High-temperature flue gas and air heat exchanger for rotary kiln

Abstract

The utility model discloses a high-temperature flue gas and air heat exchanger for a rotary kiln, which relates to the technical field of heat exchangers and comprises an inlet flue, a heat exchanger body communicated with the bottom of the inlet flue, an outlet flue communicated with the bottom of the heat exchanger body and an ash hopper communicated with the bottom of the outlet flue. An air outlet channel is arranged above the air inlet channel and communicates with the top end of the heat exchanger body, and a plurality of partition plates which are arranged in a staggered mode are arranged in an inner cavity of the heat exchanger body. The heat exchanger is arranged in an open-air vertical mode, smoke enters from the horizontal top, after high-temperature smoke enters the heat exchanger, the high-temperature smoke vertically and longitudinally scours the heat exchanger tube set downwards, heat is promoted to be transmitted to the heat exchanger tube set, and air horizontally enters the heat exchanger tube set from the lower portion of the heat exchanger and transversely scours the heat exchanger tube set between the upper tube plate and the lower tube plate. The heat exchange efficiency is improved, heat conduction is met, and the effects that the structure is small in occupied area and low in material cost are achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of heat exchangers, in particular to a rotary kiln high-temperature flue gas-air heat exchanger. Background Technique

[0002] With the continuous increase in energy use, the effective utilization of energy has attracted more and more attention; currently, a large amount of high-temperature flue gas is generated during the use of rotary kilns, causing a part of the heat generated in the rotary kilns to be carried away by the flue gas, resulting in great waste; therefore, effectively recovering the heat in the flue gas is a better method to improve the energy utilization rate, and the most common way is to recover the waste heat of the flue gas through a heat exchanger.

[0003] The Chinese patent discloses an air heat exchanger for recovering waste heat of high-dust flue gas, with the publication number CN208458520U. The technical solution disclosed in this patent document is as follows: It includes a flue gas duct box provided with a flue gas inlet and a flue gas outlet. Inside the flue gas duct box, multiple vertically arranged U-shaped heat exchange tubes are provided, and the air inlet end and the air outlet end of the U-shaped heat exchange tubes are installed on the top of the flue gas duct box through tube plates. To solve the problem that the dust deposited on the outer surface of the heat exchange tubes is not easy to clean, the prior art is to use a method of arranging multiple vertically arranged U-shaped heat exchange tubes inside the flue gas duct box, and it is not easy for dust to deposit on the surface of the U-shaped heat exchange tubes. The following problems exist in the prior art: The structure of multiple vertically arranged U-shaped heat exchange tubes is likely to cause the overall horizontal setting of the heat exchanger to occupy a large area. At the same time, due to the large horizontal setting area, it is necessary to cooperate with the installation of multiple ash hoppers and ash discharge pipes, and the material cost will increase accordingly, and the overall installation space will also increase. Content of the Utility Model

[0004] The purpose of the utility model is to provide a rotary kiln high-temperature flue gas-air heat exchanger to solve the problems raised in the above background technique.

[0005] To solve the above technical problems, the technical solution adopted by the utility model is:

[0006] A rotary kiln high-temperature flue gas-air heat exchanger includes an inlet flue, a heat exchanger body connected to the bottom of the inlet flue, an outlet flue connected to the bottom of the heat exchanger body, and an ash hopper connected to the bottom of the outlet flue. An air inlet duct is connected to the bottom end of the heat exchanger body. An air outlet duct is arranged above the air inlet duct, and the air outlet duct is connected to the top end of the heat exchanger body. The inner cavity of the heat exchanger body is provided with a plurality of staggered partitions, and a connecting pipe for connection is arranged between the air inlet duct and the air outlet duct, and an air butterfly valve is arranged on the connecting pipe.

[0007] Preferably, tube sheets are respectively connected to the upper and lower ends of the inner cavity of the heat exchanger. A number of openings are distributed on the surface of the tube sheets, and a heat exchanger tube group is welded in the number of openings. Through the design of the heat exchanger tube group, it is promoted that after the flue gas enters the inlet flue through the flue gas inlet, it turns 90° and vertically flushes down the heat exchanger tube group.

[0008] Preferably, the inlet flue communicates with the outlet flue through the heat exchanger tube group. It is convenient for the high-temperature flue gas to enter the outlet flue, and at the same time, it is beneficial for the ash accumulation part in the flue gas to be discharged through the ash discharge port at the bottom of the ash hopper.

[0009] Preferably, three partition plates are provided, and the three partition plates divide the inner cavity of the heat exchanger into an M-shaped air flow channel. Through the design of the M-shaped air flow channel, when the air enters horizontally from the lower part of the heat exchanger body outside the heat exchanger tube group, it turns 180° after passing through the partition plate in the middle of the tube sheet and is horizontally heated at the upper part and then leaves the heat exchanger body, so as to improve the heat transfer efficiency by transverse flushing.

[0010] Preferably, the three partition plates are all penetrated by the heat exchanger tube group. It ensures the sealing between the partition plate and the heat exchanger tube group and is beneficial for the transverse flushing of the low-temperature air.

[0011] Preferably, a flue gas inlet is connected to the surface of the inlet flue, and the flue gas inlet is horizontally arranged. Through the horizontal design of the flue gas inlet, it is beneficial for the flue gas to enter the inlet flue and then enter the heat exchanger body at 90°, reducing the situation of flue gas backflow.

[0012] Preferably, a flue gas outlet is connected to the surface of the outlet flue, and the flue gas outlet is horizontally arranged. The flue gas outlet is parallel and offset from the flue gas inlet.

[0013] Due to the adoption of the above technical solutions, the technical progress achieved by the present utility model compared with the prior art is:

[0014] 1. The present utility model provides a rotary kiln high-temperature flue gas-air heat exchanger to solve the problems of large floor area and high material cost of the existing structure with an overall horizontal arrangement. By arranging the heat exchanger in an open-air vertical layout, the flue gas enters from the horizontal top, and after the high-temperature flue gas enters, it vertically flushes down the heat exchanger tube group longitudinally, promoting the heat transfer to the heat exchanger tube group, while the air enters horizontally from the lower part of the heat exchanger outside the heat exchanger tube group and transversely flushes the heat exchanger tube group between the upper and lower tube sheets, improving the heat transfer efficiency, meeting the heat conduction, and achieving the effects of small floor area and low material cost of the structure.

[0015] 2. The present utility model provides a rotary kiln high-temperature flue gas-air heat exchanger to solve the problem of low heat transfer efficiency. By using multiple partition plates to divide the inner cavity of the heat exchanger into an M-shaped air flow channel, it is promoted that the low-temperature air repeatedly transversely flushes the heat exchanger tube group outside the heat exchanger tube group, improving the heat conduction and the heat transfer efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic diagram of the overall structure of the present utility model;

[0017] Figure 2 is a schematic left view structure diagram of the overall of the present utility model;

[0018] Figure 3 is the present utility model Figure 1 partial sectional structure diagram;

[0019] Figure 4 is the present utility model Figure 2 partial sectional structure diagram.

[0020] In the figure: 1, inlet flue; 11, flue gas inlet; 2, heat exchanger body; 21, heat exchanger tube group; 22, tube sheet; 3, outlet flue; 31, flue gas outlet; 4, ash hopper; 5, air inlet duct; 6, air outlet duct; 7, partition plate; 8, connecting pipe; 9, air butterfly valve. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] The following further describes the present utility model in detail with reference to embodiments:

[0022] As Figures 1-4 shown, the present utility model provides a rotary kiln high-temperature flue gas-air heat exchanger, including an inlet flue 1, a heat exchanger body 2 connected to the bottom of the inlet flue 1, an outlet flue 3 connected to the bottom of the heat exchanger body 2, and an ash hopper 4 connected to the bottom of the outlet flue 3. An air inlet duct 5 is connected to the bottom end of the heat exchanger body 2. An air outlet duct 6 is arranged above the air inlet duct 5. The air outlet duct 6 is connected to the top end of the heat exchanger body 2. A plurality of staggered partition plates 7 are arranged in the inner cavity of the heat exchanger body 2. A connecting pipe 8 for connection is arranged between the air inlet duct 5 and the air outlet duct 6. An air butterfly valve 9 is arranged on the connecting pipe 8.

[0023] Further, the air inlet duct 5 is made of carbon steel pipe, and the air outlet duct 6 is made of 304 stainless steel pipe; on the inner sides of the inlet flue 1, the heat exchanger body 2 and the outlet flue 3, castable and heat-insulating aluminosilicate fiber materials are laid according to the temperature to protect the shell and the like from being deformed by the roasting of high-temperature flue gas.

[0024] As Figure 3As shown in the figure, tube sheets 22 are respectively connected to the upper and lower ends of the inner cavity of the heat exchanger body 2. A number of openings are distributed on the surface of the tube sheets 22, and a heat exchanger tube group 21 is welded in the number of openings. The inlet flue 1 and the outlet flue 3 communicate through the heat exchanger tube group 21. The heat exchanger tube group 21 uses tubes made of high-temperature resistant 316L material with a diameter of φ51x1.5 and is vertically arranged, so that the flue gas turns 90° vertically downward to scour the heat exchanger tube group 21 after entering the inlet flue 1 at the flue gas inlet 11.

[0025] Furthermore, as Figure 4 shown in the figure, a number of partitions 7 are all penetrated by the heat exchanger tube group 21, and there are three partitions 7. The three partitions 7 divide the inner cavity of the heat exchanger body 2 into an M-shaped air flow channel. Through the design of the M-shaped air flow channel, when air horizontally enters the outside of the heat exchanger tube group 21 from the lower part of the heat exchanger body 2, it turns 180° after passing through the partition 7 in the middle of the tube sheet 22 and is heated horizontally at the upper part and then leaves the heat exchanger body 2. In this way, the transverse scouring and the longitudinal scouring can improve the heat exchange efficiency.

[0026] As Figure 1 、 Figure 2 shown in the figure, a flue gas inlet 11 is connected to the surface of the inlet flue 1. The flue gas inlet 11 is horizontally arranged. A flue gas outlet 31 is connected to the surface of the outlet flue 3. The flue gas outlet 31 is horizontally arranged. Through the horizontal design of the flue gas inlet 11, it is beneficial for the flue gas to enter the heat exchanger body 2 at 90° after entering the inlet flue 1, reducing the situation of flue gas backflow.

[0027] Next, the working principle of this rotary kiln high-temperature flue gas-air heat exchanger will be specifically described.

[0028] As Figures 1-4 shown in the figure, this heat exchanger is arranged vertically outdoors and intakes air at the horizontal top flue gas inlet 11. After the flue gas enters the inlet flue 1, it turns 90° vertically downward to scour the heat exchanger tube group 21, promoting the longitudinal scouring of the high-temperature flue gas in the heat exchanger tube group 21, transferring heat to the heat exchanger tube group 21, and then the flue gas vertically passes through the inside of the heat exchanger tube group 21 and enters the lower outlet flue 3 and ash hopper 4, and turns 90° horizontally to leave the heat exchanger. And the ash accumulation part in the flue gas is discharged from the heat exchanger through the ash discharge port at the bottom of the ash hopper 4; and during this period, air horizontally enters the outside of the heat exchanger tube group 21 from the lower air inlet channel 5 of the heat exchanger, and horizontally scours the heat exchanger tube group 21 through a number of partitions 7 between the upper and lower tube sheets 22. In this way, the air is heated in the air flow channel and leaves the heat exchanger body 2 through the air outlet channel 6, improving the heat exchange efficiency.

[0029] It should be noted that in the description of the present disclosure, unless otherwise clearly specified and defined, the terms "installed", "connected", and "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present disclosure can be understood according to specific circumstances.

[0030] The above has generally described the present invention in detail, but based on the present invention, some modifications or improvements can be made, which are obvious to those of ordinary skill in the art. Therefore, modifications or improvements made without departing from the spirit of the present invention are within the protection scope of the present invention.

Claims

1. A rotary kiln high temperature flue gas air heat exchanger, characterized in that: It includes an inlet flue, a heat exchanger body connected to the bottom of the inlet flue, an outlet flue connected to the bottom of the heat exchanger body and an ash hopper connected to the bottom of the outlet flue, the bottom end of the heat exchanger body is connected to an air inlet channel, an air outlet channel is arranged above the air inlet channel, the air outlet channel is connected to the top of the heat exchanger body, and the inner cavity of the heat exchanger body is provided with a plurality of staggered partitions, and a connecting pipe for connection is provided between the air inlet channel and the air outlet channel, and an air butterfly valve is arranged on the connecting pipe.

2. The rotary kiln high temperature flue gas to air heat exchanger according to claim 1, characterized in that: The upper and lower ends of the inner cavity of the heat exchanger body are respectively connected with tube sheets, and a plurality of openings are distributed on the surface of the tube sheets, and heat exchanger tube groups are welded in a plurality of the openings.

3. The rotary kiln high temperature flue gas to air heat exchanger according to claim 2, characterized in that: The inlet flue and the outlet flue are communicated through a heat exchanger tube group.

4. The rotary kiln high temperature flue gas to air heat exchanger according to claim 1, characterized in that: Three partitions are provided, and the three partitions divide the inner cavity of the heat exchanger body into M-shaped air flow channels.

5. The rotary kiln high temperature flue gas to air heat exchanger according to claim 2, characterized in that: The three partitions are all penetrated by the heat exchanger tube group.

6. The rotary kiln high temperature flue gas to air heat exchanger according to claim 1, characterized in that: The surface of the inlet flue is connected with a smoke inlet, and the smoke inlet is arranged horizontally.

7. The rotary kiln high temperature flue gas to air heat exchanger according to claim 1, characterized in that: The surface of the outlet flue is connected with a smoke outlet, and the smoke outlet is arranged horizontally.

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