery. The economizer recovers the second waste heat from the flue gas. The flue gas treatment device compresses the unsaturated flue gas to release the latent heat of condensation to complete the third waste heat recovery. The vortex tube and the recovery chamber then cooperate to achieve the fourth waste heat recovery. The waste heat recovery efficiency is high. B. By rotating the first and second chambers, the flue gas can continuously pass through the throat during the waste heat recovery process, preventing low-temperature flue gas from being retained in the furnace and affecting boiler operation, helping to ensure that the boiler does not need to be shut down during the process; C. When the piston moves away from the chamber connected to the throat pipe, the first solenoid valve and the second solenoid valve connected to the chamber are closed. In the process of the piston moving away from the chamber, negative pressure will be formed to inhale the smoke, which can increase the speed of smoke movement without causing blockage problems. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings: Figure 1 Schematic diagram of the three-dimensional structure of the present invention (viewing angle 1); Figure 2 Schematic diagram of the three-dimensional structure of the present invention (viewing angle 2); Figure 3 Schematic diagram of the three-dimensional structure of the boiler body (viewing angle 1); Figure 4 Schematic diagram of the three-dimensional structure of the boiler body (viewing angle 2); Figure 5 Schematic diagram of the three-dimensional structure of the flue gas treatment device (viewpoint one); Figure 6 A schematic diagram of the three-dimensional structure of the flue gas treatment device (viewpoint 2); Figure 7 A schematic diagram of a partially cutaway structure of the flue gas treatment device (viewpoint one); Figure 8 A schematic diagram of a partially cutaway structure of the flue gas treatment device (viewpoint 2); Figure: Rotary furnace body 1, connecting pipe 101, boiler body 2, economizer 3, flue gas treatment device 4, compression chamber 401, piston 402, drive unit 403, drain port 404, exhaust port 405, vortex tube 406, recovery chamber 407, throat pipe 408, first solenoid valve 409, second solenoid valve 4010, heat exchange tube 4011, fixing frame 4012, first chamber 4013, second chamber 4014, third solenoid valve 4015, waste pipe 4016 DETAILED DESCRIPTION

[0014] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention. Example 1

[0015] See also Figure 1-8 The present invention provides a composite waste heat recovery structure for a sintering rotary furnace, comprising a rotary furnace body 1, a boiler body 2, an energy saver 3 and a flue gas treatment device 4.

[0016] The exhaust pipe of the rotary furnace body 1 is connected to the furnace of the boiler body 2 through the connecting pipe 101; Both ends of the economizer 3 are connected to the flue of the boiler body 2 and the flue gas treatment device 4 respectively.

[0017] The flue gas treatment device 4 includes a compression chamber 401 , a piston 402 , a driving device 403 , a water outlet 404 , an exhaust port 405 , a vortex tube 406 and a recovery chamber 407 .

[0018] The compression chamber 401 is connected to the economizer 3 through the throat pipe 408, and a third solenoid valve 4015 is installed on the throat pipe 408. The piston 402 is located in the compression chamber 401 and matches the compression chamber 401 to form a moving pair along the length direction of the compression chamber 401. The driving device 403 can drive the piston 402 to move. The driving device 403 is specifically an oil cylinder, which is fixedly connected to the boiler body 2 through a fixed frame 4012. The oil cylinders are symmetrically distributed on both sides of the recovery chamber 407, and the movable end of the oil cylinder passes through the recovery chamber 407 and is connected to the piston 402.

[0019] The drain port 404 is located at the bottom end of the compression chamber 401 and communicates with the compression chamber 401 . A first solenoid valve 409 is installed on the drain port 404 .

[0020] The exhaust port 405 is located on the side of the compression chamber 401 and is connected to the compression chamber 401. A second solenoid valve 4010 is installed on the exhaust port 405. The compression chamber 401 is divided into a first chamber 4013 and a second chamber 4014 by the piston 402. The diameter of the throat 408 is a, the length of the first chamber 4013 and the second chamber 4014 is b, the length of the compression chamber 401 is greater than / equal to a+2b, and the first solenoid valve 409 and the second solenoid valve 4010 connected to the first chamber 4013 and the second chamber 4014 respectively are arranged on both sides of the compression chamber 401.

[0021] The air inlet of the vortex tube 406 is connected to the second solenoid valve 4010 , and the low-temperature gas outlet of the vortex tube 406 is provided with a waste pipe 4016 , the end of the waste pipe 4016 points to the side away from the recovery chamber 407 ; The recovery chamber 407 is filled with a heat-conducting medium, and the recovery chamber 407 surrounds the outside of the compression chamber 401 . A heat exchange tube 4011 is provided in the recovery chamber 407 , and one end of the heat exchange tube 4011 is connected to the hot gas outlet of the vortex tube 406 . Example 2

[0022] See also Figure 1-8 The present invention provides a composite waste heat recovery structure for a sintering rotary furnace, comprising a rotary furnace body 1, a boiler body 2, an economizer 3 and a flue gas treatment device 4; The exhaust pipe of the rotary furnace body 1 is connected to the furnace of the boiler body 2 through the connecting pipe 101; The two ends of the economizer 3 are connected to the flue of the boiler body 2 and the flue gas treatment device 4 respectively; The flue gas treatment device 4 includes a compression chamber 401, a piston 402, a driving device 403, a drain port 404, an exhaust port 405, a vortex tube 406 and a recovery chamber 407; The compression chamber 401 is connected to the economizer 3 through a throat pipe 408. A sheet of breathable steel is provided inside the throat pipe 408 at one end near the compression chamber 401. A third solenoid valve 4015 is installed on the throat pipe 408. The piston 402 is located in the compression chamber 401 and matches the compression chamber 401 to form a moving pair along the length direction of the compression chamber 401. The driving device 403 can drive the piston 402 to move. The driving device 403 is specifically an oil cylinder, which is fixedly connected to the boiler body 2 via a fixing frame 4012. The oil cylinders are symmetrically distributed on both sides of the recovery chamber 407. The movable ends of the oil cylinders pass through the recovery chamber 407 and are connected to the piston 402. The drain port 404 is located at the bottom of the compression chamber 401 and communicates with the compression chamber 401 . A first solenoid valve 409 is installed on the drain port 404 . Exhaust port 405 is located on the side of compression chamber 401 and communicates with compression chamber 401. A second solenoid valve 4010 is installed on exhaust port 405. Compression chamber 401 is divided into a first chamber 4013 and a second chamber 4014 by piston 402. The diameter of throat pipe 408 is a, and the lengths of first chamber 4013 and second chamber 4014 are b. The length of compression chamber 401 is greater than or equal to a + 2b. A first solenoid valve 409 and a second solenoid valve 4010 are respectively installed on both sides of compression chamber 401, connected to first chamber 4013 and second chamber 4014, respectively. The air inlet of the vortex tube 406 is connected to the second solenoid valve 4010 , and the low-temperature gas outlet of the vortex tube 406 is provided with a waste pipe 4016 , the end of the waste pipe 4016 points to the side away from the recovery chamber 407 ; The recovery chamber 407 is filled with a heat-conducting medium, and the recovery chamber 407 surrounds the outside of the compression chamber 401 . A heat exchange tube 4011 is provided in the recovery chamber 407 , and one end of the heat exchange tube 4011 is connected to the hot gas outlet of the vortex tube 406 .

[0023] Working principle: The high-temperature flue gas generated by the combustion of the rotary furnace body 1 is introduced into the furnace of the boiler body 2 and directly used as a heat source for the first waste heat recovery. The flue gas carries unsaturated water vapor, and then the flue gas carries steam and leaves the flue and enters the economizer 3 for the second waste heat recovery. Then the flue gas and steam enter the compression chamber 401 for the third waste heat recovery. After the third waste heat recovery is completed, the high-pressure flue gas with a small amount of remaining steam is discharged from the hot gas outlet of the vortex tube 406 into the recovery chamber 407 for the fourth waste heat recovery. After the fourth waste heat recovery is completed, it can be discharged into the air preheater of the boiler or directly discharged to the outside.

[0024] When the flue gas generated by combustion inside the boiler body 2 carries unsaturated steam and enters the compression chamber 401 through the throat 408 for the third waste heat recovery, the flue gas is first squeezed by the piston 402. During this process, the first solenoid valve 409 and the second solenoid valve 4010 are closed to ensure sealing and ensure that the unsaturated steam is compressed into supersaturated steam. The volume of the steam squeezed by the piston 402 becomes smaller, so that the steam is compressed and phase-changed into liquid. During the phase change process, heat is released in the form of latent heat of condensation, which can be transferred to the recovery chamber 407 through heat transfer and collected.

[0025] When the third waste heat recovery is completed, the flue gas with a small amount of remaining steam is compressed and has a higher pressure. At this time, the second solenoid valve 4010 is opened to introduce the pressurized flue gas into the vortex tube 406. The flue gas is divided into hot air and cold air in the vortex tube 406, and leaves from the hot air outlet of the vortex tube 406 and the exhaust pipe 4016 respectively. The hot air is introduced into the recovery chamber 407 through the heat exchange pipe 4011 to exchange heat with the heat transfer medium, thereby completing the fourth waste heat recovery.

[0026] The above operations are performed reciprocally in the first chamber 4013 and the second chamber 4014 to realize waste heat recovery of the flue gas. Since the piston 402 can move in the compression chamber 401, when the first chamber 4013 is performing flue gas compression, the flue gas generated by the boiler combustion can continuously enter the second chamber 4014 to prepare for the next compression. When the second chamber 4014 is performing flue gas compression, the flue gas generated by the boiler combustion can continuously enter the first chamber 4013 to prepare for the next compression, which will not affect the combustion of the boiler and the steam discharge.

[0027] When the piston 402 moves away from the chamber connected to the throat 408, the first solenoid valve 409 and the second solenoid valve 4010 connected to the chamber are closed. In the process of the piston 402 moving away from the chamber, negative pressure will be formed to inhale the smoke, which can increase the speed of smoke movement without any blockage problem.

[0028] The control method of the present invention is to achieve automatic control through an external controller. The control circuit of the controller can be implemented by simple programming by technicians in this field. The provision of power is also common knowledge in this field. The present invention is mainly used to protect mechanical devices, so the control method and circuit connection are no longer explained in detail in the present invention.

[0029] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0030] Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first," "second," or "third" may explicitly or implicitly include one or more of such features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0031] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A composite waste heat recovery structure for a sintering rotary kiln, characterized by: It includes a rotary kiln main body (1), a boiler main body (2), an energy saver (3) and a flue gas treatment device (4); The smoke exhaust pipe of the rotary furnace body (1) is connected to the furnace of the boiler body (2) through a connecting pipe (101); The two ends of the energy saver (3) are respectively connected to the flue of the boiler body (2) and the flue gas treatment device (4); The flue gas treatment device (4) comprises a compression chamber (401), a piston (402), a driving device (403), a drainage port (404), an exhaust port (405), a vortex tube (406), and a recovery chamber (407); The compression chamber (401) is connected to the energy saver (3) through the throat (408); the piston (402) is located in the compression chamber (401) and matches the compression chamber (401) to form a moving pair along the length direction of the compression chamber (401); the driving device (403) can drive the piston (402) to move; The drain port (404) is located at the bottom end of the compression chamber (401) and is in communication with the compression chamber (401). A first solenoid valve (409) is installed on the drain port (404); The exhaust port (405) is located on the side of the compression chamber (401) and is in communication with the compression chamber (401). A second solenoid valve (4010) is installed on the exhaust port (405); The air inlet of the vortex tube (406) is in communication with the second solenoid valve (4010); The recovery chamber (407) is filled with a heat-conducting medium. The recovery chamber (407) surrounds the outside of the compression chamber (401). A heat exchange tube (4011) is provided in the recovery chamber (407), and one end of the heat exchange tube (4011) is connected to the hot gas outlet of the vortex tube (406).

2. The composite waste heat recovery structure of a sintering rotary furnace according to claim 1, characterized in that: The driving device (403) is an oil cylinder, which is fixedly connected to the boiler body (2) via a fixing frame (4012). The oil cylinders are symmetrically distributed on both sides of the recovery chamber (407), and the movable ends of the oil cylinders pass through the recovery chamber (407) and are connected to the piston (402).

3. The composite waste heat recovery structure of a sintering rotary furnace according to claim 1, characterized in that: The compression chamber (401) is divided into a first chamber (4013) and a second chamber (4014) by the piston (402). A first solenoid valve (409) and a second solenoid valve (4010) connected to the first chamber (4013) and the second chamber (4014) are provided on both sides of the compression chamber (401).

4. A composite waste heat recovery structure for a sintering rotary furnace according to any one of claims 1 to 3, characterized in that: A third solenoid valve (4015) is installed on the throat pipe (408).

5. The composite waste heat recovery structure of a sintering rotary furnace according to any one of claims 1 to 3, characterized in that: A sheet of breathable steel is provided inside one end of the throat pipe (408) close to the compression chamber (401).

6. A composite waste heat recovery structure for a sintering rotary furnace according to any one of claims 1 to 3, characterized in that: The low-temperature gas outlet of the vortex tube (406) is provided with a waste discharge pipe (4016), and the end of the waste discharge pipe (4016) points to a side away from the recovery chamber (407).

7. The composite waste heat recovery structure of a sintering rotary furnace according to claim 3, characterized in that: The diameter of the throat (408) is a, the length of the first chamber (4013) and the second chamber (4014) is b, and the length of the compression chamber (401) is greater than / equal to a+2b.

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